G

C
JD750

D
Crawler
Bulldozer

TECHNICAL MANUAL
JD750 Crawler
Bulldozer

TM1136 (01MAR84) English

0 1 M A R 8 4

John Deere Dubuque Works

T M 1 1 3 6

TM1136 (01MAR84)
LITHO IN U.S.A.
ENGLISH
JD750 Crawler Bulldozer General lnforma tion I
TM- 1736 (Mar-84) Contents and Index - I-1

JD750 Crawler Bulldozer

Technical Manual
TM-1 136 (Mat-64)

SECTIONAL CONTENTS OF THIS MANUAL

Section 1 _ Wheels and Tires and Tracks

Section 2 - Axles and Suspension System

Section 3 - Transmission

Section 4 - Engine

Section 5 - Engine Auxiliary Systems

Section 6 - Torque Converter

Section 7 - Traction or Disconnect Clutch

Section 8 - Transfer Drive

Section 9 - Steering Systems

Section 10 - Service Brakes

Section 11 - Parking-Emergency Brakes

Section 13 - Miscellaneous Vehicle

Section 15 - Equipment Attaching

Copyright@ 1984
Previous Editions DEERE 81 COMPANY
Copyright@ 1979 DEERE & COMPANY Moline, Illinois
Copyright@ 1978 DEERE & COMPANY All Rights Reserved
Copyright@ 1977 DEERE & COMPANY
Copyright@ 1975 DEERE & COMPANY

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 I General lnformation JD750 Crawler Bulldozer
l-2 Contents and index TM- 1136 (Apr-79)

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JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Nov- 75) Contents and index I-3

SECTIONAL CONTENTS (Continued)

Section 16 - Electrical Systems

Section 17 - Frame, Chassis or Supporting Structure-

Section 18 - Operator’s Station

Section 19 - Sheet Metal and Styling

Section 21 - Main Hydraulic System

Section 22 - Pneumatic Systems

Section 30 - Winch

Section 31 - Loader

Section 32 - Dozer

Section 33 - Backhoe and Excavator

Section 34 - Grading Device

Section 35 - Scraper and Haulage Device

Section 36 - Conveyor and Elevating Device

Section 37 - Arch or Boom

Section 38 - Grapple or Clamp

Section 39 - Shear

Section 40 PTO or Winch Drive

Continued on page 5

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 I General information JD750 Crawler Bulldozer
I-4 Contents and Index TM- 1136 (Nov-75)

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JD750 Crawler Bulldozer General Information I
TM- 1136 (Nov- 75) Contents and Index I-5

SECTIONAL CONTENTS (Continued)

Section 41 - Misc. Function Mechanical Drive

Section 42 - Ground Conditioning Tool

Section 43 - Swing, Rotation or Pivoting System

Section 44 - Cutting Mechanism

Section 45 - Forklifts

Section 90 - System Testing

The specifications and design information contained in

this manual were correct at the time it was printed. It is John
Deere’s policy to continually improve and update our ma-
chines. Therefore, the specifications and design information
are subject to change without notice. Wherever applicable,
specifications and design information are in accordance with
SAE and ICED standards.

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I General Information JD750 Crawler Bulldozer
I-6 Contents and Index TM- 1136 (Nov-75)
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JD 750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Contents and index l-7

SECTION AND GROUP CONTENTS OF THIS MANUAL

SECTION I - GENERAL INFORMATION SECTION 5 - ENGINE AUXILIARY SYSTEMS

Group I - Contents and Index Group 0505 - Cold Weather Starting Aids
Group II - Introduction and Safety Information Group 0510 - Engine Cooling System
Group Ill - General Specifications Group 0515 - Speed Controls
Group IV - Predelivery, Delivery and After-Sale Ser- Group 0520 - Intake System
vices Group 0530 - External Exhaust Systems
Group V - Fuels and Lubricants Group 0540 - Mounting Frame
Group 0560 - External Fuel Supply System
SECTION 1 - TRACKS Group 0599 - Specifications and Special Tools
Group 0130 - Track Systems
Group 0199 - Specifications and Special Tools SECTION 8 - TRANSFER DRIVE
Group 0841 - Housing and Covers
SECTION 2 - AXLES AND SUSPENSION Group 0851 - Gears, Shafts, Bearings
SYSTEMS Group 0899 - Specifications and Special Tools
Group 0201 - Drive Axle Housing
Group 0250 - Axle Shaft, Bearings and Reduction SECTION 11 - PARKING-EMERGENCY BRAKE
Gears Group 1111 - Active Elements
Group 0299 - Specifications and Special Tools Group 1115 - Controls Linkage
Group 1160 - Parking Brake Hydraulics
SECTION 3 - TRANSMISSION Group 1199 - Specifications and Special Tools
Group 0315 - Controls
Group 0325 - Input Drive Shafts and U-Joints SECTION 15 - EQUIPMENT A-l-l-ACHING
Group 0360 - Transmission Hydraulics Group 1511 - Drawbar
Group 0370 - Clutch Disconnect and Controls Group 1512 - Towbar
Group 0399 - Specifications and Special Tools
SECTION 16 - ELECTRICAL SYSTEMS
SECTION 4 - ENGINE Group 1671 - Batteries, Supports and Cables
Group 0400 - Engine Removal and Installation Group 1672 - Alternator, Regulator and Charging
Group 0401 - Crankshaft and Main Bearings System Wiring
Group 0402 - Camshaft and Valve Actuating Means Group 1673 - Lighting System
Group 0403 - Connecting Rods and Pistons Group 1674 - Wiring Harness and Switches
Group 0404 - Cylinder Block Group 1699 - Specifications and Special Tools
Group 0407 - Engine Oiling System
Group 0408 - Ventilating System SECTION 17 - FRAME, CHASSIS OR
Group 0409 - Cylinder Head and Valves SUPPORTING STRUCTURE
Group 0410 - Exhaust Manifold Group 1741 - Main Frame
Group 0413 - Fuel Injection System Group 1746 - Frame Bottom Guards
Group 0416 - Turbocharger
Group 0417 - Water Pump SECTION 18 - OPERATOR’S STATION
Group 0418 - Thermostats, Housings and Piping Group 1806 - Safety Equipment
Group 0419 - Engine Oil Cooler Group 1808 - Comfort and Convenience Items
Group 0420 - Fuel Filter Group 1810 - Operator Enclosure
Group 0421 - Fuel Transfer Pump Group 1821 - Seat
Group 0422 - Starting System Group 1823 - Instruments and Indicators
Group 0433 - Flywheel, Housing and Fasteners Group 1824 - External Engine Speed Control
Group 0499 - Specifications and Special Tools Group 1830 - Heating and Air Conditioning
Group 1899 - Specifications and Special Tools

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I General lnforma tion JD750 Crawler Bulldozer
l-8 Con tents and Index TM- 1136 (Mar-84)

SECTION AND GROUP CONTENTS OF THIS MANUAL-Continued

SECTION 19 - SHEET METAL AND STYLING SECTION 90 - SYSTEM TESTING

Group 1910 - Hood or Engine Enclosure Group 9005 - General Information - Seven Basic
Group 1921 - Grille and Grille Housing Steps of Diagnosis and Testing and
Operational Checkout Procedure
SECTION 32 - DOZER Group 9010 - Engine
Group 3201 _ Blade Group 9015 - Electrical System
Group 3215 - Controls Linkage Group 9020 - Power Train
Group 3242 - Sub Frame Group 9025 - Hydraulic System (Flow Meter)
Group 3243 - Movable Frames Group 9025A - Hydraulic System (Analyzer)
Group 3260 - Dozer Hydraulics Group 9026 - Hydrostatic System
Group 3299 - Specifications and Special Tools Group 9030 - Miscellaneous Components
Group 9031 - Heating and Air Conditioning
SECTION 42 - GROUND CONDITIONING TOOL Group 9035 - Specifications and Special Tools
Group 4201 - Blade, Teeth, Shanks
Group 4215 - Controls Linkage
Group 4260 - Hydraulic System

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 JD750 Crawler Bulldozer General Information I
TM- 1136 (Apr- 79) Contents and Index l-9

ALPHABETICAL INDEX

A Air conditioning system testing - Continued

Adapter, starting aid ...................... 0505-4 Discharging the system . . . . . . . . . . . . . . . . 9031-l 3
Accessories testing ...................... 901536 Electrical testing. . . . . . . . . . . . 9015-35, 9031-9
After-sale inspection .............. I-IV-,19 - I-IV-32 Evacuating the system . . . . . . . 9031-13 - 9031-15
Air cleaner. ............................ I-IV-23 Flushing the system . . . . . , . . . 9031-19 - 9031-20
Air intake hose. ........................ I-IV-23 Inspecting refrigerant hoses and
Alternator-fan compressor belt tubing..............................9031-2 0
tension. ..................... I-IV-23 - I-IV-25 Isolating compressor from system ....... 9031-l 8
Batteries .............................. I-IV-29 Leak testing ................ 9.031-19 - 9031-20
Cab air filter ........................... I-IV-29 Operational test ....................... 9031-l 1
Charging system ....................... I-IV-31 Pressure gauges ...................... 9031-l 2
Engine crankcase oil and filter. .......... I-IV-20 Safety precautions. .................... 9031-12
Final drive housing oil level ............. I-IV-22 Schematic ............................. 9031-5
Fluid leakage .......................... I-IV-32 Temperature pressure chart ............ 9031-l 7
Fuel tank sump ........................ I-IV-25 Theory of operation. ........... .9031-5 - 9031-6
Hydraulic oil level ...................... I-IV-21 Air filters. ............................... 1830-32
Hydrostatic transmission oil. ............. I-IV-21 Air intake system .............. 1830-31 - 1830-32
Indicator lights and gauges. ............. I-IV-29 Air filters ............................. 1830-32
Lubrication. .................... I-IV-28 - I-IV-29 Pressurizer blowers and _
Park brake ............................ I-IV-31 switch. ................... 1830-31 - 1830-32
Raditor coolant level. ................... I-IV-25 Air intake test system ............ 9010-1, 9010-15
Splitter gearbox oil level ................ I-IV-22 Testing ............................... 9010-15
Track tension adjustment. ....... I-IV-26 - I-IV-27 Theory ................................ 9010-l
Track shoe cap screws ................. I-IV-27 Air restriction indicator ............ .0520-l, 1823-3
Air cleaner assembly. ............ .0520-l - 0520-2 Alternator and regulator,
Components ........................... 0520-l 16 amp .................... 1672-13 - 1672-24
Air conditioning system. ......... 1830-5 - 1830-32 Assembly. .................. 1672-22 - 1672-23
Air filters ............................. 1830-31 Component tests ............ 1672-19 - 1672-21
Compressor ................. 1830-5 - 1830-20 Components .......................... 1672-15
Compressor relief valve ................ 1830-28 Explanatory information ...... 1672-13 - 1672-14
Condenser. ................. 1830-22 - 1830-23 Repair ..................... 1672-15 - 1672-18
Evaporator. ........................... 1830-25 Test after assembly ................... 1672-23
Expansion valve. ...................... 1830-26 Alternator and regulator, 42 amp . 1672-1 - 1672-12
High temperature switch ............... 1830-30 Assembly ................... 1672-11 - 1672-12
Pressurizer blowers and Component tests ............. 1672-7 - 1672-11
switch. ................... 1830-31 - 1830-32 Components ........................... 1672-3
Receiver - dryer. ............ 1830-23 - 1830-24 Explanatory information ........ .1672-l - 1672-2
Refrigerant couplings .................. 1830-29 Installation ............................ 1672-12
Thermal fuse and superheat Removal .............................. 1672-2
shut-off switch ...................... 1830-21 Repair ....................... .1672-2 - 1672-7
Thermostatic temperature control Automatic control valve ....... .0360-62 - 0360-64,
switch. ................... 1830-27 - 1830-28 0360273 - 0360-75
Air conditioning system testing ........... .9015-35, Automatic control valve shut-off
9031-2 - 9031-20 valve ........................ 0360-62, 0360-73
Adding refrigerant-12 to the Automatic control valve shut-off
system ................... 9031-16 - 9031-17 valve control .......................... 0315-14
Charging the system. ........ 9031-15 - 9031-16 Components .......................... 0315-14
Component location ........... .9031-2 - 9031-4
Diagnosis and testing .......... .9031-7 - 9031-8
1 Diagnosis flow chart .................... 9031-9

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 I General information JD750 Crawler Bulldozer
l-10 Contents and Index TM- 1136 (Apr- 79)

Automatic control valve variable Brush shield .............................. 1910-7

orifice ..................... .0360-65 - 0360-66, Bulldozer blade. ................. .3201-3 - 3201-4
0360-76 - 0360-78 Bushings, engine starting system. .......... 0422-7
Assembly. .................. 0360-76 _ 0360-78 Bypass valve, transmission ..... 0360-33 - 0360-34
Disassembly ................ 0360-65 - 0360-66
Automatic control valve variable C
orifice linkage ............... 0315-l 1 - 0315-12 Cab ............................. .1810-l - 1810-6

q
Components .......................... 0315-12 Components ........................... 1810-5
Auxiliary control linkage .......... .4215-l - 4215-4 Cab relay. ..... , ......................... 1823-6
Adjustment ............................ 4215-4 Camshaft and valve actuating
Components .................. .4215-l - 4215-4 means ....................... .0402-l - 0402-6
Axle shaft, bearings and reduction Components ................... .0402-l, 0402-3
gears ....................... 0250-l - 0250-10 Timing gear train. ........... .0402-4 - 0402-5
Final drive housing cover with Front plate and timing
gears and shafts. ........... .0250-4 - 0250-7 gear cover ............. .0402-4 - 0402-5
Parking brake assembly. ...... 0250-8 - .0250-10 Gear train backlash ................ 0402-4
Assembly ................. 0250-8 - 0250-10 Idler gears ........................ 0402-4
Components. ........................ 0250-9 Chain, track. .................. 0130-24 - 0130-31
Planet housing with pinions Charge pump, transmission. .... 0360-26 - 0360-27
and shafts .................... .0250-2 - 0250-3 Charging circuit testing ......... 9015-26 - 9015-31
Components. ........................ 0250-3 Cigar lighter. ............................. 1808-l
Circuit breakers .......................... 1674-3
B Clutch coil and housing ........ 1830-15 - 1830-16
Basic engine testing ..................... 9010-10 Clutch, engine disconnect:
Batteries, supports and cables .... 1671-3 - 1671-7, Controls ...................... .0370-l _ 0370-3
9015-19 Components. ............... .0715-2 - 0715-3
Charging .............................. 1671-7 Elements ..................... .0370-4 - 0370-6
Inspection .................... .1671-4 - 1671-5 Components. ............... .0370-4 - 0370-6
Checking electrolyte level ............. 1671-5 Cold weather starting aids. ....... .0505-3 - 0505-4
Cleaning ............................ 1671-4 Starting aid adapter, line
Battery disconnect switch. ................. 1674-2 and nozzle .......................... 0505-4
j Blade, dozer .................... .3201-3 - 3201-6 Starting aid solenoid. ................... 0505-3
Bleeding fuel injection pump ............... 0413-3 Starting aid switch ............. .0505-3 - 0505-4
Block, cylinder .................. .0404-l - 0404-2 Comfort and convenience items. ........... 1808-l
Block diagram: Component location:
Electrical system ....................... 9015-5 Air conditioning system ........ .9031-2 - 9031-4
j Hydraulic system (flow meter) 9025-12 - 9025-13 Electrical system .............. .9015-2 - 9015-4
Hydrostatic system .................... 9026-18 Engine ....................... .9010-2 - 9010-4
Power train ............................ 9020-5 Hydraulic system (flow meter) .. .9025-2 - 9025-3
Blower motors. ................ 1830-31 - 1830-32 Hydrostatic system .......... 9026-32 - 9026-34
Body connectors ......................... 1674-l Power train ................... .9020-2 - 9020-4
Bottom guards, frame ............ .1746-l - 1746-2 Compressor. ................... 1830-5 - 1830-20
Brake, emergency parking: Components .................. .1830-5 - 1830-7
Controls, linkage .............. .1115-3 - 1115-5 Repair ...................... 1830-8 - 1830-19
Hydraulics ................... ..1160- 1 - 1160-4 Checking and adding
Brush assembly, alternator, compressor oil. ................... 1830-l 6
16 amp ..................... 1672-13, 1672-16, Clutch coil and housing. ... 1830-15 - 1830-16
1672-l 9, 1672-23 Compressor pulley and
Brush assembly, alternator, bearing ................ 1830-14 - 1830-15
42amp .............................. .1672-l, Compressor shaft seal. .... 1830-10 - 1830-13
1672-7 - 1672-8, Leak testing compressor ... 1830-18 - 1830-l 9
1672-12 Servicing. .......................... 1830-17

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JD750 Crawler Bulldozer General Information I
TM- 1136 (Apr- 79) Contents and index I-11

Compressor pulley and Crankshaft and main bearings .... .0401-l - 0401-5
bearing ..................... 1830-14 - 1830-15 Installation .................... .0401-4 - 0401-5
Compressor relief valve .............. : ... 1830-28 Front oil seal ........................ 0401-5
Compressor shaft seal ......... 1830-10 - 1830-13 Main bearing ....................... _ 0401-4
Condenser. ................... 1830-22 - 1830-23 Rear oil seal. ........................ 0401-5
Connecting rods and pistons. ..... .0403-l - 0403-4 Rear wear ring ....................... 0401-4
Components .................. .0403-2 - 0403-3 Removal .............................. 0401-l
Contiol valve, dozer hydraulic. ... 3260-8 - 3260~15 Re;pair ....................... .0401-l - 0401-3
Control valve, transmission ..... 0360-57 - 0360-84 Crankshaft damper ................... 0401-3
Assembly. .................. 0360-72 - 0360-83 Crankshaft gear. ..................... 0401-l m
Automatic control valve .... 0360-73 - 0360-75 Crankshaft rear oil seal,
Automatic control valve shut- housing and wear sleeve ........... 0401-3
off valve .......................... 0360-73 Front oil sleeve and wear
Automatic control valve sleeve: ........................... 0401-3
variable orifice. ......... 0360-76 - 0360-78 Main bearings and crankshaft
FNR valve. ............... 0360-81 - 0360-82 journals .................. ,0401-l - 0401-3
Pl over pressure relief valve ......... 0360-72 Cylinder block. .................. .0404-l - 0404-2
P2 pressure regulator valve .......... 0360-72 Cylinder, dozer hydraulic ....... 3260-16 - 3260-24
Port plate and cover Cylinder head and valves ........ .0409-l - 0409-5
assembly .............. 0360-82 - 0360-83 Components ........................... 0409-2
Speed control valve ....... 0360-80 - 0360-81 Cylinder liners. .................. .0404-l - 0404-2
Steering valve ...................... 0360-78
Steering valve lever assembly ........ 0360-79 D
Steering valve orifices ............... 0360-75 Delivery service .......................... I-IV-l 9
Disassembly ................ 0360-59 ‘- 0360-71 Diagnosing malfunctions:
Automatic control valve .... 0360-62 - 0360-64 Air conditioning system ........ .9031-7 - 9031-8
Automatic control valve Electrical system ............. 9015-14 - 9015-6
shut-off valve. .................... 0360-62 Engine ....................... .9010-5 - 9010-7
Automatic control valve Heating system ........................ 9031-l
variable orifice. ......... 0360-65 - 0360-66 Hydraulic system (flow meter) 9025-17 - 9025-19 I
FNR valve. ............... 0360-66 - 0360-70 Hydrostatic system ......... 9026-39 - 9026-100
Pl over pressure relief valve. ........ 0360-61 Power train ................... .9020-6 - 9020-7
P2 pressure regulator valve .......... 0360-61 Diagnosis and testing ..................... 9005-3
Speed control valve ....... 0360-70 - 0360-71 Diodes, alternator, 16 amp ..... 1672-13 - 1672-14,
Steering valve ............ 0360-67 - 0360-69 1672-17 - 1672-20,
Steering valve orifices ............ : .. 0360-64 1672-23
Transmission control valve Diodes, alternator, 42 amp ....... 1672-1 - 1672-4,
assembly ........................ 0360-67 1672-8 - 1672-10
Controls linkage, dozer. .......... .3215-l - 3215-4 Explanatory information .. : ...... 1672-l - 1672-2
Controls linkage, grou@ Removal of rear housing from
conditioning tool. .............. .4215-l - 4215-4 stator and diodes ........... .1672-3 - 1672-4
Controls linkage, parking Testing. .................. : .. 1672-8 - 1672-10
emergency brake ............. ..1115- 3 - 1115-5 Disconnect clutch, engine:
Cooling system, engine .......... .0510-l - 0510-2 Controls ...................... .0370-l - 0370-3
Components ........................... 0510-2 Elements ..................... .0370-4 - 0370-6 I
Cooling system testing ................... .9010-l, Displacement control valve,
9010-11 - 9010-12 transmission motor .......... 0360-52 - 0360-54
Theory ................................ 9010-l Components .......................... 0360-54
Cowl .................................... 1910-5 Displacement control valve,
Components ........................... 1910-5 transmission pump .......... 0360-28 - 0360-32
Components .......................... 0360-31
Double selector valve ............ .4260-l - 4260-2
Components ........................... 4260-l

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 I General Information JD750 Crawler Bulldozer
I-12 Contents and Index TM- 1136 (A pr- 79)

Dozer: Electrical system testing - Continued

Blade ....................... ..3201- 3 - 3201-5 Testing and adjustment - Continued
Components. ............... .3201-3 - 3201-4 Lighting circuit ............ 9015-31 - 9015-32
Controls linkage. .............. .3215-l - 3215-4 Starting aid. ........................ 9015-34
Components. ............... .3215-l - 3215-4 Starting circuit ............ 9015-20 - 9015-25
I Hydraulics ................... 3260-l - 3260-25 High resistance test ..... 9015-24 - 9015-25
Control valve .............. 3260-8 - 3260-15 Visual inspection ....................... 90.15-l 8
Components. ..................... .3260-8, Wire terminal location. ........ 9015-7 - 9015-13
3260-12 - 3260-14 Emergency brake, parking:
m I Cylinders. ................ 3260-16 - 3260-25 Controls linkage ............... .1115-3 - 1115-5
Components. ........... 3260-16 - 3260-24 Hydraulics .................... .1160-l - 1160-4
Pump ...................... .3260-l - 3260-5 Engine
Components. ............... .3260-l, 3260-3 Camshaft and valve actuating
Reservoir and filters ......... .3260-6 - 3260-7 means ..................... .0402-l - 0402-6
Components. ............. .3260-6 - 3260-7 Connecting rods and pistons ... .0403-l - 0403-4
Movable frame ................ .3243-l - 3243-2 Crankshaft and main bearings .. .0401-l - 0401-5
Components. ........................ 3243-l Cylinder block. ................ .0404-l - 0404-2
Sub frame .................... .3242-l - 3242-2 Cylinder head and valves ...... .0409-l - 0409-5
Components. ......................... 3242-l Engine removal and installation . .0400-3 - 0400-4
Drawbar ................................. 1511-3 Installation. .......................... 0400-4
Components ........................... 151 l-3 Removal ................... .0400-3 - 0400-4
Drive axle housing ............... .0201-3 - 0201-4 Exhaust manifold ....................... 041 O-l
Components ........................... 0201-4 Flywheel, housing and fasteners ......... 0433-l
Drive sprocket, track. .................... 0130-23 Fuel fitter. ............................. 0420-l
Components .......................... 0130-23 Fuel injection system .......... .0413-l - 0413-5
Fuel transfer pump ..................... 0421-l
E Oil cooler. ............................. 0419-l
Electrical instruments and Oiling system ................. .0407-l - 0407-3
indicators ..................... .1823-4 - 1823-6 Starting system .............. 0422-l - 0422-10
Electrical system: Thermostats, housings and
Alternator, regulator and piping ...................... .0418-l - 0418-2
charging system wiring ..... 1672-1 - 1672-24 Turbocharger ................. .0416-l - 0416-7
Batteries, supports and cables. . .1671-3 - 1671-7 Ventilating system ...................... 0408-l
Lighting system ............... .1673-l - 1673-2 Water pump ................ ...0417-1 - 0417-8
Wiring harness and switches ... .1674-l - 1674-4 Engine auxiliary systems:
Electrical system testing. ........ 9015-l - 9015-37 Cold weather starting aids. ..... .0505-3 - 0505-4
Block diagram ......................... 9015-5 Cooling system ............... .0510-l - 0510-2
Component location ........... .9015-2 - 9015-4 External fuel supply system .... .0560-l - 0560-4
Diagnosing malfunction ...... 9015-14 - 9015-16 Intake system ................. .0520-l - 0520-2
Precautions. ................ 9015-17 - 9015-18 Engine oil pressure gauge .................. 1823-3
Schematic diagram ............ 9015-6, 9015-37 Engine side shields ....................... 1910-6
Testing and adjustment ...... 9015-19 - 9015-35 Components ........................... 1910-6
Accessories ...................... ..9015-3 5 Engine speed control, external .... .1824-l - 1824-6
Air conditioning ..................... 9015-35 Components .................. .1824-l - 1824-5
Batteries ........................... 9015-l 9 Engine system testing. .......... 9010-l - 9010-15
System short test ................. 9015-19 Component location ........... .9010-2 - 9010-4
Testing voltage ................... 9015-l 9 Diagnosing malfunctions ....... .9010-5 - 9010-7
Charging circuit ........... 9015-26 - 9015-31 Testing and adjustment ...... 9010-10 - 9010-15
Instruments and indicators ........... 9015-33 Air intake system ................... 9010-15
Hour meter ....................... 9015-33 Air restriction indicator test. ........ 9010-15
indicator lights .................... 9015-33 Intake manifold pressure test. ...... 9010-15
Voltmeter ........................ 9015-33

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JD750 Crawler Bulldozer General information I
TM- 1136 (Apr- 79) Contents and Index I-13

Engine system testing - Continued Filter, engine fuel. ........................ 0420-l

Testing and adjustment - Continued Filter, engine oil .......................... 0407-3
Basic engine ....................... 9010-10 Fifter, transmission. ...................... 0360-90
Compression pressure test. ........ 901 O-10 Components .......................... 0360-90
Engine cooling system ..... 9010-l 1 - 9010-12 Final drive housing .............. .0201-3 - 0201-4
Alternator belt tension Final drive housing cover with
adjustment ..................... 9010-12 gears and shafts .............. .0250-4 - 0250-7

q
Radiator leakage. ................. 901 O-l 1 Final drive system ............... .0250-l - 0250-2
Engine lubrication system . . 9010-10 - 9010-l 1 Flywheel, housing and fasteners ........... 0433-l
Checking engine oil Components ........................... 0433-l
pressure ............. 9010-10 - 9010-11 FNR valve ................... .0360-68 - 0360-70,
Fuel system .............. 9010-12 - 9010-14 0360-81 - 0360-82
Adjusting injection pump Forward and reverse speed
cam advance ................... 9010-13 control ...................... 0315-9 - 0315-11
Fuel transfer pump pressure Components ................. 0315-9 - 0315-10
test ........................... 9010-12 Head. ....................... 0315-9 - 0315-10
Speed control adjustment .......... 9010-14 Linkage .............................. 0315-l 1
Theory of operation. .................... 9010-l Frame bottom guards ............ .1746-l _ 1746-2
Air intake system .................... 9010-l Components .................. .1746-l - 1746-2
Engine cooling system. ............... 9010-l Frame, main .................... .1741-3 - 1741-4
Engine lubrication system ............. 9010-l Frame, track ................... 0130-3 - 0130-10
Fuel system ......................... 9010-l Front crossbar ................ 0130-11 - 0130-12
Speed control linkage ................ 9010-l Components ................ 0130-l 1 - 0130-12
Visual inspection .............. .901 O-8 - 901 O-9 Front idler ...... : ............. 0130-18 - 0130-20
Air cleaner .......................... 9010-9 Components .......................... 0130-19
Fan ................................. 9010-8 Using track wear gauge. ............... 0130-18
Fan belt. ............................ 9010-8 Fuel filter, engine. ........................ 0420-l
Fuel filter. ........................... 9010-9 Components ........................... 0420-l
Fuel injection nozzles. ................ 9010-9 Fuel injection system ............ .0413-l - 0413-5
Fuel injection pump .................. 9010-8 Fuel injection nozzles. ......... .0413-4 - 0413-5
Fuel tank. ........................... 9010-8 Fuel injection pump. ........... .0413-l - 0413-3
Fuel transfer pump. .................. 9010-8 Fuel system testing ...................... .9010-l,
Hoses .............................. 9010-8 9010-12 - 9010-13
Oil and water leakage ................ 9010-8 Fuel tank and lines, engine. ...... .0560-l - 0560-4
Oil cooler ........................... 9010-8 Components .................. .0560-l - 0560-4
Radiator. ............................ 9010-8 Fuel transfer pump ....................... 0421-l
Turbocharger ........................ 9010-9 Components . : ......................... 0421-l
Engine water temperature gauge. .......... 1823-2 Fuses ................................... 1674-3
Evaporator .............................. 1830-25
Exhaust manifold, engine. ................. 0410-l G
Expansion valve ......................... 1830-26 Gauge, engine oil pressure ................ 1823-3
External engine speed control .... .1824-l - 1824-6 Gauge, engine water temperature .......... 1823-2
External exhaust systems ........ .0530-l - 0530-2 Gauge, transmission oil pressure. .......... 1823-l
External fuel supply system, Gauge, transmission oil
engine ....................... .0560-l - 0560-4 temperature. ........................... 1823-2
Components .................. .0560-l - 0560-4 Gear train backlash ....................... 0402-4
Gears, shafts, bearings, transfer
F drive..........................0851- 1 - 0851-6
Field windings .................... .0422-l, 0422-8 Components .................. .0851-l - 0851-3
Explanatory information ................. 0422-l Greases...................................I-V- 2
Repair ................................ 0422-8 Grille and grille housing .......... .1921-l - 1921-2
Components ........................... 1921-2

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 I Genbral Information JD750’ Crawler Bulldozer
I-14 Contents and Index TM- 1136 (A pr- 79)

Ground conditioning tool: Hydraulics, dozer. .............. 3260-l - 3260-25

Controls linkage. .............. .4215-l - 4215-4 Hydraulics, ground conditioning
Hydraulics .................... -4260-l - 4260-2 tool .......................... -4260-l - 4260-2
Hydraulics, parking emergency
H brake ....................... ..1160- 1 - 1160-4
Heater blowers ........................... 1830-4 Hydraulics, transmission. ........ 0360-l - 0360-90
Heater core ..................... .1830-2 - 1830-4 Hydrostatic system testing ...... 9026-2 .. 9026-138

q
Components ............................ 1830-3 Adjustment procedures. .... 9026-101 - 9026-138
Heater pipes and hoses ................... 1830-4 Component location ......... 9026-32 - 9026-34
Heater valve ............................. 1830-l Diagnosing malfunctions ..... 9026-39 - 9026-98
Heating system testing ........... .9031-l - 9031-4 Diagnostic equipment. ............... 9026-40
Hood ........................... .1910-3 - 1910-4 Diagnostic procedures ..... 9026-41 - 9026-64
Components ........................... 1910-4 Autmatic control valve
Horn .................................... 1806-3 accumulator (P9 check) 9026-63 - 9026-64
Hour meter .............................. 1823-4 Automatic control valve
Hour meter testing. ...................... 9015-33 operational check. .... 9026-59 - 9026-62
Housings and covers, transfer Engine horsepower check 9026-45 - 9026-48
drive ......................... .0841-3 - 0841-4 Transmission charge pressure
Components ........................... 0841-3 loss isolation ......... 9026-52 - 9026-53
Hydraulic oil filter light .................... 1823-5 Transmission control system
Hydraulic system (analyzer) tracking check. ....... 9026-54 - 9026-58
testing .................... .9025A-1 - 9025A-9 Transmission pressures
Components ......................... .9025A-1 test ................. 9026-50 - 9026-51
Hydraulic system pretest Transmission volumetric
check sheet ....................... .9025A-3 efficiency test ........ 9026-47 - 9026-49
Hydraulic system specifications ......... 9025A-9 Diagnostic symptoms ...... 9026-65 - 9026-98
Hydraulic system test record .......... .9025A-8 Symptoms index .................. 9026-66
Symptom index table ................. .9025A-4 General Information .......... 9026-2 - 9026-30
Tests ..................... .9025A-5 - 9025A-7 Brake valve ........................ 9026-29
Hydraulic system (flow meter) Hydrostatic transmission .... 9026-2 - 9026-16
testing ...................... 9025-l - 9025-25 Charge pump. ..................... 9026-9
Block diagram .............. 9025-12 - 9025-13 Manifold valve assembly. 9026-14 - 9026-15
Component location ........... .9025-2 - 9025-3 Motor displacement control
Diagnosing malfunctions ..... 9025-16 - 9025-18 valve .......................... 9026-l 4
Operation. .............................. 9025-9 Pump displacement control
Schematics ................ .9025-10 - 9025-11, valve ................ 9026-10 - 9026-13
9025- 14 Transmission bypass
Testing and adjustment ...... 9025-21 - 9025-25 valve ................ 9026-15 - 9026-16
Checking hydraulic pump Transmission operating
flow ................... 9025-23 - 9025-25 pressure valve ................. 9026-16
Checking hydraulic sump ............ 9025-23 Oil cooler bypass valve .............. 9026-30
Checking lift cylinder for Transmission control valve .. 9026-17 - 9026-29
leaks ............................ 9025-23 Visual inspection .... - ................. 9026-31
Checking oil lines and hoses ......... 9025-21 Hydrostatic transmission. ........ 0360-l - 0360-56
Checking system relief valve Bypass valve ............... 0360-33 - 0360-34
pressure setting .................. 9025-23 Start-up procedure ..................... 0360-4
Checking tilt or ripper Transmission motor. ......... 0360-35 - 0360-56
cylinder for leaks ................. 9025-22 Components. ............. .0360-45, 0360-54,
Lift control valve leakage 0360-56
test .............................. 9025-21 Displacement control valve. 0360-52 - 036054
Tilt control valve leakage Inspection .......................... 0360-46
test. ................... 9025-21 - 9025-22
Theory ....................... .9025-5 - 9025-6
Visual inspection ...................... 9025-20

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JD750 Crawler Bulldozer General Information I
TM- 1136 (Apr- 79) Contents and Index I-15

Hydrostatic transmission - Continued Manifold, exhaust, engine ................. 041 O-l

Transmission motor - Continued Manifold valve assembly,
Manifold valve assembly . . . 0360-55 - 0360-56 transmission ................ 0360-55 - 0360-56
Transmission pump. . . . . . . . . . . 0360-5 - 0360-32 Components .......................... 0360-56
Charge pump. . . . . . . . . . . . . 0360-26 - 0360-27 Mechanical instruments and
Components . . . . . . . . . . . . . . . 0360-l 7, 0360-31 indicators ..................... .1823-l - 1823-3
Disassembly . . . . . . . . . . . . . . . 0360-7 - 0360-17 Miscellaneous components system

q
Displacement control valve. 0360-26 - 0360-32 testing (track) ................. .9030-l - 9030-4
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . 0360-18 Adjustment ................... .9030-2 - 9030-4
Track alignment. ............ .9030-2 - 9030-4
I Track tension 1. ...................... 9030-2
Idler, front .................... 0130-18 - 0130-20 Diagnosing malfunctions ................ 9030-2
Idler, upper ................... 0130-16 - 0130-U Motor, Delco-Remy starting. ..... 0422-l - 0422-10
Indicator lights testing .................... 9015-33 Motor drive ..................... 0422-I - 0422-2,
Instrument panel ......................... 1823-l 0422-6
Instruments and indicators. ....... .1823-l - 1623-6 Explanatory information ........ .0422-l - 0422-2
Electrical ..................... .1823-4 - 1823-6 Repair ................................ 0422-6
Mechanical ................... .1823-l - 1823-3 Motor, transmission ............ 0360-35 - 0360-56
Instruments and indicators Movable frame, dozer. ........... .3243-l - 3243-2
testing ..................... 9015-32 - 9015-33
Intake system, engine. ........... .0520-l - 0520-2 N
Neutral start switch .......... . . . . . . . . . . . 1674-4 (
K Nozzle, fuel injection ......... . . . 0413-4 - 0413-5
Key switch ......... . ..................... 1823-6 Nozzle, starting aid .......... . . . . . . . . . . . 0505-4

L 0
Lift cylinder, dozer, ...................... 3260-22 Oil cooler bypass valve .................. 0360-86
Lift valve, dozer ......................... 3260-13 Components .......................... 0360-86
Light, hydraulic oil filter. ................... 1823-5 Oil cooler, engine. ........................ 0419-l
Light switch .............................. 1673-2 Components ........................... 0419-l
Light, transmission oil filter Oil cooler, transmission .................. 0360-85
indicator ............................... 1823-5 Inspection ............................ 0360-85
Lighting circuit testing .......... 9015-31 - 9015-32 Oiling system, engine ............ .0407-l - 0407-3
Lights ................................... 1673-l Oil filters and housing .................. 0407-3
Line, starting aid ......................... 0505-4 Oil pressure regulating valve ............ 0407-2
Liner, cylinder. .................. .0404-l - 0404-2 Oil pump ..................... .0407-l - 0407-2
Lubrication .......................... I-V-l - l-V-2 Components. ........................ 0407-l
Engine lubricating oils .................... l-V-2 Operator enclosure .............. .1810-l - 1810-6
Greases.................................I-V- 2 Components .................. .1810-3 - 1810-5
Hydraulic system ......................... l-V-2 Installation ............................. 181 O-6
Hydrostatic transmission .................. l-V-2 Removal ..................... .1810-l - 1810-4
Periodic service chart ..................... I-V-l Repair ....................... .1810-4 _ 1810-6
Planetary final drives and
splitter drive ........................... l-V-2 P
Storing lubricants. ........................ l-V-2 Pl over pressure relief valve . 0360-61, 0360-72
Lubrication system testing ................. 9010-l P2 pressure regulator valve . . 0360-61, 0360-72
9010-10 - 9010-11 Parking brake assembly. . . . . . 0250-8 - 0250-10
Parking emergency brake:
M Controls linkage. . . . . . . . . . . . . 1115-3 - 1115-5
Main bearings and crankshaft. .... .0401-l - 0401-5 Hydraulics . . . . . . . . . . . . . . . . ..1160-1 - 1160-4
Main frame ..................... .1741-3 - 1741-4 Components . . . . . . . . . . . . . 1160-2 - 1160-3
Components ........................... 1741-3

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 I General Information JO750 Crawler Bulldozer
l-16 Contents and Index TM-l 136 (Am-791

Periodic service chart ....................... I-V-1 Pump, fuel transfer ....................... 0421-l
Pistons and connecting rods. ..... .0403-l - 0403-4 Pump, transmission. ............ 0360-5 - 0360-32
Pivot shaft assembly ...................... 0130-7 Pump, transmission charge ..... 0360-26 - 0360-27
Planet housing with pinions and Push beam, dozer ........................ 3243-l
shafts ........................ .0250-2 - 0250-3
Port plate and cover assembly. . 0360-82 - 0360-83 R
Power train system testing ....... .9020-l - 9020-8 Radiator ........................ .0510-l - 0510-2

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Block diagram ......................... 9020-5 Components ........................... 0510-2
Component location ........... .9020-2 - 9020-4 Receiver - dryer. .............. 1830-23 - 1830-24
Diagnosing malfunctions ....... .9020-6 - 9020-7 Cross section view .................... 1830-23.
Testing and adjustments ................ 9020-8 Recoil spring and track adjuster. 0130-20 - 0130-22
Theory of operation. .................... 9020-l Rectifier assembly, alternator,
Disconnect clutch .................... 9020-l 16 amp .................... 1672-13 _ ,1672-14
Drive shafts ......................... 9020-l 1672-17 - 1672-20,
Final drive. .......................... 9020-l 1672-23
Parking brake. ....................... 9020-l Rectifier assembly, alternator,
Splitter housing ...................... 9020-l 42 amp ...................... 1672-1 - 1672-4,
Visual inspection ....................... 9020-7 1672-8 - 1672-10
Predelivery service ................ I-IV-l - I-IV-18 Refrigerant couplings .................... 1830-29
Accessible hardware torque Components .......................... 1830-29
values .............................. I-IV-18 Regulator and alternator, 16 amp 1672-13 - 1672-24
Air cleaner. ............................. I-IV-l Regulator and alternator, 42 amp 1672-1 - 1672-12
Air intake hose. ......................... I-IV-2 Regulatory controls, air
Alternator-fan-compressor belt conditioning ................. 1830-26 - 1830-28
tension. ....................... I-IV-6 - I-IV-7 Compressor relief valve ................ 1830-28
Batteries ............................... I-IV-2 Expansion valve. ...................... 1830-26
Crankcase oil level ...................... I-IV-3 Thermostatic temperature control
Engine speeds .................. I-IV-7 - I-IV-l 1 switch. ................... 1830-27 - 1830-28
Final check ............................ I-IV-18 Reservoir and filters, dozer ....... .3260-8 - 3260-7
Final drive housing oil level .............. I-IV-5 Reservoir, transmission .................. 0360-89
Front idlers, truck rollers and Return-to-neutral linkage ................. 0315-15
upper idlers .......................... I-IV-4 Components .......................... 0315-15
Fuel filter. .............................. I-IV-2 Rocker arm assembly. ........... 0402-l - 0402-4,
Fuel tank ............................... I-IV-2 0409-2
Fuel tank sump ......................... I-IV-3 Components ................... 0402-l) 0402-3,
Hydraulic oil level ....................... I-IV-6 0409-2
Hydrostatic transmission oil level. ......... I-IV-5 Rollers, track .................. 0130-13 - 0130-15
Indicator lights and gauges. ..... I-IV-13 - I-IV-14 Rotor assembly, alternator,
Light operation ......................... I-IV-14 16 amp ..................... 1672-13, 1672-18,
Lubrication. .................... I-IV-l 6 - I-IV-l 7 1672-21 - 1672-22
Neutral lock lever operation ............. I-IV-17 Rotor assembly, alternator,
Park brake ............................ I-IV-15 42 amp .............................. .1672-l,
Radiator. ............................... I-IV-3 1.672-5 - 1672-6,
Seat operation ......................... I-IV-13 1672-10 - 1672-11
Splitter gearbox oil level ................. I-IV-4 s
Steering ............................... I-IV-1 6 Safety equipment. ........................ 1806-3
Track tension adjustment. ....... I-IV-11 - I-IV-12 Safety information .................... l-II-1 - l-II-7
Transmission control. ................... I-IV-15 Seat ........................... .1821-l - 1821-7
Pressurizer blowers and switch 1830-31 - 1830-32 Components .................. .1821-l - 1821-7
Components .......................... 1830-31 Shield, brush. ............................ 191 O-7
Pump, dozer hydraulic ........... .3260-l - 3260-5 Shoe, track ................... 0130-24 - 0130-31
Pump, engine oil ................ .0407-l - 0407-2 Side shields, engine ...................... 1910-6
Pump, engine water ............. .0417-l - 0417-8
Pump, fuel injection. ............. .0413-l - 0413-3

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 JD750 Crawler B&dozer General Information I
TM- 7 136 (Apr- 79) Contents and Index l-17

Solenoid, starting aid ........... 0505-3 Specifications and torque values - Continued
Solenoid switch ................ ::&22~i; 0422-g Cylinder head and valves .... 0499-l 1 - 0499-12 .
Explanatory information ....... .. .. . .... 0422-l Dozer hydraulics .............. .3299-l - 3299-4
Repair . . . . . . . . . . . . . . . . . . . . . . .. . .. .. 0422-g Electrical system testing ...... 9035-6 - 9035-12
Special tools: Engine break-in ........................ 0499-l
Air conditioning system . . _. . . . . . .. . .. .. 1899-6 Engine cooling system .................. 0599-l
Air conditioning system testing. ... . .. 9035-21 Engine oil cooler ...................... 0499-19

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Alternator, regulator and Engine oiling system. .................. 0499-10
charging system wiring. . . . . . . . 1699-6 - 1699-7 Engine system testing ......... .9035-l - 9035-2
Batteries, supports and cables. .......... 1699-5 Air intake system .................... 9035-2
Camshaft and valve actuating Basic engine ........................ 9035-l
means ..................... 0499-26 - 0499-27 Engine cooling system. ............... 9035-l
Clutch elements ........................ 0799-2 Engine lubrication system ............. 9035-l
Connecting rods and pistons _ 0499-27 - 0499-28 Fuel system ......................... 9035-l
Crankshaft and main bearings 0499-23 - 0499-25 Speed control linkage ................ 9035-2
Cylinder block. .............. 0499-29 - 0499-31 External engine speed control ........... 1899-3
Cylinder head and valves .... 0499-31 - 0499-33 External fuel supply system ............. 0599-2 j
Dozer hydraulics ....................... 3299-5 Flywheel, housing and fasteners ........ 0499-22
Drive axle housing ..................... 0299-3 Fuel injection system ........ 0499-12 - 0499-13
Electrical system testing ............... 9035-13 Gears, shafts, bearings ........ .0899-l - 0899-2
Engine system testing ......... .9035-3 - 9035-5 General ......................... 1-111-1- l-Ill-3
Air intake system .................... 9035-5 Batteries ............................. .I-Ill-1
Basic engine ........................ 9035-3 Blade ................................. l-Ill-2
Engine cooling system. ...... .9035-4 - 9035-5 Brakes. .............................. .I-Ill-1
Engine lubrication system ............. 9035-4 Bulldozer dimensions. .................. l-Ill-3
Fuel system ......................... 9035-4 Capacities. ............................ l-Ill-2
Speed control linkage ................ 9035-5 Drawbar pull .......................... .I-Ill-1
Fuel injection system .................. 0499-34 Electrical system ....................... 1-111-1
j Gears, shafts and bearings .............. 0899-2 Engine. .............................. .I-Ill-1
Hydraulic system testing ............... 9035-l 6 Hydraulic cylinders ..................... l-Ill-2
Hydrostatic system testing. ............. 9035-l 9 Hydraulic system. ...................... l-Ill-2
I Speed controls. ........................ 0599-l Power ................................ .I-Ill-l
Starting system ....................... 0499-38 Special equipment ..................... l-Ill-2
Track systems ............... 0199-5 - 0199-10 Standard equipment. ................... l-Ill-2
Transmission hydraulics. ..... 0399-10 - 0399-14 Steering. ............................. .I-Ill-l
Turbocharger ............... 0499-35 - 0499-36 Tracks................................l-lll- 2
Water pump ........................ ..0499-3 7 Transmission ......................... .I-Ill-1
Specifications and torque values: Hydraulic system (analyzer)
Air conditioning system ........ .1899-4 - 1899-5 testing ............................. 9035-l 5
Air conditioning system testing. ......... 9035-20 Hydraulic system (flow meter)
Alternator, regulator and testing ............................. 9035-14
charging system wiring ...... .1699-l - 1699-3 Hydrostatic system testing. . _. 9035-17 - 9035-18
Axle shaft, bearings and Instruments and indicators ..... .1899-l - 1899-2
reduction gears ............. .0299-l - 0299-2 Miscellaneous components system
Batteries, supports and cables. .......... 1699-1 testing ............................. 9035-22
Camshaft and valve actuating Mounting frame ........................ 0599-2 j
means ..................... .0499-3 - 0499-7 Operator enclosure ..................... 1899-l
Clutch elements. .............. .0370-4 - 0370-6 Speed controls ......................... 0599-l 1
j Cold weather starting aid. ............... 0599-l Starting system ............. 0499-20 - 0499-22
Comfort and convenience items. ......... 1899-1 Thermostats, housings and piping. ...... 0499-18
Connecting rods and pistons ............ 0499-B Track systems ................ .0199-l - 0199-4
Crankshaft and main bearings ........... 0499-2
Cylinder block. ......................... 0499-9

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 I General Information JD750 Crawler Bulldozer
I-18 Contents and Index TM- 1136 (A pr- 79)

Specifications and torque values - Continued Switch, superheat shut-off and thermal
Track testing. ......................... 9035-22 fuse.................................. 1830-21
Transmission hydraulics. ....... .0399-l - 0399-9 Switch, thermostatic temperature
Transmission input drive shafts and control . . . . . . . . . . . . . . . . . . . . . 1830-27 - 1830-28
U-joints ............................. 0399-l System testing:
Turbocharger ......................... 0499-l 7 Electrical system . . . . . . . . . . . . . 9015-l - 9015-40
Vehicle lighting system .................. 1899-4 Engine . . . . . . . . . . . . . . . . . . . . . . 9010-l - 9010-15
Water pump .......................... 0499-18 Heating and air conditioning . . . 9031-l - 9031-20
Wiring harness and switches ............ 1699-4 Hydraulic system (flow meter) . 9025-l - 9025-25
m Speed control testing ............ 9010-1, 9010-14 Hydrostatic system . . . . . . . . . . 9026-2 - 9026-140
Speed control support. ................... 0315-13 Miscellaneous component -
,i Components .......................... 0315-13 tracks. . . . . . . . . . . . . . . . . . . . . . .9030-l - 9030-4
Speed control valve. .......... .0360-70 - 0360-71, Power train . . . . . . . . . . . . . . . . . . . .9020-l - 9020-7
0360-80 - 0360-61 Steps of diagnosis and testing. . . . . . . . . . 9005-3
Splitter housing. ................. .0841-3 - 0841-4
# 0851-l - 0851-6 T
Starter switch ............................ 1823-6 Temporary storage . ~. . . . . . . . . . . . . . . . . . . . . . I-IV-l
+tarting aid adapter, line and Testing
. nozzle. ................................ 0505-4 Air conditioning system . . . . . . . . . . . . . . . .9015-35,
Starting aid solenoid ...................... 0505-3 9031-2 - 9031-20 I
Starting aid switch ............... .0505-3 - 0505-4 Adding refrigerant-l 2 to
Starting aid testing. ...................... 9015-34 the system ............. 9031-16 - 9031-17
Starting circuit relay. ...................... 1674-4 Charging the system ...... 9031-15 - 9031-l 6
Starting circuit testing .......... 9015-20 - 9015-25 Discharging the system .............. 9031-13
Starting motor, Delco-Remy ..... 0422-l - 0422-10 Electrical testing ........... 9015-35, 9031-l 1
Starting system, engine ......... 0422-l - 0422-10 Evacuating the system. .............. 9031-13
Delco Remy starting motor .... 0422-l - 0422-10 Flushing the system ....... 9031-19 - 9031-20
Components. ........................ 0422-5 Inspecting refrigerant hoses
Explanatory information ...... .0422-l - 0422-2 and tubing ....................... 9031-20 I
Installation. ......................... 0422-l 0 Isolating compressor from
Removal ............................ 0422-2 system. .......................... 9031-l 8
Repair ..................... .0422-5 - 0422-9 Leak testing .............. 9031-19 - 9031-20
Testing and diagnosis ....... .0422-3 - 0422-4 Operational test. .................... 9031-l 1
Stator assembly, alternator, Pressure gauges .......... 9031-l 2 - 9031-l 3
16 amp .................... .1672-13, 1672-16, Safety precautions .................. 9031-l 2
1672-21 - 1672-23 Temperature pressure chart .......... 9031-l 7
Stator assembly, alternator, Afternator and regulator,
42amp .............................. .1672-l, 16 amp .................. 1672-19 - 1672-21
1672-3 - 1672-4, Alternator and regulator,
1672-8 - 1672-9 ,42 amp ................... 1672-7 - 1672-11
Steering linkage ................. .0315-4 - 0315-7 Batteries ...................... 1671-5 - 1671-6,
Components .................. .0315-5 - 0315-7 9015-19
Steering valve. ............... .0360-67 - 0360-69, High rate discharge test .............. 1671-6
0360-78 Specific gravity cell
Steering valve lever assembly ............ 0360-79 comparison test. ................... 1671-5
Steering valve orifices. .......... 036064, 0360-75 System short test ................... 9015-19
Sub frame, dozer. ............... .3242-l - 3242-2 Testing voltage ..................... 9015-l 9
Switch, battery disconnect ................. 1674-2 Compressor ................ 1830-18 - 1830-19
Switch, key .............................. 1823-6 Electrical system ............ 9015-19 - 9015-35
Switch, light. ............................. 1673-2 Accessories ........................ 9015-35
I Switch, neutral start. ...................... 1674-4 Air conditioning ..................... 9015-35
Switch, solenoid .................. .0422-l, 0422-9 Batteries ........................... 9015-19
Switch, starter. ........................... 1823-6 System short test ................. 9015-19
Switch, starting aid .............. .0505-3 - 0505-4 Testing voltage . . . . . . . . . . . . . . . . . . . 9015-19 .

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JO750 Crawler Bulldozer General Information I
TM- 1136 (Apr- 79) Contents and Index l-19

Testing - Continued Torque chart ............................. I-IV-15

Electrical system - Continued Towbar .................................. 1512-1
Charging system .......... 9015-26 - 901531 Components ............................ 1512-l
Instruments and indicators ........... 901533 Track adjuster and recoil spring. 0130-20 - 0130-22
Lighting circuit ............ 901531 - 9015-32 Components .......................... 0130-21
Starting aid ......................... 9015-34 Track chains and shoes ........ 0130-24 - 0130-31
Starting circuit ............ 9015-20 - 9015-25 Components .......................... 0130-25

q
Engine system .............. 9010-10 - 9010-15 Track frames. .................. 0130-3 - 0130-10
Air intake system ................... 9010-15 Components .......................... .0130-3,
Basic engine ....................... 901 O-l 0 0130-5 - 0130-7
Engine cooling system ..... 9010-11 - 9010-12 installation. .................. 0130-8 - 0130-10
Engine lubrication system . . 9010-10 - 9010-11 Recommended welding
Fuel system .............. 9010-12 - 9010-14 procedure ............... 0130-9 - 0130-10 .
Heating system ............... .9031-l - 9031-4 Replacing track frame wear
Hydraulic system (analyzer) . . 9025A-5 - 9025A-7 strips ............................. 0130-9
Cylinder leakage test ............... .9025A-6 Track rollers .................. 0130-13 - 0130-15
Hydraulic pump .................... .9025A-7 Checking roller wear ................... 0130-13
System relief valve test ............. .9025A-5 Components .......................... 0130-l 4 ’
Hydraulic system (flow meter) 9025-20 - 9025-24 Track systems ................. 0130-3 - 0130-31
Checking hydraulic pump Drive sprockets, chains and
flow ................... 9025-22 - 9025-24 shoes .................... 0130-23 - 0130-31
Checking hydraulic sump ............ 9025-22 Frames ...................... 0130-3 - 0130-10
Checking lift cylinder for Front crossbar .............. 0130-11 - 0130-12
leaks ............................ 9025-22 Rollers, idler and recoil spring 0130-13 - 0130-22
Checking oil lines and hoses ......... 902520 Track testing .................... .9030-l - 9030-4
Checking system relief valve Adjustment ................... .9030-2 - 9030-4
pressure setting .................. 9025-22 Track alignment. ............ .9030-2 - 9030-4
Checking tilt or ripper Track tension ........................ 9030-2
cylinder for leaks ................. 9025-21 Diagnosing malfunctions ................ 9030-l
Lift control valve leakage Transfer drive:
test. ............................. 9025-20 Gears, shafts, bearings ........ .0851-l - 0851-6
Tilt control valve leakage Housings and covers .......... .0841-3 - 0841-4
test. ................... 9025-20 - 9025-21 Transmission:
Hydrostatic system .......... 9026-2 - 9026-140 Controls ..................... 0315-3 - 0315-l 5
Adjustment procedures _. 9026-103 - 9026-140 Automatic control valve shut-
Power train ................... .9020-l - 9020-8 off valve control .................. 0315-14
Starting solenoid .............. .0422-3 - 0422-4 Automatic control valve variable
Track ........................ .9030-l - 9030-4 orifice linkage .......... 0315-l 1 - 0315-12
Turbocharger ................. .0416-l - 0416-2 Forward and reverse speed
Thermal fuse and superheat shut-off control .................. 0315-8 - 0315-l 1
switch ................................ 1830-21 Return-to-neutral linkage. ............ 0315-l 5
Thermostatic temperature control Speed control support ............... 0315-13
switch ...................... 1830-27 - 1830-28 Steering linkage ............. .0315-4 - 0315-7
Components .......................... 1830-27 Hydraulics ................... 0360-l - 0360-90
Thermostats, housings and piping . .0418-l - 0418-2 Hydrostatic transmission . _. . 0360-l - 0360-56
Components ........................... 0418-l Bypass valve ........... 0360-33 - 0360-34
Tilt cylinder dozer ............. 3260-17 - 3260-18 Transmission motor ..... 0360-35 - 0360-56
Tilt valve, dozer ......................... 3260-12 Displacement control
Timing gear train ........................ .0402-2, valve. ............. 0360-52 - 0360-54
0402-4 - Q402-5 Manifold valve
Installation and timing. ......... .0402-5 - 0402-6 assembly .......... 0360-55 - 0360-56
Camshaft gear. ............. .0402-5 - 0402-6 Transmission pump ... : .. 0360-5 - 0360-32
Injection pump gear .................. 0402-6 Charge pump ........ 0360-26 - 0360-27
Displacement control
valve .............. 0360-28 - 0360-32

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 I General lnforma tion JD750 Crawler Bulldozer
I-20 Contents and index TM- 1136 (Apr- 79)

Transmission - Continued
Hydraulics - Continued
Oil cooler . . . . . . . . . . . . . . . . . . _. . . . . . . 0360-85
Oil cooler bypass valve . . . . . . . . . . . . . . 0360-86
Transmission control valve . 0360-57 - 0360-84
Transmission filter. . . . . . . . . . .. . . . . . . . . 0360-90
Transmission operating pressure

q
valve . . . . . . . . . . . . . . . . . . 0360-87 - 0360-88
Transmission reservoir. . . . . . . . . . . . . . . 0360-89
Input drive shafts and U-joints . . .0325-l - 0325-3
Components. . . . . . . . . _. . . . ~. . . . . . . . 0325-2
Transmission oil filter indicator
light.. . . . . . . . . . . . . . . . . . . . . . . . . . . . ~. . . ~ 1823-5
Transmission oil pressure gauge . . . . . . ‘_. . . . 1823-l
Transmission oil temperature gauge . . . . . . . . 1823-2
Turbocharger. . . . . . . . . . . . . . . . . . . .0416-l - 0416-7
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . 0416-3
Testing.. . . . . . . . . . . . . . . . :~ . . . . .0416-l - 0416-2

U
Upper idlers.. . . . . . . . . . . . . . . . . 0130-16 - 0130-17
Components _~. . __. . . . . . . . . . . . . . . . __. . 0130-17

v
Valve lift check. .......................... 0402-l
Valve, oil pressure regulating .............. 0407~2
Valves and cylinder head. ........ .0409-l - 0409-5
Ventilating system, engine. ................ 0408-l
Components ........................... 0408-l
Ventilator outlet tube. ..................... 0408-l
Visual inspection:
Electrical system ...................... 9015-18
Engine ....................... .9010-8 - 9010-9
j Hydraulic system (flow meter) .......... 9025-20
Hydrostatic system .................... 9026-31
Power train ............................ 9020-7
Voltmeter ................................ 1823-4
Voltmeter testing ........................ 9015-33

W
Water pump, engine . . . . . . . .._~. 0417-l - 0417-8
Components . . . . _. . . . . . . . . . . . . . . 0417-l
Window wipers . . . . _. . . . . . 1810-3 - 1810-4,
1810-6
Components . . . . . ~ . . . . . . . . . . . 1810-3 - 1810-4
Windshield washer. . . . . . . . . . . . . . . 1810-3, 1810-5
Wiring harness . . . . . . . . . . . . . . . . . . . . . . . . . 1674- 1

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JD750 Crawler Bulldozer General Information I
TM- 1136 (Feb- 77) introduction and Safety information 11-l

Group II
INTRODUCTION AND SAFETY INFORMATION
INTRODUCTION

Use FOS Manuals for Reference Use Technical Manuals for Actual Service

This technical manual is part of a twin concept of This technical manual was planned and written for
service: you-an experienced service technician. Keep it in a
The two kinds of manuals work as a team to give you permanent binder in the shop where it is handy. Refer
both the general background and technical details of to it whenever in doubt about correct service proce-
shop service. dures or specifications.

lFOS Manuals-for reference Some features of this manual:

Fundamentals of Service (FOS) Manuals cover

l Inside front cover - “Table of Contents”.
basic theory of operation, fundamentals of trouble
shooting, genera/ maintenance, and basic types of
0 Section 1 - Contents, safety information,
failures and their causes. FOS Manuals are for training
general specifications and general services.
new personnel and for reference by experienced ser-
vice technicians.
o Sections 1 through 42 - Removal, repair,
When a service technician should refer to a testing (components removed), installation,
m FOS Manual for more information, a FOS and adjustment.
symbol like the one at the left is used in the
0 Q TM to identify the reference. l Section 90 - Detailed explanation of system
operation, diagnosis, visual inspection, testing,
lTechnical Manuals-for actual service and adjustments.

Technical Manuals are concise service guides for a

l Specifications grouped and illustrated at the
specific machine. Technical manuals are on-the-job
end of each section.
guides containing only the vital information needed by
an experienced service technician.

Litho in U.S.A.
I General Information JD 750 Crawler Bulldozer
H-2 Introduction and Safety Information TM- 1136 (Feb-77)

MAINTENANCE WITHOUT ACCIDENT

WORK SAFELY
RIGHT,;;&:

T'27999N

A This safety alert symbol is used for important

safety messages. When you see this symbol,
the possibility of personal injury exists if safety mes-
sage is not followed.
T27502N

EVERY EMPLOYER HAS A ALWAYS AVOID loose clothing or any accesso-

SAFETY PROGRAM. KNOW ry-flopping cuffs, dangling neckties and scarves, or
WHAT IT IS! rings and wrist watches-that can catch in moving
parts and put you out of work.

T43.566

BE ALERT!
Plan ahead - work safely -
avoid accidental damage and
injury. If a careless moment does
cause an accident or fire, react
Consult your shop supervisor for specific instruc- quickly with the tools and skills at
tions on a job, and the safety equipment required. hand - know how to use a first
aid kit and a fire extinguisher -
For instance, you may need: Hard hat, safety shoes, and where to get aid and assis-
safety goggles, heavy gloves, reflector vests, ear pro- tance. In an emergency, split-
tectors, respirators. second action is the key to safe-
ty.

Litho in U.S.A.
JD 750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Feb-77) Introduction and Safetv Information II-3

MAINTENANCE WITHOUT ACCIDENT

Specific safety procedures should always be ob- Never use an open flame as a light anywhere on or
served, whether servicing or making repairs on the around the equipment.
crawler. Remembering these-in time!-can prevent KNOW WHERE FIRE EXTINGUISHERS ARE KEPT!
an injury.. .or save your life.. . .
UNDER ALL MAINTENANCE
AVOID FIRE HAZARDS- CONDITIONS-
Fuel Is Dangerous! Do not perform any work on the crawler unless
authorized to do so. Then be sure you understand the
Don’t smoke while refueling.
services required. Follow recommended procedures.
Don’t smoke while handling highly flammable mate-
rial.
Never service the equipment while it is being
Engine should be shut off when refueling.
operated.
Use care in refueling if the engine is hot.

Don’t use open pans of gasoline or diesel fuel for

Avoid working on equipment with the engine run-
cleaning parts. Good commercial, nonflammable sol-
ning. If it is necessary to make checks with the engine
vents are preferred.
running, ALWAYS USE TWO SERVICE TECHNI-
CIANS-one, the operator, at the controls, the other
Battery Gas Is Highly Flammable!
checking in view of the operator. Also, put the trans-
Provide adequate ventilation when charging batter- mission in neutral, set the parking brake, and apply any
ies. safety locks provided. KEEP HANDS AWAY FROM
MOVING PARTS.

5275061

Don’t check battery charge by placing metal objects

across the posts.
Don’t allow sparks or open flame near batteries.
Don’t smoke near battery.

Flame Is Not a Flashlight!

Never check fuel, battery electrolyte or coolant
levels with an open flame.
Never use an open flame to look for leaks anywhere
on the equipment.

Litho in U.S.A.
 I General Information JD 750 Crawler Bulldozer
II-4 Introduction and Safety Information TM- 1136 (Feb-77)

MAINTENANCE WITHOUT ACCIDENT

Before servicing, adjusting, or repairing crawlers Make sure the maintenance area is adequately
which have attachments such as blades, etc.- vented.
LOWER attachments to the ground-or, if necessary
to raise them for access to certain parts, SECURELY Keep maintenance area CLEAN AND DRY. Oily and
SUPPORT by external means. DO NOT rely on con- wet floors are slippery; greasy rags are a fire hazard;
trols to support or position attachments for mainte- wet spots are dangerous when working with electrical
nance. equipment.
m
Never allow ANYONE to walk under equipment that Store starting aids in a cool and well-ventilated
is raised and not properly blocked. place, out of the reach of unauthorized personnel.

SERVICING PRECAUTIONS
Stop the engine before cleaning or lubricating the
crawler.

Lower blade and ripper to the ground carefuly.

,, ,”
,:: ,,
*’ ,,

i-43669 \

Avoid working directly under raised and blocked

equipment unless absolutely necessary.

If the crawler is on an incline, block it securely.

Use hoisting equipment for lifting heavy parts. TAKE

T4.7671
CARE! WATCH OUT FOR OTHER PEOPLE IN THE
VICINITY.
Engine coolant gets hot! Don’t remove the radiator
cap until coolant temperature is below the boiling point.
Use extreme caution in removing radiator caps,
Then turn cap slightly to relieve pressure before re-
drain plugs, grease fittings, or hydraulic pressure caps.
moving.

Exhaust gases are dangerous! Periodically check

exhaust system for excessive leakage.

Don’t forget a hydraulic system may be pressurized!

To relieve system pressure, stop engine, lower blade
and ripper and operate blade and ripper control levers
until system fails to respond.

When checking hydraulic pressure, be sure to use

the correct test gauge for the pressure in the particular
system.
Wear safety glasses when drilling, grinding, or
hammering metal.

Litho in U.S.A.
1 JD750 Crawler Bulldozer General lnforma tion I
~ TM-1 136 (Feb-77) Introduction and Safety Information II-5

MAINTENANCE WITHOUT ACCIDENT

m
T43672

Keep ALL components free of dirt and oil. This Before removing any housing covers, stop engine.
attention will minimize fire hazards and facilitate spot- Take all objects from your pockets which could fall into
ting of loose or defective parts. the opened housings. Don’t let adjusting wrenches fall
into opened housings.
When preparing engine for storage, remember that
inhibitor is volatile and therefore dangerous. Seal and . ~. for Maintenance Adjustments
tape openings after adding the inhibitor. Keep con-
tainer tightly closed when not in use. Don’t attempt to check belt tension while the engine
is running.
ADJUSTING PRECAUTIONS
. . for Operating Adjustments

Before making adjustments, stop engine.

Don’t adjust the fuel system while the machine is in

motion.

T43673

Always wear gloves when handling cable.

Lifho in U.S.A.
 ,y
I General Information JD750 Crawler Bulldozer
II-6 Introduction and Safety Information TM- 1136 (Feb-77). %

MAINTENANCE WITHOUT ACCIDENT

PRECAUTIONS DURING Stop the engine and securely block the blade.
REPAIR
Before working on the engine fuel system-close
fuel shutoff valve.

Never let your bare hands come in contact with

T43576 sharp edges. WEAR GLOVES.
Before repairing the electrical system, or performing
a major overhaul, make sure the batteries are discon-
netted.

Litho in U.S.A.
, JD750 Crawler Bulldozer General Information
TM- 1136 (Feb-77) Introduction and Safety Information

MAINTENANCE WITHOUT ACCIDENT .ii.,

?i
t

KNOW EQUIPMENT IS READY!

Check guards, ROPS, safety bars-ail protective
devices installed on the crawler. Every one should be
in place and secure.

CHECK IT OUT!

0 GUARDS
0 SHIELDS
0 PROTECTIVE DEVICES
0 ROLL-OVER PROTECTIVE STRUCTURES
Cl SEAT BELTS
0 FIRE EXTINGUISHER, ETC. T4.7660

Be sure to clean any oil, grease or mud accumula-

tion from floor of operator’s compartment, stepping
points, and grab rails to minimize the danger of slip-
,?
ping.

In freezing weather beware of snow or ice deposits

on stepping points, grab rails, and floor.
1..

Remove loose bolts, tools, or other objects from

floor of operator’s compartment. -
T453678
Although it is impractical to try to cover every possi-
Carefully inspect equipment for visual defects- ble maintenance situation, the safety precautions rec-
leaks in fuel, lubrication, and hydraulic systems. Do not ommended here should serve to develop and promote
search for pressurized fluid leaks with your hands. Use safe maintenance procedures.
cardboard or wood to search for leaks.
The information contained in this manual is not
intended to replace safety codes, insurance require-
ments, federal, state, and local laws, rules and regula-
tions. In particular, your service area or jobsite activi-
ties may be subject to state safety rules and/or federal
regulation under the Occupational Safety and Health
Act (OSHA). Familiarize yourself with all regulations
applicable to your situation in order to avoid possible
safety violations.

Illustrations and copy reproduced in part by permis-

sion of Construction Industry Manufacturers’ Associa-
T&3679
tion (CIMA).
Check levels of fuel, coolant, hydraulic fluid, and
lubricating oil. If fuel must be added-FIRST, PUT
OUT THAT CIGARET.

Check and secure all caps and filler plugs for fuel,
oils, radiator, etc.

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozer
II-8 Introduction and Safety lnforma tion TM- 1136 (Mar-84)

Prevent Fires Before Starting Engine

Check the fire extinguisher for correct charge.

Open both side shields and grille and remove trash.

Remove trash from bottom guards, drive lines, bat-

teries, hydraulic lines, fuel tank and operator’s station.

Check for leaking fuel lines, hydraulic lines, hoses, or

fittings with a piece of cardboard or wood. Do not use
your hands. Tighten loose fittings. If lines are bent or
hoses kinked, install new parts.

Escaping fluid under pressure can penetrate the skin

Prevent Fires After Stopping Engine
causing serious injury. Relieve pressure before discon-
necting hydraulic or other lines. Tighten all connections Temperature in engine compartment may go up im-
before applying pressure. Keep hands and body away mediately after you stop the engine. BE ON GUARD
from pinholes and nozzles which eject fluids under high FOR FIRES.
pressure. Use a piece of cardboard or paper to search
for leaks. Do not use your hand. Before you clean trash from the engine compartment,
wait until the engine has cooled. Open side shields to
If ANY fluid is injected into the skin, it must be surgi- cool the engine faster. While the engine cools, clean
cally removed within a few hours by a doctor familiar trash from other areas.
with this type injury or gangrene may result.
Avoid possible injury or death from machinery
High pressure may be present in track cylinder. If runaway.
grease does not immediately escape from vent hole,
drive crawler forward and backward slowly, then tighten Do not start engine by shorting across starter termi-
check valve. nals. Machine will start in gear and will move if normal
circuitry is bypassed.
Use extreme care when servicing area of track ad-
juster and recoil spring. Do not attempt to disassemble NEVER start engine while standing on ground. Start
without proper tools and knowledge of disassembly engine only from operator’s seat, with transmission in
procedure. neutral, reverser in neutral, and park brake applied.

If ROLL-GARD@ protective frame or ROLL-OVER

protective equipment is loosened or removed for any
reason, make certain all parts are reinstalled correctly.
Tighten mounting bolts to proper torque. The protection
offered by ROPS will be impaired if the ROPS is subject
to structural damage, has been involved in an overturn
incident or is in anyway altered. Damaged ROPS should
be replaced, not reused.

Use a heavy-duty grounded cord to connect coolant

heater to electrical power.

Do not plug into electrical power unless heating ele-

ment is immersed in coolant. Sheath could burst and
result in personal injury.

Litho in U.S.A.
 JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) General Specifications 111-l

Group III
GENERAL SPECIFICATIONS
Specifications and design subject to change without notice. Wherever applicable, specifications are in accordance
with ICED and SA E Standards. Except where o then&e no ted, these specifications are based on a unit equipped with
roll-over pro tee tive canopy, 18 in. (457 mm) grousers, full fuel tank, 775 lb (79 kg) opera tot-, and standard equipment.

Power (@ 2100 rpm): SAE Transmission:

Gross.. . . . . . . . . . . .122 hp (91 kW*)
Net.. . . . . . . . . . . . . . 110 hp (82 kW*) 111.5 PS Cold weather starting. . . . Disconnect clutch complete-
ly disengages splitter drive, hydrostatic drive and all
Net engine flywheel power is for an engine equipped hydraulics.
with fan, air cleaner, water pump, lubricating oil pump, Splitter drive. . . . Pressure-lubricated helical gears
fuel pump, alternator and muffler. The ,gross engine drive both hydrostatic transmissions, main hydraulic
power is without fan. Flywheel power ratings are under pump, winch drive shaft and auxiliary pump drive.
SAE standard conditions of 500 ft. (150 m) altitude and
1 85’F (29%) temperature, and DIN 6270 conditions Drive. . . . Dual-path, fully automatic, infinitely variable
(non-corrected). No derating is required up to 10,000 hydrostatic transmissions.
feet (3 000 m) altitude.
’ In the international System of units (SI), power is ex- Speeds. . . . Infinite from 0 to 6.5 mph (0 to 10.5 km/h)
pressed in kilowatts (kW). forward or reverse.

Engine: Control. . . . Single, lever, variable speed, forward and

John Deere 6-cylinder turbocharged diesel, valve-in- reverse.
head, 4-stroke cycle.
Steering:
Bore and stroke. . . . . . . . , . . . . . . . . . . . . 4.19x5 in. Fully modulated, infinitely variable lever steering for
(106.4~127 mm) live power turns and counter-rotation. Pedal steering
Piston displacement. . . . . . . . . . . . . . . . . . 414 cu. in. optional. No need for steering clutches or steering
(6 784 cm3) brakes.
Compression ratio . . . . . . . . . . . . . . . . . . . 16.2 to 1
Maximum torque @ 1300 rpm . . . . . . . . . . .345 lb-ft Brakes:
(468 N-m) (48 kg/m)
Service. . . . . . . . . . . . . . . . . . . . . . . . . . . Hydrostatic
NACC or AMA (U.S. Tax) horsepower . . . . . . . _ . 42
Lubrication . . . . . . . . . . . . . . . . . . . . Pressure system
with full flow filters Parking. . . . Wet-disk brakes are automatically applied
when engine is stopped, or manually applied with center
Main bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
foot pedal during normal operation.
Cooling. . . . . . . . . . . . . Pressurized with thermostat
and controlled bypass
Drawbar pull:
Fan..................................Blower
Air cleaner with restriction indicator . . . . . . . . . . Dry, Maximum drawbar pull . . . . . . . . . . . . . . 47,500 lb.
dual stage (213 kN) (21 550 kg)
Electrical system . . . . . . . . . . . 24 volt with alternator at 0.30 mph
Batteries, two-l 2 volt . . . . . . . . . . Reserve capacity: (0.48 km/h)
180 minutes each
Usable pull will depend on traction and weight of the
tractor.

Litho in U.S.A.
 I General lnforma tion JD750 Crawler Bulldozer
111-2 General Specifications TM- 7 136 (Mar-84)

750 GENERAL-PURPOSE CRAWLER 750/6505 ALL-HYDRAULIC DOZER

Hydraulic System: Open-center (optional) Hydraulic System: Open-center
Control . . . . . . . . . . . . Single-lever, two-function control Control. .................... Two-lever, three function control
Pump . . . . . . Vane, 38 gpm (2.40 Us) @ rated engine speed Pump .......... Vane, 38 gpm (2.40 Us) @ rated engine speed
Pressure. . . .. . . . 2000 psi (13 790 kPa) (140.6 kg/cm’) Pressure. ........... I ... 2000 psi (13 790 kPa) (140.6 kg/cmz)
Tracks: 6-roller track frame w/front guides. DURA-TRAXTM deep- Hydraulic Cylinders: Bore Stroke
heat-treated sealed track links and through-hardened sealed rollers Angie, two ............ 6.25in.(159mm) 15.37 in. (390 mm)
provide maximum wear resistance. Lift, two .............. 4,25in.(108mm) 26.50 in. (673 mm)
Grouser . . . . . . ., ....... . .... . . . 18 in. (457 mm) Tilt, one .............. 6.25 in. (159 mm) 4.51 in. (115 mm)
Track shoes, each side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Cylinder rods ..... Ground, heat-treated, chrome-plated, polished
Grounded contact area . . . . .. . . .3240 sq. in. (20 903 cm2) Cylinder pivot pins ........ Hardened steel (replaceable bushings)
Ground pressure . . .. . .7.71 psi (53.2 kPa) (0.542 kg/cm’)
Length of track on around . . . ..... . . 90 in. (2.29 m) Tracks: 6-roller track frame w/front and rear track guides and sprock-
Track gauge. .... .-. ........... . . . . . . . . . . . 74.in. (1188 mmj et guard. DURA-TRAXTM deep-heat-treated sealed track links and
Oscillation ................... . . . . . . . . . . . 10 in. (254 mm) through-hardened sealed rollers provide maximum wear resistance.
Carrier rollers ................. . . . . . . . . . . . . . . . 2 each side Grouser ................................. 18 in. (457 mm)
Adjustment. .................. . . . . . . . . . . . . . . . . . Hydraulic Track shoes, each side ................................ 40
Minimum ground clearance ...... . . . . . . . . . . . 14 in. (356 mm) Ground contact area ............... .3240 sq. in. (20 903 cm2)
Ground pressure ........... .9.66 psi (66.6 kPa) (0.679 kg/cm2)
Capacities: U.S. Liters Length of track on ground ................... 90 in. (2.29 m)
Coaling system ............... . . . ,. . 1 7 gal. 26.5 Trackgauge.. ....... . ...................... 74in.(1.88m)
Fuel tank .................... .. 73 gal. 276.3 Oscillation ............................... 10 in. (254 mm)
Crankcase ................... . . 18 qt. 17.0 Carrier rollers, ............................... .2 each side
Crankcase, includino filter ....... . . . . . . 20 qt. 18.9 Adjustment ...................................... Hydraulic
Splitter drive .... .-. ....................... 1.5 gal. 5.7 Minimum ground clearance .................. 14 in. (356 mm)
Final drive, each: 1st reduction. .............. 8.5 aal. 32.2
2nd reduction ........ 3.5 ial. 13.2 Blade:
Hydraulic system (optional) ............ 33 gal. 124.9 Cutting edge .................................... d-piece
Hydrostatic drives ................... 33 gal. 124.9 Center section ............................ 0.75 in. (19 mm)
End bits, boron steel.. . . . . . . . . . . .. 0.75 in. (19 mmj
SAE Operating Weight w/ROPS ........ 24,980 lb. (11 330 kg)
Capacities: U.S. Liters
Cooling system . . . . . . . . . . 7 gal. 26.5
750/6525 BULLDOZER SPECIFICATIONS Fuel tank . . . . . . . . . . . . . . . . . . . 73 gal. 276.3
Hydraulic System: Open-center Crankcase . . . . . . . . . . . . . . . . . .. 18 qt. 17.0
Control . ... ..... . .. Single-lever, two function control Crankcase, including filter . . . . . . 20 qt. 18.9
Pump . .. . Vane, 38 gpm (2.40 L/s) @ rated engine speed Splitter drive ... .. . . . . 1.5 gal. 5.7
Pressure. . . . . . . . . 2000 psi (13 790 kPa) (140.6 kg/cmz) Final drive, each: 1st reduction. .. 8.5 gal. 32.2
2nd reduction . 3.5 gal. 13.2
Hydraulic Cylinders: BOW3 Stroke Hydraulic system . . . . . . . . . . 33 gal. 124.9
Lift, two ....... 4.25 in. (108 mm) 31.85 in. (809 mm) Hydrostatic drives .. ...... . . 33 gal. 124.9
Tilt, one . . . . ... 5.5 in. (140 mm) 5.71 in. (145 mm)
Cylinder rods . . . . Ground, heat-treated, chrome-plated, polished SAE Operating Weight w/ROPS . . . ~ . . 31,300 lb. (14 200 kg)

Tracks: B-roller track frame w/front and rear track guides and sprock-
et guard. DURA-TRAXTM deep-heat-treated sealed track links and
750/6520 ANGLEDOZER
through-hardened sealed rollers provide maximum wear resistance. Hydraulic System: Open-center
Grouser . . . . . .. .. . . . . . . . . . . . . 18 in. (457 mm) Control . ..... . . . . . . . . . . Singlelever, two function control
Track shoes, each side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Pump . . . ,~,. Vane, 38 gpm (2.40 Us) @ rated engine speed
Ground contact area . . . .3240 sq. in. (20 903 cm2) Pressure. . . . . . ,. . . . . . . . 2000 psi (13 790 kPa) (140.6 kg/cmz)
Ground pressure . . . . . 8.95 bi (61.7 kPa) (0.629 kg/cm”)
Length of track on ground . . . . . . . . . . . . . . . 90 in. (2.29 m) Hvdraulic Cvlinders: Bore Stroke
Track gauge. . . . . . . . . . . . . . . . . . . . . . . . 74 in. 0.88 m) Lift, two . . .-. . . . . . . . 4.25 in. (108 mm) 32.05 in. (813 mm)
Oscillation . . . . .. : 10 in. (i54 mmj Tilt. two . . . . . 5.5 in. (140 mm) 4.33 in. (110 mm)
Carrier rollers . . . . . . . . . . . . . 2 each side Cylinder rods . . . Ground, heat-treated, chrome-plated, polished
Adjustment. . .... .. . . . . . . Hydraulic Tracks: g-roller track frame w/front and rear track guides and sprock-
Minimum ground clearance .. . . 14 in. (356 mm) et guard. DURA-TRAXTM deep-heat-treated sealed track links and
Blade: through-hardened sealed rollers provide maximum wear resistance.
Cutting edge .. ..... ... .... .. .. ...... . 3-piece Grouser . ._ ... ... .. . . . . . . . 18 in. (457 mm)
Center section . . . . . . . . . . . . .. . . . . . 0.75 in. (19 mm) Track shoes, each side . . . . . . . . . . . . 40
End bits, boron steel.. ..... .. ... . . . . . 0.75 in. (19 mm) Ground contact area . . . . . . . .3240 sq. in. (20 903 Cm2)
Ground pressure ... . . .9.05 psi (62.4 kPa) (0.668 kg/cm”)
Zapacities: U.S. Liters Length df track on ground ....... .: .. 1. ...... 90 in. (2.29 m)
Zooling system .. . . . . 7 gal. 26.5 Trackaauae ............................... 74in.(1.88m)
%el tank . .. . ... ... . 73 gal. 276.3 Oscillaiion-. .............................. 10 in. (254 mmj
Crankcase . . . . .. 18 qt. 17.0 Carrier rollers. sealed. .......................... 2 each side
Crankcase, including filter . . . . 20 qt. 18.9 Adjustment. .................................... Hydraulic
Splitter drive . . . . . . . 1.5 gal. 5.7 Minimum ground clearance .................. 14 in. (356 mm)
-inal drive, each: 1st reduction. . 8.5 gal. 32.2
2nd reduction . 3.5 gal. 13.2 Blade:
iydraulic system (optional) . . . 33 gal. 124.9 Cutting edge .................................... 3-piece
iydrostatic drives . . .. . . 33 gal. 124.9 Center section ............................ 0.75 in. (19 mm)
End bits, boron steel ....................... 0.75 in. (19 mm)
SAE Operating Weight w/ROPS ..... . 29,055 lb. (13 180 kg)
Continued on next page

Litho in U.S.A.
 JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) General Specifications Ill-3

Capacities: U.S. Liters Length of track on ground 90 in. (2.29 m)

Co&ing system . .. . . .. 7 gal. 26.5 Trackgauge............ 64 in. (1.63 m)
Fuel tank . . . . . . . . . . . ..__... . . 73 gal. 276.3 Oscillation . ... ..... ‘10 in. (254 mm)
Crankcase . . . . . . . . . . . . . . . . . .. .. 16 qt. 17.0 Carrier rollers, sealed. . . . . . . 2 each side
Crankcase, including filter . . .. .. 20 qt. 16.9 Adjustment. . . . . . . . . . . . . . . . . Hydraulic
Splitter drive . . .... .. . 1.5 gal. Minimum ground clearance 14 in. (356 mm)
Final drive. each: 1 st reduction. .. .. 6.5 ial. 355
2nd reduction .. .. 3.5 gal. 13:2 Blade:
Hydraulic system . .... . ~ 33 gal. 124.9 Cutting edge . .. ... .. . .. . . . . . . . . . . . 3-piece
Hydrostatic drives .... .. .. 33 gal. 124.9 Center section . . . . . . . . ... .. . . . 0.75 in. (19 mm)
End bits, boron steel . . ... . . . . 0.75 in. (19 mm)
SAE Operating Weight w/ROPS .. . 29,390 lb. (13 330 kg)
Width over standard end bits . . 96.62 in. (2.50 mm)
Width without end bits . ... . . . 95.9 in. (2.44 mm)
750 WIDE-TRACK BULLDOZER
Capacities: U.S. Liters
Hydraulic System: Open-center
Cooling system .............. 7 gal. 26.5
Control ..................... Single-lever, two-function control
Pump .......... Vane, 36 gpm (2.40 Us) @ rated engine speed Fuel tank ................... 73 gal. 276.3
Pressure ................ 2000 psi (13 790 kPa) (140.6 kg/cm*) Crankcase .................. 16 qt. 17.0
Crankcase, including filter ...... 20 qt. 16.9
Hydraulic Cylinders: Bore Stroke Splitter drive ................ 1.5 gal. 5.7
Lift, two .............. 4.25in.(lOSmm) 31.65 in. (609 mm)
Final drive, each: 1 st reduction. . 5.375 gal. 20.3
Tilt, one .............. 5.5 in. (140 mm) 5.71 in. (145 mm)
2nd reduction . 3.5 gal. 13.2
Cylinder rods ..... Ground, heat-treated, chrome-plated, polished
Cylinder pivot pins ........ Hardened steel (replaceable bushings) Hydraulic system ............. 33 gal. 124.9
Hydrostatic drives ............ 33 gal. 124.9
Tracks: 6-roller track frame w/front and rear track guides and sprock-
et guard. DURA-TRAXTM deep-heat-treated sealed track links and SAE Operating Weight w/ROPS ........ 29,239 lb. (13 260 kg)
through-hardened sealed rollers provide maximum wear resistance.
Grouser ................................. 34in.(664 mm) 750 LOW GROUND PRESSURE BULLDOZER
Track shoes, each side.. .............................. 40
Ground contact area ............... .6120 sq. in. (39 464 cm*) Hydraulic System: Open-center
Ground pressure ............ .5.1 psi (35.2 kPa) (0.356 kg/cm*) Control . . .... .. . . . . . . . . . . . . Single-lever, two function control
Length of track on ground ................... 90 in. (2.29 m) Pump . . . ...,. Vane, 36 gpm (2.40 Us) @ rated engine speed
Track gauge ............................... 74 in. (1.66 m) Pressure. ....... . . . . . . . . 2000 psi (13 790 kPa) (140.6 kg/cm*)
Oscillation ............................... 10 in. (254 mm)
Carrier rollers. ............................... .2 each side Hydraulic Cylinders: Bore Stroke
Adjustment. .................................... Hydraulic Lift. two . . . . . . . . . . . . . . 4.25 in. (106 mm) 40.16 in. (1020 mm)
Minimum ground clearance .................. 14 in. (356 mm) Tilt, one . . . . . . . . . . . 5.25 in. (140 mm) 5.71 in. (145 mm)
Cylinder rods . . . . . Ground, heat-treated, chrome-plated, polished
Blade:
Cutting edge .................................... 3-piece Tracks: 7-roller track frame w/front, center and rear track guides and
Center section ........................... .0.75 in. (19 mm) sprocket guard. DURA-TRAXTM sealed chain, deep-hardened track
End bits, boron steel ....................... 0.75 in. (19 mm) links and &lers provide maximum wear resistan&
Shoewidth............................... 34in.(665mm)
Capacities: U.S. Liters Grouser height (single grouser shoe) . 2.17 in.’ (55 mmj
Cooling system ........................... 7 gal. 26.5 Track shoes. each side . . . . . . . 46
Fuel tank ................................ 73 gal. 276.3 Ground contact area . . . . . . . . . .7546 .sd.‘in: $4 69i’ crn2)
Crankcase ............................... 16q t. 17.0 Ground pressure . . . . . . . . . . . : 4.5 psi (31 kPa) (0.316 kg/cm*)
Crankcase, including filter ................... 20 qt. 16.9 Length of track on ground . . . . . . . . . . . . . . . . . 111 in. (2.62 m)
Splitter drive .... .-. ....................... 1.5 gal. Track gauge. .... .-. ........................ 74 in. (1.66 m)
Final drive. each: 1st reduction. .............. 6.5 aal. Oscillation ............................... 15 in. (361 mm)
2nd reduction .......... ... 4.5 ial. 17.0 Carrier rollers (each side). . . . . . . . . ............ 2
Hydraulic system ......................... 33 gal. 124.9 Adjustment. . . . . . . . . . . ... . ...... Hydraulic
Hydrostatic drives ........................ 33 gal. 124.9 Minimum ground clearance
With single-bar grouser (excluding
SAE Operating Weight w/ROPS ........ 31.375 lb. (14 230 kg) grouser height). . . . . . . . . . . . 14 in. (356 mm)
With swamp shoe (including
750 NARROW-GAUGE BULLDOZER grouser height). . . . . . . . . . . . 17.2 in. (437 mm)

Hydraulic System: Open-center Cutting Edge:

Control . . . . . . . . . . . . . Single-lever, two function control Center section, heat-treated boron
Pump .. Vane, 36 gpm (2.40 Us) @ rated engine speed steel, reversible . . . . . . . . . . . . . . ........ 0.75 in. (19 mm)
Pressure.. . . .. . . 2000 psi (13 790 kPa) (140.6 kg/cm*) End bits, boron steel . . . . . . . . . . . . ........ 0.75 in. (19 mm)

Hydraulic Cylinders: Bore Stroke CaDacities: U.S. Liters

Lift, two.. . . . . . . 4.25in.(106mm) 31.65 in. (609 mm) Co&ing system ........................... 7 gal. 26.5
Tilt, one .. .. 5.5 in. (140 mm) 5.71 in. (145 mm) Fuel tank ................................ 73 qal. 276.3
Cylinder rods . Ground, heat-treated, chrome-plated, polished Crankcase . . . . . . . . . . . . . . . . . ... ... 16qt. 17.0
Crankcase, including filter . . . ... ... 20 qt. 16.9
Tracks: 6-roller track frame w/front and rear track guides and sprcck- Splitter drive . . . . . . . . . . . . . ... ... 1.5 gal. 5.7
et guard. DURA-TRAXTM deep-heat-treated sealed track links and . Final drive, e&& 1st reduction ............... 6.5 ial. 32.2
through-hardened sealed rollers provide maximum wear resistance. I’ ::2nd reduction .............. 4.5 gal. 17.0
Grouser . . . ...... . . . . . . . . . . . . 16 in. (457 mm) Hydraulic sysie*m . . . . . . . . . . . . . ... ... 33 Gal. 124.9
Track shoes, each side . . . . . . . . . . . . . . .._............ . . . 40 Hydrostatic drive . . . . . . . . . . . . ...... 33 gal. 124.9
Ground contact area . . . . . . . . . . . .3240 sq. in. (20 903 cm*)
Ground pressure . . . . . .9.02 psi (62.2 kPa) (0.634 kg/cm*) SAE Operating Weight w/ROPS . . . 34,000 lb. (15 422 kg)
..

Litho in U.S.A.
I General lnforma tion JD 750 Crawler Bulldozer
Ill-4 General Specifications TM-7 736 (Mar-84)

GENERAL-PURPOSE CRAWLER DIMENSIONS

b-1 1 ft. 10 in. (3.61 m)--4

w/18 in. (457 mm) shoes

bitho in U.S.A.
JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) General Specifications III-5

6525 BULLDOZER DIMENSIONS

I- 16 ft. 5.3 in. (6.01 m)

Limb risers and brush-protection assembly for roll-over
protective structure

Litho in U.S.A.
I General lnforma tion JD.750 Crawler Bulldozer
III-6 General Sioecifica tions TM- 1136 (Mar-84)

6505 ALL-HYDRAULIC DOZER DIMENSIONS

-

=lOR.
(3.1

36 in.
(914 mm)

ID n. L.3 I”. -: ._
- lLtMm\ *. ‘\ 4 (483 mm)

17ft.2in.(5.23m)-/
Limb risers and brush-protection assembly for roil-over
protective structure

Litho in U.S.A.
 JD 750 Crawler Bulldozer General Information
TM- 1136 (Mar-84) General Specifications

6520 ANGLEDOZER DIMENSIONS

t- - -

10 ft. 2.6 in.

(3.11 m)

t
34.5 in.
n (675 mm)
3
I

I 4
2d in.
1_ 1yg.;l”. (506 mm)
I

I
: 12.75 in.
1 (324 mm)

16lt. 9.3in. (5.11 m) -1

Limb risers and brush-protection assembly for roll-over
protective structure

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozer
III-8 General Specifications TM- 1136 (Mar-84)

750 WIDE-TRACK BULLDOZER DIMENSIONS

--T--f!- rl

(914mm)

15ft. 5.6 in

15 in.
(361 mm)

t-16ft. 5.3 in. (5.01 m)-1

Limb risers and brush-protection assembly for roll-over

protective structure

Litho in U.S.A.
JD 750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) General Specifications III-9

750 NARROW-GAUGE BULLDOZER DIMENSIONS

---F-n n

IO ft. 2.6 in.

(3.11 m)

+ #
---_
--N_
15ft.5.6in. 20 in.
’ (4.70 m) (508 mm)
.

16 ft. 5.3 in. (5.01 m)

t
Limb risers and protection items for roll-over
protective structure

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozer
111-10 General Specirica tions TM- 1136 (Mar-84)

750 LGP BULLDOZER DIMENSIONS

3.54in.(9OInm)’
w/swamp shoe

15 in.
I3Rl mm\ x x 15 in.
(381 mm)

~-17R.5in.(5.3Om)--~
Limb risers and brush-protection assembty for rdl-over
protective structure

Litho in U.S.A.
JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) General Specifications III-11

CUSTOMARY HARDWARE TORQUE

Check all cap screws and nuts, which can be easily

reached, to be sure they are tight. If hardware is loose,
tighten it to torque shown on chart below unless a spe-
cial torque is specified.

NOTE: Torques shown are for dry (no lubrication on

threads) hardware.

NOTE: Torque wrench tolerance is +- 10 percent of

specified torque.

Customary Hardware

Cap Screw
0
Grade B Grade D
Q ‘C
\
Grade F
Size-Inches
lb-ft. (N-m) lb-ft. (N-m) lb-ft. (N-m)
l/4
5/16 -w-w -m-s
ii I::{ :: t::j
3/a -e-s m-m-
35 033)
7/16 35 (47) 55 ?I (108)
l/2 85 (il5j 120 (163)
9/16 :i (Iii{ 130 (176) 175 (237)
5/8 105 (142) 170 (230) 240 (325)
3/4 185 (251) 300 (407) 425 (576)
7/8 160 (217) 445 (603) 685 (929)
1 250 (339) 670 (908) 1030 (1396)
l-1/8 330 (447) 910 (1234) 1460 (1979)
l-1/4 480 (651) 1250 (1695) 2060 (2793)

Litho in U.S.A.
I Genera/ information JD750 Crawler Bulldozer
III-12 General Specifications TM- 1136 (Mar-84)

METRIC HARDWARE TORQUE SPECIFICATIONS

NOTE: Torques shown are for hardware with SAE NOTE: Torque wrench tolerance is _t 10 percent of
30W oil on threads. specified torque.

Metric Standard Thread

Thread 8.8 10.9 12.9

N-m (lb-ft) N.m (lb-R) N*m (lb-R)

M5 5.9 ( 4.4) 7.9 ( 5.8) 9.8 ( 7.2)

M6 9.8 ( 7.2) 13.8 ( 10.2) 16.7 ( 12.3)
M8 24.6 ( 18.1) 34.4 ( 25.4) 40.2 ( 29.6)
Ml0 48.1 ( 35.5) 67.8 ( 50.0) 81.5 ( 60.1)
Ml2 84.4 ( 62.2) 118.0 ( 87.0) 142.0 (105.0)
Ml4 133.0 ( 98.0) 187.0 (138.0) 226.0 (167.0)
Ml6 206.0 (152.0) 290.0 (214.0) 348.0 (257.0)
Ml8 285.0 '(210.0) 398.0 (294.0) 476.0 (351.0)
M20 402.0 (296.0) 570.0 (420.0) 677.0 (499.0)
M22 540.0 (398.0) 765.0 (564.0) 914.0 (674.0)
M24 697.0 (514.0) 980.0 (723.0) 1180.0 (870.0)

Metric Fine Thread

Thread 8.8 10.9 12.9

N-m (lb-tt) N*m (lb-ft) N-m (lb-tt)

M8xl 26.5 ( 19.5) 37.3 ( 27.5) 44.2 ( 32.6)

MlOxl 47.1 ( 34.7) 68.8 ( 50.7) 81.5 ( 60.1)
Ml2 x 1.5 88.4 ( 65.2) 123.0 ( 91.0) 147.0 ( 108.0)
Ml4 x 1.5 147.0 (108.0) 206.0 ( 152.0) 246.0 ( 181.0)
Ml6 x 1.5 221.0 (163.0) 309.0 ( 228.0) 373.0 ( 275.0)
Ml8 x 1.5 319.0 (235.0) 451.0 ( 333.0) 540.0 ( 398.0)
M20 x 1.5 451.0 (333.0) 628.0 ( 463.0) 755.0 ( 557.0)
M22 x 1.5 599.0 (442.0) 845.0 ( 623.0) 1030.0 ( 760.0)
M24x2 765.0 (564.0) 1080.0 ( 796.0) 1275.0 ( 940.0)
M26x2 1130.0 (833.0) 1570.0 (1158.0) 1915.0 (1412.0)

Litho in U.S.A.
JD 750 Crawler Bulldozer Genera/ lnforrna tion I
TM- 1136 (Mar-84) General Specifications III-13

O-RING BOSS FITTING

SERVICE RECOMMENDATIONS
1. Inspect boss O-ring seat. It must be free of dirt and
defects. If repeated leaks occur, inspect for defects with
a magnifying glass. Some raised defects can be re-
moved with a slip stone.

Occasionally a lower durometer O-ring will seal

against a rough seat. If neither of these solutions work,
the component must be replaced.

2. Put hydraulic oil, petroleum jelly or soap on the O-

ring. Put a thimble over the threads to protect O-ring
from nicks. Slide O-ring over the thimble and into the
turned down section of fitting.

For angle fittings, loosen special nut and push special

washer against threads so O-ring can be installed into
the turned down section of fitting.

3. Turn fitting into the boss by hand until special

washer or washer face (straight fitting) contacts boss
face and O-ring is squeezed into its seat.

4. To position angle fittings, turn the fitting counter-

clockwise a maximum of one turn.

5. Tighten straight fittings to the torque valve shown

in chart. For angle fittings, tighten the special nut to
valve shown in the chart while holding body of fitting
with a wrench.

STRAIGHT FITTING OR SPECIAL NUT TORQUE (1)

Thread Number Of
Size (lb-ft) Flats2
316-24 UNF 6 (6) 2
7116-20 UNF 12 (9) 2
l/2-20 UNF 16 (12) 2
9116-18 UNF 24 (18) 2
314-16 UNF 46 (34) 2
710-14 UNF 62 (46) l-112
l-1116-12 UN 102 (75) 1
l-3/16-12 UN 122 (90) 1
l-5116-12 UN 142 (105) 314
l-5/6-12 UN 190 (140) 314
1-710-12 UN 217 (160) 112

1. Tolerance f 10%.

2. To be used if a torque wrench cannot be used. After tightening

fitting by hand, put a mark on nut and boss; then tighten special nut
or straight fitting the number of flats shown.

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I General Information JD750 Crawler Bulldozer
III-1 4 General Specifications TM- 1136 (Mar-84)

TUBE AND HOSE FITTING, 37O FLARE AND 30° CONE SEAT
CONNECTOR SERVICE RECOMMENDATIONS

1. Inspect the flare and the flare seat. They must be 4. Align the tube with the fitting before attempting to
free of dirt and defects. If repeated leaks occur, inspect start the nut. Failure to do so can cause a deformed flare
for defects with a magnifying glass. If burrs and raised and subsequent leaks. Install hoses without twists. A
nicks on the connector body cannot be removed with a twisted hose attempts to straighten out when pressure
slip stone, replace the connector. is applied. This exerts a torque on the connection, even-
tually causing failure.
2. Defects in the tube flare cannot be repaired. Re-
place the tube. Over-tightening a defective flared fitting 5. Lubricate the connection with hydraulic fluid, pe-
will not stop leaks. troleum jelly or soap. Tighten the swivel nut by hand until
it is snug.
3. As a field repair, a ductile truncated cone shaped
washer can be used between the tube flare and connec- 6. Mark a line across the nut and connector body.
tor body. These washers are soft enough to fill defects in This line will serve as a visual indicator as to whether the
the seat and flare. They will also seal the connection. nut has been tightened and by how much.
Ductile washers are available from industrial supply
houses. 7. Using two wrenches, one on the connector body
and a torque wrench on the nut, tighten the nut to the
torque value as shown in the chart. In the case of a hose,
it may be necessary to use three wrenches to prevent
twisting.

TUBE AND HOSE FITTING, 37O FLARE AND 30“ CONE SEAT CONNECTOR TORQUE

Thread Torque’ New* Used3

Size N-m (lb-R) Number of Fiats Number of Flats
318-24 UNF 8 (6) 2-l/2 1
7118-20 UNF 12 (9) 2-112 1
112-20 UNF 16 (12) 2-l/2
Q/18-18 UNF 24 (18) 2 1
314-18 UNF 46 (34) 2 1
718-14 UNF 62 (46) l-112 1
l-1/16-12 UN 102 (75) 1 314
l-3116-12 UN 122 (90) 1 314
l-5/16-12 UN 142 (165) 314 314
l-518-12 UN 190 (146) 314 314
l-718-12 UN 217 (-0) 112 l/2

1. Tolerance of + 10%.

2. To be used if a torque wrench cannot be used. After tightening fitting by hand, put a mark across the fittings, then tighten fitting the num-
ber of fiats shown.

3. Flare connection seal by deforming or squeezing the tube between the nut and the connector. More deformation is possible with new
parts than with old. Therefore, if a torque wrench is not used for re-assembly, the values in this column must be used to prevent damage.

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 JD ?50 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) General Specifications 111-15

SAE FOUR BOLT FLANGE FITTING SERVICE RECOMMENDATIONS

1. inspect the sealing surfaces for nicks or 4. For single piece flange; put hydraulic line in the
scratches, roughness or out-of-flat condition. Scratches center of the flange and install four cap screws. With the
cause leaks. Roughness causes seal wear. Out-of-flat flange centrally located on the port, hand tighten cap
causes seal extrusion. If these defects cannot be pol- screws to hold it in place. Do not pinch O-ring.
ished out, replace the component.
5. For both single piece flange and split flange, be
2. install the correct O-ring (and backup washer if sure the components are properly positioned and cap
required) into the groove using petroleum jelly to hold it screws are hand tight. Tighten one cap screw, then
in place. tighten the diagonally opposite cap screw. Tighten the
two remaining cap screws. Tighten all cap screws within
3. For split flange; loosely assemble split flange the specified limits shown in the chart.
halves, being sure that the split is centrally located and
perpendicular to the port. Hand tighten cap screws to DO NOT use air wrenches. DO NOT tighten one cap
hold parts in place. Do not pinch O-ring. screw fully before tightening the others. DO NOT over-
tighten.

SAE FOUR BOLT FLANGE FtTTfNG TORQUE

Torque2
Nominal Cap Screw N’m (lb-ft)
Flange Size Size1 Min. Max. Min. Max.
112 5116 -.13 UNC 20 31 (15) (23)
314 310 - 16 UNC ’ 28 54 (21) (40)
1 318 - 16 UNC 37 54 (27) (40)
l-114 ?I16 - 14 UNC 47 85 (35) (63)
l-112 l/2 - 13 UNC 62 131 (46) (97)
2 l/2 - 13 UNC 73 131 (54) (97)
2-l/2 112 - 13 UNC 107 131 (79) (97)
3 S/0- 11 UNC 158 264 (117) (195)
3-112 518 - 11 UNC 158 264 (117) (195)
4 5/8- 11 UNC 158 264 (117) (195)
5 510 - 11 UNC 158 264 (117) (195)

I. SAE Grade 5 or better cap screws with plated hardware.

2. Tolerance f 10%. The torques given are enough for the given size connection with the recommended working pressure. Torques can be
ncreased to the maximum shown for each cap screw size if desired. Increasing cap screw torque beyond this maximum will result in flange
and cap screw bending and connection failures.

Litho in U.S.A.
I General Information JD750 Crawler Bulldozer
III-16 General Specifications TM- 1136 (Mar-84)

O-RING FACE SEAL FllTlNG SERVICE RECOMMENDATIONS

1. Inspect the sealing surfaces for nicks or 3. Install fitting and hand tighten until snug. To posi-
scratches, roughness, or out-of-flat condition. tion angle fittings, turn fitting counterclockwise a maxi-
Scratches cause leaks. Roughness causes seal wear. mum of one turn.
Out-of-flat causes seal extrusion. If these defects can-
not be polished out, replace the component. 4. Tighten fitting for nut to torque value shown in
chart per dash size stamped on fitting.
2. Lubricate O-rings and male threads using petrole-
um jelly. Use one wrench to hold connector body and another
wrench to tighten nut. When tightening a fitting on a
For O-ring face seal fittings, push 0-ring into groove. hose, it may be necessary to use three wrenches to
prevent twisting hose; one on the connector body, one
For O-ring boss fittings, put a thimble over the on the nut, and one on the body of hose fitting.
threads to protect O-ring from nicks. Slide O-ring over
the thimble and into the turned down section of fitting.

For angle fittings, loosen special nut and push special

washer against threads so O-ring can be installed’ into
the turned down section of fitting.

O-RING FACE SEAL FITTING TORQUE (1)

O-Ring Face Seal End O-Ring Boss End

Nominal Thread Swivel Nut Bulkhead Thread Straight Fitting or
Tube O.D. Dash Size Torque Nut Torque Size Jam Nut Torque
mm in. Size in. N-m lb-R Wm lb-B in. N’m lb-H
4.76 0.168 -3 --- 318-24 8 6

6.35 0.250 -4 9116-18 16 12 5.0 3.5 7116-20 12 9

7.94 0.312 -5 - --- - - 112-20 16 12

9.52 0.375 -6 11116-16 24 18 9.0 6.5 9116-18 24 18

12.70 0.500 -8 13116-16 50 37 17.0 12.5 314-16 46 34

15.88 0.625 -10 1-14 69 51 17.0 12.5 716-14 62 46

19.05 0.750 -12 l-3116-12 102 75 17.0 12.5 l-1/16-12 102 75

22.22 0.875 -14 l-3116-12 102 75 17.0 12.5 q-3116-12 122 90

25.40 1 .ooo -16 l-7116-12 142 105 17.0 12.5 l-5116-12 142 105

31.75 1.250 -20 l-11116-12 190 140 17.0 12.5 l-518-12 190 140

38.10 1.500 -24 2-12 217 160 17.0 12.5 l-718-12 217 160

1. Tolerance: +15-20%.

Litho in U.S.A.
JD750 Crawler Bulldozer General Information I
TM- 1136 (Mar-84) Predelivety, Delivery, and After-Sale Services IV-1

Group IV
PREDELIVERY, DELIVERY, AND
AFTER-SALE SERVICES
TEMPORARY STORAGE 1. Air Cleaner
After receiving your crawler from the factory and be-
fore putting the machine into temporary storage perform
the following checks:

1. Check battery electrolyte level and charge the bat-

tery, if necessary.

2. Check coolant level in the radiator. The coolant

should be maintained at a level midway between the
radiator core and filler neck.

3. Fill the fuel tank.

4. Check crankcase oil level. Oil should be at top

mark of dipstick after crawler has been shut down for 10
minutes.
A-Restriction Indicator D-Wing Nut
5. Relieve hydraulic pressure by stopping engine, B-Cover E-Primary Element
lowering all equipment and operating control levers until C-Nut
system fails to respond.

PREDELIVERY SERVICE
Because of the shipping factors involved, plus extra
finishing touches that are necessary to promote cus-
tomer satisfaction, proper predelivery service is of prime
importance to the dealer and the customer.

If adjustments are required, procedures are found in

the After-Sale section.

Install blade before starting the following predelivery

points.

Use the following list when preparing a unit for deliv-

ery to the customer.
F-Wing Nut G-Safety Element

Fig. 7 and IA-Air Cleaner

Check air cleaner restriction indicator. If red signal

locks in full view, look for restriction or blockage in air
intake system.

Air cleaner elements checked Yes No

Restriction in system Yes No

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozk
IV-2 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

2. Fuel Filters 4. Batteries

fig. P-Fuel Filter / Wl”3

fig. 4Batteries

Check fuel filter for sediment. Drain if necessary. To Check battery electrolyte level. If distilled water is not
drain: available, use clean soft water. Avoid use of hard water.
1 - Loosen drain plug. Remove foreign material from top of battery and coat
2 - Work fuel pump primer lever until fuel, free of bub- terminals with petroleum jelly.
bles, flows from filter opening. IMPORTANT: Never add water to battery in freez-
3 - Tighten drain plug. ing weather unless engine is to be run 2 or 3 hours to
4 - Bleed fuel system as follows: assure mixing of water and electrolyte.
A - Loosen bleed plug.
B - Work fuel pump primer lever until fuel, free of Check battery connections.
bubbles, flows from filter opening. Punch date code on battery.
C - Tighten bleed plug.
Yes No Water added Yes No
SeUiment present in filter
Batteries checked and serviced Yes No

3. Air Intake Hose

5. Fuel Tank

Fig. 3-Air Make Hose Connections

Check clamps on hose connecting air cleaner and

engine. Tighten two hose clamps. Inspect hose for 743681

cracks. Fig. S-Fuel Tank

Air intake hose checked Yes No Check fuel tank level. If low, add sufficient fuel to fill
Loose connections Yes No
the tank. Capacity is 73 gal. (276.6 L). Check fuel sys-
tem for leaks.
Fuel tank level Full 7/2-Full Empty

Litho in U.S.A.
 JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Predelivety, Delivery, and After-Sale Services IV-3

6. Fuel Tank Sump Check coolant level in radiator. Coolant level should
be to the bottom of the filler neck. Add permanent type
antifreeze if cold weater is expected. If coolant level is
low, check cooling system for leaks.

Do not use methoxy propanol antifreeze (such as

Dowtherm 209 antifreeze or its equivalent) in the cool-
ant solution. It may damage the cylinder sleeves and
seals. This antifreeze is also not compatible with either
the precharge or service filters.
Radiator coolant level checked Yes No
Coolant or antifreeze added Yes No

I 8. Crankcase Oil Level

Fig. &We/ Tank Sump

Open drain cock (A) located at bottom of fuel tank.

Drain fuel until all sediment drains out. Close and tighten
drain cock.

NOTE: Drain sump aftercrawlerhas been shut down

for at least 2 hours.
Fuel tank sump drained Yes No
Filter checked Yes No

7. Radiator

A-Oil Filler Cap B-Dipstick

Fig, d-crankcase Oil Level

Check crankcase oil level with unit on level ground

and engine shut off. Wait 10 minutes for oil to drain into
oil pan. If oil level is at or below bottom mark on dipstick,
add sufficient oil of the proper viscosity and type speci-
fied in the Lubrication section to bring oil level to be-
tween marks on dipstick. Do not operate engine with oil
level below the bottom mark.
Crankcase oil level checked Yes No
Oil added Yes No
753061

Fig. 7-Radiator Filler Cap

A
CAUTION: Do not remove radiator filler cap
until engine is cool. Then loosen cap slowly to
the stop to relieve any excess pressure before re-
moving cap completely.

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozer
IV-4 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

9. Front Idlers, Track Rollers and 10. Splitter Gearbox Oil Level
Carrier Rollers Oil Levels

A-Front Idler Check Plug C-Carrier Roller Check Plug

B-Track Roller Check Plug

Fig. O-Track Area Oil Levels

Check oil level in the carrier rollers. Oil level should be

T81433
at check plug. If low, add oil specified in the Lubrication
A-Dipstick B-Filler Tube
section to bring level up to check plug.
Fig. 7U-Sp/itter Gearbox Oil Level
Check oil level in the front idlers and track rollers as
The filler tube and dipstick are located on the rear of
follows:
the splitter housing under the floorboard plate.
1 - Thoroughly clean the nozzle and around the plug
end of the shaft.
IMPORTANT: DO NOT overfill. Overfilling may
2 - Remove plug and O-ring.
cause overheating.
3 - Using a JD-313 Lube Nozzle Kit, insert the noz-
zle in the shaft as far as it will go.
Park crawler on a level surface and stop the engine.
4 - Force oil slowly into the shaft until oil is flowing
Remove dipstick. Oil level should be between marks on
out of roller indicating roller or idler is full.
the dipstick. If oil level is low, fill with oil specified in the
5 - Remove the nozzle and install O-ring and plug.
Lubrication section.
Front idler, track roller and carrier roller
oil /eve/s checked Yes No
Yes No
Replace dipstick. Do not overtighten dipstick.
Oi/ added
Splitter gearbox oil level checked Yes No
Oil added Yes No

Litho in U.S.A.
JD750 Crawler Bulldozer General lnforma tion I
TM- 1736 (Mar-84) Predeliyety, Delivery, and After-Sale Services IV-5

11. Inner and Outer Final Drive Housing Oil 12. Hydrostatic Transmission Oil Level
Level

A-Oil Level Window B-Fill Plug

Fig. 13-Transmission Sump

Park crawler on a level surface and stop the engine.

Transmission oil level should be halfway up in oil level

window.
A-Level-Filler Plug B-Drain Plug

A
CAUTION: The hydrostatic transmission sys-
Fig. 7 1-Inner Final Drive Housing tem is a sealed design and has no vent. Re-
move filler plug slowly to release pressure. When
replacing the filler plug, be sure it is screwed down
tight and the O-ring is in good condition.

If oil is not visible in window, add enough oil specified

in the Lubrication section to bring up to this level. Check
transmission system for leaks if oil level is low.

Total capacity is 28 gal. (106 L).

Transmission oil level checked Yes No

Oil added Yes No

755862N

A-Level-Filler Plug B-Drain Plug

Fig. 72-Outer final Drive Housing

Check the oil levels of the inner and outer final drive
housings. Oil level should be at level-filler plug. If low,
add oil specified in the Lubrication section to bring level
up to fill plug.
her and outer final drive housing oil
level checked Yes No
Oil added Yes No

Litho in U.S.A.
 I General lnforma tion JD750 Crawler Bulldozer
IV-6 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

13. Hydraulic Oil Level 14. Alternator-Fan-Compressor Belt

Tension

T59oiK)Y

A-Oil Level Window B-Fill Plug

Fig. 15-Checking Belt Tension
Fig. 14-Hydraulic Reservoir
Check alternator belt tension. A force of 18 lb. (80 N)
Check oil level with crawler on a level surface, blade (8 kg) midway between pulleys should deflect belt 1/2-
on ground, and ripper (if equipped) in transport position. inch (13 mm).
Stop the engine.

Hydraulic oil level should be halfway up in oil level

window.

A
CAUTION: The hydraulic reservoir is com-
pletely closed and pressurized. Slowly re-
move the fill plug to relieve the reservoir pressure.
When replacing the fill plug, be sure it is screwed
down tight and the O-ring is in good condition.

If oil is not visible in window, add enough oil specified

in the Lubrication section to bring up to this level. Check
hydraulic system for leaks if oil level is low.
Fig. l&Checking Strand Tension
Reservoir ‘capacity is 28 gal. (106 L).
If belt gauge is used, tighten used belt to 90 lb. (400 N)
Hydraulic oil level checked Yes No (41 kg) strand tension. Tighten new belt to 135 lb. (600
Oil added Yes No N) (61 kg).

If adjustment is required, see the After-Sale Inspec-

tion section.

Litho in U.S.A.
JD 750 Crawler Bulldozer General Information
TM- 1136 (Mar-84) Predelivery, Delivery, and After-Sale Services

fig. 7 7-Checking Belt Tension Fig. PO-Checking Strand Tension

Check fan belt tension. A force of 12 lb. (53 N) (5 kg) If belt gauge is used, tighten used belt to 90 lb. (400 N)
midway between pulleys should deflect belt l/2-inch (13 (41 kg) strand tension. Tighten new belt to 135 lb. (600
mm). NJ (61 kg).

If adjustment is required, see the After-Sale Inspec-

tion section.

Alternator belt tension -Ibs. (N) (kg) tension

-.-..-Jnch (mm) flex
Fan be/t tension ..-..-Ibs. (N) (kg) tension
-inch (mm) flex
Compressor belt tension -Ibs. (N) (kg) tension
.-.-.-inch (mm) flex

15. Engine Speeds

Warm up engine and attach a tachometer in the en-
gine rotation tool hole to check engine speeds.
Fig. 18-Checking Strand Tension
No-load, fast-idle speed should be 2300 - 2320 rpm.
If belt gauge is used, tighten used belt to 90 lb. (400 N)
Slow idle should be 975 - 1000 rpm.
(41 kg) strand tension. Tighten new belt to 100 lb. (445
NJ (45 kg).
If engine speeds need adjustment, proceed as fol-
If adjustment is required, see the After-Sale Inspec-
lows:
tion section.

Fig. 79-Checking Belt Tension

Check compressor belt tension. A force of 15 lb. (67

N) (7 kg) midway between pulleys should deflect belt
l/4-inch (6 mm).

Litho in U.S.A.
I General Information JD750 Crawler Bulldozer
IV-8 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

F. Engage engine cold weather disconnect clutch.

Rotate the injection pump lever fully forward until the
low idle stop screw in the injection pump cover is con-
tacted. Record the engine speed. It should read 975 to
1000 rpm. If not correct, adjust low idle stop screw (6) to
obtain the specified speed.

G. With the injection pump lever held against the low

idle stop, adjust the low idle override screw (5) until the
engine speed just begins to raise above the low idle
speed set in Step F. Then back off screw i/2 turn and
tighten.

H. Reconnect the engine speed control cable (2).

IMPORTANT: Whenever either the high or low idle

speeds are adjusted on the injection pump, the en-
gine speed control lever to injection pump cable ad-
justment has to be made. Refer to Section 90 for this
adjustment.
T45976N

I-Injection Pump Lever 4-Fuel Injection Pump Use the following test to check engine speed control
l--Speed Control Cable ~-LOW Idle Override
linkage and automatic control valve linkage synchroni-
3-High Idle Stop Screw
~-LOW Idle Stop zation. This test requires a 100 ft (305 m) flat area to
drive the machine.
Fig. PI-Engine Speed Adjustment
1. Run the engine at slow idle.
NOTE: Use to set fast and slow idle for engine
operation.
2. Move the FNR speed control handle forward to
approximately 3/4 speed position
A. Disengage engine cold weather disconnect
clutch.
3. Slowly and evenly increase engine rpm at a rate in
which the machine will travel approximately 100 ft (305
B. Disconnect engine speed control cable quick dis-
m) when fast idle position is obtained.
connect end (2, Fig. 21) from injection pump lever (1).

4. Run the engine at fast idle.

C. Check injection pump throttle lever for proper op-
eration. Check to see that there is no debris between the
5. Slowly and evenly decrease engine rpm at a rate in
high and low idle stop screws and stops, and that lever
which the machine will travel approximately 100 ft (305
override works freely.
m) when slow idle position is obtained.
D. Warm engine up. Run engine and rotate injection
6. The machine must not slow down or stop at any
pump throttle lever fully to the rear until it touches the
point in the rpm range. If a rpm decrease (dead spot)
high idle stop (3). Record engine speed. It should read
occurs, the engine speed control linkage and automatic
2300 to 2320 rpm. If not correct, adjust injection pump
control valve linkage are not synchronized. See Section
high idle stop screw to obtain specified speed.
90 of this manual for adjustment.

E. Back out the low idle override screw (5) on the Engine speeds checked Yes No
injection pump lever far enough to make sure the low Adjustment required Yes No
idle stop screw (6) in the injection pump cover is being
contacted.

Litho in U.S.A.
JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Predelivety, Delivery, and After-Sale Services IV-9

i6. Track Sag Adjustment 17. Seat Operation

Fig. 22-Measuring Track Sag

Check the amount of sag in center of track between

front carrier roller and front idler. Sag should be 1 to
l-l /2 inches (25.4 to 38 mm). If adjustment is required,
see the After-Sale Inspection section. D-Weight Adjustment
A-Height Adjustment
B-Weight Adjustment Indicator
Check the vertical and horizontal movement of the C-Forward/Rearward E-Tilt Adjustment
front idler assembly on the track frame. If adjustment is Adjustment
required, see the After-Sale Inspection section.
Fig. 23-Seat Adjustments

Check the carrier rollers for proper alignment with the To adjust height, push down on lever (A) to move seat
track. If adjustment is required, see the After-Sale In- to the desired position. Release lever. To adjust weight,
spection section. turn knob (8) until indicator (D) is flush with tube when
seated. Use flip-out handle on the knob for rapid adjust-
Track tension checked Yes No
ment. To adjust forward or rearward, lift up on lever(C)
Front Idler and carrier rollers wear checked Yes No
and slide seat to the desired position. Release lever. To
Adjustment required Yes No
adjust tilt, lift up on lever (E) to flip seat backward or
push down to tilt seat forward. Release lever.
Seat operational Yes No

Litho in U.S.A.
 I General lnforma tion JD750 Crawler Bulldozer
IV-10 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

18. Indicator Lights and Gauges LIGHl

When operating the crawler, check the following

gauges for correct operation.

ORANG

LIGHT
RED GREEN
ORANGE

Fig. Z&Voltmeter

With key switch on and engine off, the indicator

should be in the lower left light green zone.

T43407 When cranking the engine, the indicator will fall into
743407 the left-hand orange zone. When the engine starts, the
Fig. 24-Transmission Oil Pressure Gauge indicator should move to stay in the right-hand light
green zone.
Normal operating range is in the light green zone.

(66%) (93OC)
Check transmission oil pressure gauge during oper- 15OOF ~200O.F
ation. If transmission oil pressure is not in the light green
zone, shut off engine. Check transmission oil level. If oil LIGHT GREEN
RED ORANGE
is at proper level, troubleshoot the transmission system, ZONE

checking for bent or broken lines and hoses. Also check (52°C)
for excessive leakage. 125OF

Transmission oil pressure may register slightly above

the green zone in neutral or at full engine speed.

RED LIGHT
ORANG

T43409
T43.40'1
Fig. 27-Transmission Oil Temperature Gauge

Do not permit this temperature to exceed 2OO’F

(93%). If the temperature reaches this point during op-
eration, stop the engine and locate the trouble.

Fig. 25Engine Oil Pressure Gauge

If the indicator hand of the engine oil pressure gauge

drops into the red-orange zone, stop the crawler and
check engine oil level. If oil level is not low, check for
restrictions in oil lines or incorrect viscosity oil.

Litho in U.S.A.
JD750 Crawler Bulldozer General lnforma tion I
TM- 7 136 (Mar-84) Predelivery, Delivery, and After-Sale Services IV-11

The transmission oil filter restriction indicator light

glows red also if the pressure switch located with the
engine oil pressure sending unit is faulty, if the engine oil
pressure is low, or if the oil is cold during initial startup.

T30897N
--8
4
Fig. 28-Engine

Normal operating
zone.
Water Temperature Gauge

temperature
130897

is in the light green

138471N
c3
Fig. 30-Hydraulic Oil Filter
If the indicator hand goes into the red-orange zone, Restriction indicator Light
check cooling system.
NOTE: Light should glow, if operative, with key
switch in start position and engine off.

When the engine is running, the hydraulic oil filter

indicator light should go out. If light glows red while the
engine is running, stop engine and determine cause.
Light may glow during initial operation until oil warms. 1

Fig. PBTransmission Oil filter Gauges operational Yes No

indicator Light

19. Light Operation

NOTE: Light should glow, if operative, with key
switch in start position and engine off.

When the engine is running, the transmission oil filter

indicator light should go out, indicating that there is no
restriction in the transmission and oil filters. If light glows
red while the engine is running, stop engine and deter-
mine cause.

A-Front Lights 6-Rear Light

Fig. 31-Lights

All lights are controlled by the “push-pull” light

switch. To turn on lights, pull out switch knob. To turn
off lights, push in switch knob. The key switch must be in
the “on” position before the lights will operate.

Lights operational Yes No

Litho in U.S.A.
 I General lnforma tion JD750 Crawler Bulldozer
IV-12 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

20. Transmission Control 21. Hydraulic Brake (Park Brake)

T5634.4

A-Park Brake Pedal B-Park Brake Lock Knob

Fig. 33-Park Brake

TlJ416

A-Forward and Reverse B-Neutral Lock Lever When the brake pedal is depressed, the forward and
Speed Control Lever C-Hand Throttle
reverse speed control lever returns to neutral automati-
Fig. 32-Transmission Shifting
cally.

Move the forward and reverse speed control lever Operate.the forward and reverse speed control lever
forward from “neutral” to provide control of forward to verify braking in neutral.
ground speeds from zero to maximum.
Brakes operational Yes No
Move the lever rearward to control reverse ground
speeds from zero to maximum. The forward and reverse
speed control lever has a Z pattern movement to pro-
vide a positive location of the “neutral” position.

The forward and reverse speed control lever in “neu-

tral” gives a braking effect. Engine braking is available
as the control lever passes from forward or reverse
speeds to neutral.

When the brake pedal is depressed, the forward and

reverse speed control lever returns to the neutral posi-
tion.

Transmission oDerational Yes No

Litho in U.S.A.
JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Predelivety, Delivery, and After-Sale Services IV-13

22. Steering

T53008

A-Left Steering Lever B-Right Steering Lever

Fig. 34-Steering Levers

Pull steering lever (right lever for right turn etc.) be-
yond the neutral position. This allows the tracks to travel Fig. 35Lift Cylinder Yokes
in opposite directions. DO NOT attempt to pull both and Trunnions (6 Points)

levers into this rearward position to reverse direction. Yes No

Lubricant required

The same principle applies with pedal steering. De-

pressing pedal beyond neutral will reverse track rota-
tion.

Steering operational Yes No

23. Lubrication
The crawler bulldozer was checked and lubricated
before it left the factory. However, to insure customer
satisfaction, check each lubrication point shown in the
following pages. Lubricate with several strokes of John
Deere Multi-Purpose Grease, if necessary.

Fig. 36-Crossmember (Low Ground Pressure)

Crossmember grease fittings (A) for Low Ground

Pressure machines are serviced through the grille.

Lubricant required Yes No

Litho in U.S.A.
I General lnforma tion JD 750 Crawler Bulldozer
IV-14 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

Fig. 39-Universal Joints (4 Points)

Lubricant required Yes No

Fig, 37-Pitch Adjusting Jack and

Socket (Dozer Blade) (2 Points)

Lubricant required Yes No

Fig. 40-Left and Right Track

Frame Pivot Shaft (2 Points)

Lubricant required Yes No

Fig. 38-Tilt Adjusting Jacks

(Angle Dozer Blade) (4 Points)

Lubricant required Yes No

Litho in U.S.A.
JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Predelivety, Delivery, and After-Sale Services IV-15

Start crawler with neutral lock lever in the up (LOCK)

position. The transmission is locked in the neutral posi-
tion.

Move neutral lock lever to the down (UN-LOCK) posi-

tion. The forward and reverse speed control lever is now
unlocked, which makes it possible to drive the crawler.

Neutral lock lever operational Yes No

25. Accessible Hardware Torque Values

Check all accessible cap screws and nuts for proper
tightness. If hardware seems loose, tighten it to the
proper torque. Group Ill gives correct torque values for
various bolts and cap screws. The table lists torques in
the U.S. unit of measure (lb-ft) and SI metrics (N-m).
Fig. 41-Left and Right Track
Most hardware used is high-strength (note dashes on
Frame Pivots (2 Points)
hex. heads).
Remove plug. If fluid level is low, fill to topof shaft with
a Multi-Purpose GL-5 Gear Oil - SAE 8OW-90 weight The types of bolts and cap screws are identified by
meeting MIL-L-210% specifications or an equivalent. head markings as follows:
Replace plug.
Plain Head: regular machine bolts and cap screws.
Left and right track
frame pivots checked Yes No
3-Dash Head: tempered steel high-strength bolts and
Oil added Yes no cap screws.

24. Neutral Lock Lever Operation 6-Dash Head: tempered steel extra high-strength
bolts and cap screws.

Machine bolts and cap screws 7/8-inch and larger are

sometimes formed hot rather than cold, which accounts
for the lower torque.

A// accessible hardware torqued Yes No

A-Run Position B-Lock Position

Fig. 42-Neutral Lock Lever

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozer
IV-16 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

26. Radiator Air Flow Pre-Test Inspection 27. Radiator/Oil Cooler Air Flow Test
1. Apply parking brake, put transmission in neutral,
lock reverser lever in neutral, and start engine. Raise
loader and install boom lock bar. Stop engine.

2. Remove side shields and grill screen.

3. Divide the surface of radiator into 16 equal

squares with white chalk lines on the front of the radia-
tor.

4. Install a D-01 084AA Tachometer/Temperature

Reader on the machine. Start engine and check low idle.
Low idle must be 975-1000 rpm.
x3073

Fig. 42A-For Belt Tension

5. Run engine at 1075 rpm.

A
CAUTION: DO NOT remove radiator cap until
radiator top tank feels cool. 6. Connect JT05529 Air Flow Meter to D-27501 BM
Digital-Multimeter or JT27504 Heavy Duty Digital Multi-
1. Check coolant level. meter. Turn switch on multimeter to 20 volts AC.

2. Check belt tension. A force of 53 N (12 lb force) on IMPORTANT: Unit is equipped with a blower fan
belt halfway between pulleys must move belt 13 mm (sucker fan is optional.).
(0.500 in.). Adjust belt if necessary.
Direction arrow on Air Flow meter must be away from
3. Check radiator fin condition. Make sure fins are radiator for blower fan and towards radiator for sucker
not bent or damaged. fan.

4. Check fan blade tips, shroud, and baffle, for dam- 7. Hold Air Flow Meter in direct contact with radiator
age. Fan blade tip to shroud distance must be equal at with direction arrow toward radiator. Hold multimeter
top and bottom. with other hand and stand to side of unit to prevent
interference with air flow. Make a record of the multi-
5. Check for blower fan installation (sucker fan op- meter reading for each square.
tional).
I,’ ,, : 8. Compare readings to Pre-Delivery Inspection re-
‘<.: .’ ,,
., ., cords or repeat entire procedure on a new unit, with the
same equipment for comparison. If readings are re-
duced by 20% or more, remove oil cooler. Clean exter-
nal surfaces of both oil cooler and radiator. Install oil
cooler.

Fig. 42B-Checking Radiator Cap

6. Connect radiator cap to a D-05104ST Pressure

Pump (A). Raise pressure until cap valve opens. Valve
must hold pressure at 43 to 50 kPa (0.43 to 0.51 bar)
(6.25 to 7.50 psi) for one minute. If pressure decreases,
install a new cap.

Litho !n U.S.A.
JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Predelivery, Delivery, and After-Sale Services IV-17

Air Flow Test Readings Using the operator’s manual as a guide, be sure that
the owner understands these points thoroughly:
Record sum of individual values for future reference:
1. The importance of safety.
2. The importance of lubrication and periodic ser-
vices.
3. The importance of the break-in period.
4. Controls and instruments.
5. How to start and stop the engine.
6. All functions of the hydraulic system.

After explaining and demonstrating the above fea-

tures, have the owner sign the Delivery Receipt and give
the owner the operator’s manual.

28. Final Check AFTER-SALE INSPECTION

The final predelivery procedure is the overall cleanup The purchaser of a new John Deere crawler is entitled
of the crawler. Make the crawler LOOK like a new crawl- to a free inspection at some mutually agreeable time
er with the proper touch-up of chipped paint and a good within the warranty period after the equipment has been
wash job. Deliver to the customer a crawler anyone “run-in,” usually after 50 to 100 hours of crawler oper-
would be proud to own. ation. The terms of this after-sale inspection are outlined
on the customer’s John Deere Delivery Receipt.
DELIVERY SERVICE
The inspection is to make sure that the customer is
A thorough discussion of the operation and service of receiving satisfactory performance from the crawler. At
this new crawler at the time of delivery helps to assure the same time, the inspection should reveal whether or
complete customer satisfaction. Proper delivery should
not the crawler is being operated, lubricated, and ser-
be an important phase of the dealer’s program. A por-
viced properly.
tion of the John Deere Delivery Receipt emphasizes the
importance of proper delivery service.
If the recommended after-sale service inspection is
followed, the dealer can eliminate a needless volume of
Many complaints arise because the owner was not service work by preventing minor irregularities from de-
shown how to operate and service the new crawler veloping into serious problems later on. This will pro-
properly. Devote enough time, at the customer’s conve-
mote strong dealer-customer relations and present the
nience, to introduce the owner to the new crawler. Ex- dealer an opportunity to answer questions that may
plain how to operate and service it.
have arisen during the first few days of operation.

The following procedure is recommended before the During this inspection service, the dealer has the op-
service technician and owner complete the deliveryac- portunity to promote the possible sale of other new
knowledgments portion of the Delivery Receipt.
equipment.

Check operation of all controls and instruments for

freedom of movement and correct operation.

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozer
IV-18 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

1. Engine Crankcase Oil and Filter

Element

NOTE: Check with the customer if oil has been

changed and filter replaced before performing this ser-
vice.

Normal sequence of service is as follows:

Oil and Filter Change - after first 100 hours

- every 200 hours thereafter

If changed, record information below:

Approximate hours at change A

a 748722~

If not, change as follows: 748722

A-Oil Filter Element C-Mounting Surface

B-Nipples

Fig. 45Crankcase Oil Filter Component

A - Remove filter element. (Turn counter-

clockwise.)
B - Clean mounting surface.
C - Apply film of oil to sealing rings.
D - Tighten element until sealing rings touch-
es mounting surface.
E - Turn an additional l-1 /2 turns.
F - Do not overtighten.

5- Fill crankcase with new oil of proper viscosity.

Fig. 43-Engine Crankcase Drain Plug Capacity is 18 quarts (17.0 L) without filter, 20
quarts (18.9 L) with filter.
1 - Run engine to heat oil.
6- Run engine a short time and check for leaks at
2 - Drain oil from engine crankcase.
filter bases and drain plug.
3 - While crankcase is draining, replace filter ele-
7- Stop engine.
ments as follows:
a- Check oil level. Level should be between marks
on dipstick.

Crankcase oil changed Yes No

Oil filter element changed Yes No
Oil added, if any -qts 0-J

Fig, 44-Engine Crankcase Filter Elements

Litho in U.SA.
 JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mgr-84) Predelivety, Delivery, and After-Sale Services IV-19

2. Hydrostatic Transmission Oil Level 3. Hydraulic Oil Level

Park crawler on a level surface and stop the engine. Park crawler on a level surface, blade on ground and
Check oil level in hydrostatic transmission system daily. ripper (if equipped) in transport position. Stop the en-
Oil level should be halfway up in oil level window. gine. Check oil in hydraulic system. Oil level should be
halfway up in oil level window with the blade level on the
.ground and ripper (if equipped) in transport position.

Tl8-378

A-Oil Level Window B-Filler Plug

T5sccQY
Fig. 46-Check and Fill Areas B-Filler Plug
A-Oil Level Window

A
CAUTION: The hydrostatic transmission sys-
Fig. 47-Check and Fill Areas
tem is completely enclosed and pressurized.

A
Remove filler plug slowly to release pressure. When CAUTION: The hydraulic reservoir is com-
replacing fill plug, be sure it is screwed down tight pletely closed and pressurized. Slowly re-
and the O-ring is in good condition. move the fill plug to relieve the reservoir pressure.
When replacing the fill plug, be sure it is screwed
If oil level is low, remove fill plug. Add oil specified in down tight and the O-ring is in good condition.
the Lubrication section until oil level reaches mid-point
on the oil level window. Check transmission system for If oil level is low, remove fill plug located on top of the
leaks if oil level is low. oil reservoir. Add oil specified in the Lubrication section
until oil level reaches midpoint on the oil level window.
Hydrostatic transmission Check hydraulic system for any leaks if oil level is low.
oil level checked Yes No
Hydraulic oil level checked Yes No
Oil added, if any -9ts. (L)
Oil added, if any -9ts. (L)

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozer
IV-20 Predelivery, Delivery, and After-Sale services TM- 1136 (Mar-84)

4. Splitter Gearbox Oil Level 5. PII~;, and Outer Final Drive Housing Oil

181433

A-Dipstick B-Filler Tube

Fig. 48-Splitter Gearbox

Filler tube and dipstick are located on the rear of the

A-Level-Filler Plug B-Drain Plug
splitter housing under the floorboard plate.
Fig. 49-inner Final Drive Housing
IMPORTANT: DO NOT overfill. Overfilling may
cause overheating.

Park crawler on a level surface and stop the engine.

Remove dipstick. Oil level should be between marks

on the dipstick. If oil level is low, fill with oil specified in
the Lubrication section and replace dipstick. Do not
overtighten dipstick.

Splitter gearbox
oil level checked Yes No

Oil added, if any -qts. (L)

T55862N

A-Level-Filler Plug B-Drain Plug

Fig, 50-Outer Final Drive Housing

Check the oil levels of the inner and outer final drive
housings. Oil level should be at check and fill plug. If low,
add oil specified in the Lubrication section to bring oil
level to check and fill plug.
Inner and outer final drive
housing oil level checked Yes No

Oil added, if any -qrs. (L)

Litho in U.S.A.
JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Predelivery, Delivery, and After-Sale Services IV-21

6. Air Cleaner 7. Air Intake Hose

Fig. 53-Air intake Hose Connections

Check clamps on hose which connects air cleaner

and engine. Tighten hose clamps where necessary to
A-Restriction Indicator D-Wing Nut
B-Cover E-Primary Element
prevent dirt from entering engine. Inspect hose for
C-Nut cracks and wear. Check air intake system for leaks.

Loose connections Yes No

8. Alternator-Fan-Compressor Belt
Tension

F-Wing Nut G-Safety Element

X3070

Fig. 51 and 52-Air Cleaner Fig. M-Checking Belt Tension

Check air cleaner restriction indicator. If red signal Check alternator belt tension. A force of 18 lb. (90 N)
locks in full view, remove and clean primary element. (8 kg) midway between pulleys should deflect belt
Replace element if necessary. l/2-inch (13 mm).

NOTE: If cleaning primary element does not return

restriction indicator to normal, replace the safety ele-
men t.

Air cleaner elements checked Yes No

Air cleaner elements cleaned or replaced Yes No

Litho in U.S.A.
 General lnformafion JD750 Crawler Bulldozer
Predelivety, Delivery, and After-Sale Services TM- 1136 (Mar-84)

Fig. 55-Checking Strand Tension Fig. 58-Checking Strand Tension

If belt gauge is used, tighten used belt to 90 lb. (400 N) If belt gauge is used, tighten used belt to 90 lb. (400 N)
(41 kg) strand tension. Tighten new belt to 135 lb. (600 (41 kg) strand tension, Tighten new belt to 100 lb.
NJ (61 kg). (445 N) (45 kg).

.Fig. 56-Adjusting Screws Fig. 59-Adjusting Screws

To adjust, loosen ‘alternator bracket and adjusting To adjust, loosen’the 2 cap screws holding the idler
screws. pulley support onto the idler pulley bracket. Turn cap
screw on side of the idler pulley clockwise. This will
apply outward pressure on the idler pulley. Tighten the 2
cap screws holding the idler pulley support onto the idler
pulley bracket.

Fig. 57-Checking Belt Tension

Check fan belt tension. A force of 12 lb. (53 N) (5 kg)

midway between pulleys should deflect belt i/Zinch
(13 mm).
fig. d&Checking Belt Tension

Check compressor belt tension. A force of 15 lb.

(67 N) (7 kg) midway between pulleys should deflect belt
l/4-inch (6 mm).
Litho in U.S.A.
 JD750 Crawler Bulldozer General lnforma tion I
TM- I 136 (Mar-84) Predelivety, Delivery, and After-Sale Services IV-23

9. Radiator Coolant Level

Fig. 61-Checking Strand Tension

If belt gauge is used, tighten used belt to 90 lb. (400 N)

(41 kg) strand tension. Tighten new belt to 135 lb.
(600 N) (61 kg).

Fig. 63-Radiator Filler Cap

A
CAUTION: Remove radiator filler cap only
when engine is cool. Then loosen the cap
slightly to the stop to relieve pressure before remov-
ing the cap completely.

Check coolant level in the radiator. Coolant level

wc69 should be at the bottom of filler neck. If coolant level is
Fig. 6%Adjusting Screws low, check cooling system for leaks.
To adjust, loosen compressor bracket and adjusting Radiator coo/ant level checked Yes No
screws.
Coolant or anti-freeze added, if any -qts. (L)
Alternator be/t tension -Ibs. (N) (kg) tension
inch (mm) flex
Fan belt tension -Ibs. (N) (kg) tension
-inch (mm) flex
Compressor belt tension -/bs. (N) (kg) tension
-inch (mm) flex

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozer
IV-24 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

10. Fuel Tank Sump 11. Track Sag Adjustment

Fig. 64Fuel Tank Sump

Fig. 65-Measuring Track Sag
Open drain cock (A) located at bottom of fuel tank.
Drain fuel until all sediment drains out. Close and tighten Measure amount of sag in center of track between
drain cock. carrier roller and front idler. Sag should be 1 to l-1/2
inches (25.4 to 38 mm).
NOTE: Drain sump after era wler has been shut down
for at least 2 hours. NOTE: A pin and bushing must be lined up over the
carrier roller.
Fuel tank sump drained Yes No
Filter checked Yes No

753058

A- -Grease Fitting C-Vent Hole

B- Check Valve

Fig. 66-Adjusting Track Tension

Loosen screw and open access cover.

bitho in U.S.A.
 JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Predelivery, Delivery, and After-Sale Services IV-25

INWARD-
To increase track tension:
1 - Attach a grease gun (8000 psi [552 bar] [562 kg/
cm21 max.) to the grease fitting (A) on the track
adjuster.
2 - Apply grease until the proper track tension is
achieved.

To decrease track tension:

1 - Turn check valve (6) 1 to 3 turns counterclockwise.
This will allow grease to escape through the vent
hole (C).
2 - Turn check valve clockwise to close valve.

A
CAUTION: High pressure may be present in
the track adjuster cylinder. If grease does not
immediately escape from the vent hole, drive the unit
forward and backward slowly, then tighten check
valve. A-Inner Guide D-Wear Stip
B-Wear Strip E-Wear Strip
IMPORTANT: Never lubricate fitting on hydraulic C-Outer Guid F-Wear Strip
track adjusting cylinder except when track is in need
Fig. 69-Track Wear Shim Aaptments
of adjustment.
Slide the front idler inward. If inner guide (A, Fig. 69)
does not contact inward side of wear strip(B), additional
shims must be added. To add shims, remove outer
guide (C). Add shims as required until outer guide con-
tacts outward edge of wear strip (D) at the same time
that the inner guide (A) contacts the inward side of wear
strip(B). Replace and tighten cap screws on outer guide
(Cl.

The same procedure applies when checking shim ad-

justment on the opposite side of the front idler. Repeat
both procedures for checking front idler horizontal ad-
justment on opposite side of the crawler.

Loosen the two cap screws on the top of inner guide

(A). Pry inner guide up between the inner guide and
block. If inner guide (A) is free to move up, additional
shims must be added. Remove the two cap screws and
add vertical adjustment shims as required. When shim-
ming is completed, there should be .OOto .04 (1 mm)
maximum gap vertical movement between inner guide
Fig. 67 and 68-Track Wear Check (A) and block.
IMPORTANT: When the forward edge of the front
idler block (C) is approximately in line with the front The previous adjustment has eliminated the clear-
edge of the top wear strip (D), the track adjuster stop ance between the wear strip on the inner guide (A) and
(A) will contact the track frame (B) and no further the wear strip (F) on the track frame.
increase in track tension can be obtained. To avoid
damage, recondition track. Replace and tighten cap screws on inner guide (A).

The same procedure applies when checking the shim

adjustment on the opposite side of the front idler. Re-
peat both procedures for checking front idler vertical
adjustment on opposite side of the crawler.

Litho in U.S.A.
 I General lnforma tion JD750 Crawler Bulldozer
IV-26 Predelivety, Delivery, and After-Sale Services TM- 1136 (Mar-84)

12. Track shoe Cap Screws

Fig. 70-Movable Carrier Roller Front Support

The carrier roller front support is movable to compen-

sate for uneven track wear. To adjust, remove the four
cap screws and the support and add or delete shims (in
pairs), as required, until center of track is aligned with
center of carrier roller. Tighten cap screws to idler sup
port.

IMPORTANT: Do not adjust the carrier roller front

support until all of the track tension and shim adjust-
ments have been completed.

Track tension checked Yes No

Front idler and carrier roller wear checked Yes No
Adjustment required Yes No Fig. 71-Track Shoe Cap Screw

Tighten all cap screws to 550-600 lb-ft (746-813

Nam).

Cap screws tightened Yes No

Litho in U.S.A.
 JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Predelivety, Delivery and After-Sale Services IV-27

13. Lubrication
Check each lubrication point shown on the following
pages. Lubricate with several strokes of John Deere
Multi-Purpose Grease or equivalent, if necessary.

Fig. 74-Pitch Adjusting Jack and Socket

(Dozer Blade) (2 points)

Lubricant required Yes No

Fig. 72-Dozer Lift Cylinder Yokes and Trunnions
(6 points)

Lubricant required Yes No

Fig. 75Tilt Adjusting Jacks

(Angle Dozer Blade) (4 points)

Lubricant required Yes No

Fig. 73Crossmember (Low Ground Pressure)

Crossmember grease fittings (A) for Low Ground

Pressure machines are serviced through the grille.

Lubricant required Yes No

Litho in U.S.A.
I General In formation JO750 Crawler Bulldozer
IV-28 Predelivery, Delivery, and After-Sale Services TM- 1136 (Mar-84)

fig. 76-Universal Joints (4 points)

Lubricant required Yes No

fig. 78-Left and R@ht Track

Frame Pivots (2 points)

Remove plug. If fluid level is low, fill to topof shaft with

a multi-Purpose GL-5 Gear Oil - SAE 8OW-90 weight
meeting MIL-L-2105C specifications or an equivalent.
Replace plug.

Left and right track

frame pivots checked Yes No

Oil added Yes No

14. Cab Air Filter

Fig. 77-Left and Right Track Frame Pivot Shaft
(2 points)

Lubricant required Yes No

Fig. 77-Cab Air filter

Clean and replace air filter.

Cab air filter cleaned Yes No

bitho in U.S.A.
 JD 750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Predelivety, Delivery, and After-Sale Services IV-29

15. Batteries Normal operating range is in the light green zone.

Check transmission oil pressure gauge during oper-

ation. If transmission oil pressure is not in the light green
zone, shut off engine. Check transmission oil level. If oil
is at proper level, troubleshoot the transmission system,
checking for bent or broken lines and hoses. Also check
for excessive leakage.

Transmission oil pressure may register slightly above

the green zone in neutral or at full engine speed.

Fig. 80-Batteries

Check battery electrolyte level. If distilled water is not

available, use clean soft water. Avoid use of hard water.
Remove foreign material from top of battery and coat
terminals with petroleum jelly.

IMPORTANT: Never add water to battery in freez-

ing weather unless engine is to be run 2 or 3 hours to
assure mixing of water and electrolyte.
Fig. 82-Engine Oil Pressure Gauge
Check battery connections.
If the indicator hand of the engine oil pressure gauge
Water added Yes No drops into the red-orange zone, stop the crawler and
Batteries checked check engine oil level. If oil level is not low, check for
and serviced Yes No restrictions in oil lines or incorrect viscosity oil.

16. Indicator Lights and Gauges

LIGHT GREEN
When operating the crawler, check the following
gauges for correct operation.

NGE
ORANGE

LIGHT
RED GREEN
ORANGE

T43408 743408

Fig. 83-Voltmeter

With key switch on and engine off, the indicator

should be in the lower left light green zone.

When cranking the engine, the indicator will fall into

i-43407
143407 the left-hand orange zone. When the engine starts, the
Fig. B&Transmission Oil Pressure Gauge indicator should move to stay in the right-hand light
green zone.

Litho in U.S.A.
I General Information JD750 Crawler Bulldozer
IV-30 Predelivery, Delivery, and After-Sale S&vices TM- 1136 (Mar-84)

(66%) (93%) The transmission oil filter indicator light glows red
15OOF /2OOOF
also if the pressure switch located with the engine oil
pressure unit is faulty, if the engine oil pressure is low, or
LIGHT GREEN
ZONE if the oil is cold during intial startup.

(52oC)
125°F

Fig. 87-Hydraulic Oil Filter

T43.m
Restriction Indicator Light
Fig. 84-Transmission Oil Temperature Gauge

Do not permit this temperature to exceed 2OO’F NOTE: Light should glow, if operative, with key
(93OC). If the temperature reaches this point during op switch in star? position and engine off.
eration, stop the engine and locate the trouble.
When the engine is running, the hydraulic oil filter
indicator light should go out. If light glows red while the
engine is running, stop engine and determine cause.

Light may glow during initial operation until oil warms.

17. Charging System

With key switch on and engine off, the indicator on the
voltmeter should be in the lower left light green zone.

When cranking the engine, the indicator will fall into

Fig.85-Engine Water Temperature Gauge
the left-hand orange zone. When the engine starts the
Normal operating temperature is in the light green indicator should move to and stay in the right-hand light
zone. green zone.

If the indicator hand of the engine water temperature If the above conditions are met, the system is in prop-
gauge goes into the red-orange zone, check cooling er working order.
system.
Charging system operational Yes No

&mmmm

T.231111 I cl b

Fig. 86-Transmission 011 Filter

Indicator Light

NOTE: Light should glow, if operative, with key

switch in start position and engine off.

When the engine is running, the transmission oil filter

light should go out, indicating that there is no restriction
in the transmission and oil filters. If light glows red while
the engine is running, stop engine and determine cause.

Litho in U.S.A.
JD750 Crawler Bulldozer General Information I
TM- 1136 (Mar-84) Predelivery, Delivery, and After-Sale Services IV-31

18. Hydraulic Brake (Park Brake)

T57010NY

A-Brake Lever D-Locking Nut

B-Brake Valve Plunger E-Bulkhead Cable Fittings
C-Ball Joint F-Cable Support
A-Park Brake Pedal B-Park Brake Lock Knob
fig. ES-Brake Valve Linkage Adjustment

Fig. &?&Parking Brake 1 - Depress brake pedal against the pedal stop. The
,’
Depress brake pedal and pull lot knob up. Release brake valve plunger (B, Fig. 89) should bottom
brake pedal; brakes will lock in the desired position. out at the same time or just before the brake
pedal bottoms out. In no case should the cable
To disengage park brake, step on pedal. be heavily loaded by applying the brake pedal.
2 - If it does not bottom out completely or bottoms
If park brake does not stop machine, adjust as fol- out too soon, loosen locking nut (D).
lows: 3 - Unhook ball joint (C) from brake lever (A).
4 - Turn ball joint until it will hold the brake lever in far
enough so that the brake valve spool bottoms
out at the same time as the brake pedal or just
before.
5 - Hook ball joint to brake lever.
6 - Tighten locking nut.
7 - If additional adjustment is required, adjust bulk-
head cable fittings (E) on cable support (F).
8 - With the brake pedal in the latched position,
check that the brakes are fully applied.

Park brake checked Yes No

Adjustment required Yes No

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozer
IV-32 Predelivety, Delivery, and After-Sale Services TM- 1136 (Mar-84)

19. Fluid Leakage

Check the following systems for leakage due to poor
or faulty connections and broken hoses or lines.

A. Cooling system
checked OK Yes No
B. Hydraulic system
checked OK Yes No
C. Transmission. system
checked OK Yes No
D. Fuel system checked
OK Yes No
E. Steering system
checked OK Yes No
F. Track frame pivots
checked OK Yes No

If answer to any of the above is no, please explain.

Litho in U.S.A.
 JD750 Crawler Bulldozer General information
TM-1 136 (Nov-75) Predelivery, Delivery and After-Sale Services

IMPORTANT: Do not adjust the upper idler front Review the following lube points with the customer
support until all of the track tension and shim and record any that were not lubed.
adjustments have been completed.
Lubrication comments:
Track aligned Yes No

14. Track Shoe Cap Screws

Apply several shots of John Deere Multi-Purpose

Lubricant or an equivalent grease to the pivot points
shown in the following illustrations that require lubing.

Wipe dirt from fittings before greasing. Replace

damaged or lost grease fittings immediately.

fig. 57-Track Shoe Cap Screws

Y

Tighten all cap screws to 280 lb-ft (380 Nm) (39

kg/m) minimum.

.1 Cap screws tightened Yes No

15. Check All Grease Fittings

Check all grease fittings for proper lubrication.
Grease any fittings that appear neglected.

Impress upon the owner the importance of periodic

greasing as outlined in the operator’s manual.

Fig. 584niversal Joints (Left Shown)

Grease fittings iubricated Yes No

Litho in U.S.A.
 General Information JD750 Crawler Bulldozer
Predelivery, Delivery, and After-Sale Services TM- 1136 (Nov-75)

Fig. 67-Left and Right Track Frame Pivot Shaft

Grease fittings lubricated Yes No

Fig. 59-Pitch Adjusting Jack and Socket (Manual Tilt)

16. Cab Air Filter (If equipped)
Grease fittings lubricated Yes No

Fig. 62-Cab Air Filter

Clean air filter.

Fig. 60-Dozer Lift Cylinder Yokes and Trunnions
Cab air filter cleaned Yes No
Grease fittings lubricated Yes No

Litho in U.S.A.
JD 750 Crawler Bulldozer General Information I I
TM- 1136 (Nov-75) Predelivery, Delivery, and After-Sale Services IV-35

17. Batteries 19. Charging System L

With the key switch on and the engine off, the

indicator on the voltmeter should be in the lower left
light green zone.

When cranking the engine, the indicator will fall into

the left-hand orange zone. When the engine starts the . -. r
indicator should move to and stay in the right-hand
light green zone.

If the above conditions are met, the system can be

considered to be in proper working condition.

Charging system operational Yes No

Fig. 63-Batteries
20. Parking Brake
The batteries are located directly underneath the
operator’s seat. Raise hinged seat cushion to gain
access to batteries.

A CAUTION: Gas from electrolyte is flam-

mable. Keep batteries away from sparks or
fires.

Check battery electrolyte level. If distilled water is

not available, use clean soft water. Avoid use of hard
water. Remove foreign material from top of battery and
coat terminals with petroleum jelly. Clear vent holes in
battery caps.

Water added Yes No

A-Park Brake Pedal B-Park Brake Lock Knob

Baneries checked
and serviced Yes No
Fig. 64-Parking Brake

18. Gauge Operation

Check the parking brake for correct adjustment.
When operating the bulldozer, check all gauges to
see if they are operational and indicator hands are Depress brake pedal and pull lever up. Release
responsive. brake pedal; brakes will be locked in the desired posi-
tion.
Gauges operational Yes No

To disengage park brake, step on pedal.

If no, explain malfunction

Parking brake operational Yes No

Litho in U.S.A.
 I General Information JD750 Crawler Bulldozer
IV-36 Predelivery, Delivery, and After-Sale Services TM- 1136 (Nov-75)

21. Fluid Leakage

Check the following systems for leakage due to poor
or faulty connections and broken hoses or lines.
:

A. Cooling system
checked OK Yes No
B. Hydraulic system

q checked OK
C. Transmission system
checked OK
Yes

Yes
No

No
D. Fuel system checked
OK Yes No
E. Steering system
checked OK Yes No
F. Track frame pivots
checked OK Yes No

If answer to any of the above is no, please explain.

Litho in U.S.A.
 JD750 Crawler Bulldozer General information I
TM- 1136 (Mar-84) Lubrication V-l

Group V
FUELS AND LUBRICANTS
GENERAL INFORMATION
Illustrated below is a periodic service chart mounted on the outside of the left console (without cab) or outside the
left side of the cab. More detailed information on servicing the crawler can be found in the current operator’s manual.

Use the operator’s manual and periodic service chart as references when servicing the crawler. Remind your
customer to thoroughly read the operator’s manual before attempting to service or operate the crawler.

T94323

fig. l-Periodic Service Chart

Litho in U.S.A.
I General lnforma tion JD750 Crawler Bulldozer
V-2 Fuels and Lubricants TM- 1136 (Mar-84)

FUELS Filling the Fuel lank

Fuel Specifications
Use ONLY clean, high-quality fuel.

Use Grade No. 2-D fuel above 40°F (4OC).

Grade No. 1-D fuel at temperatures below 40°F

(4°C). Use Grade1 -D for all air temperatures at altitudes
above 5000 ft. (1 500 m). :.
f58993Y

Fig. Z-Fuel Tank Filler Cap

IMPORTANT: If fuel sulfur content exceeds 0.5
percent, the engine oil drain interval must be re- The fuel tank is located at the rear of the crawler
duced by 50 percent (to 100 hours). bulldozer.

Use fuel having less than 1.0 per cent sulfur. If Fill fuel tank at end of each day’s operation.
possible, use fuel with less than 0.5 per cent sulfur.
Fuel tank capacity is 73 U.S. gal. (276.3 L).
For maximum filter life, sediment and water should
not be more than 0.10 per cent. To help keep water out of fuel system, drain the fuel
tank for several seconds every 200 hours.
The cetane number should be 40 minimum. If you

A fuel tank when the engine is running. Do not

operate your crawler bulldozer where air temperatures CAUTION: Handle fuel carefully. Do not fill
are normally low or where altitudes are high, you may
need fuel with a higher cetane number. smoke while you fill fuel tank or work on fuel system.

Cloud Point - For cold weather operation, cloud point LUBRICANTS

should be 10°F (6OC) below lowest normal air tempera-
ture. Storing Lubricants
Your crawler can operate at top efficiency only if clean
Storing Fuels lubricants are used. Use clean containers to handle all
NOTE: Diesel fuels stored for a long time may form lubricants. Store them in an area protected from dust,
gum and plug filters. moisture, and other contamination.

Keep fuel in a container in a protected area. Water Effective use of lubricating oils and greases is per-
and sediment must be removed before fuel gets to the haps the most important step toward low upkeep cost,
engine. Do not use de-icers to remove water from fuel. long crawler life, and satisfactory service. Use only lubri-
Do not depend on fuel filters to remove water. cants specified in this section, apply them at intervals
and according to the instructions in the lubrication and
If possible, install a water separator at the storage periodic service section.
tank outlet.

Store fuel drums on their sides with plugs up.

IMPORTANT: Keep all dirt, scale, water, and other

foreignmatter out of fuel.

Litho in U.S.A.
 JO750 Crawler Bulldozer General lnforrna tion
TM- 1136 (Mar-84) Fuels and Lubricants

Engine Oil
AIR TEMPERATURE RANGE

1 I
I ’I I I I ,
SAE 30
1
I iI II I I I
SAE 15W40

I I SAE 15W30
I , 1
I
SAE 1OW
I

I I
SAE SW20
I I
ARCTIC OIL

Depending on the expected air temperature range Oil Specification Use

between oil changes, use oil viscosity shown on the
temperature chart above. API Service CD/SC Recommended
(MIL-L-2104C)
Additives are not required nor recommended.
API Service CC/SC* For SAE 5W20, SAE 5W30
John Deere TORQ-GARD SUPREME@ engine oil is or MIL-L-461520 and arctic oil only, use if rec-
recommended. If other oils are used, they must have the ommended oil is not avail-
following minimum specifications. able

MIL-L-46167. For arctic oil only

l Change oil at 100 hours, which is half the normal drain

interval.

Transmission Oil
Use:

John Deere All-Weather Hydrostatic Fluid

Oils meeting John Deere Standard JDM J21A

Litho in U.S.A.
I General Information JD750 Crawler Bulldozer
v-4 Fuels and Lubricants TM- 1136 (Mar-84)

Hydraulic System Oil

AIR TEMPERATURE RANGE

Fahrenheit (“F) -67 -40 -22 -4 14 32 50 66 66 104 122

Celsius (oc) -55 -40 -cjo -20 -10 0 10 20 30 40 50

I I I I I. I

I I

I I I I I I

I I

I I I
I
I

I I

Depending on the expected air temperature range

between oil changes, use oil viscosity shown on the
temperature chart above.

The following oils are recommended:

John Deere HY-GARD@ Transmission and Hy-

draulic Oils

Engine oil meeting API Service CD/SC (MIL-L-

2104C), CC/SC, or MIL-L-46152.

You may also use QUATROL@ oils, which are oils that
meet John Deere standards, or other oils meeting John
Deere Standard J20A or J2OB.

Oil meeting MIL-L-46167 may be used as an arctic oil.

Litho in U.S.A.
JD750 Crawler Bulldozer General lnforma tion I
TM- 1136 (Mar-84) Fuels and Lubricants v-5

Final Drive Oil

AIR TEMPERATURE. RANGE

Fahrenheit (“F) -67 -40 -22 -4 14 32 50 66 66 104 122

II - I
Celsius (“c) -55 -40 -30 -20 -10 0 10 20 30 40 50

iI iI iI
I I

I
I
I
I I I
I I ,I

I I I I I I I

I
I I I I I I

I I
I I I I
I .
I I
.

Tea972

Depending on the expected air temperature range

between oil changes, use oil viscosity shown on the
chart above.

The following oils are recommended:

John Deere API GL-5 Gear Oil

Oils meeting API Service GL-5 (MIL-L-2105B or

MIL-210%)

Oil meeting MIL-L-10324A may be used as arctic oil.

Splitter Drive Oil

Use SAE 30 engine oil meeting API Service CD/SC
(MIL-L-2104C), CC/SC, or MIL-L-46152.

Track Roller, Front Idler, and Carrier Roller

Oil
Use SAE 8OW90 gear oil meeting API Service GL-5
(MIL-L-21058 or MIL-L-2105C).

Litho in U.S.A.
 I General Information JD750 Crawler Bulldozer
V-6 Fuels and Lubricants TM- 1136 (Mar-84)

Grease
AIR TEMPERATURE RANGE

JOHN DEERE HIGH TEMP./EP

ARCTIC GREASE

Depending on the expected air temperature range during use, use grease shown on chart above.

Greases recommended are:

SAE Multipurpose Grease with Extreme Pressure (EP) performance and containing 3 to 5 per cent molybdenum
disulfide (preferred)

John Deere High Temperature/EP Grease

SAE multi-purpose EP grease

Grease meeting MIL-G-10924C specifications may be used as arctic grease.

Cold Weather Opertion

Additional information on cold weather operation is available from your Region office.

Alternative Lubricants

Conditions in certain geographical areas may require special lubricants and lubrication practices which do not
appear in this manual. If you have any questions, consult your Region office to obtain the latest information and
recommendations.

Litho in U.S.A.
JD 750 Crawler Bulldozer Tracks 1
TM- 7 136 (Mar-84) Track Systems 0130-l

Section 1
TRACKS
CONTENTS OF THIS SECTION
,J
Page GROUP 0130 - TRACK SYSTEMS (Continued)
GROUP 0130 - TRACK SYSTEMS Drive Sprockets, Chains and Shoes
Track Frames General Information ................ 0130-26
General information ................. 0130-3 Drive Sprocket
Removal ......................... .0130-4 Removal. ..................... .0130-26
Repair ........................... 0130-6 Installation ..................... 0130-26
installation ........................ 0130-8 Measure Sprocket Wear ........ .0130-26A
Replacing Track Frame Track Shoes
Wear Strips ...................... .0130-g Measure Track Shoe Wear ...... .0130-268
Front Crossbar Removal ..................... .0130-268
Removal ........................ .0130-11 Repair ...................... .0130-268
Installation ....................... 0130-l 2 Installation ................... .0130-268
Rollers, Idlers and Recoil Spring Sealed Track Chain
General Information ................ 0130-l 3 Measure Link Height ........... .0130-26D
Track Rollers Measure Bushing Outside
Measure Track Roller Wear. ....... 0130-l 3 Diameter .................. .0136-26D
Removal ...................... .0130-l 3 Measure Track Pitch ............ .0130-27
Repair ....................... .0130-l 3 Removal. ..................... .0130-28
Installation ..................... 0130-l 5 Repair ....................... .0130-29
Carrier Rollers Rotating Pins and Bushings ....... 0130-33
Measure Carrier Roller Wear ..... .0130-156 Installation ..................... 0130-34
Removal ...................... .0130-l 6 Recoil Spring and Hydraulic Track
Repair ....................... .0130-l 6 Tension Adjuster (Low Ground
Installation ..................... 0130-l 7 Pressure Bulldozer)
Front Idler Remove ........................ .0130-35
Measuring’ Front Idler Wear. ....... 0130-l 8 Disassemble. .................... .0130-37
Removal ...................... .0130-l 8 Assemble ....................... .0130-37
Repair ....................... .0130-l 8 Install ........................... 0130-38
Installation ..................... 0130-21
Track Adjuster and
Recoil Spring
Removal ...................... .0130-23
Repair ....................... .0130-23
Installation ..................... 0130-25

Litho in U.S.A.
1 Tracks JD750 Crawler Bulldozer
0130-2 Track Sys terns TM- 1136 (Mar-84)

GROUP 0130 - TRACK SYSTEMS (Continued) GROUP 0199 - SPECIFICATIONS AND

Lubricated Track Chain SPECIAL TOOLS
Measure Link Height . . . . . . ~ . . . . . . . 0130-40 Specifications and Torque Values ~ . . . . . . 0199-l
Measure Bushing Outside Special Tools.. . . . . . . . . . ~. . ~. ~. . . . . . 0199-11
Diameter . . . . . . . . . . . . . . . . . . . . . . 0130-40
Measure Track Pitch . . . . . . . . . . . 0130-41
Remove . . . . . . . . . . . . . . . . . . . . . . . . 0130-42
Disassemble
To Turn Bushings and
Relubricate . . . . . . . . . . . . . . . . . . 0130-43
To Turn Pins and Bushings and
Not Relubricate . _ . _ . . . I . . . . 0130-55
To Repair a Dry Joint or
Broken Link and Relubricate . . . . . 0130-62
Assemble
To Turn Bushings and
Relubricate. . . . . . . . . . . . . . . . . . . 0130-46
To Turn Pins and Bushings and
Not Relubricate . . . . . . . . . . . . . . . 0130-58
To Repair a Dry Joint or
Broken Link and Relubricate . . . . . 0130-65
Install . . . . . . . . . . . . . . . . . . . . . . . . . 0130-70

Litho in U.S.A.
 JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Track Sys terns 0130-3

Group 0130
TRACK SYSTEMS
TRACK FRAMES
GENERAL INFORMATION

l-Drive Sprocket 5-Front Idler &Double Flange Track Roller

2-Upper Idler (2 used) 6-Dozer Blade (2nd, 3rd and 5th roller)
3-Spring Cover I--Rock Guard g-Single Flange Track Roller
Aaster Pin (lst, 4th and 6th roller)
16-Track Frame

Fig. l-Track Frame Assembly

The track frame assembly is mounted on a cross-. The pivot shaft allows the track assembly to pivot at
bar at the front and on a pivot shaft at the rear to the rear attaching point.
give a fixed tread of 74 inches (188 cm).
750 Bulldozer has six track rollers on each side to
The front crossbar is a tapered single-leaf spring support the load of the crawler. The first, fourth and
crossbar providing 10 inches (254 mm) oscillation at sixth rollers are single flanged. The second, third, and
front idler centerline. fifth rollers are double flanged.

750 Low Ground Pressure Bulldozer has seven track

rollers, spaced irregularly. Single and double flanged
rollers are used alternately, beginning and ending with a
single flanged roller.

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-4 Track Sys terns TM- 1136 (Mar-84)

REMOVAL Release track tension by turning the check valve (2,

Fig. 2) one to three turns counterclockwise, which will
NOTE: The following chain removal procedure is for
allow grease to escape through the vent hole (3).
750 Bulldozer or 750 Low Ground Pressure Bulldozer
with sealed track chain. For units with lubricated track
Remove track shoe above the master pin.
chain, see Remove Lubricated Track Chain in this
group.
Use a D01030AA Master Pin Pusher or other suit-
able tool and press master pin from track links (Fig. 2A).
The folio wing track ao@s ter removal and spring co*
pression procedures are for 750 Bulldozer units. For
750 Low Ground Pressure Bulldozer units, see Remove
L
,. Recoil Spring and Hydraulic Track Tension Adjuster
(Low Ground Pressure Bulldozer) in this group.

NOTE: A-frame bearing (1, Fig. 4) may be serviced

by removing pivot shaft inner mounting bracket and cap
screws securing track frame to A-frame bearing. Re-
move A-frame bearing from pivot shaft.

Refer to page 1-0130-g to replace track frame wear

strips (1 and 2, Fig. 5). Track frame does not have to be
removed from crawler.

Raise the rear of the crawler using a floor jack of at

l-Grease Fitting 3-Vent Hole
least 10 ton (89 000 N) (9 100 kg) capacity and block it
l--Check Valve
up securely.
fig. Z-Adjusting Track Tension

A
CAUTION: Do not work around crawler with-
out securely blocking it up.

Use the dozer blade to raise the front of the crawler

and slide blocks under the front of the main frame.

Refer to Section 32, Group 3240 and remove dozer

frame.

A
CAUTION: Make sure both tracks are clear of
the floor before rotating track.

Start engine and rotate track until master pin is on the

front idler about 6 inches (152 mm) from the floor.

Fig. 2A-Pressing Out Master Pin

A
CAUTION: Headless master pins are made of
extremely hard material. Do not try to drive out
master pins with a hammer. Hard material can chip
and cause serious personal injury and damage to
parts.

Litho in U.S.A.
JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Apr- 79) Track Systems 0130-5

l-Right-Hand A-Frame g--Track Adjuster

Bearing stop
a-Track Adjuster 7-Holddown Plate
l-Track Adjuster 4-Deflector
Housing S-Cap Screws
Head g--Right-Hand Block
&Track Adjuster g-Recoil Spring
P-Front Idler Yoke 6-Gap Screws
Cylinder ltI-Spring Adapter
Z&Front Idler
Cylinder Retainer 1 l-Cap Screws
Assembly
!i-Track Adjuster 12-Pivot Shaft
Head Bracket Cap
Fig. 3-Removing Front idler
12-Plug

Move track assembly clear of crawler. Fig. 4-Remove Track Adjuster Assembly

Remove cap screws, special nuts and spring cover Install JD-314 Track Spring Compressor through
from track frame. track adjuster housing and thread into spring adapter.

Remove deflectors (4, Fig. 3) from front idler yoke NOTE: Grease contact area between head of bolt 1
(2). and adapter plate.

Remove cap screws (6) securing front idler yoke to .Tighten bolt approximately 314 inches (19 mm) or j
left-hand and right-hand block (5). until spring adapter (10) on recoil spring (9) is free.

Slide front idler (3) forward and remove from track Remove cap screws (8) and holddown plates (7). Lift
frame. spring from track frame.

Remove cap screw securing front idler yoke (2, Fig.

3) to right and left blocks. Remove front idler yoke. A CAUTION: Use care when handling spring
as accidental release of spring can cause
serious personal injury. Do not, under any circum-
Remove cap screws securing track adjuster head (5, stances, attempt to remove spring without special
Fig. 4) to cylinder retainer (4). Remove track adjuster tools.
stop (6) and slide track adjuster head as far forward as
possible. NOTE: Do not remove special tool from recoil
spring unless the spring requires service. Refer to
Remove track adjuster cylinder (3), piston, spacer page l-0130-22 to service and preload the spring. 1
and cylinder retainer (4) from track adjuster housing
(2). Remove carrier rollers from track frame.

Remove cap screws (1 l), pivot shaft bracket cap

(12) and retainers.

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-6 Track Systems TM- 1136 (Apr- 79)

A CAUTION: Make sure crawler is securely

blocked under transverse case and front
Remove pivot shaft
housing and transverse
assembly
case.
from final drive

main frame.
Due to welded construction of track frame, no fur-
Remove cap screws securing A-frame bearing (1, ther disassembly of the track frame should be at-
Fig. 4) to track frame. tempted. The track channel and inner guide wear
strips can be replaced if worn (page 1-0130-g).
Slide track frame assembly free from front cross-
bar and rear pivot shaft.

Remove rock guards and track rollers from track

frame.

REPAIR

RIGHT A-FRAME BEARING

l-upper Wear Strip (2 uued) 7-c8p sc+w (4 lmed) m-cap &row (4 wed)
2-Lower Wear Strip (2 used) B-Right-Hand Rock Guard (early) 14-gpeclal Washer (4 used)
3-Track Frame g-cap screw (10 used) 1Lt (5 used)
e-cap screw (4 used) lo-Nut (5 used) M-pipe plug
ib5pedal Washer(18 used) ll-Lock Washer (5 used) 17-S3al
Cft+land Rock Guard (early) 12-qmw (5 wed) IS-Buahlng
19--8urhlng

f&. S-Track Frame and Rock Guards

Litho in U.S.A.
 JD 750 Crawler Bulldozer Tracks 1
-W--1-36 (Mar-841 Track Sys terns -613b-7

Refer to Figs. 5, 6 and 7 for position of parts during

disassembly and assembly.

IMPORTANT: Operating unit with loose pivot shaft

bolts (R, Fig. 7) can cause the pivot bracket and final
drive housing mating surfaces damage.

Inspect dowel pin (F). If dowel pin needs to be re-

placed, machine mating surfaces flat before replacing
dowel pin. \
\
Inspect all parts for wear, cracks or other damage.
-- Replace parts if necessary.
5”622O?N
T62207N Press bushing (M, Fig. 7) flush with outer surface of
l-Bolt (6 used) E-Spacer (6 used) bushing bore in A-frame bearing (N).
2-L.H. Track Guide S-Cap Screw (12 used)
3-Cap Screw (6 used) lo-R.H. Rock Guard Install oil seals (L), with free end of lip to outside of
4-Washer (20 used) 11-Washer (2 used) bore in A-frame bearing.
S-L.H. Rock Guard 12-Washer (6 used)
6-R.H. Rock Guard 13-Nut (6 used) Install oil seal cup (P) with flat side to contact bottom
7-Cap Screw (4 used) of bore in A-frame bearing.

Fig. 6-Rock Guards and Track Guides (late)

A-Cap Screw (4 used) H-Shim M-Bushing

B-Washer (4 used) I -Pivot Shaft Inner N-A-Frame Bearing
C-Pivot Shaft Bracket Cap Mounting Bracket O-Oil Seal (2 used)
D-Retainer (2 used) J-Special Washer P-Pivot Shaft Seal Cup
r
E-Seal (8 used) Q-Pin
F-Dowel Pin K-Bolt (4 used) R-Bolt (4 used)
G-Pivot Shaft L-Oil Seal (2 used) S-Bolt (4 used)

Fig. 7-Pivot Shafi Assembly

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-8 Track S ysterns TM- 1136 (Mar-83

INSTALLATION Install holddown plates (7, Fig. 4) to track frame. Posi-

tion two washers between holddown plate and track
Install track rollers with oil ports to the outside.
frame and one washer under cap screw head.
For 750 Bulldozer, install single flanged track rollers in

A
the first, fourth and sixth positions and double flanged CAUTION: Do not release load on recoil
track rollers in the second, third and fifth positions, spring until it is installed in track frame and
counting from front of unit. For 750 Low Ground Pres- secured in position with holddown plates. Accidental
sure Bulldozer, install single and double flanged track release of recoil spring can cause serious personal
rollers alternately, beginning and ending with a single injury.
flanged roller. Install and tighten D-grade, cap screws to
170 lb-ft (230 N.m) and F-grade cap screws to 192- Position track adjuster assembly in track adjuster
288 lb-ft (260-391 N.m). housing.

Secure track adjuster head to cylinder retainer. Posi-

tion track adjuster stop to the bottom two holes.

Install front idler yoke to track adjuster head. Install

and tighten cap screw to 340-510 lb-ft (461-691
Nam). Rap head of cap screw with a 5 lb. (2 kg) hammer
and retighten to 340-510 lb-ft (461-691 N.m). _

Install the right front idler with the oil fill plug facing
outside of unit. Install the left front idler with the oil fill
plug toward inside of unit. Secure with cap screws (6,
Fig. 3) and tighten cap screws to 300 lb-ft (407 Nem).

A-Cap Screw Install deflectors (4), spring cover and sprocket.

Fig. 7A-Pivot Shaft Cap Screw Tightening Procedure
Install rock guards, track guides, and sprocket
Assemble pivot shaft to final drive housing. Lubricate shields. Apply John Deere Loctite Thread Lock and Sea-
threads and bearing surface of pivot shaft cap screws lant High Strength or an equivalent to rock guard and
with oil. Install and tighten cap screws using a cross track guide to track frame cap screws. Install bolts (15,
pattern, beginning with top outside cap screw (A, Fig. Fig. 5 or 1, Fig. 6) with nuts to the outside. Tighten nuts
7A). Tighten cap screws to 200 f 20 lb-ft (271 + 27 (10, Fig. 5 or 13, Fig. 6) to 300 lb-ft (407 N-m).
N.m) plus an additional 90’ turn.

Install A-frame bearing assembly (L-P, Fig. 7) on pivot Position tracks on crawler. Using a master pin pusher,
shaft. install master pin, spacers and seals.

Position inner mounting bracket (I) on pivot shaft. Remove plug (13, Fig. 4) and fill track frame pivot
Install shims (H) between transverse case and bracket shaft bracket with 16 ounces (473 ml) of oil as recom-
to fill gap. Secure bracket to transverse case with bolts mended in Section I, Group V. Oil level must be at least
(to. to top of pivot shaft.
Install seal (E) in bore in pivot shaft bracket on track
frame. Position seal so that flat side of seal faces out. Refer to Group 9030 and adjust track tension, front
carrier roller alignment and front idler guide adjustment.
Install track frame on pivot shaft and front crossbar.

Install cap screws (13, Fig. 5) securing track frame to

A-frame bearing. Do not tighten cap screws at this time.

Install retainers (D, Fig. 7) and pivot shaft bracket cap.

Tighten cap screws (13, Fig. 5).

Position preloaded recoil spring in track frame. Make

sure top of spring is parallel to track frame and track
adjuster housing is positioned as shown in Fig. 4.

Ifitho in U.S.A.
JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Track Systems 0130-g

Replacing Track Frame Wear Strips When putting on new wear strips, do not clamp wear
strips firmly to track frame. A secure clamping which still
Inspect front idler wear strips on track frame for wear.
allows a slight wear strip shift will prevent cracking of
If strips are excessively worn, replace according to the
weld fillet during the cooling process.
following procedure.

Weld the lower wear strips (1, Fig. 8) to track frame

Refer to page l-0130-4 and remove the track and
(2), melting as little as possible of the wear strips by
front idler assembly.
starting and maintaining the arc primarily on the track
frame. The wear strip is a high carbon steel so best
Grind off the old wear strips on the track frame chan-
results are obtained by washing the weld metal toward
nel so that none of the strips or welds remain.
the wear strip. This will produce a slightly convex weld
fillet.
Install new wear strips.

NOTE: The wide wear strips fit on top of the track

channel. The narrow strips fit underneath.

Recommended Welding Procedure

IMPORTANT: Disconnect battery ground strap or
turn off battery disconnect switch before doing any
welding on the crawler. Failure to do so may damage
the electrical system.

Recoil springs are extremely vulnerable to any-

thing which will cause a stress concentration result- T43973N
ing in a weak spot. A crater or even a small nick can 743973N
l-Lower Wear Strip l-Track Frame
be enough to cause a weak spot, which may result in
(2 used)
spring failure.
Fig. &We/dingLower Wear Strip
When welding near a recoil spring be careful not to
strike an arc on spring or use it as a ground connec- Weld lower wear strip (1, Fig. 8) to track frame using
tion which can result in a crater in spring surface. l/4 inch (6.4 mm) fillet weld on the ends and 3/16 inch
Always cover spring with some heavy protective ma- (4.8 mm) plug welds in the three holes. Grind the weld
terial to protect it from weld splatter. areas even with wear strip.

1. Remove dirt, oil and paint from areas to be weld- IMPORTANT: These are critical welding areas
ed. and no weld or weld splatter is allowable on surface
of wear strips.
2. Use 5/32-inch diameter low hydrogen AWS-ASTM
E-701 8 covered electrode.

NOTE: Flux covering on low hydrogen electrodes

readily takes on moisture which causes welding prob-
lems. Be sure electrodes are dry. Electrodes stored in
open containers should be suspected of containing ex-
cessive moisture and may require backing prior to use.

3. Use AC or DC reversed polarity welding current

(ELECTRODE POSITIVE [+I).

4. The suggested amerage range is 100 to 115

amps.

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-10 Track Systems TM-1 136 (Nov-78)

1 Weld the upper wear strips (I, Fig. 9) to track frame Refer to page l-0130-8 and install front idler as-
(2), melting as little as possible of the wear strips by sembly and track chain.
starting and maintaining the arc primarily on the track
frame. The wear strip is a high carbon steel so best Refer to Section 90, Group 9030 and adjust track
results are obtained by washing the weld metal toward tension and front idler guide adjustment.
the wear strip. This will produce a slightly convex weld
fillet. Connect negative battery ground strap or turn on
battery disconnect switch.

T439741

I-Upper Wear Strip 2-Track Frame

(2 used)

Fig. 9-Welding Upper Wear Strip

Weld upper wear strips to track frame using l/4-inch

(6.4 mm) fillet weld on the ends and a 9/32-inch (7.1
mm) bevel weld along the underside of wear strips
( (Fig. 9).

NOTE: These are critical welding areas and no

weld or weld spatter is allowable on surface of wear
strips.

Litho in U.S.A.
JO750 Crawler Bulldozer Tracks 1
TM- 1136 (Apr- 79) Track Systems 0130-l 1

FRONT CROSSBAR
REMOVAL

T43995N

l-Cap Screw (8 used) 2=-Speckd Washer (8 used) 3--sUPport 4-Front Crossbar

Fb. l&Front Crossbarand Suppori

NOTE: For additional working room when removing Remove spring cover from track frame.
front crossbar, the track chain on one side of the
crawler can be disconnected. If the track chain is not Using a hydraulic floor jack of at least 10 ton (89 000
disconnected, release track tension and support track N) (9 100 kg) capacity, raise crawler under main frame
chain so fhat the riont carrier roller can be removed. just far enough to relieve weight on front crossbar (4,
Fig. 10).

Litho in U.S.A.
1 Tracks JD750 Crawler Bulldozer
0130-12 Track Sys terns TM- 1136 (Mar-84)

A
CAUTION: Securely block under main frame Install excess shims between washers (6) and cross-
to hold crawler in raised position. bar stop (7).

Remove cap screws (5, Fig. 11) securing block pad IMPORTANT: Do not allow cap screws (5) to pro-
(8) and shims (4) to crossbar stop (7). Remove block pad trude from block pad (8). Operation of front crossbar
and shims from saddle frame (1). will be restricted if cap screws come in contact with
it.
Remove front carrier roller from support (3, Fig. 10).

Remove cap screws (1). Remove support (3) from

track frame and front crossbar (4).

Slide front crossbar from saddle frame.

INSTALLATION
Slide front crossbar into saddle frame with flat side
up.

Install support on front crossbar and track frame.

Install front carrier roller to support and secure with A-Shim B-Hold Down Pad
cap screws. C-Front Crossbar

Fig. 1 lA-Hold Down Pad Shims

Lower crawler to ground.
(Low Ground Pressure Bulldozer)

Install shims (4, Fig. 11) to obtain 0.00 to 0.06 inch For 750 Low Ground Pressure Bulldozer, use shims
(0.0 to 1.52 mm) clearance (3) between block pad (8) (A, Fig. 11A) to obtain 0.25 f 0.03 in. (6 + 0.8 mm)
and front crossbar (2). minimum clearance between hold down pad (B) and
front crossbar (C).

Install spring cover to track frame.

Connect track chain if disconnected.

Adjust track tension. (See Track Tension in Group

9030.)

!l’439?6N

l-Saddle Frame 5-Cap Screw (2 used)

P-Front Crossbar 6-Washer (2 used)
3-Clearance 7-Crossbar Stop
4-Shim (as required) 8-Block Pad

Fig, 1 l-front Crossbar Shim Adjustment

Litho in U.S.A.
JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Track Sys terns 0130-13

ROLLERS, IDLERS AND RECOIL SPRING

GENERAL INFORMATION TRACK ROLLER WEAR SPECIFICATION

Each track frame includes a support for the front idler, O.D. of new track roller . . . . . . . . . . . ~. . . . . 7.99 in.
two carrier rollers and track rollers. (203.0 mm)

Minimum recommended O.D. _ . . . . . . . . . . . 7.25 in.

750 Bulldozer has six track rollers on each side to
(184.2 mm)
support the load of crawler.
NOTE: For additional information on measuring
750 Low Ground Pressure Bulldozer has seven track track roller wear, refer to UNDERCARRIAGE APPRAIS-
rollers AL MANUAL SP-236.

Rock guards greatly reduce the entrance of foreign Removal

material into the track system and thereby increase
Release track tension by turning the ball check valve
track life.
one turn counterclockwise to allow grease to escape
from the track adjusting cylinder. Place a piece of pipe
The tracks are guided at the front by idlers which are
hydraulically shifted forward to adjust track tension. between the sprocket and the track chain and rotate the
track to retract the adjusting cylinder if required.

A
TRACK ROLLERS CAUTION: High pressure may be present in
the track adjuster cylinder. Do not visually in-
Measure Track Roller Wear
spect the grease escape passage.

Remove inner and outer rock guards.

Raise crawler high enough to remove rollers and

block under crawler securely.

Remove roller attaching cap screws and remove roll-

ers.

Repair
NOTE: Single flange rollers and double flange rollers
are of the same design. Disassembly and assembly pro-
cedures are the same for both types of rollers.

Remove snap rings (5, Fig. 13) from track roller shaft
Fig. 12-Track Roller Wear Measurement
(16).
Raise unit off the ground and block it for support. Remove inner collar (2) and outer collar (18) from
Release track tension by turning ball check valve one
track roller shaft.
turn counterclockwise to allow grease to escape from
track adjusting cylinder. Clean track roller to be mea- Remove seals (15) from shaft.
sured. Pull seal (7) from bushing case (13) and from inner and
outer collars.
Measure track roller using roller calipers and scale
from JT05518 or JT05523 Undercarriage Inspection Remove cap screws (8) securing bushing case and
Service Tool Kit. Measure inside and outside tread di- bushing to track rollers.
ameters of the roller at the area of most wear using the Place roller in a press and press the shaft and bushing
calipers; then measure caliper tip spread with the scale
case out.
to the nearest 0.020 in. (0.5 mm).
Turn roller over and reinstall shaft. Press shaft and
bushing case out of roller.

Litho in U.S.A.
1 Tracks JD750 Crawler Bulldozer
0130-14 Track System TM-l 136 (Nov-78)

16

T64293N

l-Lock &-Cap Screw (12 used) 14-O-Ring (2 used)

2-Inner Collar g-Lock Washer (12 used) 16-Seal (2 used)
3-Special Washer (4 used) lo-Bushing (2 used) %-Track Roller Shalt
4-Gap Screw (4 used) 11-Bushing Case (2 used) 17-Roller Shell
!&Snap Ring (2 used) 12-Pin (4 used) 16-Outer Collar
6-O-Ring (4 used) 13-Bushing Case Wiih Bushing lg--O-Ring
7-Metal Faced Seal (2 used) (2 used) 2gYPlug

Fig. 13-Single Flange Track Roller

16

4
P64294N

l-Lock 6-Gap Screw (12 used) 14-O-Ring (2 used)

2-Inner Collar g-Lock Washer (12 used) 16-Seal (2 used)
3-Special Washer (4 used) l&Bushing (2 used) 16Track Roller Shaft
4-Gap Screw (4 used) 11-Bushing Case (2 used) 17-Roller Shell
6-Snap Ring (2 used) 12-Pin (4 used) M-Outer Collar
6-O-Ring (4 used) 13-Bushing Case with Bushing 1 g-O-Ring
7-Metal Faced Seal (2 used) (2 u-4 2L%Plug

Fig. l4-Double Flange Track Roller

Litho in U.S.A.
 JD 750 Crawler Bulldozer Tracks 1
TM- I 136 (Mar-84) Track Sys terns 0130-1s

Press bushings from bushing case. Degrease bore in inner and outer collars (2 and 18)
and bushing case (11) with clean solvent before install-
Inspect bushings (10, Fig. 13) for scoring or exces-
ing seal (7).
sive wear.
Install seals (15) on track roller shaft. Install half of
Check track roller (17) and track roller shaft (16) for
seal (7) into bushing case and the other half into collar.
damage or excessive wear. Make sure oil passage in
Install O-ring portion of seal into bore in collars and
track roller shaft is clean and open.
bushing case.
Inspect seals and O-rings for cuts or other damage.
Install inner and outer collar with seal over track roller
Replace all parts as needed. shaft. Be careful not to damage seals (7 and 15).

Heat bushing case (11) to 3OO’F (149%) for installa- Secure collars to track roller shaft with snap rings (5).
tion of bushing (10). This will expand the bushing case
Use JD-313 Lube Nozzle Kit to fill track roller with oil
(11) enough to make it possible to align the holes in the
after assembly.
bushing flange with the dowel pins (12) in the bushing
case (11). Thoroughly clean the nozzle and around the plug end
of the track roller shaft.
Install O-ring (3, Fig. 15) on bushing case (2).
Insert the nozzle in the roller shaft as far as it will go.
Place roller (4) and bushing case (2) in a press and
install bushing case. Use guide screws (1) to align holes Force oil slowly through the nozzle and into the shaft
in bushing case and roller. until oil without air bubbles is seen leaking past the flats
on the nozzle.
Install lock washers (9, Fig. 13) and cap screws (8).
Remove the nozzle and install O-ring (19, Fig. 13) and
plug (20).
Use approximately l/2 pint (237 mL) of SAE 30 oil as
recommended in Section 1, Group V to fill track roller
assembly.
NOTE: Track rollers require oil only at the time of
assembly.

l’S6915N
15691%
l-Guide Screws 3-O-Ring
P-Bushing Case 447oller

Fig. 754nstalling Bushing Case

Turn roller (17, Fig. 13) over and install roller shaft (16)
and bushing case (11). Install guide screws and press
bushing into position.

Litho in U.S.A.
1 Tracks dD750 Crawler Bulldozer
0130-15A Track Systems TM- 1136 (Mar-64)

Installation
Using a track roller installation tool (see Special
Tools), position track rollers with oil fill plug toward out-
side of track frame.

For 750 Bulldozer, install single flanged track rollers in

the first, fourth and sixth positions and double flanged
track rollers in the second, third and fifth positions,
counting from front of unit.

For 750 Low Ground Pressure Bulldozer, install sin-

gle and double flanged track rollers alternately, begin-
ning and ending with a single flanged roller.

Install washers (3, Fig. 13) and cap screws (4). Tight-
en D-grade cap screw to 170 lb-ft (230 N.m). Tighten F-
grade cap screws (4) to 192-288 lb-ft (260-391 N-m).

Lower crawler onto track chain.

Refer to Group 9030 and adjust track tension.

Install inner and outer rock guards and track guides.

Litho in U.S.A.
JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Track Systems 0130-158

CARRIER ROLLERS

Measure Carrier Roller Wear Measure carrier roller wear of both treads using roller
calipers and scale from JT05518 or JT05523 Undercar-
riage Inspection Service Tool Kit. Position calipers over
the most worn area of the roller running surface, and
close until caliper tips just touch tread surface. Measure
caliper tip spread using the scale to the nearest 0.020 in.
(0.5 mm).

Also check for flat spots on carrier roller tread, which

indicate roller is not free to turn.

CARRIER ROLLER WEAR SPECIFICATION

O.D. of new carrier roller . . . . . . . . . . . . . . . . 6.50 ‘in.

796113
(165.1 mm)
Fig. 15A-Camw Roller Wear Measurement
Minimum recommended O.D. . . . . . . . . ~. . . 5.84 in.
(148.4 mm)

NOTE: For additional information on measuring car-

rierroller wear, refer to UNDERCARRIAGEAPPRAISAL
MANUAL SP-236.

Litho in U.S.A.
 1 Tracks, JD750 Crawler Bulldozer
0130-16 Track Systems TM- 1136 (Mar-84)

Removal Remove carrier roller, bearing cone and metal faced

seal (5) from carrier roller support (3).
Release track tension from track chain.

Bearing cones (9) that have been in service should be

Raise and support track chain so it is clear of carrier
thoroughly washed in volatile mineral spirits.
rollers.

Before inspection, oil the bearings with the same’type

Remove cap screws (1, Fig. 16) securing carrier roller
of oil that will be used in the carrier roller.
support (3) to track frame (rear) or front crossbar sup-
port (front).
NOTE: Never dry bearings with compressed air. Do
not rotate bearings while they are not lubricated.
Remove carrier roller and roller support from crawler.

Inspect bearings for roughness of rotation. Replace a

Repair
bearing if its rotation is still rough after cleaning and
Position carrier roller and roller support so that roller oiling.
cover is up.
Inspect bearings for scored, pitted, scratched,
Remove cap screws (15, Fig. 16) lock washers (14) cracked or chipped races, and for indication of exces-
and roller cover (13) from carrier roller. sive wear of rollers or balls. If one of these defects is
found, replace the bearing.
Remove cotter pin (12) and nut (11). Remove bearing
cone (9) and special washer (7).

3A
\

l’62209N

1 -Cap Screw (4 used) 4-Tap Bar (2 used) lo-O-Ring

2 -Special Washer (4 used) &--Metal Faced Seal 11-Nut
3 -Carrier Roller Support g--Carrier Roller 12-Cotter Pin
3A-Rear Carrier Roller 7-Special Washer 13-Roller Cover
Support (used with 6-Bearing Cup (2 used) 14-Lock Washer (3 used)
34 in. (660 mm) track g-Bearing Cone (2 used) 15-Cap Screw (3 used)
shoes only)

Fig. 76-Carrier Roller and Support

Litho in U.S.A.
 JD 750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Track Sys terns 0130-17
I

Inspect the carrier roller and carrier roller support for

grooved, burred, or galled conditions that indicate the
bearing has been turning in its housing or on its shaft. If
the damage cannot be repaired with crocus cloth, re-
place the defective parts.

Inspect metal faced seal (5) and O-ring (10) for cuts or
other damage. Replace parts as needed.

Clean and degrease bore in carrier roller and carrier

roller support cavity with clean solvent before installing
metal face seal (5).

Position carrier roller support (3) with shaft in vertical

position with threaded end up.
Ts6912NY

Install metal face seal (5), with seal retainer lip in the Ta =Actual Rolling L=Length of Torque
Torque Wrench
carrier roller support cavity.
Tw=Torque Wrench A=Distance From Center
Reading of Roller Shaft
Install bearing cone on shaft.
Fig. 17-Checking Rolling Torque
Use a piece of pipe that will fit over the shaft and on
Add approximately 16.6 ounces (491 mL) of SAE 30
the inner race to drive the inner bearing cone on. Make
oil to carrier roller cavity.
sure pipe does not contact rollers or roller cage.
Install O-ring (10, Fig. 16) on roller cover (13). Install
roller cover being careful not to damage O-ring.
Install bearing cups (8) in carrier roller (6) to bottom of
bore.
Apply Permatex Form-A-Gasket number 3 or an
equivalent to rollei cover cap screws. Install lock wash-
Install carrier roller (6) on support shaft. Make sure
ers and cap screws.
metal faced seal (5) is seated properly in seal bore.
NOTE: Carrier rollers require lubrication only at the
Install outer bearing cone (9), special washer (7) and
time of assembly.
nut (11).
INSTALLATION
Tighten nut (1‘1) while rotating carrier roller until 67 to Install carrier roller assembly on crawler.
73 lb-in. (7.6 to 8.2 N.m) (0.77 to 0.84 kg-m) rolling
torque is felt on carrier roller. When installing front carrier roller, position roller
flanges in a straight line with the flanges on the front idler
NOTE: Since the rolling torque is being checked at and rear carrier roller.
a point away from the centerline of the roller, the effec-
tive length of the torque wrench is increased. This Tighten “D” grade cap screws to 170 lb-ft (230 N.m).
Tighten “F” grade cap screws to 240 lb-ft (325 N.m). I
requires using the formula Ta = Tw -L + A to cal-
1504L
culate the actual rolling torque from the torque wrench Lower track onto rollers.
reading. See Fig. 17.
Refer to Group 9030 to adjust track tension and front
Back nut (11, Fig. 16) off l/4 turn and insert cotter pin. carrier roller alignment.

Litho in U.S.A.
1 Tracks JD750 Crawler Bulldozer
0130-18 Track Systems TM-7 136 (Mar-84)

FRONT lDLER

Measure Front Idler Wear

The front idler wears on the sides of idler flange and
idler running surface. The wear is caused by link con-
tact.

T58l8AC

A-Cap Screw C-Lock

B-Cap Screw (4 used) D-Cap Screw (2 used)

Fig. l&Measure front Idler Wear Fig. 19-Front Idler B/ock Assembly

Measure front idler wear using depth gauge from Remove cap screws (B, Fig. 19) and remove outer
JT05518 or JT05523 Undercarriage Inspection Service guide. Remove cap screws (D).
Tool Kit. Put crossbar of depth gauge on a cleaned area
of the center flange. The crossbar must be flat against Loosen cap screw (A). Strike head of cap screw (A) to
the surface and parallel to the idler shaft. Push scale dislodge lock (C). Remove cap screw and lock.
against tread surface so it is square against the most
worn area. Make sure scale is not at an angle. Remove blocks (12, Fig. 20) and inner guides (16)
from shaft (19).
Measure the outside tread and then the inside tread
opposite it to the nearest 0.020 in. (0.5 mm). Record the Remove metal face seals (23) and O-rings (28) from
average inside and outside tread dimensions. Measure block and bushing case.
in several locations around the idler to confirm the con-
sistency of wear. NOTE: During disassembly, rape the metal face
seals together to keep them in marched sets. Inspect
FRONT IDLER SPECIFICATION and replace if sealing pattern is excesively chipped or
scratched, or if the pattern has moved to the inside
Flange height of new front idler. . . . . . . . . . . 0.87 in. surface. Always install in pairs-two new sea/s together
(22.0 mm) or two used seals that were previously paired.

Maximum recommended flange height

for rebuilding . . . . . . . . . _ . . . . . . . . . . . . . 1 .l 1 in.
(28.3 mm)

Removal
Refer to page 0130-4 and split the track and remove
front idler.

Litho in U.S.A.
 JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Apr- 79) Track Systems 0130-19

a
T44145

l-Cap Screw (8 used) ll-Lock (2 used) 21-Lock Washer (12 used)

2-Special Washer (12 used) 12-Right-Hand Block 22-O-Ring (4 used)
8-Outer Guide (2 used) 18-Shim (as required) 28-Metal Faced Seal (2 used)
4-Shim (as required) M-Shim (as required) 24-Bushing Case (2 used)
8-Shim (as required) U--Inner Guide Wear Strip 28-Bushing (2 used)
8-Plug 1Mnner Guide 2”Pin (4 used)
7-O-Ring 17-Gap Screw (4 used) 27-Bushing Case With Bushing
k-Tapped Strip (4 used) l&Seal (2 used) (2 used)
8-Gap Screw (2 used) 14ldler Shatt 28-O-Ring (2 used)
18-Spectal Washer (2 used) 28-Gap Screw (12 used) 28--Front Idler Shell

I Fig. 20-Front Idler and Guide Assembly I

Remove cap screws (20, Fig. 20) from bushing case

(24).
Remove plug (6) and install a hydraulic puller into
the idler shaft as shown in Fig. 21.
Pull shaft with bushing case out of idler.

Install shaft (19, Fig. 20) into idler, with the threaded
hole end of the shaft protruding from the other bushing
case.

Turn idler over and pull the other bushing case in the
same manner.

Press bushing (25) from bushing case (24).

Inspect bushings (25 for scoring and excessive

wear. Fig. 21-Pulling Bushing Case From Idler

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-20 Track Systems TM- 1136 (Apr- 79)

II l’S69331

l-Wear Strip l-Inner Guide 3-6.25 in. (6.4 mm) Fillet Weld 4-0.25 (6.4 mm) Fillet Weld

Fig. 224nner Guide Wear Strip

1 Check front idler (29, Fig. 20) and idler shaft (19) for
damage or excessive wear. Make sure oil passages in
idler shaft are clean and open.

Inspect seals and O-rings for cuts or other damage.

Replace all parts as needed.

I If wear strips (15, Fig. 20) are to be replaced,

remove wear strips and grind all old weld off.

Weld new wear strips in using an E-7018 electrode.

Use a l/4 inch (6.4 mm) fillet weld on each end of the
wear strip and in both of the recessed areas in the
f inner guide. See Fig. 22.

Remove all weld and weld spatter from the surfaces

of the wear strip.

1 Heat bushing case (24, Fig. 20) to 300°F (149°C) for

installation of bushing (25). This will expand the bush-
ing case enough to make it possible to align the holes Fig. 234nstalling Bushing Case
in the bushing flange with the dowel pins in the bushing
case. Install the end of the idler shaft (19, Fig. 20) with the
tapped hole in it through the bushing case from the
Install O-ring (28) on bushing case. outside.

Install two guide screws into the front idler to keep Position bushing case and shaft to front idler and
the holes in the bushing case aligned with the holes in use a hydraulic puller to pull the bushing case into
the idler during installation. position (Fig. 23). Install cap screws and washers into
bushing case.

Litho in U.S.A.
JD750 Crawler Bulldozer Tracks -1
TM- 1136 (Apr- 79) Track System 0130-21

Position the seal over bore. Push down on the metal

face equally all around. Using a flat tool, force the seal
into the recess of the retainer. Make sure the rubber
seal is seated uniformly in the recess of the retainer. It
must sit straight in the bore.
Install inner guides against front idler.

Coat holes in block for idler shaft (19, Fig. 20) and 1
lock (11) with John Deere Never Seez or an equivalent
and install on shaft.

q
Install lock (11) and lock cap screw (9). Tighten cap
screws (9) to 35 lb-ft (47 Nm) (5 kg-m). Seat lock from
other side using a hammer and punch and retighten
cap screw to 35 lb-ft (47 Nm) (5 kg-m).

Install tapped strips (8), shims (4 and 5) outer

guides (3), cap screws (1) and washer (2).
Install shims (13 and 14) between inner guide (16)
Fig. 24-Installing Bushing Case
and block (12) and install cap screws.

Place the front idler in a press to install the other Tighten outer guide cap screws (1) to 85 lb-ft (115
bushing case. Nm) (12 kg-m).
Use JD-313 Lube Nozzle Kit to fill front idler with oil
Install guide screws to align holes in bushing case
after assembly.
with holes in idler.
Thoroughly clean the nozzle and around the plug
Install shaft (19, Fig. 20) and bushing case (24). end of the idler.
Insert the nozzle in the idler shaft as far is it will go.
Place a piece of pipe with approximately 4-l/8 in.
(105 mm) O.D. and at least 6 in. (152 mm) long over Force oil slowly through the nozzle and into the shaft
the shaft and on the bushing case. until oil without air bubbles is seen leaking past the flats
on the nozzle.
Place a steel plate over the pipe and press the
Remove the nozzle and install O-ring (7, Fig. 20) 1
bushing in (Fig. 24). Install cap screws and washers.
and plug (6).

Install O-rings (18, Fig. 20) on shaft (19). Use approximately l-1/5 pint (569 mL) of oil as
recommended in Section, Group V to fill front idler I
Degrease bore in right-hand (12) and left-hand assembly.
blocks and bushing case (24) with clean solvent before
NOTE: Front idlers require oil only at the time of
installing seal (23).
assembly or reconditioning.

NOTE: The metal face seal must be extremely

Installation
clean during this procedure. Use chloroethane to clean
the sea/s and wipe with lint-free tissue to remove finger Refer to page l-0130-8 and install front idler and
prints and foreign material. Place a drop of oil on a connect track chain.
cleaning tissue and coat the sealing patterns before
Refer to Section 90, Group 9030 and adjust track
mating the surfaces.
tension and front idler guides.

Install the rubber ring (22), on the metal seal (23)

before inserting into the retainer bores of the block (12)
and bushing case.

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-22 Track Systems TM- 1136 (Mar-84)

TRACK ADJUSTER AND RECOIL SPRING

(750 BULLDOZER)

NOTE: This procedure is for 750 Bulldozer. For 750

Low Ground Pressure Bulldozer, see Remove Recoil
Spring and Hydraulic Track Adjuster Assembly (Low
Ground Pressure Bulldoz&) in this group.

l--O-Ring 12-Spring Pln 23-Cap Screw (4 used)

l--Piston Spacer 13-Cylinder Retainer 24-Special Washer (4 used)
3-Track Adjuster Cylinder 14-Snap Ring PS-Deflector (2 used)
4-Track Adjuster Piston 15-Seal 26-Lock Washer (4 used)
5-Piston Wear Ring (2 used) M-Straight Grease Fitting 27-Cap Screw (4 used)
B-U-Cup Seal 17-Sal1 Check Valve 28-Cap Screw
I-Cap Screw (4 used) ltt-Fittfng Guard 29-Special Washer
8-Special Washer (12 used) 19-Track Adjuster Head 30-Front Idler Yoke
I)-Track Adjuster Housing 20-Track Adjuster Stop 31-Recoil Spring ( -296299)
10-Wiper Seal H-Lock Washer (6 used) Rscoil Spring (296300- 1
ll-Holddown Plate (2 used) 22-Cap Screw (6 used) 32-Spring Adapter

Fig. 25Track A@jmer

Litho in U.S.A.
 JO750 Crawler Bulldozer Tracks 1
TM- I 136 (Apr- 79) Track Systems 0130-23

Removal Compress spring enough to take the load off the

spring compressor tool and back the spring compres-
Refer to page l-0130-4 and 5 and remove track
sor tool out slightly less than the length of the press
adjuster assembly and recoil spring.
cylinders.

Repair
Slowly back off the press ram until all tension is
To service the recoil spring (31, Fig. 25) spring released from spring.
I adapter (32) or track adjuster housing (9) use the
following procedure to remove JD-314 special tool. Remove recoil spring, track adjuster housing and
spring adapter from press.
CAUTION: Use care when handling spring
a as accidental release of spring can cause Remove snap ring (14, Fig. 25) and remove cylinder j
serious personal injury. retainer (13) from track adjuster cylinder.

Install recoil spring assembly in a suitable press with Disassemble piston spacer (2) and track adjuster
track adjuster housing on the press bed and spring piston (4) from cylinder.
adapter centered with the press ram (Fig. 26).
Clean and inspect all parts for cracks, wear or other
damage.

Inspect O-rings for worn condition.

Replace parts as needed.

Check to see that recoil spring (31) is in good

condition. Replace if it has taken a permanent set.
Approximate free length of recoil spring ( -
296299) is 22.56 + 0.43 inches (573 -c 11 mm) with a
testing length of 18.21 + 0.39 in. (463 r 10 mm) at
19,000 lb (84 500 N). Approximate free length of recoil
spring (296300- ) is 23.29 * 0.43 in. (592 + 11
mm) with a testing length of 17.20 -+ 0.39 in. (437 2 10
mm) at 26.640 lb (118 500 N).

Fig. 26-Removing Spring Compressor Tool

NOTE: Use a press with at least 30 inches (762

mm) between the ram and press bed.

Extend press ram cylinders to approximately l/2 in.

(13 mm) from their fully extended position and tighten
the forcing screw down onto the spring assembly.

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-24 Track Svstems TM-l 136 (ADr-79)

If a new recoil spring is used or if recoil spring was

disassembled, it must be compressed and retained
with JD-314 recoil spring retaining tool until assembled
in track frame.

CAUTION: Use care when handling spring

a as accidental release of spring can cause
serious personal injury.

Assemble spring adapter, recoil spring, track ad-

juster housing (9, Fig. 25) and recoil spring retaining 1
tool *

Center the recoil spring assembly in a press with

spring adapter beneath ram and track adjuster housing
(9) on the press bed. Position spring adapter (31) so
the part number, located on square portion of adapter,
is in line with ears of adjuster housing (9).
l-Piston / 3-JD-316 Seal
2-U-Cup Seal Installation fool Compress recoil spring to 17.20 + 0.00 or - 0.26
inches (436.9 + 0.0 or - 6.6 mm), measured from
Fig. 27hstalling Seal
outer edges of spring, and retain with JD-314 special
tool.
1 Coat seal (2, Fig. 27) with oil before installing on

A
piston.
CAUTION: Always use the JD-314 special
tool to prevent accidental release of recoil
1 Clamp track adjuster piston (Fig. 27) in a vise with
spring.
seal groove exposed. Snap one side of seal (2) into
piston groove. Insert JD-316 Installation tool in piston
Retain recoil spring at this length until assembled in
and apply downward pressure while rotating tool han-
track frame and secured in position with holddown
dle against seal. Rotate tool handle one full turn to
plates (11).
insure seating of seal in piston groove.

I Install piston wear rings (5, Fig. 25) on track adjuster

piston (4).

Assemble piston spacer (2), track adjuster cylinder

(3) and piston assembly.

Press spring pin (12) flush with rear surface of

cylinder retainer (13).

Install track adjuster cylinder (3) in cylinder retainer

(13) and secure with snap ring (14).

Install seal (15) on track adjuster head. Assemble

O-ring filled groove to rear of unit.

Litho in U.S.A.
JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Track Systems 0130-25

Installation Install holddown plates (2, Fig. 29) to track frame.

Position two washers (4) between holddown plate and
Position preloaded recoil spring in track frame. Make
track frame and one washer between cap screw (3) and
sure top of spring is parallel to track frame.
holddown plate.

A
CAUTION: Do not release load on recoil
spring until it is installed in track frame and
secured in position with holddown plates. Accidental
release of coil spring can cause serious personal
injury.

Install wiper seal (10, Fig. 25) lip of seal facing front,
into track adjuster housing (9).

Position track adjuster assembly in track adjuster

housing. Be careful not to damage O-ring (1).

Secure track adjuster head to cylinder retainer. Posi-

tion track adjuster stop (20) to the bottom two holes.
l’S6942N
Install front idler yoke (30) to track adjuster head (19)
156942N

fig. ZB-lnsfalling Spring and secure with cap screw (28).

The track adjuster housing must be installed in track Tighten cap screw (28) to 340-510 lb-ft (461-691
frame in the position shown in Fig. 28. N-m). Rap head of cap screw using a 5 lb (2 kg) hammer
and retighten to 340-510 lb-ft (461-691 N.m).

Refer to page 0130-8 and install front idler assembly

and track chains.

Refer to Group 9030 and adjust track tension.

1 -Spring Adapter 5-Spring

2-Holddown Plate (2 used) g--Track Adjuster
3-Cap Screw (4 used) Housing
4-Washer (12 used) 7-JD314 Spring
Compressor

Fig. 29-Recoil Spring hstalled

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-26 Track Systems TM- 1136 (A pr- 79)

DRIVE SPROCKETS, CHAINS AklD SHOES

GENERAL INFORMATION DRIVE SPROCKET
Each track is driven from the rear by hardened
cast-steel sprocket bolted to the planet housing. Power
Removal
is received from the final drive planetary system. Refer to page l-0130-4 and remove track chain
from crawler.
The track chain has sealed pin and bushing con-
Remove sprocket shield from track frame.
nections.
Remove cap screws (1, Fig. 30) and washers (6) 1
Track shoes are available in a variety of widths and and pull sprocket (4) from the planet housing.
types to accommodate various ground and working
conditions. Installation
Apply John Deere Loctite Plastic Gasket or an
Track chains should never be reversed since doing
equivalent to threads of cap screws (1).
so will cause excessive bushing and sprocket wear.
Hoist sprocket (4, Fig. 30) onto planetary housing
and install cap screws (1) and washers (6).

Tighten D-grade cap screws to 300 lb-ft (407 Nm)

(42 kg-m).

Tighten F-grade cap screws to 425 lb-ft (576 Nm)

(59 kg-m).

Install sprocket shield on track frame.

Refer to page l-0130-34 and connect track chain. 1

T42282

I-Cap Screw (20 used) 3-L.H. Outer and R.H. Inner e-Sprocket
2-Special Washer (4 used) Sprocket Shield 6-LH. Inner and R.H. Outer
Sprocket Shield
GSpecial Washer (16 used)

I Fig. 30-Sprocket and Shields

Litho in U.S.A.
JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-841 Track Systems 0130-26A

Measure Sprocket Wear Measure sprocket wear using appropriate sprocket

gauge from JT05518 or JT05523 Undercarriage Inspec-
tion Service Tool Kit. Make sure the arrow on the gauge
points to the center of sprocket. Measure gap between
the other side of gauge and sprocket tooth. Allowable
wear is indicated on gauge.

NOTE: For additional information on measuring

track roller wear, refer to UNDERCARRIAGEAPPRAIS-
AL MANUAL SP-236.

Fig. 30A-Sprocket Wear Measurement

Litho in U.S.A.
1 Tracks JD750 Crawler Bulldozer
0130-268 Track Systems TM- 1136 (Mar-84)

TRACKSHOES Repair
Inspect shoes for excessive grouser wear, cracks or
Measure Track Shoe Wear
broken shoes.

Replace shoes as necessary

Installation

Fig. 31-Measure Track Shoe Wear

Clean grouser and track shoe plate surface to be

measured.

Measure grouser bar height using a depth gauge

from JT05518 or JT05523 Undercarriage Inspection
Service Tool Kit. Repeat measurement to nearest 0.020
in. (0.5 mm) for several grousers and record the aver-
age.
A-Rounded Edges
B-Chamfered Edges
TRACK SHOE WEAR SPECIFICATION
Fig. 37A-Track Shoe Nut installation
Full grouser height. . . . . . . . . . . . . . . . . . . 2.20 in.
(sealed and lubricated track) (56.0 mm) Track shoe mounting surfaces of links and shoes
must be clean and free of paint. Lubricate bolt threads
Minimum recommended full grouser height. . 0.89 in. and bearing surface of the head with oil.
. (22.5 mm)
IMPORTANT: Install all track shoe nuts with
NOTE: for additional information on measuring rounded edges (A, Fig. 31A) against the link and
track roller wear, refer to UNDERCARRIAGE APPRAIS- chamfered edges (B) away from the link.
AL MANUAL SP-236.
TRACK SHOE BOLT TORQUE SPECIFICATION
Removal
Standard shoe bolts . . . . . . . . . . .280 + 28 lb-ft
Remove bolts and nuts securing track shoe to link.
(sealed chain and lubricated chain) (380 + 38 N.m)

Remove shoe.
Swamp shoe bolts. . . . . . . . . . . . . . ,120 + 12 lb-ft
(sealed chain and lubricated chain) (163 I 16 N.m)

Tighten all bolts, then turn each an additional 180’

Litho in U.S.A.
JD 750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Track Systems 0130-26C

IMPORTANT: Do not use impact wrench to start

master shoe bolts.
I I
I I For units with lubricated chain, install master shoe on
O- 0 master link. Apply No. PT569 John Deere NEVER-
SEEZ@ Lubricant or an equivalent to master shoe bolts.
Start master bolts by hand to avoid cross-threading.
0x Tighten master bolts (A, Fig. 316) in a crisscross se-
/ quence as shown.

6A MASTER TRACK SHOE BOLT SPECIFICATION

796415
Master shoe bolts (standard shoe) . . .120 ? 12 lb-h
A-Master Shoe Bolts (163 r 16 N.m)

Fig, 31 B-Master Shoe Torquing Sequence Repeat tightening in same sequence.

Turn each bolt an additional 120’ in same sequence.

Master shoe bolts (swamp shoe) . . . . 120 + 12 lb-ft

(163 -t 16 N-m)

Repeat tightening in same sequence.

Turn each bolt an additional 180’ in same sequence.

NEVER-SEEZ is a trademark of the Never-See2 Com-

pound Corp.

Litho in U.S.A.
1 Tracks JD750 Crawler Bulldozer
0130-26D Track Systems TM- 1136 (Mar-84)

SEALED TRACK CHAIN Measure Bushing Outside Diameter

NOTE: This procedure is for units with a sealed track
Measure Link Height
chain. For units with a lubricated track chain, see Mea-
NOTE: This procedure is for units with a sealed track sure Bushing Outside Diameter for Lubricated Chain in
chain. For units with a lubricated track chain, see Mea- this group.
sure Link Height of Lubricated Chain in this group.

fig. 3 1C-Link Height Measurement

Measure link height to the nearest 0.020 in. (0.5 mm)

using depth gauge from JT05518 or JT05523 Undercar-
riage Inspection Service Tool Kit. Put the depth gauge
on outside of track link against pin boss as shown. Mea-
sure several links to the nearest 0.020 in. (0.5 mm).

LINK HEIGHT SPECIFICATION

Link height of a new chain . . . . . . . . . . . . . 4.06 in.

(103.1 mm)

Minimum recommended link height . . . . . . . . 3.69 in.

(93.7 mm) A-Reverse Drive Wear S-Forward Drive Side Wear

Fig. 31 D-Bushing Outside Diameter Measurement

Measure forward and reverse side wear of the bush-

ing using a caliper and scale from undercarriage inspec-
tion service tool kit. Position the caliper so that as it is
passed back and forth over the bushing, one tip will slide
parallel along the worn surface. Close caliper until the
opposite tip just touches the unworn side of the bush-
ing. Measure several bushings to the nearest 0.020 in.
(0.5 mm).

BUSHING OUTSIDE DIAMETER SPECIFICATION

Outside diameter of a new bushing . . . . . . . 2.31 in.

(58.8 mm)

Minimum recommended bushing outside

diameter (normal loading) . . . . . . . . . . . . . . 2.13 in.
(54.0 mm)

Minimum recommended bushing outside

diameter (high shock loading) . . . . . . . . . . . . 2.19 in.
Litho in U.S.A. (55.7 mm)
JO750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Track Sys terns 0130-27

Measure Track Pitch Measure track pitch using tape measure from under-
carriage inspection service tool kit. Measure a straight
NOTE: This procedure is for units with sealed track
section of chain, such as between carrier roller and idler.
chain. For units with lubricated track chain, see Measure
Measure from the left edge of one track pin to the left
Track Pitch for Lubricated Chain, this group.
edge of fifth track pin. This measurement covers the
wear in four pin and bushing joints.

Record measurement to the nearest 0.020 in. (0.5

mm) and repeat for several sections. Do not measure
across the master pin joint.

TRACK PITCH MEASUREMENT SPECIFICATION

Distance across four pins of new chain . . . 27.67 in.

(702.8 mm)

Maximum recommended distance across

four pins.. . . . . . . . . . . . . . . . . . . . . . . . . . 28.17 in.
(715.5 mm)
Fig. 31 E-Track Pitch Measurement

Place a pin or block between sprocket and chain. NOTE: For additional information on measuring
Move unit in reverse until chain is tight. sealed track chain wear, refer to UNDERCARRIAGE
APPRAISAL MANUAL SP-236.

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-28 Track Systems TM- 1136 (Mar-84)

l-Track Chain ?&Track Bushing (39 used) 6-Right Track End Link
2-Left Track Link (39 used) 6-Right Track Link (39 used) ( -279605)
( -279605) ( -279606) 9-Track Master Bushing
Laft Track Link (40 usad) Right Track Link (40 used) 16-Left Track End Link
(279606- ) (279606- ) ( -279605)
3--Seals (160 used) 7-Track Master Pin 11-Track Pin (39 used)
4-Spacer (2 used) T43979N
Fig. 3%Sealed Track Chain Assembly
I.

Removal
Raise the rear of the crawler using a floor jack of at
least 10 ton (9 100 kg) capacity and block it up securely.

A CAUTION: Do not work around

without securely blocking it up.
crawler

Use the dozer blade to raise the front of the crawler

and slide blocks under the front of the main frame.

A CAUTION: Make sure both tracks are clear

of the floor before rotating track.

Start engine and rotate track until master pin is on fig. 33-Pressing Out Master Pin I
the front idler about 6 inches (152 mm) from the floor.

A
Raise the dozer blade and secure it with a chain hoist. CAUTION’: Headless master pins are made
\ of extremely hard material. Do not try to
Release track tension by turning the check valve (2, drive out master pins with a hammer. Hard material
Fig. 2) one to three turns counterclockwise, which will can chip and cause serious personal injury and
allow grease to escape through the vent hole (3). damage to parts.

1 Remove track shoe(s) above the master pin. Move track assembly clear of crawler.

Use a D-0103OAA Master Pin Pusher or other suit-

able tool and press master pin from track links (Fig.
1 32).

Litho in U.S.A.
 JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Apr- 79) Track Svstems 0130-29

REPAIR

Track Disassembly and Assembly

The pins and bushings in the track assembly are
made of extremely hard material. They are manufac-
tured to press-fit tolerances. Accordingly, the track
cannot be disassembled without track-pressing
equipment equivalent to that described and illustrated
in the following instructions.

NOTE: Owatonna track press and tool set are il-

lustrated in the following instructions.

NOTE: Depending on shop facilities, the track

shoes may be complete/y removed from track chain
when servicing links, pins or bushings. The track
chain can be disassembled by removing track shoe
bolts from left links.
l-Right-Hand Link 6-32209 Saddle
Disassembly (Starting At Master Link) 2-Pin Remover 6-Left-Hand Link
3-26236 Disassembly Assembly
I Install 32209 Saddle (5, Fig. 34) and secure it to
Adapter Plate 740706 Abutment
track press frame with socket head cap screws. 4-Bushing Remover

Adjust conveyor extension to desired conveyor Fig. 34-Removing Right-Hand Link

working height.
Advance work head of track press until the ram end
Remove outside row of cap screws (row away disassembly adapter comes in contact with bushing
from work head or press) securing track shoes to link and pin. Press bushing, seals and pin from right-hand
assemblies. link. Remove right-hand link with shoe as an assembly
(Fig. 34). 1
Install ram end disassembly adapter plate to work
head of press and secure with attaching nut. Install Remove left-hand link, with bushing and pin intact,
forcing sleeve to disassembly adapter and secure from saddle.
with socket head cap screw.
To remove pins and bushings from left-hand links,
Raise the elevating conveyor and manually pull the position saddle bushing spacer (pin side) on saddle.
track chain assembly toward the press operator until Advance work head of track press and remove bush-
the link assembly bushing male end is directly over ing, seals and pin from left-hand link.
the top of the saddle.
Continue these steps with each link assembly until
Lower conveyor so that chain link assembly is in- the track is completely disassembled.
dexed into saddle.

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-30 Track Systems TM- 1136 (Apr- 79)

Assembly (Starting At Master Link) Adjust shims (2, Fig. 36) behind bushing abutment 1
(3) to provide 0.319 inch (8.10 mm) bushing standout
Remove ram end disassembly adapter from press
(7) from left track link (8).
head and install ram end assembly adapter (8, Fig. 35).
Install rear abutment assembly adapter (2) on press as
shown in Figure 35. Do not remove saddle (4).

I Position shims (2, Pig. 36) behind rear abutment

assembly adapter blocks to align abutment blocks so
that link assemblies remain loose during assembly.

With pin and bushing in saddle, position left link, with

track shoe mounting holes down, between saddle and
I,% I work head of press as shown in Figure 35. Advance
work head of press and press link onto pin and bush-
ing.

l-Pin Abutment GBushing Assembly

2-Shims Adapter
3-Bushing Abutment 7-Bushing Standout
4-Pin Assembly Adapter 8-Lett Track Link
5-Shims

Fig. 364nstalling Shims Behind Abutment

Adapter Hock

NOTE: The track shoe mounting holes are in the

down position. After the link is pressed onto the pin and
bushing, it becomes the left-hand link assembly.

After all left-hand links have been assembled with

140706 Abutment 6-Pin
pins and bushings, remove the saddle bushing spacer
2-30134 Rear Abutment ‘I-Lett-Hand Link
Assembly Adapter 8-25136 Ram End As-
(pin side) (5, Fig. 35). I
Plate sembly Adapter
3-30136 Pin Side Plate
Spacing Post 9-Bushing
4-32209 Saddle 18-30160 Bushing Side
5-25131 Saddle Bushing Spacing Post
Spacer (pin side)

Fig. 35-Preparing Press for Track Pin and

Bushing installation

Litho in U.S.A.
 _ JQ750 Crawler Bulldozer Tracks 1
TM- 1136 (Apr- 79) Track Systems 0130-31

l-End Links 5-Bushing

P-Bushing GLefl-Hand Link
3-Pin 7-25134f26111 Master
4-Right-Hand Link Bushing Spacer

Fig. 374nstalling Right Link to Let? Link

+ I
Install two seals (5, Fig. 38) over pin and into coun-
terbore of left track link. Install seals with inside diam-
eters touching.
I-Track Left Link 4-Track Right Link
With the conveyor in the raised position, install the P-Track Pin 6-Seals (4 used)
left-hand link assembly (6, Fig. 37) into the male end of 3-Track Bushing
Fig. 38-Track Chain Link Connection
the track chain. Lower the conveyor positioning the I
left-hand link assembly into the saddle. IMPORTANT: One link assembly should be
completely assembled prior to assembling vari-
Install right-hand link, with track shoes attached, and ous components. This is recommended because
seals in position. Advance track press.work head and it may be necessary, depending upon link wear,
, press right-hand link onto left-hand (Fig. 37). Continue to vary the number of adjusting shims behind the
to advance work head until right-hand link assembly is rear abutment assembly adapter blocks.
properly positioned so that bolt holes in track shoes
align with bolt holes in left link. NOTE: When the right-hand /ink is pressed onto
the pin, bushing and washers, use care to properly
If a new right link is to be installed, it will be neces- align the track shoe bolt holes with the left-hand link.
sary to remove the track bolts securing the track shoes
to the right-hand link. Continue these steps with each link assembly until
the track is completely assembled.

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-32 Track Systems TM- 1136 (Apr- 79)

Disassembly (Starting At Position Other To remove, cut bushings from track links (if links are
Than Master Link) to be re-used), attach disassembly adapter plate
(26236) (3, Fig. 34) to track press ram.

Place link with cut off bushing in saddle. Advance

ram head slowly until forcing sleeve comes in contact
with the bushing to be removed. Push bushing and
washers from link. Repeat procedure until all cut-off
bushings have been removed from links.

Assembly (Starting At Position Other

Than Master Link)
II Press a master bushing and track pin into left track
link. Use a master bushing spacer on bushing side
spacing post. Assemble all left-hand links removed.

Install two seals over pin and into counterbore of left

track link. Install seals with dished side opposite or
l-40706 Abutment 4-Removable Forcing
outward.
2-30134 Rear Abutment Pin
Assembly Adapter Plate 6-26236 Disassembly
3-30136 Pin Side Spacing Adapter Plate With the conveyor in the raised position, install the
Post 632209 Saddle left-hand link assembly into the male end of the track

I Fig. 39-Track Splitting

Other Than Master Link
chain. Lower the conveyor positioning the left-hand link
assembly into the saddle.

Install right-hand link and seals into position. Ad-

To replace a single bushing, pin, or link in the track
vance track press work head and press right-hand link
system it is not necessary to completely disassemble
onto left-hand (Fig. 37). Continue to advance work
the track. The procedure for this type of replacement is
head until right-hand link assembly is properly posi-
as follows:
tioned so that bolt holes in track shoes align with bolt
holes in left link.
Remove cap screws which secure track shoes to
link assemblies that are to be disassembled.
To assemble repaired section into track chain, re-
move ram end assembly adapter plate (7, Fig. 40)
Raise the elevating conveyor. Manually pull the
master bushing spacer (9), and saddle bushing spacer
track chain assembly toward the press operator until
the link to be disassembled is directly over the top of (5).
the saddle.

Lower conveyor so that chain link assembly is in-

dexed into the saddle.

Advance ram head of track press until removable

forcing pin (4, Fig. 39) comes in contact with pin to be
removed. Push pin from bushing. Raise track high
enough to remove pin from pin side spacing post (3).
After pin has been removed, lower and advance track
into position and remove remaining pin from link. With
a cutting torch, cut lower bushing in half to free right-
and left-hand links from the rest of track.

Litho in U.S.A.
 JD750 Crawler Bulldozer ~~.
-.- Tracks 1
TM- 1136 (Apr- 79) Track Systems 0130-33

Rotating Pins And Bushings

The wear on pins and bushings does not extend
over the entire surface of these parts; the life of worn
pins and bushings can often be restored by rotating
them 180 degrees with respect to the track link (Fig.
41). I

6
140706 Abutment 7-25136 Ram End
2-30134 Rear Abutment Assembly Adapter
Assembly Adapter Plate
Plate 8--Master Bushing
3-30136 Pin Side 9-25134/26111 Master
Spacing Post Bushing Spacer
4-32209 Saddle 10-30160 Bushing Side
5-25131 Saddle Bushing Spacing Post
Spacer 11-20614 Bushing Side
B-Left-Hand Link Shim T21529

l-Worn Side of Pin 2-Worn Side of Bushing

I Fig. 40-Master Bushing Installation

Fig. 41-Rotating Track Pins and Bushings I

Secure pin side plunger (26114) to disassembly
adapter plate (26236). Attach pin plunger and plate
assembly to press ram.

Place track chain in saddle in final assembly posi-

tion. Raise link high enough to position washers and
master bushing spacers into link counterbores. Lower
link into alignment with master bushing and press in
pin.

NOTE: install washers with dished side opposite or

outward. Install spacers with tapered side toward
bushing and f/at side toward washers.

Continue this operation until track is assembled.

Install track shoe and tighten lubricated cap screws

to 280 lb-ft (380 Nm) (39 kg-m).

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0130-34 Track Systems TM- 1136 (Apr- 79)

INSTALLATION Place the track link spacers (1, Fig. 42) in the 1
counterbores with the flat side of spacer against seal
Position track chain on the unit so that track shoe-
to-track link hardware, that is farther apart, is towards (2).
the rear when shoes are in contact with the ground.
Compress the track link spacers and seals with a
JD-302 Holding Tool.
Position two seals (2, Fig. 42) in each counterbore of
each end link. Position seals in counterbores, with
Align track link master bushing end with track link
insides touching and outsides apart (Fig. 42).
master pin hole.

Using a master pin pusher, push track master pin in

place.

Refer to Section 90, Group 9030 and adjust track

tension. I)

NOTE: To improve track chain life, replace seals

and spacers whenever master pin connection is bro-
ken. Replace master pin if necessary.
l'43175N

l-Spacer (2 used) 3-End Link

2-Seal (4 used)

I Fig. 42-Master Pin Connection Seal Placement

Litho in U.S.A.
 Track Systems/Recoil Spring

1 REMOVE RECOIL SPRING AND HYDRAULIC

TRACK TENSION ADJUSTER (LOW GROUND
PRESSURE BULLDOZER)

1. Remove track chain. (For sealed track chain, see Sealed

Track Chain Assembly Removal in this group. For lubricated
track chain, see Remove Lubricated Track Chain in this
grow.)

2. Remove front and rear recoil spring covers.,

3. Pump grease into track tension adjuster until spring is

compressed enough to remove preload spacers (A). Re-
move cap screws from each side to remove preload spacers.

A
CAUTION: Grease in track adjustment cylinder
is under high pressure. Slowly loosen check
valve fitting to release grease from track tension
adjuster.

4. Slowly turn check valve fitting counterclockwise one turn

to release grease through vent hole to release spring
compression.

A
CAUTION: Spring compression must be com-
pletely released before removing adjuster stop
(A)-

5. Push spring and adjuster housing apart using a pry bar

to make sure there is no compression left in spring. Remove
adjuster stop.

-itho in U.S.A. TM-1 136 (Mar-84)

TZX0130
P35
270284
 Track Systems/Recoil Spring

I
6. Pull the adjuster rod out of adjuster head.

A
CAUTION: Recoil spring and hydraulic track
tension adjuster weighs approximately 110 kg
(243 lb).

7. Carefully remove recoil spring and hydraulic track tension

adjuster assembly using a hoist and lifting strap.

Litho in U.S.A. 0130-36 TM-1 136 (Mar-84)

T23:0130
P36
270284
 Track Systems/Recoil Spring

1 DISASSEMBLE AND ASSEMBLE RECOIL SPRING AND HYDRAULIC TRACK TENSION

ADJUSTER (LOW GROUND PRESSURE BULLDOZER)

A-O-Ring E-Adjuster Head I -Grease Flttlng L-Spring Pin

B-Piston F-Relief Valve J-Check Valve M-Wiper Seal
C-Wear Ring (2 used) G-Cap Screw K-Bushing N-Adjuster Housing
D-Seal H-Retainer O-Recoil Spring

1. Disassemble track tension adjuster to inspect O-ring (A),

wear rings (C), and seals (D and M) for wear or damage.
Remove parts only if replacement is necessary.

2. Install seal (D) with lips toward end of piston (B) using
JD-316 Seal Installation Tool.

3. Install wiper seal (M) with lip toward flange end of adjuster
housing (N).

4. Assemble parts A-O. Install relief valve (F) in the

deepest threaded, hole of adjuster head (E) so it is below
the surface.

Litho in U.S.A. 0130-37 TM-l 136 (Mar-84)

T23;0130
P37270284
 Track Systems/Recoil Spring

INSTALL RECOIL SPRING AND HYDRAULIC

TRACK TENSION ADJUSTER (LOW GROUND
PRESSURE BULLDOZER)

1. Carefully install assembly so ears of track adjuster

housing are above center.

2. Make sure adjuster rod (A) is positioned so the flat side

is aligned with spring pin (B) in adjuster head.

3. Push adjuster rod into adjuster head.

4. Install adjuster stop (A). Install and tighten screws.

Litho in U.S.A. 0130-38 TM-1 136 (Mar-84)

n3;0130 P382m?84
 Track Systems/Recoil Spring
L I
,

5. Pump grease into check valve grease fitting until spring

is compressed enough to install preload spacers (A). Install
and tighten cap screws (B).

6. Install track chain. (For sealed track chain, see Sealed

Track Chain Installation in this group. For Lubricated Track
Chain, see Install Lubricated Track Chain in this group.)

Litho in U.S.A. 0130-39 TM-1 136 (Mar-84)

T67;0130
Pm230284
 Track Systems/Lubricated Track Chain

1 MEASURE LINK HEIGHT FOR LUBRICATED

TRACK CHAIN

1. Measure link height to the nearest 0.5 mm (0.020 in.)

using depth gauge from JT05518 or JT05523 Undercarrige
Inspection Service Tool Kit. Put the depth gauge on outside
of track link against pin boss as shown. Measure several
links to the nearest 0.5 mm (0.020 in.).

LINK HEIGHT SPECIFICATION

Link height of a new chain ...................... 103.1 mm (4.06 in.)

Minimum recommended link height ............... 93.7 mm (3.69 in.)

MEASURE BUSHING OUTSIDE DIAMETER

FOR LUBRICATED TRACK CHAIN

1. Clean surfaces to be measured of two adjacent bushings

and underside of track shoe in the area between bushings.

NOTE: Lubricated track chain bushings are measured for

vertical wear only. Bushings vertical wear can be
measured using either the depth gauge method or
caliper method.

2. For depth gauge method, put crossbar of depth gauge

from undercarriage inspection service tool kit across adja-
cent bushings as shown. Push scale against track shoe so
it is square with underside of shoe. Measure several different
bushings to the nearest 0.5 mm (0.020 in.)

BUSHING OUTSIDE DIAMETER SPECIFICATIONS

(Depth Gauge Method)

New bushing O.D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..s..... 72.7 mm

(2.66 in.)
Minimum recommended bushing O.D.
for high shock loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67.2 mm
(2.65 in.)
Minimum recommended bushing O.D.
for normal loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65.0 mm
(2.56 in.)

Litho in U.S.A. 0130-40 TM-1 136 (Mar-84)

n23:0130
P40
t70284
 Track Systems/Lubricated Track Chain

3. For caliper method put caliper from undercarriage inspec-

tion service tool kit around bushing at area of vertical wear
as shown. Measure several different bushings to nearest 0.5
mm (0.020 in.)

BUSHING OUTSIDE DIAMETER SPECIFICATION

(Caliper Method)

New bushing O.D. .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..!%.8mm

(2.31 in.)
Minimum recommended bushing O.D.
for high shock loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53.2 mm
(2.09 in.)
Minimum recommended bushing O.D.
for normal loading . .. .. . . . . . . . . . . . . . . . . . . . Al.1 mm
(2.01 in.)

MEASURE TRACK PITCH FOR LUBRICATED

TRACK CHAIN

NOTE: Track pitch does not extend unless there is lubrica-

tion leakage, which causes a dry joint. Measure pitch
only when there is a lubrication leakage or a visible
extension of a joint.

1. Place a pin or block between sprocket and chain. Then

move unit in reverse until chain is tight.

2. Measure from left side of pin in dry joint (A) to left side
of next pin.

TRACK PITCH SPECIFICATION

Pitch wear limit for single joint . . . .. . . . . . . . . . . . . . . ~. 190 mm

(7.5 in.)

Track pin may be operated with a dry joint until it reaches

wear limit specified. Then it must be repaired. A dry joint will
not hold lubrication until it is repaired. Track pin may break
if joint is not repaired after it reaches wear limit.

Litho in U.S.A. 0130-41 TM-1 136 (Mar-W;

Tm0130
PO1270284
 Track Systems/Lubricated Track Chain

REMOVE LUBRICATED TRACK CHAIN

A
CAUTION: High pressure may be present in
track adjuster cylinder. Do not visually inspect
grease vent hole.

1. Release track tension by turning check valve counter-

clockwise.

3AG;T96293 T47;0130 110 270184

2. Drive unit forward until master split link is over front idler.

3. Put wooden block under track shoe as shown.

4. Remove four bolts to remove master track shoe and

disassemble master split link.

5. Slowly drive unit in reverse direction to move track off

drive sprocket.

3AG;T96294, T96295 T47;0130 111 270184

Litho in U.S.A. TM-1 136 (Mar-84)

T23:0130
P4Z
270284
 Track Systems/Lubricated Track Chain

1 DISASSEMBLE LUBRICATED TRACK CHAIN

TO TURN BUSHINGS AND RELUBRICATE
CHAIN

NOTE The following procedure is for diassembly of track

chain to inspect, clean, replace damaged or worn
parts, turn bushings, and relubricate chain.

If track chain is disassembled only to turn pins and

bushings and no parts will be replaced, (see Disas-
semble Lubricated Track Chain to Turn Pins and Not
Relubricate, in this group.)

Lubricant leakage can cause a dry joint. An individ-

ual dry joint can be repaired and relubrica ted without
disassembling chain up to that joint. (See Disassem-
ble Lubricated Track Chain To Repair A Dry Joint
or Broken Link and Relubricate, in this group.)

1. Remove track shoes.

IMPORTANT: A clean track is necessary for proper

disassembly.

2. Wash chain with high pressure water. It will not be

necessary to wash links before reassembly if chain is
thoroughly cleaned.

NOTE: D-01037AA Tool Set for 750 sealed track can be

converted to tool set for 750 lubricated track by
using JHO 1742 Conversion Kit. Conversion kit con-
tains forcing pin (B), set screw (C), adapter plate (D),
cap screw (F), forcing pin sleeve (G) and adapter
plate (H).

3. Install disassembly tools from JT01741 Tool Set for

lubricated track or converted tool set on D-01031AA
200-Ton Twin Head Track Press. The TM-1 60 (Y7500) and
TM-200 Track Presses also use same tools.

A-Pin Side F-10102 Cap Screw

B-33263 Forcing Pin G-36014 Forcing
C-10153 Set Screw Pin Sleeve
D-200331 Right-Hand H-200330 Lefl-
Disassembly Hand Disassem-
Adapter Plate bly Adapter Plate
E-Bushing Side l-51635 Saddle

3AGTm
I
Litho in U.S.A. 0130-43 TM-1 136 (Mar-84)
7*3;0130
P43270284
 Track Systems/Lubricated Track Chain

IMPORTANT: Track press disassembly tools must be in

proper alignment with links to prevent
broaching of pin and bushing. Damaged
link bores cannot be reused.

4. Start disassembly at pin-end half of split link. Check for

proper alignment of tools with pin and bushing.

5. Make an index mark on bushings to aid in reassembly,

when turning bushings l/2 turn (180”) to expose a new wear
surface. - I L-d

A
CAUTION: Always wear safety glasses when A-Left Ram E-Bushing
operating the press. Parts may break or chip, &--Saddle F-Left Link
which could create a risk of personal injury. C-Right Ram G-Pin
D-Right Link

6. Extend right ram (C) to push pin (G) and bushing (E) from
the right link (D). The right link is forced against the side of
saddle (B) as pin and bushing are pushed out.

7. Retract right ram. The right link, with seals and thrust ring,
will stay on the ram tools.

3AG;T96266 T47;0130 I.13 270184

8. Extend left ram (A) to push the pin (C) and bushing (F)
from left link (G). The left link is forced against the side of
saddle (B) as pin and bushing are pushed out.

9. Retract left ram. The left link, with seal and thrust ring,
will remain on the ram tools.

10. Remove links, bushing, and thrust rings from press.

A-Left Ram E-Right Link

B-Saddle F-Bushing
C-Pin G-Left Link
D-Right Ram

3AG;T96267 T47;0130 114 270184 1

Litho in U.S.A. 0130-44 TM-1 136 (Mar-84)

n,;0130P44270284
 Track Systems/Lubricated Track Chain

11. Inspect parts as they are disassembled to determine

which ones can be reused. If there is internal wear at any
joint, replace seals (G), pin (D), bushing (B), and thrust rings
(H). These parts must be replaced to successfully relubricate
chain.

12. If pin and bushing contains oil when disassembled, new

pins, seals, bushings, or thrust rings are not necessary. Do
not remove useable seals from link counterbore. Do not
remove any dirt from around seals.

13. Repeat steps 4-12 to disassemble rest of chain.

14. Remove plug (E) and rubber stopper (F) from pins, using
a drill.

A-Left Link E-Plug

B-Bushing F-Rubber Stopper
C--Right Link G-Seals
D-Pin H-Thrust Ring

3AG;TSlbAC T47;0130 115 270184

15. Inspect pin ends. If the chamfer is missing due to wear,

grind a 3 mm (0.12 in.) x 15” chamfer on pin. If chamfer is
missing in stopper hole, add new 4 mm (0.16 in.) x 30”
chamfer.

16. Clean pins, bushings, and thrust rings in solvent.

A4 mm (0.16 in.) C-15

B-30” D-3 mm (0.12 in.)
3AG;T96269 T47;0130 116 270184

Litho in U.S.A. 0130-45 TM-1 136 (Mar-84)

TZwlmP45270284
 Track Systems/Lubricated Track Chain

ASSEMBLE LUBRICATED TRACK CHAIN TO

TURN BUSHINGS AND RELUBRICATE CHAIN

a CAUTION: Make sure all control levers of press

are In the NEUTRAL posltlon.

NOTE D-01037AA Tool Set for 750 sealed track can be

converted to tool set for 750 lubricated track by
using JTO1742 Conversion Kit. Conversion kit con-
tains shims (H) and plunger (K),

1. install assembly tools from JTO1741 Tool Set for lubri-

cated track or converted kit on DO1031AA 200-Ton Twin
Head Track Press. The TM-1 60 (Y7500) and TM-200 Track
Presses also use same tools.

A-261 12 Left-Hand Assembly I-Spacer (Not Required,

Adapter Plate This Appllcatlon)
S-25136 Right-Hand Assembly J-10372 Sprlng
Adapter Plate K-36016 Plunger
C--Spacer (Not Requlred, L-30147 Forcing Sleeve
This Appllcetlon) M-Spacer (Not Required,
D-26945 Spacer ThisAppllcetlon)
E-10370 Spring N-12916 Cap Screw
F-261 14 Plunger O-Pin Slde
G-30129 Forcing Sleeve P-51635 Saddle
H-261 16 Shim Q--Bushing Side
201253 Shlm
(As Required)

3AG;T96270, T96.271 T47;0130 200 060384

2. Apply oil to stopper (A). Install stopper in pin using

JDG169 Stopper Installation Tool (B).

3AG;T96272 T47;0130 201 060384

1

Litho in U.S.A. 0130-46 TM-1 136 (Mar-84)

n3;0130
P46270284
 Track Systems/Lubricated Track Chain

VOTE: The pin end halves of master split link must be

temporarily assembled to bushing end halves of
link for proper positioning on plungers. Pin end
halves will later have to be separated for installation
at end of chain.

3. Assemble master split link halves using master shoe bolts

and washers (as required). Tighten bolts just enough to hold
links together.

4. Install assembled split links on ram plungers.

5. Install bushing (A) in front seat of saddle (B) so the mark

is 180” opposite original location to expose a new wear
surface.

3AG;T96273 T47;0130 119 270184

6. Adjust track press pressure relief valve setting.

TRACK PRESS RELIEF VALVE SETTING

Pressure (maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 361 kPa

(164 bar)
(2663 psi)
Force (maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...376060 N
(65 000 lb force)

7. Advance left ram until left split link contacts the saddle.
Advance right ram until it stops to press split link and bushing
assembly together.

Litho in U.S.A. TM-1 136 (Mar-84)

T*3;0130
P47
270284
 Track Systems/Lubricated Track Chain

8. Measure bushing projection from shoulder of link using

a depth micrometer. Bushing projection determines clear-
ance between overlapping links and proper spacing of link
bolt holes.

BUSHING PROJECTION SPECIFICATION

Bushing projection .*........*......*........*..... 3.02 f 0.25 mm
(0.119 f 0.010 in.)

9. If bushing projection does not meet specification, check

pressure setting or adjust shim packs behind plungers. Only
the first two joints must be checked for proper bushing
projection.

10. Apply track chain lubricant to bushing ends before next

set of links are installed.

3AG:T96276 T47:0130 122 270184

IMPORTANT: Pins must be installed so cross-drilled

hole is toward link wear surface or they
may break when chain is used. To make
assembly easier, install all pins so holes
in the end are toward the same side of
chain.

11. Install pin in bushing so cross-drilled hole (B) is toward

link wear surface. Install all pins so hole (A) in the end is
toward the same side of chain, either left or right.

12. Install a thrust ring (A) on each end of pin.

13. Move completed split link assembly to rear seat of

saddle.

Litho in U.S.A. 0130-48 TM-l 136 (Mar-84)

n3;0130
P48ml284
 Track Systems/Lubricated Track Chain

14. Apply TY6299 John Deere Gasket Maker or an equiva-

lent to the link bore. The sealant prevents loss of vacuum
or lubricant leakage through the pin to link joint.

Litho in U.S.A. TM-l 136 (Mar-84)

T23:0130
Pa 270284
 Track Systems/Lubricated Track Chain

15. Install bushing (F) in front saddle seat. Install left (B) and
right (E) links on ram plungers.

Assemble the load ring (C) and seal ring (D). Install the
assembly into link (B) counterbore so pointed lip of seal ring
is toward bushing (F).

A-Thrust Ring F-Bushing

B-Link G-Pin
C-Load Ring H--Stopper
Meal Ring I--Plug
E-Link

3AG;T96280, T5816AA T47;0130 126 260284

Litho in U.S.A. 0130-50 TM-1 136 (Mar-84)

T23;0130
P50
270284
 Track Systems/Lubricated Track Chain

17. Advance left ram until left link contacts the saddle.
Advance right ram until it stops (plungers inI both rams
against shim pack).

A-Len Ram F--Right Llnk

&--Saddle G-Bushing
C-Pin H--Shims
D-Plunger I-Left Link I
E-Right Ram
3AG;T96282, T96283 T47;0130 128 270184

18. Retract left ram. Install DSD-301183 Special Spacer (A)

between the joint in the rear seat of saddle and ram. The
special spacer can be made from a new T73603 Track
Bushing. Spacer is approximately 38 mm (1.50 in.) long.

19. Advance left ram until track components are pushed

tight. Remove spacer.

Litho in U.S.A. TM-l 136 (Mar-84)

n3;0130
PS1280284
 Track Systems/Lubricated Track Chain

20. After one complete joint has been assembled, check

end play of track links to make sure bushing, thrust rings,
and link counterbore faces are pressed solid against each
other. Position base of dial indicator on one link assembly
and pointer against the other link assembly.

21. Pry link assemblies in one direction then in opposite

direction to measure the amount of end play. End play
should be zero, but a maximum of 0.13 mm (0.005 in.) is
allowed. If end play is more than amount specified, check
track press pressure relief valve setting.

22. As track chain is being further assembled, end play may

be checked by flexing each joint after each link assembly
is pressed together. End play is correct if links cannot be
rotated by hand.

23. As chain is being assembled, check to make sure there

is some clearance between the overlapping face of links,
using a feeler gauge. If links contact each other, check
bushing projection

BUSHING PROJECTION SPECIFICATION

Bushing projection . ..m........m.O.s....*s..m... 3.02 f 0.25 mm

(0.199 f 0.010 In.)

Litho in U.S.A. 013042 TM-l 136 (Mar-84)

-r23:0130
P52280284
 Track Systems/Lubricated Track Chain

24. Add lubrication (SAE 80W 90 oil) using a JT05462 Seal

Tester and Lubricator. Insert nozzle of lubricator into the pin
through the stopper. Depress control lever on the handle
enough to draw a vacuum of 68-l 02 kPa (20-30 in. Hg) as
indicated on the gauge.

25. Release lever. If there is no decrease in vacuum for a

minimum of five seconds, the joints are sealed. If there is
a vacuum decrease, seals are not sealing and the joint must
be taken apart and repaired.

26. Add oil by depressing the second lever. Oil pressure

(read on the same gauge) must be 140-205 kPa (1.4-2.05
bar) (20-30 psi) after both levers are released.

3AG;T96287 T47;0130 132 270184

27. Immediately after oil has been added, install stopper

plug using a JDG190 Plug Installation Tool. Lubricate each
joint immediately after assembly so only one joint will have
to be disassembled if a vacuum leak occurs.

28. Repeat Step lo-27 for all joints.

29. The last link assembled is the split link pin ends.
Assemble a set of extra “slave” split link bushing ends to
the pin ends using bolts and washers used in Step 3. Tighten
bolts just enough to hold split link together.

30. Install assembled split links on ram plungers.

31. Advance rams to press split links together.

32. Protect split link ends from damage during handling.

3AG;T96288 T47;0130 133 270184

I
Litho in U.S.A. 0130-53 TM-1 136 (Mar-84)
n3;0130
P53280.284
 Track Systems/Lubricated Track Chain

33. Install all track shoes except master shoe. Apply oil to
track shoe bolt threads and bearing surface of bolt head.

TRACK SHOE BOLT SPECIFICATION

Standard shoe bolts . . . . . . . . . . . . . . . . . . . 380 f 38 N.m

(280 f 28 lb-ft)
Swamp shoe bolts . . . . ~. . . . . . . . . . . . . . . 163 f 16 N-m
(120 f 12 lb-ft)
Tighten all bolts first, then turn each an additional 180”.

3AG;T96291.
T96292 T47;0130209 060384

Litho in U.S.A. 0130-54 TM-l 136 (Mar-84)

n3;0130
PYI280284
 Track Sys terns/L ubrica ted Track Chain

I DISASSEMBLE LUBRICATED TRACK CHAIN

TO TURN PINS AND BUSHINGS AND NOT
RELUBRICATE

NOTE: The following procedure is for disassembly of track

chain only to turn pins and bushings. (Chain is not
relubricated after assembly.)

/f this procedure does not apply to the repair job, see

Disassemble Lubricated Track Chain to Turn
Bushings and Relubricate Chain.

Lubricant leakage can cause a dry joint. An individ-

ual dry joint can be repaired and relubricated without
disassembling chain up to that joint. (See Disassem-
ble Lubricate Track Chain To Repair a Dry Joint or
Broken Link and Relubricate, in this group.)

1. Remove track shoes.

NOTE: D-01037AA Tool Set for 750 sealed track can be

converted to tool set for 750 lubricated track by
using JTO1742 Conversion Kit. Conversion kit con-
tains forcing pin (B), set screw (C), adapter plate (D),
cap screw (F), forcing pin sleeve (G) and adapter
plate (H).

2. install disassembly tools from JT01741 Tool Set or

lubricated track or converted tool set on D-01031AA
200-Twin Head Track Press. The TM-160 (Y7500) and
TM-200 Track Press also use same tools.

A-Pin Side F-10102 Cap Screw

B-33263 Forcing Pin G-36014 Forcing Pin Sleeve
C-10153 Set Screw H-200330 Left-Hand
D-200331 Right-Hand Disassembly Adapter
Disassembly Adapter Plate
Plate l-51635 Saddle
E-Bushing Side

3AG;T96265 T47;0130 210 270184

Litho in U.S.A. 0130-55 TM-1 136 (Mar-84)

T23;0130
P55280284
 Track Systems/Lubricated Track Chain

IMPORTANT: Track press disassembly tools must be in

proper alignment with links to prevent
broaching of pin and bushing. Damaged
links cannot be reused.

3. Check for proper alignment of tools with pin and bushing.

4. Make an index mark on bushings and pins to aid in

reassembly, when turning bushings i/2 turn (180”) to
expose a new wear surface.

A
CAUTION: Always wear safety glasses when
operating the press. Parts may break or chip,
which could create a risk of personal injury.

5. Extend right ram (C) to push pin (G) and bushing (E) from
the right link (D). The right link is forced against the side of
saddle (B) as the pin and bushing are pushed out.

6. Retract right ram. The right link, with seals and thrust ring,
will stay on the ram tools.

A-Left Ram E-Bushing

B-Saddle F-Left Link
C-Right Ram Q-Pin
D-Right Link

3AG;T96266 T47;0130 136 270184

7. Extend left ram (A) to push the pin (C) and bushing (F)
from the left link (G). The left link is forced against the side
of saddle (B) as pin and bushing are pushed out.

8. Retract left ram. The left link, with seal and thrust ring,
will remain on the ram tools.

9. Remove links and bushing from press.

10. Repeat Steps 4-9 to disassemble rest of chain.

11. All pins, bushings, seals, and thrust rings are used for
reassembly, because chain is not relubricated. Do not
remove stopper and plug from pins. Do not remove seals
from track links.

3AG;T96267 T47;0130 137 270184

Litho in U.S.A. 0130-56 TM-1 136 (Mar-84)

T23:0130
P56280284
 Track Systems/Lubricated Track Chain

I 12. inspect pin ends for wear. If there is no chamfer, grind

a new 3 mm (0.12 in.) x 15” chamfer.
t
h
1.
1

a
I
B

A-l 5”
6-3 mm (0.12 In.)
3AG;T5798AJ T4 7;0130 138 270184
-

13. Smooth area of track link wear (A) using a grinder, if

necessary.

3AG;T96289 T47;0130 139 270184

Litho in U.S.A. 0130-57 TM-1 136 (Mar-84)

523;0130
P5,280284
 Track Systems/Lubricated Track Chain

ASSEMBLE LUBRICATED TRACK CHAIN TO

TURN PINS AND BUSHINGS AND NOT RE-
LUBRICATE CHAIN

A
CAUTION: Make sure all control levers of press
are in the NEUTRAL position.

NOTE: D-01037AA Tool Set for 750 track can be converted

to tool set for 750 lubricated track by using JTO 1742
Conversion Kit. Conversion kit contains shims (H)
and plunger (K).

1. Install assembly tools from JTOI 741 Tool Set for lubri-
cated track or converted tool set on D-01031AA 200-Ton
Twin Head Track Press. The TM-160 (Y7500) and TM-200
Track Presses also use same tools.

A-261 12 L.H. Assembly I-Spacer (Not Required,

Adapter Plate This Application)
B-25136 R.H. Assembly J-10372 Spring
Adapter Plate K-36018 Plunger
C-Spacer (Not Required, L-301 47 Forcing Sleeve
This Application) M-Spacer (Not Required,
D-26945 Spacer This Application)
E-10370 Spring N-12916 Cap Screw
F-261 14 Plunger O-Pin Slde
G-30129 Forcing Sleeve P-51835 Saddle
H-261 16 Shim Q-Bushing Side
201253 Shim
(As Required)

3AG;T96270, T96271 T47;0130 208 060384

Litho in U.S.A. 0130-58 TM-l 136 (Mar-84)

T23;0~30
PC.8
280284
 TrackSystems/Lubricated Track Chain

NOTE: The pin end halves of master split link must be

temporarily assembled to bushing end halves of link
for proper positioning on plungers. Pin end halves
will later have to be separated for ins talla tion at end
of chain.

2. Assemble master split link halves using master shoe bolts

and washers (as required). Tighten bolts just enough to hold
link together.

3. Install assembled split links on ram plungers.

4. Install bushing (A) in front seat of saddle (B) so the mark

is 180” opposite original location to expose a new wear
surface.

3AG;T96273 T47;0130 141 270184

5. Adjust track press pressure relief valve setting.

TRACK PRESS RELIEF VALVE SE’lTNG

Pressure (maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 381 kPa

(184 bar)
(2683 psi)
Force (maximum) . . . . . . . . . . . . . . . . . ..*........o......... 378 080 N
(85 000 lb force)

6. Advance rams to press split links together until the

correct bolt spacing is obtained for the master shoe.

Litho in U.S.A. TM-1 136 (Mar-84)

n3:0130P59280184
I
 Track Systems/Lubricated Track Chain

IMPORTANT: Pins must be installed so cross-drilled

hole is toward link wear surface or they
may break when chain is used.

7. Turn pin end-for-end to get a new wear surface, then

install it into bushing so cross-drilled hole (B) is toward link
wear surface. install all pins so hole (A) in end of pin is toward
the same side of chain, either left or right side.

3AG;T96277 T47;0130 143 270184

Install a thrust ring (A) on each end of pin.

Move completed link assembly to rear seat of saddle.

3AG;T96278 T47;l

IO. Install bushing (G) in front saddle seat. Install left and
right links on ram plungers.

Il. Advance left ram until1 left link contacts the saddle.
Advance right ram until link is pressed together and bolts
can be installed through 23058 Track Gauge Plate.

A-Left Ram F-Right Link

B-Saddle G-Bushing
C-Pin H-Plunger Shims
D-Plunger I-Left Link
E-Right Ram J-23058 Track
Shoe Gauge
3AG;T96283, T96290 T47;0130 145 270184

Litho in U.S.A. 0130-60 TM-1 136 (Mar-84)

n3:0130
PbO
280284
 Track Systems/Lubricated Track Chain

12. As chain is being assembled, check to make sure there

is some clearance between the overlapping face of links
using a feeler gauge. If links contact each other, check
bushing projection

BUSHING PROJECTION SPECIFICATION

Bushing projection . . .. ....... . . . . . . . . . . . . .3.02 rt 0.25 mm

0.119 * 0.010 in.)

13. Repeat Steps 7-12 to assemble rest of chain.

14. The last link assembled is the split link pin ends.
Assemble a set of extra “slave” split link bushing ends to
the pin ends using bolts and washers used in Step 2. Tighten
bolts just enough to hold together link.

15. Install assembled split links on ram plungers.

16. Advance rams to press split links together until the

correct bolt spacing is obtained for the master shoe. Protect
split link ends from damage during handling.

3AG;T96286 T47;0130 213 060384

L

17. Install all track shoes except master shoe. Apply oil to
track shoe bolt threads and bearing surface of bolt head.
Install bolts and nuts. Make sure nuts are installed with
rounded edges (A) against the link and chamfered edges (B)
away from link.

TRACK SHOE BOLT SPECIFICATION

Standard shoe bolts ..... ........... . . . . . . . . . 360 f 38 N.m

(220 + 28 lb-ft)
Swamp shoe bolts . . . . . . . . . . . . . . . . . . . . . . . 163 f 16 N.m
(120 + 12 lb-ft)

Tighten all bolts first, then turn each an additional 180’.

3AG;T96291, T96292 T47;0130 214 060384

J

Litho in U.S.A. 0130-61 TM-l 136 (Mar-84)

T23:0130
Pt.1260284
 Track Systems/Lubricated Track Chain

DISASSEMBLE LUBRICATED TRACK CHAIN

TO REPAIR A DRY JOINT OR BROKEN LINK
AND RELUBRICATE

NOTE: Lubricant leakage can cause a dry joint. The follow-

ing procedure is for repair and relubrication of a
single dry joint or broken link without disassembling
chain up to that point.

If entire chain is disassembled to replace parts or

turn pins and bushings, see Disassemble Lubricated
Track Chain to Turn Bushings and Relubricate Chain
or Disassemble Lubricated Track Chain to Turn Pins
and Bushings and not Relubricate in this group.

1. Remove track shoes from link assembly to be repaired

and shoes adjacent to it.

2. Remove track chain. (See Remove Lubricated Track

Chain in this group.)

3. Lay out track chain with shoes against the floor and put
link assembly to be repaired on wooden block.

NOTE: Make sure there is enough working space to operate

A-33472 Aligning Adapter D-25500 Forcing Pin
masterpin pusher and hoist from both sides of track
B-Pin E-33936 Rear Forcing Pin
chain. C-22779 Pligning Bushing
(2 used)
4. Attach D-01 063AA 90 718 kg (100 ton) Master Pin Pusher
to a load positioning sling and hoist. Install tools (A and
C-E) from JT01743 Tool Set in master pin pusher.

5. Turn pin pusher crank until rear forcing pin (E) contacts
pin in the joint to be repaired. Advance rear forcing pin until
pin in links is pushed out of bushing.

Litho in U.S.A. 0130-62 TM-1 136 (Mar-84)

T23;0110
P62280284
 Track Systems/Lubricated Track Chain

6. Push links apart, using RL-50 Ram (A) from tool set and
spacer (B), just enough to separate joint. Remove seals (C).

NOTE: Push second pin out completely if repair is being

done to replace a broken link. App~) TY6299 John
Deere GasketMakeroran equivalent to thenewlink
pin bore. Install pin in one link with cross-drilled hole
toward link wear s&ace.

7. Advance rear forcing pin of master pin pusher 76 mm (3

in.) to push second pin (A) out of one link.

6. Install tools (B-D) from tool set in master pin pusher.

9. Advance master pin pusher rear forcing pin to pusn

L..^L:-- Clr-.. ,;-I,

A-Bushing C-35199 Bushing

B-35205 Bushing Pusher
Adapter D-33936 Rear Forcing
Pin

Litho in U.S.A. 0130-63 TM-l 136 (Mar-84)

T.?3:0130
P63280284
 Track Systems/Lubricated Track Chain

10. Remove pin (A) link and bushing assembly.

11. Advance rear forcing pin (A) to push bushing out : of link
using same tools used in Step 9.

Litho in U.S.A. 0130-64 TM-l 136 (Mar-84)

m3;0130
Pt.3
280284
 Track Systems/Lubricated Track Chain

1 ASSEMBLE LUBRICATED TRACK CHAIN TO

REPAIR A DRY JOINT OR BROKEN LINK
AND RELUBRICATE

NOTE Assemble link using a new bushing, pin, seals, and

thrust rings.

1. Install tools (A, C-D) from JTO 1743 Tool Set in D-

01063AA Master Pin Pusher.

A-305294 Rear Bushing C-35204 Bushing Installer

Assembly Plate D-33936 Rear Forcing Pin
B-Bushing

r
2. Advance rear forcing pin (B) until new bushing is pushed
into counterbore of rear bushing assembly plate (A) and
stops.

3. Measure bushing projection from shoulder of link using

a depth micrometer. Bushing projection determines clear-
ance between overlapping links and proper spacing of link
bolt holes.

BUSHING PROJECTION SPECIFICATION

/

Bushing projection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.119 f 0.010 mm

(3.02 f 0.25 in.)

Litho in U.S.A. 0130-65 TM-l 136 (Mar-84)

n3:0130
Pb5060384
 Track Systems/Lubricated Track Chain

5. Install the pin, link, and bushing assembly (A). Install

guide pin (E) from tool set to align links. Turn master pin
pusher around 180” to work from opposite side of chain.

6. Advance rear forcing pin until bushing (D) is pushed into

counterbore of rear bushing assembly plate and stops.

A-Pln, Link, and Bushing D-Bushing

Assembly E-305298 Guide Pin
B-33938 Rear Forcing Pln F-305294 Rear Bushing
C-35204 Bushlng Installer Assembly Plate

7. Measure bushing projection from shoulder of link using

a depth micrometer.

BUSHING PROJECTION SPECIFICATION

Bushing projection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.02 k 0.25 mm

(0.119 f 0.010 in.)

8. Install tools (A, C and E) from tool set in master pin

pusher. Align rearforcing pin (A) with track pin that is partially
pushed out. Advance rear forcing pin until track pin is pushed
into opposite link.

A-33938 Rear Forcing Pln D-305298 Guide Pln

B-22779 Allgnlng Bushing E-33472 Aligning
(2 used) Adapter
C-Track Pin

Litho in U.S.A. 0130-66 TM-l 136 (Mar-84)

T23:0130
P66
280284
 Track Systems/Lubricated Track Chain

9. 1APPlYtrack chain lubricant to bushirng ends.

10. Push links apart,, using RL-50 Ram from tool set alId a
spacer,jlJst en ough to assemble chain

NOTE: Sealant in link pin bore prevents loss of vacuum or

lubrication leakage through the pin to the link joint.

11. Apply TY6299 John Deere Gasket Maker or an

equivalent to the link pin bores (C). Do not apply sealant to
the counterbores (seal seats).

12. Clean and dry link counterbores (seal seats). Assemble

load ring (A) and seal ring (B). Install assembly into link
counterbore so pointed lip of seal ring is toward bushing (D).

13. Hold a thrust ring on each end of bushing as links are

carefully pushed together. Look through bore to be sure
parts are in alignment. Carefully install 305298 Guide Pin
from tool set through links, thrust rings, and bushing to keep
parts aligned.

14. Apply oil to stopper (A). Install stopper in a new pin using
JDG188 Stopper Installation Tool (B).

Litho in U.S.A. 0130-67 TM-l 136 (Mar-84)

T23:0~30
C67
280284
 Track Systems/Lubricated Track Chain

IMPORTANT: Track pin must be installed so cross

drilled hole is toward link wear surface or
it could break when chain is used.

15. Install tools (A, D and E) from tool set and new track
pin (C) in master pin pusher.

16. Advance rear forcing pin (E) until new track pin is pushed
through thrust rings, bushing, and both sets of links.

A-33472 Aligning Adapter D-22779 Aligning

B-305298 Guide Pin Bushlng (2 u&d)
C-Track Pin E-33936 Rear Forcing
Pin

17. Add lubrication (SAE 80W oil) to the repaired joint using
JT05462 Seal Tester and Lubricator. Depress control lever
on the handle just enough to draw a vacuum of 68-l 02 kPa
(20-30 in. Hg) as indicated on the gauge.

18. Release lever. If there is no drop in vacuum for a

minimum of five seconds, the joint is sealed. If there is a
vacuum drop, seal has not sealed and joint must be taken
apart again and repaired.

19. Add oil by depressing the second lever. Oil pressure

(read on the same gauge) must be 140-205 kPa (1.4-2.05
bar) (20-30 psi) after both levers are released.

Litho in U.S.A. 0130-68 TM-l 136 (Mar-84)

T23;0130
P68280284
 Track Systems/Lubricated Track Chain

20. Immediately after oil has been added, install plug in

stopper using a JDGlQO Plug Installation Tool.

21. For the joint where the pin was partially removed, push
the plug completely through the stopper using a small punch.
Be careful not to enlarge hole in stopper.

22. Repeat Steps 16-l 9 to lubricate the joint. Install a new

Plug-

23. Install chain. (See Install Lubricated Track Chain, in this

grow.)

24. Install track shoes. Track shoe mounting surfaces must

be clean and free of paint. Apply oil to bolt threads and
bearing surface of head. Install nuts with rounded edges (A)
against the link and chamfered edges (B) away from the link.

TRACK SHOE BOLT TORQUE SPECIFICATION

Standard shoe bolts . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . 380 f 38 N.m

(280 f 28 lb-ft)

1: :’ ,::
Swamp shoe bolts . . . . . . . . . . . . . . . . . . . . . . . ..*....... 183 f 18 N*m
‘<
(120 f 12 lb44

Tighten all bolts, then turn each an additional 180”. ‘,,

Litho in U.S.A. TM-1 136 (Mar-84)

n3;0130
Pb9280284
 Track Systems/Lubricated Track Chain

INSTALL LUBRICATED TRACK CHAIN

1. Put track under track frame with the wide end of links
toward rear of unit. Drive unit over chain until chain is
extended four or five shoes beyond the sprocket.

2. Put a pry bar through track link near the end of chain.
Guide track over sprocket while operator drives unit slowly
forward until chain is at top of sprocket.

3. Remove track shoe (A).

4. Put a chain through link next to split link, over rear carrier
roller, and under front carrier roller as shown. Attach chain
to a hoist. Slowly drive unit forward while using hoist to pull
track chain to front carrier roller. Remove the chain.

3AG;T96297 T47;0130 149 270184

5. Put a lifting strap around master split link bushing and

attach to a hoist. Lift track chain so wooden blocks can be
put under fourth track shoe. Slowly drive unit forward until
front idler is against track chain. Remove track shoe (A) next
to split link.

Litho in U.S.A. 0130-70 TM-l 136 (Mar-84)

n3;1164
Pm**0284
 Track Systems/Lubricated Track Chain

6. Remove any foreign material from master link tooth racks

(D) and ramp surfaces (B). Clean surface with wire brush if
iecessary.

7. Check for burrs, especially at tips (A) of master link ramps.

Remove all burrs so ramp surfaces are flat.

8. Check the holes (C) in each master link. The holes must
be clean and free of foreign material.

A-Tip of Master C-Holes

Link Ramp D-Tooth Rack
B-Ramp Surface
3AG;T96299 T47;0130 151 270184

I
9. Keep opposite side of unit from turning. Raise unit just
enough so bottom of sprocket is out of track chain.‘Use a
chain connected to link (B) and around bushing (A) at other
end of track chain to bring chain together over front idler as
sprocket is turned forward.

IMPORTANT: To prevent damage to threads, DO NOT

use a pry bar in bolt holes to align master
split link.

10. Carefully assemble the master links (A) together and

align the bolt holes.

11. Install master link track bolts by hand to check

alignment.

3AG:T96301 T47:0130 153 270184

Litho in U.S.A. 0130-71 TM-l 136 (Mar-84)

n3;0130
P71280284
 Track Systems/Lubricated Track Chain

12. Lubricate master shoe bolt threads and bearing surface

of bolt head using PT569 John Deere NEVER-SEEZs
Lubricant or an equivalent.

IMPORTANT: DO NOT use impact wrench to start

master shoe bolts to avoid cross-
threading.

13. Remove any foreign material from master shoe and link
mounting surface. Install master shoe on master links and
start bolts by hand to avoid cross-threading.

14. Tighten master bolts (A) in a crisscross sequence as

shown to 163 &- 16 N.m (120 f 12 lb&).

15. Repeat Step 14 in exact sequence to make sure master

bolts are to specifications. If unit is equipped with standard
shoes, then turn master bolts an additional 120”, using same
sequence. If unit is equipped with swamp shoes, turn each
master bolt an additional 180”, using same sequence.

16. Remove the chain.

17. Install remaining two track shoes and bearing surface

of bolt head.

TRACK SHOE BOLT SPECIFICATION

Standard shoe bolts e........-........--.......... 380 f 38 N-m

(280 f 28 lb-ft)
Swamp shoe bolts D..m........s....O....o......... 103 f 12 lb-fl
(120 f 12 lb-ft)
Tighten all bolts flrst, then turn each an addltlonal 180”.

3AG;T96302, T96303 T47;0130 225 060384

Litho in U.S.A. 0130-72 TM-l 136 (Mar-84)

T23:0130
P72
280284
 Track Systems/Lubricated Track Chain

18. Pump grease into track adjuster check valve lubrication

fitting until there is (38.1-50.8 mm) (l-1/2-2 in.) track
chain sag between front idler and carrier roller. (See Track
Tension Adjustment, in Group 9030).

Litho in U.S.A. 0130-73 TM-l 136 (Mar-84)

T73;ono
P73280284
 Track System/Lubricated Track Chain

bitho in U.S.A. 0130-74 TM-1 136 (Mar-64)

n3;0130
674ZBOZ(Y
JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Specifications and Special Tools 0199-l

Group 0199
SPECIFICATIONS AND SPECIAL TOOLS
TRACK SYSTEMS
SPECIFICATIONS AND TORQUE VALUES

- O.D. of a new carrier roller. . . . . . . . . . 6.50 in.

(165.1 mm)
Minimum O.D.. . . . . . . . . . . . . . . . . . . . 5.84 in.
(148.4 mm)

- Carrier roller rolling drag

torque . . . . . . . . . . . _ . . . . . . . . . 67-73 lb-in
(7.6-8.2 N.m)

- Carrier roller to track frame cap screw torque:

“D” grade. . . . . . . . . . . . . . . . . . . . .170 lb-ft
(230 N-m)
“F” grade . . . . . . . . . . . . . . . . . . . . . . .240 lb-ft
Fig. l-carrier Roller (325 Nsm)

- Track roller to track frame cap screw torque:

“D” grade. . . . . . . . . . . . . . . . . . . . . . .170 lb-ft
(230 Nem)
“F” grade . . . . . . . . . . . . . . . . . .192-288 lb-ft
(260-391 Nem)

- O.D. of a new track roller. . . . . . . . . . . 7.99 in.

(203.0mm)

Minimum roller O.D. . . . . . . . . . . . . . . . 7.25 in.

(184.2 mm)

Fig. Z-Track Roller

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0199-2 Specifications and Special Tools TM- 1136 (Mar-84)

TRACK SYSTEMS
SPECIFICATIONS AND TORQUE VALUES-Continued

1 - Clearance between block pad

and front crossbar . . . . . . . . . . . 0.00 to 0.06 in.
(0.0 to 1.52 mm)

Fig. 3-Front Crossbar Shim Adjustment

A- Clearance between hold down pad

and front crossbar (750 Low
Ground Pressure Bulldozer). . . . 0.25 f 0.03 in.
(6 + 0.8 mm)

Fig. I-Front Crossbar Ho/d Down Pad

1 - Sprocket cap screws (D-grade) . . . . .

(F-grade)

l’S69618

Fig. 5-Sprocket

Litho in U.S.A.
 JO750 Crawler Bulldozer Tracks 1
TM- 7 736 (Mar-84) Specifications and Special Tools 0199-3

TRACK SYSTEMS
SPECIFICATIONS AND TORQUE VALUES-Continued

1 - Standard shoe bolts torque

(sealed chain and lubricated chain) . .280 +- 28 lb-ft
(380 r 38 Nam)

Swamp shoe bolts torque

(sealed or lubricated chain). . . . . .120 f 12 lb4
(not illustrated) (163 + 16 Nem)

Tighten all bolts, then turn each an additional 180’.

T56954N 2 - Grouser height (new) (sealed or
F@ 6-Track Shoe
lubricated chain) . . . . . . . . . . . . . . . . . . . 2.20 in.
(56.0 mm)

Grouser height (minimum recommended

full grouser height. . . . . . . . . . . . _ . . . 0.89 in.
(22.5 mm)

A - Master track shoe bolts torque

(lubricated chain with standard shoe) 120 f 12 lb-ft
(163 f 16 N-m)
Repeat tightening in same sequence.
O- 0 Turn each bolt an additional 120’ in same sequence.

Master track shoe bolts

0x (Lubricated chain with swamp shoe) 120 + 12 lb-ft
(163 +- 16 N-m)

Repeat tightening in same sequence.

d A. Turn each bolt an additional 180’ in same sequence.

Fig. 7-Master Track Shoe Bolts Torquing Sequence

-Litho in U.S.A.
1 Tracks XV50 Crawler Bulldozer
0199-4 Specifications and Special Tools TM- 1136 (Mar-64)

TRACK SYSTEMS
SPECIFICATIONS AND TORQUE VALUES-Continued

Track chain pitch:

Distance across four pins of new chain . . . 27.67 in.

(702.8 mm)
Maximum recommended distance across
four pins.. l.. . . . . . . . . . . . . . . . . . . . . . 28.17 in.
(715.5 mm)

Fig. &Sealed Track Chain Putch Measurement

Lubricated track chain wear limit

of single joint . . . . . . . . . . . . . . . . . . . . ~~. . . . 7.5 in.
(190 mm)

Fig. PLubricated Track Chain Pitch Wear

Limit of Single Joint Measurement

Sealed chain and lubricated chain

link height (new chain) . e. . . . q. . . . . . . . . . . 4.06 in.
(103.1 mm)
Minimum link height. . . . . . . . . . . . . . . . . . . . 3.69 in.
(93.7 mm)

Fig. IO-Sealed Chain and Lubricated

Chain Link Height Measurement

Litho in U.S.A.
JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Specifications and Special Tools 0199=s

TRACK SYSTEMS
SPECIFICATIONS AND TORQUE VALUES-Continued

Sealed track chain bushing O.D. . . . . . . . . . . 2.31 in.

(new bushing) (58.8mm)

Minimum bushing O.D. . . . . . . . . . . . . . . . . . 2.13 in.

(normal loading) (54.0mm)

Minimum bushing O.D. . . . . . . . . . . . . . . . . . 2.19 in.

(high shock loading) (55.7mm)

15808AG

a--Reverse Drive Wear B-Forward Drive Wear

Fig. 1 l-Sealed Track Chain Bushing O.D. Measurement

Fig. 1%Lubricated Track Chain Bushing O.D. Measurement

(Depth Gauge Method)

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0199-6 Specifications and Special Tools TM- 1136 (Mar-84)

TRACK SYSTEMS
SPECIFICATIONS AND TORdUE VALUES-Continued

Lubricated track chain bushing O.D.

(new bushing) (Caliper Method) . . . . . . . . . . . 2.31 in.
(58.8mm)

Minimum bushing O.D. ~. . . . . . . . . . . . . . . . 2.01 in.

(Normal loading) (51.1 mm)
Minimum bushing O.D. e. . . . . . . . . . . . . . . . 2.09 in.
(High shock loading) (53.2mm)

Fig. 73-Lubricated Track Chain Bushing 0.0. Measurement

I (Caliper Method)

1 - Tighten block-to-idler
shaft lock cap screw to . . . . . . . 0. . . . . .35 lb-h
(47 N-m)

2 - Tighten outer guide-to-

block cap screw to. . . . . . . . . . e. . . . . . .85 lb-ft
(115 N-m)

T43983N

Fig. 14-Front Idler Block

Litho in U.S.A.
JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Specifications and Special Tools 019.9-7

TRACK SYSTEMS
SPECIFICATIONS AND TORQUE VALUES-Continued

1 - Adjust shim pack to make dimensions (A)

equal.

2 - Adjust shim pack to make dimensions (6)

equal

3 - Clearance between inner guide wear

strip and track frame wear strip. 0.00 to 0.04 in.
(0.0 to 1.O mm)

1 - Front idler yoke-to-track

adjuster head cap screw . . . . . . .340--510 lb-ft
(461-691 Nam)

NOTE: Tighten cap screw. Rap head of cap screw

with a 5 Ib (2 kg) hammer and retighten cap screw.

Fig. 1B-Front Idler Yoke

1 - Recoil spring free

length ( -296299) . . . . . . . 22.56 k 43 in.
(573 + 11 mm)
(296300- ) . . . , . . . 23.29 + 43 in.
(592 f 11 mm)
2 - Testing length of
recoil spring ( -296299) . 18.21 + 0.39 in.
(463 -+ 10 mm)
T43984N -k-- at 19,000 lb. (84 500 N)
fig. 77-Recoil Spring (296300- ) . 17.20 t- 0.39 in.
(437 * 10 mm)
at 26,640 lb. (118 500 N)

Litho in U.S.A.
1 Tracks JD750 Crawler Bulldozer
0199-8 Specifications and Special Tools TM- 1136 (Mar-84)

TRACK SYSTEMS
SPECIFICATIONS AND TORQUE VALUES-Continued

A-Front idler flange height (new). . . . . . . . . 0.87 in.

(22.0 mm)

Maximum recommended flange height . . 1.11 in.

(28.3 mm)

Fig. Id-front idler

Endplay.................................. 0

Maximum allowed . . . ~ . . . . . . . ~ . . . . . . . . 0.005 in.

when rebuilding chain (0.13 mm)

Fig. 7BLubricated ‘Track Chain End Ray

Litho in U.S.A.
JD 750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Specifications and Special Tools 0199-g

TRACK SYSTEMS
SPECIFICATIONS AND TORQUE VALUES-Continued

A - Pin stopper hole chamfer dimension . . . 0.16 in.

(4 mm)
B - Pin stopper hole chamfer angle . . . . . . . . . . 30”

C - Pin end chamfer angle . . . . . . . . . . . . . . . . . 1S’

D - Pin end chamfer dimension . . . . . . . . . . 0.12 in.

(3 mm)

Fig. 22-Lubricated Track Chain Pin Chamfer

Lubricated track chain bushing

projection . . . . . . . . . . . . . . . . . . . . .3.02 + 0.25 mm
(0.119 2 0.010 in.)

Fig. 23-Lubricated Track Chain Bushing Projection

Track press pressure relief valve setting:

Pressure (maximum) . . . . . . . . . . . . . . . . 2663 psi
(18 361 kPa)
(184 bar)

Force (maximum) . . . . . . . . . . . . . . 85,000 lb force

(378 080 N)
Vacuum pressure. . . . . . . . . . . . . . . . .20-30 in. Hg.
(68-l 02 kPa)

Oil pressure . . . . . . . . . . . . . . . . . . . . . . . 20-30 psi

(140-205 kPa)
T5797AC
(1.4-2.1 bar)
Fig. 24Seal Tester and Lubricator used for
Lubricated Track Chain Assembly

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0199-10 Specifications and Special Tools TM- 1136 (Mar-84)

TRACK SYSTEMS
SPECIFICATIONS AND TORQUE VALUES-Continued

Begin with cap screw (A); tighten using cross pattern

Turn cap screws an additional 120’

Fig. 23-Pivot Shaft Cap Screw Tightening

Sequence

Litho in U.S.A.
JD 750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Specifications and Special Tools 0199-11

TRACK SYSTEMS
SPECIAL TOOLS

Essential Tools

Tool Number Use

JD-314 Track Spring Compressor - to re-

move or install recoil spring in track
frame.

Fig. 24-Track Spring Compressor

JD-316 Track Adjuster Seal Installation Tool

-to install track adjuster piston seal.

Fig. 25Seal installing Too/

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0199-12 Specifications and Special Tools TM- 1136 (Mar-84)

TRACK SYSTEMS
SPECIAL TOOLS-Continued

Essential Tools-Continued Tool Number Use

JD-313 F’ront idler Lube Nozzle Kit - con-
tains JD-313-1 Nozzle and JD-
313-2 Adapter -to refill front idler or
track rollers with oil after recondi-

fig. 26-Front Idler Lube Nozzle Kit

Y-760 or Y-7000 Track disassembly and

Track Press assembly

T31623N VJ

D-01 031 AA Track disassembly and

assembly

Fig. 27-Track Presses

Litho in U.S.A.
JD750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Specifications and Special Tools 0199-a

TRACK SYSTEMS
SPECIAL TOOLS-Continued

Essential Tools-Continued Tool Number Use

25234 Tooling Set* Track disassembly and as-

Tool
sembly (sealed track chain).
l- 25234 includes the following:

1 - 26236 Disassembly Adapter Plate

2 - NONE Forcing Pin :
3 - 110996 Cap Screw
4 - 26110 Forcing Sleeve D/sassembly
5 - NONE Bushing Side Spacer
6 - 32209 Saddle
7 - 25131 Saddle Bushing Spacer
8 - 30134 Rear Abutment Assembly
Adapter Plate
9 - 20614 Pin Side Shim (2 used)
10 - 30136 Pin Side Spacing Post
11 - 30160 Bushing Side Spacing Post
12 - 20614 Bushing Side Shim
13 - 10098 Cap Screw
14 - 26822 Pin Side Spacer
15 - 30149 Pin Side Forcing Sleeve
Fig. 28-25234 Tooling Set 16 - 26114 Pin Side Plunger
17 - 10370 Pin Side Spring
18 - 25136 Ram End Assembly Adapter
Plate
19 - 30147 Bushing Side Forcing Sleeve
20 - 26477 Bushing Side Plunger
21 - 10373 Bushing Side Spring
22 - ---
10098/l 2916 Cap Screw
23 - 25134/26111 Master Bushing Spacer
24 - NONE Pin Side Spacer
25 - 26943 Bushing Side Spacer

* Use with Y-760 or Y-7000 Track Press

Litho in U.S.A.
 1 Tracks JO750 Crawler Bulldozer
0199-14 Specifications and Special Tools TM- 1136 (Mar-84)

TRACK SYSTEMS
SPECIAL TOOLS-Continued

Essential Tools-Continued Tool Number US0

26188 Tooling Set* Track disassembly
and assembly
26188 includes the following:

1 - 26112 Assembly Adapter

2 - 26235 Disassembly Adapter
3 - 40884 Saddle
4 - 26236 Disassembly Adapter
5 - 25136 Assembly Adapter
6 - 26111 Master Bushing Spacer
7 - 26116 Shims
8 - 21622 Track Gauge Plate
9 - 20535 Hand Plug
10 - 26111 Master Bushing Spacer
11 - 26115 Shims

* Use with D-01 031AA Track Press

I fig.29-26788 Tooling Sef

Litho in U.S.A.
JO750 Crawler Bulldozer Tracks 1
TM- 1136 (Mar-84) Specifications and Special Tools 0199-l 5

TRACK SYSTEMS
SPECIAL TOOLS-Continued

Essential Tools-Continued

fool Tool Number Use

JTO1741 Track disassembly and assembly

-
Tool Set (Lubricated track chain).
r,,
Tool set includes the following: ‘.k -
1
Disassembly ;
:

A - 51835 Saddle t.
B - 33263 Forcing Pin
c - 10153 Set Screw
D - 200331 Right-Hand Disassembly Adapter
Plate
-
E - 10102 Cap Screw
F - 36014 Forcing Pin Sleeve Tz.
7%r
796421 G - 200330 Left-Hand Disassembly Adapter
Fig. do-Track Press Disassembly Tools Plate

Assembly
A - 26112 Left-Hand Assembly Adapter Plate
B - 25136 Right-Hand Assembly Adapter Plate
c - Spacer (Not Required)
D - 26945 Spacer
E - 10370 Spring
F - 26114 Plunger
G - 30129 Forcing Sleeve
H - 26116 Shim
201253 Shim
(As Required)
I - Spacer (Not Required) g
J - 10372 Spring
K - 36018 Plunger
L - 30147 Forcing Sleeve
M- Spacer (Not Required)
79Mz N - 12916 Cap Screw
Fig. 3 1-Track Press Assembly Tools 51835 Saddle (Not Illustrated)
21622 Track Shoe Gauge (Not Illustrated)

Litho in U.S.A.
1 Tracks JD750 Crawler Bulldozer
0199-16 Specifications and Special Tools TM- 1136 (Mar-84)

TRACK SYSTEMS
SPECIAL TOOLS-Continued

Essential Tools-Continued

Tool Tool Number Use

JDG189 Stopper Installation Tool - to install

rubber stopper in lubricated track
chain pin.

Fig. 32-Stopper installation Tool

DSD-301183 Special Spacer - used for assembly

of lubricated track chain on press.

NOTE: Special spacer can be made

from T73603 Track Bush-
ing. Spacer is approximate-
ly 1SO in. (38 mm) long.

Fig. 33-Special Spacer

bitho in U.S.A.
 JD750 Crawler Bulldozer Tracks 1
TM- 1736 (Mar-84) Specifications and Special Tools 0199-17

TRACK SYSTEMS
SPECIAL TOOLS-Continued

Essential Tools-Continued

Tool Number lb

JT05462 Seal Tester and Lubricator - to test

seals and add lubrication to lubricat-
ed track chain.

Fig. 34-Seal Tester and Lubricator

JDG190 Plug Installation Tool - to install

stopper plug in lubricated track
chain pin.

T5797AD

Fig. 35Plug Installation Tool

: “Y :~ ;,c, ‘-‘,__ JD-204 To install metal face seals.

‘; :.
, _,., **c LIc*_
.,’
.,,. ; _,‘,
<,
,, ,,

,
._

Fig. 36-Seal Installation Tool

JT05516 Undercarriage Inspection Service

JT05523 Tool Kit - to check track system
(not shown) component parts for wear.

Litho in U.S.A.
1 Tracks JD 750 Crawler Bulldozer
0199-18 Specifications and Special Tools TM- 1136 (Mar-84)

TRACK SYSTEMS
SPECIAL TOOLS-Continued
e

Essential Tools-Continued

Tool Tool Number Use

D-01 0633AA loo-Ton Master Pin Pusher - to re-

move and install pin and bushing to
repair individual joint in lubricated
track chain.

fig. 37-loo-Ton (90 718 kg)

Master Pin Pusher

JD01743 Used with D-01063AA Master Pin

Tool Set Pusher to remove and install pins
and bushings from a lubricated track
chain to repair a single dry joint or
broken link.

Tool set includes the following:

Pin Removal
A - 33472 Aligning Adapter
B - 22779 Aligning Bushing (2 used)
C - 25500 Forcing Pin
D - 33936 Rear Forcing Pin

fig. 38-Pin Removal Tools

Pin Installation
A - 33472 Aligning Adapter
B _ 305298 Guide Pin
c - 22779 Aligning Bushing (2 used)
D - 33936 Rear Forcing Pin

fig. 39-Pin lnsta//ation Too/s

Litho in U.S,.!i.
i
 Tracks 1
JO750 Crawler Bulldozer
Specifications and Special Tools 0199-19
TM- 7 736 (Mar-84)

TRACK SYSTEMS
SPECIAL TOOLS-Continued

Essential Tools-Continued
Use
Tool Tool Number

Tool Set-Continued

Tool set includes the following:

Bushing Removal

A-35205 Bushing Adapter

B-351 99 Bushing Pusher
C-33936 Rear Forcing Pin

Fig. 40-Bushing Removal Tools

Bushing Installation

A-305294 Rear Bushing Assembly Plate

B-35204 Bushing installer
C-33936 Rear Forcing Pin

Fig. 41 -Bushing installation Tools

RL-50 To separate links of lubricated track

chain to repair a single dry joint or
broken link. (Included in JT01743
Tool Set.)

Fig. 42-Ram Pusher

Litho in U.S.A.
1 Tracks JD750 Crawler Bulldozer
0199-20 Specifications and Special Tools TM- 1136 (Mar-84)

TRACK SYSTEMS
SPECIAL TOOLS-Continued

Convenience Tools Tool Number Use

---- Track Roller Installation Tool - To in-
stall roller in track carrier.

This tool is used with a large floor jack with lift pad
removed. To make the tool, weld two half inch (12 mm)
rods or angle irons (2, Fig. 43) approximately 24 inches
(610 mm) long, to a pulley (3) that has a flange that will fit
into the jack lift pad hole. A 2010 Crawler crankshaft
pulley is suggested as sufficient size.

Weld a rod (6) across the top of the half inch (12 mm)
rods or angle irons (opposite end of pulley) to prevent
roller from sliding off. Rods or angle irons should be
placed close enough together to prevent roller from fall-
1283258 728325N
ing through.
1-Track Roller 4-Weld
a--Rods or Angle Irons S-Modified Floor Jack
3-Pulley B-Rod

Fig. 43-Track Roller Installation Tool

Litho in U.S.A.
 JD750 Crawler Bulldozer Tracks .l
TM- 1136 (Mar-84) Specifications and Special Tools 0199-21

TRACK SYSTEMS
SPECIAL TOOLS-Continued

Convenience Tools-Continued Tool Number Use

Tool JD-302 Sealed Track, Seal Holding Tool - to
hold master pins seals in place when
installing master pin.

2’43992N
/OR!WN
Fjg. 44-Sealed Track, Seal Ho/ding Tool D-01 030AA 50-Ton Master Pin Pusher - to re-
move or install track master pin. Re-
_,
: quires hydraulic pump for operation.

Fig. 4550-Ton Master Pin Pusher

D-01 019AA Hydraulic Hand Pump - to operate

D-01 020AA 50-ton master pin pusher
D-01 021 AA
D-01 027AA
D-01 022AA
D-01 023AA

Fig. 46-Hydraulic Hand Pump

Litho in U.S.A.
 1 Tracks JD750 Crawler Bulldozer
0199-22 Specifications and Special Tools TM- 1136 (Mar-84)

Litho in U.S.A.
JD750 Crawler Bulldozer Axles and Suspension System 2
TM- 1136 (Apr- 79) Drive Axle Housing 0201-l

Section 2
AXLES AND SUSPENSION SYSTEMS
CONTENTS OF THIS SECTION

Page Page
Group 0201 - DRIVE AXLE HOUSING Group 0299 - SPECIFICATIONS AND
General Information . . . . . . . . . . . . . . . . . . . 0201-3 SPECIAL TOOLS
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0201-3 Specifications and Torque Values
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0201-5 Drive Axle Housing. . . . .... .. . 0299-l
Installation . . . . . . . . , . . . . . . . . . . . . . . . . . . 0201-5 Axle Shafts, Bearings and
Reduction Gears , . . . . . . . . . . . . . . . 0299-2
Group 0250 - AXLE SHAFT, BEARINGS Special Tools
AND REDUCTION GEARS Drive Axle Housing. . . . . . . . . . . . 0299-3
General Information . . . . . . . . . . . . . . . . . . . . 0250-l
Planet Housing with Pinions and Shafts
Removal . . _. . . . . . . . . . . . . . . . _ . . 0250-2
Repair . . . . . . . . . _. . . . . . . . . . . . 0250-2
Installation. . . . . . . . . . . . . . . . _. . . . 0250-2
Final Drive Housing Cover with Gears
and Shafts
Removal . . . . . . . . . . . . . . _ . . . . . . . . 0250-5
Repair
Disassembly . . . . . . . . . . . . _. . . . . . . . . 0250-7
Assembly . . . . . . . . . . . . . . __. _. . . . . . . 025043
Installation. . . . . . . . . . . . . . . . . . . . . . . . 0250-l 1
Metal Face Seals
Inspection and Cleaning . . . . . . . . . . . . . 0250-l 2
Proper Installation. . . . . . . . . _. . . . . . . . . 0250-13

Litho in U.S.A.
2 Axles and Suspension System JD750 Crawler Bulldozer
0201-2 Drive Axle Housing TM- 1136 (Apr- 79)

bitho in U.S.A.
JD750 Crawler Bulldozer Axles and Suspension Systems 2
TM-l 136 (Nov-78) Drive Axle Housing and Support 0201-3

Group 0201
DRIVE AXLE HOUSING AND SUPPORT
GENERAL INFORMATION
The final drive housing is attached to the outboard
side of the transverse case.

The parking brake assembly is located within the

final drive housing.

REMOVAL
NOTE: The reasons for removing the final drive as
an assembly would be for servicing the parking brake
assembly or replacing the final drive housing. When
removing the components that make up the final drive,
refer to Group 0250.

Refer to Group 0130 and disconnect the track chain.

Fig. FTrack Frame Dowel

Raise front of crawler until front crossbar member is

free to move in front crossbar support.

Pry track frame forward until dowel (Fig. 2) is fully

removed from final drive housing.

Lower the front of unit.

Raise rear of crawler high enough to disengage

sprocket from track chain. Securely block under
crawler.

Remove transmission bottom guard.

l--Cap Screw (8 used)

Fig. 1-Cap Screw Locafion

Remove cap screws (1, Fig. 1) securing track frame

assembly to final drive housing and crawler frame.

Litho in U.S.A.
2 Axles and Suspension Systems JO750 Crawler Bulldozer
0201-4 Drive Axle Housing and Support TM-1 136 (Nov-78)

Remove upper two cap screws on final drive hous-

ing vertical centerline and install a JD324 Transmission
Holding Plate (1, Fig. 4) to transmission housing and
transverse case.

Use washers to fill the gap between the motor

holding plate and transmission if required.

Fig. 3-Final Drive Drain Plug

Remove drain plug (Fig. 3) and drain oil from final

drive housing. l-External Cap Screw 3--JD347-1 Final Drive
(9 -w Lifting Tool
2-Final Drive Housing 4-Safety Chain

Fig. 5Final Drive Lifting Tool

Remove six cap screws securing final drive housing

to transverse case and transmission housing.

Remove external cap screws (1, Fig. 5) securing

final drive housing to transverse case.

Secure a JD347-1 Final Drive Lifting Tool (3) to the

top two 98 in. tapped holes on the final drive housing
(2).

Install safety chain (4) with hooked end in outside

slot and bolt other end to final drive housing bolt hole.

Use a hoist with a lifting capacity of at least 2-ton (17

800 N) (1 815 kg). A floor lift crane would be best for
removing final drive.

l-JD324 Transmission Holding Plate NOTE: When using an overhead hoist, a JD347-2
could be used in conjunction with JD347-7 for access
Fig. 4-Transmission Holding Plate around sump tanks. See SPECIAL TOOLS, page
(Fuel Tank Removed for Clarity)
0299-4.

Remove six internal cap screws securing final drive

housing to transverse case.

Litho in U.S.A.
JD750 Crawler Bulldozer Axles and Suspension Systems 2
TM- 1136 (Apr- 79) Drive Axle Housing and Support 0201-5

INSTALLATION
Secure the JD347-1 Final Drive Lifting Tool on final
drive housing (Fig. 5).

Apply John Deere Loctite Plastic Gasket or an

equivalent to a clean bolting surface of final drive
housing and transverse case.

Position final drive assembly on unit. Coat internal

splines in motor shaft and external splines of final drive
pinion shaft with John Deere Never-See2 or an equiv-
alent. Use a JD326 Transmission Motor Spline Align-
ment Tool to align internal splines of motor output shaft
with external splines of final drive shaft.

l-Brake Line Connector 2-Final Drive Assembly

Fig. 6-Removal of Final Drive

Disconnect hydraulic brake line from long male

connector (1, Fig. 6) on inside of final drive housing.

Remove final drive assembly (2) from unit.

REPAIR
Refer to Group 0250 and remove planet housing,
sprocket frame and final drive housing cover.

Refer to Group 1111 and remove parking brake

assembly.
26221 ON

Clean final drive housing thoroughly and inspect for l-Cap Screw (2 used) 5-O-Ring
cracks, excessive wear or other damage. Replace as 2-Washer (2 used) 7-Long Male Connector
3-Gap Screw (15 used) &Pipe Plug
needed.
&-Washer (15 used) g-pipe Plug (2 used)
5-Final Drive Housing
Apply John Deere Plastic Lead or an equivalent to
pipe plug holes and install plugs. fig. 7-Installing Final Drive

Refer to Group 1111 and install parking brake as- Connect hydraulic brake line to long male connector
sembly. (7,Fig. 7).

Refer to Group 0250 and install final drive housing,

sprocket frame and planet housing.

Lifho in U.S.A.
2 Axles and Suspension Systems JD750 Crawler Bulldozer
0201-6 Drive Axle Housing and Support TM- 1136 (Apr- 79)

install the six internal cap screws (3, Fig. 7) with Install enough cap screws to secure the transmis-
washers (4) securing final drive housing to transverse sion to the transverse case and final drive. Remove the
case. JD324 Transmission Holding Plate and install the other
cap screws needed.
Remove the final drive lifting tool.
install cap screws (I, Fig. 7) and washers (2) in
Install the external cap screws (3) with washers (4). lifting tool holes.
Tighten D-grade cap screws (3) to 300 lb-ft (407 Nm)
(41 kg-m). Tighten F-grade cap screws to 425 lb-ft Fill final drive housing with recommended oil (See 1
(576 Nm) (59 kg-m). Section I, Group V) to fill plug level. I

bitho in U.S.A.
JD750 Crawler Bulldozer Axles and Suspension System 2
TM- 1136 (Apr-79) Axle Shaft, Bearings and Reduction Gears 0250-l

Group 0250
AXLE SHAFT, BEARINGS AND
REDUCTION GEARS
GENERAL INFORMATION

@-

a--

T6698P

I-Final Drive Gear IO-Planet Housing IS-Brake Hub

2-Final Drive Housing Cover 1 I-Sprocket Frame N-Planetary Brake Disk (4 us
3-Planet Carrier Cover 12-Seal Ptl-Disk Cover
4-Planetary Ring Gear 13-Shim (as required) PI-Planetary Brake Separator
5-Retainer Plate M-Pinion Shaft Quill Plate (3 used)
6-Sun Pinion Shah 15-Spacer 22-Brake Housing
7-Roller (57 used) 16Brake Piston 23-Brake Plate
&-Planetary Pinion Pin (3 used) 17-Final Drive Shaft 24-Final Drive Housing
g--Planet Pinion (3 used)

Fig. l-Final Drive System

Litho in U.S.A.
 2 Axles and Suspension System JD750 Crawler Bulldozer
0250-2 Ax/e Shaft, Bearings and Reduction Gears TM- 1136 (Apr- 79)

Power is transmitted from the transmissions to the Inspect gears for scuffed, nicked, burred, or broken
drive sprocket by a double reduction final drive. A spur teeth. If the defect cannot be removed with a soft
gear and planetary system provide a 38.23 speed honing stone, replace the gear.
reduction. The final drive shaft pinion and final drive
gear make up the spur system while the planetary Inspect gear teeth for wear that may have destroyed
system is contained in the outer planet housing. the original tooth shape. If this condition is found,
replace the gear.
A multiple wet disk, spring applied-hydraulic release
parking brake is provided. The brakes are automati- Inspect the thrust faces of gears for scores,
cally applied with loss of transmission pressure or scratches, and burrs. Remove such defects with a soft
when the engine is turned off. honing stone.

Dynamic b&king of the transmission units elimi- Coat bores in planet housing with Loctite Plastic
nates the need for service brakes and steering Gasket or an equivalent before installing planetary
clutches. pinion pins (6).

NOTE: It is not necessary to remove the final drive Press planetary pinion pin (6) in planet housing (2)
housing when servicing the planet housing with pinions to bottom of counterbore.
and shafts or the final drive housing cover with gears
and shafts. These assemblies can be removed sepa- Install one thrust washer (4) over planetary pinion
rately or as a unit. shaft.

PLANET HOUSING WITH Install planet pinion (7), rollers (5), and thrust washer
PINIONS AND SHAFTS (4). Coat rollers with oil after installing rollers in planet
pinion.
Removal
NOTE: Clean and dry oil from tapped holes in
Drain oil from planet housing.
planet housing (2) and cap screws (9) before applying
Loctite Plastic Gasket or equivalent to holes and
1 Refer to page l-0130-28 and disconnect track
screws.
chain.
Install planet carrier cover (8) and secure with cap
Raise crawler high enough to disengage sprocket screws (9). Planet carrier cover should be pulled down
from track chain. Securely block under crawler. evenly with cap screws. Tighten cap screws (9) to 170
lb-ft (230 Nm) (24 kg-m).
Remove outer sprocket shield and sprocket.
Installation
Remove four cap screws (10, Fig. 2) from recessed
pockets in flange and remove planet housing with Apply Loctite Plastic Gasket or an equivalent to the
pinions and shafts from sprocket frame using 4-314 mating surface of the planet housing and secure planet
cap screws that were used to fasten sprocket, use as housing to sprocket frame with cap screws (10, Fig. 2).
push screws. Clean old Loctite from planet housing. Coat threads of holes in sprocket frame with plastic
lead or an equivalent.
Repair
Install sprocket and tighten D-grade cap screws to
Remove cap screws (9, Fig. 2) and planet carrier
300 lb-ft (407 Nm) (41 kg-m). Tighten F-grade cap
cover (8) from planet housing (2). Use 3 screws in
screws to 425 lb-ft (576 Nm) (59 kg-m). Install outer
cover to remove cover from dowels.
sprocket shield.

Remove thrust washers (4) planet pinions (7) and Refer to page l-0130-34 and connect chain.
rollers (5), taking care not to lose any of the rollers.
Refer to Section I, Group V and fill planet housing
NOTE: If any rollers are lost or damaged, replace with recommended type and quantity of oil.
as a complete set.
Tighten fill and drain plugs just tight enough to
prevent leakage. Torque not to exceed 75 lb-ft (102
Nm) (10 kg-m).

Litho in U.S.A.
 JD750 Crawler Bulldozer Axles and Suspension System 2
TM- 1136 (Feb-77) Axle Shaft, Bearings and Reduction Gears 0250-3

~44532N

“Thrust Washer (6 used) &Planet Carrier Cover

l-Pipe Plug (2 used)
,* 6--Roller (67 used) 9-Cap Screw (9 used)
2-Planet Housing
6-Planetary Pinion Pin IO-Cap Screw (4 used)
: 3-Hollow Dowel (3 used)
(3 used)
7-Planet Pinion (3 used)

Fig. 2-Planet Housing With Pinions and Shafts

Litho in U.S.A.
2 Axles and Suspension System JD750 Crawler Bulldozer
0250-4 Axle Shaft, Bearings and Reduction Gears TM- 1136 (Feb- 77)

FINAL DRIVE HOUSING COVER WITH GEARS AND SHAFTS

/
ZA Y __
12
13
/
\
\
(0 4
t
/

\ /JJ
\ @its c
\
\
\ >@ 0” - T
1
2
\
\
\
21/
0
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w
0
3 \
0
b \
\ K
I
\
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\
2 4 \
v

, \
.s
ti

2’484921

l-Cap Screw (6 used) &Sprocket Frame 1Cil Seal

2-Retainer Plate &Bearing Cone %--Ball Bearing I
3-Planetary Ring Gear lo-Sealing Ring (2 used) 17-Snap Ring
4-Sun Pinion Shaft 1 l-Sprocket Frame Seal l&Final Drive Gear
.- ._. .
6-Bearing Cone 12-Gap Screw (4 used) i9-washer
6-Bearing Cup 18-Special Washer (22 used) N-Retaining Ring
7-Bearing Cup M-Final Drive Housing 21-Gap Screw (18 used)
Cover

Fig. 3-final Drive Housing Cover and Sprocket Frame

Litho in U.S.A.
JD750 Crawler Bulldozer Axle and Suspension System 2
TM- 1136 (Apr- 79) Axle Shaft, Bearings and Reduction Gears 0250-5

REMOVAL

Fig. 4Final Drive Drain Plug

Refer to Group 0130 and disconnect track chain. l--Cap Screw (6 used) 3-Ring Gear
a--Retainer Plate
Drain oil from final drive housing (Fig. 4).
Fig. SRemoving Planetary Ring Gear

Refer to page 0250-2 and remove the planet hous-

Remove cap screws (1, Fig. 5), retainer plate (2) and
ing with pinions and shafts.
planetary ring gear (3) from final drive housing cover.

Litho in U.S.A.
2 Axle and Suspension System JD750 Crawler Bulldozer
0250-6 Axle Shaft, Bearings and Reduction Gears TM- 1136 (Apr- 79)

l-Final Drive 2=-Gap Screws (22 used)

Housing Cover

Fig. 7-Removing Final Drive Housing Cover

Remove cap screws (2, Fig. 7) securing final drive

housing cover (1) with gears and shafts to final drive
housing.
l-Sprocket Frame l--Metal Face Seals

Fig. 6-Removing Sprocket Frame Remove final drive housing cover assembly.

Remove sprocket frame (1, Fig. 6) from final drive

housing cover. Remove metal face seals (2). Tag the
metal sealing rings as to which was installed in the
sprocket frame and final drive housing cover.

NOTE: During disassembly, tape the metal face

sea/s together to keep them in matched sets. Refer to
page 0250-72 for proper handling and inspection of
metal face seals.

Litho in U.S.A.
JD750 Crawler Bulldozer Axles and Suspension System 2
TM- 1136 (Apr- 79) Axle Shaft, Bearings and Reduction Gears 0250-7

REPAIR Remove cap screws (6, Fig. 8) and remove final

drive shaft quill (7). NOTE: Keep relative shim pack (8)
Disassembly together.

Remove final drive shaft assembly (9) from final

drive housing cover.

l-Final Drive SFinal Drive Gear

Housing Cover 6-Gap Screw (6 used)
2-Snap Ring 7-Final Drive Shaft Quill
3-Special Washer &Shims (as required)
4-Sun Pinion Shaft %-Final Drive Shaft
Assembly

fig. &Final Drive Cover Assembly l-Snap Ring 2-Ball Bearing

Remove snap ring (2, Fig. 8) and special washer (3) Fig. g-Removing Ball Searing

from sun pinion shaft (4).

Remove snap ring (1, Fig. 9) and pull ball bearing (2)
Pull sun pinion shaft out of final drive housing cover from final drive housing cover.
(1).
Pull bearing cone from planetary ring gear and
Remove final drive gear (5) from final drive housing bearing cone from final drive housing cover.
cover.
Pull bearings from final drive shaft assembly (9, Fig.
8).

Litho in U.S.A.
2 Axles and Suspension System JD750 Crawler Bulldozer
8250-8 Axle Shaft, Bearings and Reduction Gear TM- 1136 (Am- 79)

inspect bearings for roughness of rotation. Replace Press bearing cup (1, Fig. 10) tight against shoulder
a bearing if its rotation is still rough after cleaning and in final drive housing cover.
oiling.
Install oil seal (2) in final drive housing cover 0.125
inspect bearings for scored, pitted, scratched, (3 mm) beyond bearing bore.
cracked or chipped races, and for indication of exces-
sive wear of rollers or balls. If one of these defects is
found, replace the bearing.

Inspect the housing and shaft of the defective bear-

ing for grooved, burred, or galled conditions that indi-
cate the bearing has been turning in its housing or on
its shaft. If the damage cannot be repaired with crocus
cloth, replace the defective part.

Inspect gears for scuffed, nicked, burred, or broken

teeth. If the defect cannot be removed with a soft
honing stone, replace the gear.

Inspect gear teeth for wear that may have destroyed

the original tooth shape. If this condition is found,
replace the gear. l-Ball .Bearlng 2-Snap Ring

Fig. 11 -Installing Ball Bearing

Inspect the thrust faces of gears for scores,
scratches, and burrs. Remove such defects with a soft
Press ball bearing (1, Fig. 11) into final drive housing
honing stone.
cover and secure with snap ring (2).

Assembly

l--Bearing Cone 3-Final Drive Shaft

2-Bearing Cone

Fig. la-Final Drive Shaft Assembly

l-Bearing Cup 2--Oil Seal Heat bearing cones (1 and 2, Fig. 12) in oil not to
exceed 250°F (121 “C) before assembly. Press bearing
Fig. IO-Final Drive Housing Cover Oil Seal
cones onto final drive shaft (3) tight against shoulders.

Litho in U.S.A.
JD 750 Crawler Bulldozer Axles and Suspension System 2
TM- 1136 (Apr- 79) Axle Shaft, Bearings and Reduction Gears 0250-9

l--Sun Pinion Shaft 3-Snap Ring

2-Special Washer 4-Final Drive Gear

Fig. 14-Sun Pinion Shaft and Final Drive Gear

Position final drive gear (4, Fig. 14) in final drive

housing.

Install sun pinion shaft (1) through oil seal and roller
bearing, being careful not to damage oil seal.

Guide sun pinion shaft through final drive gear.

Install special washer (2) and secure with snap ring (3).

l-Bearing Cup 3-Final Drive Shaft with

2-Final Drive Shatt Bearings
Bearing Quill cl--Shims (as required)

Fig. 13-Final Drive Shaft Searing Quill

Press bearing cup (1, Fig. 13) tight against shoulder

in final drive shaft quill (2).

Install final drive shaft with bearings (3) into final

drive housing cover. Install shims (4), final drive shaft
bearing quill and secure with cap screws.

Adjust shims (4) to provide 0.004 to 0.006 inch (0.10

to 0.15 mm) endplay. Apply Loctite Thread and Lock
Sealer (Medium Strength) or an equivalent to tapped
holes in final drive housing cover and cap screws.
Tighten cap screws to 35 t 3.5 lb-ft (47 r 5 Nm) (5 &
0.5 kg-m).

Litho in U.S.A.
2 Axles and Suspension System JD 750 Crawler Bulldozer
0250-l 0 Axle Shaft, Bearings and Reduction Gears TM- 1136 (Apr-79)

Press bearing cone (1, Fig. 16) tight against

shoulder on planetary ring gear (2).

l-Bearing Cone a--Metal Face Seal

Fig. 15-Final Drive Housing Cover Bearing Cone

Install bearing cone (1, Fig. 15) on final drive hous-

ing cover against shoulder.

l-Bearing Cup 3-Metal Face Seal

P-Bearing Cup 4-Sprocket Frame

Fig. ll-Sprocket Frame Assembly

IMPORTANT: The bearing cup shoulders in

sprocket frame must be clean and free of nicks and
burrs before pressing in bearing cups.

Press bearing cups (1 and 2, Fig. 17) tight against

shoulders in sprocket frame (4).

Degrease counterbores in final drive housing cover

and sprocket frame before installing metal face seals
(2, Fig. 15 and 3, Fig. 17).

Install metal face seals. NOTE: A/ways install in

pairs-two new seals together or two used seals that
were previously paired. Refer to page 0250-13 for
l-Bearing Cone 2-Planetary Ring Gear
proper installation of sea/s.

Fig. 16-Planetary Ring Gear Searing Cone

Litho in U.S.A.
JD750 Crawler Bulldozer Axles and Suspension Systems 2
TM- 1136 (Apr- 79) Axle Shaft, Bearing and Reduction Gears 0250-11

INSTALLATION

l-Sprocket Frame 3-Retainer Plate

2-Planetary Ring Gear 4-Cap Screw (6 used)

Fig. 19-Sprocket Frame and Planetary

Ring Gear
l-Final Drive 2-Cap Screws
Housing Cover (22 used)
install sprocket frame (1, Fig. 19) using procedure
Fig. l&Installing Final Drive Housing Cover on page 0250-13, step 5.

Apply John Deere Loctite Plastic Gasket or an install planetary ring gear (2) aligning splines with
equivalent to final drive housing cover and final drive final drive housing cover.
housing bolting surface.
Secure planetary ring gear with retainer plate (3)
Install final drive housing cover (1, Fig. 18) and and cap screws (4). NOTE: Coat threads of cap screw
secure with cap screws (2). Tighten cap screws to 170 with John Deere Loctite Plastic Gasket or an equiva-
lb-ft (230 Nm) (24 kg-m). lent before installing.

Tighten cap screws to 170 ? 17 lb-ft (230 ? 23 Nm)

(24 ?C 2.5 kg-m).

Refer to page 0250-2 and install planet housing with

pinions and shafts.

Fill final drive housing with oil as recommended in

Section 1, Group V to fill plug level.

Litho in U.S.A.
2 Axles and Suspension Systems JD750 Crawler Biilldozer
0250-12 Axle Shaft, Bearings and Reduction Gears TM- 1136 (Apr-79)

METAL FACE SEALS

Inspection and Cleaning

After removal of sealing rings, inspect sealing ring
pattern to find out if seals can be reused. Refer to the
steps and figures below to determine the condition of
the metal rings.

266984

l-Metal Seal Ring 3-Inner Half of Sealing Face

2-Sealing Area 4-Center of Sealing Face
(shaded portion)

Fig. 21-A Poor Sealing Ring

T66983
The two drawings in Fig. 21 shows examples of poor
l-Metal Seal Ring 3-Outer Half of Sealing Face metal seal rings.
2--Sealing Area 4-Center of Sealing Face
(shaded portion) (Drawing A, Fig. 21) shows the sealing area (2)
within inner half of sealing face (3).
Fig. 20-A Good Sealing Ring

(Drawing B, Fig. 21) shows the sealing area (2) not

The following three steps are specifications which
concentric with I.D. and O.D. of metal seal ring (1).
determine a good sealing ring.

Clean the metal sealing rings as follows:

1 - The narrow, highly polished sealing area (2,
Fig. 20) must be within outer half of the sealing
Remove any corrosion or hardened material that
face (3).
may exist on the metal ring other than the sealing area.
Use a scraper and/or any stiff bristled fiber brush to
2 - The sealing area (2) must be uniform and con-
remove the foreign material from the surface.
centric with the I.D. and O.D. of metal seal ring
(1). Wash the metal sealing rings with a non-flammable
solvent to remove all oil and wipe dry. Use the lint free
3 - The sealing area must not be chipped or
wiper furnished in the new seal package to remove all
scratched in any way.
traces of oil or grease from all surfaces.

NOTE: If metal rings appear to be useable, keep

the two metal face seals together as matched sets. If
ihe metal rings are not within proper specifications, DO
NOT rebuild the seal; use a completely new seal.

Litho in U.S.A.
JO750 Crawler Bulldozer Axles and Suspension Systems 2
TM- 1136 (Apr- 79) Axle Shaft, Bearings and Reduction Gears 0250-13

Proper Installation of Metal NOTE: Thoroughly clean the counterbores in the

Face Seals final drive housing cover and sprocket frame before
installing the seals.
If metal sealing rings are acceptable for re-build,
new rubber seals MUST be installed each time final
Install the seal half assemblies into the final drive
drive is disassembled.
housing cover and sprocket frame in their respective
location as follows:
After sealing rings have been cleaned and dried,
assemble the rubber seal (1, Fig. 22) onto the metal
1. Insert the sealing rings into the counterbores, so
seal rings (2). Make sure the seal is tight against the
that the major diameter of the rubber seals squarely fits
sealing ring shoulder flange all around. If new rings and
and is held in place under its own resistance.
seals are installed, make sure rubber seals are tight
against the metal flange also. Remove plastic band
2. Apply equal pressure using the two thumbs and
retainer from new seals just before installation.
two middle fingers at four equally spaced points on the
sealing ring face. The seal assembly must “pop” down
Be sure the special dirt excluder lips (3) are outside
into place, so that the rubber seal is tight against the
of the metal seal rings.
seal bore shoulder. Use a blunt end instrument inside
the retention barb (4, Fig. 22) to make sure seal is tight
against the shoulder. Be careful not to tear the reten-
tion barb.

3. Wipe both sealing ring faces dry with lint free

wipers.

4. Apply a light finger spread coating of oil, as used

in the final drive, to the shiny sealing area on metal seal
rings.

5. When the sprocket frame is installed and the two

sealing rings touch each other, the axial pressure must
be maintained, compressing the seal until the plane-
b 2 tary ring gear is installed and the cap screws tightened.
NOTE: If sealing ring pressure is relieved before the
planetary ring gear is secured, the rubber seals will
disengage from the metal rings. If this occurs, you must
T6696 15 remove the seals from the bores, push the rubber seals
l--Rubber Seal 3-Dirt Excluder Lip
against the sealing ring shoulder flange and then do
2-Metal Seal Ring e-Retention Barb the installation over.

Fig. 22-Metal Face Seals

Litho in lJ,S.A.
2 Axles and Suspension Systems JD750 Crawler Bulldozer
0250-14 Axle Shaft, Bearings and Reduction Gears TM- 1136 (Apr- 79)

Litho in U.S.A.
JO750 Crawler Bulldozer Axles and Suspension System 2
TM-1 136 (Nov-78) Specifications and Special Tools 0299-l

Group 0299
SPEClFldATlONS AND SPECIAL TOOLS
DRIVE AXLE HOUSING
SPECIFICATIONS AND TORQUE VALUES
1 - Final drive housing to
frame cap screws . . . . . . . . (D-grade) 300 lb-ft
(407 Nm)
(41 kg-m)
(F-grade) 425 lb-ft
(576 Nm)
(59 kg-m)

Fig. I-Final Drive Housing

Lifbo in U.S.A.
2 Axles and Suspension System JD750 Crawler Bulldozer
0299-2 Specifications and Special Tools TM- 1136 (Nov-78)

AXLE SHAFT, BEARINGS AND REDUCTION GEARS

SPECIFICATIONS AND TORQUE VALUES

1 - Planet pinion carrier

cover cap screws. . . . . . . . . . . . . . . . 170 lb-ft
;230 Nm)
(24 kg-m)

Fig. PPlanetary Housing

1 - Final drive shaft

end play.. . . . . . . . . . . . . . . . . 0.004 to 0.006 in.
(0.10 to 0.15 mm)

2 - Final drive shaft bearing

quill cap screws , . . . . . . . . . . . . . . . . . . . 35 lb-ft
(47 Nm)
(5 W-4

2’62213N

Fig. 3-Final Drive Shaft

Litho in U.S.A.
 -__
JO750 Crawler Bulldozer Axles and Suspension System 2
TM-1 136 (Nov-78) Specifications and Special Tools 0299-3

AXLE SHAFT, BEARINGS AND REDUCTION GEARS

SPECIFICATIONS AND TORQUE VALUES
1 - Sprocket frame retainer
,‘. . plate cap screws . . . . . . 170 lb-ft
/ (230 Nm)
/ 0).
/ (24 kg-m)
Q&J j$&
//
..
‘1 p”$ ‘I 1 2 - Final drive housing
-1 ,
‘. cover cap screws. . . . .. .... . 170 lb-ft
\ \,’ ~*J@@
(230 Nm)
\ \ (24 kg-m)
f -.

T62214N

Fig. 4-Final Drive Housing Cover

DRIVE AXLE HOUSING

SPECIAL TOOLS

Essential Tools

Tool Tool No. Use

JD-324 To hold transmission in position

when removing final drive hous-
ing.

Fig. ITransmission Motor Holding Plate

Litho in U.S.A.
2 Axles and Suspension Systems JD750 Crawler Bulldozer
0299-4 Specifications and Special Tools TM-1 136 (Nov-78)

DRIVE AXLE HOUSING AND SUPPORT

SPECIAL TOOLS-Continued

ssential Tools-Continued

Tool Tool No. Use

JD-326 To align splines on motor with final

drive shaft splines.

Fig. b-Transmission Motor Spline Alignment Tool

:onvenience Tools
Tool No. USe

1 - JD-347-1 To remove or install final drive as-

sembly. Includes safety chain.

2 - JD-347-2 Used with JD-347-1 for added lift-

ing clearance around sump tanks.

Fig. 7-Final Drive Lifting Tool

itho in U.S.A.
JO750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Controls 0315-l

Section 3
TRANSMISSION
CONTENTS OF THIS SECTION

Page Page
GROUP 0315 - CONTROLS GROUP 0325 - INPUT DRIVE SHAFTS AND
General Information ................. . 0315-3 U-JOINTS
Steering Linkage .................... .. 0315-4 General Information . . . . . . 0325-l
Removal ......................... . 0315-4 Removal . . . . . . . .; 0325-l
Repair ........................... . 0315-6 Repair . . . . . .. . . . 0325-2
Installation. ....................... . 0315-6 Installation. . . . . .. . . . 0325-2
Forward and Reverse Speed Control . . .. 0315-a
General Information ............... .. 0315-8 GROUP 0360 - TRANSMISSION HYDRAULICS
Control Head ..................... . 0315-g Hydrostatic Transmission. ... . . 0360-l
Removal ....................... . 0315-g General Information .......... . 0360-l
Repair ......................... 0315-g Removal .................... 0360-2
Installation ..................... : b315-10 Repair ...................... 0360-3
Control Linkage ................... . 0315-11 Installation. .................. 0360-3
Removal ....................... . 0315-11 Transmission Pump .......... 0360-5
Repair ......................... 0315-11 General Information ........ 0360-5
Installation ..................... . 0315-11 Removal .................. 0360-5
Automatic Control Valve Variable Disassembly ...............
Orifice Linkage. ..................... 0315-11 Inspection ................. : ‘0360-l
0360-78
Removal ......................... 0315-l 1 Assembly ................. 0360-l 9
Repair ........................... . 0315-l 1 Installation ................ 0360-25
Installation. ....................... 0315-11 Charge Pump ............. 0360-26
Speed Control Support. .............. . 0315-13 General Information ...... 0360-26
Removal .......................... . 0315-13 Removal ................ 0360-26
Repair ........................... . 0315-13 Disassembly ............ 0360-26
Installation. ....................... 0315-13 Inspection. .............. . 0360-26
Automatic Control Valve Shutoff Assembly ............... 0360-27
Valve Control ....................... 0315-14 Installation .............. 0360-27
Removal ......................... 0315-14 Displacement Control Valve. 0360-28
Repair ........................... . 0315-14 Removal ................ 0360-28
Installation. ....................... . 0315-14 Repair .................. 0360-28
Return-To-Neutral Linkage ........... . 0315-15 Inspection. .............. 0360-31
Removal ......................... 0315-15 Assembly ............... 0360-31
Repair ........................... . 0315-15 Installation .............. 0360-32
Installation. ....................... 0315-15 Bypass Valve ................ 0360-33
Removal .................. 0360-33
Disassembly. .............. . 0360-33
Assembly ................. 0360-34
Installation ................ . 0360-34

Litho in U.S.A.
 3 Transmission JD750 Crawler Bulldozer
0315-2 Controls TM-l 136 (Nov-78)

CONTENTS OF THIS SECTION-Continued

Page Page
GROUP 0360 - TRANSMISSION HYDRAULICS GROUP 0360 - TRANSMISSION HYDRAULICS
-Continued -Continued
Hydrostatic Transmission-Continued Transmission Reservoir ................ 0360-89
Transmission Motor ................. 0360-35 General Information ................. 0360-89
General Information ............... 0360-35 Removal ........................... 0360-89
Removal ......................... 0360-35 Inspection .......................... 0360-89
Inspection ........................ 0360-46 Installation .......................... 0360-89
Assembly ........................ 0360-46 Transmission Filter .................... 0360-90
Installation ....................... 036051 General Information ................. 0360-90
Displacement Control Valve ........ 0360-52 Removal ........................... 0360-90
Removal. ...................... 036052 inspection .......................... 0360-90
Repair. ........................ 0360-52 Installation. ......................... 0360-90
Inspection. ..................... 0360-53
Assembly ...................... 0360-53 GROUP 0370 - CLUTCH DISCONNECT

q
2,
Installation .....................
Manifold Valve Assembly ..........
Removal. ......................
036053
0360-55
0360-55
Controls
AND CONTROLS

General Information. .................. 0370-l

Disassembly ................... 0360-55 Removal. ............................ 0370-l
Inspection. ..................... 0360-55 Repair. .............................. 0370-l
Assembly ...................... 036055 Installation ........................... 0370-l
Installation ..................... 0360-56 Clutch Elements
Transmission Control Valve ............ 0360-57 General Information. .................. 0370-4
General Information ................. 0360-57 Removal. ............................ 0370-4
Removal ........................... 0360-58 Repair. .............................. 0370-4
Disassembly. ....................... 0360-59 Installation ........................... 0370-6
Repair ............................. 0360-71
Assembly .......................... 0360-72 GROUP 0399 - SPECIFICATIONS AND
Installation .......................... 0360-84 SPECIAL TOOLS
Oil Cooler ............................ 0360-85 Specifications and Torque Values
General Information ................. 0360-85 Input Drive Shaft and U-Joints ......... 0399-l
Removal ........................... 0360-85 Transmission Hydraulics ............... 0399-l
Inspection ................... I ...... 0360-85 Clutch Disconnect and Controls ....... 0399-10
Installation. ......................... 0360-85 Special Tools
Oil Cooler Bypass Valve ............... 0360-86 Transmission Hydraulics. ............. 0399-l 1
General Information ................. 0360-86 Clutch Disconnect and Controls ....... 0399-16
Removal ........................... 0360-86
Disassernbly ........................ 0360-86
Inspection .......................... 0360-86
Assembly .......................... 0360-86
Installation. ......................... 0360-86
Transmission Operating Pressure Valve 0360-87
General Information ................. 0360-87
Removal ........................... 0360-87
Disassembly. ....................... 0360-87
Inspection .......................... 0360-87
Assembly .......................... 0360-88
Installation. ......................... 0360-88

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- I 136 (Feb-77) Controls 03153

Group 0315
CONTROLS
GENERAL INFORMATION
The transmission controls include the controls for
steering, direction, and automatic speed control.
The steering pedals, or levers, are linked to the two
levers (1 and 2, Fig. 1) at the front of the transmission
control valve (3).
The forward and reverse speed control lever (2, Fig.
2), located on the left console in the operator’s station,
is linked to the FNR valve lever (5, Fig. 1) on the left
side of the transmission control valve (3).

The throttle lever (3, Fig. 2) located on the left

console in the operator’s station, is linked to the auto-
matic control valve variable orifice lever (4, Fig. 1) and
to the engine speed cable (6).

The automatic control valve shut off handle (4) is

located on the left console between the throttle lever
and the forward and reverse speed control lever. This
cable shuts off the automatic control valve and allows
the transmission to be operated during cold weather
warm-up.
l-Neutral Lock Lever 4-Automatic Control Valve
2-Forward and Reverse Shut off Handle
Speed Control Lever
.
3-Throttle Lever

Fig. Z-Transmission Control Levers

l-L.H. Steering Valve 4-Automatic Control

Lever Valve Variable
2-R-H. Steering Valve Orifice Lever
Lever 5-FNR Valve Lever
3-Transmission Control 6-Engine Speed Cable
Valve

Fig. 1-Transmission Controls

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0315-4 Controls TM- 1136 (Feb-77)

STEERING LINKAGE
REMOVAL

Lever Steering Upper Linkage Steering Lower Linkage

The lever steering upper linkage consists of the The linkage from the spring shaft (22, Fig. 4) to the
steering arm (2, Fig. 3), upper link (3) and idler arm (4) transmission control valve (32) is the same for both
connected to the lever steering support (8). A ball joint lever and pedal steering.
(6) connects the lever steering support shaft (5) to the
steering arm lever (7). l-Bell Crank Support 15-Ball Joint (4 used)
Bracket 16-Jam Nut (4 used)
2-Set Screw (4 used) 17-Steering Valve
8-Nut (4 used) Control Rod (2 used)
4-Bell Crank Shaft 18-Shaft Bearing (6 used)
(2 used) 14-Dowel Pin (2 used)
j-Bell Crank Arm (4 used) l&-Sleeve (2 used)
6-Nut (12 used) Pl-Steering Support
( -242796) 22-Spring Shaft (2 used) , 1 5
Lock Nut (12 used) 28-Ball Joint (2 used)
(242797- ) 24-Spring (2 used)
7-Washer (8 used) 26-Retainer (4 used) i
( -242796) 26Snap Ring (4 used) \ i
&-Cap Screw (2 used) 27-Sleeve Stop (2 used)
i.:
g-Washer (4 used) 28-Set Screw (2 used)
ltl-Ball Joint (2 used) 29-Spring Stop (2 used) f
ll-Roller Bearing (4 used) 38-Spring (2 used)
12-Cap Screw (6 used) 31-Steering Pedal or
18-Washer (2 used) Arm (2 used)
14-Bell Crank Support 32-Transmission Control
(2 used) Valve

l-Steering Lever 6-Support Shaft Legend for Fig. 4-Steering Lower Linkage
2-Steering Arm 6-Bali Joint (I?.H. Linkage)
8-Upper Link 7-Steering Arm Lever
4-Idler Arm &Lever Steering Support

Fig. 3-Lever Sfeering Upper Linkage

(Right-Hand Controls)

Remove hood.

Disconnect necessary linkage to remove defective

parts.

Pedal Steering Upper Linkage

The pedal steering upper linkage consists of the
steering pedals connected to the pedal steering sup-
port. A ball joint connects the pedal steering support
shaft to the steering pedal lever.

Remove floor boards.

Disconnect necessary linkage to remove defective

parts.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-1 136 (Nov-75) Controls 0315-S

u/22
fl ,23

2542
m-26

2451901

Fig. I-Steering Lower Linkage (FM. Linkage)

Litho in U.S.A.
3 Transmission JD 750 Crawler Bulldozer
0315-6 Controls TM-1 136 (Nov-76)

Remove floor boards.

Disconnect necessary linkage to remove defective

parts.

REPAIR
Inspect all connecting rods and links to determine if
they are bent or inoperable.

Inspect all bushings, needle bearings and ball joints

for freedom of movement.

Replace parts as necessary.

INSTALLATION
Install parts using Figures 4, 5, and 6 as a guide. LEVER
STEERING
SUPPORT AND
After installation refer to Group 9026, adjustment SHAFT
section, and do the following procedures: T44721

Procedure 14 - Steering valve stop adjustment l-Needle Bearing j-idler Arm

(4 used) GRetaining Ring
Procedure 15 - Steering linkage adjustment
2-Upper Link 7-Needle Bearing
Procedure 16 - Steering neutral stops adjustment 3-Pivot Shaft (2 used) (4 used)
4-Spring Pin (2 used) 8-Steering Arm
Install floor boards and hood.
Fig. S-Lever Steering Linkage
(R. t-t. Lever)

Litho in U.S.A.
JD 750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-75) Controls 0315-7

Q3
T44722

l-Spring 4-Shaft 7-Needle Bearing (4 used)

2-Groove Pin S-Steel Ball (5 used) 8-R.H. Steering Pedal
3-Groove Pin S-Washer 9-L.H. Steering Pedal

Fig. g-steering Pedals and Shaft

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0315-8 Controls TM- 1136 (Nov-75)

FORWARD AND REVERSE Sl?EED CONTROL

GENERAL INFORMATION in the left console connected by ball joint rods to the
front control arms in the speed control support to the
The forward and reverse speed control consists of
cross shaft to FNR speed control lever on the trans-
the forward and reverse speed control head and lever
mission control valve.

Q18
32

-16

-19

-21

25 \

l-Cap Screw (4 used) 1 I-O-Ring 20-Adapter Cam 30-Nut (4 used)

P-Lock Washer (3 used) 12-Bearing Roller tl-Cap Screw 31-Forward and Reverse Speed
3-Cap Screw (2 used) 13-Neutral Lock Lever 22-Washer Control Head
4-Control Head Bracket 14-Knob 23-Bearing 32-Engine Speed Control
5-Cap Screw 15-Yoke 24-Trip Lever Assembly Head
G-Machine Screw 1GNut 25-Pivot %-Throttle Lever Linkage
7-Lock Washer (2 used)- 17-Forward and Reverse 26Plug 34-Forward and Reverse
8-Nut (2 used) Speed Control Lever 27-O-Ring Speed Control Lever
g--Starter Safety Swhch 1 &-Knob 2&Spring Linkage
it&Washer 14-Bearing Z&--Steel Ball 35-Return to Neutral Cable

Fig. 7-Forward and Reverse Speed Control Head Removal

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Apt-- 79) Controls 0315-9

CONTROL HEAD

Removal Remove cap screws (1) to separate forward and

reverse speed control head (31) from bracket (4).
The forward and reverse speed control head is
located on the inside of the control head bracket in the Remove facings (2, Fig., 8) and separator plate (3),
left-hand console. facings (2), neutral lock plate (4) and another set of
facings (2).
Remove the console cover.
Remove pressure plate (5) Belleville springs (6),
Remove the throttle lever, forward and reverse
and plate (7).
speed control lever, and the neutral lock lever.
Remove shaft (1) and oil seal (9).
Disconnect the throttle lever linkage (33, Fig. 7) the
forward and reverse speed control linkage (34) and the Remove plug (26, Fig. 7), spring (28), and steel ball
return to neutral cable (35). C-3.
Remove the pivot (25) from the trip lever assembly
Repair
(24).
Inspect neutral lock plate (4, Fig. 8) for broken
Remove three cap screws (3 and 5) that mount the
corners on the neutral slot.
control head bracket (4) and remove the control head
assembly. Inspect Belleville springs (6) pressure plate (5), and
facings (2) for wear.
Remove pipe plug (11, Fig. 8) and drain oil from
control head. Inspect bore for steel ball (29, Fig. 7) to insure ball
moves freely in bore.

\
/
L- T45192N

l-Shaft 7-Plate
2-Facing (6 used) &Dowel (2 used)
3-Separator Plate g-Oil Seal
4-Neutral Lock Plate lO-Forward and Reverse Speed Control Head Housing
6-Pressure Plate 1 l-Pipe Plug
GBelleville Spring (3 used) 12-W Screw (3 used)

Fig. b-forward and Reverse Speed Control Head Components

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
031510 Controls TM- 1136 (Apr- 79)

Installation 6. install neutral lock plate (4) and second set of

facings.
Assemble forward and reverse speed control head
per Figs. 7 and 8. 7. Install separator plates (3) and third set of fac-
ings.
1. Apply Loctite Sealant to tapped holes of forward
and reverse speed control housing and assemble 3 set 8. Install neutral start switch and washer. I
screws (12, Fig. 8) flush with the inside wall of the
9. Install detent ball (29, Fig. 7), spring (28) and
housing.
plug (26) with O-ring.
2. Lubricate and install shaft (1) into housing.
Fill control head with same type of oil used in trans-
3. Install plate (7). mission to pipe plug (11, Fig. 8) level. Install plug.
Capacity is 0.1 gal. (375 mL).
4. Install 3 Belleville springs (6), alternating the dish
of the springs, with the first spring installed with the Install control head assembly Loctited to bracket in
inner diameter away from seal. left console and tighten cap screws.

5. Install pressure plate (5) and one set of facings Install throttle lever, forward and reverse speed
(2);one on each dowel. control lever and neutral lock lever.

Install pivot in trip lever assembly.

T45193N

l-Nut (4 used) ( -242796) 7-Rod Assembly

Lock Nut (4 used) (242797- ) &Nut
2-Lock Washer (4 used) ( -242796) 9-Set Screw
3-Gap Screw (4 used) 1O-Adapter Cam
4-Ball Joint (4 used) 1l-Control Support
S-Nut (4 used) 12-Gross Shaft With Lever
6-Rod Assembly

Fig. 9-Forward and Reverse Speed Control Linkage

Litho in U.S.A. ’
JD 750 Crawler Bulldozer Transmission 3
TM- 1136 (Mar-78) Controls 0315-11

Connect throttle lever linkage, forward and reverse AUTOMATIC CONTROL

speed control linkage and return-to-neutral cable.
VALVE VARIABLE
Refer to adjustment section, Group 9026, and do the ORIFICE LINKAGE
following procedures:
The throttle lever controls the engine speed control
Procedure 3 - FNR speed control lever linkage linkage and the automatic control valve variable orifice
neutral adjustment linkage.

Procedure 4 _ Engine speed and transmission See Section 18, Group 1824, for removal and repair
control valve synchronization of the engine speed control linkage.

Adjust forward and reverse speed control head set The automatic control valve variable orifice linkage
screws (12, Fig. 8) evenly. consists of the linkage from the cross shaft to the
transmission control valve.
When set screws are tightened properly, a force of 6
+ 1 lb. (27 ? 5 N) (3 + 0.5 kg) is required to move the REMOVAL
lever. Measure the force with a spring gauge hooked
Remove floor boards.
right below the knob.
Refer to Fig. 11 and disconnect necessary linkage to
Install console cover.
remove defective parts.

CONTROL LINKAGE REPAIR

Inspect linkage for worn or bent parts.
Removal
Remove console cover and floor boards. Refer to Replace parts as necessary.
Figures 9 and 10 and disconnect necessary linkage to
remove defective parts. INSTALLATION
Install parts using Fig. 11 as a guide.
Repair
Inspect linkage for bent or worn parts. Replace as After installation, refer to adjustment section, Group
necessary. 9026, and do Procedure 4 - Engine speed and trans-
mission control valve synchronization.
Installation
If the cross shaft support (18, Fig. 11) has been
Install parts using Figures 9 and 10 as guides.
removed, the following procedures must be performed.

After installation, refer to adjustment section, Group

Procedure 3-FNR Speed control lever linkage neu-
9026, and do Procedure 3 - FNR speed control lever
tral adjustment.
linkage neutral adjustment.
Procedure 4-Engine speed and transmission control
If the cross shaft support (18, Fig. 11) has beeh
valve synchronization.
removed, the following procedures must be performed.

Install console cover and floor boards.

Procedure 3-FNR speed control lever linkage neu-
tral adjustment.

Procedure 4-Engine speed and transmission control

valve synchronization.

Install console cover and floor boards.

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
031512 Controls TM- 1136 (Mar-78)

T45194N

l-Nut (2 used) ( -242796) %-Bail Joint (2 used) 7-Cross Shaft With Lever
Lock Nut (2 used) (242797- ) 4-Nut (2 used) OTransmission Control Valve
2-Lock Washer (2 used) S-Rod Assembly 9-FNR Speed Control Lever
( -242796) S-Cap Screw (2 used) .

Fig. lo-FNR Speed Control Lever Linkage

T45195N

l-Nut (4 used) %-Cap Screw (3 used) 9-Lever (2 used) 1 &-Rod Assembly

( -242796) 4-Nut (4 used) 1 O-Lever %-Spacer (with cab)
Lock Nut (4 used) 9--Bail Joint (3 used) Ii-Cross Shaft 17-Transmission Control
(242797- ) &-Rod Assembly 12-Needle Bearing (2 used) Valve
a--Lock Washer (4 used) 7-Set Screw (3 used) Xi-Engine Speed Cable M-Cross Shatt Support
( -242796) 9-Nut (3 used) M-Bail Joint 19--Control Support Rear Arm

Fig. Il-Automatic Control Valve Variable Orifice Linkage

bitho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Feb-77) Controls 031513

SPEED CONTROL SUPPORT Replace parts as necessary.

The speed control support is located on the floor of INSTALLATION

the left console.
Install control support assembly in left console with
stamped word “FRONT” on cover toward front of the
REMOVAL
unit. Tighten cap screws.
Remove console cover and floor boards. -.
Connect throttle lever upper and lower linkage.
Disconnect the throttle lever, upper and lower link-
age and the forward and reverse speed control lever Connect forward and reverse speed control lever,
upper and lower linkage. upper and lower linkage.

Remove four cap screws. Refer to adjustment section, Group 9026, and do the
following procedures:
Remove control support assembly.
Procedure 3 - FNR speed control lever linkage
Disassemble control support assembly using Fig. 12 neutral adjustment
as a guide.
Procedure 4 - Engine speed and transmission
REPAIR control valve synchronization
Inspect bearings (5, Fig. 12) for wear.
Install floor boards and left console cover.

jj FORWARD AND

LINKAGE

ENGINE SiEED
CONTROL LINKAGE f
T44744

l-Set Screw (4 used) 4-Steel Plug (2 used) 7-Lock Washer (4 used) 10-Forward and Reverse
2-Nut (4 used) 5-Bearing (4 used) S-Control Support Cover Speed Control Shaft
3-Lever (2 used) 6-Cap Screw (4 used) g-Engine Speed Shaft 11-Lever (2 used)

Fig. IFSpeed Control Support

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 3 Transmission JD750 Crawler Bulldozer
031514 Controls TM-1136 (Feb-77) ’

AUTOMATIC CONTROL VALVE SHUTOFF VALVE CONTROL

I
REMOVAL 1. Install nut (15, Fig. 13) on automatic control valve
support rod end.
Remove floor boards and left console cover.
2. Install yoke (10) onto valve rod end and adjust
Refer to Fig. 13 and disconnect linkage to remove yoke so that there is 318 inch (9.5 mm) thread from the
defective parts. threaded end of the yoke to the thread run-out on the
d. valve rod end.
i-
REPAIR
3. Assemble lever (11) to yoke (10) with pin (8) and
Inspect cable for binding. cotter pin (7).

4. Attach cable support (12) to the transmission

Inspect bell crank for wear.
control valve.
WC_‘I
:4z-. INSTALLATION 5. Attach lever (11) to cable support (12).
-4
Install parts using Fig. 13 as a guide.

CONTROL VALVE

T43374

l-Locking Handle 6-Washer Ii-Bell Crank Lever

2--Machine Screw 7-Cotter Pin (2 used) 12-Gable Support
3-Positive Lgcking Cable S-Yoke Pin (2 used) K&Washer (2 used)
4-Grommet g-Shoulder Screw 14-Nut
5-Clamp 1 O-Yoke 1 cut

Fig. Id-Automatic Control Valve Shutoff Valve Control

Litbo in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-l 136 (Nov-78) Controls 0315-15

6. Install positive lock cable (3) and adjust cable

yoke end (10) such that the lever bottoms out at the
transmission control valve just before the handle (1)
bottoms out on the LH console.

18
Refer to adjustment section, Group 9026 and do
Procedure 18 - Automatic control valve shutoff cable
adjustment.

Install floor boards and left console cover.

RETURN-TO
NEUTRAL LINKAGE
The return-to-neutral cable goes from the brake
pedal shaft arm to the trip lever assembly in the left
console.

REMOVAL
T48767N
Remove left console cover and floor boards.
l--Spring Clip 1 l-Nut
Remove cable using Fig. 14 as a guide. l-spring 12-Cap Screw
3-Lock Washer 13-Ball Joint
If the trip lever assembly must be removed, refer to ( -242796) 14-Special Washer
4-Gap Screw 15-Trip Lever Assembly
forward and reverse speed control head removal, this
f&Cam Adapter l&-Bearing
group. 6-Gap Screw 17-Pivot
7-Gap Screw l&Brake Pedal Shaft Arm
&Ball Joint 19-Nut ( -242796)
9-Nut Lock Nut (242797- )
lO-Control Cable

Fig. 14-Return-to-Neutral Cable

REPAIR
Inspect cable for ease of operation.

Inspect trip lever bearing for wear.

Replace parts as necessary.

INSTALLATION
Install parts using Fig. 14 as a guide.

Refer to adjustment section, Group 9026 and do

Procedure 17 - Return-to-neutral cable adjustment.

If brake pedal shaft arm has been replaced or

moved, do Procedure 2 - Brake valve cable adjust-
ment.

Install floor boards and left console cover.

bitho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0315-16 Controls TM-1 136 (Nov-78)

Litho in U.S.A.
JD 750 Crawler Bulldozer Transmission 3
TM- 1136 (Feb-77) Input Drive Shafts and U-Joints 0325-l

Group 0325
INPUT -DRIVE SHAFTS- AND U-JOINTS
GENERAL INFORMATION
The drive shaft is composed of three major parts: the
drive end, the main tube and the driven end.

A universal joint is located at each end of the drive

shaft and is retained by clips. Each joint has a grease
fitting for lubrication.

The drive end universal has a flange which bolts to

-.. .
the drive hub.

The drive shaft is torsionally dampened to absorb

drive line shock and vibration.

Four rubber doughnuts are located between the

El
main tube and the two end shafts. These doughnuts
are bonded to both the main tube and the ends. These
are non-serviceable parts because they are com-
pressed inside the tube.

The driven hub is connected to the drive shaft by

Fig. 1-Transmission Drive Shaft
U-bolts.
Discqnnect the linkage from the equipment control
The hub itself is keyed to the hydrostatic transmis-
valve.
sion input shaft. A washer and nut are used to retain
the hub to the shaft.
Remove nuts (1, Fig. 2) from the U-bolts (3) and
slide the drive shafts (7) from the output shafts in the
REMOVAL splitter housing.
To ,remove the drive shafts, place a jack under the
rear bottom guard. Remove cap screws (12) from the yoke and remove
the drive hub.
Remove attaching cap screws. Lower jack and slide
the guard out the back of the unit. NOTE: Before the removal of the journal and bear-
ing kit (6), apply John Deere Multi-Purpose Grease or
Refer to Fig. 2 for disassembly and assembly of the equivalent at the grease fittings.
drive shaft.
Remove all snap rings from the universal cross and
by using a driff, tap out the bearing assemblies.

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0325-2 Input Drive Shafts and U-Joints TM- I 136 (Feb- 77)

REPAIR
8

T48745N

l-Nut (8 used) 7-Drive Shaft (2 used) 13-Bearing Cap Screw

2-Lock Washer 18 used) &Drive Hub (2 used) (8 used)
3-U-Bolt (4 usi) . g-Sealing Ring (2 used) 14-Lock Washer (8 used)
4-Lock Nut (2 used) lo--Washer (8 used) 1%Bearing Strap Retainer
G-Driven Hub (2 used) l&Cap Screw (8 used) (4 used)
8-Journal and Bearing l2-Key (2 used) 18-Driven Hub (2 used)
(4 used)

fig. PRemoval and Installation of Drive Shaft

Remove the yokes to inspect the universal joints, INSTALLATION

beapgs and seals.
Refer to Fig. 2.
’ i
Inspection of universal joints and bearings requires
NOTE: install universal crosses (6) and drive shafts
the removal of the bearing retainer straps (16, Fig. 2).
(7) so that a// the grease fittings point the same direc-
tion to facilitate greasing.
Note the lack of or excessive amount of lubricant or
hardened grease plugging lubrication passages in the Install the journal and bearing (6) in the yokes of the
universal joints. drive shafts; insert the bearing assemblies and snap
rings.
Clean and inspect the drive hub (9) and the driven
hub (17). Pack drive hub spline with JDM J17A Anti-seize
Compound before inserting the sealing rings (10).
Inspect all bearings and hardware for excessive
wear. Tighten cap screws (12) from the drive shaft yoke to
the drive hub.
Note lack of or excessive amount of lubricant. Re-
place parts as needed.
Slide drive shaft and drive hub onto the output shaft
of the splitter housing.

Litho in U.S.A.
 JD750 Crawler Bulldozer Transmission 3
TM- 1136 (A pr- 79) Input Drive Shafts and U-Joints 0325-3

NOTE: Make sure grease fittings on the two drive After installation, apply John Deere Multi-Purpose
shafts line up; either both up or both down. Grease or equivalent to the universal joints slowly until
grease appears at each bearing cup.
( Insert key (12, Fig. 2) into the drive hub and slide it
onto the hydrostatic input shaft. Tighten lock nut (4) to
300 lb-ft (407 Nm) (41 kg-m).

Connect the loose end of the drive shaft to the driven

hub by tightening the U-bolts and bearing straps.

Tighten U-bolt nuts (1) to 22 lb-ft (30 Nm) (3 kg-m).

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
03254 Input Drive Shafts and U-Joints TM- I 136 (Apr- 79)

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-75) Transmission Hydraulics - 0360-l

Group 0360
TRANSMISSION HYDRAULICS
HYDROSTATIC TRANSMISSIONS
GENERAL INFORMATION

l-Charge Pump 6-Pump Displacement Control Valve 1 l-Manifold Valve

2-Pump Displacement Control Valve 7-R.H. Transmission Pump 12-Manifold Valve
3-L.H. Transmission Pump 8-Charge Pump 13-Motor Displacement Control
4-L.H. Bypass Valve 9-R.H. Transmission Motor Valve
5-R.H. Bypass Valve 104lotor Displacement Control Valve 14-L.H. Transmission Motor

fig. /l-Right and Left Transmissions

,
There are a right transmission and a left transmis- Although the two transmissions are similar, there are
sion. Each transmission consists of a reversible vari- some basic differences. These differences are pri-
able displacement axial piston pump and a variable marily in the mounting of the pump to the motor
displacement axial piston motor. Both transmissions through the use of different pump and motor end caps
are controlled by a common control valve. and in the locating of the components on the housings.
The left transmission charge pump also houses the
transmission control valve charge pump.

Litho in-U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-2 Transmission Hvdraulics TM- 1136 (Nov- 75)

IMPORTANT: Although there are many compo- Remove fuel lines from bulkhead fittings and plug
nents of this transmission that are similar to other lines and fittings with metal caps. Set lines to one side.
hydrostatic pump-motor combinations, DO NOT
INTERCHANGE parts from other hydrostatic units Loosen eight cap screws and remove rear support
with this hydrostatic transmission. Refer to your plate.
parts catalog and order only parts designated
there. Remove seat and remove batteries.

Cleanliness Remove battery tray, seat latch, and battery tray

support.
Throughout this section there &I be continual notes
referring to the cleanliness that must be maintained
Drain hydrostatic sump.
while servicing this transmission. Contamination of any
type within this transmission will shorten the expected
NOTE: If hydrostatic fluid is to be reused, have a
life of its parts.
clean 25 gallon (95 I) container available. Clean con-
tainer with diesel fuel and dry with compressed air.
Before removing the transmission, remove PTO
access cover and access cover below fuel tank and
Mark all lines and fittings on transmission and bulk-
thoroughly clean the transmissions. Either steam clean
head plate. Disconnect all lines from transmission.
or wash with diesel fuel.
Disconnect lines from bulkhead plate. Cap all lines and
all fittings with clean caps. Set lines to one side.
IMPORTANT: Use only diesel fuel to clean parts
on this transmission. Solvents are damaging to the
Remove transmission operating pressure valve and
internal components of the transmission.
fitting from left transmission. Cap fittings and plug port
in transmission.
REMOVAL
Turn battery disconnect off. Remove bottom access cover.

Remove cap screws from rear of canopy or cab. Disconnect drive shaft from transmission by remov-
Also remove two cap screws from pivot area of canopy. ing two U-bolts from universal joint.

Loosen retaining clamp on muffler exhaust tube and If unit is equipped with winch, remove winch drive
remove tube. shaft.

If crawler is equipped with a cab, refer to Group If left transmission is being removed, drain the
1810. equipment sump and disconnect the sump suction
hose from the sump. Move hose to one side.
Pivot canopy or cab forward and reinsert two pivot
cap screws to lock canopy in forward position. NOTE: If hydraulic fluid is to be reused, have a
clean 25 gallon (95 I) container available. Clean con-
Remove remaining cap screws holding fuel tank to tainer with diesel fuel and dry with compressed air.
tank support.
Attach overhead hoist, minimum capacity one ton
Disconnect fuel line and fuel return line. Plug lines (907 kg), to the eyebolt (1, Fig. 2) on the transmission.
and fitting with clean plugs.
Remove the six cap screws holding the transmission
Screw two eyebolts into tapped holes on top of fuel to the final drive housing. The top three cap screws go
tank and support tank with overhead hoist. through the final drive housing into the transmission
housing. The bottom three cap screws go through
Slide fuel tank away from rear support plate and transmission housing into final drive housing.
remove. Set tank to one side.
Slide the transmission off final drive output shaft.

Remove transmission (Fig. 2) and mount on floor

stand, JD 327, see Group 0399.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3 ,t
TM- 1136 (Apr- 79) Transmission Hydraulics 0360-3

If unit is equipped with winch, install winch drive

shaft.

Connect drive shaft to universal joint.

Reconnect all lines and fittings. Replace-O-rings as

necessary. See component location drawing, Group
9026, for correct connecting of lines.

After installing left transmission, reconnect equip-

ment sump suction line and fill sump.

Install operating pressure valve and fitting in left

transmission pump end cap.

Install bottom access cover.

Install battery tray support, battery tray and seat

latch.
El
1-Eyebolt 3-Right Transmission
2-Left Transmission 4-Hoist Chain Install batteries.

Fig. 2-Left TransmissionRemoval

Fill hydrostatic sump with clean fluid of the recom-
mended type (See Section I, Group V). I
REPAIR
For transmission repair refer to transmission pump Connect fuel lines to bulkhead fittings.
and transmission motor repair sections, this group.
Install rear support plate.
NOTE: Be sure all fittings and openings are
cappep. After transmission has been removed from NOTE: To enable checking transmission and lines
unit, thoroughly clean the outside of the transmission. for leaks, a slave fuel tank may be connected prior to
Either steam clean or wash with diesel fuel. Blow dry installation of era wler fuel tank. The start-up procedure
with compressed air. still must be followed.

Fill transmission with oil. Refer to start-up proce- Set fuel tank in position and reconnect fuel line and
dure, this group. fuel return line.

Coat transmission flange and final drive housing Secure fuel tank in position with cap screws.
flange with Loctite plastic gasket.
IMPORTANT: Do not start engine at this time.
INSTALLATION Refer to start-up procedure, this group.
Position transmission and start six cap screws.
Remove two cap screws from canopy pivot area and
pivot canopy or cab back into position. Install cap
Align transmission motor shaft with final drive shaft
screws at pivot area and rear of canopy.
using special tool JD326. See Group 0399.

Install muffler exhaust tube and tighten clamp.

Tighten six cap screws 170 to 185 lb-fi (230 to 251
Nm) (24 to 26 kg-m) torque.
install access cover below fuel tank.

Follow start-up procedure to start crawler.

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-4 Transmission Hydraulics TM- 1136 (Apr- 79)

Start-Up Procedure Connect engine injection pump shut off solenoid

wire, place shift lever in neutral and lock down emer-
NOTE: This procedure must be completed any time
gency brake pedal.
repairs necessitate draining the oil from the transmis-
sion reservoir, the charge pump oil lines or the trans-
Start engine at slow idle and run at slow idle for 5
mission pump or motor cases.
minutes. This will allow the transmission system to fill
properly.
If the transmissions have been removed from the
tractor, prior to installation fill both the pump and motor
NOTE: The transmission pressure gauge on the
cases with clean fluid of the , recommended type
dash should read in the green zone after start up.
through the pump case drain line port. Cap off case
Pressure gauge fluctuations in the green zone during
drain line fittings and install transmissions.
this period are normal while the transmission system is
filling properly.
After the transmission installation has been com-
pleted and all hydraulic line connections are made,
If the transmission pressure gauge does not read in

q,
complete the following procedure.
the green zone, shut down and troubleshoot. See low
charge pressure symptom, Group 9026. Check for
Remove the two transmission filters from the filter
transmission system fluid leaks and correct as neces-
base and fill both charge pump suction lines w,ith clean
sary.
hydrostatic fluid. The suction lines are the center ports
of each side of filter base.
Shut down engine and recheck reservoir fluid level.
Add fluid as necessary to bring level to center of sight
Pifl the reservoir to the center of the sight glass with
glass.
clean hydrostatic fluid of the type recommended. See
Section I, Group V.
Disconnect the neutral return mechanism cable from
Remove the engine injection pump shut off solenoid
the trip lever in the L.H. console. Place shift lever in the
wire and turn engine over with the starter until the
neutral position and lock down the emergency brake
transmission charge pressure gauge on the dash
pedal. Start engine and run at W.O.T. Move shift lever
reads 30 psi (2 bar) (2 kg/cm2) or more and remains at
slightly into forward. Maintain this direction for 30 sec-
30 psi (2 bar) (2 kg/cm’) or above for 5 seconds.
onds, then move shift lever into reverse. Continue this
/ procedure and gradually increase the distance the
NOTE: Do not operate starter for over 20 seconds
lever is moved until maximum forward and reverse are
at one time and wait at least 2 minutes between
reached. Shut down engine.
cranking attempts.
Bleed transmission control circuit per procedure 13,
Recheck fluid level in reservoir and add fluid as
adjustment section, Group 9026.
necessary to bring level to center of sight glass. Leave
reservoir fill plug loose. This will allow expelling air to
Check engine speed and transmission control valve
escape during starting.
synchronization per procedure 4, adjustment section,
Group 9026.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-75) Transmission Hydraulics 0360-5

TRANSMISSION PUMP Cleanliness

When removing the pump from the transmission,
GENERAL INFORMATION
thoroughly clean the outside of the transmission. Either
steam clean or wash with diesel fuel.

When internal service work is to be performed,

thoroughly clean the work bench, tools, and equip-
ment.

IMPORTANT: Use only diesel fuel to clean parts

on the transmission. Solvents are damaging to the
internal components of the transmission.

Replacement Parts
When servicing the pump, always install new O-
rings, backup washers, and gaskets.

REMOVAL
To service the transmission pump the transmission
must be removed. See hydrostatic transmission, this
group.

Remove displacement control valve lines (5, Fig. 3)

and immediately plug ends of lines and valve openings
to keep clean.

Attach a strap (Fig. 4) around transmission pump

l-Bypass Valve !%Control Valve Lines
and hook to overhead hoist. Remove four cap screws
P-Charge Pump 6-End Cap (7, Fig. 3) and flat washers which attach pump end cap
3-Eyebolt 7-Cap Screw to motor end cap.
4-Displacement Control Valve
NOTE: Eyebolt (3, Fig. 3) is used for transmission
Fig. 3-L.H. Transmission Pump
(Transmission Removed)
removal, not pump removal. Place strap around pump
housing to balance pump for removal.
The transmission pump consists of the transmission
Attach pump to bench stand (1, Fig. 7) using four
pump housing, the bypass valve (1, Fig. 3), the charge
cap screws (3). The bench stand is special tool JD 328.
pump (2), the displacement control valve (4), and the
end cap (6). See Group 0399.

Place oil pan under pump to catch excess oil during

The transmission pump is a reversible variable dis-
placement axial piston pump. There are a L.H. trans- disassembly.
mission pump and a R.H. transmission pump.

Litho in U.S.A.
3 Transmission JD 750 Crawler Bulldozer
0360-6 Transmission Hydraulics TM-1 136 (Nov-75)

IMPORTANT: Protect all highly finished

(lapped) surfaces with clean paper towels to avoid
nicks and scratches. Also, be certain two lapped
surfaces do not slide against each other. Wrap
these parts in paper towels and set to one side so
they will not be bumped during servicing.

NOTE: It is not necessary to remove drive yoke and

input shaft sea/ to service rotating group. Lock yoke
and shaft in position using two 3/8” x 4” cap screws
and nuts (Fig. 5). This will insure that the seal members
do not separate.

If only the rotating group is to be serviced, lock the

drive yoke and input shaft in place and go to charge
pump and end cap removal.

Loosen yoke nut using a yoke holding tool. Do not

remove yoke nut.

Fig. 4-6.H. Transmission Pump Removal

(Transmission Removed)

Fig. d-Yoke Nut Loosening

Pull yoke using an H-bar puller (2, Fig. 7). Remove

yoke nut and yoke.

Fig. 5-Drive Yoke And Shaft Lock

Lifho in U%A.
JD750 Crawler Bulldozer Transmission 3
Tkl- 1136 (Nov- 75) Transmission Hydraulics 0360-7

DISASSEMBLY Remove shaft seal retaining ring with snap ring

pliers (Fig. 8).

l--Transmission Pump 2-H-Bar Puller

Bench Stand 3-Gap Screw

Fig. 7-Drive Yoke Removal

Fig. B-Seal Retainer Removal

Remove seal retainer (Fig. 9) using two screwdriv-

ers. Be careful not to damage lapped surfaces. Be
careful not to lose the six small springs (5, Fig. 11)
which are between the stationary seal (2) and retainer
(3).

IMPORTANT: After seal retainer has been re-

moved, do not use metal tools within this trans-
mission. Use wooden dowels to assist in removing
parts.

Fig. b-Snap Ring Removal

Fig. IO- Rotating Sea/ Removal

Litho in U.S.A.
- -.-.
3 Transmission JD750 Crawler Bulldozer
0360-8 Transmission Hydraulics TM-l 136 (Nov-75)

Use fingers or notched wooden dowels to remove Remove two check valves (2, Fig. 12) in end cap (4)
rotating seal. of pump. Check serviceability of check valves by
cleaning with diesel fuel, checking for free check ball
NOTE: tfyou cannot remove rotating seal with your movement, and then placing diesel fuel on the slotted
fingers, notch two wooden dowels to use for removing end of check valve. If the diesel fuel remains on
seal (Fig. 10). surface of check valve, check valve is good and can be
reused. If diesel fuel seeps into the check valve, the
IMPORTANT: Do not mark or damage the check valve is bad and must be replaced.
lapped surfaces of rotating seal (1, Fig. 11) and
stationary seal (2). NOTE: If one check valve is to be replaced, be
certain to replace both check valves. This will provide
uniform operation of check valves.

l-Rotating Seal Lapped Surface 6-Spring (6 used)

2-Stationary Seal Lapped Surface 6-O-Ring (2 used)
3-Seal Retainer 7--O-Ring
l-Charge Pump 4-End Cap
4-Snap Ring +-Drive Shaft Coupling
2-Cheek Valve (2 used)
3-Gap Screws (4 used) Gldler Shaft Plug
Fig. 1 l-Shaft Seal Kit
7-Drive Shaft

Wrap rotating seal and stationary seal in clean paper Fig. 12-Charge Pump and Check Valve Removal
towels to protect lapped surfaces.
NOTE: When removing end cap, insure that valve
Rotate pump bench stand to remove charge pump p/ate does not fall away from end cap.
(1, Fig. 12). Loosen four cap screws (3) and remove
pump gasket from end cap (4). Do not remove the two The end caps for left and right transmission pump
cap screws that hold the pump together. are different.

IMPORTANT: Do not loosen idler shaft plug (6) The left pump end cap is one piece and can be
and do not remove drive shaft (7) from charge removed by removing eight cap screws.
pump.
The right pump end cap is a two-piece end cap. The
NOTE: If charge pump requires servicing, see two sections do not need to be separated unless the
charge pump section, this group. seals are bad.

Remove the drive shaft drive coupling (5, Fig. 12) Remove the end cap by removing the seven visible
located in the drive shaft bore of the end cap. cap screws and the cap screw which is under the
O-ring plug (Fig. 13) behind the charge pump. The
charge pump must be removed.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov- 75) Transmission Hydraulics 0360-9

After eight cap screws have been removed, it may If it is necessary to pry valve plate loose from end
be necessary to tap the end cap to break the gasket cap, use wooden dowel and pry only at dowel pin
seal. groove (Fig. 15).

Fig. 75-Valve Plate Removal

If valve plate does not come off with end cap,

remove valve plate from bearing plate. It may be
necessary to apply diesel fuel between valve plate and
bearing plate to cut oil film.
Fig. 13-Remove Cap Screw Behind This Plug NOTE: Protect surfaces of valve p/ate and bearing
plate by wrapping them in clean paper towels and
Check end cap gasket to see if more than one placing ouf of the way.
gasket has been used. If more than one has been Remove bearing plate using your fingers (Fig. 16) or
used, it will be necessary to install the same number wooden dowel.
during assembly if drive shaft, end cap, front cover, or
bearings are not replaced.

NOTE: Be careful not to nick or scratch lapped or

machined surfaces of end cap (1, Fig. 14), valve plate
(2) or bearing plate (3).

l-End Cap Machined Surface 3-Bearing Plate

P-Valve Plate Lapped ‘Surface Lapped Surface

Fig. 74-Pump Lapped Surfaces

Fig, 16-Bearing Plate Removal

Litho in U.S.A.
 3 Transmission JD750 Crawler Bulldozer
0360-l 0 Transmission Hydraulics TM-1 136 (Nov-75) (

Fig. 17-Pilot Ring Removal

Remove pilot ring (Fig. 17).

L
Remove rear bearing from end of shaft using a
JD323 puller (Fig. 18). See Group 0399.
T45078N
NOTE: To insure that the lapped surface of the
cylinder block assembly is not scratched or nicked l--4-3/4” (120.7 mm) 3-l-1/4” (31.8 mm) Radius
while the rear bearing is being pulled, a cardboard 2-l” (25.4 mm) 4-l-1/2” (38.1 mm)

template (Fig. 19) should be made to be placed be-

Fig. 19-Cardboard Template
tween cylinder block and bearing puller.
Remove shaft spacer (Fig. 20).

Fig. IS-Rear Bearing Removal

Fig. 20-Shaft Spacer Removal

Remove cylinder block assembly (Fig. 21).

NOTE: Do not nick or scratch lapped surface of

cylinder block.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-l 136 (Nov-78) Transmission Hydraulics 0360-11

l-Cylinder Block 4-Piston Retainer

fig. Pl-Cylinder Block Assembly Removal 2-Spring (6 used) 6-Piston (9 used)
3-Ball Guide 6-Piston Slipper

If pistons (5, Fig. 23) do not come out with cylinder Fig. 23-Cylinder Block Assembly
block (l), remove as follows:
NOTE: Protect face surface of piston slippers (6).
Remove ball guide (3). Wrap piston assembly in clean paper towels and set to
one side.
Remove piston assembly (nine pistons) (5, Fig. 23)
with retainer (4). It is necessary to reach into housing If it is necessary to replace spring (3, Fig. 25) at rear
with both hands to remove all pistons and retainer. of cylinder block (5), use a press (Fig. 24) to facilitate
removal of the spiral lock ring (1, Fig. 25). Replace
spring and install remaining parts. Be certain to install
beveled retainer (4) with beveled side toward splined
end of cylinder block. Install outer ring (2) with shoulder
toward open end of cylinder block.

NOTE: Do not nick or scratch lapped surface of

cylinder block.

l-Shaft Missing Tooth P-Stamped “s” on

Short Shaft

Fig. 22-Pump Shaft

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3 Transmission JD 750 Crawler Bulldozer
0360-l 2 Transmission Hydraulics TM-l 136 (Nov-78) ,,

1--Swashplate P-Thrust Plate

Fig. PB-Thrust Plate Removal

Remove eight cap screws and washers from dis-

placement control valve (1, Fig. 27).

Pull control valve away from pump housing and slide

feedback arm pin (2) out of swashplate link (3).

IMPORTANT: Do not place control valve on its

feedback arm. If the feedback arm is bent, the valve
must be replaced.

If displacement control valve requires servicing, see

pump displacement control valve disassembly in this
group.
l-Spiral Lock Ring 4-Beveled Retainer
2-Outer Ring 5--Cylinder Block
3-Spring

Fig. 25-Cylinder Block Parts

Remove thrust plate (2, Fig. 26). It may be neces-

sary to drip diesel fuel between the thrust plate and
swashplate (1) to break the oil film. Do not use metal
tools to pry these plates apart.

NOTE: Do not nick or scratch the lapped surface of

the thrust plate. Wrap the thrust plate in clean paper
towels and set to one side.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Apr- 79) Transmission Hydraulics 0360-13

NOTE: Cylinders must not be interchanged.

Mark each cylinder and pump housing with horizon-

tal and vertical scribe lines (2, Fig. 28).

Remove servo cylinder retainers (4).

Remove servo cylinders by turning and pulling on

cylinder. Count the number of turns required during
removal so the cylinder can be reinstalled to the same
point.

Convenience tool JDG-37 (servo sleeve special

socket set) may be used to aid in removing servo
cylinders.
l-Displacement Control l-Feedback Arm Pin
Valve 3-Swashplate Link
IMPORTANT: Exact number of turns must be
Fig. 27-Control Valve Removal noted and used on reassembly or pump will not
have neutral.
Before removing the servo cylinders, mark and
scribe the pump housing, servo cylinders, and re-
tainers (Fig. 28).

Fig. 29-Servo Cylinder Removal

l-Servo Cylinder, Pump 2-Scribe Lines

Housing and Retainer 3--Servo Cylinders
Marks 4-Retainers

Fig. 28-Marking and Scribing Servo Cylinders

Number each servo cylinder (3) and pump housing

to facilitate reassembly.

Litho in U.S.A.
 3 Transmission JD750 Crawler Bulldozer
0360-I 4 Transmission Hydraulics TM- 1136 (Apr- 79)
.---

sb 3
4

l'4509ON

l-Nut (2 used) 3-Swashplate Stop

2-Front Cover (2 used)
4-Depth Micrometer

Fig. 31-Swashplate Stop Replacement

l-Servo Piston Assembly 2-Servo Cylinder (2 used)

(2 used) 3-Retainer (2 used)

Fig. 30-Servo Cylinders Removed

Remove pump housing from bench stand and place

on clean work bench.

Remove the front cover (1, Fig. 32) and gasket.

IMPORTANT: Do not remove or alter swashplate

stops (4) from front cover. These stops are factory
adjusted and are not service items. If stops are
altered the crawler will mistrack.

NOTE: If front cover is replaced, measure the dis-

l-Front Cover 3-Swashplate
tance from the front cover to the edge of the stops (Fig.
2-Shaft 4-Swashplate Stop
31). Remove the stops from the old cover and install (2 used)
them in the new cover at the precise depth. 5-Shaft Sealing Surface

Fig. 32-Front Cover and Shaft Removal

Remove the shaft (2, Fig. 32) from the center hole of
the swashplate (3).
Inspect front bearing and if it needs to be replaced,
press it off.

NOTE: If bearing is replaced, inspect the shaft to

see if it is marked ‘S. ” (2, Fig. 22) If it is, a 0.070 inch
(0.25 mm) shim must be placed between the shaft and
the front bearing prior to replacing the bearing.

litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Transmission Hydraulics 0360-15

NOTE: In most cases it will not be necessary to

disassemble the pump any further. However, the re-
maining disassembly procedure should be used if it is
necessary to disassemble the servo pistons or swash-
plate.

NOTE: Support swashptate before removing trun-

nions. Failure to do so could cock trunnion bearings.

Scribe a line on both trunnions (1, Fig. 33) and pump

housing and mark trunnions and housing to facilitate
correct assembly of trunnions after servicing the pump.
Trunnions cannot be interchanged.

Remove trunnions by placing a cap screw or pull

hammer in the threaded center hole of the trunnion and
pulling (Fig. 34).

NOTE: Do not pry the trunnion.

Fig. 34-Trunnion Removal

The trunnion bearings (6, Fig. 35) are “slip fit.” If

they are to be removed, do not use a puller or a pry bar.
Keep shims (2) with each trunnion.

1-Trunnion 2-Swashplate

Fig. 33-Scribing Trunnions and Pump l-lousing

l--Scribe Line 4-Trunnions

2-Shims !&O-Ring
3-Swashplate 6-Bearing

Fig. 35-Trunnions Removed

Remove swashplate and servo piston assembly

from pump housing.

The servo piston assemblies (4, Fig. 36) may be

removed from the swashplate (5) by removing the pins
(7). These pins are press fit so you will need to drive
them out carefully.

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-16 Transmission Hydraulics TM- 1136 (Nov-78)

NOTE: If servo piston assemblies are removed

from the swashplate, keep each piston with its re-
spective cylinder.

If servo piston (1, Fig. 37) must be disassembled,

use a long l/4-inch socket to reach cap screw (5)
inside spring guide (3). Removing cap screw will permit
disassembly of piston.

l-Control Link 5-Swashplate

2-Pin 6-Snap Ring (2 used)
%-Snap Ring 7-Pin l-Piston 4-Washer
4-Servo Piston 2-Spring 5-Cap Screw
3-Spring Guide
Fig. 36-Swashplafe and Servo Piston Assembly
Fig. 37-Servo Piston Disassembled

Cap screw (5) must be replaced if removed.

bitho in U.S.A.
 JD750 Crawler Bulldozer Transmission 3
TM-1 136 (Apr-79) Transmission Hydraulics 0360-17

.‘\

lV1697N

l-Cap Screw (6 used) 16O-Ring (2 used) 31-Cylinder Block 46End Cap

2-Trunnion (2 used) 17-Rotating Seal 32-Pin 47-Coupling
:..:
3-Shim (use as required) l&Stationary Seal 33-Beveled Retainer 48-Cheek Valve (2 used)
4-O-Ring (2 used) W-O-Ring 34-Spring 49-Gap Screw (8 used) :.
6-Trunnion Bearing (2 used) 29-Spring (6 used) 36--Spacer IO-Servo Retainer (2 used)
6-Pump Housing Sl-Seal Retainer 36-Outer Retainer 61-Servo Cylinder (2 used)
7-Thrust Plate 22-Snap Ring 37-Spiral Lock Ring 52-O-Ring (2 used)
&Control Link 23-Shaft Seal Kit 38-Bearing Plate Pilot Z&-O-Ring (2 used)
9-Pin 24--Screen Filter (2 used) 39-Bearing Plate M-Cap Screw (2 used)
16-Swashplate 26-Plug 46-Valve Plate 56-Spring Guide (2 used)
1 l-Gasket 26-Drive Shah 41-Rear Bearing 66-Spring (2 used)
12-Front Bearing Sir-Piston Assembly (9 used) 42-Shim 67-Servo Piston (2 used)
13-Pin 28-Piston Retainer 43-Pin 68-Pin (2 used)
14-Front Cover 29-Ball Guide 44-Gasket 59-!9him (use only wtth
16-Gap Screw (12 used) 39-Spring (6 used) 46-Pin short shaft)
B&-Screen Filter
Fig. 38-Exploded View of Variable Displacement Pump (L.H. Transmission)

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-l 6 Transmission Hvdraulics TM-1 136 (Apr-79)

INSPECTION Bearing races in swashplate should be inspected for

wear or brinnelling. If brinnelling causes jerky swash-
Wash all parts in diesel fuel and dry thoroughly. Coat
plate movement, the bearing should be replaced.
all parts with clean hydrostatic fluid.

Excessive wear on the valve plate, bearing plate and

IMPORTANT: Be very careful when handling
ball guide should be checked closely.
these parts during washing, drying, and inspec-
tion.
Inspect splines for wear and galling.

NOTE: To dry parts after washing in diesel fuel,

Be certain all bearings rotate freely.
shake off excess liquid and blow dry with clean com-
pressed air. DO NOT drip dry with rags or paper
IMPORTANT: Use only JD bearings ordered by
towels.
specific part number as they are selected for close
tolerances and bearing manufacturer’s numbers
inspect all surfaces for excessive wear, nicks,
may be the same but not matched to the necessary
scratches or scoring.
close tolerances.

Inspect second land from the outside of the piston

NOTE: If the pump is found to have contaminants in
slippers for nicks or scratches.
it, disassemble the motor and inspect it.

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JD750 Crawler Bulldozer Transmission 3
TM-l 136 (Nov-78) Transmission Hydraulics 0360-19

ASSEMBLY Cover servo pistons (4, Fig. 36) and swashplate (5)
with hydrostatic fluid. Assemble servo pistons to
NOTE: Be certain to install new O-rings and gas-
swashplate by pressing pins (7) into swashplate links
kets when assembling pump.
and secure snap rings (6) to pins. Be careful not to nick
piston or swashplate surfaces.
Have a small can of hydrostatic fluid and a container
of petroleum jelly available. Apply a light coat of hy-
NOTE: Be certain links on piston assemblies are
drostatic fluid to each surface prior to assembly. Apply
set with bend toward center of swashplate (1, Fig. 39).
a light coat of petroleum jelly to all O-rings prior to
assembly.
Assembie control link (1, Fig. 36) to swashplate.

Refer to Figure 38 (exploded view) and if any of the

Install swashplate in pump housing. Tip swashplate
parts listed below have been replaced, it will be nec-
and lay control link along the top of the swashplate so it
essary to check drive shaft end play before completely
can be reached through the control valve opening.
assembling the pump.

These parts are:

6-Pump Housing 26-Drive Shaft
12-Front Bearing 41-Rear Bearing
14-Front Cover 46-End Cap

To check end play, assemble the above parts and

gaskets (11 and 44), being certain bearing cones are
down to shaft shoulders and bearing cups are properly
seated. Tighten end cap and front cover bolts, then
check drive shaft end play.

NOTE: If the front bearing has been removed, in-

spect shaft to see if it is marked “S, ” (2, Fig. 22). If it is,
a 0.010 inch (0.25 mm) shim must be placed between
the shaft shoulder and bearing before the bearing is
pressed on the shaft.

End play of the pump drive shaft (26) must be 0.006

to 0.016 inches (0.15 to 0.41 mm). If the end play is
less than 0.006 inches (0.15 mm), use two end cap
gaskets (44) on the end cap (46). l-Servo Piston Link Bend

fig. 39-Swashplafe/nsfa/lafion
If the end play of the drive shaft exceeds 0.016
inches (0.41 mm), use one shim (42) under the cup of
Apply light coat of hydrostatic fluid to trunnion bear-
the rear bearing (41) in the end cap (46). Each shim is
ings and trunnions. Install trunnion assemblies with
0.010 inches (0.25 mm) thick.
new O-rings in pump housing. The swashplate should
have 0.002 to 0.004 inches (0.05 to 0.10 mm) preload,
Once the correct end play has been established,
3 to 5 lb. (13 to 22 N) (1 to 2 kg) pull on swashplate
disassemble these pieces and proceed with the com-
control link when checking with pull gauge.
plete assembly of the pump as follows:
NOTE: Be certain to ifistall correct trunnion in cor-
NOTE: End play can be checked with the swash-
rect side of housing.
p/ate and servo cylinders installed.

Litho in U.S.A.
 3 Transmission JD750 Crawler Bulldozer
0360-20 Transmission Hydraulics TM-1 136 (Nov-78)

NOTE: If new trunnion bearings or swashplate have NOTE: If a new swashplate, new servo cylinder, or
been installed, it will be necessary to adjust shim new servo piston is installed, it will be necessary to use
packs. There should be not more than 0.008 inches a depth micrometer to obtain the neutral position of the
(0.20 mm) difference in shim packs between sides. swashplate.

Tighten trunnion cap screws. The thrust plate must be installed on the swashplate
for this measurement. I
Apply a light coat of hydrostatic fluid to the inside of
the servo cylinders (1, Fig. 40) and put two new O- Locate the micrometer (1, Fig. 41) on both sides of
rings (2) on each cylinder. the thrust plate (2) (by each servo cylinder) in a line
parallel with the shaft. Adjust servo cylinders in as
Screw cylinders into pump housing counting the evenly as possible so all end play is eliminated. Tight-
number of turns. Insure that the correct servo cylinder en servo cylinders until they touch spring guide. Ex-
goes into the correct bore. cessive tightening will cause spring to bottom and
servos will be inoperative. Then adjust for neutral by
IMPORTANT: insure that the cylinder is tightening one cylinder a small amount (l/8 to l/4 turn)
r- and loosening the other cylinder a like amount until

q
screwed in the same number of turns as when it
was removed. The pump will not have neutral if this both micrometer readings are within 0.001 inch (0.025
is not accurate. mm) of each other, and there is no play in the swash-
plate.
Align scribe lines (4) on cylinder and pump housing
precisely. Correct alignment of scribe lines is neces-
sary to place the swashplate in neutral.

I-Servo Cylinders 3-Cylinder and Pump Markings l-Depth Micrometer P-Thrust Plate
2-O-Rings 4-Scribe Lines
Fig. 47-Setting .%&-p/ate Neutral
I
Fig. 40-Servo Cylinder installation
Install servo cylinder retainers (3, Fig. 42) with
socket head screws. If the slot location has changed
due to replacement of servo cylinders, servo pistons or
swashplate, punch retainer into servo cylinder slot (2)
to prevent cylinder rotation.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov- 75) Transmission Hydraulics 0360-21

If front bearing has been removed, press a new

bearing on the shaft.

IMPORTANT: insure that the bearing does not

damage the sealing surface of the shaft (5, Fig. 32).

IMPORTANT: Use only JD bearings ordered by

specific part number as they are selected for close
tolerances and bearing manufacturer’s numbers
may be the same but not matched to the necessary
close tolerances.

NOTE: Prior to pressing new bearing onto shaft,

inspect shaft to see if it is marked “S, ” (2, Fig. 22). If it
is, a 0.010 inch (0.25 mm) shim must be placed be-
1 -Servo Cylinder 3-Cylinder Retainer tween the shaft shoulder and the front bearing prior to
2-Slot pressing the bearing on the shaft.
Fig. 42-Servo Cylinder Retainer Installation
Remove the thrust plate.

Install new gasket on displacement control valve (1,

Insert the shaft and bearing assembly through the
Fig. 43). Slide valve feedback arm pin (2) into swash-
cast hole in the swashplate.
plate control link (3).
Install the front cover and new gasket, being certain
that the locating pins are in place in the housing. These
pins will align the housing and front cover screw holes.

NOTE: If the front cover is rep/aced, measure the

distance from the front cover to the edge of the stops
(Fig. 44). Remove the stops from the old cover and
install them in the new cover, insuring that they are at
the same depth.

l-Displacement Control 2-Feedback Arm Pin

Valve 3-Control Link

Fig. 43-Displacement Control Valve Installation

Install eight cap screws and washers in valve and

tighten to lo-11 lb-ft (14-15 Nm) (1-2 kg/m) torque.

NOTE: One cap screw has a tighter fit, since it is

used to align the valve to the pump housing.
?450901?

l-Nut (2 used) 3-Swashplate Stop (2 used)

2-Front Cover 4-Depth Micrometer

Fig. 44-.&a&p/ate Stop Replacement

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-22 Transmission Hydraulics TM-l 136 (Nov-75)

Tighten twelve cap screws. Lubricate the thrust plate, pistons, piston slippers
and bores with hydrostatic fluid. Hold the shaft on the
Mount pump housing on bench stand. external end, align the missing tooth of the shaft and
ball guide. Slide the cylinder block assembly onto the
Lubricate the thrust plate with hydrostatic fluid and shaft and against the thrust plate. When properly in-
install in swashplate. The chamfered side of the thrust stalled a spring load can be felt when pushing against
plate fits into the swashplate, and the milled slot fits the cylinder block.
over swashplate dowel pin.
Install the spring guide into the center bore of the
NOTE: Do not nick or scratch the lapped surface on cylinder block.
the thrust plate.
Lubricate rear bearing with hydrostatic fluid.
The cylinder block assembly should be installed
next. There is no special relationship of pistons, bores, Using a bearing press (1, Fig. 46) press the rear
or springs; however, the alignment of the ball guide bearing onto the shaft with the center screw of the
and cylinder block splines is critical. The undersized press. Special tool JD 317 (2) must be used between
tooth in the spline of the cylinder block (1, Fig. 45) must the center screw and the bearing. Do not damage
line up with the missing tooth in the ball guide spline. spline on end of shaft.

These in turn line up with a missing tooth on the NOTE: Use adapters (3) on puller legs to fit into cap
shaft spline (2). screw holes in end cap.

l-Cylinder Block Undersized Tooth l-Bearing Press 3-Adapters

2-Shaft Missing Tooth 2-Special Tool JD 317 4-Rear Bearing

Fig. 45-Cylinder Block Assembly Installation Fig. 46-Pressing Rear Bearing on Shaft

NOTE: The rear bearing must be pressed on until it

rests firm/y on the shoulder of the shaft to insure
adequate bearing clearance.

Litho in U.S.A.
JO750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-75) Transmission Hydraulics 0360-23

IMPORTANT: Use only JD bearings ordered by

specific part number as they are selected for close
tolerances and bearing manufacturer’s numbers
may be the same but not matched to the necessary
close tolerances.

Install the bearing plate pilot ring (1, Fig. 47) in the
center bore of the cylinder block.

Coat cylinder block side of bearing plate (3) with

hydrostatic fluid and install the bearing plate so that the
milled slot (4) locates over the pin (2) in the cylinder
block. After installation, lubricate the exposed surfaces
with clean hydrostatic fluid.

l-End Cap 3-End Cap Pin and

a-Valve Plate Valve Plate Slot

Fig. 48-Valve Plafe to End Cap lnstallafion

Place a new end cap gasket (1, Fig. 49) on the

housing, being certain the locating pins (2) are in place.

NOTE: If more than one gasket was removed dur-

ing disassembly, and the drive shaft, end cap, front
cover, or bearings were not replaced, it will be neces-
sary to rep/ace the same number of gaskets as pre-
viously used.

install new O-ring (3) in the counterbore in the

housing.

l-Bearing Plate Pilot Ring 3-Bearing Plate

2-Cylinder Block Pin 4-Milled Slot

Fig. 47-Bearing P/ate Installation

Lubricate end cap face with hydrostatic fluid. Install

the valve plate (2, Fig. 48) on the end cap (1) so the
slot (3) locates over the pin in the end cap.

l-End Cap Gasket 3-O-Ring

P-Locating Pins (2 used)

Fig. 49-End Cap Gasket and O-Ring installation

Litho in U.S.A.
 3 Transmission JD750 Crawler Bulldozer
0360-24 Transmission Hvdraulics TM- 1136 (Nov- 75)

IMPORTANT: Use extreme care when assem- Install six springs in seal retainer (4, Fig. 50). Install
bling cylinder block, valve plate, bearing plate, and new O-ring between stationary seal and seal retainer
end cap to avoid dropping, nicking or scratching and locate stationary seal (3) in seal retainer by align-
lapped surfaces. ing notch in seal with pin (5) in retainer. Coat O-ring (6)
with petroleum jelly and install on seal retainer.
If any of these parts are damaged, they will have to
be replaced with new parts. Coat O-ring chamfer in front cover bore with petro-
leum jelly and install shaft seal assembly using Special
Install end cap with valve plate to pump housing. Tool Number JD 321 (Fig. 51). Do not damage seal
assembly during installation.
IMPORTANT: Do not let valve plate fall away
from end cap during assembly. IMPORTANT: Care must be taken to insure that
spring load does not disengage stationary seal
,’ Tighten opposite cap screws to be certain end cap from seal pin during installation.
seats properly. Tighten cap screws to 35 to 38 lb-ft (47
to 52 Nm) (4.8 to 5.3 kg/m) torque.

q Install check valves with new O-rings in end cap and

tighten to 30 to 40 lb-ft (41 to 54 Nm) (4 to 6 kg/m)
torque.

NOTE: Use caufion when installing these valves to

prevent damage to the O-ring on the cartridge as if is
inserted past the fhreads.

When installing the charge pump and new gasket on

the end cap, align the gasket so the small relief valve
p&t is open and not blocked by the gasket (Fig. 53).

Place couplin$pn charge pump drive shaft and

install charge pump onto the end cap.

Install four cap screws and tighten to 10 to 11 lb-ft

(14 to 15 Nm) (1.4 to 1.5 kg/m) torque.

Rotate bench stand so front seal assembly can be

installed.

Install new O-ring on rotating seal.

l-Rotating Seal 4-Seal Retainer
2-Special Tool JD 321 %-Retainer Pin
Install rotating seal (1, Fig. 50) using Special Tool
3-Stationary Seal 6O-Ring
Number JD 321 (2). Coat end of special tool with
petroleum jelly and stick rotating seal to tool. Fig. %I-Roiating Sea/ Installation
and Shaft Seal
IMPORTANT: This part is easily damaged and
care must be exercised when installing. Do not
allow seal to drag across shaft when installing, and
do not damage the seal lapped surface.

Seat seal firmly on drive shaft.

Lifho in U.S.A.
JD750 Crawler Bulldozer Transmission 03
TM-1 136 (NOW75) Transmission Hydraulics 0360-25

INSTALLATION
Attach overhead hoist strap to pump.

Insert new O-rings and backup washers in end cap

mounting surface.

Remove cap screws holding pump to bench stand.

Align pump end cap and motor end cap and carefully
insert two cap screws in opposite corners of end caps.

IMPORTANT: When the pump is set on motor, it

must not be moved. Movement could damage
Fig. 57-S/d Sea/ /rsfa/lafion
sealing surface or sealing rings.

install snap ring using snap ring pliers. Snap ring

Lower pump onto motor and tighten cap screws to
must be installed with chamfered side away from as-
170 to 185 lb-ft (230 to 251 Nm) (24 to 26 kg/m).
sembly.
Use special tool JD-332 to torque these cap screws.
If the unit has been properly assembled, the pump
shaft should rotate with 7 to 11 lb-ft (9 to 15 Nm) (1 to
2 kg/m) torque, after breakaway.

Torque readings outside these specifications war-

rant investigation for correct assembly.

Install yoke on tapered shaft and tighten nut to 300

lb-ft (407 Nm) (41 kg/m) torque.

Litho in U.S.A.
 Transmission JO 750 Crawler Bulldozer
_’ 3
0360-26 Transmission Hydraulics TM- 1136 (Nov-75)

CHARGEPUMP
GENERAL INFORMATION
The left charge pump is different from the right
charge pump in that it contains the transmission control
valve charge pump. The serviceability of the two
pumps is identical, but they are not interchangeable.

REMOVAL
The charge pumps may be removed from the trans-
missions without removing the transmission from the
crawler.

Drain the hydrostatic sump.

Before removing the charge pump, be certain to

clean the outside of the charge pump thoroughly. Ei-
ther steam clean or wash with diesel fuel. Also clean
surrounding area so dirt will not get into system when
hoses are disconnected.
l-Idler Shaft Plug ‘I-Spring
If left charge pump is being removed, disconnect 2-Drive Shaft B-Shim
3-Gap Screws (4 used) g-O-Ring
charge hose and suction hose from charge pump. 1O-Hex. Plug
e-Special Pins (2 used)
S-Gasket 1 l-Charge Pump
If right charge pump is being removed, disconnect S-Poppet
suction hose from charge pump.
Fig. 52-Charge Pump Disassembly

NOTE: Cap end of hoses and plug charge pump

ports to maintain system cleanliness.
DISASSEMBLY
Remove hex. plug (IO, Fig. 52), spring (7) and
Remove four cap screws (3, Fig. 52) holding charge poppet (6). Remove the shims (8) from the counterbore
pump to end cap. Do not remove the two bolts holding of the hex plug.
pump sections together.
NOTE: Do not alter these shims unless new parts
NOTE: These sections must not be separated. are used, in which case the valve must be re-shimmed
to the proper setting.
Remove charge pump (11) and gasket (5).
INSPECTION
NOTE: When removing charge pump, it is neces-
sary to overcome friction of special pins (4) in end cap. Clean parts in diesel fuel and dry with compressed
DO NOT pry charge pump to loosen. Tap lightly with a air.
plastic hammer if necessary. When removing pump, be
Inspect parts for excessive wear or scoring. Replace
certain drive shaft and idler shaft plug (1) remain in
parts if necessary.
pump housing.

NOTE: Charge pump cannot be separated for in-

After removing charge pump, cover opening in end
spection or repair. If charge pump is inoperative, re-
cap to keep out dirt.
p/ace entire pump.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-75) Transmission Hydraulics 0360-27

ASSEMBLY Place coupling on charge pump drive shaft and align

with pump drive shaft. Secure four cap screws and
Install poppet, spring, shims and plug for charge
tighten to 10 to 11 lb-ft (14 to 15 Nm) (1 to 2 kg/m)
relief valve. Use new O-ring (9, Fig. 52) on plug.
torque.

NOTE: If new poppet or spring has been installed, it

NOTE: Be certain idler shaft plug does not fall out
will be necessary to re-shim the valve. For proper
when installing charge pump.
setting, see Group 0399.
Connect suction hose and on left charge pump; also
INSTALLATION
connect the control valve pressure hose. Tighten fit-
Install new gasket on charge pump. tings to 17 to 19 lb-ft (23 to 26 Nm) (2 to 3 kg/m) torque
maximum.
NOTE: Be certain slot in gasket (2, Fig. 53) aligns
with slot for charge relief valve (I) in pump housing. Replenish fluid supply with clean hydrostatic fluid.

IMPORTANT: Do not start engine at this time.

Refer to Procedure 1, adjustment section, Group
9026.

l-Charge Relief Valve Slot 2-Gasket Slot

Fig. 53-Charge Pump Assembly

Litho in U.S.A.
 3 Transmission JD750 Crawler Bulldozer
0360-28 Transmission Hydraulics TM- 1736 (Noi-75)

DISPLACEMENT CONTROL VALVE

REMOVAL
The displacement control valve may be removed
from the pump housing without removing the trans-
mission from the crawler.

When removing the displacement control valve, be

certain to thoroughly clean the outside of the trans-
mission. Either steam clean or wash with diesel fuel. If
internal work is to be performed on the control valve,
insure that the work bench, tools, and equipment are
clean.

Mark lines going to control valve and the fittings so

proper lines are connected on reassembly.

ml Remove lines and cap lines and fittings immediately

with clean plugs.

Remove eight cap screws which secure valve as-

sembly to pump housing.

Pull valve away from pump housing and slide feed-

back arm pin out of swashplate control link (Fig. 27).

Remove valve assembly and gasket. l-Spring Pin 3-End Cap

P-Gasket

NOTE: Cover opening in pump housing to keep out Fig. 54-End Cap Removal
dirt while servicing valve.

REPAIR
Remove end cap (3, Fig. 54) and gasket (2) by
removing four cap screws.

Remove spring pin (1) so shuttle valve can be

removed. Discard spring pin.

Thread No. IO-24 screw into shuttle valve plug (2,

Fig. 55) and remove. Plug is held in place by O-ring
pressure.

Remove shuttle valve (3).

Inspect shuttle valve. If it is marked with an “A” on its

housing, be certain to specify the proper replacement
spool when ordering a new valve.

l-Spring Pin 3-Shuttle Valve

2-Shuttle Valve Plug

F;g. 55-Shuttle Valve Removed

Litho in U.S.A.
 JD 750 Crawler Bulldozer Transmission 3
TM- 1136 (Feb- 77) Transmission Hydraulics 0360-29

Remove jam nut (1, Fig. 56), washer (2), and indi-
cator arm (3) from indicator assembly.

The indicator shield (4) does not need to be re-

moved to remove the indicator sleeve (6). Use channel
lock pliers and remove assembly.

Shield (4) and felt packing (5) can be removed from

sleeve (6).

l-Do Not Alter 4-May Be Removed

~-DO Not Alter -5-May Be Removed
~-DO Not Alter S-Do Not Alter

Fig. 57-Working Areas Within Valve

Drive spring pin (1, Fig. 58) out of h&sing and

remove spool sleeve and assembly plug (2). Use a No.
lo-24 screw to pull plug out of housing.

l-Jam Nut !5-Felt Packing

O-Washer 64ndicator Sleeve
34ndicator Arm 7-O-Ring
4-Shield &O-Ring

Fig. 56-Swashplate Indicator Assembly

The inner portions of the displacement control valve

can be disassembled for cleaning purposes only. Care
must be taken when working in this valve, since dam-
age to the valve and sleeve assembly or to the internal
operating mechanism will cause replacement of the
entire valve.

Refer to Figure 57 for areas within the valve where

l-Spring Pin 2-Sleeve and Spool Plug
disassembly for cleaning can be done.
Fig, 58-Sleeve and Spool Plug Removal

,-- Litho in U.S.A.

-- -- m‘, ..;;’
 3 TGsmission JD750 Crawler Bulldozer
L.... au..
0360-30 Transmission Hydraulics TM- 1136 (Feb- 77)
,

Remove cap screw (1, Fig. 59) washer (2), and

spacer (3) from spool arm (4). Spool arm will rotate up
and there is another washer under arm.

l-Spool Arm 3-Valve Spool

,:
2-Ball

Fig. 60-SpoolArm Ball Disengagement

El

l-Cap Screw 5-W Screw

2-Washer 6-Sleeve and Spool
3-Spacer Plug
4-Spool Arm 7-Spring Pin

.+ Fig. 59-Spool Arm Cap Screw Removal

Remove sleeve set screw (5, Fig. 59) and discard.

Rotate spool arm (1, Fig. 60) and disengage the ball
(2) from the valve spool (3).

The sleeve and spool assembly can now be pushed

out of the housing (Fig. 61). fig. dl-Sleeve and Spool Removal

NOTE: Drive sleeve and spool assembly out of the

housing.

NOTE: Be careful not to nick or scratch the spool

and sleeve surfaces.

Fig. 62-Spool and Sleeve Removed

Litho in U.S.A.
,
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-75) Transmission Hydraulics 0360-31

INSPECTION ASSEMBLY
Clean all parts in diesel fuel and dry with com- NOTE: Be certain to install new O-rings and gas-
pressed air. kets when assembling displacement control valve.

Inspect parts for excessive wear or scoring. Be certain all parts are clean and dry.

If spool and sleeve assembly needs to be replaced, Apply a light coat of hydrostatic fluid to all parts prior
replace the entire valve. to assembly.

Coat all parts with hydrostatic fluid if there is any Assemble spool in sleeve so the spool hole (1, Fig.
time delay prior to assembly. 64) is visible through the sleeve slot (2).

Slide the sleeve and spool assembly into the valve

housing so the sleeve set screw hole (3) aligns with the
r housing set screw hole (4).

_-,’
0
I 24
27-l
8
25
a”?
22
21 28-q -20
29-q
30-N

l-Cap Screw (4 used) g-Valve Housing M-Washer 23-Sleeve and Spool Assembly
2-End Cap 1 O-Plug 17-Shield 24-C-Ring
3-Gasket 1 l-C-Ring l&lam Nut 25-Plug
4-Washer (2 used) 12-C-Ring 19-Washer (8 used) 26Spring Pin
S-Spacer 13-Indicator Sleeve 2tt-Cap Screw (8 used) 27-Shuttle Valve
6-Gap Screw M-Felt Packing 21-C-Ring 28-C-Ring
7-Control Valve Gasket 15-Indicator Arm 22-Plug 2g-Spring Pin
&Set Screw \ 3tI-Spring Pin

Fig. 63-Pump Displacement Control Valve (Exploded View)

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3 Transmission JO750 Crawler Bulldozer
0360-32 Transmission Hvdraulics TM- 1136 (Nov- 75)

INSTALLATION
Install new valve gasket on housing. Slide valve
feedback arm pin (2, Fig. 65) into swashplate control
link (3).

l-Spool Hole 3-Sleeve Set Screw Hole

2-Sleeve Slot 4-Housing Set Screw
Hole

Fig. 64-Sleeve and Spool Installation

Install new set screw and tighten to 25 to 30 lb-in

(2.8 to 3.4 Nm) (0.29 to 0.35 kg/m) torque.
l-Displacement Control 2-Feedback Arm Pin
Install washer under spool arm and rotate arm so Valve 3-Control Link

ball engages in hole in spool. Insert spacer, washer, Fig. 65-Displacement Contra/ Valve lnstaliation
and cap screw. Tighten cap screw to 30 to 36 lb-in (3.4
to 4.1 Nm) (0.35 to 0.41 kg/m) torque.
Install eight cap screws and washers in valve and
tighten to 10 to 11 lb-ft (14 to 15 Nm) (1 to 2 kg/m)
Place new O-ring on sleeve and spool plug, and
torque.
install in housing. Install spring pin.
The pump swashplate is spring centered in neutral,
Inspect the O-ring (8, Fig. 56) on indicator spool and
so the indicator should now be set to the zero position
replace as necessary. Install O-ring (7) on indicator
and the jam nut tightened.
sleeve (6). Install indicator sleeve and tighten.
NOTE: If transmission does not have proper neutral
Install felt packing (5).
after start-up, refer to Procedure 20, adjustment sec-
tion, Group 9026.
Install indicator shield (4).

Install indicator (3), washer (2), and jam nut (1).

NOTE: Do not tighten jam nut until control valve is

installed on pump.

Install shuttle valve.

Place O-ring on shuttle valve plug and install plug in

housing.

Install new spring pin in housing.

Install end cap cover gasket, and cap screws.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov- 75) Transmission Hydraulics 0360-33

l-Valve Covers (2 used) 4-Backup Washer (2 used) 7-Seal Ring

2-Gasket (2 used) 5-O-Ring (2 used) &Spring
3-Valve Housing S-Valve and Piston Assembly g--Spring

Fig. 66-Bypass Valve Disassembled

REMOVAL DISASSEMBLY
The bypass valve may be removed from the trans- When internal work is to be done on the valve,
mission without removing the transmission from the insure that the work bench, tools and equipment are
crawler. clean.

Before removing the bypass valve, be certain to

thoroughly clean the outside of the transmission. Either A CAUTION: Before disassembling bypass
valve, secure valve covers with spring
steam clean or wash with diesel fuel. compressor clamp. The springs in the valve are
high compression and care must be taken during
Drain the hydrostatic sump. removal (Fig. 67).

If left bypass valve is being removed, mark lines and Remove four cap screws and washers from each
disconnect the crossover hoses from the valve and cap valve cover.
the hoses and fittings.

If right bypass valve is being removed, mark lines

and fittings and disconnect the crossover hoses and
the rear bypass drain and pressure tubes. Cap the
hoses, tubes, and fittings with clean caps.

Remove the four cap screws and washers.

NOTE: Do not damage mounting surfaces of end

cap or valve while disassembling.

Litho in U.S.A.
3 Transmission JO750 Crawler Bulldozer
0360-34 Transmission Hydraulics TM-l 136 (Nov-75)

ASSEMBLY
Coat all parts with hydrostatic fluid prior to assembly.

Place seal ring (7, Fig. 66) on piston and install valve
and piston assembly (6) in valve housing (3).

Place new gasket (2) on bottom valve cover (1) and

install four cap screws and washers.

Place springs (8 and 9) on valve spool.

Place new gasket on top valve cover and using

spring compressor clamp, tighten valve cover down to
housing.

install four cap screws and washers. Tighten eight

cap screws to 10 to 11 lb-ft (14 to 15 Nm) (1 to 2 kg/m)
torque.

INSTALLATION
Install new O-rings and backup washers in the
counterbore of the valve housing.

The O-ring goes into the counterbore, followed by

Fig. 67-Spring Compressor on Valve Housing the backup washers.

Loosen spring compressor and remove valve covers The backup washers should be installed with the flat
(1, Fig. 66), gaskets (2), and springs (8 and 9). side of the washer toward the end cap of the pump.

NOTE: Be extrem /y careful of the surface of end

cap and the bypas s/”valve. Any nicks or scratches on
these surfaces/ould cause replacement of the parts.

Place bypass valve on end cap and install four cap

screws and washers.

Connect crossover hoses and rear bypass pressure

and drain tubes, if transmissions are in the crawler.
See component location drawing, Group 9026, for
proper line connections.

Refer to Procedure 1, adjustment Section, Group

9026, for start-up procedure.

Litho in U.S.A.
 JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-75) Transmission Hydraulics 0360-35

TRANSMISSION MOTOR
GENERAL INFORMATION Cleanliness
When working on the transmission motor,
thoroughly clean the transmission prior to removing the
pump from the motor. Either steam clean or wash with
diesel fuel and blow dry.

When internal service work is to be performed,

thoroughly clean the work bench, tools, and equip-
ment.

IMPORTANT: Use only diesel fuel to clean parts

on the transmission. Solvents are &Waging to the
internal components of the transmission.

q
Replacement Parts
When servicing the motor, always install new O-
rings, backup washers, and gaskets.

REMOVAL
To service the transmission motor, the transmission
must be removed. See hydrostatic transmission re-
moval, this group.

Disconnect displacement control valve lines (4, Fig.

68) and plug ends of lines and valve openings with
clean plugs.

Remove the transmission pump and set to one side.

l-Motor Housing 3-Manifold Valve
See transmission pump, this group.
2-Displacement Control 4-Control Valve Lines
Valve Cover end cap pump to motor mounting surfaces
with tape to keep dirt out of end caps and to protect
Fig. 68-L.H. Transmission Motor
surfaces (Fig. 69).
(Transmission removed)

Place oil pan under motor to catch excess oil during

The transmission motor consists of the transmission
disassembly.
motor housing (1, Fig. 68), the displacement control
valve (2), the manifold valve (3), and the end cap.

The transmission motor is a variable displacement

axial piston motor. There are a L.H. transmission motor
and a PH. transmission motor.

-~ Litho in U.S.A.
 _
3 Transmission JD750 Crawler Bulldozer
0360-36 Transmission Hydraulics TM-1 136 (Nov-75)

Fig. 69-L. H. Transmission Motor (With Pump Removed)

IMPORTANT: Protect all highly finished

(lapped) surfaces with clean paper towels to avoid
nicks and scratches. Also, be certain two lapped
surfaces do not slide against each other. Wrap Fig. 77-Drive Shaft Locked in Place
these parts in paper towels and set to one side so
they will not be bumped during servicing. Remove shaft seal snap ring with snap ring pliers
(Fig. 72).
/ NOTE: If is not necessary to remove drive shaft
seal to service rotating group. Lock shaft in place using
an H-bar puller (1, Fig. 70), and a bearing cup pulling
attachment (2) to insure that seal members do not
separate.

l--H-bar Puller 2-Bearing Cup Pulling Attachment Fig. 72-Snap Ring Removal

Fig. 7OOive Shaft Locking Tools

Remove seal retainer (Fig. 73) using two screwdriv-
ers. Be careful not to damage lapped surfaces.
If only the rotating group is to be serviced, lock drive
shaft in place (Fig. 71) and go on to end cap removal.

Lifho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Transmission Hydraulics 0360-37

Fig. 73-Seal Retainer Removal

IMPORTANT: After seal retainer has been re-

moved, do not use metal tools within this trans- l-Rotating Seal Lapped Surface 6-Spring (6 used)
mission. Use wooden dowels to assist in removing 2-Stationary Seal Lapped Surface 6-GRing (2 used)
parts. 3-Seal Retainer 7-O-Ring
4-Snap Ring

Remove stationary seal. Fig. 75-Shaft Seal Kit

Use fingers or notched wooden dowels to remove Wrap rotating seal and stationary seal in clean paper
rotating seal (Fig. 74). towels to protect lapped surfaces.

IMPORTANT: Do not mark or damage the To remove the end cap, place two eyebolts in the
lapped surfaces of the rotating seal (I, Fig. 75) and cap screw holes. Thread a strap through eyebolts and
stationary seal (2). attach to overhead hoist (Fig. 76).

IMPORTANT: When removing end cap, be sure

the valve plate does not fall away from end cap.

Tighten hoist strap and remove eight cap screws. It

may be necessary to tap end cap to break gasket seal.

Place end cap on bench taking care not to let valve

plate fall.

Fig. 74Rotating Seal Removal

Lifho in U.S.A.
3 Transmission JD 750 Crawler Bulldozer
0360-38 Transmission Hvdraulics TM-l 136 (Nov-78)

fig. 77-Valve f/ate Removal

If valve plate does not come off with end cap,

remove it from bearing plate. It may be necessary to
apply diesel fuel between valve plate and bearing plate
to cut oil film.

NOTE: Protect surfaces of valve plate and bearing

plate by wrapping them in clean soft paper towels and
placing them out of the way.

Remove bearing plate using your finger or wooden

Fig. 76-End Cap Removal dowel (Fig. 78). Pry only at dowel pin slot.

Check end cap gasket to see if more than one

gasket has been used. If more than one .has been
used, it will be necessary to install the same number
during assembly, if drive shaft, end cap, front cover or
bearings are not replaced.

NOTE: Be careful not to nick or scratch the lapped

surfaces of the valve plate or the bearing plate.

Remove valve plate from end cap. It may be neces-

sary to pry valve plate loose from end cap. Use only a
wood dowel and pry only at dowel pin groove (Fig. 77).

Fig. 78-Bearing Plate Removal

Litho in U.S.A.
 JD750 Crawler Bulldozer Transmission 3
TM-1 136 (Nov-78) Transmission Hydraulics 0360-39

T45078N

l-6-114 in. (158.8 mm) 3-l -5/8 in. (41.3 mm)

2-l-1/2 in. (38.1 mm) Radius
4-2 in. (50.8 mm)

Fig. 79-Rear Bearing Removal

Fig. BO-Cardboard Template

I Remove bearing plate pilot.

Remove rear bearing from end of shaft using a

JD322 puller (Fig. 79). See Group 0399, this section.

NOTE: To insure that the lapped surface of the

cylinder block assembly is not scratched or nicked
while the rear bearing is being pulled, a cardboard
template (Fig. 80) should be made to be placed be-
tween the cylinder block and bearing puller.

I Remove spring guide.

Remove cylinder block assembly (Fig. 81). Use a

wooden dowel to assist in removal.

NOTE: Do not nick or scratch the lapped surface of

the cylinder block.

If pistons (5, Fig. 82), do not come out with cylinder

block (I), remove as follows: Fig. 8 I-Cylinder Block Assembly Removal

Remove ball guide (3). It is necessary to align NOTE: Protect face surface of piston slippers (6,
missing tooth in guide with missing tooth on shaft to Fig. 82). Wrap piston assembly in clean paper towels
remove ball guide (Fig. 83). and set to one side.

Remove piston assembly (nine pistons) (5, Fig. 82)

with retainer (4). It is necessary to reach into housing
with both hands to remove all pistons and retainer.

Lifho in U.S.A.
-cI Transmission JD 750 Crawler Bulldozer
0360-40 Transmission Hydraulics TM- 1136 (Nov-78)

If it is necessary to replace spring (3, Fig. 85) at rear

of cylinder block (5) use a press (Fig. 84) to facilitate
removal of the spiral lock ring (1, Fig. 85). Replace
spring and install remaining parts. Be certain to install
beveled retainer (4) with beveled side toward splined
end of cylinder block. Install outer ring (2) with shoulder
toward open end of cylinder block.

l-Cylinder Block 4-Piston Retainer

P-Spring (6 used) 6-Piston (9 used)
3-Ball Guide 6-Piston Slipper

Fig. BP-Cylinder Block Assembly

Fig. 84-Spiral Lock Ring Removal

Fig. 83-Shaft Missing Tooth

NOTE: Do not nick or scratch lapped surface of

cylinder block.
l-fietaining Ring 4-Spring Seat
P-Spring Retainer !T--Cylinder Block
3-Spring

Fig. 8BCylinder Block Parts

Litho in U.S.A.
 JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Transmission Hydraulics 0360-41

Remove thrust plate (Fig. 86). It may be necessary

to drip diesel fuel between the thrust plate and swash-
1 plate to break the oil film. Do not use metal tools to pry
these plates apart.

NOTE: Do not nick or scratch the lapped surface of

the thrust plate. Wrap the thrust p/ate in clean paper
towels and set to one side.

1-Eyebolt 3-Motor Housing

2-Hoist Strap 4-Front Cover

Fig. 87-Motor Housing Removal

Remove eight cap screws and washers from dis-

placement control valve (1, Fig. 88).

Pull control valve away from motor housing and slide

valve feedback arm pin (2) out of swashplate control
Fig. b&Thrust Plate Removal
link (3).

insert an eyebolt (1, Fig. 87) in the top trunnion.

Attach a strap (2) through the eyebolt and onto an
overhead hoist. Remove the twelve cap screws and
washers and move the motor housing (3) away from
the front cover (4). As you move the housing, remove
the motor shaft and bearing assembly.

Inspect front bearing and if it needs to be replaced,

press it off.

NOTE: If bearing is replaced, inspect the shaft to

see if if is marked “S. ” (3, Fig. 96) If it is, a 0.070 inch
(0.25 mm) shim must be p/aced between the shaft and
the front bearing prior to replacing the bearing.

NOTE: Do not nick or scratch the rotating seal

l-Control Valve 3-Swashplate Control Link
surface of the shaft (1, Fig. 96). 2-Valve Feedback Arm Pin

Place motor housing on a clean work bench for Fig. 88-Control Valve Removal
further disassembly.

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-42 Transmission Hydraulics TM-1 136 (Nov-78)

IMPORTANT: Do not place control valve on its

feedback arm. If the feedback arm is bent, the valve
must be replaced.

If the displacement control valve requires servicing,

see motor displacement control valve disassembly,
this group.

IMPORTANT: Do not remove or alter the

swashplate stop (Fig. 89) from the front cover. The
stop is factory adjusted. If this stop is altered, the
crawler will mistrack.

NOTE: If the front cover is rep/aced, measure the

distance from the front cover to the top edge of the stop
w
(Fig. 90). Remove the stop from the old cover and T45090N
install it in the new cover, insuring that it is at the
l-Nut 3-Swashplate Stop (2 used)
precise depth as before. 4-Depth Micrometer
2-Front Cover

Fig.-OO-Swashplate Stop Replacement

Fig. &?9-Front Cover Stop

Before removing the servo cylinders, mark and l-Servo Cylinder Motor 3-Scribe Lines
scribe the motor housing, servo cylinders, and re- Housing and Retainer Marks 4-Servo Cylinders

tainers (Fig. 91). 2-Retainers

Fig. 9 l-Marking and Scribing Servo Cylinders

Number each servo cylinder (3) and motor housing
to facilitate reassembly.

NOT.!? Cylinders must not be interchanged.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Aor- 79) Transmission Hydraulics 0360-43

Mark each cylinder and motor housing with hori- NOTE: If new servo cylinder is installed, it will be
zontal and vertical scribe lines (3, Fig. 91). necessary to measure depth of stop and replace if in
new servo cylinder. Measure depth with depth mi-
Remove servo cylinder retainers (4).
crometer and install it in new cylinder precisely (Fig.
Remove servo cylinders by turning and pulling on 93).
cylinder. Count the number of turns required during
removal so the cylinder can be reinstated to the same
point.

Convenience tool JDG-37 (servo sleeve special

socket set) may be used to aid in removing servo
cylinders.

IMPORTANT: Exact number of turns must be

noted and used on reassembly or motor will not
have proper output speed and crawler will mis-
track.

l-Nut 3-Servo Stop

2-Servo Cylinder 4-Depth Micrometer

Fig. 93-Servo Stop Replacement

NOTE: In most cases it will not be necessary to

disassemble the motor any further. However, the re-
maining disassembly procedure should be used if it is
necessary to disassemble the servo pistons or swash-
p/ate.

NOTE: Support swashplate before removing trun-

nions. Cocking of trunnion bearings may occur if
swashplate is not supported.

Scribe a line on both trunnions and motor housing

and mark trunnions and housing to facilitate correct
assembly of trunnions after servicing the motor. The
l-Upper Servo Piston 4-Upper Servo Cylinder trunnions cannot be interchanged.
2-Special Stop Screw !&Lower Servo Piston
3-Servo Stop GLower Servo Cylinder Remove trunnions by placing a screw or pull ham-
mer in the threaded center hole of the trunnion and
Fig. 92-Servo Cylinders Removed ( -296266)
pulling.

IMPORTANT: Do not remove stop (3, Fig. 92) NOTE: Do not pry the trunnion.
from upper servo cylinder (4) or special stop screw The trunnion bearings are “slip fit.” If they are to be
(2) from upper servo piston. This stop is factory removed, do not use a puller or a pry bar. Keep the
adjusted and will cause mistracking if altered. bearing shims with each trunnion.
NOTE: After S.N. 296286 Special stop screw and Remove swashplate and servo piston assembly
servo stop are used in both upper and lower cylinders from the motor housing.
and pistons.

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-44 Transmission Hydraulics TM- 1136 (Apr- 79)

The servo piston assemblies (4, Fig. 94) may be

removed from the swashplate (1) by removing the snap
rings (2) and pins (3). These pins are press fit so you
will need to drive them out carefully.

The swashplate control link (5) may be removed by

removing the pin (6) and snap ring (7).

NOTE: If servo pistons are removed from the

swashpla te, keep each piston with its respective cylin-
der.

t-Swashplate 5-Control Link

2-Snap Ring (2 used) 6-Pin
3-Pin 7-Snap Ring
4-Servo Piston

Fig. 94-Servo Piston Removed

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Apr- 79) Transmission Hydraulics 0360-45

‘\ 7 66 52
\
\ \

l-Cap Screw (6 used) 19-Piston Retainer 37-Gasket 56-Gasket

2-Trunnion (2 used) 28-Ball Guide 38-Shim 56-Front Cover
3-Shim (Use as required) Pl-Spring (6 used) 39-Rear Bearing 57-Cap Screw (12 used)
4-O-Ring (2 used) 22-Cylinder Block 46-O-Ring %-O-Ring (2 used)
Cfrunnion Bearing (2 used) 23-Pin 41-Machine Screw (4 used) 59-Rotating Seal
6-Motor Housing 24-Spring Seat 42-Servo Retainer (2 used) 6kStationary Seal
7-Snap Ring (4 used) 25-Spring 43-Servo Cylinder 61-O-Ring
&Pin (2 used) 26Spring Guide 44-Servo Piston 62-Spring (6 used)
9-Servo Piston 27-Spring Retainer 45-Control Link 63-Seal Retainer
W-O-Ring (2 used) 28-Retaining Ring 46-Snap Ring 64-Snap Ring
11-O-Ring (2 used) 29-Bearing Plate Pilot 47-Pin 65-Shaft Seal Kit
12-Stop 36-Bearing Plate 48-Swashplate 66-Filter Screen (2 used)
13-O-Ring 31-Valve Plate 49-Motor Shaft 87-Stop (296287- )
W-Servo Cylinder 32-Gap Screw (2 used) 50-Shim 68-stop
15-Nut 33-Retainer 51-Front Bearing 69-O-Ring (2 used)
W-O-Ring 34-Cover 52-Fitter Screen f&-Special Nut
17-Thrust Plate 35-Cap Screw (8 used) %-O-Ring (2 used)
W-Piston Assembly (9 used) 36End Cap 54-Plug (2 used)

Fjg. 95-Exploded View of Variable Displacement Motor (R.H. Transmission)

Litho in U.S.A.
 3 Transmission JD750 Crawler Bulldozer
0360-46 Transmission Hydraulics TM- 1136 (Apr- 79)

INSPECTION
Wash all parts in diesel fuel and dry thoroughly. Coat
I all parts with clean hydrostatic fluid.

IMPORTANT: Be very careful when handling

these parts during washing, drying and inspection.

NOTE: To dry parts after washing in diesel fuel,

shake off excess liquid and blow dry wifh clean com-
pressed air. DO NOT wipe dry with rags or .paper
towels.

Inspect all surfaces for excessive wear, nicks,

scratches, or scoring.

Inspect second land from the outside of the piston

l-Motor Shaft 3-Stamped “S” on
slippers for nicks or scratches. l--Rotating Seal Short Shaft

Bearing races in swashplate should be inspected for Fig. 96-Critical Surfaces of Motor Shaft
wear or brinnelling. If brinnelling causes jerky swash- and Rotating Seal
plate movement, the bearing should be replaced.
ASSEMBLY
Excessive wear on the valve plate, bearing plate,
and ball guide should be checked closely. NOTE: Be certain to install new O-rings and gas-
kets when assembling the motor.
Inspect splines for wear or galling.
Have a small can of hydrostatic fluid and a container
Be certain all bearings rotate freely. of petroleum jelly available. Apply a light coat of hy-
drostatic fluid to each surface prior to assembly. Apply
IMPORTANT: Use only JD bearings ordered by a light coat of petroleum jelly to all O-rings prior to
specific part number as they are selected for close assembly.
tolerances and bearing manufacturer’s numbers
may be the same but not matched to the necessary Refer to Fig. 95 (exploded view) and if any of the
close tolerances. parts listed below have been replaced, it will be nec-
essary to check drive shaft end play before completely
Inspect the surface of the motor shaft (1, Fig. 96) assembling the motor.
and the surface of the rotating seal (2) for nicks or
scratches. These parts are:

6-Motor Housing 49-Motor Shaft

36-End Cap U-Front Bearing
39-Rear Bearing %--Front Cover

To check end play, assemble the above parts and

end cap gasket (37) and front cover gasket (55), being
certain bearing cones are down to shaft shoulders and
bearing cups are properly seated. Tighten end cap and
front cover bolts 36 to 38 lb-ft (49 to 52 Nm) (5.0 to 5.3
kg-m) torque, then check drive shaft end play.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Transmission Hydraulics 0360-47

NOTE: If the front bearing has been removed, in- Apply a light coat of hydrostatic fluid to the inside of
spect shaft to see if it is marked “S. ” (3, Fig. 96) If it is, the servo cylinders and put two new O-rings on each I
a 0.070 inch (0.25 mm) shim must be placed between cylinder.
the shaft shoulder and bearing prior to the bearing
being pressed on the shaft. NOTE: If new upper servo cylinder is installed, it will
be necessary to measure depth of stop and replace it
End play of the motor shaft (49, Fig. 95) must be in new servo cylinder. Measure depth with depth mi-
0.006 to 0.016 inches (0.15 to 0.41 mm). If the end play crometer and install stop in new cylinder Drecisely (Fig.
is less than 0.006 inches (0.15 mm), use two end cap 97).
gaskets (37) on the end cap (36).

If the end play of the drive shaft exceeds 0.016

inches (0.41 mm), use one shim (38) under the cup of
the rear bearing (39) in the end cap (36). Each shim is
0.010 inch (0.25 mm) thick.

NOTE: End play can be checked with the swash-

plate and servo cylinders installed.

Once the correct end play has been established,

disassemble these pieces and proceed with the com-
plete assembly of the motor as follows:

Cover servo pistons (4, Fig. 94) and swashplate (1) 3

2451408 d
with hydrostatic fluid. Assemble servo pistons to
l-Nut %-Servo Stop
swashplate by pressing pins (3) into swashplate links
2-Servo Cylinder 4-Depth Micrometer
and secure snap rings (2) to pins. Be careful not to nick
piston or swashplate surfaces. Fig. 97~Servo Sfop Replacement

Assemble control link (5) to swashplate. Screw cylinders into motor housing counting the
number of turns. Insure that the correct servo cylinder
Install swashplate in motor housing. Tip swashplate goes into the correct bore in motor housing.
and place control link so it can be reached through the
control valve opening. IMPORTANT: insure that the cylinder is
screwed in the exact number of turns as when it
Apply light coat of hydrostatic fluid to trunnion bear- was removed or the motor will not have proper
ings and trunnions. Install trunnion assemblies with output speed and crawler will mistrack.
new O-rings in motor housing. The swashplate should
have 0.002 to 0.004 inches (0.05 to 0.10 mm) preload Align scribe lines (3, Fig. 91) on cylinder and motor
3-l /2 to 6-l /2 pounds (16 to 29 N) (2 to 3 kg) pull on housing precisely. Correct alignment of scribe lines is
swashplate control link when using pull gauge). necessary to place the swashplate for proper output
speed.
NOTE: Be certain to install correct trunnion in cor-
rect side of housing. NOTE: When new servo cylinders are installed, the
precise number of turns is essential for the motor to
NOTE: If new trunnion bearings or swashplate has have proper output speed.
been installed, it will be necessary to adjust shim
packs. There should be not more than 0.008 inches Install servo cylinder retainers with socket head
(0.20 mm) difference in shim packs between sides. screws. Depress retainer into servo cylinder slot to
prevent cylinder rotation.
Tighten cap screws.

Litho in U.S.A.
 3 Transmission JD 750 Crawler Bulldozer
0360-48 Transmission Hydraulics TM- 1136 (Nov-78)

Install new gasket on displacement control valve (1,

Fig. 88). Slide valve feedback arm pin (2) into swash-
plate control link (3).

Install eight cap screws and washers in valve and

tighten to 10-l 1 lb-ft (14-15 Nm) (1 to 2 kg/m) torque.

NOTE: One cap screw has a tighter fit since it is

used for valve alignment.

If front bearing has been removed, press a new

bearing on the shaft.

IMPORTANT: Use only JD bearings ordered by

specific part number as they are selected for close
tolerances and bearing manufacturer’s numbers
T45090N
may be the same but not matched to the necessary
close tolerances. l-Nut (2 used) 3-Swashplate Stop (2 used)
2-Front Cover 4-Depth Micrometer
NOTE: Prior to pressing bearing onto shaft, inspect
Fig. 98-Swashplate Sfop Replacement
shaft to see if it is marked “S.” (3, Fig. 96) If it is, a
0.010 inch (0.25 mm) shim must be placed between
Install new gasket on front cover and move housing
the shaft shoulder and the front bearing prior to press-
to front cover. Install shaft and bearing assembly
ing the bearing on the shaft.
through the cast hole in swashplate. Align the locating
IMPORTANT: Insure that bearing does not pins in the motor housing with the front cover and
damage sealing surface of shaft. install twelve cap screws. Tighten cap screws to 85 to
93 lb-ft (115 to 126 Nm) (12 to 13 kg/m) torque.
Remove the thrust plate.
Remove hoist from trunnion eyebolt.
Install an eyebolt in the top trunnion and attach
Lubricate the thrust plate with hydrostatic fluid and
overhead hoist to eyebolt.
install in swashplate. The chamfered side of the thrust
plate fits into the swashplate.
NOTE: If the front cover is replaced, the stop in the
, front cover must be placed in the new cover. Use a
NOTE: Do not nick or scratch the lapped surface on
depth micrometer and measure the depth of the stop
the thrust plate.
i and then place it in the new cover precisely (Fig. 98).
/
The cylinder block assembly should be installed
next. There is no special relationship of pistons, bores,
or springs; however, the alignment of the ball guide
and cylinder block splines is critical. The undersized
tooth in the spline of the cylinder block must line up
with the missing tooth in the ball guide spline.

These in turn line up with a missing tooth on the

shaft spline (Fig. 99).

bitho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-1 136 (Nov-75) Transmission Hydraulics 0360-49

NOTE: Use adapters (2, Fig. 101) on puller legs to

fit into cap screw holes in end cap.

NOTE: The rear bearing must be pressed on until it

rests firmly on the shoulder of the shaft to insure
adequate bearing clearance.

IMPORTANT: Use only JD bearings ordered by

specific part number as they are selected for close
tolerances and bearing manufacturer’s numbers
may be the same but not matched to the necessary
close tolerances.

Fig. 99-Motor Shaft Missing Tooth

Lubricate the thrust plate, pistons, piston slippers

and bores with hydrostatic fluid. Hold the shaft on the
external end, align the missing tooth of the shaft and
ball guide. Slide the cylinder block assembly onto the
shaft and against the thrust plate. When properly in-
stalled, a spring load can be felt when pushing against
the cylinder block.

Install the spring guide into the center bore of the

cylinder block (Fig. 100).

l-Rear Bearing 3-H-Bar Bearing Puller

2-Adapter 4-Special Tool, JD318

fig. 70 I-Rear Bearing installation

install the bearing plate pilot ring in the center bore

of the cylinder block.

Coat cylinder block side of bearing plate with hy-

drostatic fluid and install the bearing plate so the milled
slot locates over the pin in the cylinder block. After
installation, lubricate the exposed surfaces with clean
hydrostatic fluid.

Fig. 700-Spring Guide installation

Lubricate end cap face with hydrostatic fluid. Install
the valve plate on the end cap so the slot in the valve
Lubricate rear bearing with hydrostatic fluid.
plate locates over pin in end cap.

The rear bearing should be installed using an H-bar

bearing puller (3, Fig. 101). Press the bearing onto the
shaft with the center screw of the puller bar. A special
tool, JD318 (4), must be used between the center
screw and the rear bearing (1).

Litho in U.S.A.
 3 Transmission JO750 Crawler Bulldozer
0360-50 Transmission Hydraulics TM- 1136 (Nov-75)

Place a new end cap gasket (1, Fig. 102) on the If shaft seal assembly has been removed, install as
housing, being certain the locating pins (2) are in place. described below.

NOTE: If more than one gasket was removed dur-

Install new O-ring on rotating seal.
ing disassembly and the drive shaft, end cap, front
cover, or bearings were not replaced, it will be neces-
Install rotating seal (2, Fig. 103) using Special Tool
sary to replace the same number of gaskets as pre-
JD320 (1). Coat end of special tool with petroleum jelly
viously used.
and stick rotating seal to tool.
Install new O-rings (3) in the counterbore in the
IMPORTANT: This part is easily damaged and
housing.
care must be exercised when installing. Do not
allow seal to drag across shaft when installing, and
do not damage the seal lapped surface (3).

l-Special Tool JD320 3-Lapped Surface

2--Rotating Seal

Fig. 703~Rotating Seal and Special Tool

Seat seal firmly on drive shaft (Fig. 104).

l-End Cap Gasket 3-O-Ring

P-Locating Pins (2 used)

Fig. IO,?-End Cap Gasket and O-Ring lnsfallation

IMPORTANT: Use extreme care when assem-

bling cylinder block, valve plate, bearing plate, and
end cap to avoid dropping, nicking or scratching
lapped surfaces.

If any of these parts are damaged, they wilt, have to

be replaced with new parts. Fig. 104~Rotating Sea/ Installation

Use overhead hoist to install end cap with valve

Install six springs in seal retainer. Install new O-ring
plate to motor housing.
between stationary seal and seal retainer and locate
IMPORTANT: Do not let valve plate fall away stationary seal in seal retainer by locating notch in seal
from end cap during assembly. with pin in retainer. Coat retainer O-ring with petroleum
Tighten opposite cap screws to be certain end cap jelly and install on seal retainer.
seats properly. Tighten cap screws to 170 to 185 lb-ft
(230 to 251 Nm) (24 to 26 kg/m) torque. Coat O-ring chamfer in front cover bore with petro-
leum jelly and install seal assembly using Special Tool
JD320 (Fig. 105). Do not damage seal assembly dur-
ing installation.

i Litho in U.S.A.
,. .. _,-. . .I
i; *
JD750 Crawler Bulldozer Transmission 3
TM-1 136 (Nov-75) Transmission Hydraulics 0360-51

IMPORTANT: Care must be taken to insure that Install snap ring using snap ring pliers. Snap ring
spring load does not disengage stationary seal must be installed with chamfered side away from shaft
from seal retainer pin during installation. seal assembly.

If the unit has been properly assembled, the motor

shaft should rotate with 26 to 38-l /2 lb-ft (35 to 52 Nm)
(4 to 5 kg/m) torque, after breakaway.

Torque readings outside these specifications war-

rant investigation for correct assembly.

INSTALLATION
The pump must be assembled to the motor prior to
the transmission being installed in the unit; see Pump
Installation, this group.

After pump is assembled to motor, see Transmis-

sion Installation, this group.

fig. 705-Shaff Seal hsfallafion

.Y
.
Litho in U.S.A.
-7.
 3 Transmission JD750 Crawler Bulldozer
0360-52 Transmission Hydraulics TM-l 136 (Nov-75)

DISPLACEMENT CONTROL VALVE

REMOVAL
The displacement control valve may be removed
from the motor housing without removing the trans-
mission from the crawler.

When removing the displacement control valve, be

certain to thoroughly clean the outside of the trans-
mission. Either steam clean or wash with diesel fuel. If
internal work is to be performed on the control valve,
insure that the work bench, tools, and equipment are
clean.

Drain the hydrostatic reservoir.

Mark lines going to control valve and the fittings so

proper lines are connected on reassembly.

Remove lines and immediately cap lines and fittings

with clean plugs.
l-Bleed Screw 3-Control Valve
2-O-Ring
Remove eight cap screws which secure valve as-
sembly to motor housing. Fig. 706~Bleed Screw Removed

Pull valve away from motor housing and slide feed-

back arm pin out of swashplate control link (Fig. 88).

Remove valve assembly and gasket.

NOTE: Cover opening in motor housing to keep out

dirt while servicing valve.

REPAIR
Remove bleed screw from valve housing (Fig. 106).

Remove jam nut (1, Fig. 107) washer (2), and

indicator arm (3) from indicator assembly.

The indicator shield (4) does not need to be re-

moved to remove the indicator sleeve (6). Use channel
lock pliers and remove assembly.

Shield (4) and felt packing (5) can be removed from

sleeve (6).
l-Jam Nut !&Felt Packing
2-Washer 64ndicator Sleeve
34ndicator Arm 7-O-Ring
4-Shield &-O-Ring

Fig. 107-Swashplate Indicator Assembly

Litho in U.S.A.
.. -
JD750 Crawler Bulldozer Transmission :.;’ 3
TM-l 136 (Feb-77) Transmission Hydraulics ? 0360-53
??,
e
The spool and sleeve assembly of the displacement INSPECTION ;
control valve can be disassembled for cleaning pur-
Clean all parts in diesel fuel and dry &th com-
poses only. Care must be taken when working in this ‘.
pressed air. t
valve, since damage to the valve and sleeve assembly
or to the internal operating mechanism will cause re-
Inspect all parts for excessive wear or scoring.
placement of the entire valve.
If spool and sleeve assembly needs to be replaced,
Refer to Fig. 108 for areas within the valve where
replace the entire valve.
disassembly for cleaning can be done.
Coat all parts with hydrostatic fluid if there is any
IMPORTANT: Alterations to the operating
time delay prior to assembly.
mechanism within the valve cannot be made.
ASSEMBLY
Refer to pump assembly.

NOTE: Be certain to install new O-rings and gas-

kets when assembling displacement control valve.

Be certain all parts are clean and dry.

Apply a light coat of hydrostatic fluid to all parts prior

to assembly.

Install new O-ring on bleed screw and install in

housing.

INSTALLATION
Install new valve gasket on housing. Slide valve
feedback arm pin into swashplate control link.

Install eight cap screws and washers in valve and

tighten to 10 to 11 lb-ft (14 to 15 Nm) (1 to 2 kg/m)
torque.
l--Do Not Alter ~--DO Not Alter
~--DO Not Alter !&-May Be Removed
3-May Be Removed ~-DO Not Alter After valve is mounted on motor, set indicator to the
“F” position and tighten jam nut.
Fig. 108-Working Areas Within Valve

The removal of the sleeve and spool assembly for

the motor displacement control valve is the same as for
the pump displacement control valve. Refer to the
pump displacement control valve disassembly, this
group.

NOTE: Drive sleeve and spool assembly out of the

housing.

Be careful not to nick or scratch the spool and sleeve

surfaces.

Litho in U.S.A.
-. ‘>,.&
3 Transmission JD750 Crawler Bulldozer
0360-54 Transmission Hydraulics TM- 1136 (Feb- 77)

24 5

18
\
T43221

l-Cap Screw (3 used) &Set Screw 15-Indicator 22-B&d Screw

2-End Cap g--Valve Housing 1 GWasher 23-O.Ring
3-Gasket 1 O-Plug 17-Shield 24-Plug
4-Washer (2 used) 1 l-O-Ring M-Nut 25-Spool and Sleeve Assembly
5-Spacer 12-O-Ring 19-Washer (8 used) 26-O-Ring
6-Gap Screw 13-Indicator Sleeve PO-Cap Screw (8 used) 27-Plug
‘/-Control Valve Gasket 14-Felt Packing 21-O-Ring 2S--Spring Pin

Fig. 109-Motor DisplacementControl Valve (Exploded View)

bitho in U.S.A.
JD750 Crawler Bulldozer ?ransq&sion 3
TM-l 136 (Nov-78) Transmission Hydra&i& 0360-55

MANIFOLD VALVE ASSEMBLY DISASSEMBLY

The motor manifold assembly may be removed Refer to Fig. 111. Remove shuttle valve plugs (8).
without removing the transmission. The hydrostatic Remove springs (lo), washers (1 l), and shuttle valve I
reservoir must be drained. spool (14).

Before removing the manifold, thoroughly clean the Remove charge relief valve plug (15), spring (17),
outside of the transmission. Either steam clean or and piston (18). There are shims (16) inside the plug.
wash with diesel fuel. Do not misplace or alter these shims.

If internal service work is to be performed on the Remove high pressure relief valves (3) from both
manifold, keep the work bench, tools, and equipment sides of manifold. Be certain to place wrench on
clean. hexagon section of valve.

REMOVAL The high pressure relief valve may be disassembled

for cleaning purposes and to adjust the pressure set-
ting. There are shims (2) inside the O-ring plug.

INSPECTION
Clean all parts in diesel fuel and dry thoroughly with
compressed air.

Check all parts for excessive wear or scoring. Re-

place parts as necessary.

NOTE: If high pressure relief valve is defective, it

must be replaced. The plug shims (2, Fig. 111) are the
only service part for this valve. The relief valve can be
reshimmed to correct pressure setting.

Install new O-rings and backup washers on plugs

and relief valves before assembly.

If shuttle valve spool (14) needs to be replaced, the

l-Transmission Motor 4-Shuttle Valve
manifold housing (20) must also be replaced.
2-Manifold !5-Charge Relief Valve
3-Reverse High Pressure 6-Forward High Pressure ASSEMBLY
Relief Valve Relief Valve
Install high pressure relief valves in manifold.
Fig. 170~Motor Manifold Valve Assembly Tighten to 17-23 lb-ft (23-31 Nm) (2-3 kg/m) torque.

Remove six cap screws and washers and remove Install charge relief valve piston (18, Fig. 11 l),
manifold (Fig. 110). spring (17) and plug (15) with O-ring. Tighten plug
securely.
NOTE: It is not necessary to remove transmission
to service manifold. Plug holes in motor end cap im- Install shuttle valve spool (14), washers (1 1), springs
mediate/y to minimize oil loss. (lo), and plugs (8) with O-rings. Tighten plugs se-
curely.
NOTE: Transmission high pressure relief valves are
labeled Forward and Reverse. IMPORTANT: Shims are used with the relief
valves. Make sure shims are installed in plugs
A container should be available to catch any oil that used with relief valves.
drains from the motor when the manifold is removed.

Litho in U.S.A.
 3 Transmission
JO 750 Crawler Bulldozer
0360-56 Transmission Hydraulics
TM-1 136 (NOW78)

l-O-Ring (2 used) G--Plug (2 used) N-Plug

P-Shim Kit g-O-Ring (3 used) G-Shim
%-High Pressure Relief Valve (2 used) lO-Shuttle Valve Spring (2 used) 17-Relief Valve Spring
4-O-Ring (2 used) 11-Washer (2 used) l&Charge Relief Valve Piston
5-Backup Ring (4 used) 12-Test Port Plug (3 used) 19-O-Ring (2 used)
6-O-Ring (2 used) 13-O-Ring (3 used) 20-Manifold Housing
7-Relief Valve Seal Kit 14-Shuttle Valve Spool 21-O-Ring
22-Backup Washer (2 used)

Fig. 11I-Exploded View of Manifold Valve Assembly

INSTALLATION IMPORTANT: DO NOT START ENGINE AT THIS

Install new O-rings (19 and 21, Fig. 111) in face of TIME. REFER TO PROCEDURE 1, ADJUSTMENT
manifold. Install two backup washers (22) (flat side out) SECTION, GROUP 9026.
on top of O-rings (19) in two main ports of manifold.
Backup washers should be against face of motor end
cap when manifold is installed.

Attach manifold to end cap of motor. Tighten six cap

screws.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- I 136 (Nov- 75) Transmission Hydraulics 0366-57

TRANSMISSION CONTROL Cleanliness

VALVE It is essential that the working area be clean. Con-
tamination of any type within this valve will shorten the
expected life of its parts or cause malfunction of its
components.

Before removing the transmission control valve, re-

move floor boards and thoroughly clean the transmis-
sion control valve. Either steam clean or wash with
diesel fuel.

When internal work is to be performed on the control

valve, be sure to thoroughly clean the work bench,
tools, and equipment. ’

Replacement Parts
When servicing the valve, always install new O-
rings, backup washers, spring pins, and gaskets. q
Fig. 112-Transmission Control Valve

GENERAL INFORMATION
The transmission control valve is below the floor
boards. It houses the right and left steering control
valve, the FNR (Forward - Neutral - Reverse) valve,
the automatic control valve, the over pressure relief
valve, the pressure regulator valve, the speed control
valve, the automatic control valve shut-off valve, and
the automatic control valve variable orifice valve.
3 Transmission JDsCrawler Bulldozer
0360-58 Transmission Hydraulics TM- 1136 (Now75)

REMOVAL Remove cross shaft support cap screws and remove

cross shaft assembly (9).
Remove floor boards.
Disconnect all control valve lines and cap all lines
Disconnect the forward and reverse speed control
and fittings in valve.
linkage (1, Fig. 113), the engine speed control linkage
(2), the engine speed control cable (3), the FNR speed
control lever linkage (4), and the automatic control
valve variable orifice lever linkage (8).

l-Forward and Reverse Speed Control Linkage 5-L.H. Steering Valve Lever
2-Engine Speed Control Linkage &Automatic Control Valve Shut-Off Valve Linkage
3-Engine Speed Control Cable 7-R.H. Steering Valve Lever
4-FNR Speed Control Lever &Automatic Control Valve Variable Orifice Lever
%-Cross Shaft Assembly

Fig. 7 13-Transmission Control Valve Linkage

Litbo in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-l 136 (Nov-75) Transmission Hydraulics 0360-59

Disconnect right and left steering valve linkage (5

and 7, Fig. 113).

Disconnect automatic control valve shut off valve

linkage (6).

Remove cap screws and lift control valve from unit.

DISASSEMBLY

l-Reverse Direction 8-Left Steering Valve 13-Right Steering 19-P9 Test Port Plug
Lever Stop Screw Stop Screw Valve Stop Screw PO-Low Variable Orifice
2-Forward Direction (Internal Lever Stop) (Internal Valve Stop) Stop Screw
Lever Stop Screw g--Automatic Control 14-Right Steering 21-High Variable Orifice
3-FNR Speed Control Lever Valve Cartridge Valve Lever Stop Screw
4-P6 Test Port Plug 1 &-Automatic Control 15-P2 Test Port Plug 22-Right Steering Valve
5-P5 Test Port Plug Valve Adjustment 16P7 Test Port Plug Bore Plug
6-Left Steering Screw 17-P8 Test Port Plug 23-Automatic Control Valve
Valve Lever 11-P4 Test Port Plug l&Automatic Control Accumulator Piston Bore
7-Pl Test Port Plug 12-P3 Test Port Plug Valve Variable Orifice Plug
Lever 24-Left Steering Valve
Bore Plug

Fig. 7 14-Transmission Control Valve

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-60 Transmission Hydraulics TM- 1136 (Nov-75)

r-P1 Over Pressure Relief Valve 7-Left Steering Valve Stop Screw 1 l-Pressure Port
2-Right Steering Valve Stop Screw S-Automatic Control Valve Shut- 12-To Port X on Right Pump
3-P2 Pressure Regulator Valve off Valve Control Valve (Forward
4-P3 Speed Control Valve Adjustment %-To Port H on Left Pump Control Control Circuit)
S-Automatic Control Valve Adjust- Valve (Reverse Control Circuit) 13-To Port H on Right Pump
ment Screw and Cartridge lg.-To Port X on Left Pump Control Control Valve (Reverse)
6-FNR Valve Bore Plug Valve (Forward Control Circuit) Control Circuit)
14-Drain Port

Fig. 115-Transmission Control Valve

IMPORTANT: The transmission control valve

uses highly precision machined parts. Do not drop
or scratch parts. Keep individual valve parts to-
gether as they are removed.

Litho in U.S.A.
 JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Transmission Hydraulics 0360-61

l-Plug 4-Spring
2-O-Ring !&Valve Poppet I
l-Plug 4-Spring 3-Shim (Use as Required)
P-O-Ring S-Valve Poppet
3-Shim (Use as Required) Fig. 117-P2 Pressure Regulator Valve

Fig. 116-Pl Over Pressure Relief Valve

P2 Pressure Regulator Valve
Pl Over Pressure Relief Valve Remove plug (1 9 Fig. 117) O-ring (2) and shim or
shims (3).
Remove plug (1, Fig. 116), O-ring (2), and shim or
shims (3).
Remove spring (4) and valve poppet (5).

1 Remove spring (4) and valve poppet (5).

IMPORTANT: The Pl valve poppet and spring

and the P2 valve poppet and spring are different
and must not be interchanged.

Machines above Serial Number 266819 are shipped

with common Pl and P2 relief valve poppets installed.

When replacing these poppets on any machine

common Pl and P2 poppets may be used with any
machine.

Litho in U.S.A.
3 Transmission JD750 C& wler Bulldozer
0360-62 Transmission Hydraulics TM-1 136 (Nov-78)

Automatic Control Valve

Using a 9/l 6” Alien wrench, remove automatic con-
trol valve accumulator bore plug (4, Fig. 119) from
valve.

Remove P9 pressure test port plug (5) and with a

wooden dowel inserted in P9 test port (1) push spring
(2) and accumulator piston (3) out of its bore.

l-O-Ring 3-O-Ring
2-Plug 4-Valve Spool

Fig. 7 Id-Automatic Control Valve Shutoff Valve

l--P9 Test Port 4-Accumulator Bore Plug
P-Spring S-49 Pressure Test Port
Automatic Control Valve Shutoff Valve
3-Accumulator Piston Plug
Remove plug (2, Fig. 118), O-ring (3), and valve
spool (4) assembly. Fig. 119-Automatic Control Valve Accumulator

Remove valve spool (4) from plug (2). Remove cap screws (1, Fig. 120) and locking plate
(2).
Remove internal O-ring (1) from special plug (2).
Using channel lock pliers, remove cartridge with
adjusting screw (3), spring (4), and automatic control
valve spool (5).

IMPORTANT: The automatic control valve spool

and spring will come out with the cartridge and
care must be taken not to drop the spool.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-1 136 (Nov-78) Transmission Hydraulics 0360-63

l-Cap Screw (2 used) 3-Caftridge with 4-Spring G-Automatic Control Valve

2-Locking Plate Adjustment Screw 5-Automatic Control Piston
Valve Spool I-Valve Sleeve

Fig. 120-Automatic Control Valve Removal

Install wooden dowel through accumulator bore and

push automatic control valve piston and valve sleeve
out of the automatic control valve bore.

IMPORTANT: Be careful not to drop or scratch

parts.

The automatic control valve cartridge and spool are

a matched set. If one part is replaced, the other must
also be replaced.

The automatic control valve cartridge can be disas- l-Nut 4-O-Ring

sembled to service the adjustment screw (Fig. 121). l-Adjustment Screw 5-Cartridge
3-O-Ring

Fig. 121-Adjustment Screw Removal

Litho in U.S.A.
3 Transmission JD9’50 Crawler Bulldozer
0360-64 Transmission Hydraulics TM- 1136 (Nov-78)

l-Left Steering Valve 2-Right Steering Valve

Orifice (2 used) Orifice (2 used)

Fig. 123-Steering Valve Orifices

l-P9 Pressure Test 3-Orifice (2 used)
Port 4-P9 Pressure Test
P-Screen Filter Port Plug

Fig. 122-Automatic Control Valve Orifices

Remove two orifices (3, Fig. 122) from pressure test

port (1) with 7/32” Allen wrench.

Remove screen filter (2) with a small wire with a loop

on the end. Filter is non-magnetic.

NOTE: Replace filter. Do not attempt to clean it.

If orifices are not cleanable with compressed air,

replace them.

Steering Valve Orif ices

Remove pressure test port plugs P5, P6, P7, and
P8.

Use a number 8 Bristo multiple spline wrench and

remove the right and left steering valve orifices (Fig.
123).

NOTE: Do not interchange these orifices. The ori-

fices must go back into the bore they came from,
because the orifices can be of different sizes.

Clean the orifices with diesel fuel and blow dry with
clean compressed air.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Transmission Hydraulics 0366-65

Automatic Control Valve Variable Orifice Remove nut (12, Fig. 125).

Remove cap screws (1, Fig. 124) and remove vari-

Remove override lever spring (11) and sleeve (10).
able orifice assembly (2) from the transmission control
valve.
Remove override lever (9), variable orifice lever (8),
stop (7), spacer (6) and lock plate (5).

Carefully push variable orifice valve (1) out of hous-

ing (3).

l-Cap Screw (2 used) l-variable Orifice Assembly

Fig. 124-Variable Orifice Assembly Removal

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 -
3 Transmission JD750 Crawler Bulldozer
0360-66 Transmission Hydraulics TM- 1136 (Nov-78)

1-Variabfe Orifice Valve CLock Plate g--Override Lever

2-O-Ring 6-Spacer W-Override Lever Sleeve
3-Variable Orifice Housing 7-stop Ii-Override Lever Spring
4-O-Ring &Variable Orifice Lever 12-Nut

FQ. 125-Variable Orifice Components

Litho in U.S.A.
JD 750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Transmission Hydraulics 0360-67

l-Port Plate 3-Control Valve Housing 5-Control Valve Cover

2-Valve Housing Gasket 4-Cover Gasket GMounting Cap Screws

fig. 126-Transmission Control Valve Assembly

Transmission Control Valve Assembly

Remove control valve cover cap screws.

Remove control valve cover (5, Fig. 126), cover

gasket (4) and port plate (1).

Remove the valve housing gasket (2).

Steering Valve
IMPORTANT: When working on steering valves,
be sure that the parts for the respective valves stay
together and are returned to the same bore in the
transmission control valve housing.

Remove cap screws (4, Fig. 127).

Remove steering valve lever assembly (3).

Remove link (2).

i-Steering Valve Spool 3-Steering Valve Lever
(2 used) Assembly (2 used)
2-Link (2 used) 4-Cap Screw (4 used)

Fig. 127-Steering Valve Lever Assembly

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 3 Transmission JD750 Crawler Bulldozer
0360-68 Transmission Hydraulics TM-1 136 (Nov-78)

l-Link (2 used) 5-O-Ring (2 used) &Spacer (2 used)

P-Spring Pin (2 used) 6-O-Ring (2 used) g-Control Shaft Handle (2 used)
3-Steering Lever (2 used) 7-Steering Valve Lever IO-Nut (2 used)
4-Steering Control Shaft Housing

Q Fig. 128-Steering Valve Lever Components

Remove nut (10, Fig. 128) control shaft handle (9) FNR Valve
and spacer (8).
Remove nut (1, Fig. 130), FNR control shaft handle
(2), control stop (3), spacer (4) and bushing (5).
Carefully pull control shaft (4) from steering valve
lever housing (7).
Remove plug (7) and O-ring (8).

Remove steering lever (3) from shaft (4) by driving

Drive out spring pin (9) in speed control valve cam
out spring pin (2).
(10).
Remove steering valve bore plug (7, Fig. 129).
Drive the spring pin (10, Fig. 132) in the FNR valve
lever (14) into the control shaft (12).
Remove stop (6), spring (5) and valve spool (4).

IMPORTANT: The spring pin (2, Fig. 131) cannot

NOTE: Do not nick or scratch the steering valve
be driven all the way out of the lever (3) and shaft
spool. It can be removed for cleaning purposes only. If
(1). There is not enough clearance (5) below the
a steering valve needs to be replaced, the entire
shaft. Drive the spring pin into the shaft being
transmission control valve assembly must be replaced.
careful not to drive it into the lever on the other
side (see Fig. 131).
Using diagonal cutters, remove spring pin (3).
Remove the FNR valve link (13, Fig. 132).
NOTE: Replace spring pin (3) when removed, since
it is also used as a locating pin for the housing and port
NOTE: Record the part number on this link in case
plate.
the link is misplaced.

Cut a piece of 3/4” (19 mm) round bar stock (2) to

2-l/8” (54.0 mm) length.

Insert round bar stock in housing behind valve

sleeve and use a screwdriver (1) as a lever to push out
the valve sleeve.

Litho in U.S.A.
JO750 Crawler Bulldozer Transmission 3
TM-l 136 (Nov-78) Transmission Hydraulics 0360-69

l-Screwdriver 4-Valve Spool (2 used) 7-Steering Valve Bore Plug (2 used)

2-314” x 2-i/8” Round Bar 5-Spring (2 used) 8-O-Ring (2 used)
3-Spring Pin (2 used) GStop (2 used)

Fig. 129-Steering Valve Sleeve Removal

l-Control Shaft 4-Valve Housing

2-Spring Pin 84nsufficient Clearance
3-FNR Valve Lever for Spring Pin

Fig. 131-FNR Valve Lever Spring Pin

l-Nut 4-Spacer 8-O-Ring

P-FNR Control S-Bushing %-Spring Pin
Shaft Handle t&O-Ring 1 O-Speed Control
3--control Stop 7-Plug Valve Cam

Fig. 130-FNR Lever Removal

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3 Transmission JO750 Crawler Bulldozer
0360-70 Transmission Hvdraulics TM-l 136 (Nov-78)

NOTE: Do not nick or scratch the FNR valve. It can

be removed for cleaning purposes only. If the FNR
valve needs to be replaced, the entire transmission
control valve assembly must be replaced.

Speed Control Valve

l-Nut l&-Spring Pin (FNR

2-PNR Control Shah Valve Lever)
Handle 1 l-O-Ring
3-Control Stop 12-Control Shaft
4-SpaCW 13-FNR Valve Link
g-Bushing 14-FNR Valve Lever
6-O-Ring 15-Speed Control Cam
7-Plug 16-FNR Valve
&O-Ring 17-O-Ring
g-Spring Pin (Speed l&FNR Valve Bore Plug
Control Cam)
l-Adjustment Screw s-Valve Seat
Assembly 7-Speed Control
Fig. 732-FNR Valve Removal
P-Special Plug Adjusting Spring
3-O-Ring &P3 Speed Control Spool
Remove the speed control cam (15, Fig. 132) and 4-Plunger g--Shim (Use as Required)
FNR valve lever (14) from the control shaft (12). S-O-Ring 1 O-Speed Control Spring

Fig. 133-Speed Control Valve Removal

Remove the control shaft (12).

NOTE: Drive the FNR valve lever spring pin (10) out
of the control shaft (12).

Remove the FNR valve bore plug (18) and push out
the FNR valve (16).

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Transmission Hydraulics 0360-71

Remove special plug (2, Fig. 133) with adjustment NOTE: Do not nick or scratch the speed control
screw assembly (1). sleeve or plunger. If the speed control sleeve needs to
be replaced, the entire transmission control valve must
Remove plunger (4), valve seat (6) and speed con- be replaced.
trol adjusting spring (7).
REPAIR
Remove P3 speed control valve spool (8), shim or
Inspect all parts and replace as necessary.
shims, (9) and speed control spring (10).

The following parts of the transmission control valve

NOTE: When spool is removed, record shim pack
may be removed for cleaning purposes only. If they :
thickness in case shim pack is misplaced.
need to be replaced, the entire transmission control
valve must be replaced.
NOTE: Do not nick or scratch the P3 speed control
spool (8). It can be removed for cleaning purposes
These parts are the steering valve spools and
only. If the speed control spool needs to be replaced,
sleeves, the FNR valve spool, the speed control valve
the entire transmission control valve must be replaced.
spool, and the speed control sleeve.

Remove plug (1, Fig. 134).

Care must be taken not to nick or scratch these
parts.
Use special tool, JD325 (2), and remove speed
control sleeve (3) and speed control plunger (4).
There are also some parts in the transmission con-
trol valve that are made in two sizes. The standard size
part is not marked. The oversized part is stamped with
either an “A” or a ‘ID.” The transmission control valve
housing is also stamped with an “A” or a “D” when the
oversized part is to be used. This stamp appears by the
bore of the appropriate spool or sleeve.

These parts are the automatic control valve shutoff

valve spool, the variable orifice valve housing, the 1
automatic control valve accumulator piston, the au-
tomatic control valve sleeve, and the automatic control
valve spool and cartridge assembly.

If these parts are stamped with an “A” or “D” then

replace them with the appropriate part. If there is no
marking on the part, then replace them with the stan-
dard parts. See your parts catalog.

Install new O-rings, spring pins, and gaskets.

Clean all parts in diesel fuel and blow dry with clean
compressed air.

Prior to assembly coat all parts with hydrostatic fluid.

l-Plug 3-Speed Control Sleeve
2-Special Tool 4-Speed Control Plunger

Fig. 134~Speed Control Sleeve Removal

Litho in U.S.A.
 3 Transmission JD750 Crawler Bulldozer
0360-72 Transmission Hydraulics TM-l 136 (Nov-78)

ASSEMBLY Install shim or shims (3) in plug (1) and new O-ring
(2) on Plug (1).

Install plug.

After the transmission control valve is installed in the

unit, refer to procedure 7, adjustment section, Group
9026, for valve adjustment.

El

l-Plug Q-Spring
I 2-O-Ring
3-Shim (Use as Required)
5-Valve Poppet

Fig. 135-Pl Over Pressure Relief Valve

Pl Over Pressure Relief Valve

l-Plug 4-Spring
1 install valve poppet (5, Fig. 135) and spring (4). P-O-Ring E&Valve Poppet I
3-Shim (Use as Required)
Install shim or shims (3) in plug (1) and new O-ring
(2) on Plug (1). Fig. 136-P2 Pressure Regulator Valve
Install plug.
After the transmission control valve is installed in the
unit, refer to procedure 6, adjustment section, Group
9026, for valve adjustment.
IMPORTANT: The PI valve poppet and spring
and the P2 valve poppet and spring are different
and must not be interchanged.

Machines above Serial Number 266819 are shipped

with common Pl and P2 relief valve poppets installed.

When replacing these poppets on any machine

common Pl and P2 poppets may be used with any
machine.

P2 Pressure Regulator Valve

Install valve poppet (5, Fig. 136) and spring (4).

Litho in U.S.A.
JD 750 Crawler Bulldozer Transmission 3
TM-1 136 (Nov-75) Transmission Hydraulics 0360-73

Automatic Control Valve Shutoff Valve

Install new O-ring (3, Fig. 137) on plug (2) and new
O-ring (1) on plug (2).

Install valve spool (4) into plug.

Install valve assembly into control valve housing.

l-P9 Pressure Test 3-Orifice (2 used)

Port 4-43 Pressure Test
2-Screen Filter Port Plug

Fig. 738-Automatic Control Valve Orifices

l-O-Ring 3-O-Ring
2-Plug 4-Valve Spool

Fig. 137-Automatic Control Valve Shutoff Valve

Automatic Control Valve

Install new screen filter (2, Fig. 138) and orifices (3)
in P9 pressure test port (1).

Install new O-ring on plug (4) and install plug.

install spring (2, Fig. 139), accumulator piston (3)

and accumulator bore plug (4) with new O-ring.

l-P9 Test Port 3-Accumulator Piston

2-Spring 4-Accumulator Bore Plug
5-P9 Pressure Test Port Plug

Fig. 139-Automatic Control Valve Accumulator

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-74 Transmission Hvdraulics TM- 7 136 (Nov-751

Prior to assembling the remaining automatic control Automatic Control Valve Cartridge With Adjust-
valve components, refer to the following procedure to ment Screw (3, Fig. 140), Spool (5) and Spring (4).
check for sticking parts.
NOTE: The automatic control valve spool is sym-
metrical and can be inserted either way.
Automatic Control Valve Piston (6, Fig. 140) and
Sleeve (7).
With the automatic control valve cartridge, spool,
With the piston and sleeve assembly removed from and spring removed from the transmission control
the transmission control valve, separate’ the piston valve, separate the spool and the spring from the
and sleeve and wash both pieces in clean diesel cartridge. Wash all pieces in diesel fuel.
fuel.
NOTE: DO NOT blow pieces dry with air.
NOTE: DO NOT blow pieces dry with air.
With the cartridge, spring, and spool still wetted with
With the piston and sleeve still wetted with the diesel the diesel fuel, insert the spring and the spool in the
fuel, insert the piston in the sleeve. Turn the sleeve cartridge. Turn the sleeve end for end; the spool
end for end; the piston must with its own weight slide must with its own weight slide freely in the sleeve.
freely in the sleeve.

To check piston and sleeve for concentricity, repeat

previous step with piston rotated approximately go”,
180”, and 270” in the sleeve.

I-Cap Screw (2 used) 3-Cartridge with 4-Spring 6-Automatic Control

2-Locking Plate Adjustment Screw 5-Automatic Control Valve Piston
Valve Spool 7-Valve Sleeve

Fig. 140-Automatic Control Valve Installation

bitho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-1 136 (Nov-78) Transmission Hydraulics 0360-75

Reassemble the adjustment screw (2, Fig. 141) nut After the transmission control valve is installed in the
(l), and new O-rings (3 and 4) in the automatic control unit, refer to procedure 11, adjustment section, Group
valve cartridge (5). 9026, for valve adjustment.

Steering Valve Orifices

Install steering valve orifices (1 and 2, Fig. 143).

NOTE: Do not interchange these orifices. The ori-

fices must go back into the bore they came from.

Install test port plugs P5, P6, P7, and P8 with new
O-rings.

l-Nut 4-O-Ring
2-Adjustment Screw !+Cartridge
3-O-Ring

Fig. 14 l-Adjustment Screw installation

Install the automatic control valve piston (6, Fig.

140) in the valve sleeve (7) so that the small diameter
end of the piston sticks through the small hole in the
sleeve.
install this assembly in the automatic control valve
bore with the small diameter end of the piston toward
the accumulator bore.

Install the spring (4) and valve spool (5) in the

cartridge with adjustment screw (3).

Install the cartridge assembly in the valve housing.

Install locking plate (2) and tighten cap screw (1).

NOTE: Each time the automatic control valve lock- l-Left Steering Valve 2-Right Steering Valve
ing plate (1, Fig. 142) is removed, reinstall it so the Orifices Orifices
slight curve is toward the valve housing (2). Lay a
straightedge across the locking plate to determine the Fig. 743-Steering Valve Orifices
curved side.

I
P45165N

l-Locking Plate 2-Transmission Control Valve Housing

Fig. 142-Automatic Control Valve Locking

f/ate hstallation

Litho in U.S.A.
 3 Transmission JO 750 Crawler Bulldozer
0360-76 Transmission Hydraulics TM-l 136 (Nov-78)

Automatic Control Valve Variable Orifice

I

l-Variable Orifice Valve 5-Lock Plate g--Override Lever

2-O-Ring &Spacer lo-Override Lever Sleeve
3-Variable Orifice Housing 7-stop 1 i-Override Lever Spring
M-Ring S-Variable Orifice Lever 12-Nut

Fig. 144-Variable Orifice Assembly

install new O-ring (2, Fig. 144) on the variable orifice Rotate the valve in this direction until a dimension of
valve (1) and install the valve into the valve housing 0.400 inch (10.16 mm) measured from the outside
(3). edge of the windows to tne edge of the slot (1) is
recorded.
Hold the assembled variable orifice valve and
housing so the window (3, Fig. 145) in the valve Then, without moving the valve in the valve housing,
housing (4) faces straight up and the splined end of the hold the valve and housing assembly so the milled flat
valve (5) faces toward you. (1, Fig. 146) for the locking plate (2) faces to the left
side when looking at the splined end of the valve (6).
Rotate the valve (clockwise) in the valve housing so
the variable orifice slot (2) in the valve enters the
windows (3) in the valve housing from the left side.

hitho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-1 136 (Nov-78) Transmission Hydraulics 0360-77

-
-
-
-
-
B
T45178~
T45166N
l-Early Locking Plate 2-Valve Housing Milled Flat
14.406 inch (10.16 mm) “Variable Orifice
2-Variable Orifice Valve Slot Valve Housing
Fig. 147-Early Locking Plate Assembly
3-Variable Orifice Valve Housing !&Variable Orifice
Window Valve

Fig. 145-Variable Orifice Assembly

l-Valve Houslng Milled Flat 4-stop

24ocklng Plate !&Stop Ear
“Variable Orifice Lever 6-Valve Splined End T45179N

Fig. 146Stop and Lever Assembly l-Current Locking Plate P-Valve Housing Milled Slot

Fig. 148~Current Locking Plate Assembly

Litho in U.S.A.
3 Transmission JD 750 Crawler Bulldozer
0360-78 Transmis%ion Hydraulics TM- 1136 (Nov- 78)

Install locking plate. Steering Valve

install valve sleeve (6, Fig. 149) into transmission
NOTE: The locking plate for the variable orifice is
control valve. Install new spring pin (7) into spring pin
different between early units and current production
bore (8).
units. The two locking plates are assembled differently.

NOTE: If sleeve needs to be driven into housing, do

The early locking plate (1, Fig. 147) is assembled
not use a metal tool.
with the tab facing away from the transmission control
valve housing and against the milled flat (2) on the
IMPORTANT: When installing the spring pin for
variable orifice assembly.
the steering valve sleeve, orient the slit in the side
of the spring pin towards the outside of the’control
The current locking plate (1, Fig. 148) is assembled
valve housing (9, Fig. 149). ,
with the tab facing towards the transmission control
valve housing and against the milled fiat (2) on the
variable orifice assembly. Install valve spool (5), spring (4), and stop (3).

Install the spacer (6, Fig. 144). Install plug (1) with new O-ring (2).

With the assembly still held in the above position

and without having moved the valve in the housing
from the 0.400 inch (10.16 mm) dimension, install the
stop (4, Fig. 146) with its long straight side facing right
and in a vertical position. The ears on the stop should
point toward the valve.

Install the splined variable orifice lever (3) so the

lever is also in a vertical position parallel with the long
straight side of the stop.

install the override lever spring (11, Fig. 144) on the

override lever spacer (10). Install the override lever (9)
on the narrow stepped end of the spacer.

Install the override lever assembly to the valve so

the override lever is directly over the variable orifice
lever. Tighten the lock nut (12).

If the variable orifice valve had been moved in the

housing during tightening of the lock nut, reset the
variable orifice valve slot in the housing window to the
0.400 inch (10.16 mm) dimension as described above.
Then, with the automatic control valve lever facing in
the straight vertical up position, install the variable
orifice assembly into the transmission control valve
housing and install and tighten retainer cap screws.

Install and tighten the cap screw for the tabbed side
of the locking plate first.
l--Plug (2 used) 5-Valve Spool (2 used)
After the transmission control valve is installed in the 2-O-Ring (2 used) 6-Valve Sleeve (2 used)
unit, refer to procedures 4, 8, and 9, adjustment sec- !&stop (2 used) 7-Spring Pin (2 used)
tion, Group 9026, for adjustment and installation pro- 4-Spring (2 used) &Spring Pin Bore
cedures. 94nstall Spring Pin
With Slit This Way

Fig. 749~Steering Valve hstallation

Litho in U.S.A.
 JD750 Crawler Bulldozer Transmission 3
. TM-1 136 (Feb-77) Transmission Hydraulics 0360-79

l-Link 5-O-Ring E-Spacer

2-Spring Pin 6-O-Ring g-Control Shaft Handle (2 used)
3-Steering Lever ‘I-Steering Valve Lever Housing lo--Nut (2 used)
4-Steering Control Shaft

Fig. 150~Sieering Valve Lever Components

Steering Valve Lever Assembly

Install steering lever (3, Fig. 150) on steering control
shaft (4).

Install spring pin (2).

Install new O-ring (5) on control shaft (4) and new

O-ring (6) on steering valve lever housing (7).

Install control shaft in lever housing.

Install control shaft handle (1, Fig. 151) on control

shaft (4) so that the handle is in the closest vertical
position parallel to the steering lever (3) and pointing in
the opposite direction (See Fig. 151).

Install steering lever assembly with new O-ring (6,

Fig. 150) into housing. As you install the lever assem-
bly, also install link (1) to the steering lever (3) and
valve spool.

(T4518ON
Install cap screws and tighten.
l-Control Shaft Handle 3-Steering Lever
P-Steering Valve Lever 4-Steering Control Shaft
Housing

Fig, 751~Control Handle Alignment

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-80 Transmission Hydraulics TM- 1136 (Feb-77)

Speed Control Valve Install shims so that there is a 0.005 to 0.015 inch
(0.13 to 0.25 mm) opening (2) between the center of
Install speed control plunger (4, Fig. 152) into speed
the valve spool and the P3 test port bore (1).
control sleeve (3).
Use a wire feeler gauge to measure this distance
Install assembly into valve housing using Special
through the P3 test port bore.
Tool JD325 (2) and tighten to 10 lb-ft (14 Nm) (1 kg/m)
torque.

Install plug with new O-ring (1).

T48578N

l-P3 Test Port Bore &Speed Control Sleeve

24.005-0.010 Inch Opening O-Speed Control Plunger
(0.13 to 0.25 mm) 7-Transmission Control
3-Valve Spool Valve Housing
4-Speed Control Spring &Speed Control Cam

Fig. 153~Speed Control Valve Shim Installation

Install speed control adjusting spring, (7, Fig. 154)

and valve seat (6).

Install plunger (4) with new O-ring (5).

l-Plug with O-Ring 3-Speed Control Sleeve

Install adjustment screw assembly (1) in plug (2) and
2-Special Tool JD325 4-Speed Control Plunger
install assembly in the valve housing.
Fig. 152~Speed Control Sleeve /nstal/ation

Install speed control spring (10, Fig. 154).

Install shim or shims (9) on P3 speed control spool

(8) and install. into housing.

NOTE: If new sleeve (3, Fig. 152), plunger (4) or

spring (10, Fig. 154 are installed, the following pro-
cedure must be used to determine shim pack thick-
ness.

Install the speed control plunger (6, Fig. 153) and

sleeve (5). Install the speed control spring (4) and
valve spool (3). Insure that the spring and spool are
seated against the speed control plunger.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-l 136 (Nov-78) Transmission Hydraulics 0360-81

FNR Valve

l-Nut l8-Spring Pin (FNR

P-FNR Control Shah Handle Valve Lever)
3-Control Stop 1 l-O-Ring
l-Adjustment Screw 7-Speed Control 4-Spacer 12-Control Shaft
Assembly Adjusting Spring j-Bushing 13-FNR Valve Link
2-Special Plug 8-P3 Speed Control Spool 8-O-Ring 14-FNR Valve Lever
3-O-Ring g--Shim (Use as Required) 7-Plug 18-Speed Control Cam
4-Plunger 18-Speed Control Spring 8-O-Ring 18-FNR Valve
5-O-Ring g-Spring Pin (Speed 17-O-Ring
GValve Seat Control Cam) 18-FNR Valve Bore Plug

Fig. 154~Speed Control Valve Installation Fig. 755~FNR Valve Installation

After the transmission control valve is installed in the Slide control shaft (12, Fig. 155) into transmission
unit, refer to procedure 10, adjustment section, Group control valve housing with new O-ring (11).
9026, for valve adjustment.
Install FNR valve lever (14) and speed control cam
(15) on control shaft.

Install spring pin (9) in speed control cam

Install FNR valve (16) and plug (18) with new O-ring
(17).

Litho in U.S.A.
 3 Transmission JD756 Crawler Bulldozer
0360-82 Transmission Hydraulics TM-1 136 (NOW78)

Install link (13, Fig. 155) between FNR valve lever Port Plate and Cover Assembly
(14) and FNR valve (16).
Place new gasket (2, Fig. 157) on valve housing (3).

NOTE: If new link is used, be sure that the part

Install port plate (1).
number is the same as the removed link. The replace-
ment kit for this link contains three sizes of the link.
Place new gasket (4) on port plate (1) and install
Each is stamped with a vendor number.
control valve cover (5).

Install spring pin (10) in FNR valve lever driving it

NOTE: The control valve cover is different between
flush with the lever.
the transmission control valve for units equipped with a
cab and units not equipped with a cab. The cover for
NOTE: Use only the specified spring pin when as-
units with a cab is mounted with the hydraulic line ports
sembling FNR valve lever to control shaft. If a longer
towards the front of the valve; the cover for units
spring pin is used, disassembly will be difficult.
without a cab is mounted with the ports toward the rear.

Install bushing (5) with new O-ring (6).

Install cap screws (6) and tighten.

wl
i
1 Install spacer (4, Fig. 155).

Install the control stop (3) so that when the speed

control cam (4, Fig. 156) is held in its neutral detent
position (6) by the speed control plunger (5), the con-
trol stops (3) long straight side is facing the front of the
control valve and is in the most vertical position parallel
to the speed control cam (4). The ears of the stop must
point toward the valve housing.

Install FNR control shaft handle (1, Fig. 156) so that

it is parallel to the control stop (3).

Install and tighten nut (1, Fig. 155).

After transmission control valve is installed in the

unit, refer to procedure 12, adjustment section, Group
9026, for valve adjustment.

I T58226A'

l-FNR Control Shaft 4-Speed Control Cam

Handle G-Speed Control Plunger
2-Control Shaft GNeutral Detent Position
3-Control Stop

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-l 736 (Nov-75) Transmission Hydraulics 0360-83

1-Port Plate 3-Control Valve Housing 5-Control Valve Cover

P-Valve Housing Gasket 4-Cover Gasket 6-Cap Screw (20 used)

Fig. 157-Port Plate and Cover Assembly

Litho in U.S.A.
 3 Transmission JD 750 Crawler Bulldozer
0360-84 Transmission Hydraulics TM-1 136 (Nov-75)

INSTALLATION Procedure 6 - Pl over pressure relief valve

pressure adjustment
Place transmission control valve in unit and tighten
cap screws.
Procedure 7 - P2 pressure regulator pressure
adjustment
Connect the automatic control valve shutoff valve
linkage.
Procedure 8 - Automatic control valve variable
orifice installation adjustment
Connect all control valve lines.

Procedure 9 - Automatic control valve variable

Install cross shaft assembly and tighten all cap
orifice pressure adjustment
screws.

Procedure 10 - P3 speed control valve pressure ,

Refer to the adjustment section, Group 9026, for the
adjustment
following procedures for adjusting the linkage for the
control valve. Do these procedures in the order they
Procedure 11 - Transmission automatic control
are listed.
valve P4 pressure adjustment

•l Procedure 3 - FRN speed control

neutral adjustment
lever linkage
Procedure 12 - Transmission
ment
full speed adjust-

Procedure 4 - Engine speed and transmission

Procedure 13 - Bleeding of transmission control
control valve synchronization.
circuit

Procedure 5 - Transmission fluid heat up proce-

Procedure 14 - Steering valve stop adjustment on
dure
the transmission control valve

NOTE: The unit must now be blocked so that the

Procedure 15 - Steering linkage adjustment
tracks are off the ground and the brake pedal is locked
down.
Procedure 16 - Steering neutral stop adjustment

Procedure 17 - Return-to-neutral cable adjust-

ment

Procedure 18 - Transmission automatic control

valve shutoff cable adjustment

Replace floor boards in unit.

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JD 750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Transmission Hydraulics 0360-85

OIL c OOLER
GENERAL INFORMATION INSPECTION
The oil cooler is an oil to air type cooler mounted Check for leakage and for clogged or bent fins.
vertically beside the radiator in the front of the ma-
chine. Repair as necessary.

INSTALLATION
Assemble the oil cooler to radiator.

Install the ra ‘ator-oil cooler assembly per Group

T
0510.

l-Oil Cooler 3-Air Conditioner

2-Cooler Inlet Hose Condenser
4-Radiator

Fig. 158-Oil Cooler

REMOVAL
Remove the radiator-oil cooler assembly per Group
0510.

Remove the oil cooler from the radiator.

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-86 Transmission Hydraulics TM-1 136 (Nov-78)

OIL COOLER BYPASS VALVE

T61787N

l-Plug (2 used) 4-Thermostatic Bypass Assembly ‘I-Steel Ball (4 used)

2--O-Fling (2 used) (After Ser. No. 283325) 8-Pressure Spring
3-Spring 6-Valve Spool g--Thermostatic Bypass Assembly
6-Valve Housing (Prior to Ser. No. 283326)

Fig. 159-Oil Cooler Bypass Valve (Exploded View)

GENERAL INFORMATION ASSEMBLY

An external bypass valve is used as a means of Clean all parts in diesel fuel and blow dry with
quickly warming up the transmission oil. It allows the oil compressed air.
to bypass the oil cooler and circulate between the
transmissions and reservoir. The oil cooler bypass is Coat all parts with hydrostatic fluid prior to assembly.
located on the right side main frame of the unit.
Install valve spool (5, Fig. 159) and pressure spring
REMOVAL (3). fnstall plug (1) with new O-ring (2).
Disconnect and cap all lines and fittings.
INSTALLATION
Remove two cap screws and remove valve from Install in unit and tighten two cap screws.
unit.
Connect the oil cooler bypass valve lines.
DISASSEMBLY
Remove plugs (1, Fig. 159).

Remove spring (3) and thermostatic bypass as-

sembly (4).

Remove pressure spring (8) and valve spool (5).

INSPECTION
Inspect parts for wear and scoring.

Replace parts as necessary.

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-75) Transmission Hydraulics 0360-87

TRANSMISSION OPERATING DISASSEMBLY

PRESSURE VALVE

l-Left Transmission Pump End Cap

2-Transmission Operating Pressure Valve
3-Operating Pressure Crossover Hose
T43356
Fig. 160-Transmission Operating Pressure Valve
l-Connector 6-Connector
P-O-Ring ?-O-Ring
GENERAL INFORMATION 8-Valve Spool
3-Washer (2 used)
The transmission operating pressure valve monitors 4-Spring (2 used) g-Elbow
CValve Housing
the charge pressures of both transmissions. The lower
of the two charge pressures is routed to the transmis- Fig. 16 1-Operating Pressure Valve (Exploded View)
sion oil pressure gauge on the dash.
Remove connector (1, Fig. 161) and elbow (9).
REMOVAL
The operating pressure valve may be removed Remove washers (3), springs (4), and valve spool
without removing the transmissions through the access 03).
hole in the rear of the crawler.
!NSPECTION
Disconnect the operating pressure crossover hose Clean all parts in diesel fuel.
(3, Fig. 160) and cap the hose and fitting.
Inspect parts for wear and scoring. Replace as
Disconnect the operating pressure valve (2) from the necessary.
left transmission pump end cap (1) and cap the fittings.
Prior to assembly coat all parts in hydrostatic fluid.

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 3 Transmission JD750 Crawler Bulldozer
0360-88 Transmission Hydraulics TM-l 136 (Nov-75)

ASSEMBLY INSTALLATION
install spool (8, Fig. 161), springs (4) and washers Connect elbow (9) in operating pressure valve to
(3) in valve housing. fitting in left transmission pump end cap.

Install connector (1) and elbow (9) with new O-rings Connect the operating pressure crossover hose.
(2).

‘,

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JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Apr- 79) Transmission Hydraulics 0360-89

TRANSMISSION INSPECTION
RESERVOIR Inspect sump for leaks.

GENERAL INFORMATION Thoroughly clean sump with diesel fuel.

A 26-gallon (99.4 L) sealed reservoir for hydrostatic

INSTALLATION
fluid is located on the right rear fender of the crawler.
During operation the reservoir becomes pressurized Place sump on unit and install cap screws.
up to 6 psi (0.4 bar) (0.4 kg/cm2).
Connect sump lines.
REMOVAL
Fill sump with clean hydrostatic fluid, of the recom-
Remove cap screws and rotate cab or canopy for-
mended type. See Section I, Group V.
ward.
Install right hand rear fenders.
Remove back access cover under fuel tank.
Install fuel tank and connect fuel lines.
Disconnect and cap fuel lines.
Install back access cover under fuel tank.
Remove fuel tank.
Rotate cab or canopy into position.
Remove right hand rear fender.
Prior to starting the engine, refer to start-up pro-
Drain hydrostatic reservoir. cedure in the transmission installation section, this
group.
Disconnect reservoir hoses.

Remove cap screws and remove hydrostatic sump.

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3 Transmission JD750 Crawler Bulldozer
0360-90 Transmission Hydraulics TM- 1136 (Apr-79)

TRANSMISSION
FILTER

GENERAL INFORMATION
Two IO-micron dual-stage suction side filters are
located at the top of the transmission reservoir behind
a lockable panel.

T66052N

l-Filter Base Gasket 9-Special Washer

( -313241) ( -313241) (2 used)
2-Lock Washer (8 used) l&-Cap Screw (8 used)
( -313241) ( -313241)
3-Adapter (2 used) ll-Washer (2 used)
4-Filter Base ( -313241)
CVacuum Switch 12-Hydrostatic Sump
(2 used) U-O-Ring
8-O-Ring (2 used) U-Filler plug
‘I--Spin-on Filter ( -318848)
(2 used) Vacuum Relief Valve
8=-Gap Screw (2 used) (318849- )
( -313241)
l-Transmission Filter 3-Transmission Reservoir Fig. 163-Transmission Filters (Exploded Wew)
P-Filter Base
Install new gasket (1, Fig. 163) and install adapters
Fig. 162-Transmission Filter (3).
install filter base (4). Seal screw threads with JD
REMOVAL Loctite Hydraulic Sealant and Thread Lock, T43513, or
Remove spin-on filter (7, Fig. 163) with O-rings (6). an equivalent. Install special sealing washers (9) and
washers (11) to cap screws (8). Install lock washers (2)
Remove adapters (3). to cap screws (10). Install all cap screws and torque to
NOTE: On units (3 13242- ) the filter base (4) 30 lb-ft (41 Nm) (4 kg-m) per sequence pattern in Fig.
is welded to the hydrostatic sump (12). Cap screws (8 164.
and lo), washers (2, 9, and 1 I), and filter base gasket Bleed the transmission control circuit as outlined in
(1) are not used. Procedure 13, Group 9026.

Remove cap screws (8 and 10).

Remove filter base (4).

INSPECTION
Inspect areas for leakage.

Replace all O-rings. T48580N

Replace spin-on filters as necessary. Fig. 164-Torque Sequence Pattern
for Filter Base Attaching Screws

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JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Apr-79) Transmission Hydraulics 0360-91

VACUUM RELIEF VALVE (318549- )

l-O-Ring 4-Cheek Valve

2-Vacuum Plug 5-Filter
3-Adapter 6-Cap

Fig. 165-Vacuum Relief Valve

To service the filter in the vacuum relief valve,

remove the cap (6, Fig. 165) from the check valve (4).

Apply John Deere Medium Strength Loctite or an

equivalent to pipe thread end of adapter (3) if the
assembly has been completely disassembled.

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0360-92 Transmission Hydraulics TM- 1136 (Apr- 79)

Litho in U.S.A.
JD7W Crawler Bulldozer Transmission 3
TM-l 136 (Nov-78) Clutch Disconnect and Controls 0370-l

Group 0370
CLUTCH DISCONNECT AND CONTROLS
CONTROLS
GENERAL IbjFORMATlON REPAIR
The engine disconnect clutch allows the engine to Inspect the clutch disconnect linkage components
be disengaged from the splitter drive assembly for cold (Figs. 1 and 2) for bent or worn condition.
weather engine starting.
Check pivot points and headed pins for excessive
As the clutch control lever is pulled upward, the wear.
clutch cable actuates the control linkage rotating the
clutch fork shaft. This forces the release bearing for- Inspect cable for bent or worn condition. Check
ward against the pressure plate release levers. The cable to see that it operates freely.
clutch release levers retract the clutch pressure plate,
releasing the driven disk from the pressure plate and Replace worn or damaged parts as needed.
driving surface of the flywheel, thus disconnecting the
engine from the splitter drive assembly. INSTALLATION
If clutch shaft was removed from clutch housing,
IMPORTANT: Instruct the operator to engage
install clutch shaft and index lever horizontal towards
the engine disconnect clutch slowly after the en-
the front.
gine has started and warmed up.
Install parts using Figs. 1 and 2 as guides.
REMOVAL
Disassemble clutch control linkage using Figs. 1 and Adjust disconnect clutch linkage so that approxi-
2 as guides. mately 2 inches (51 mm) of control lever travel is
required to bring throwout bearing in contact with
clutch release levers. Refer to Group 9020. \

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0370-2 Clutch Disconnect and Controls TM- I 136 (Nov- 78)

-- --y

5- 8 -23
r-- * -7
6 00

n/g ”

%--IO
R
‘11
3

11441308

l-Spring Pin 7-Bell Crank 13-Control Cable

2-Lever &-Spring Pin M-Pivot
Z--Cotter Pin g--Cotter Pin (4 used) l&i-Pivot Pin
4-4od W-Pin (4 used) W-Cap Screw
&-Hand Grip 11-Adjustable End Yoke (3 used) 17-&N Crank
C-Shaft 12-Grommet W-End Rod

Fig. l-Clutch @xonnect Linkage (With Cab)

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-78) Clutch Disconnect and Controls 0370-3

t/7
PNY8
g\ OJ
& 0

14’
&O
0 iv8

15’ Q 92

T44131N

1-Lever S-Spring Pin 11-Pivot

2-Gap Screw (2 used) 7-Cotter Pin (4 used) 12-Pivot Pin
3-Washer (2 used) S-Pin (4 used) 13-Gap Screw
4-Lever Stop g-Adjustable End Yoke (3 used) Cl-Bell Crank
5-Bell Crank lO-Control Cabk 15-End FM

Fig. PClutch Disconnect Linkage (Without Cab)

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0370-4 Clutch Disconnect and Controls TM-l 136 (Nov-78)

CLUTCH ELEMENTS
GENERAL INFORMATION
The engine disconnect clutch allows the engine to
be disconnected from the splitter drive for cold weather
starting.

The engine disconnect clutch is a simple dry-disk

assembly mounted on the engine flywheel. The clutch
disk is held in engagement by clutch springs.

When the disconnect clutch is engaged, engine

power is transmitted from the engine crankshaft to the
transmission via the splitter drive.

IMPORTANT: Instruct the operator to engage

the engine disconnect clutch slowly after the en-
gine has started and warmed up.

REMOVAL
Refer to Section 4, Group 0400 and remove the
engine.
l-Driven Disk 3-Pressure Plate
2-Flywheel 4-Gap Screws (6 used)

Fig. 3-Disconnect Clutch Elements

REPAIR
Remove cap screws (4, Fig. 3) to remove pressure
plate (3) and driven disk (1) from engine flywheel (2).

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JD7!50 Crawler Bulldozer Transmission 3
TM-l 136 (Nov-78) Clutch Disconnect and Controls 0370-5

Assembly
Press bushings (19, Fig. 5) in clutch housing flush
with bore.

Use an old input shaft or a clutch aligning tool (JDE

52) when installing driven disk (12) and pressure plate
(11).

Install driven disk with long hub away from flywheel.

Align driven disk with input shaft bearing when in-

stalling pressure plate.

Install pressure plate-to-flywheel cap screws (10).

NOTE: The clutch pressure plate release levers are

factory set, and no further adjustment should be made.

Assemble clutch housing to splitter housing.

l-Clutch Shaft Clutch Fork Shaft
2-Coupling Clutch Fork
3-Gap Screws (3 used) ‘I-Input Shaft Coat splines in coupling (2, Fig. 4) with John Deere
4-Clutch Fork g--Release Bearing Never-Seez or equivalent.
support g-Spring Pin (2 used)
Install clutch fork assembly in clutch housing and
Fig. 4-Disconnect Clutch Assembly
clip (22, Fig. 5) to splitter housing.

Disconnect spring (15, Fig. 5) from bearing carrier

Clutch shaft (21) should operate freely after assem-
(14) and pump cover.
bly.

Remove bearing carrier (14) and release bearing

Install release bearing (13), with largest outside
from pump cover. Remove release bearing (13) from
diameter facing flywheel, on clutch release bearing
bearing carrier.
carrier (14). Rotate bearing while assembling to carrier.
Pack bearing and cavity in release bearing carrier with
Remove clip (22) from splitter housing and pull
high temperature grease.
clutch shaft (21) from clutch housing.

Install release bearing carrier (14, Fig. 5) and spring

Remove cap screws (3, Fig. 4) and remove clutch
(5).
fork assembly.

Lever on clutch shaft (21) should be in horizontal

Remove coupling (2) from clutch fork shaft (5).
position towards the front of crawler when the release
bearing is against the clutch release levers.
If clutch fork shaft (5), clutch fork (6) or clutch fork
support need servicing, drive spring pins (9) out of
clutch fork.

To remove clutch housing (20, Fig. 5) from splitter

housing, remove cap screws (18). Pull clutch housing
from splitter housing.

Inspects parts for cracks, wear or other damage. ,

Replace parts as necessary.

Litho in U.S.A.
3 Transmission JD750 ‘Crawler Bulldozer
0390-6 Clutch Disconnect and Controls TM-l 136 (Nov-78)

r
6

T63064F
33

l-Cap Screw (2 used) 1 l-Pressure Plate 26-Clutch Housing

2-Lock Washer (15 used) 12-Driven Disk 21-Clutch Shag
3-Washer (2 used) 13-Release Bearing 22-Clip
4-Clutch Fork Support M-Clutch Release 23-Cap Screw /(4 used)

‘I
6-Lock Washer (7 used) Bearing Carrier 24-Special Washer (4 used)
6-Cap Screw (3 used) 16-Spring 26-Clutch Housing Support (2 used)
7-Clutch Fork Shaft IGCoupling 26-Cap Screw (7 used)
&Clutch Fork 17-Retaining Ring 27-Clip
g-Spring Pin (2 used) l&Cap Screw (4 used) l&Washer
16-Special Screw (6 used) 16--Bushing (2 used) 24-Cap Screw

Fig. 3-Clutch Housing and Engine Disconnect

INSTALLATION
Apply John Deere Loctite Plastic gasket or equiva-
lent to front and rear finished surfaces of clutch hous-
ing.

Join clutch housing and splitter housing to engine.

Refer to Section 4, Group 0400 and install engine,

clutch housing and splitter housing in crawler as a unit.

Connect drive shafts to drive hubs.

Litho in U.S.A.
JD 750 Crawler Bulldozer Transmission 3
TM- 1136 (Feb-77) Specifications and Special Tools 0399-l

Group 0399
SPECIFICATIONS AND SPECIAL TOOLS
INPUT DRIVE SHAFTS AND U-JOINTS i
SPECIFICATIONS AND TORQUE VALUES
1 - Tighten driven hub to transmission
input shaft lock nut to. . . . . . . . . . . . . . 300 lb-ft
(407 Nm) (41 kg/m)
2 - Tighten U-bolts to . . . . . , . . . . . . . . . . . . . 22 lb-ft
(30 Nm) (3 kg/m)

11485748
Fig. l-Driven Hub

TRANSMISSION HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES

T45219N

Fig. lA-Transmission Pump Assembly I

Maximum difference between 5- Pump shaft end play. . ...

0.006 - 0.016 in.
trunnion shim packs . . . . _. . . . . . . . .0.008 in. (0.152 - 0.406 mm)
(0.203 mm) Pump shaft rotate force . . . . . . . . . .7 - 11 lb-ft
Swashplate preload . . . . . . 0.002 - 0.004 in. (9 - 15 Nm) (1 - 2 kg/m)
(0.051 - 0.102 mm) 6 - Pump to motor cap screw torque 170 - 187 lb-ft
Swashplate drag . . . . . ; . . . . . . . 3 - 5 lb. (230 - 254 Nm) (24 - 26 kg/m)
(114.--23N)(l -2kg) 7 - Check valve torque . . . . . . . . . . . .30 - 40 lb-ft
3 - Front cover cap screw torque. . . .35 - 39 lb-ft (41 - 54 Nm) (4 - 6 kg/m)
(47 - 53 Nm) (4.8 - 5.4 kg/m) 8 - End cap cap screw torque , . . . . .35 - 39 lb-ft
4 - Yoke nut torque.. . . . . , . . . . . _. . 300 lb-ft (47 - 53 Nm) (4.8 - 5.4 kg/m)
(407 Nm) (41 kg/m)

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0399-2 Specifications and Special Tools TM- 1136 (Feb-77)

TRANSMISSION HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES-Continued

Traryission-Continued

\
\ M-\
\-NH’ ‘\
3
4 ,/’
o@

Fig. P-Transmission Motor Assembly

1 - End cap cap screw torque . . . 170 - 185 lb-ft 4 - Motor shaft end play. _. . . . . . . 0.006 - 0.016 in.
(230 - 251 Nm) (24 - 26 kg/m) (0.152 - 0.406 mm)
2- Maximum difference between Motor shaft rotate force . . . . . . .26 - 38.50 lb-ft
trunnion shim packs . . . . . . . . . . .0.008 in. (35 - 52 Nm) (4 - 5 kg/m)
(0.203 mm) 5 - Front cover cap screw torque. . . .85 - 93 lb-ft
3 - Swashplate preload. . . . . 0.002 - 0.004 in. (115 - 126 Nm) (12 - 13 kg/m)
(0.051 - 0.102 mm)
Swashplate drag . . . . .3.50 - 6.50 lb.
(16 - 29 N) (2 - 3 kg)

Litho in U.S.A.
JD 750 Crawler Bulldozer Transmission 3
TM- 1136 (Nov-75) Specifications and Special Tools 0399-3

TRANSMISSION HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES-Continued

Transmission-Continued

T4522lN

fig. 3-Cylinder Block Assembly

1 - Motor cylinder block spring 2 - Motor retainer spring

Free length . . . 1.82 in. Free length . . . . .3.11 in.
(46.2 mm) (79 mm)
Test length . . . . .. . . . 1.18 in. Test length . . . . . . .2.63 in.
(30 mm) (67 mm)
when compressed with 293 -c 7.5 lb. when compressed with 77.5 r 7 lb.
(1 304 t 33 N) (133 t 3 kg) (345 I 31 N) (35 i 3 kg)
Pump cylinder block spring Pump retainer spring
Free length.. . .. . . . . 1.33 in. Free length . . . . .. . . .2.31 in.
(33.8 mm) (59 mm)
Test length . . .. . .0.89 in. Test length . . . . . . . . . .2.08 in.
(22.6 mm) (53 mm)
when compressed with 177 + 4 lb. when compressed with 41 -c 3 lb.
(788 2 18 N) (80 i 2 kg) (182 & 13 N) (19 r 1 kg)

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0399-4 SDecifications and SDecial Tools TM- 1136 (Nov-75)

TRANSMISSION HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES-Continued

Transmission-Continued

1 - Spool arm cap screw . . . . . . . . 30 - 36 lb-in

(3.4 - 4.1 Nm) (0.35 - 0.41 kg/m)
2 - Sleeve set screw . . . . . . . 25 - 30 lb-in
(2.8 - 3.4 Nm) (0.29 - 0.35 kg/m)
3 - Mounting cap screw ... .. .. . 10 - 11 lb-ft
(14 to 15 Nm) (1 - 2 kg/m)

T45222N

Fig. 4-Pump and Motor Displacement Control Valve

1 - High pressure relief valve setting. . . .

6100 to 6400 psi
(421 bar) (429 kg/cm*)
;l@.&U3-0-@@
High pressure relief valve
torque.. . . . . . . . . . . . . .20 - 30 lb-ft
(27 - 41 Nm) (3 - 4 kg/m)
2 - Charge pressure relief valve setting . ..
200 to 240 psi
(14 to 17 bar) (14 to 17 kg/cm*)
3 - Mounting cap screw torque. . . .20 - 22 lb-ft
(27 - 30 Nm) (2.8 to 3.0 kg/m)

T45223N &I
Fig. 5Manifold Valve Assembly

Litho in U.S.A.
JD 750 Crawler Bulldozer Transmission 3
TM-l 136 (Nov-75) Specifications and Special Tools 0399-5

TRANSMISSION HYDRAULICS
SPECIFICATIONS AND TORQUE VAL.UES-Continued

Transmission-Continued

Mounting cap screw torque. .10 - 11 lb-ft

(14 - 15 Nm) (1 - 2 kg/m)
Connector torque .17 - 19 lb-ft
(23 - 26 Nm) (2 - 3 kg/m)
Charge relief valve spring
Free length .2.82 in.
(71.6 mm)
Test length .2.41 in.
(61.2 mm)
when compressed with 26.6 t_ 2.7 lb.
(118 212 N) (12 i 1 kg)
4 - Neutral charge relief
T45224N valve setting 260 to 340 psi
Fig. g-Charge Pump Assembly (18 to 24 bar) (18 to 24 kg/cm)

T45225N

Fig. 7-Transmission Bypass Valve

1 - Valve spring (inner)

Free length .. ,
.4.14 in.
(105 mm)
Test length . . 1.50 in.
(38 mm)
when compressed with 62 t 6 lb.
(276 c 27 N) (28 i- 3 kg)
2 - Valve spring (outer)
Free length . . .3.69 in.
(94 mm)
Test length . 1.60 in.
(41 mm)
when compressed with 94 t 9 lb.
(418 t 40 N) (43 + 4 kg)

Litho in U.S.A.
 ..~ JD750 Crawler Bulldozer
3 Transmission
0399-6 Specifications and S,oecial Tools TM- 1136 (Nov-75)

TRANSMISSION HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES-Continued

Transmission Operating Pressure Valve

1 - Valve spool spring
Free length 1.14 in.
(29 mm)
Test length . .I in.
(25 mm)
when compressed with 2.2 i- 0.4 lb.
(10 jl 2 N) (1 2 0.2 kg)

T45226N

Fig. B-Operating Pressure Valve Springs

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1736 (Nov-75) Specifications and Special Tools 0399-7

TRANSMISSION HYDRAULICS
SPECIFICATIONS AND SPECIAL TOOLS-Continued

Transmission Control Valve

1 - P2 Pressure regulator
pressure setting 180 t 20 psi
(12 2 1 bar) (13 +- 1 kg/cm’)
at 2100 t 5 rpm at 140 to 160°F
(60 to 71°C)
2 - Pl over pressure relief valve
pressure setting 310 z 30 psi
(21 ? 2 bar) (22 ? 2 kg/cm’)
at 2100 + 5 rpm at 140 to 160°F
(60 to 71°C)

T45227N

Fig. 9-Transmission Control Valve

Pi and P2 Valves

1 - Steering valve spring

Free length 2.1 in.
(53 mm)
Test length 1.7 in.
(43 mm)
when compressed with 4.4 f 0.5 lb.
(20 + 2 N) (2 T 0.2 kg)

T45228N 1

Fig. 1O-Transmission Control Valve Steering Valve

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0399-8 Specifications and Special Tools TM- 1136 ~Nov-75)

TRANSMISSION HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES-Continued

Transmission Control Valve-Continued

T45229N

Fig. 1 t-Transmission Control Valve Speed Control Valve

1 - Speed control sleeve torque 10 lb-ft 3 - Speed control valve spool

(14 Nm) (1 kg/m) clearance. . 0.005 - 0.015 in.
2 - Speed control spring (0.13 - 0.38 mm)
Free length,. . 1.85 in.
(47 mm) 4 - Speed control adjusting spring
Test length . . . . 1.62 in. Free length.. .0.80 in.
(41 mm) (20 mm)
when compressed with 27.5 i 4 lb. Test length . .0.56 in.
(122 zz 18 N) (12 c 2 kg) (14 mm)
when compressed with 5.4 r 0.5 lb.
(24 ‘I 2 N) (2 +- 0.2 kg)

Litho in U.S.A.
XI750 Crawler Bulldozer Transmission 3
TM-1 736 (Nov-78) Specifications and Special Tools 0399-g

TRANSMISSION HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES-Continued

Transmission Control Valve-Continued

T45230N

Fig. 7%Transmission Control Valve Automatic Control Valve

1 - Accumulator spring 2 - Automatic control valve spring

Free length . . ..... .
. . . . . . 2.5 in. Free length . ... . . . .1.13 in.
(63.5 mm) (29 mm)
Test length . . . . . . . . . . . .2.03 in. Test length . . .. . .0.976 in.
(52 mm) (25 mm)
when compressed with 123 F 12 lb. when compressed with 34.7 c 3 lb.
(547 k 53 N) (56 + 5 kg) (154 + 13 N) (16 + 1 kg)

Oil Cooler Bypass Valve

T45231N
fig, 73-Oil Cooler Bypass Valve Springs

1 - Thermostatic spring 2 - Spring .

Free length . _ . ... . ..
. . . . . .2 in. \ ,,./“Free length .L.~. . . . . 3.5 in.
(51 mm) l- (89 mm)
Test length . ..... . . . . . . . 1.38 in. Test length . .... . . . . .2.06 in.
(35 mm) ‘\ (52 mm)
when compressed with 20 2 2 lb. when compressed with 17 lb.
(89 t 9 N) (9 f 0.9 kg) (76 N) (8 kg)

Lifho in U.S.A.
 3 Transmission JD750 Crawler Bulldozer
0399-l 0 Specifications and Special Tools TM- 1136 (Nov-78)

/ CLUTCH DISCONNECT AND CONTROLS

SPECJFICATIONS AN,D TORQUE VALUES

1 - Clutch control lever

free travel.. . . . . .. . . _. . . . . . .2 inches
- (51 mm)
1
f

P48495N

Fig. 14-Clutch Control Lever

CLUTCH ELEMENTS
SPECIFICATIONS AND TORQUE VALUES

1 - Press bushings flush with bore in clutch housing.

P43685~

Fig. IdClutch Housing Bushings

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JD 750 Crawler Bulldozer Transmission 3
TM-1 136 (Nov-78) Specifications and Special Tools 0399-11

TRANSMISSION HYDRAULICS
SPECIAL TOOLS

Essential Tools

Tool Tool Number Use

JD-317 To prevent damage to both the

shaft and bearing when installing
the rear input bearing.

Fig. 16-Hydrosfafic Pump Rear searing

lnslallafion Tool

JD-321 To install the input shaft seal on the

transmission pump.

Fig. 17-Hydrostatic Pump input Shaft Seal

/nsfa//aiion Tool

JD-323 To remove the rear bearing from

the hydrostatic pump without
damaging the lapped surfaces on
the pump.

fig. Id-Hydrostatic Pump Rear Searing Puller

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3 Transmission JD750 Crawler Bulldozer
0399-l 2 Specifications and Special Tools TM-l 136 (Nov-78)

TRANSMISSION HYDRAULICS
SPECIAL TOOLS-Continued

Essential Tools-Continued

Tool Tool Number Use

JD-332 To properly torque the cap screws

which are used to mount the hy-
drostatic pump to the motor.

5’
T45240N

,;
I Fig. 194iydrostatic Pump and Motor Torque
Wrench Adapter

JD-318 To prevent damage to both the

shaft and bearing when installing
the rear output bearing.

Fig. ZO-Hydrostatic Motor Rear Bearing

Installation Tool

JD-320 To install the output shaft seal on

the transmission motor.

Fig. PI-Hydrostatic Motor Output Shafi

Seal installation Tool

Litho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM-l 136 (Nov-78) Specifications and Special Tools 0399-I 3

TRANSMISSION HYDRAULICS
SPECIAL TOOL ,S-Continued

Essential Tools-Continued

Tool Number Use

JD-322 To remove the rear bearing from

the hydrostatic motor without
damaging the lapped surfaces on
the motor.

Fig. 22-Hydrostatic Motor Rear Bearing Pulkr

JD-326 To align the motor’s female spline

to the input shaft of the final
drive.

T45241N

Fig. ,ZHiydrostatic Motor Spline

Akgnmenf Tool

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 3 Transmission JO750 Crawler Bulldozer
0399-14 Specifications and Special Tools TM-1 136 (Nov-78)

TRANSMISSION HYDRAULICS
SPECIAL TOOLS-Continued

Essential Tools-Continued

Tool Number Use

JD-325 To remove and install speed control

valve sleeve in the transmission
control valve.

PI T45234N

Fb. 24-Hydrosiafic Speed Control

Valve Sleeve Removal Tool

bitho in U.S.A.
JD750 Crawler Bulldozer Transmission 3
TM- 1136 (Apr- 79) Specifications and Special Tools 0399-15

TRANSMISSION HYDRAULICS
SPECIAL TOOLS-Continued

Convenience Tools

Tool Tool Number Use

JD-328 ?o provide stable support for the

hydrostatic transmission pump
when the pump is removed from
the transmission assembly.

Fig. 25-Hydrostatic Pump Bench Stand

JD-327 To provide stable support for the

hydrostatic transmission when out-
of-chassis service is required.

Fig. 26-Hydrostatic Motor Floor Stand JDG-37 Servo sleeve special socket set. 1

Litho in U.S.A.
3 Transmission JD750 Crawler Bulldozer
0399-16 Specifications and Special Tools TM- 1136 (Apr- 79)

CLUTCH DISCONNECT AND CONTROLS

SPECIAL TOOLS

Essential Tools
Tool Tool No. Use

JDE-52 Used to properly line up clutch

disk.

Fig. 274Jnivet’sal Clutch Aligning Set

Litho in U.S.A.
 -.
JO750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-78) Engine Removal and Installation 0400-l

Section 4
ENGINE ~
CONTENTS OF THIS SECTION

Page Page
GROUP 0400 - ENGINE REMOVAL AND GROUP 0408 - VENTILATING SYSTEM
INSTALLATION General Information 0408-l
Removal .............................. 0400-3 Removal . 0408-l
Installation ............................. 0400-4 Repair 0408-l
Installation. 0408-l
GROUP 0401 - CRANKSHAFT AND MAIN
BEARINGS GROUP 0409 - CYLINDER HEAD AND
General Information .................... 0401-l VALVES
Removal .............................. 0401-l General Information . 0409-l
Repair ................................ 0401-l Removal . . . 0409-l
Installation ............................. 0401-4 Repair . . . 0409-I

GROUP 0402 - CAMSHAFT AND VALVE

ACTUATING MEANS
Installation

GROUP 0410 - EXHAUST MANIFOLD

0409-4
1
q
General Information .................... 0402-l General Information .................... 041 O-l
Removal .............................. 0402-i Removal .............................. 041 O-l
Repair ................................ 0402-3 Repair ................................ 041 O-l
Installation ............................. 0402-5 Installation ............................. 041 O-l

GROUP 0403 - CONNECTING RODS AND GROUP 0413 - FUEL INJECTION SYSTEM
PISTONS Fuel Injection Pump
General Information .................... 0403-l General Information .................. 0413-l
Removal .............................. 0403-l Removal ............................ 0413-l
Repair ................................ 0403-l Repair .............................. 0413-2
Installation. ............................ 0403-3 Installation and Timing ................ 0413-2
Fuel Injection Nozzles
GROUP 0404 - CYLINDER BLOCK General Information .................. 0413-4
General Information .................... 0404-l Removal ............................ 0413-4
Removal .............................. 0404-l Repair .............................. 0413-4
Repair ................................ 0404-l Installation ........................... 0413-5
Installation. ............................ 0404-2
GROUP 0416 - TURBOCHARGER
GROUP 0407 - ENGINE OILING SYSTEM General Information .................... 0416-l
General Information .................... 0407-l Removal .............................. 0416-l
Oil Pump Testing ................................ 0416-l
Removal ............................ 0407-l Repair ................................ 0416-2
Repair .............................. 0407-l Installation ............................. 0416-6
Assembly and Installation ............. 0407-2
Oil Pressure Regulating Valve
Removal ............................ 0407-2
Repair .............................. 0407-2
Installation. .......................... 0407-2
Oil Filters and Housing
Removal ............................ 0407-3
Repair .............................. 0407-3
Installation. .......................... 0407-3

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 4 Engine JD750 Crawler Bulldozer
0400-2 Engine Removal and Installation TM-l 136 (Nov-78)

Page Page
GROUP 0417 - WATER PUMP GROUP 0433 _ FLYWHEEL, HOUSING
General Information. .................... 0417-l AND FASTENERS
Removal. .............................. 0417-I General Information. .................... 0433-l
Repair. ................................ 0417-2 Removal ............................... 0433-l
Installation ............................. 0417-8 Repair ................................. 0433-l
Installation ............................. 0433-2 j
GROUP 0418 - THERMOSTATS, HOUSINGS
AND PIPING GROUP 0499 - SPECIFICATIONS AND
General Information. .................... 0418-l SPECIAL TOOLS
Removal ............................... 0418-l Specifications and Torque Values
Repair ................................. 0418-l Engine Break-in ...................... 0499-l
Installation ............................. 0418-2 Crankshaft and Main Bearings ......... 0499-2
Camshaft and Valve Actuating Means . . 0499-3
GROUP 0419 - ENGINE OIL COOLER Connecting Rods and Pistons. ......... 0499-8
General Information. .................... 0419-l Cylinder Block. ....................... 0499-9
Removal ............................... 0419-l Engine Oiling System ................ 0499-10
Repair. ................................ 0419-l Cylinder Head and Valves ............ 0499-l 1
Installation ............................. 0419-l Fuel Injection System ................ 0499-l 3
Turbocharger. ....................... 0499-l 7
, GROUP 0420 - FUEL FILTER Water Pump ........................ 0499-18
General Information ..................... 0420-l Thermostats, Housings and Piping .... 0499-18
R
Removal ............................... 0420-l Engine Oil Cooler ................... 0499-19
Repair ................................. 0420-l Starting System ..................... 0499-20
Installation ............................. 0420-l Fan Drive ........................... 0499-25
Flywheel, Housing and Fasteners 0499-25
GROUP 0421 - FUEL TRANSFER PUMP Special Tools
General Information. .................... 0421-l Engine Removal and Installation ...... 0499-26
Removal ............................... 0421-l Crankshaft and Main Bearings ........ 0499-27
Repair ................................. 0421-l Camshaft and Valve Actuating Means 0499-29
Installation ............................. 0421-l Connecting Rods and Pistons ......... 0499-30
Cylinder Block. ...................... 0499-32
GROUP 0422 - STARTING SYSTEM Cylinder Head and Valves ............ 0499-35
j Delco-Remy Starting Motor Fuel Injection System ................ 0499-38
General Information. .................. 0422-l Turbocharger. ....................... 0499-40
Removal. ............................ 0422-2 Water Pump ........................ 0499-42
Testing and Diagnosis ................ 0422-3 Starting System ..................... 0499-43
Repair. .............................. 0422-5
Installation ........................... 0422-9
John Deere Starting Motor
General Information. ................. 0422-I 0
Removal. ........................... 0422-l 1
Testing and Diagnosis ............... 0422-l 2
Repair. ............................. 0422-l 3
Installation .......................... 0422-l 9

GROUP 0429 - FAN DRIVE

General Information. .................... 0429-l
Removal. .............................. 0429-l
Repair. ................................ 0429-2
Installation ............................. 0429-2

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JD750 Crawler Bulldozer Engine 4
TM- 1136 (Apr- 79) Crankshaft and Main Bearings 0401-l

Group 0401
CRANKSHAFT AND MAIN BEARINGS
GENERAL INFORMATION To check end play, position a dial indicator against
the crankshaft gear (Fig. 1). Push crankshaft as far into
The forged steel crankshaft is supported in the cyl-
block as possible. Set dial indicator at zero. Using a bar
inder block by seven main bearings.
between the gear and the block gently force the
crankshaft out.
For further information on crankshafts and

clmB

0
main bearings refer to FOS Manual Engines.

REMOVAL
IMPORTANT: Do not apply too much pressure
with bar as this could damage bearings.

New end play will be 0.0020 to 0.0080 inch (0.051 to

Remove oil pan and oil pump (Group 0407) 0.203 mm). The maximum allowable end play is
0.0150 inch (0.381 mm).
Remove pistons and connecting rods (Group 0403).
New rear main thrust bearings will restore proper
Remove drive pulley and timing gear cover. end play.

Before removing crankshaft and main bearing caps, Crankshaft Gear

check crankshaft end play.
Check crankshaft gear for wear or damage. If nec-
essary, remove old gear with knife edge puller. Heat
Check main bearing caps for identifying numbers. If
new gear to 360°F (182°C) (don’t overheat). With
there are no numbers, stamp corresponding numbers Woodruff key in place, place the gear on the crank-
in one oil pan rail and in main bearing cap. Stamp the
shaft. Seat with JDH-7 Driver.
number in each main bearing cap off center to the

A
same side as the number in the oil pan rail. This will CAUTION: Oil fumes or oil can ignite
assure correct indexing of main bearing caps during above 380°F (193°C). Use a thermometer
installation. and do not exceed 360°F (182°C). Do not allow a
flame or heating element to be in direct contact
REPAIR
with the oil. Heat the oil in a well-ventilated area.
Checking crankshaft end play can give an indication Plan a safe handling procedure to avoid burns.
of thrust bearing wear.
Main Bearing and Crankshaft Journals
Inspect crankshaft journals and main bearings for
wear, scoring or damage.

If main bearings are assembled on journals, “Plas-

tigage” or equivalent can be used to determine clear- 1
ante.

l-Pry Bar 2-Dial Indicator

Fig. l-Checking Crankshaft End Play

Litho in U.S.A.
 4 Engine JD750 Crawler Bulldozer
0401-2 Crankshaft and Main Bearings TM- 1136 (Apr- 79)

Fig. a-Determining Main Bearing Clearance

NOTE: The use of pneumatic wrenches may dam-

age cap screw threads.
:..I
Remove main bearing cap and place a strip of Fig. 3-Measuring Crankshaft Journal
A “Plastigage” or equivalent in the center of the cap
El (about 3/4 of the width of the bearing) (Fig. 2). Use oil Use the journal measurements to determine if jour-
on “Plastigage” to prevent smearing. install cap iind nals are out-of-round or tapered. Specifications for
tighten to 85 ft-lb (115 Nm) (12 kg-m). journals and main bearings are as follows:

Remove the cap and compare width of “Plastigage” Measurement Specifications

with scale provided on side of package to determine
clearance. 0-D. of main bearing
journal . . . . . . . . . . . . . . . . . . . . 3.123 to 3.124 in.
NOTE: Use of “Plastigage” will determine wear, but (79.32 to 79.35 mm)
will not determine condition of either bearing or journal. Journal taper per inch of journal
length (max.) . . . . . . . . . . 0.0001 in. (0.002 mm)
If main bearings are disassembled, note that caps Journal out of round
are numbered so that they can be reinstalled on the (max.). . . . . . . . . . . . . . . . . . 0.0030 in. (0.076 mm)
main bearing bosses from which they were removed. Bearing to journal
clearance. . . . . . . . . . . _. . . 0.0016 to 0.0046 in.
When the crankshaft is removed and main bearings (0.041 to 0.117 mm)
disassembled, measure each main bearing journal at Maximum clearance . . . ~. . 0.0060 in. (0.152 mm)
several points (Fig. 3).
If wear is even, but out of specifications, dress
journals and select proper undersize bearing inserts.
Undersize inserts are available in 0.002, 0.010, 0.020
and 0.030 inch (0.05, 0.25, 0.51, 0.76 mm) sizes. If
journals are out-of-round or tapered, grind crankshaft
and use undersize bearing inserts.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Apr- 79) Crankshaft and Main Bearings 0401-3

NOTE: If undersize bearings are used, check bear- Using a dull chisel, score the wear ring in several
ing clearance after bearing caps have been tightened places (Fig. 4).
to 85 lb-ft (115 Nm) (12 kg-m). If undersize bearings
are too tight and clearance is not within specifications,
the journal and bearing will be wiped clean of oil
resulting in premature wear on parts.

Check thrust surfaces of the thrust bearing and

thrust bearing journal. Excessive wear will cause ex-
cessive end play. Be sure that journal will not damage
thrust flange on thrust bearing.

Crankshaft Damper
Service life of the crankshaft damper, located at the
front of the crankshaft, is affected by engine speed and
load variations as well as extreme heat or cold.

Replace the damper after 4500 or more hours or

every five years, whichever occurs first. Fig. 4-Score Wear Ring

A damper is considered failed when either run-out or IMPORTANT: Do not score wear ring too deeply ’
wobble of the outer ring exceeds 0.040 inch (1.02 mm) as it may damage the crankshaft surface. q!!!l
total indicated run-out. Replace also if there are visible
signs that the outer ring has slipped relative to the When wear ring is loosened remove it from crank-
rubber member or drive hub. shaft. /

Handle dampers with care. They are sensitive to Inspect the crankshaft flange for burrs or nicks. If
impacts such as being dropped or hammered on. necessary, clean flange with light file and fine emery
Impact damage can impair the “tuning effect” of the cloth.
damper, which prevents torsional damage to the en-
gine. NOTE: If cleaning is necessary, also use a light
coat of Permatex or equivalent on the flange before
Proper function of this damper is of major impor- installing new wear sleeve. Be sure that excess Per-
tance to crankshaft and timing gear life but is often matex is removed and no Permatex comes in contact
ignored during engine servicing. with new oil seal.

Crankshaft Rear Oil Seal, Housing, Front Oil Seal and Wear Sleeve
and Wear Sleeve
Check crankshaft front wear sleeve and oil seal for
Check crankshaft rear oil seal for damage or leak- damage or leaks. Leakage may result when burrs or
age. Replace with lip-type oil seal, wear sleeve, and foreign material are lodged between wear sleeve and
housing. oil slinger, preventing a seal.

To remove wear sleeve, score LIGHTLY with a dull

chisel. DO NOT score too deeply. Inspect crankshaft
flange for burrs or nicks. If necessary, clean up ends of
sleeve with a light file and emery cloth.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0401-4 Crankshaft and Main Bearings TM- 1136 (Apr- 79)

INSTALLATION Install main bearing caps with numbers corre-

sponding to numbers in oil pan rail and to the same
side as the numbers in the oil oan rail.

l-Number in Main Bearing Cap 3-Arrow

2-Number in Oil Pan Rail

Fig. d-Main Bearing Cap Positions

l-Thrust Bearing 3-Bearing Tang
2-Oil Hole 4-Piston Cooling Orifice
If numbers were stamped in main bearing caps (1,
fig. 5-Main Bearing Installation Fig. 6) at factory, install main bearing caps with
numbers corresponding to numbers in oil pan rail (2).
Before installing main bearings and crankshaft, The “arrow” (3) machined on the main bearing cap
check the piston cooling orifices (4, Fig. 5) mounted on number pad must point toward the cam shaft side of
each main bearing web. Remove only if visibly dam- the cylinder block.
aged. Check with wire to be sure they are not plugged.
Install orifices and tighten with 85 to 110 lb-in (9.6 to Before tightening cap screws on main bearing caps,
12.4 Nm) (0.98 to 1.27 kg-m). align upper and lower thrust flanges on main thrust
bearings. Tap the crankshaft to the rear and then to the
Install bearing with thrust flange in the main thrust front to line up the flanges. Tighten main bearing cap
bearing bore. Make sure the tangs on all bearings hit screws with 85 lb-ft (115 Nm) (12 kg-m).
the recesses in the bore and that the oil holes line up
with oil passages in the block. Turn crankshaft by hand. Crankshaft should turn
with little effort.
Apply a film of clean light oil to bearing surfaces and
to crankshaft main bearing journals.

Install crankshaft and align crankshaft gear with

other gears in gear train (Group 0402).

Install each bearing cap with the recesses and tabs

toward the same side of the engine as those on the
respective upper bearings in the block. Also make sure
bearing caps are installed on the bearing bosses from
which they were removed.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- I 136 (AW- 79) Crankshaft and Main Bearincls 0401-S

If abrasive was used to clean up crankshaft flange,

apply a thin coat of non-hardening gasket sealer to
crankshaft flange.

Position JD-251-2 Pilot Plate (1, Fig. 7) on crank-

shaft.

Fig. 8-JD297-1 Driver with 27489 Handle

Using JD297-1 Driver with 27489 Handle, drive

wear ring onto crankshaft until driver bottoms on pilot
plate (Fig. 8).

Remove pilot plate and drive wear ring onto crank-

l-JD-251-2 Pilot Plate 2-Wear Ring shaft until driver bottoms on crankshaft.

Fig. 7-JD-257-2 Pilot Plate

Remove any excess gasket sealer from area. In-
spect crankshaft and wear ring surfaces for nicks and
Position wear ring (2) over JD-251-2 Pilot Plate with
burrs. Remove nicks or burrs with emery cloth if not in
rounded edge out.
seal contact area.

Start wear ring on crankshaft by hand (avoid heavy

NOTE: Replace wear ring with nicks or burrs in seal
pressure or cocking of wear ring.
contact area. Keep seal and wear ring drivers clean
and free from nicks and burrs.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0401-6 Crankshaft and Main Bearings TM- 1136 (Apr- 79)

Place flywheel housing on a flat even surface. Install Use a mallet to drive in the oil seal until the driver
new rear oil seal. bottoms on the pilot.

Place JD297-2 Pilot (1, Fig. 9) and oil seal (2) in Replace crankshaft wear ring (Group 0401).
housing as shown.
Front Oil Seal

l-JD297-2 Pilot 2-Oil Seal

Fig. g-Pilot and Oil Seal in Place

It is not necessary to use 27409 Handle (1, Fig. 10) l-Oil Seal (Lips Inward) 2-JD250 Driver
with the JD297-1 (2) Driver to install the oil seal (3) but
I
it does help. Fig. 1l-Installing Front Oil Seal

Coat outer surface of seal with joint sealing com-

pound and inner surface with high temperature grease.
Support the oil seal bore area of timing gear cover.
Using JD250 Driver (2, Fig. 11) press in oil seal to j
bottom of bore with spring-loaded lip facing inward.

I-27409 Handle 3-Oil Seal

2--JD297-1 Driver

Fig. IO-Installing Crankshaft Rear Oil Seal

Litho in U.S.A.
 i-
JD750 Crawler Bulldozer Engine 4
TM-l 136 (Nov-75) Camshaft and Valve Actuating Means 0402-l

Group 0402
CAMSHAFT AND VALVE ACTUATING MEANS
GENERAL INFORMATION REMOVAL
The camshaft is driven at one-half engine speed
by the crankshaft gear and supported by four pres-
sure lubricated bores integral with the cylinder block.
Camshaft thrust is taken by a thrust plate fastened to
the fan end of the cylinder block. The camshaft lobes
are tapered. The cam followers are mushroom-
shaped with a crowned face.

Valve Lift Check

T34213N

l-Plug (2 used) 12--Retainer Lock

2--Rocker Arm Shaft (24 used)
J-Rowed Washer (2 used) 13-Valve Spring
4-Spring (5 used) (12 used)
6-Valve Rotator (12 used) 14-Push Rod (12 used?‘:““
&Rocker Arm w/Adjust- 16--Key
ing Screw (12 used) 16Thrust Plate
7-Adjusting Screw 17-Cap Screw (2 used)
(12 used) l&Camshaft Gear
Fig. I-Checking Valve Lift &Special Washer (6 used) 1 g--Camshaft
g--Cap Screw (6 used) 26-Tachometer Drive
)‘?. l&-Support ‘(6 used) Gear
* Measuring valve lift can give an indication of wear
11-Valve Stem Cover 21-Tappet (12 used)
to cam lobes, cam followers and push rods. 22-Valve (12 used)
(12 used)

Set valve clearance to 0.014 inch (0.36 mm) for in- Fig. P-Rocker Arm Assembly
take valves and 0.018 inch (0.46 mm) for exhaust
valves. Remove rocker arm assembly by removing the six
supports (10, Fig. 2).
Place dial indicator on valve rotator (Fig. 1). (Be
sure that valve is fully closed and the rocker arm Set No. 1 piston at “TDC” on compression stroke
moves freely.) Zero dial indicator. to align timing marks on crankshaft and camshaft
gears. This will aid in timing during assembly.
Manually turn engine in running direction. Check
indicator travel as the rocker arm moves valve to full Disconnect the battery ground straps.
open.
The engine or cylinder head need not be removed
Indicator should read 0.475 i 0.015 inch (12.07 2 unless desired.
0.38 mm) for intake valves and 0.470 + 0.015 inch
(11.94 t 0.38 mm) for exhaust valves. Remove fan, belts, and pulleys. A puller will be
necessary to remove pulleys.

litho in U.S.A.
 4 Engine JD750 Crawler Bulldozer
0402-2 Camshaft and Valve Actuating Means TM- 1136 (Nov-75)

Remove fuel transfer pump (see Group 0421).

Remove timing gear cover.

Using a wire with a go-degree bend on the end,

reach down through the top of the cylinder head and
raise cam followers off camshaft lobes. Secure wires
so that cam followers will not drag on camshaft dur-
ing removal.

Before removing camshaft, check camshaft end

play. End play on a new engine should be 0.0025 to
0.0085 inch (0.064 to 0.219 mm). However, end play
up to 0.0150 inch (0.381 mm) on an engine that has
been in operation is acceptable. Excessive end play
would indicate a worn thrust plate or surface.

Remove oil pan and oil pump.

q
Remove camshaft gear. l-Camshaft Gear 4-Oil Pump Gear
A 2-Upper Idler Gear S-Lower Idler Gear
34njection Pump Gear 6-Crankshaft Gear
Remove two cap screws from thrust plate and re-
move camshaft from cylinder bore. Fig. 3-Gear Train

NOTE: Do not allow cam lobes to drag in bores 1. Remove timing gear cover.
when removing camshaft.
2. Remove hex. nuts from the oil pump, drive
Timing Gear Train gears and cap screws from upper and lower idler
To service gear train and related parts, with the gears.
exception of the crankshaft, engine normally need
not be removed. If engine must be removed, see 3. Remove upper and lower idler gears from en-
Group 0401 of this section. gine front plate. Attach a puller to oil pump gear and
pull gear from shaft. NEVER PRY GEAR FROM
Whenever an engine is being completely recondi- SHAFT.
tioned or the crankshaft is being removed, the engine
front plate with gear assemblies should be removed 4. Remove oil pump if desired (Group 0404).
from the engine using the following steps:
5. Remove fuel injection pump and drive gear (see
Group 0413).

6. Remove camshaft.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (NOW75) Camshaft and Valve Actuating Means 0402-3

REPAIR

16

T36666N

l-Plug (2 used) 7-Racker Arm (12 used) 13-Gap Screw (2 used)

2-Rocker Arm Shaft &Washer (6 used) 14-Thrust Plate
3-Bowed Washer (2 used) g-Cap Screw (6 used) 16-Key
cl-spring (5 used) 1tbSupport (6 used) 1 &-Camshaft
5-Push Rod (12 used) 11-Valve Stem Cover (12 used) 17-Gear
6-Adjusting Screw (12 used) 1 I-Gear Is-Tappet (12 used)

Fig. 4-Camshaft and Rocker Arms

Camshaft Check thrust plate for proper thickness. New part

dimension is 0.1560 to 0.1580 in. (3.965 to
Check camshaft lobes for wear or damage. Mea- 4.015 mm). Thrust plate wear of 0.1510 in.
sure camshaft journals. Journals should be 2.1997 to (3.835 mm) is acceptable. If thrust plate wear or
2.2007 in. (55.863 to 55.898 mm) on a new cam- camshaft end play is excessive, check camshaft
shaft. An additional wear of 0.0010 in. (0.025 mm) is lobes, journal, and bushings for wear or damage.
acceptable. Replace camshaft if necessary.
To reinstall gear, install thrust plate and spacer.
If camshaft is replaced, cam followers must also
Support camshaft under first journal, install Woodruff
be replaced.
key, and place gear on camshaft with timing mark
facing away from camshaft. Press gear on until tight
Examine camshaft gear for worn or broken teeth or
against camshaft shoulder.
other damage.

If camshaft is replaced due to a damaged oil pump

drive gear, check gear and shaft on oil pump for
damage and replace as necessary.

Litho in U.S.A.
 4 Engine JU / m c,ra wler tblldozer
0402-4 Camshaft and Valve Actuating Means TM- 1136 (Nov-75)

Rocker Arm Assembly Idler Gears

Remove bowed washers (3, Fig. 4) and plugs (1) Be sure that the oil hole in the upper shaft is open.
from rocker arm shaft (2). Slide parts from shaft and Measure inside diameter of bushing (1.7520 inches
identify for reassembly. to 1.7530 inches L44.501 to 44.526 mm]) and out-
side diameter of shaft (1.7495 inches to 1.7505 inch-
Clean holes in rocker arms, rocker arm shaft, and es c44.437 to 44.463 mm]) to determine oil
rocker arm mounting brackets to insure proper lubri- clearance. If bushing replacement is required, press
cation of the rocker assembly. in new bushing to flush with either side of gear using
JD252 Driver.
Check rocker arms and rocker arm shaft for wear.
Rocker arm shaft O.D. is 0.7869 to 0.7879 in. The upper idler gear is pressure lubricated. If there
(19.987 to 20.013 mm). Shaft may be 0.7849 in. are signs of oil starvation, make certain that the oil
(19.936 mm) and still be acceptable. I.D. of rocker delivery hole in cylinder block is open.
arm bore is 0.7900 to 0.7920 in. (20.066 to
20.117 mm). Bore can also be worn an additional If idler gear shaft replacement is necessary, press
0.0020 in. (0.50 mm). in new spring pins to 0.2000 to 0.2800 inch (5.08 to
7.11 mm) above the shaft.
If a failed valve has been replaced, also inspect

qA
the rocker arm and push rod for that valve. Front Plate and Timing Gear Cover
Never pry or press against timing gear cover with
TIMING GEAR TRAIN :;
excessive force. The cover is cast aluminum alloy .1
and might be sprung or warped.
Checking Gear Train Backlash
If gear train noise is noted at the time of disassem-
bly it usually indicates excessive gear lash or dam-
aged gear teeth.

During disassembly measure gear train backlash.

Specified timing gear train backlash is as follows:

Gear Backlash

Crankshaft to upper idler . . .0.0027 to 0.0116 in.

(0.069 to 0.295 mm)
Upper idler to camshaft. . . . .0.0028 to 0.0135 in,
(0.071 to 0.343 mm)
Upper idler to injection
pump. . . . . . . . . . . . . . . . .
. . . .0.0028 to 0.0135 in.
(0.071 to 0.343 mm)
Crankshaft to lower idler. . . . .0.0027 to 0.0137 in.
(0.069 to 0.348 mm)
Lower idler to oil pump. . . . .0.0016 to 0.0147 in.
(0.041 to 0.373 mm) l-Oil Seal (Lips Inward) 2-JD-250 Driver

Fig, 5-Installing Oil Seal in Timing Gear Cover

If there is evidence of oil leakage on outside of

timing gear cover, replace crankshaft front oil seal as
outlined below.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-75) Camshaft and Valve Actuatina Means 0402-S

Coat outer surface of seal with joint sealing com- Rocker Arm Assembly
pound and inner surface with high temperature Install push rods in holes from which they were
grease. Support the oil seal bore area of timing gear removed.
cover. Using JD250 Driver press in oil seal to bottom
of bore with spring-loaded lip facing inward. Install valve stem wear caps on valve stems mak-
ing certain caps rotate freely.
INSTALLATION
Install rocker arm and shaft assembly on cylinder
Camshaft head. Tighten rocker arm clamp cap screws with 35
lb-ft (47 Nm) (5 kg/m).
If the cam followers have been removed, reinstall
after camshaft is installed.
Install all all other parts removed

Coat camshaft with high temperature grease such

After all parts are installed fill the lubricating sys-
as Texaco “Molytex Grease 0” or its equivalent and
tem with a proper oil and bleed the fuel system (see
install camshaft in block.
Group 0413).

Install fuel transfer pump (see Group 0421).

Timing Gear Train

With No. 1 piston on “TDC” of compression stroke,
align timing marks on camshaft and crankshaft.
Installing and Timing the Gear Train
The camshaft gear and injection pump gear must.
Install oil pump and oil pan.
be timed to the crankshaft when they are installed.
Install and time gear assemblies using the following
Turn camshaft gear to align thrust plate holes with
steps:
cylinder block holes. Install cap screws and tighten
with 35 lb-ft (47 Nm) (5 kg/m).
1. Turn crankshaft until No. 1 piston is at top dead
center (TDC) of its compression stroke.
Check camshaft for 0.0025 to 0.0085 inch (0.064
to 0.216 mm) end play.
If engine is stripped, position crankshaft so that
No. 1 fan-end connecting rod journal is at its highest
Install cylinder head, push rods, and timing gear
point toward the deck of the engine at this time. The
cover. Tighten cylinder head as described on page
keyway in the crankshaft front gear (not pulley key-
4-0409-4.
way) should point straight up toward the top of the
See Group 0413 and check injection pump timing. engine.
Check valve clearance. Using gasket cement, ce-
ment rocker arm cover gasket on the rocker arm Do not rotate crankshaft after “TDC” setting has
cover and install. Tighten cap screws with 20 to 25 been made.
lb-in. (2.3 to 2.8 Nm) (0.23 to 0.29 kg/m).
2. Install camshaft.
Install remaining parts, fill radiator with proper
coolant and engine crankcase with proper oil. Bleed
fuel system (see Group 0413).

Litho in U.S.A.
 4 Engine JD750 Crawler Bulldozer
0402-6 Camshaft and Valve Actuating Means TM-l 136 (Nov-75)

With engine at “TDC,” use tool JD254 to align the

timing mark on the injection pump gear between cen-
ters of crankshaft and injection pump shaft (Figure
7).

Use the timing mark on the injection pump drive

gear which indicates the number of cylinders in the
engine.

4. With camshaft and injection pump gears in-

stalled and timed, carefully install upper idler gear in-
to position using care not to rotate the timed gears.
Be sure inner thrust washer and idler gear shaft are
in place .on rear of idler gear shaft. Over front of
gear, install outer thrust washer and cap screw. Us-
ing a screwdriver between gears to prevent rotation,
secure upper idler gear to front plate and tighten to
6.5 lb-ft (88 Nm) (9 kg/m).
l-Timing Mark 2-JD-254 Timing Tool
5. install oil pump and drive gear.
A fig. S-Timing the Camshaft Gear
P Tighten oil pump gear hex. nut to 35 to 45 lb-ft (47
With engine at “TDC,” use tool JD254 to align the to 61 Nm) (4 to 6 kg/m) after gears have been timed
timing mark on the camshaft gear between centers of and lower idler gear installed so that gears may be
the crankshaft and camshaft (Figure 6). restrained with a screwdriver. Then stake threads on
shaft.
3. Install fuel injection pump and drive gear.
6. With oil pump gear installed, install lower idler
gear into position, using care not to rotate any gears.
Be sure special bolt, washer, inner thrust washer,
and idler gear shaft are in place on rear of idler gear
shaft. Over front of gear, install outer thrust washer
and cap screw. Tighten cap screw to 95 lb-ft (129
Nm) (13 kg/m).

After all gears are locked in place, recheck all tim-

ing marks with tool JD254, making sure that marks
still align between the centers of their respective
shafts and the center of the crankshaft with the en-
gine at “TDC.” Then remove timing screw and en-
gine rotation tool from flywheel and reinstall timing
hole cover.

Final Installation
Apply a thin coat of high temperature grease to the
inside lips of the front oil seal and install timing gear
cover. Be careful not to invert lips of oil seal while in-
stalling cover.
l-Timing Mark 2-JD-254 Timing Tool
Before installing gear cover on engine be sure that
fig. T-Timing the injection Pump Gear oil slinger is securely positioned over end of crank-
shaft with inside against gear.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Apr- 79) Connecting Rods and Pistons 0403-l

Group 0403
CONNECTING RODS AND PISTONS
GENERAL INFORMATION
Pistons are cast aluminum alloy, cam ground and
weight controlled. Each has two compression rings
and an oil control ring. Pistons are spray jet cooled.

Piston pins fit into bronze bushings in the connect-

ing rod. Each connecting rod has replaceable bear-
ing inserts.

REMOVAL
T30270N
Engine need not be removed to service pistons and
connecting rods. If engine is to be removed, see Group l-Water Passage 3-Block
0400. l--Liner 4--0.001 to 0.004 Inch
(0.02 to 0.10 mm)
Drain the crankcase and remove oil pan and cylin-
der head. Fig. l-location of Liner in Cylinder Block

Do not rotate crankshaft with cylinder head re- REPAIR

moved unless liners are bolted down. Bolt liners
down before removing pistons. Pistons
Remove carbon or ridge from liner bore with a Check clearance between piston and cylinder liner
ridge reamer before removing pistons. bore to determine if replacement is necessary. Mea-
sure clearance with a feeler gauge at bottom of pis-
NOTE: The use of pneumatic wrenches may ton skirt 90 degrees to pin bore. To establish taper
cause thread damage. and out of round, check liner 1 inch (25 mm) from
bottom and 1 inch (25 mm) from top, lengthwise and
Remove pistons keeping bearing inserts with their crosswise. Wear limits are as follows:
respective rods and caps. Mark rods, pistons, and
caps to assure correct assembly. Each connecting Specifications Measurement
rod and piston must be reinstalled in the cylinder
bore from which it was removed. Liner taper (maximum) . . . . 0.002 in. (0.05 mm)
Liner out-of-round
Measure height of bolted down liners before removal (maximum) . . . . . . . . . . .0.002 in. (0.05 mm)
from block. Height is 0.001 to 0.004 inch (0.02 to 0.10 Clearance between liner and
mm) above block. See Fig. 1. piston at bottom of skirt
(maximum) . . . . . . . . . . . .0.008 in. (0.20 mm)

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0403-2 Connecting Rods and Pistons TM- 1136 (Apr- 79)

Piston Rings and Ring Grooves

Piston rings should not be reused. Carefully exam-
ine ring grooves for wear or damage.

T.27564

l-Piston 4-Ring Land

l-Keystone Ring Groove S-Gauge Shoulder
4-Oil Ring Expander 3-Keystone Ring Groove Good Ring Groove
Compression Ring S-Snap Ring (2 used) Wear Gauge 7-Worn Ring Groove
2-Compression Ring &-Piston
3-Oil Ring 7-Piston Pin Fig. 34Jsing Ring Groove Wear Gauge

Fig. P-Piston with Three Rings Check top ring groove for excessive wear (Fig. 3)
by inserting a JDE-62 Ring Groove Wear Gauge in
If pistons are to be reused, remove carbon by
the groove. If gauge shoulders contact the ring land,
soaking in a 50 per cent solution of household deter-
the groove is excessively worn.
gent such as “Mr. Clean” and water for 30 to 60
minutes. Then scrub with a stiff bristle scrub brush.
Check the other two grooves for wear by inserting
Rinse piston in clear water and dry with clean towels.
a new ring in the proper groove at several points
around the piston. Measure clearance with a feeler

A
CAUTION: Do not soak for more than 60 gauge. If the clearance exceeds 0.008 inch
minutes. Avoid contact of solution with (0.20 mm), replace the piston.
your skin or eyes.
Piston Pins
IMPORTANT: Never clean pistons with wire
brush or abrasives. Inspect piston pin, pin bore in piston, and connect-
ing rod bushing for wear, damage, or deposits. Ex-
cessive clearance can result in severe damage to
engine. To check for correct clearance, see if piston
pin can be thumb pressed into position. Nicks or oth-
er damage must be avoided.

Always use new snap rings when installing piston

pins.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Apr- 79) Connecting Rods and Pistons 0403-3

Connecting Rods Rod and cap are an assembly; if one needs re-
placing both must be replaced.

Check assembly for straightness. If piston-to-liner

contact pattern is not centered on center of piston at
top and bottom of skirt, the rod needs to be replaced.

Check piston pin bushings. If necessary to install

new piston pin bushings, use JDE-286 Connecting
Rod Bushing Tool. Press bushing flush with connect-
ing rod bore edge. Hone bushings after they are in-
2 stalled for a “thumb press fit” into piston pins.
8
INSTALLATION
Assemble pistons and connecting rods, making
sure that identification marks on piston and rod are in
the same relative position as they were in at time of
disassembly.
4
.7'2756SN
Each connecting rod and piston must be rein- ~
stalled in the cylinder liner from which it was re- ICI
l-Piston Pin Bushing 3-Rod
moved.
2-Bearings 4-Gap Screw

Fig. 4-Connecting Rod and Bearings Coat piston pin with a light film of oil and insert in-
to piston pin bore. A properly fitted piston pin can be
Clean and inspect rods, caps, and bearings. Be pressed into position with the thumb. Install new pis-
sure oil-gallery-to-pin-bushing hole is clean and ton pin snap rings and check that rings are in
open. grooves of piston pin bore.

Check mating surface between rod and cap. Also Use a JDE-135 Ring Expander to install rings in their 1
check threads in rod and on cap screw for damage, respective grooves (Fig. 2). “Pip” marks on No’s. 1 and
high spots, etc. Replace cap screws whenever they 2 rings go toward head of piston.
are removed from connecting rod.
IMPORTANT: Incorrect size ring expander will
Rod bearing clearance can be checked with “Plas- damage rings.
tigage” if rod is connected to crankshaft. Clearance
between crankshaft and connecting rod bearings is NOTE: New rings are furnished with the correct
0.0016 (0.038 mm) to 0.0046 inch (0.114 mm). end gap; therefore, fitting to the liner is not neces-
sary.
NOTE: The use of ‘Plastigage” will determine
clearance between bearing and crankshaft journal,
but will not determine which surface is worn or the
condition of either bearing or journal surface.

.-
Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0403-4 Connecting Rods and Pistons TM- 1136 (Apr- 79)

Install expander in oil ring groove. install the oil Position JDE-84 Ring Compressor Sleeve on top
ring on the piston with the expander to the top of the of the liner (Fig. 5). Stagger ring gaps with the top
piston. Position oil ring gap opposite expander gap. ring gap over the piston pin. Carefully insert rod and
Be sure all rings are free to rotate freely in their piston assembly through the sleeve until the rings
grooves. contact the sleeve. With the piston and rings cen-
tered in the sleeve, push piston in liner.
Use short cap screws and large flat washers to
hold liners in place while pistons are installed. Apply engine oil to bearing inserts and crankshaft
rod journals. Small tangs on each half of the inserts
NOTE: The ring compressor must be clean and must fit recesses in rod and cap.
free of nicks and burrs and well oiled. Use oil on pis-
tons and piston rings before installing. NOTE: Dip connecting rod cap screws in engine
oil before installing.
NOTE: Be sure the words “FRONT” stamped on
the head of the piston and rod face toward the front Install caps so that large slot in caps fits large tang
of the engine. on connecting rod and small slot in caps fits small tang
on connecting rod. Tighten cap screws with 90 to 100
lb-ft (122 to 136 Nm) (12 to 14 kg-m).

IMPORTANT: Installing or removing connect-

ing rod and main bearing cap screws using
pneumatic wrenches may cause thread damage.

Rotate crankshaft several revolutions to be sure

there is no binding of parts.

Install oil pan and cylinder head.

l-Cap Screw 3-Compressor Sleeve

2-Piston “Washer

Fig. 5-Installing Pistons

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Apr- 79) Cylinder Block 0404-l

Group 0404
CYLINDER BLOCK
GENERAL INFORMATION
The cylinder block is a one-piece casting equipped
with seven main bearings.

The six cylinder liners are wet-sleeve replaceable

types. Each liner has a square rubber packing that
seals at a shoulder on the liner. Two O-ring packings
fit in grooves in the cylinder bore. The square and O-
ring packings seal the liner at the bottom of the cylin-
der bore. The top of the liner is sealed by cylinder
r3027ON
head gasket compression.
l-Water Passage 3-Block
REMOVAL 2-Liner 4-0.001 to 0.004 Inch
(0.02 to 0.10 mm)
Engine must be removed from unit to service cylin-
der block and cylinder liners (see Group 0400). Fig. l-Location of Liner in Cylinder Block

Drain the crankcase and remove oil pan and cylin- REPAIR
der head.
Cylinder Liners
Do not rotate crankshaft with cylinder head re- If piston and liners are to be re-used, liner bores
moved unless liners are bolted down. Bolt liners may be deglazed as follows:
down before removing pistons.
Mark liners and piston so reassembly is with origi-
Remove carbon or ridge from liner bore with a nal set.
ridge reamer before removing pistons.
Remove !iners and install in holding fixture (see
Remove pistons keeping bearing inserts with their “Special Tools”).
respective rods and caps. Mark rods, pistons, and
caps to assure correct assembly. Each connecting
rod and piston must be reinstalled in the cylinder
bore from which it was removed.

Measure height of bolted down liners before removal

from block. Height is 0.001 to 0.004 inch (0.02 to 0.10
mm) above block. See Fig. 1.

Fig. PRemoving Cylinder Liner

Use a 180-grit deglazing tool or hone. A GBD-

4-l/2 inch Tynex cylinder brush may also be used.
Cross hatch pattern should be approximately 45 de-
grees.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0404-2 Cylinder Block TM- 1136 (Apr- 79)

Immediately after deglazing, clean liner bores with Remove liner and carefully install a new dry pack-
hot water, soap and scrub brush. Rinse cylinder liner ing over the bottom end of the cylinder liner. Slide
bores with clean water until rinse water is clear. Dry packing firmly against the shoulder of the liner. Make
liner with clean towels. Wipe bores with clean engine sure that the packing is not twisted.
oil.
Dip the two cylinder block O-rings in AR54749 Soap
IMPORTANT: Solvents will not remove honing Lubricant or equivalent and install into the grooves in
residue. the cylinder block. Check that the O-rings do not
protrude outside the grooves and are not twisted.
Re-check liner-to-piston clearance at bottom of
skirt with feeler gauge. Coat the liner packing, sealing area of the liner and
cylinder block bore O-rings with AR54749 Soap Lubri-
Refer to “Basic Engine” in FOS Manual- cant or equivalent and install liner.

rlfa

0-
ENGINES for additional information on de-
glazing cylinder liners. NOTE: If you suspect that a packing may have
sheared or displaced during lowering into position,
the liner and packing assembly should be removed
Block and examined.

Clean block thoroughly with cleaning solvent or

pressure steam cleaning. Make sure all passages
and crevices are cleared of sludge, rust, and grease.
Be sure all coolant passages are cleaned of lime de-
posits and scale. Clean counterbore for liner flange.

NOTE: Clean counterbore for liner by scraping or

u&ins a “10-S” Tynex nylon brush.

Inspect the block for cracks or damage. Cracks, in

some cases, can be repaired by the cold weld pro-
cess if not in load bearing areas.

Replace dowel pins, pipe plugs, and studs as nec- Fig. 34nstalling Cylinder Liner
essary. Coat parts with joint sealing compound be-
fore installation. Work liners gently in place as far as possible by
hand. Finish seating liners by placing a wood block
INSTALLATION over upper end and tapping with hammer (Fig. 3).
Before installing liners be sure liner bores and
Cylinder liner will protrude over the top of the cylin-
packing grooves in block are clean.
der block more than normal due to uncompressed
packing and O-rings.
When installing new cylinder liners in block, first in-
stall liner without square packing and secure with
Clean cylinder liner bores with waterless hand
cap screws and washers. Using a depth gauge,
cleaner after installation in block. Wipe dry with clean
check the height of the flange on the liner in relation
towels. Coat liner bores with engine oil just before in-
to the cylinder block. The top of the liner should be
stalling pistons.
0.000 to 0.004 inch (0:OO to 0.10 mm) above the cyl-
inder block (4, Fig. 1) with packings removed from
the bottom of the liner. Check this several places
around the liner to make sure the liner is seated
squarely in the bore. of the cylinder block.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Apr- 79) Engine Oiling System 0407-I

-
Group 0407
ENGINE OILING SYSTEM
GENERAL INFORMATION OIL PUMP
The engine lubrication system consists of an en- Removal
gine oil pump, oil filters, oil cooler and oil pressure NOTE: Before removing oil pump check engine oil
regulating valve pressure (see Group 9010, Section 90).

The oil pump is located in the oil pan and is driven

Drain oil from engine.
by a gear located in the engine gear train. The pump
is a direct displacement type.
Remove engine oil pan.

Oil flows from the oil pump to the engine oil cooler
Remove attaching hardware and oil pump.
then past the pressure regulating valves located be-
hind the oil cooler housing in the block, then to the
Repair
filters and on to the oil galleries.
Remove idler gear (10, Fig. 1) from idler shaft;
The cooler bypass valve is located in the bottom of then support housing and press out shaft.
the oil cooler.
Inspect pump housing surface which attaches to
The engine oil filters are located on the right side cover for rough, burred, or warped conditions. The
of the engine. Half the oil flows through one filter ele- seal between pump cover and housing is dependent
ment and half through the other. upon these two surfaces being perfectly flat and
smooth.

T34218~

l-Cap Screw (2 used) S-Drive Gear 9-Discharge Tubs

2-O-Ring S-Nut 1 O-Idler Gear
3-Pump Housing with Shaft 7-Pump Cover 1 l-intake Screen Assembly
4-Pump Drive Shaft &-O-Ring (2 used)

fig. l-Oil Pump

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0407-2 Engine Oiling System TM- 1136 (Apr- 79)

Examine screen on cover to be sure it is clean and OIL PRESSURE REGULATING

wire mesh of the screen is not damaged. VALVE
Removal
Inspect inlet and outlet tubes for clogging.
Drain engine cooling system.
Check gears in housing for height and radial clear-
ances. Specifications are as follows: Remove engine oil cooler and oil filter housing.

Item Measurement Pull valve assembly with O-ring from cylinder

Thickness of gear _. . . . . . . .2.0070 to 2.0090 in. block.
(50.979 to 51.029 mm)
Gear bore depth . . . . . . . , . . .2.0105 to 2.0135 in. Repair
(51.067 to 51.143 mm)
Drive out spring pin and check spring and valve for
C.D. of gears.. . . . . . . . . . . . ..1.5290 to 1.5310 in.
damage.
(38.837 to 38.888 mm)
I.D. of gear bore . . . . . . . . . . . . 1.5340 to 1.5350 in.
(38.964 to 38.989 mm)

Carefully inspect pump drive shaft assembly for

wear, especially at points of contact.

NOTE: If pump drive shaft must be replaced, it

must be replaced as an assembly with gear and
groove pin. If pump idler gear shaft must be re-
placed, the pump housing must also be replaced with
the shaft.

Assembly and Installation

IMPORTANT: Apply high temperature grease to
both ends of oil pump gears before assembling oil
pump.
Fig. 2-Oil Pressure Regulating Valve
Install drive shaft with gear and idler gear. Both
gears must rotate freely. Spring should compress to 1.91 in. (48.5 mm) at
Install new O-ring on pump intake tube. Install intake 32.5 to 38.5 Ibs (145 to 171 N) (15 to 17 kg).
tube, pump cover and discharge tube on pump hous-
ing. Be sure that gears still turn freely. Install spring and valve in valve housing and retain
with spring pin.
Mount engine oil pump assembly on cylinder block
front plate and tighten cap screws to 35 lb-ft (47 Nm) (5 Installation
kg-m). Check shaft to be sure gears turn freely.
Follow removal procedure in reverse order.
Install oil pump drive gear, tighten gear nut to 35 to
45 lb-ft (47 to 61 Nm) (5 to 6 kg-m) and stake nut to Fill cooling and lubrication systems.
shaft.

NOTE: Check timing gear train information given in

Group 0402.

Install engine oil pan using new gasket. Tighten oil

pan cap screws to 30 lb-ft (41 Nm) (4 kg-m).

Fill engine lubrication system with proper lubricant.

Check engine oil pressure (see Section 90, Group

9010).

Litho in U.S.A.
JO 750 Crawler Bulldozer Engine 4
TM- 7 136 (Nov- 75) Engine Oiling System 0407-3

OIL FILTERS AND HOUSING Repair

Removal Replace oil filter elements every 200 hours of op-
eration or sooner if necessary.
Remove filter elements by screwing off housing.
The filter elements have a special bypass valve to
Remove housing by removing attaching hardware
protect the engine in case of filter clogging. Advise
and pulling housing off block.
the operator to replace only with genuine John Deere
filter elements supplied by his dealer.

Check oil passages in filter housing.

Installation
Follow removal procedure in reverse order.

A
cl.

l-Oil Filters 2-Housing

Fig. 3-Engine Oil Filters and Housing

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0407-4 Engine Oiling System TM-1 136 (Nov-75)

Litho in U.S.A.
_ ! JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-75) Ventilating System 0408-l --~.%,m

Group 0408
VENTILATING SYSTEM )
GENERAL INFORMATION
The engine is equipped with a ventilator outlet tube
which prevents pressure from building up in the
crankcase which could cause excessive oil consump-
tion.

REMOVAL
The ventilator outlet tube is located on the right
side of the engine.

Remove ventilator outlet tube.

REPAIR
Check tube for bent or damaged condition. Re-
place if necessary.

Clean inside of tube if it is restricted.

Check condition of O-ring in rocker arm cover. If

any damage or deterioration is noted, replace the O-
ring.

INSTALLATION
install tube in rocker arm cover being sure O-ring
and tube are properly seated.

Litho in U.S.A.
4 Engine JD 750 Crawler Bulldozer
0408-2 Ventilating System TM- 1136 (Nov- 75)

Litho in U.S.A.
JO 750 Crawler Bulldozer Engine 4
TM-1 136 (Nov-75) Cylinder Head and Valves 0409-l

- Group 0409
CYLINDER HEAD AND VALVES

GENERAL INFORMATION Injection nozzles extend below head and should be

removed to avoid possible damage to the nozzle tip
The cylinder head is a one-piece casting which
(see Group 0413).
holds the rocker arm assembly, valves and valve
springs.
Note location of all parts during removal for reas-
sembly.
The valve guides are integral with the cylinder
head. Valve seats are replaceable alloy inserts. The
NOTE: Do not rotate crankshaft with cylinder head
valves have chrome-plated stems and replaceable
removed unless all cylinder liners are secured with
wear caps. The exhaust valves are made of inconel.
cap screws and washers.
Valve rotaters are mounted above both intake and
exhaust valves.
REPAIR
REMOVAL
Cylinder Head
Disconnect battery ground straps.
Check to determine if cylinder head is flat and
smooth. If it is necessary to resurface the bottom
Drain coolant from engine before removing head.
deck of the head, no more than 0.030 inch (0.76
mm) may be removed.
The engine need not be removed to service the
cylinder head. It will be necessary to remove air
Check distance from the bottom deck of the cylin-
cleaner (Section 5, Group 0520), turbocharger
der head to the valves when seated. The distance for
(Group 0416), and intake manifold (Group 0414) and
intake valves must be 0.023 to 0.047 inch (0.58 to
exhaust manifold (Group 0410).
1.18 mm); the distance for exhaust valves must be
0.038 to 0.072 inch (0.96 to 1.83 mm).

Litho in U.S.A.
 -’ 4 Engine JD 750 Crawler Bulldozer
0409-2 Cylinder Head and Valves TM-l 136 (Nov-75)

Valves

T.347011

A l-Plug (2 used) O--Cap Screw (6 used) 16-Thrust Plate

P 2-Rocker Arm Shalt 16-Support (6 used) 17-Gap Screw (2 used)
3-Bowed Washer (2 used) il-Valve Stem Cover (12 used) 1&Gear
4-Spring (5 used) 12-Retainer Lock (24 used) 19-Tachometer Drive Gear
5-Valve Rotator (12 used) 13-Valve Spring (12 used) 26-Camshatt
GAdjusting Screw (12 used) 14-Push Rod (12 used) 21-Tappet (12 used)
7-Rocker Arm (12 used) 15-Key 22-Valve (12 used)
&Washer (6 used)

Fig. I-Valves and Rocker Arm Assembly

Remove cap screws from rocker arm supports (10, Check valve spring length on a spring tester. Free
Fig. 1) and remove rocker arm assembly. length of each spring may differ, but the compressed
length for each spring must be the same. Spring
Remove valve spring retainer locks (12) valve specifications are as follows:
stem covers (1 l), valve springs (13), rotators (5) and
valves (22). Identify each valve for reassembly into Item New Part

the guide from which it was removed. Free length (approx.) . . . . 2.12 inches (53.8 mm)

Inspect valve springs for alignment, wear and Compressed at 54 - 62 Ibs (240 to 276 N)
damage. Place springs on a flat surface to see that (24 to 28 kg)
they are square and parallel. Do not use springs that valve closed.. . . . . . . ~. . 1.81 inches (46.9 mm)
are cocked, crooked, broken or rusty.
Compressed at 133 - 153 Ibs (592 to 681 N)
(60 to 69 kg)
valve open . . . . . . . . . . 1.36 inches (34.5 mm)

valve stem caps should be replaced if pitted or

worn.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-78) Cylinder Head and Valves 0409-3

If valve rotators will not turn freely in one direction,

replace with new parts.

Inspect valves for wear or damage. Check for worn

or bent valve stems. Reface or replace valves as
necessary.

For information on valve refacing see

ms “Basic Engine” in FOS Manual-ENGINES.

0 0
Valve specifications are as follows:

l-Telescope Gauge 2-Valve Guide

Item New Part
Angle of valve face (intake). . . . . 29.5” Fig. P-Checking Valve Guide
(exhaust) . . . . . . 44.5”
O.D. of intake valve head . 1.8160 to 1.8260 in. Worn valve guides should be knurled using No.
(46.126 to 46.380 mm) D-20002WI knurling tool as directed by the tool manu- 1
O.D. of exhaust valve facturer.
head . .. . .. 1.570 to 1.580 in.
(39.88 to 40.13 mm) Valve Seat Insert
Valve stem diameter . 0.3715 to 0.3725 in.
(9.436 to 9.462 mm) Check valve seat insert for cracks, pits, carbon de-
posits, and excessive wear. Measure width and con-
Oversize valves centricity of the valve seat. Seat width is 0.0830 to
available . 0.003, 0.015 and 0.030 in. 0.0930 inch (2.108 to 2.362 mm). Runout between
(0.08, 0.38 and 0.76 mm) guide and seat should not be more than 0.002 inch
(0.05 mm).
Valve Guides
For information on valve seat refacing refer

cl
Measure valve guides for wear (Fig. 2). I.D. of a
ms to “Basic Engine” in FOS Manual-EN-
new guide is 0.3745 to 0.3755 inch (9.512 to 9.538
GINES.
mm). Clearance between new guide and new valve P
stem is 0.0020 to 0.0040 inch (0.051 to 0.102 mm).
The acceptable maximum clearance is 0.0060 inch
If seat inserts are not repairable, use JDE-77 Valve
(0.152 mm).
Seat Puller to remove intake valve seat inserts and
JDE-87 Valve Seat Puller to remove exhaust valve
seat inserts. Use pullers as recommended by the tool
manufacturer. Be careful not to damage cylinder head
when removing seat inserts.

Litho in U.S.A.
 4 Engine JD 750 Crawler Bulldozer
0409-4 Cylinder Head and Valves TM- 1136 (Nov- 78)

I// -FRONT /A

l-Valve Seat Insert 343eplacement Ring Fig. #-Proper Sequence for Tightening
P-Driver Cylinder Head Cap Screws

Fig. 3-installing New inserts NOTE: Numbers 3, 6, 11, 14, 19 and 22 cap screw
locations shown in Fig. 4 require the longer 4.50 inch
Chill both new insert and JDE-86 Adapter (ex- cap screws.
haust) and JDE-287 Adapter (intake) using dry ice

q
before installation. Use JDE-7 Driver to drive insert Use hardened flat washers under all cap screws. Dip
A
and replacement ring into place (Fig. 3). Check run- cap screws in oil prior to installation. Start cylinder
out and grind insert if needed to get maximum runout head to cylinder block cap screws by hand and tighten
of 0.0020 inch (0.051 mm). evenly to 95 lb-ft (129 Nm) (13 kg-m) following se-
quence in Fig. 4.
Assembly
Install push rods in holes from which they were
Valves
removed.
Apply John Deere Valve Stem Lubricant
(AR44402) to valve stems and guides. Install valves Install valve stem wear caps on valve stems mak-
into guides from which they were removed. Valves ing certain caps rotate freely.
must move freely and seat properly.
Install rocker arm and shaft assembly on cylinder
Install valve springs making certain that cylinder head. Tighten rocker arm clamp cap screws with 35
head end of spring is located correctly in the ma- lb-ft (47 Nm) (5 kg/m).
chined counterbore of the head.
Install all other parts removed.
Install rotators and new valve retainer locks. After
assembly “pop” each spring and valve assembly After all parts are installed fill the lubricating sys-
three or four times by tapping the end of each valve tem with a proper oil and bleed the fuel system (see
stem with a soft mallet. Group 0413).

INSTALLATION Valve Clearance Adjustment

Install cylinder head gasket dry. Remove flywheel housing timing hole cover.

NOTE: Head gasket will fit only one way. It should Use JDE-83 Engine Rotation Tool Set to position
not be necessary to force the gasket. The dowel pins No. 1 piston at Top Dead Center of its compression
on the cylinder block align the head. The use of several stroke. Turn flywheel until rotation tool timing pin en-
long bolts, with bolt heads removed, is recommended gages timing hole in flywheel (Fig. 5).
to correctly line up gasket and head.

IMPORTANT: Be sure cylinder block tapped

holes are clean and dry before installing head.

Lirho in U.S.A.
JO750 Cm wier Bulldozer Engine 4
TM-l 136 (Nov-75) Cylinder Head and Valves 0409-5

FAN END OF ENGINE-

6 5 4 3 2 1

EI EI EI EI EI EI

NO. 1 TDC COMPRESSION STROKE

6 5 4 3 2 1
EI EI EI EI EI EI

fig. 5-Setting “TDC”

“33830 NO. 6 TDC COMPRESSION STROKE

Adjust the valves indicated by the arrows on the Fig. 6-Adjustment of Valve Tappet Clearance
top half of Fig. 6 to 0.014 inch (0.36 mm) for intake
valves and 0.018 inch (0.46 mm) for exhaust valves. Turn the engine flywheel one revolution (360 de-
grees) until No. 6 piston is at “TDC” of its compres-
sion stroke.
A
Adjust the valves indicated by the arrows on the 0
bottom half of Fig. 6 to 0.014 inch (0.36 mm) for in-
take valves and 0.018 inch (0.46 mm) for exhaust
valves.

Remove the Engine Rotation Tool Set.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0409-6 Cylinder Head and Valves TM- 1136 (Nov- 75)

Litho in U.S.A.
 JD750 Crawler Bulldozer Engine 4
TM-l 136 (Nov-75) Exhaust Manifold 0410-l

Group 0410
EXHAUST MANIFOLD

GENERAL INFORMATION REMOVAL

Remove engine side shields, pre-cleaner, exhaust
stack, and hood.

Remove turbocharger (see Group 0416).

Remove exhaust manifold.

REPAIR
Check manifold for cracks and other defects and
replace if necessary. Clean passages of the mani-
fold.

INSTALLATION
Use John Deere Never Seez or equivalent on cap
Fig. l-Exhaust Manifold
screw threads.
//
The exhaust manifold is attached to the left side of
Install manifold on engffe using a new gasket.
the engine. /
Install the turbocharger (see Group 0416).
, Exhaust gases are used to operate the turbocharg-
er which is mounted on top of the exhaust manifold.
Install the hood, exhaust stack, pre-cleaner, and
engine side shields.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0410-2 Exhaust Manifold TM- 1136 (Nov- 75)

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM-1 136 (Nov-78) Fuel Injection System 0413-l -

Group 0413 >.#.

FUEL INJECTION SYSTEM
FUEL INJECTION PUMP

GENERAL INFORMATION Use the following method to remove the injection

pump:

Remove timing hole cover (5, Fig. 1) and install

timing window (19918) on injection pump.

Using a flywheel turning tool, rotate the engine un-

til timing mark on governor weight retainer is in line
with timing mark on cam ring (Fig. 2).

Install timing pin through flywheel housing into the

timing bore of flywheel to lock engine on TDC.

l-Throttle Linkage 4-Fuel Inlet

2-Fuel Return 5-liming Hole Cover
3-Injection Lines 6-Cam Advance
Mechanism

fig. I-Fuel injection Pump

The fuel injection pump pressurizes fuel and sends i-Governor Weight 2-Cam Ring
it through high pressure lines to the injection nozzles. Retainer

Fig. Z-injection Pump Timing Marks

REMOVAL
Clean the injection pump, lines, and area around Disconnect the speed control rod at injection
the pump with cleaning solvent or a steam cleaner. pump.

IMPORTANT: Never steam clean or pour cold

water on an injection pump while the pump is
running or while it is warm. To do so may cause
seizure of pump parts.

Litho in U.S.A.
 4 Engine JD750 Crawler Bulldozer
0413-2 Fuel Injection System TM- 1736 (Nov- 78)

A CAUTION: Escaping diesel fuel under

pressure can have sufficient force to pen-
REPAIR
For injection pump repair information and specifica-
etrate the skin causing serious personal injury.
tions, refer to TM-l 109 “Fuel Injection Equipment -
Before disconnecting lines, be sure to relieve all
Roosa Master” (Industrial).
pressure.

INSTALLATION AND TIMING

Fuel escaping from a very small hole can be
almost invisible. Use a piece of cardboard or wood, Check engine timing to make sure that No. 1 piston
rather than hands to check for escaping fuel. is at TDC. If the engine was rotated after the injection
pump was removed, crank the engine until No. 1 piston
If injured by escaping fuel, see a doctor at once. is starting the compression stroke. Install timing pin in
Serious infection or reaction can develop if proper the flywheel housing.
medical treatment is not administered immediate-
ly. The compression stroke can be determined by re-
moving the rocker arm cover and turning the engine
To relieve pressure in the fuel system, slightly crack until both valves are closed on No. 1 cylinder, and
high pressure injection line connections at nozzles. increased turning effort is noted. Continue turning the
engine until timing pin engages the timing hole in
i A modified standard 3/4” x 7/8” Flare Nut Wrench is flywheel.

iiki
required to loosen and tighten injection line flare nuts at
1 the injection pump (see “Special Tools”, Group 0499). Remove injection pump timing hole cover (5, Fig. 1)
and install timing window. Rotate pump drive shaft and
Disconnect injection pump inlet and pump-to-nozzle align the timing mark on governor weight retainer hub
fuel lines (3 and 4, Fig. 1). with the timing mark on the cam ring (Fig. 2).

IMPORTANT: When removing injection lines to Check pump mounting flange packing for damage or
nozzles, be sure not to turn outlet fittings in pump. wear. Replace if necessary.
Turning of these fittings may cause internal injec-
tion pump damage. Install injection pump on the engine being sure
Woodruff key enters the gear. Tighten the mounting
Disconnect fuel return line (2, Fig. 1). bolt nuts to 20 lb-ft (27 Nm) (3 kg-m).

Clean area around timing gear cover and remove Recheck pump timing mark alignment. If correct,
cover. Remove the injection pump drive shaft nut and install the washer and nut onto pump shaft and tighten
washer. Remove gear being careful not to lose Wood- with 140 to 150 lb-ft (190 to 203 Nm) (19 to 21 kg-m).
ruff key.
Remove the timing pin from cylinder block. Rotate
A modified l/2” Combination Wrench is required to the engine l-1/2 revolutions in direction of rotation,
remove and install the injection pump inner mounting then install timing pin in cylinder block. Continue to turn
stud nut (see “Special Tools”, Group 0499). engine until timing pin engages the timing hole in
flywheel. Recheck the alignment of injection pump
Remove mounting nuts. timing marks. If marks are not in line, loosen the pump
mounting bolts and bring marks into alignment by
Remove pump. Be sure to cap all injection pump turning pump. Retighten mounting bolts to 20 lb-ft (27
and fuel line openings to prevent entry of contami- Nm) (3 kg-m).
nants.
IMPORTANT: The normal backlash of gears is
enough to throw the pump timing off by several
degrees, resulting in poor engine performance.
Therefore, it is very important that the timing of the
pump be rechecked after it has been installed.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Apr- 79) Fuel Injection System 0413-3

Bleed the fuel system.

After bleeding the fuel system, the automatic cam

advance should be checked for proper adjustment.
High and low idle should be checked (Section 90,
Group 9010) if pump repairs have been made.

Bleeding
After removing any components of the fuel system,
air should be removed by bleeding. Bleeding is also
necessary whenever the fuel tank has been emptied.

T43745B u
Fig. 34njection Pump-To-Nozzle Line Connections

Remove caps from injection pump and fuel line

openings.

Connect the injection pump-to-nozzle lines. Refer-

ring to Fig. 3, connect No. 1 outlet first and continue
around the pump head in a counterclockwise direction
attaching lines in order of engine firing (l-5-3-6-2-4).

IMPORTANT: When removing and tightening Fig. &Fitter Bleed Plug

injection pump to nozzle lines, be sure not to turn
injection pump fittings. Turning of these fittings Loosen the filter bleed plug (Fig. 4). Pump the primer
may cause internal injection pump damage. lever on the fuel pump until most of the air bubbles in
Connect the speed control linkage, fuel inlet line and the filter are gqne and fuel flows from the bleed plug.
return line to the injection pump. Tighten the bleed plug and leave the primer lever in the
down position.
IMPORTANT: After fuel filter is bled and low and
high idle speeds are set (Section 90, Group gOlO), NOTE: If the primer does not pump fuel and no
synchronization of high and low idle between the resistance is felt at the upper portion of the lever
engine and transmission control valve must be stroke, turn the engine with the starter to change the
performed for proper machine performance. See fuel pump cam position.
Section 90, Group 9026 for procedure. Follow pro-
cedure 19 for low and high idle and procedure 4 for
transmission control valve synchronization.

Remove timing pin from engine, and plug openings.

Remove timing window and install injection pump

timing hole cover, and engine timing gear cover. Use
new gaskets when necessary.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0413-4 Fuel Injection System TM- 1136 (Apr-79)

FUEL INJECTION NOZZLES

GENERAL INFORMATION Disconnect nozzle from fuel line and at nozzle inlet
connector, (7, Fig. 5), using two wrenches. Disconnect
The injection nozzles (one for each cylinder) spray
leak-off line (2), by pulling boot off leak-off connector
high pressure fuel into the combustion chambers.
(1).
REMOVAL Remove nozzle hold down cap screw and washer
IMPORTANT: Disconnect battery ground strap (4) clamp (6) and spacer (5).
or turn battery disconnect switch to off before
working on nozzles close to the alternator to pre- Remove injection nozzle. If nozzle cannot be easily
vent accidental short circuits through tools. removed from cylinder head, use a JDE-38 nozzle
puller (Fig. 6).

l-Leak-Oft Connection 4-Cap Screw and Washer

2-Leak-Oft Line 6-Spacer l-JDE-36 Nozzle Puller 2-Injection Nozzle
34njection Nozzle 6-Hold Down Clamp
7-Nozzle Inlet Connector Fig. b-Using Tool to Remove Nozzles

fig. 5-Removing Injection Nozzle

IMPORTANT: Do not use a screwdriver or simi-

A
lar tool to pry injection nozzles from cylinder head.
CAUTION: Escaping diesel fuel under
Doing so may cause distortion and permanent
pressure can have sufficient force to pen-
damage to the nozzles.
etrate the skin, causing serious personal injury.
Before disconnecting lines, be sure to relieve all
pressure. Before applying pressure to the system,
REPAIR
be sure all connections are tight and that lines and IMPORTANT: Do not attempt to test or disas-
hoses are not damaged. Fluid escaping from a very semble nozzles unless the proper service tools are
small hole can be almost invisible. Use a piece of available. See TM-1 109 “Fuel Injection Equipment ,.
cardboard or wood, rather than hands, to search Roosa Master” (Industrial) for specifications, tools,
for suspected leaks. If injured by escaping fluid and testing procedures necessary to service in-
see a doctor at once. Serious infection or reaction jection nozzles.
can develop if proper medical treatment is not
received immediately. Remove carbon seal and seal washer (Fig. 7) from
nozzle.

Litho in U.S.A.
JD750 Crawler: Bulldozer Engine 4
TM- 1136 (Feb- 77) Fuel Injection System 0413-5

Install a new seal washer. Using JD-258 Seal In-

stallation Tool, install a new carbon seal. A nozzle
protector cap may be helpful in pushing the seat
from the pilot onto the nozzle body.
I

INSTALLATION
Clean nozzle bore in engine cylinder head using
JDE-39 Nozzle Bore Cleaning Tool.

Insert nozzle using a twisting motion.

Install nozzle hold-down spacer, clamp, washer,

and cap screw. Hand tighten cap screw.

Inspect injection lines for misalignment and rub-

bing. Replace as necessary. Adjust alignment as re-
l-Carbon Seal 2-Seal Washer
quired to prevent any tension or pre-load at the
3-Pilot
connection to nozzle and pump. Be sure line clamps
Fig. 74nstalling Seal Washer and Carbon Seal are properly located and tight.

Clean the exterior of nozzle by soaking in clean Connect fuel line to nozzle inlet and hand tighten. ‘!
L
solvent or diesel fuel. Then clean the spray tip with a
brass wire brush. Install leak-off fine. Torque nut to 25 - 35 lb-in (2.8 -
4.0 Nm) (0.29 - 0.40 kg/m).
IMPORTANT: Do not scrape or otherwise dam-
age the Teflon coating on the nozzle body above Tighten nozzle hold-down cap screw to 20 lb-ft (27
the carbon seal groove. This coating will become Nm) (3 kg/m), and tighten inlet connector to 35 lb-ft
discolored during normal service, but this is not (47 Nm) (5 kg/m).
harmful. Do not use a motor-driven brush to
clean the nozzle body. Bleed the fuel system.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0413-6 Fuel Injection System TM- I 136 (Feb-77)

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-75) Turbocharger 0416-l

Group 0416
TURBOCHARGER
GENERAL INFORMATION TESTING
The turbocharger is located on the top of the en-
Radial Bearing Test
gine near the exhaust manifold. The turbocharger
operates by means of exhaust gases to draw in
clean air from the air cleaner and deliver it under
pressure through the intake manifold to the combus-
tion chambers.

REMOVAL
Remove engine side shields, precleaner, exhaust
stack, and hood. Clean the area around the turbo-
charger.

Remove exhaust adapter. Plug or cover air open-

ing in the turbocharger.

Disconnect air intake pipe and plug or cover open-

ing. Disconnect oil inlet and outlet lines. Plug or cov-
er openings.

Remove attaching hex. nuts from basic turbo-

charger and remove turbocharger.

Fig. P-Radial Bearing Test

Perform this test to determine whether it is neces-

sary to replace the thrust bearings, radial bearing,
and/or rotating assembly of the center rotating as-
sembly. The radial bearing test should be made with
the turbocharger removed from the engine.

Using a mounting adapter and two-inch (50.8 mm)

indicator extension rod, fasten a dial indicator
(plunger type with one-inch 125.4 mm] travel) to the
turbocharger Fig. 2.

Move the rotating shaft toward the compressor and

l-Exhaust Adapter cl--Cap Screws then away from the indicator using care to move the
2-Exhaust Stack 5-Oil Line shaft in the same direction as the dial indicator trav-
3-Air Intake Hose
els.
Fig. l-Turbocharger Removal
Apply side pressure at both ends of the shaft to-
ward the dial indicator and then away from the indi-
cator.

Litho .in U.S.A.

4 Engine JD750 Crawler Bulldozer
0416-2 Turbocharger TM- 1136 (Nov--75)

Equal pressure should be applied to both ends of

the shaft at the same time. Check total dial indicator
movement to see that the range of travel is limited to
0.003-0.006 inch (0.08 to 0.15 mm). If movement is
not within these specifications, repair is necessary.

Axial End Play Bearing Test

Perform this test to determine if the rotating as-
sembly must be repaired or replaced.

l-Turbine Housing $-Clamp

P-Center Housing S-Cap Screw
S-Lock Plates

Fig. 4-Turbine Housing Removal

Mount a suitable holding fixture (see “Special

Tools”) in a vise (Fig. 5) and insert the turbine wheel
into the fixture. Remove the compressor wheel re-
taining nut using a double universal socket to avoid
Fig. 3-End Play Bearing Test possible bending of the shaft.

Refer to Fig. 6 and remove the compressor hous-

ing-to-back plate cap screws (7, Fig. 6) and pull off
compressor housing. Inspect for wheel rub or other
damage. Use care in removal and handling to avoid
damage to the wheel.

Fasten a dial indicator to the turbocharger so the

indicator tip rests on the end of the shaft (Fig. 3).

Move the shaft axially back and forth by hand. If

the total indicator reading is not within 0.001-0.004
inch (0.03 to 0.10 mm), the rotating assembly must
be repaired or replaced.

REPAIR
Disassembly
l-Holding Fixture 2-Compressor Wheel
Clean the exterior with a pressure spray of clean-
ing solvent before disassembly. As a part is re- Fig. 5-Removing Compressor
moved, place it in a clean protective container.

Remove the turbine housing-to-center housing cap

screws, lock plates, and clamps (Fig. 4). Tap with a
soft hammer if force is needed to remove the turbine
housing, being careful not to damage the turbine
wheel.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- I 136 (Nov- 75) Turbocharger 0416-3

R20445N

l-Compressor Housing g--Thrust Collar 17-Wheel Shroud

2-Lock Nut 1O--Bearing M-Piston Ring
3-impeller 11-Retaining Ring (4 used) 19-Turbine Wheel with Shaft
4-Backplate Assembly 12-Bearing (2 used) 20-Special Bolt (6 used)
6-Clamp (3 used) 13-O-Ring 21-Lock Plate (3 used)
6-Lock Plate (3 used) 14-Center Assembly Housing 22-Clamp (3 used)
7-Cap Screw (6 used) 15-Lock Plate (2 used) 23-Turbine Housing
I-Piston Ring 16-Cap Screw (4 used)

Fig. 6-Turbocharger

Remove the compressor wheel from the shaft.

Then remove the turbine wheel and shaft assembly
from the center housing, keeping it centered with the
bearings until it is clear of the housing. Fig. 7 shows
the turbine wheel assembly removed from the center
housing. The wheel shroud and piston pins may be
removed at this time.

Remove the back plate-to-center housing cap

screws and lock plates (16 and 15, Fig. 6). Then re-
move the back plate, by tapping with a soft mallet.

l-Wheel Shroud 3-Shaft and Wheel

2-Piston Ring Assembly

Fig. 7-Shaft and Wheel Assembly

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0416-4 Turbocharger TM- 1136 (Nov-75)

l-Rubber O-Ring 3-Piston Ring

l--Thrust Collar and Washer

Fig. &Removing Thrust Collar and Thrust Washer

l--bearing 2-Retaining Ring

Remove the thrust collar and thrust washer as Fig. B-Retaining Ring and Bearing Removal
shown in Fig. 8. Remove the rubber O-ring from
housing. Replace any part which fails to meet the require-
ments given in the inspection procedures.
Remove bearings and retainers from the center
housing (Fig. 9). Replace the following parts: O-ring (13, Fig. 6),
lock plates (6, 15 and 21), piston rings (8 and 18)
Cleaning and retaining rings (11).
Before cleaning, inspect parts for signs of burring,
Replace all damaged bolts.
rubbing, or other damage which might not be evident
after cleaning.
NOTE: If bearings and thrust washers show signs
of nicks, scores, shellac deposits, or foreign material
Soak all parts in clean carbon solvent for about 25
imbedment, replace them.
minutes. After soaking use a stiff bristle brush to re-
move all dirt particles. Dry parts thoroughly.
General - Parts must not show signs of damage, cor-
rosion, or deterioration. Threads must not be
NOTE: Normally, a light accumulation of carbon
nicked, crossed, or stripped.
deposits will not affect turbine wheel operation.

Shaft and Turbine Wheel - Turbine wheel must show

Inspection
no signs of rubbing, and vanes must not be torn or
Burnish or polish out minor surface damage. Use worn to a feather edge. Shaft must show no signs
silicon carbide abrasive cloth for aluminum parts and of scoring, scratches, or seizure with the bearings.
crocus abrasive cloth for the steel parts.

bitho in U.S.A.
JD 750 Crawler Bulldozer Engine 4
TM-1 136 (Nov-75) Turbocharger 0416-S

Compressor Wheel - Must show no signs of rubbing

or damage from foreign matter. Must be complete-
ly free of dirt or other foreign material. Impeller
bore must not be galled.

Seal Parts - Must show no signs of rubbing or scor-

ing of the running faces.

Housings - Must show no signs of contact with rotat-

ing parts. Oil and air passages must be clean and
free of obstructions.

Assembly
Be sure each part is clean before assembling. As
parts are assembled, cover openings to prevent entry
of dirt or other foreign material.

NOTE: If any particle falls into the turbocharger T27995N

during assembly, remove the particle immediately,

l-Sleeve Tool 4-Inner Ring Sleeve JD274-1)
even if extensive disassembly is required. P-Retaining Ring EL-Retaining Ring Installed 1
3-Ring Installer &-Bearing Installed cl
Check piston ring clearance in turbine wheel ring (JD274-3) 7-Outer Ring Sleeve (JD274-2)
groove. Check for burrs or foreign matter.
Fig. l0-/nsta//ing Retaining Rings

Install inboard retaining rings (Fig. 10) using retain-

Install piston ring on thrust collar over shaft, and ’
ing ring assembly tool (JD274). Lubricate bearings
flat against the center housing, engaging the pins in
with clean engine oil and insert in place. Install tur-
the back of the thrust washer.
bine side and compressor side bearing retaining
rings.
Install rubber O-ring in groove in center housing.

Install piston ring on turbine wheel shaft. With tur-

Be sure that thrust spring is installed in back plate
bine wheel shaft upright, guide through the wheel
(Fig. 11).
shroud and bearings. Do not use force to compress
piston ring into place. A gentle rocking and pushing
action will allow the piston ring to seat and the shaft
to bottom. A thin tool, such as a dental pick may be
used as an aid in compressing the ring if difficulty is
encountered.

Litho in U.S.A.
 4 Engine JD750 Crawler Bulldozer
0416-6 Turbocharaer TM- 1136 (Nov-75)

Check clearance between wheel shroud and tur-

bine wheel.

Install compressor housing on center housing.

Only hand tighten cap screws until turbocharger has
been mounted.

Orient turbine housing to center housing. Coat bolt

threads with a high temperature, anti-seizing com-
pound. Install bolts, clamps, and lock plates. Tighten
bolts with 100 to 130 lb-in (11.3 to 14.7 Nm) (1.15 to
1.50 kg/m) and bend ears of lock plates against
head of cap screw.

After assembly, push the rotating assembly as far

away as possible from the turbine end and check for
binding. Repeat check, pushing from the compressor
end.

q1
l-Spring P-Back Plate
INSTALLATION
Fig. 1 l-Back Plate Assembly
Just prior to mounting the turbocharger, prime the
IMPORTANT: Back plate and spring are sold turbocharger lubrication system. Fill the center hous-
only as an assembly. The installed depth of the ing with engine oil through the oil drain hole. Turn
spring is a controlled dimension. Therefore, do the rotating assembly by hand to lubricate the bear-
not remove or replace the spring by itself. Clean- ings and thrust washer.
ing can be done without removing the spring
from the back plate. Install turbocharger on engine. Use a new mount-
ing gasket.
Align mounting holes of center housing and back
plate and install back plate over shaft and thrust col- Check alignment of compressor housing to intake
lar. Use care not to break piston ring when engaging manifold. If necessary, rotate compressor housing so
seal in back plate bore. Back plate is easily installed that hose is properly aligned to intake manifold.
if open end of piston ring is engaged in back plate
bore first. Tighten the mounting stud nuts, then tighten the
back plate-to-compressor housing cap screws. Bend
Install back plate-to-center housing cap screws the ears of lock plate against head of cap screws.
and lock plates. Tighten cap screws and bend ears
of lock piates against head of cap screw. When installing turbocharger exhaust adapter and
exhaust elbow be certain that the installation does
install compressor wheel and tighten nut with 18 to not apply a force on the turbine housing. The ex-
20 lb-in (2.0 to 2.3 Nm) (0.21 to 0.23 kg/m) then haust adapter must have l/16 inch (1.6 mm) mini-
tighten through an angle of 90”. mum end play and rotate freely.

Check axial end play and radial movements. If not IMPORTANT: Inspect hose and clamps. Re-
within 0.003 to 0.006 inch (0.08 to 0.15 mm) (bearing place as necessary. Compressor to intake mani-
clearance) or 0.001 to 0.004 inch (0.03 to 0.10 mm) fold hose clamps must be properly positioned
(bearing end play), recheck parts to determine the and tightened.
cause.

Litho in U.S.A.
,..
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-75) Turbocharger 0416-7

Inspect the air cleaner-to-turbocharger hoses to When starting engine with a new or repaired-turbo-
see that they are in good condition. If they are not, charger, disconnect fuel injection pump electric shut-
replace with new ones. install air intake pipe, and off connection and crank the engine with the starter
tighten hose clamps securely. until the engine oil pressure indicator light goes out.
Start and run engine at low idle while checking oil in-
IMPORTANT: Since the greatest amount of let and air passage connections for leaks.
suction occurs between the air cleaner and tur-
bocharger, it is essential that the hose connec-
tions are tight to prevent entry of dirt into the
engine.

Connect the lubricating oil inlet manifold and return

pipe to the turbocharger, using new gaskets.

A
•I

Lifho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0416-8 Turbocharger TM-1 136 (Nov-75)

Litho in U.S.A.
JO750 Crawler Bulldozer Engine 4
TM- 1136 (Mar-78) Wafer Pump 0417-l

Group 0417
WATER PUMP
GENERAL INFORMATION REMOVAL
The centrifugal-type water pump is attached direct- Remove grille screen and baffle for access to radi-
ly to the cylinder block and is driven by the fan belt. ator drain cock. Drain the radiator.
If the seals in the pump become worn or damaged,
water will escape through the drain hole in the bot- Remove engine side shields.
tom of the pump housing.
Remove fan guards, shroud and fan. Remove fan
belts.

Disconnect hoses from water pump. Remove water

pump from engine.

11

\
8 9 10 16
\ \
u--y ‘\
\

T42875

l-Cap Screw g-Inner Seal lOover

2-Special Washer lO-Housing lg.-Seal
3-Fan Pulley 1 l-Pipe Plug 20-Stud
4-Outer Seal 12-Gasket 21-Lock Washer (2 used)
5-Snap Ring 13-Impeller Insert 22-Nut
S-Ball Searing (2 used) 14-Impeller Insert 23-Special Screw
7-Shaft 15-Insert and Cup 24-Gap Screw
&Cap Screw (4 used) %--Impeller 2'lube
17-Gasket

Fig. l-Water Pump

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0417-2 Water Pumt2 TM- 1136 (Mar-78)

REPAIR Drive outer seal (1, Fig. 3) from housingusing a

center punch and notches (2) provided m housirig.
Disassembly -
Use D-01200AA Puller (1, Fig. 2) to remove fan
pulley (2) from water pump shaft.

l-Outer Seal 2-Notch

Fig. 3-Removing Outer Seal

l-D-01200AA Puller 2-Fan Pulley

Fig. P-Removing Fan Pulley

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Mar-78) Water Pump 0417-3

Remove snap ring (4, Fig. 4).

Remove the cover plate (9) and gasket (1).

Select a drift (1, Fig. 5) slightly smaller than the

inside diameter of the impeller (2). Supporting the
pump housing from the pulley side, press the water
pump shaft (5, Fig. 4), inner bearing (14), and outer
bearing (7) out of the pump housing.

Ip57647

1 -Gasket 9-Cover Plate

2-Pump Housing 10-0.015 to 0.035 in.
3-Fan Pulley (0.38 to 0.89 mm)
4-Snap Ring ll--Cupped Rubber Insert l-Drift P-Impeller
5-Water Pump Shaft 12-Water Pump Seal
6-Outer Seal 13-Ceramic Insert fig. 5-Removing Shaft
7-Outer Searing 14lnner Searing
&Impeller %-Inner Seal
16--0.010 in. (0.25 mm) Remove the impeller.
(maximum)
Remove the cupped rubber insert (11) and ceramic
Fig. 4-Water Pump Assembly insert (13) from counter bore in the impeller.

Remove the water pump seal (12). The outer shell is

made of rubber allowing the seal to be peeled out of
the housing.

bitho in U.S.A.
4 Engine JD 750 Crawler Bulldozer
0417-4 Water Pump TM- 1136 (Mar-78)

Using 27495 and 27505 Drivers (1, Fig. 6) and

27488 Handle, drive the inner seal (15, Fig. 4) out of its
bore from the impeller side.

NOTE: If the inner bearing remained in the housing

during shaft removal it will be removed with the inner
seal.

I-DQt217AA Knife-Edge Puller 2-Outer Bearing

fig. 7-Removing Outer Searing

Using D-01217AA Knife-edge Puller (1, Fig. 8) or

other suitable tool, support the inner race of the inner
bearing (2) and press the shaft out of the bearing.

l-27495 and 27505 Drivers 2-27488 Handle

fig. d-Removing Inner Seal

Scrape gasket residue from pump housing and

cover plate.

Using D-0121XA Knife-edge Puller (1, Fig. 7), or

other suitable tool, support the inner race of the outer
bearing (2) and press the shaft out of the bearing.

I--D-01217AA Knife-Edge Puller 2-Inner Bearing

Fig. B-Removing Inner Searing

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Apr- 79) Water Pump 0417-5

Inspection
Inspect pump parts for wear or damage. Replace as
necessary.

Pump leakage can be caused by one or more of the

following conditions:

Cracked housing.

Scratched, damaged, or worn water pump seal.

Cracked, loose, or damaged ceramic insert.

Loose or defective cupped rubber insert.

Defective water pump shaft.

Leakage at the drain hole in the pump housing

usually indicates a leaking water pump seal. Replace
seal, cupped rubber insert, and ceramic insert as nec-
essary.
l-JDE-111 Seal Driver 3-Inner Seal
2-27488 Handle
Inspect housing for damage behind the impeller.
Replace if metal has been scraped away by impeller. Fig. 94nstalling Inner Seal

Assembly Using tubular drivers against the inner races, press

the inner bearing (14, Fig. 10) and outer bearing (7)
Insert JDE-112 Seal Driver (I, Fig. 9) and 27488
onto the shaft until they bottom against their respective
Handle (2) in inner seal (3) with open face of seal
shoulders.
toward driver. Drive seal into housing from fan pulley
end until driver bottoms.
Pack the area around the shaft between the bear-
ings with AT30408 High Temperature Grease or an
Pack inner and outer bearings with a high tempera-
equivalent.
ture grease.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0417-6 Water Pump TM- I 136 (Apr- 79)

IMPORTANT: Never use excessive force if

> bearings must be driven into place by, applying
pressure through the balls. To do so may damage

3
9 bearings and cause premature failure.

Position the shaft bearing assembly over the pulley

@
end of the housing. Lower it into place in the housing
using care not to hit the inner seal. The bearings
should slip into place in the housing with little resis-
tance. A very light tap with a soft face hammer on the
fan pulley end of the shaft may be necessary if resis-
tance is felt.

Install thinnest snap ring (4, Fig. 10) of four which

are available in snap ring groove in end of housing.
The following size snap rings are available:

0.067 in. (1.70 mm)

0.077 in. (1.96 mm)
0.087 in. (2.21 mm)
0.097 in: (2.46 mm)

Check shaft end play with a dial indicator as shown

in Fig. 11.

TS76a7

l-Gasket 9-Cover Plate

2-Pump Housing 10-0.015 to 0.035 in.
3-Fan Pulley (0.38to 0.89 mm)
4-Snap Ring 11-Cupped Rubber Insert
5-Water Pump Shaft 12-Water Pump Seal
g-Outer Seal 13-Ceramic Insert
7-Outer Bearing M-Inner Bearing
84mpeller 154nner Seal
16-0.010 in. (0.25 mm)
(maximum)

Fig. lo-water Pump Assembly

Fig, 1 l-Checking Water Pump Shaft End Play

Choose the snap ring which will allow a maximum

shaft end play of 0.010 in. (0.25 mm). Remove the thin
snap ring and install correct one.

Litho in U.S.A.
JO 750 Crawler Bulldozer Engine 4
TM-1 136 (Mar-78) Wafer Pump 0417-7

Install the outer seal, with the open side of the seal Support pump assembly on pulley end of shaft (1,
toward the bearings, in the pump housing until it bot- Fig. 13) and press impeller on bearing shaft (vanes
toms in the housing. toward housing) until impeller vanes have 0.015 to
0.035 in. (0.38 to 0.89 mm) (2, Fig. 13 and 10, Fig. 10)
Sparingly coat the flange portion of the water pump clearance with pump housing (Fig. 13).
seal (12, Fig. 10) with joint sealing compound. Press
seal into housing by hand until flange bottoms on
housing (Fig. 12). Wipe away any excess joint sealing
compound.

l--Support Shaft 24.015 to 0.035 in. (0.38 to 0.89 mm)

Fig. Id-lnsfalling Impeller

fig. 72-Wafer Pump Sea/ lnsfalled

Using a drift which is smaller than the impeller end of
the water pump shaft, press shaft into fan pulley untiJ
shaft bottoms on pulley (Fig. 14).
Place ceramic insert (13, Fig. IO) in cupped rubber
insert (11) with “V” groove on ceramic insert toward
cupped rubber insert. Be sure parts are dry and clean.

Dip inserts in light oil. and install in impeller (8)

counterbore with cupped rubber insert against im-
peller. This is best accomplished by placing one side of
insert in counterbore then pressing the outer side in
place. The sides of both inserts should be a uniform
distance all of the way around the impeller counter-
bore.

Apply a coating of clean light oil to the sealing

surfaces of the water pump seal and the ceramic
insert.

Fig. 14-installing Fan Pulley

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0417-8 Water Pump TM- 1136 (Mar-78)

Using a new gasket, install cover plate (9, Fig. 10)

on water pump.

INSTALLATION
Install water pump on engine using new gaskets.

Install fan and hoses to water pump.

Install engine side shields.

Fill radiator with John Deere Summer Engine Cool-

ant or antifreeze solution.

Litho in U.S.A.
JD 750 Crawler Bulldozer Engine 4
TM-1 136 (Nov-75) Thermostats, Housings and Piping 0418-l

Group 0418
THERMOSTATS, HOUSINGS, AND PIPING
GENERAL INFORMATION REMOVAL
Remove grille screen and baffle for access to radi-
ator drain cock. Drain radiator.

Remove left engine side shield. Remove thermo-

stat housing and cover.

REPAIR

Fig. l-Thermostat Housing and Cover

The thermostat housing contains two thermostats

which when open allow coolant flow through the radi-
ator and engine.

When the engine is cold the thermostats close off

the coolant flow to the radiator. During this time the 243750N

thermostats allow coolant flow through a bypass tube l-Cap Screw 7-Pipe Plug
allowing coolant circulation through the engine only. P-Lock Washer (5 used) 8-Cap Screw (2 used)
3-Cover B-Gasket
4-Gasket lO-O-Ring (2 used)
When the engine reaches normal operating tem-
5-Thermostat (2 used) 1 l-Bypass Tube
perature of 180°F (82X), the thermostats begin to 6--Housing
open allowing coolant flow through the radiator and
engine. As the thermostats open, flow through the Fig. P-Thermostats and Housing
bypass tube is closed off. The thermostats are fully
open at 190°F (88°C).

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0418-2 Thermostats, Housings and Piping TM-1 136 (Nov-75)

If the engine has been running too cool or too hot, INSTALLATION
carefully inspect the thermostats for defects, If visual
Install housing using a new gasket (9).
inspection fails to disclose any defects, test the ther-
mostat in hot water to check for proper closing.
Fill radiator with soft clean water and proper addi-
tive.
Using a new gasket (4, Fig. 2) and O-rings (10)
during assembly.

Litho in U.S.A.
..
JD750 Crawler Bulldozer Engine 4 .
TM- 1136 (No v- 75) Engine Oil Cooler 0419-l

Group 0419
ENGINE OIL COOLER
GENERAL INFORMATION Drain coolant from radiator.

The engine oil cooler is located on the left side of

Drain oil from engine.
the engine and uses engine coolant to lower engine
oil temperature. The cooler bypass valve is located in
Remove coolant inlet and outlet lines.
the bottom of the oil cooler.
Remove cap screws attaching cooler to engine
Oil flows to the engine oil cooler, then past the
and remove cooler.
pressure regulating valve. The valve is located be-
hind the oil cooler housing in the block.
REPAIR
REMOVAL Remove cap screws securing cooler top and bot-
tom covers.

Check coolant passages for damage or buildup of

lime or other foreign material.

Clean oil passage to remove any foreign material.

To check oil cooler bypass valve assembly, re-

move bypass valve bushing, valve and spring. Check
for damage.

Check oil cooler bypass valve spring for bent or

broken coils. Check length of spring; free length
should be 2.70 in. (68.5 mm), and 1.91 in. (48.5 mm)
compressed at 32.5 to 39.5 lb. (145 to 176 N) (15 to
18 kg).

l-Water Outlet 4-Attaching Points Install spring and valve in cooler housing. Gently
~--TOP Cover 6-Bottom Cover drive valve bushing into housing until bushing bot-
3-Water Inlet 6-Oil Cooler
toms in housing.
fig. l-Engine Od Cooler
INSTALLATION
install upper and lower covers on cooler and install
cooler on engine using new gaskets and seals.

Attach coolant inlet and outlet lines.

Fill radiator with clean soft water and proper addi-

tive.

Fill engine with proper oil.

Litho in U.S.A.
..
* 4 Engine JD750 Crawler Bulldozer
0419-2 Engine Oil Cooler TM-1 136 (Nov-75)

bitho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM-1 136 (Nov-75) Fuel Filter 0420-l

Group 0420
FUEL FILTER
GENERAL INFORMATION REPAIR

fig. I-fuel Filter

T43753N
The fuel filter, mounted on the right side of the en-
gine, filters the fuel before it enters the injection
l-Bleed Screw (2 used) 4-Element
pump. 2-Packing (2 used) 6-Pipe Plug
3-Spring 6-Body
REMOVAL
fig. P-fuel filter Assembly
To remove filter element, pull off retaining spring
and slip off cover and filter element. Clean body (6, Fig. 2) and check openings in body
for clogging.
To remove filter body, disconnect and cap inlet
and outlet fuel lines. Remove cap screws securing Replace element as needed. , I &, .
body to mounting bracket.
INSTALLATION 1

Follow removal procedure in reverse order.

Bleed the fuel system (Group 0413).

Litho in U.S.A.
4 Engine JD 750 Cra wier Bulldozer
0420-2 Fuel Filter TM-l 136 (Nov-75)

Litho in U.S.A.
 .t
JD 750 Crawler Bulldozer Engine 4 ’
TM-l 136 (Nov-75) Fuel Transfer Pump 0421-l
.

Group 0421
FUEL TRANSFER PUMP ~
GENERAL INFORMATION REMOVAL
Disconnect fuel lines at pump. Remove cap screws
and remove pump.

REPAIR
Refer to Fig. 1 when disassembling and assem-
bling the pump.

To remove or install primer lever, compress rocker

arm lever.

Further disassembly of the transfer pump is not

possible.
T23206N

INSTALLATION

q
l-Gasket 4-Primer Lever
2-Packing [i-Fuel Pump
3-O-Ring Follow removal procedure in reverse order. Bleed ’
fuel system (Group 0413).
Fig. l-Fuel Transfer Pump

The fuel transfer pump draws fuel from the fuel

tank and sends it to the fuel filter.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0421-2 Fuel Transfer Pump TM-1 136 (NOW75)

I
!

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov- 75) Starting System 0422-l ,.

Group 0422
STARTING SYSTEM
DELCO REMY STARTING MOTOR
GENERAL INFORMATION

The starting motor consists of a drive housing, mo- Solenoid Switch

tor drive and pinion, shift lever, field frame, solenoid,
The solenoid switch consists basically of two wind-
armature, field coil assembly, brushes and commuta- ings mounted around a hollow cylinder containing a
tor end frame. moveable core or plunger. A shift lever is connected
to the plunger, and a push rod and contact disk are
The starting motor has a totally enclosed shift lever
assembled in line with the plunger.
and solenoid plunger to seal out dirt, ice, and water.
Positive lubrication to the bushings is provided by oil-
The two windings in the solenoid are called the
saturated wicks. hold-in winding and the pull-in winding. The hold-in
winding contains many turns of fine wire, and the
Armature pull-in winding the same number of turns of larger
The armature is supported on three bushings in wire.
the drive housing, lever housing and commutator end
frame. The armature assembly consists of a stack of Bendix Positork Drive
iron laminations located over a steel shaft, a commu-
tator assembly and the armature windings. The wind-
ings are heavy copper ribbon, assembled into slots in
the iron laminations. The winding ends are soldered
or welded to the commutator bars which are electri-
cally insulated from each other and from the iron
shaft.

Field Windings
The frame and field assembly consists of field
windings assembled over iron pole pieces which are
attached to the inside of a heavy iron frame. The iron
frame and pole shoes not only provide a place onto
which the field coils can be assembled, but also pro-
vide a low reluctance, or low resistance path for the
magnetic flux produced by the field coil windings. 1-Sprags 3-Shift Collar
2-Pinion

Fig, l-Bendix fositork Drive

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0422-2 Starting Sys tern TM- 1136 (Nov-75)

The Bendix motor drive is constructed and oper- REMOVAL

ates like the overrunning clutch drive, except that a
series of sprags replaces the rollers between the
shell and sleeve. The sprags are held against the
shell and sleeve surfaces by a spring. This assembly
is then splined to the armature shaft with a shift coi-
lar on the end of the sleeve (Fig. 1).

Movement of the shift lever against the collar

causes the entire assembly to move endways along
the splined shaft, and the pinion teeth to engage the
ring gear. If a clash of teeth should occur, continued
movement of the shell and spiral splined sleeve
causes the pinion to rotate and clear the teeth. The
compressed meshing spring then forces the pinion
into mesh with the ring gear. If the pinion does not
clear before the two retainer cups meet, shift lever
movement is stopped by the retainer cups and the
operator must start the engagement cycle over
again. This prevents closure of the switch contacts to
the motor with the pinion not engaged, which would
result in damage due to spinning meshes: On the l-Battery Terminal &White Wire to
second attempt, the pinion will engage in a normal P-Motor Terminal Switch Terminal
I-Switch Terminal B-Red Wires to Battery
manner.
4-Battery Positive Cable Terminal

With the pinion engaged and the switch closed, Fig. 2-Solenoid and Starting Motor
torque is transmitted to the pinion through the
sprags. The sprags tilt slightly and are wedged be- Turn off battery disconnect switch.
tween the shell and sleeve. When the engine starts,
the ring gear drives the clutch faster than the arma- Disconnect and tag all wires and cables from sole-
ture, and the sprags tilt in the opposite direction to noid and starting motor.
allow the pinion and sleeve to overrun the shell and
armature. To avoid prolonged overrunning, the start Remove the two mounting cap screws and mount-
switch should be released as soon as the engine ing nut behind the starting motor.
starts.
Remove starting motor from engine.
Never run the starting motor more than twenty
seconds at a time or overheating will result. Allow
motor to cool at least two minutes before running it
again.

For additional information on starting mo-

F@s tors, refer to “Starting Circuits” in FOS
Manual - ELECTRICAL SYSTEMS.
Cl Q

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Apr- 79) Starting System 0422-3

TESTING AND DIAGNOSIS High Ammeter Reading

Windings are grounded or short circuited.
Solenoid Tests
Low Ammeter Reading
Testing Pull-In Windings
Excessive resistance is present (usually in a con-
Disconnect field connector from solenoid motor ter-
nection).
minal. Connect ammeter in series with a carbon pile
resistor to switch terminal and to battery. Connect No Ammeter Reading
voltmeter to switch terminal and to solenoid motor
terminal. With carbon pile in the off position, connect Windings are open circuited.
other battery post to solenoid motor terminal. Quickly
adjust the carbon pile to obtain 5 volts. Ammeter If the fault cannot be repaired and the solenoid
should read 10 to 11.4 amps. performance is questionable, replace the windings.

No Load Test

P63939N

l-Voltmeter 4-Carbon Pile l-Carbon Pile 4-Voltmeter

a--Switch !&Batteries P-Battery S-Jumper Lead
3-Ammeter 3-Ammeter 6-Tachometer

Fig. 3-Solenoid Test Fig. 4-No-Load Test Hook-Up

To prevent overheating, do not energize the pull-in Make connections shown in Fig. 4 (some amme-
winding longer than 15 seconds. Current draw will ters do not require a shunt). Close switch to operate
decrease as the winding temperature increases. starter and adjust carbon pile to obtain specified volt-
age. Compare rpm and current draw with values giv-
Testing Hold-in Windings en below.

Disconnect solenoid. Connect ammeter in series Test Min. Max. Min. Max.
with a switch to switch terminal and to battery. Connect Volts Amps Amps RPM RPM
voltmeter to switch terminal and to solenoid ground
terminal. Connect carbon pile resistor across the bat- 20 60” 80” 5500 7500
tery. Connect other battery post to solenoid ground
terminal. Close the switch and adjust carbon pile to *Includes Solenoid
obtain 20 volts. Ammeter should read 6.1 to 6.8 amps.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0422-4 Starting System TM- 1136 (Apr- 79)

Interpret the test results as follows: 4. Failure to operate with no current draw indi-
cates:
1. Rated current draw and no load speed indicates
normal condition of the starting motor. a. Open field circuit. This can be checked after
disassembly by inspecting internal conditions
2. Low free speed and high current draw indi- and tracing circuit with a test lamp.
cates.
b. Open armature coils. Inspect the commutator
a. Too much friction - tight, dirty, or worn bear- for badly burned bars after disassembly.
ings, bent armature shaft or loose pole shoes
allowing armature to drag. c. Broken brush springs, worn brushes, high insu-
lation between the commutator bars or other
b. Shorted armature. This can be further checked causes which would prevent good contact
on a growler after disassembly. between the brushes and commutator.

c. Grounded armature or fields. Check further af- 5. Low no-load speed and low current draw indi-
ter disassembly. cates:

3. Failure to operate with high current draw indi- a. High internal resistance due to poor connec-
cates: tions, defective leads, dirty commutator and
causes listed under no. 4.
a. A direct ground in the terminal or fields.
6. High free speed and high current draw indicates
b. Frozen bearings (this should have been deter- shorted fields. If shorted fields are suspected, re-
mined by turning the armature by hand). place the field coil assembly and check for improved
performance.

Litho in U.S.A.
JD 750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-75) Starting System 0422-5 _. +;y

REPAIR

11
\

@t
a 13
14\.
w
I
3 A9 51
‘-\
la\* l7 R
19 15
c@L\
)
5

/
/
/

WA ,
-(j---58

59

T41090N

Fig. 5-Starting Motor Assembly

Litho in U.S.A.
 4 Engine JD 750 Crawler Bulldozer
..’ J 0422-6 Startino Svstem TM-1 136 (Nov-75)

l-Terminal Plate Gasket 26-Spring Retainer U-Lock Washer (9 used)

2-Terminal Stud (2 used) 27--Retainer Ring (2 used) 52-Packing (2 used)
3--Machine Screw 28-Nut 53-Commutator End Bushing
4--Solenoid Winding Terminal 29-Field Frame 54-Washer
5-Terminal Insulator 36-Gasket %-Armature
&Terminal Plate (5 used) 31-Plug 56-Pole Shoe (4 used)
7-Packing (2 used) 32-Field Coil 57-Machine Screw (8 used)
8-Insulator (2 used) 33-Terminal Screw 58-Field Coil Insulator (2 used)
g--Washer (2 used) 34-Insulator 59-Gasket
18-Lock Washer (4 used) 35-Washer (2 used) 66-O-Ring
11-Nut (2 used) 36-Nut (2 used) 61-Shift Lever Shaft
12-Nut (2 used) 37-Connector 62-O-Ring
13-Lock Washer 38-Lock Washer 63-Lever Housing
14--Spring 39-Brush Ground. Lead 64-Bushing
15-Contact Disk 46-Brush Pin (2 used) 65-Spacer
16-Lock Clip (2 used) 41-Brush Spring (2 used) 66-Shift Lever
17-Screw (2 used) 42-Brush (4 used) 67-Pipe Plug
18-Sealing Nut (4 used) 43-Special Tapping Screw (4 used) 68-Cap Screw
19-Case And Coil 44-Brush Holder Ground (2 used) 69-Cap Screw (5 used)
28-Cap Screw (4 used) 45-Brush Holder (2 used) 76-Brake Washer
Pl-Plunger 46-Brush Support (2 used) Ti-Cap Screw
22-Washer 47-Commutator End Frame 72-Drive End Bushing
23-Boot 48-Wick (3 used) 73-Drive Housing
24-Spring Retainer 49-Pipe Plug 74-Motor Drive
25-Shift Lever Spring %&Cap Screw (4 used)

Legend for Figure 5

If drive end housing (Fig. 5) is to be removed from To disassemble solenoid linkage remove adjusting
the lever housing, scribe a reference mark across the hole plug, nut, and solenoid plunger assembly. Re-
joint between the two housings for proper assembly. move shift lever shaft and shift lever.

Disconnect field coil connector and remove sole- Motor Drive

noid.
The motor drive is designed to be serviced as a
complete unit, therefore do not disassemble. Replace
NOTE: Scribe a reference mark across the joint
if necessary.
between the commutator end frame and field frame
for proper assembly.

Remove commutator end frame. Remove field

frame from armature and lever housing. Remove
drive end housing.

Pull armature and motor drive from lever housing.

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM-1 136 (Nov-75) Starting System 0422-7

Bushings Soak new wicks in SAE 10 engine oil. Install

wicks, expansion plugs and pipe plugs.

Bushing, Drive Housing

I.D. . . . . . . . . . . . . . . . . . . . 0.625 - 0.627 in.
(15.88 - 15.92 mm)
Wear tolerance. .. .. . . . . . . . . . . . . 0.0636 in.
(1.62 mm)
Oil clearance .. . . . . 0.002 - 0.004 in.
(0.05 - 0.10 mm)
Wear tolerance. . . . . . . . . . . . . . . 0.015 in.
l-Bushing 3-Wick (0.38 mm)
P-Plug
Bushing, Lever Housing
fig. 6-Rebushing Diagram
I.D. . .. ...... .... .0.843 - 0.844 in.
‘(21.41 - 21.44 mm)
Remove pipe plugs, expansion plugs and oil wicks
Wear tolerance. .. ..... . . . . . . . . . . . 0.085 in.
from housings. Press out old bushing. Press new
(2.16 mm)
bushing in to same depth as old bushing.
Oil clearance ........ . . . 0.019 - 0.021 in.
(0.48 - 0.53 mm)
IMPORTANT: Carefully drill bushing through
Wear tolerance. .. .. . . . . . . . . . . 0.027 in.
oil wick hole using same size drill as oil wick
(0.69 mm)
hole, Fig. 6. After drilling, ream bushing to main-
tain proper oil clearance between shaft and bush-
Bushing Commutator End Frame
ing.
I.D. . . ... . . . . . . . . 0.5635 - 0.5645 in.
(14.31 - 14.34 mm)
Wear tolerance. ... .. . . . . . . . . 0.573 in.
(14.55 mm)
Oil clearance . . . . . . . . . . . . . .0.002 - 0.004 in.
(0.05 - 0.10 mm)
Wear tolerance. . . . ............. 0.015 in.
(0.38 mm)

Litho in U.S.A.
 4 Engine JD750 Crawler Bulldozer
0422-8 Starting System TM-l 136 (Nov-Z+.

Armature Inspect brushes. If they are oil soaked or worn re-

place them.
If the commutator is excessively worn, dirty, out of
round, or if it has high insulation, it should be turned
Make sure the brush holders are clean and the
down on a lathe and the insulation undercut l/32
brushes are not binding in the holders. The full brush
inch (0.79 mm) and l/32 inch (0.79 mm) deep.
surface should ride on the commutator to give proper
performance. Check by hand to insure that the brush
The commutator may be cleaned with No. 00
springs are giving firm contact between the brushes
sandpaper. Do not use emery cloth.
and commutator. If the springs are distorted or dis-
colored, they should be replaced.
The armature should be checked for short circuits,
opens and grounds.
Field Coils
1. Short circuits are located by rotating the arma-
ture in a growler with a steel strip such as a Check field coils for shorts and grounds as
hacksaw blade held on the armature. The steel
strip will vibrate on the area of the short circuit.
Shorts between bars are sometimes produced
by brush dust or copper between bars. Under-
cl FBS

Q
directed in FOS, ELECTRICAL SYSTEMS.

qA
cutting the insulation will eliminate these shorts.
IA.1

2. Opens may be located by inspecting the points

.- _ where the conductors are joined to the commu-
tator for loose connections. Poor connections
cause arcing and burning of the commutator. If
the bars are not badly burned, leads originally
soldered to the riser bars can be resoldered.

Then turn down the commutator in a lathe to re-

move the burned material. The insulation should then
be undercut.

l-Brush Lead 4-Carbon Pile Resistor

2-Ammeter SField Terminal
S-Steel Bar 6-24.Volt Power Source

Fig. I-Open-Circuit FMd Winding Check

To check parallel-connected field windings for an

open circuit, make the connections shown in Fig. 7.
Adjust carbon pile resistor to obtain 60 to 75 amps.
Place steel bar against pole shoe. No magnetism in-
dicates an open-circuited field winding. Connect to
other brush lead and check the other field windings.

When replacing sharp coils, use a pole shoe

spreader. Several sharp blows usually allow pole
shoe screws to be turned. Install new field coil insu-
lators (58, Fig. 5).

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-78) Starting System 0422-g

Solenoid Switch Pinion Clearance

The solenoid terminal plate (6, Fig. 5) is removed to
service switch contact assemblies. Always use new
sealing washers and gasket when assembling a sole-
noid.

ASSEMBLY
To assemble starter, reverse the disassembly pro-
cedures (see Fig. 5). Always use new O-ring packings
and gaskets.

Lubricate bearing surfaces with Delco-Remy lubri-

cant No. 1960954.

l-Self-Locking Nut 3-Pinion Clearance

2-Pinion

Fig. B-Checking Pinion Clearance

Connect battery to solenoid switch and ground ter-

minals. Momentarily connect jumper wire between so-
lenoid motor and ground terminals to pull the solenoid
plunger in (Fig. 9) and measure distance between
l-Gasket 4-Shift Lever Shaft pinion and drive housing (3, Fig. 9). Correct pinion
2-Shift Lever 5-Brake Washer clearance is 23/64 -t l/32 in. (9.13 2 0.79 mm). Turn
&Seal Plug
self-locking nut to adjust pinion clearance.
Fig. 8-Lever l-busing
INSTALLATION
Fig. 8 shows gasket and seal plug installed in lever Install starting motor. Connect cables and wiring as
housing. shown in Fig. 2.

To assemble brushes on commutator, pull armature Turn on battery disconnect switch.

out of field frame so that brushes can be placed on
commutator. Then push commutator end frame and
armature in against field frame. Connect field leads to
brush holders.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0422-10 Starting Sysfem TM-l 136 (Nov-78)

JOHN DEERE STARTING MOTOR

GENERAL INFORMATION

l-Plunger 7-Bushing 13-Oil Seal M-Pinion Stop

Z-Shunt Field Terminal &Thrust Washer M-Bushing 2GBushing
3--Solenoid Assembly 9-Commutator G-Felt Pl-Snap Ring
4-Field Connector lo--Field Windings N-Brake Washer 22-Drive End Housing
5-End Frame Cover Ii-Armature 17-Wear Pads 23-Shift Lever
&Brush 12-Pole Shoe 18-Overrunning Clutch

Fig. lo-Sectional view of Starting Motor

The John Deere Starting Motor is located on the The armature is supported on three bushings, one
right side of the engine flywheel housing. each in the drive housing, center bearing housing, and
commutator end frame. The core of the armature con-
The starting motor consists of a drive housing, sists of laminations of thin sheet iron. The outer rims of
overrunning clutch and pinion, drive lever, center laminations are slotted to receive the armature coils.
bearing housing, solenoid switch, armature, yoke and The armature coils are arranged and connected in
field windings, brushes, and commutator end frame. such a way that current flows through all of them at the
same time, thus each coil provides a turning force.

Litho in U.S.A.
JO 750 Crawler Bulldozer Engine 4
TM-l 138 (Nov-78) Starting System 0422-l 1

The field windings are wound on steel pole cores The overrunning clutch is a freewheeling device like
which are affixed to the yoke. They are connected in that of a bicycle permitting it to coast when the pedals
series with armature coils through brushes and com- are not operated. In like manner, the overrunning
mutator segments. clutch transmits power from the armature to the fly-
wheel through the pinion, and it also allows the pinion
The shunt winding is incorporated in the field wind- to overrun and turn faster than the armature after the
tngs and is connected in parallel with the armature. engine has started.

The solenoid switch incorporates two windings-a IMPORTANT: Never run the starting motor more
pull-in winding and a hold-in winding. These are than twenty seconds at a time or overheating will
wrapped around a hollow core. A cylindrical iron result. Allow motor to cool at least two minutes
plunger is placed part of the way in the hollow core. A
contact plate is attached to the plunger, and two
counter contacts are so placed that the plunger move-
ment forces the plate against the contacts. This closes
the circuit between the battery and the starting motor.
At the same time, the plunger movement pushes out
m6
before running it again.

c01 For additional information on starting motors,

refer to “Starting Circuits” in FOS Manual -
ELECTRICAL SYSTEMS.

the overrunning clutch and pinion unit which is linked to

the plunger by means of the drive lever, and the pinion
meshes with the flywheel ring gear.

REMOVAL

Disconnect battery ground strap from crawler.

Open right engine side shield.

Disconnect wires from starting motor.

Remove three cap screws attaching starting motor

to flywheel housing.

Remove starting motor.

NOTE: The JDE-80 Starter Wrench might be nec-

essary to remove the rear attaching cap screw.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0422-l 2 Starting System TM- 1136 (Nov-78)

TESTING AND DIAGNOSIS

Solenoid Tests (Starting Motor Removed) Solenoid Return Test

To prevent damage, solenoid must be on starting
motor when testing the windings. Remove terminal
cover and field coil connector. Disconnect shunt field
winding lead from terminal on field frame. Replace
solenoid if it fails one of the following tests.

Solenoid Pull-in Test

i-24-Volt Source 2-Switch

Fig. 1%Return Test

Make connections shown in Fig. 12. Close the

switch and pull the drive out until the pinion contacts
the pinion stop. When released, the drive should return
without hesitation.
i-24-Volt Source 3-Carbon Pile Resistor
2-Voltmeter 4-Heavy Jumper Wire No Load Test

Fig. 11-Pull-in Tesf

Make connections shown (Fig. 11). With 24 volts

applied, the solenoid should push the pinion out to the
pinion stop when the jumper wire is connected. Re-
move jumper wire. The drive should remain out at
pinion stop. Current through jumper wire will be ap-
proximately 74 amps maximum, so use a heavy jumper
wire and remove it soon after pinion is at stop.

l-24-Volt Source 4-Voltmeter

2-Carbon Pile Resistor !5-Switch
3-Ammeter 6-Tachometer

Fig. 13-No Load Test

Make connections shown in Fig. 13. The starting

motor current draw should be 70 amps maximum at 24
volts. The armature speed should be to 4400 rpm and
higher.

bitho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM-7 136 (Nov-78) Starting System 0422-l 3

No Load Test Diagnosis Low Speed, High Current Draw

Excessive friction.
Fails to Operate, Low Current Draw
Shorted armature.
Open series field circuit. Grounded armature or fields.
Open armature coils.
Defective brush contact with commutator. High Speed, Low Current Draw
Open shunt field circuit.
Fails to Operate, High Current Draw
Grounded terminal or fields. High Speed, High Current Draw
Seized bearings.
Shorted series field coils.
Low Speed, Low Current Draw

High internal resistance.

Defective brush contact with commutator.

REPAIR

Dk iassem bly

l-Pipe Coupling 2-Pinion Stop

l-cover 4-Shunt Winding Lead 3-Pinion
2-Solenoid Assembly CDrive End Housing
3-Field Coil Connector 6-Center Searing Housing Fig. IdRemoving Pinion Stop

Fig. 14-Starting Motor Disassembly

Remove drive end housing (2, Fig. 16). Drive pinion
stop (2, Fig. 15) toward pinion (3) and remove snap
NOTE: Starting motor has metric bolts and nuts
ring (19, Fig. 16) and pinion stop (18). Remove arma-
except for those on the solenoid switch cover (70, Fig.
ture (12) from center bearing housing (8). Remove
16).
overrunning clutch assembly (4), brake washer (17)
and shift lever wear pads.
Disconnect shunt winding lead (4, Fig. 14). Remove
terminal cover, field coil connector (3), and solenoid
Remove shift lever pivot (5, Fig. 16) and shift lever
assembly (2).
(7).
Remove end frame cover (1, Fig. 14), gasket (31,
Fig. 16) brushes (33), commutator end frame assembly
(35) and the brush ground strap (29). Remove field
frame (36).

Litho in U.S.A.
 JD750 Crawler Bulldozer
0422-14 Starting System TM-l 136 (Nov-78)

l-Drive End Bushing 11-Shunt Winding Lead Pl-Field Winding 31-Gasket

P-Drive End Housing 1P-Armature Z-Pole Shoe (4 used) 32-Commutator End
3-Packing 13-Bakelite Washer 23--Square Washer Frame Bushing
4-Dverrunning Clutch 14-Gil Seal 24-Insulating Bushing 33-Brush (4 used)
&-Shift Lever Pivot l-enter Bearing Bushing 25-Square Insulator 34-Brush Spring (4 used)
9-C-Ring x--Oil Felt 26Special Bolt 3!5-Commutator End Frame
7-Shift Lever 17-Brake Washer 27-Field Coil Connector 36-Field Frame
&Center Bearing Housing l&-Pinion Stop 29-Terminal Cover
9-Solenoid Winding 19-Snap Ring 29-Brush Ground Strap
19-Solenoid Switch Cover a&-Shunt Winding Ground 39-End Frame Cover
Screw
fig. 16Btarting Motor

Cleaning Do not immerse the drive end housing, overrunning

clutch, center bearing housing, or commutator end
When cleaning component parts, do not immerse
frame in cleaning solvent. All of these parts have been
the solenoid, field windings or armature in cleaning
prelubricated and solvent will wash this lubricant away.
solvent. Immersing any of these in solvent may dam-
These components should be cleaned in the same
age their insulation. These may be cleaned by wiping
method just mentioned, using a cloth slightly moist-
the parts with a cloth that has been slightly moistened
ened with cleaning solvent and then wiped dry with a
with cleaning solvent and then wiped dry with a clean
clean dry cloth.
dry cloth. -

bitho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM-l 136 (Nov-78) Starting System 0422-l 5

All other parts which are not made of rubber or Armature

nentioned above can be dipped in clean solvent to
Maximum commutator runout is 0.016 inch (0.41
‘emove all oil and dirt.
mm). If necessary, turn commutator and undercut in-
sulation to l/32-inch (0.79 mm). Undercut should
Bushings never be less than 0.008 inch (0.20 mm). Commutator
Install a new oil seal (14, Fig. 16) and a new oil felt O.D. must be 1.77 inches (44.9 mm) or more. Clean
116) saturated with engine oil when replacing center copper dust from between the segments.
oushing.
Check armature for opens, shorts and grounds.
When replacing bushings, press the new bushings
Burned edge of commutator bar indicates an open
n from the chamfered end. Make a bushing driver as
circuit.
shown in Group 0499 or use the following handle and
disks from the D-01044AA Basic Set. Align hole in
Short Circuit Test
commutator and lubrication wick.
Place the armature in a growler and hold a hacksaw
Commutator and Drive End Bushing Tools blade above each slot while slowly rotating the arma-
ture. If a coil is shorted, the blade will be attracted to
Bushing Bushing and repelled from the slot very rapidly resulting in a
Component Removal Installation
growling sound.

Handle 27487 27487

A short circuit most often occurs because of copper
Disk (spacers) 2749 1
dust or filings between two commutator segments. A
27492
short of this nature can be corrected by removal of
Disk 27494 27495
such material.
Disk (pilot) 27493 27493
Ground Circuit Test
Center Bushing Tools

Component Bushing Oil Seal

Handle 27487 27487

Disk 27605 27512
Disk (pilot) 27501 27501

Commutator and Drive End Bushing

Specifications*

I.D. of bushing . ..... . . . 0.6693 to 0.6704 in.

(17.00 to 17.03 mm)
Oil clearance.. . . . . . . . , . 0.0036 to 0.0070 in.
(0.09 to 0.18 mm)
Fig 17-Armature Ground Test
Maximum clearance . . . . . .0.016 in. (0.41 mm)
Bushing depth.. . . . . . . . 0.008 to 0.022 in.
(0.20 to 0.56 mm)

*Reaming may be necessary after installation.

Center Bushing Specifications

I.D. of bushing ... ......... . 1.182 to 1.184 in.

(30.02 to 30.07 mm)
Maximum clearance .. . .. 0.0236 in. (0.60 mm)
Bushing depth.. . . . . 0.017 to 0.032 in.
(0.43 to 0.81 mm)

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0422-l 6 Starting System TM- 1136 (Nov-78)

With the ohmmeter set to read on its highest scale, Overrunning Clutch and Pinion
place one test lead on the commutator and the other
Do not immerse the overrunning clutch and pinion in
lead on the armature core or shaft (Fig. 17). If the test
a cleaning solvent. The unit has been pre-lubricated
meter indicator swings towards zero, the armature is
and solvent will wash lubricant away. It may be cleaned
grounded. Replace armature.
with a cloth moistened with a cleaning solvent and
wiped dry.
Open Circuit Test

Rotate the pinion. Pinion gear should rotate

smoothly (but not necessarily easily) in one direction,
and should not rotate in the opposite direction.

If the pinion gear does not rotate smoothly, or if it is

worn, chipped, or burred, it should be replaced.

Field Windings and Shunt Windings

Ground Circuit Test

Fig. l&Open Circuit Test

With the ohmmeter set to read on its lowest scale,

place one test lead on the commutator segment and
the other test lead on an adjacent segment (Fig. 18).
Repeat this operation for all G<ments bymoving one
lead at a time. If the test meter indicator does not swing
to zero and remains stationary, the armature coil-be--
tween these two segments is open. Replace armature.

Burned commutator segments are usually an indi-

cation of an open circuited coil.

Fig. ZO-Ground Test

Remove the screw and hang the eyelet terminal in

the air. Using an ohmmeter set to read on its highest
scale, place one test lead on the copper terminal bolt
and the other lead on a clean spot of the field frame
Fig, 1g-checking Armature Runout (Fig. 20). If the ohmmeter dial indicator swings toward
zero, a grounded circuit is indicated. Replace the field
Place armature in V-blocks and check for a bent windings.
shaft as shown in Fig. 19. Replace armature if shaft
runout exceeds specification. Runout should not ex-
ceed 0.006 inch (0.15 mm).

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Now78) Starting System 0422-17

Open Circuit Test To check the field windings for an open circuit set
the ohmmeter to read on its lowest scale and place one
test lead on the copper terminal bolt and the other lead
on the bare field end (Fig. 22). If the ohmmeter dial
indicator does not swing to zero, the field windings are
open-circuited. Replace the field windings.

Before removing pole shoes, scribe a mark on the

pole shoe and the field frame to be sure they will be
assembled in their original position. Tighten pole shoe
screws with 30 lb-ft (41 Nm) (4 kg-m).

Brushes
Replace brushes if they are oil soaked or if they are
worn shorter than 5/8 inch (15.9 mm). Check brush
insulated holders for grounds.
Fig. Pl-Shunt Winding Open Circuit Test

To check the shunt windings, set the ohmmeter to

read on its lowest scale. Place one test lead on the
terminal bolt and the other lead on the eyelet terminal
(Fig. 21). If the ohmmeter does not swing to zero, it is
open circuited and the field winding assembly will have
to be replaced.

Fig. 2343rush Holder insulation Test

With the ohmmeter set to its highest reading scale,

connect one test lead onto the commutator end frame
and the other lead to the brush holder Fig. 23. If the dial
indicator swings toward zero, the positive brush holder
is grounded and should be replaced.

Fig. 22-Field Winding Open Circuit Test

Litho in U.S.A.
_-
4 Engine JD750 Crawler Bulldozer
0422-18 Starting System TM-I 136 (Nov-78)

IMPORTANT: Solenoid contacts and plunger

will be damaged if current is applied to solenoid
when it is removed from starting motor.

Remove nuts from solenoid “S” terminal and pull-in

terminal. Then remove switch cover (3, Fig. 25).

When installing switch cover (3), place “S” terminal

gaskets on winding terminal, align main contact verti-
cally, and place packing (2) on switch cover.

Assembly
To assemble the starting motor, reverse the disas-
sembly procedures, Use new seals and packings.

Lubricate the shift lever, overrunning clutch, thrust

washers, bushings, and armature bearing surfaces
with John Deere Multi-Purpose Lubricant,

If the shift lever was removed, tighten the shift lever

pivot screw with 30 lb-ft (41 Nm) (4 kg-m). Bend
Fig. 24-Measuring Brush Spring Tension
washered edge of screw down to prevent loosening.

Measure the brush spring tension with a spring

Tighten center bearing housing to field frame bolts
scale. The brush spring tension should be a mimimum
with 6 lb-ft (8 Nm) (0.8 kg-m). Tighten drive end and
of 40 ounces (11 N) (1 kg), as the spring just leaves the
commutator end frame bolts with 10 lb-ft (14 Nm) (1
brush holder. When taking the reading, the scale
kg-m).
should be on.a line parallel with the edge of the brush
holder.

Solenoid

l-Brush 3-Brush Spring

2-Brush Leads

l-Solenoid Windings 7-Plunger Return Spring Fig. 26-Brush installation

2-Packing 8-Contact Plate Spring
3-Switch Cover O-Insulator Bushing
When installing the brushes, twist brush leads 180
4-Cover Screws 1 O-Contact Plate
5-Plunger Cover 1 l-Castellated Nut
degrees (Fig. 26). Press the leads of the insulated
GPlunger brush down against the brush.

Fig. 25-Solenoid

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-78) Starting System 0422-19

Connect a 24-volt source with a reserve capacity

rating of 360 minutes, rheostat, ammeter, control
switch, voltmeter, and tachometer to starting motor as
shown in Fig. 28.

Starting motor should rotate smoothly at a constant

speed of at least 4400 rpm at 24 volts with a maximum
current draw of 70 amperes.

INSTALLATION

I-Pinion Stop 3-Washer (Remove After

2-Retaining Ring Using)

fig. 27-hstalling Pinion Stop

Slide pinion stop onto shaft, with open side toward

end of shaft. Install retaining ring in groove. Force
pinion stop over ring, using a washer and two pairs of
pliers as shown in Fig. 27. Remove washer.

Give the assembled motor a no-load test. Solenoid

action during the test should be satisfactory.

No Load Test (After Assembly) l-Positive Battery 3-Starting Motor

Cable ASolenoid
24iolenoid to Starting 5-Solenoid to Starting
Circuit Relay Circuit Relay

Fig. 29-Solenoid Wire Connections

Install starting motor and secure to flywheel housing

with cap screws.

Connect wires to starting motor.

Close engine side shield and connect battery ground

strap or turn on battery disconnect.

134507N

1-24 Volt Source !+Voftmeter

2--Rheostat 6-Starting Motor
3-Ammeter 7-Tachometer
4-Control Switch

Fig. 28-No Load Test (After Assembly)

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0422-20 Starting System TM-1 136 (Nov-78)

Litho in U.S.A.
JO750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-78) Fan Drive 0429-l

Group 0429
FAN DRIVE
GENERAL INFORMATION REMOVAL
The fan is driven by the crankshaft through pulleys Disconnect negative ground strap from battery or
snd V-belts. Correct belt tension is maintained by an turn battery disconnect switch to “OFF.”
dler pulley and idler pulley support.

T42905

l-Pipe Spacer (2 used) 1 l-Sleeve 2O-Crankshaft Damper

2-idler Pulley Bracket 12-idler Pulley 21-Gap Screw
S-Lock Washer (4 used) 13-Bali Searing (2 used) 22-Special Washer
4-tap Screw M-Special Washer 23-Crankshaft Pulley
Cxternal-Tooth Lock Washer %-Snap Ring 24-Woodruff Key
&Cap Screw l&Washer (2 used) 25-Gap Screw
7-tap Screw 17-tap screw (2 used) 2Mdler Pulley Support
8-Fan Belt (Matched Set) l&-cap screw (4 used) 27-Pipe Spacer
g--Plug 1GSpecial Washer (4 used) P&Jam Nut
lo-Special Screw

Fig. l-Fan Drive

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0429-2 Fan Drive TM- 1136 (Now-78)

Loosen jan nut (28, Fig. 1) and release tension by INSTALLATION

turning cap screw (25) counterclockwise.
Install bearings (13), special washer (14), snap ring
(15) and sleeve (11) in idler pulley.
Remove hardware attaching the idler pulley support
(26) to the idler pulley bracket (2).
Install idler pulley assembly on idler pulley support
(26). Tighten special screw (10) to 55 lb-ft (75 Nm) (8
Remove plug (9). Remove special screw (10) from
kg-m) torque.
idler pulley support.
Install plug (9) in idler pulley.
Remove sleeve (1 l), snap ring (15), special washer
(14) and bearings (13) from idler pulley (12).
Install idler pulley support with idler pulley assembly
on idler pulley bracket.
REPAIR
Inspect bearings for damage and replace as neces- Position fan belts on idler pulley and adjust fan belts
sary. as shown in Group 9010.

If the plug was damaged during disassembly, re-

place with a new one.

Litho in U.S.A.
JO750 Crawler Bulldozer Engine 4i
TM- 1136 (Apr- 79) Flywheel, Housing and Fasteners 0433-l”

Group 0433
FLYWHEEL, HOUSING AND FASTENERS
GENERAL INFORMATION Remove pressure plate and driven disk from fly-
wheel (Group 0370).
The flywheel and flywheel housing are located at the

A
rear of the engine. CAUTION: Flywheel is heavy. Plan proper
handling procedure to avoid injuries.
A driven disk and pressure plate are attached to the
flywheel and the clutch housing is attached to the Remove two flywheel attaching cap screws and
flywheel housing.
install two pilot studs in their place.

A 129 tooth ring gear for the starting motor is shrunk Remove the remaining flywheel attaching cap
in place on the front outer rim of the flywheel. On the
screws.
front face of the flywheel is a “TDC” (top dead center)
bore which is used when timing injection pump and
Remove the flywheel.
adjusting valve tappets.

REMOVAL
To service the flywheel, it is necessary to remove
engine from the crawler (see Group 0400).

Remove splitter housing and clutch housing.

Remove flywheel housing from engine.

4

T56765F
l-Special Cap Screw (4 used) 6-Lock Washer (8 used) KG-Tachometer Drive Pinion
-413473) 7-Flywheel Housing 14-Spedal Washer
(
Cap Screw (4 used) (413474- ) &Gasket 15-Adapter
~-&III Searing g-O-Ring 1Casket
3-Flywheel Ring Gear lo-Plug with O-Ring 17-&p
4-Flywheel ll-special Screw l&Pipe Plug (242751- )
+-Cap Screw (8 used) 12-Gap Screw (4 used) 19-Special Washer (4 used)

Fig. l-Flywheel and Housing

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0433-2 Flywheel, Housing and Fasteners TM- 1136 (Apr- 79)

REPAIR INSTALLATION
Inspect the clutch face of the flywheel for scoring, Install pilot bearing, driven disk and pressure plate
overheating, or cracks. Replace a defective flywheel. as described in Group 0370.

Examine starter gear for worn or broken teeth. Position flywheel on pilot studs and install new at-
taching cap screws.
Remove damaged ring gear.
IMPORTANT: Torque “D” grade cap screws to

a CAUTION: Oil fumes or oil can ignite

above 380°F (193°C). Use a thermometer
and do not exceed 360°F (182°C). Do not allow a
85 lb-ft (115 Nm) (12 kg-m). Torque “F” grade cap
screws to 120 lb-ft (163 Nm) (17 kg-m). DO NOT mix
“D” grade and “F” grade cap screws.
flame or heating element to be in direct contact
with the oil. Heat the oil in a well-ventilated area. Tighten flywheel housing to block 3/8-inch cap
Plan a safe handling procedure to avoid burns. screws to 35 lb-ft (47 Nm) (5 kg-m) and 5/8-inch cap
screws to 170 lb-ft (230 Nm) (24 kg-m).
Heat new ring gear evenly in oil (to 360°F [182X]
maximum) or in oven (to 450°F 1232”Cl maximum) and Apply T43514 John Deere Loctite Plastic Gasket or
install hot, with ring gear tooth chamfer toward engine equivalent to finished surface of clutch housing before
side of flywheel. Drive ring gear onto flywheel until it joining to engine.
bottoms all the way around on flywheel shoulder.
Join clutch housing and splitter housing to engine.
For repair and assembly of the pressure plate, driv-
en disk and pilot bearing,- refer to Group 6370. Refer to Group 0400 and install engine, clutch
housing and splitter housing as a unit.

Connect drive shafts to drive hub.

IMPORTANT: If tractor is operated in 36 in. (914

mm) or more mud or water, install l/2-inch pipe
plug (18, Fig. 1) in flywheel housing. Remove the
pipe plug while operating tractor in other condi-
tions.

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 JD750 Crawler Bulldozer Engine 4
TM- 1136 (Apr- 79) Specifications and Special Tools 0499-l

Group 0499
SPECIFICATIONS AND SPECIAL TOOLS
ENGINE BREAK-IN
SPECIFICATIONS AND TORQUE VALUES

NOTE: Whenever possible, use a dynamometer to provide a more accurate break-in, assuring proper initial
seating of new piston rings.

Remarks

I Check oil 1

1900 to 2200 rpm

1 pressure,

coolant

temperature,

and leakage.
A
q
Field Only
I I I
*Loads can be simulated in the field by controlled machine operation.

**After this run, loosen cylinder head bolts 5 to 70 degrees; then retighten bolts one at a time, in sequence, to 95
lb-ft (129 Nm) (13 kg-m). Check and reset valve clearance.

+After break-in, drain crankcase oil and remove filter. Install new filter and fill crankcase with oil of proper vis-
cosity and service classification.

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4 Engine JD750 Crawler Bulldozer
0499-2 Specifications and Special Tools TM- 1136 (Apr- 79)

CRANKSHAFT AND MAIN BEARINGS

SPECIFICATIONS AND TORQUE VALUES-Continued
1 - Flywheel to crankshaft cap screw
torque. . . .... .. ... . . 85 lb-ft
(115 Nm) (12 kg-m)
2 - Crankshaft rear oil seal to housing
runout. . . .. .. . . .0.0060 in.
(0.152 mm)
3 - O.D. main bearing journal . 3.123 to 3.124 in.
(79.32 to 79.35 mm)
Round within. ... . . . . . . .0.0030 in.
P32803N
(0.076 mm)
Fig. I-Crankshaft Assembly 4 - Crankshaft end play . . . . 0.0020 to 0.0080 in.
(0.051 to 0.203 mm)
Maximum end play . . . . . . . . . . . .0.0150 in.
(0.381 mm)
5 - Fan pulley to crankshaft cap screw
torque. . .. . . ... .. .. 85 lb-ft
(115 Nm) (12 kg-m)
6 - O.D. of connecting rod
journal . . . . . . . . . . 3.0630 to 3.0640 in.
(77.70 to 77.83 mm)
Round within. . . . _. . . . . . . . .0.0030 in.
(0.076 mm)
7 - Main bearing I.D.
(assembled) . . . . 3.1256 to 3.1276 in.
(79.391 to 79.441 mm)
Main bearing to journal
clearance.. . . . .... 0.0016 to 0.0046 in.
(0.041 to 0.117 mm)
Maximum clearance ... . . . .0.0060 in.
(0.152 mm)
Journal taper per inch of journal
length . . . . . . . . . . . . . . . . . . .O.OOl in.
(0.025 mm)
Journal out-of-round . . . ... .0.0030 in.
(0.076 mm)
Main bearing undersize inserts
available.. 0.002, 0.010, 0.020 and 0.030 in.
(0.05, 0.25, 0.51 and 0.76 mm)
8 - Main bearing caps to block
cap screw torque. .... . . . . 85 lb-ft
(115 Nm) (12 kg-m)
Rear crankshaft oil seal below machines
surface of seal bore . . 0.145 to 0.155 in.
(3.70 to 3.94 mm)
Rear crankshaft wear ring from rear
face of crankshaft . . . . . . . 0.307 to 0.317 in.
(7.80 to 8.05 mm)

Litho in U.S.A.
JO750 Crawler Bulldozer Engine 4
TM- 1136 (Nov- 75) Specifications and Special Tools 0499-3

CAMSHAFT AND VALVE ACTUATING MEANS

+ .“r. SPECIFICATIONS AND TORQUE VALUES ,
,
1 - O.D. of idler shaft. . . . . . .$.7495 to 1.7505 in.
(44.437,to t4.463 mm)
2 - Idler shaft end play . . . . .O,OOlO to O.OqO in.
(0.025 to 0.118 mm)
3 - I.D. idler bushing. . . . . . . 1.7520 to 1.7530 in.
(44.501 to 44.525 mm)
Oil clearance between
shaft and bushing . . .0.0015 to 0.0035 in.
(0.038 to 0.089 mm)
Maximum oil clearance . . . . . . . . . . 0.0060 in.
(0.152 mm)
4 - Crankshaft upper idler gear
cap screw torque . . . . . . . . . . . . . .65 lb-ft
Fig. Z-Upper and Lower idler Gears (88 Nm) (9 kg/m)
5 - Width of idler gears at
hub . . . . . . . . . . .0.8650 to 0.8670 in.
(21.971 to 22.022 mm)
6 - Crankshaft lower idler gear
cap screw torque .... ...... . . .95 lb-ft
(129 Nm) (13 kg/m)
7 - Width of idler gear
shaft . . . . .. . .0.8680 to 0.8720 in.
(22.047 to 22.149 mm)

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4 Engine JD750 Crawler Bulldozer
0499-4 Specifications and Special Tools TM-I 136 (Nov-75)

CAMSHAFT AND VALVE ACTUATING MEANS

SPECIFICATIONS AND TORQUE VALUES-Continued
1 - Camshaft gear to upper
idler.. . . . 0.0028 to 0.0135 inch
(0.071 to 0.343 mm)
2- Injection pump gear to upper
idler. . . . . . . 0.0028 to 0.0135 inch
(0.071 to 0.343 mm)
3- Crankshaft gear to upper
idler. . . . . _. 0.0028 to 0.0315 inch
(0.071 to 0.343 mm)
4- Crankshaft gear to lower
idler.. . . . .. 0.0027 to 0.0137 inch
(0.069 to 0.348 mm)
5 - Oil pump gear to lower
idler. . . . . . . . . . . . . 0.0027 to 0.0137 inch
(0.069 to 0.348 mm)

Fig, 3-Gear Train

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-0
 G

JD750,Ctawler Bulldozer Engine 4

TM-1 136 (Nov-75) Specifications and Special Tools 0499-5

CAMSHAFT AND VALVE ACTUATING MEANS

SPECIFICATIONS AND TORQUE VALUES-Continued
1 - O.D. of rocker arm shaft .0.7869 to 0.7879 in.
(19.987 to 20.013 mm)
Additional wear tolerance . . . . . . 0.0020 in.
(0.051 mm)
@ I---’ 2 - Rocker arm shaft clamp to head
+@ &d cap screw torque . . . . . . . . . . . . . . .35 lb-ft
I (47 Nm) (5 kg/m)
,
I
I
I
I
I
I
!
I
I
/I
T42764N @@@a-,. .!

Fig. 4-Rocker Arm Shaft and Clamp

1 - I.D. of rocker arm bore. . .0.7900 to 0.7920 in.
(20.066 to 20.117 mm) :2;
Additional wear tolerance . . . 0.0020 in. ,
(0.051 mm) 0

T34724N

Fig. 5-Rocker Arm

Lifho in U.S.A.
 :
4; Engine JO750 Crawler Bulldozer
0499-6 Specifications and Special Tools TM- 1136 (Nov- 75)

CAMSHAFT AND VALVE ACTUATING MEANS

.SPECIFICATIONS AND TORQUE VALUES-Continued
1 - Rocker arm cover to cylinder head
cap screw torque ... . .. 25 lb-in
(2.8 k;)’ iO.29 kg/m)

Fig. 6-Rocker Arm Cover

1 - O.D. of camshaft
journal . . . . . I . , .2.1997 to 2.2007 in.
(55.773 to 55.878 mm)
Camshaft journal
clearance .. . . . . . . .0.0035 to 0.0055 in.
(0.089 to 0.140 mm)
Maximum allowable clearance . . . 0.0090 in.
(0.229 mm)
2 - Camshaft end play . . . .0.0025 to 0.0085 in.
(0.064 to 0.216 mm)
Maximum end play. . . . . . . . . . 0.0150 in.
(0.381 mm)

3 - Camshaft thrust plate to block

cap screw torque . . . . . . . . . . . .35 lb-ft
(47 Nm) (5 kg/m)

4 - Thrust plate thickness . .1.1560 to 0.1580 in.

(3.988 to 4.013 mm)
Minimum thickness .. . .. . 0.1510 in.
(2.821 mm)

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JD 750 Cr&vler Bulldozer Engine 4
TM- 1136 (Nov-75) Specifications and Special Tools 0499-7

CAMSHAFT AND VALVE ACTUATING MEANS

SPECIFICATIONS AND TORQUE VALUES-Continued

1 - Distance of front oil seal from front of timing

gear cover. . 0.33 in.
(8.3 mm)

l’27591N

Fig. &Front Oil Seal Installed in

Timing Gear Cover

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4 Engine JD750 Crawler Bulldozer
0499-8 Specifications and Special Tools TM-l 136 (Nov-75)

CONNECTING RODS AND PISTONS

SPECIFICATIONS AND TORQUE VALUES

1 - I.D. of piston pin bushing

in rod . . . . . . . 1.6260 to 1.6270 in.
(41.300 to 41.328 mm)
Piston pin to connecting rod bushing
clearance . . . . . .0.0008 to 0.0022 in.
(0.018 to 0.053 mm)

2 - I.D. connecting rod bearing

(assembled) . . . .3.0656 to 3.0676 in.
(77.866 to 77.917 mm)
Connecting rod bearing to journal
clearance.. . . . . . . .0.0016 to 0.0046 in.
(0.041 to 0.117 mm)
Connecting rod undersize bearing inserts
available. .. 0.002, 0.010, 0.020 and 0.030
(0.05, 0.25, 0.51 and 0.76 mm)
a
3 - Connecting rod cap to rod cap
screw torque. . . . 90 to:? d0 lb-ft
(122 to 136 Nm) (12 to 14 kg/m)

Fig. B-Connecting Rod

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 Engine 4
JD750 Crawler Bulldozer
Specifications and Special Tools 0499-g
TM- I 136 (Apr- 79)
)

CYLINDER BLOCK
SPECIFICATIONS AND TORQUE VALUES I

1 - Liner height above block 0.001 to 0.004 in.

(0.02 to 0.10 mm)

Piston to cylinder liner clearance at

bottom of skirt (max.) . . . 0.008 in.
(0.20 mm)
Liner out-of-roundness (max.) .. .0.0020 in.
(0.05 mm)
Liner taper (max.) . . . .0.0020 in.
(0.05 mm)

Fig, IO-Liner and Bock

Piston cooling orifices in main bearing web

torque . . .. .85 to 110 lb-in.
(9.6 to 12.4 Nm) (0.98 to 1.27 kg-m)

Fig. 11-Piston Cooling ofifice

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 4 Engine JD750 Crawler Bulldozer
0499-10 Specifications and Special Tools TM- 1136 (Apr-79)

ENGINE OILING SYSTEM

SPECIFICATIONS AND TORQUE VALUES

1 - Oil pressure regulating valve spring

compressed at 32.5 to 38.5 lb.
(145 to 171 N) (15 to 17 kg). . 1.91 in.
(48.5 mm)

T34726
Fig. 12-O;/ Pressure Regulating Spring
1 - Oil pan to block cap screw torque. . . 35 lb-ft
(47 Nm) (5 kg-m)

244263N

Fig. 13-Oil Pan 1 - Oil pump to block

cap screw torque. . . . . . . . . .35 to 45 lb-ft
(47 to 61 Nm) (5 to 6 kg-m)
2 - I.D. of gear bore
in housing . . . . . . . . . 1.5340 to 1.5350 in.
(38.964 to 38.989 mm)
3 - Thickness of gears . . _. 2.0070 to 2.0090 in.
(50.978 to 51.029 mm)
4 - Oil pump gear nut torque . . . . . 35 lb-ft
(47 Nm) (5 kg-m)
5 - O.D. of gears . _. . _. _. 1.5290 to 1.5310 in.
(38.837 to 38.887 mm)
6 - Gear bore depth
in housing . . . _. . . . 2.0105 to 2.0135 in.
Fig. 14-Engine Oil Pump (51.067 to 51.143 mm)

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JD750 Crawler Bulldozer Engine 4
TM- 1136 (Mar-78) Specifications and Special Tools 0499-11

CYLINDER HEAD AND VALVES

SPECIFICATIONS AND TORQUE VALUES
1 - Angle of valve seat ..... Intake - 30”
Exhaust - 45”

2 - Width of valve seat . . . .0.0830 to 0.0930 in.

(2.108 to 2.362 mm)

Distance closed valve to head deck

(a) intake.. . . . . . . . . .0.023 to 0.046 in.
(0.58 to 1.19 mm)
(b) exhaust.. . . . . . . . . .0.038 to 0.072 in.
(0.97 to 1.85 mm)

I.D. of valve guide . . . . .0.3745 to 0.3755 in.

(9.512 to 9.538 mm)
Valve stem to guide
clearance . . . .0.0020 to 0.0040 in.
(0.051 to 0.102 mm)
Wear tolerance . . 0.0020 in.
(0.051 mm)

Fig. 15-Head, Seat and Guide

1 - Angle of valve face
(a) intake..............................29.5”
(b) exhaust. . . . . . . . . . . . , . . 44.5”

2 - O.D. of valve head

(a) intake.. . . . . . . . . . . .1.8160 to 1.8260 in.
(46.126 to 46.380 mm)
(b) exhaust.. .. . . . . . .1.5700 to 1.5800 in.
(39.878 to 40.132 mm)

3 - O.D. of valve stem.. . . .0.3715 to 0.3725 in.

(9.436 to 9.462 mm)

Oversize valves
available. . . . . . . . .0.003, 0.015 and 0.030 in.
(0.08, 0.38 and 0.76 mm)

T328OON
Fig. 16-Valve

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4 Engine JD750 Crawler Bulldozer
0499-12 Specifications and Special Tools TM- 1136 (Mar-78)

CYLINDER HEAD AND VALVES

SPECIFICATIONS AND TORQUE VALUES-Continued
Valve clearance
(a) exhaust.. . ... . . . . . . . ~. 0.018 in.
(0.46 mm)
(b) intake.. . .. . .. . . . . . . . . . 0.014 in.
(0.35 mm)

Valve spring length (valve open at 131 to

152 lb. (583 to 676 N)
(59 to 69 kg) . ~ . . . . . . . . . . . . . . . 1.36 in.
(34.5 mm)

Valve spring length (valve closed) at 54 to

62 lb. (240 to 276 N)
(24 to 28 kg). . . . . . . . . . . . . . . . . . .1.81 in.
(46.0 mm)
Valve spring free length . . . . . . . . . . . .2.12 in.
(53.8 mm)

Valve lift
(a) exhaust . . . . . . . . . . . . .0.456 to 0.482 in.
(11.58 to 12.24 mm)
(b) intake. . . . . . . . . . . . . . .0.460 to 0.490 in.
Fig, 17-Valve Spring and Rocker Arm (11.68 to 12.45 mm)

Rocker arm cover to cylinder head

cap screw torque . . . . . . . . . . . . . . 25 lb-in.
(2.8 Nm) (0.29 kg-m)

Cylinder head to block

cap screw torque . . . , . . . . . . . . . . . . . 95 lb-ft
(129 Nm) (13 kg-m)

After 30 minutes run at 3/4 full load, loosen one

bolt 5 to IO degrees and retighten to 95 lb-ft (129
Nm) (13 kg-m), repeat for each bolt.
T42725N
Fig. 1d-cylinder Head Maximum amount of material to be removed
from bottom of head . . . . . . . . . . . . . .0.030 in.
(0.76 mm)

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JD750 Crawler Bulldozer Engine 4
TM- I 136 (Apr- 79) Specifications and Special Tools 9499-l 3

FUEL INJECTION SYSTEM

SPECIFICATIONS AND TORQUE VALUES

Fig 194njectionPump and No.?zles(C -2834711 Shown)

1 - Injection nozzle inlet torque.. . . . . . , , . . . 35 lb-ft 5 - Timing hole cover screw

(47 Nm) (5 kg-m) torque . . . . . . . . . . 15 to 20 lb-in (1.7 to 2.3 Nm)
(0.17 to 0.23 kg-m)
2 - injection line connector screw
torque.. . . . . . . . . . . . . . . . . . . . . . . . . . . 35 lb-ft 6 - Fuel inlet screw torque.. . . . . . . . . . . . . 20 lb-ft
(47 Nm) (5 kg-m) (27 Nm) (3 kg-m)

3 - Drive hub nut torque.. . . . . . . . 140 to 150 lb-ft 7 - Injection nozzle hold-down cap screw
(190 to 203 Nm) (19 to 21 kg-m) torque.. . . . . . . . . . . . . . . . . . . . . . . . . 30 lb-ft
(27 Nm) (3 kg-m)
4 - Mounting bolt nut torque . . . . . . . . . . . . . . 20lb-ft
(27 Nm) (3 kg-m)

1 - Leak-off nut torque . . . . . . . . . . 25 to 35 lb-in

(2.8 to 4.0 Nm) (0.29 to 0.40 kg-m)

Fig. 19A-Leak-off Nut

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4 Engine JD750 Crawler Bulldozer
0499-14 Specifications and Special Toots TM- 1736 (Apr- 79)

FUEL INJECTION SYSTEM

SPECIFICATIONS AND TORQUE VALUES-Continued
Test Stand (Fuel Injection Pump)
Model Number . . . . . . . . . DM4627MD2916
Part Number . . . . . . . . . . . . . . . . AR73505
Roller-to-roller distance . . . . 1.963 -+ 0.0015 in.
(49.86 ?- 0.038 mm)
Governor linkage gap . . . . . . . 0.125 to 0.165 in.
(3.18 to 4.19 mm)

NOTE: In order to obtain proper test results, do the

following:

Use 0.25 in. (6.35 mm) O.D. by 0.093 in. (0.69 mm)
I.D. by 20 in. (508 mm) long test lines.

Use 12SD12 Robert Bosch Calibrating Nozzles,

2500 psi (172 bar) (176 kg/cm*) opening pressure.
Use JDF-2 Test Oil or equivalent (34 to 36 SUS I
rating per SAE J967A with oil at 100°F [38”Cl).

Test oil should be 110 to 115°F (43 to 46°C).

Operate pump clockwise (viewed from drive end) at

500 rpm wide open throttle for 10 minutes prior to
test.

NOTE: Pump operates at l/2 engine rpm. Rpm’s

given are test stand rpm unless otherwise noted.

Electric shut-off connected to 24 volt power source

external of test stand.

Pump is timed to cylinder marked “X”.

Transfer pump vacuum

Head End
(200 rpm). . . , . . . . . . . . 18 in. (457.2 mm) Hg. min.
T47267N Transfer pump pressure
(1050 rpm)
Fig. 798~Rotation and Timing
Volume. . . . . . . ~. . . . . . . 80 to 84 cc/1000 strokes
Maximum variation between
cylinders . . . . . . . . . . . 5 cc/1000 strokes
Transfer pump pressure. . . . . . . . .78 to 88 psi
(5 to 6 bar) (5 to 6 kg/cm*)

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JO 750 Crawler Bulldozer Engine 4
TM- 1136 (NOW78) Specific&ions and Special Tools 0499-l 5

FUEL INJECTION SYSTEM

SPECIFICATIONS AND TORQUE VALUES-Continued

Test Stand (Fuel Injection Pump)-

Continued

Minimum cranking speed delivery (75 rpm)

Volume . . . 40 cc/1000 strokes min.
Transfer pump pressure . . . 12 psi min.
(1 bar) (1 kg/cm*)

Automatic speed advance

RPM Cam Movement

300 to 500 ....................... .l”

750 to 850 ...................... ..5”
by 950 ........................... .6” 2 l/2”

Fuel delivery (1050 rpm)

Volume .. .
Maximum variation
.tlu to 84 cc/l 000 strokes
1
q 1

between cylinders. . 5 cc/1000 strokes

Fuel delivery (750 rpm)

Volume ... . .84 to 88 cc/l 000 strokes
Maximum variation between
cylinders . . . . 7 cc/l 000 strokes

High idle (WOT) (1165 rpm)

Volume . . . .lO to 12 cc/1000 strokes
Maximum variation between
cylinders . . . . . . 4 cc/1000 strokes

Governor cut-off (1190 rpm) .

Volume . . .5 cc maxIlO strokes

Low idle (400 rpm)

Volume _. . . . .lO to 12 cc/1000 strokes
Maximum variation between
cylinders . . . . . 4 cc/1000 strokes

Return oil (1050 rpm) . . .100/400 cc min. 1

Check shut-off at (200 rpm)

Volume . . . . . .2 cc max/lOOO strokes

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 4 Engine JD750 Crawler Bulldozer
‘049(c1;76 Specifications and Special Tools TM-1 136 (Nov-78)

FUEL INJECTION SYSTEM

SPECIFICATIONS AND TORQUE VALUES-Continued

Test Stand (Fuel Injection Nozzles)

GENERAL INFORMATION
Number of orifices . . . .. . .. . . 4
Orifice diameter. . . 0.012 in. (0.305 mm)
Sac hole diameter. . 0.042 in. (1.067 mm)
Hole length (sac wall) . 0.021 in. (0.533 mm)

Nozzle settings
Nozzle opening
pressure (new). . . . . 3150 to 3250 psi
(217 to 224 bar) (221 to 228 kg/cm2)
Nozzle opening
pressure (used) . . . . . . . . 2950 to 3050 psi
(203 to 210 bar) (207 to 214 kg/cm’)
Maximum opening
pressure difference
between cylinders . .... . . . 100 psi
(7 bar) (7 kg/cm2)
Nozzle valve lift. . . . . . .3/4 turn from bottom
(0.0135 in. lo.343 mm])
nominal
Pressure adjusting screw-
to-nozzle body torque . . . .70 to 80 lb-in.
(7.9 to 9.0 Nm) (0.8 to 0.9 kg/m)
Lift adjusting lock
nut torque. . . . . . . . . . . . .35 to 45 lb-in.
(4.0 to 5.1 Nm) (0.40 to 0.52 kg/m)

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 t- ‘
JO750 Cra wier Bulldozer Engine 4
TM- 1136 (Feb-77) Specifications and Special Tools 0499-17

TURBOCHARGER
SPEClFlCATlONk AND TORQUE VALUES

1 - Radial bearing movement. . . . . . 0.003 in.

(0.08 mm) to 0.006 in. (0.15 mm)
2 - Rotating assembly axial end
play.. . . . . . . . . . . . . . . . . 0.001 in. (0.03 mm)
to 0.004 in. (0.10 mm)
3 - Impeller nut torque . . . . . . . . . . . .18 to 20 lb-in
(2.0 to 2.3 Nm)
(0.21 to 0.23 kg/m)
4- Lock plate bolts torque . . . . . .40 to 60 lb-in
(4.5 to 6.8 Nm)
(0.46 to 0.69 kg/m)
5 _ Turbo housing to center housing nut
torque . . . . . . . . . . . . . . . . . 100-l 30 lb-in
(11.3 to 14.7 Nm)
(1.15 to 1.50 kg/m)

Fig. PO-Turbocharger

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 .

4 ” Engine JD750 Crawler Bulldozer

0499-18 Specifications and Special Tools TM- 1136 (Feb-77)

WATER PUMP
SPECIFICATIONS AND TORQUE VALUES

1 - Rear seal below bore in

pump housing . . . . . . . . . . . . . . . . i; :0&o”,;;

2- impeller flush to housing

within . . . . _ . . . . . . . . 0.0020 in.
(0.51 mm)

3 - Pulley above end of shaft

flush . . . . . . . ..t.~........ 0.0020 in.
0 (0.51 mm)

l’43755N

Fig. Pl-Water Pump

THERMOSTATS, HOUSINGS, AND PIPING

SPECIFICATIONS AND TORQUE VALUES

Thermostat opening temperature . . . . . . . _. . . 180°F

(82°C)

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 Engine 4
JD750 Crawler Bulldozer
Specifications and Special Tools 0499-19
TM- 1136 (Nov-78)

ENGINE OIL COOLER

SPECIFICATIONS AND TORQUE VALUES

1 - Oil cooler-bypass valve spring

free length (approximately) . .. .2.70 in.
(68.5 mm)

Oil cooler bypass valve

spring compressed at 32.5 to
39.5 lb (145 to 176 N) (15 to 18 kg) .1.91 in.
(48.5 mm)

T34733
0
Fig. 22-Oil Cooler Bypass Valve Spring

I
Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0499-20 Specifications and Special Tools TM-1 136 (Nov-78)

STARTING SYSTEM
SPECIFICATIONS AND .TORQUE VALUES
DELCO-REMY STARTING MOTOR I
No Load Test

Test Volts Min. Amps Max. Amps Min. RPM Max. RPM

20 60’” 80* 5500 7500

*Includes solenoid

Solenoid Test

Pull-In (current draw at 5 volts) ................................................. .. 10 to 11.4 amps

Hold-in (current draw at 20 volts) ............................................... ... 6.1 to 6.8 amps

Fig. 23-Starting Motor

1 - Bushing, Drive Housing

I.D. .. . ... . ... . .0.625 - 0.627 in.
“(15.88 - 15.92 mm)
Wear tolerance . . . . . . . . . . . . 0.0636 in.
(1.62 mm)
Oil clearance . .. . . . 0.002 - 0.004 in.
(0.05 - 0.10 mm)
Wear tolerance .. .. . . . . . . . . . . . 0.015 in.
(0.38 mm)

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM-l 136 (Nov-78) Specifications and Special Tools 0499-21

STARTING SYSTEM
SPECIFICATIONS AND TORQUE~ALUES-Continued

DELCO-REMY STARTING MOTOR I

2 - Bushing, Lever Housing (See Fig. 23)

I.D. . . . .... ...... 0.843 - 0.844 in.
(21.41 - 21.49 mm)
Wear tolerance.. . . . . . . . . . . . . . . .0.085 in.
(2.16 mm)
Oil clearance.. . . . . . . . 0.019 - 0.021 mm
(0.48 - 0.53 mm)
Wear tolerance. . . . . . . . . . . . . . . . . . . .0.027 in.
(0.69 mm)

3 - Bushing, Commutator End Frame (See Fig. 23)

I.D. . . . . . . ... . . . . 0.5635 - 0.5645 in.
(14.31 - 14.34 mm)
Wear tolerance. . . . . . . . . . . . . . . . .0.573 in.
(14.55 mm)
Oil clearance.. . . . . . . . . . 0.002 - 0.004 in.
(0.05 - 0.10 mm)
Wear tolerance. . . ,. . . . . . . . . . . 0.015 in.
(0.38 mm)

4 - Commutator End Frame,, Lever Housing

and Drive Housing Attaching Screws (See Fig. 23)
Torque . . . . . . . . . . . . . .13 - 17 lb-tt
(18 - 23 Nm) (2 kg-m)

l- Pinion clearance .. . . . 23/64 t l/32 in.

‘(9.13 2 0.80 mm)

Fig. 24-Pinion Clearance

Litho in U.S.A.
4 Engine JD 750 Crawler Bulldozer
0499-22 Specifications and Special Tools TM- 1136 (Nov-78)

STARTING SYSTEM
SPECIFICATIONS AND TORQUE VALUES
JOHN DEERE STARTING MOTOR

No Load Test

Current draw .......................................................... .70 amps maximum at 24 volts

Armature speed ................................................................ 4400 rpm and higher

Windings, Pull-In ....................................................................... 74 amps max.

Windings, Hold-In ..................................................................... .6.1 amps max.

Fig. 25-Starting Motor

Starting Motor Model 28000-2970-ND

1 - Commutator and drive

housing bushing I.D. . 0.6693 to 0.6704 in.
(17.000 to 17.028 mm)
Wear tolerance (maximum) . . . . . . . .0.6740 in.
(17.120 mm)
Oil clearance. . .. .. . . 0.0036 to 0.0070 in.
(0.091 to 0.178 mm)
Wear tolerance (additional) . . . . . .0.016 in.
(0.41 mm)
Depth . . .. ..... . . 0.008 to 0.022 in.
(0.20 to 0.56 mm)

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JD750 Crawler Bulldozer Engine 4
TM-l 136 (Nov-78) Specifications and Special Tools 0499 -23

STARTING SYSTEM
SPECIFICATIONS AND TORQUE VALUES-Continued
JOHN DEERE STARTING MOTOR

2 - Center housing bushing

(Fig. 25) I.D.. .. .. . . . . 1.182 to 1.184 in.
(30.02 to 30.07 mm)
Wear tolerance (maximum) . . . . . . . . . 1.189 in.
(30.20 mm)
Oil clearance wear
tolerance . . . . . . . , . . . . . . . . . . . .0.0236 in.
(0.600 mm)
Depth . . . _. . . . . . . . . . . 0.017 to 0.037 in.
(0.43 to 0.94 mm)
3 - Armature (Fig. 25)
Armature runout. . . . . . . . . . . . . . . . . . .0.006 in.
(0.15 mm)
Commutator runout . . . . . . . . . . . . . . . . 0.016 in.
(0.41 mm)
Commutator minimum undercut . . . . . .0.008 in.
(0.20 mm)
Commutator O.D.. . . . . . . . . . . . . . . . . .1.77 in.
(44.9 mm)
4 - Torque-pole shoe screws
(Fig. 25). . . . . . . . . . . . . . . . . . . . . . 30 lb-ft
(41 Nm) (4 kg/m)
5 - Torque-shift lever pivot
screw (Fig. 25) . . . . . . . . . . . . . . . . . . . 30 lb-ft
(41 Nm) (4 kg/m)
6 - Torque-center bearing
housing to field frame
(Fig. 25). . . . . . . . . . _. . . . . . . . . 6 lb-ft
(8 Nm) (0.8 kg/m)
7 - Torque--commutator frame and
drive housing (Fig. 25) . . . . _ . . . . . . . . . . 10 lb-ft
(14 Nm) (1 kg/m)
8 - Clearance between pinion
and pinion stop (Fig. 25) . . . . 0.012 to 0.185 in.
(0.30 to 4.70 mm)

1 - Brush minimum length . . . . . . ~. . . . . . . . .5/8 in.

(15.88 mm)

Fig. 26-Measuring Brush Lengeh

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4 Engine JD 750 Crawler Bulldozer
0499-24 Specifications and Special Tools TM-1 136 (Nov-78)

STARTING SYSTEM
SPECIFICATIONS AND TOR UE VALUES-Continued
JOHN DEERE ST P RTING MOTOR

1 - Brush spring minimum

tension . . ........... .. . . . . . . 40 02
(11 NJ (1 kg)

Fig. 27-Checking Brush Spring Tension

Litho in U.S.A.
JD750 Cm wler Bulldozer Engine 4
TM- 1136 (Apr- 79) Specifications and Special Tools 0499-25

FAN DRIVE
SPECIFICATIONS AND TORQUE VALUES

1 - Idler pulley special screw I

/--- 4
\
torque. . . . . . . . . . . . . . . . . . . . . . . . . . 55 lb-ft
(75 Nm) (8 kg-m)
1

u T62006N

Fig. Z&/dler Pulley

FLYWHEEL, HOUSING AND FASTENERS

SPECIFICATIONS AND TORQUE VALUES

1 - Special cap screw torque

“D” Grade Cap Screws . . . . . . . . . . . . . 85 lb-ft
(115 Nm) (12 kg-m)
“F” Grade Cap Screws . . . . . . 120 lb-ft
(163 Nm) (17 kg-m)
Starter gear maximum temperature
(in oil). . . . . . . . . . . . . . . . . . . 360°F
(180°C)
(in oven)........................... 420°F
(216%)
Number of starter gear teeth . . . . . . . . 129
TP3756N Flywheel housing to block cap screw torque
3/8-in. cap screw . . . . . . . . . . . 35 lb-ft
Fig. 29-Flywheel (47 Nm) (5 kg-m)
5/8-m. cap screw . . . . . . . . . . . . . 170 lb-ft
(230 Nm) (24 kg-m)

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0499-26 Specifications and Special Tools TM- I 136 (Apr- 79)

ENGINE REMOVAL AND INSTALLATION

SPECIAL TOOLS

Convenience Tools
Tool Number Use

DO1043AA Load positioning sling - To remove

and install engine in unit. Comes
with one set of JDG-19 Lifting
Brackets.

T47209N

Fig. 3Moad PositioningSling

JDG-19 Lifting bracket - Used with

dOlO43AA load positioning sling
for engine removal and installa-
tion.

T54722N

fig. 31 -Lifting Brackefs

DO1003AA Engine stand and adapter plates

(Formerly used to hold engine after removal
JDST-32) from unit.
and D05002ST

T47199N

Fig. 32-Engine Stand

litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-78) Specifications and Special Tools 0499-27

CRANKSHAFT AND MAIN BEARINGS

SPECIAL TOOLS

Essential Tools

TOOI Tool Number Use

JDH-7 Crankshaft Gear Driver - To install

gear on crankshaft.

T34735N

Fig. 33-Driver

JDE-2A Rear Bearing Oil Seal Driver - To

install rear oil seal.

T34736N
Fig. 34-Driver

JD-250 Crankshaft Front Oil Seal Dri er -

To install crankshaft front oil l eal.

T32 58/N

Fig. 35-Driver

Litho in U.S.A.
 4 Engine JD750 Crawler Bulldozer
0499-28 Specifications and Special Tools TM-l 136 (Nov-78)

CRANKSHAFT AND MAIN BEARINGS

SPECIAL TOOLS

Essential Tools

Tool Tool Number Use

JD-251-5 Rear Crankshaft Oil Seal Installa-

tion Set - includes JD-251-3 Pilot
Ring and JD-251-4 Seal Protec-
tor, used with JD-251 to install
rear crankshaft oil seal.

T31583N
Fig. 36Driver
/ / JD-251 Rear Crankshaft Oil Seal Driver -
To install rear crankshaft oil seal.

I Fig. 37Oiver

Litho in U.S.A.
JO750 Crawler Bulldozer Engine 4
TM- 1136 (Apr-79) Specifications and Special Tools 0499.29

CAMSHAFT AND VALVE ACTUATING MEANS

SPECIAL TOOLS

Essential Tools

TOOI Tool Number Use

JD-252 Idler Gear Bushing Driver - To in-

stall idler gear bushing.

T31584N

JD-254 Gear Timing Tool - To time gear

train.

F@. 39-Gear liming Tool

JD-250 Front Crankshaft Oil Seal Driver -

To install front crankshaft oil seal

0
in timing gear cover.

T31581N

F@. 40-Driver
a

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0499-30 Specifications and Special Tools TM- 1136 (Apr- 79)

CAMSHAFT AND VALVE ACTUATING MEANS’

SPECIAL TOOLS-Continued
--
Convenience Tools

Tool Tool Number Use

JDE-83 Flywheel Turning Tool - To rotate

flywheel when timing engine.

Fig. 41-Flywheel Turning Tool

CONNECTING RODS AND PISTONS

SPECIAL TOOLS

Essential Tools

Tool Tool Number Use

JDE-62 Ring Groove Wear Gauge - To

measure keystone ring groove
wear.

Fig. 42-Keystone Ring Groove Wear Gauge

JDE-135 Piston Ring Expander _ To install

(Formerly piston rings.
JDE-85)

Fig. 43-Piston Ring Expander

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JD 750 Crawler Bulldozer Engine 4
TM-l 136 (h@v-78) Specifications and Special Tools 0499-31

CONNECTING RODS ANIl PISTONS

SPECIAL TOOLS-Continued

Essential Tools-Continued

Tool Tool Number Use

JDE-286 Bushing Tool - To remove and in-

stall piston pin bushings in con-
necting rod.

T32805NY

Fig. 44-Bushing Installation and Removal

Tool

JDE-84 Piston Ring Compressor - To in-

stall pistons.

Fig. 45-Piston Ring Compressor

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 4 Engine JD750 Crawler Bulldozer
0499-32 Specifications and Special Tools TM-1 136 (Nov-78)

CYLINDER BLOCK
SPECIAL TOOLS

Essential Tools

Tool Tool Number Use

JD-251 Crankshaft Rear Oil Seal Driver -

To install crankshaft rear oil seal

T31

I Fig. 46-Driver

^” ..e.:;,, :,,
‘ D-l 7004BR Cylinder Brush - Deglaze cylinder 1
liners.

Fig. 47-Deglazing Brush

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 JD 750 Crawler Bulldozer Engine 4
TM-2 136 (Nov-78) Specifications and Special Tools 0499-33

CYLINDER BLOCK
SPECIAL TOOLS-Continued

Essential Tools-Continued

Tool Tool Number Use

e
JD-251-5 Rear Crankshaft Oil Seal Installa-
tion Set - includes JD-251-3 Pilot
Ring and JD-251-4 Seal Protector
used with JD-251 to install rear
crankshaft oil seal.

I Fig.48-Seal /nsfa/lafion Set

Convenience Tools

Tool
Tool Number Use 1
q
D-01 062AA Cylinder Liner Puller - To remove
cylinder liners.
D?i 1073AA

Fig. 49-Cylinder Liner Puller

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 4 Engine JD750 Crawler Bulldozer
0499-34 Specifications and Special Tools TM-1 136 (Nov-78)

CYLINDER BLOCK
SPECIAL TOOLS-Continued

Convenience Tools-Continued

Tool Tool Number Use

T36746N
l-lo” (254.0 mm) 9-2.5” (63.5 mm) 17-5/16”-18 Tap
2-5” (127.0 mm) 10-l” (25.4 mm) 18-2.75” (69.85 mm) Radius
3-1.5” (38.1 mm) 11-0.25” (6.35 mm) 19-4” (101.6 mm)
4-16” (405.4 mm) 12-6” (152.4 mm) 20-4.38” (111.25 mm)
5-13” (330.2 mm) 13-0.328” Drill Through 21-2.38” (60.45 mm)
6-0.375” (9.52 mm) 14-5116”-18 Tap 22-5116” x 1” Cap Screw
7-0.5” (12.7 mm) 15-2 used 23-2.5” (63.5 mm) Angle Iron
, 8-1.25” (31.8 mm) 16-12” (304.8 mm)

Fig. SO-Cylinder Liner Holding Fixture

. * Liner Holding Fixture - Hold liner

for deglazing.

*Make in dealer’s shop

Litho in U.S.A.
- JD7.50 Crawler Bulldozer Engine 4
TM- 1136 (Nov-78) Specifications and Special Tools 0499-35

CYLINDER HEAD AND VALVES

SPECIAL TOOLS

Essential Tools

Tool Number USe

I
D-20002WI Knurling Tool - To knurl engine
valve guide.

TS9818N

Fig. 51- Knurling Tool

JDE-7 Driver - To install valve seat in-

serts.

T27596N
I Fig. 52-Driver

Litho in U.S.A.
 4 Engine JD750 Crawler Bulldozer
0499-36 Specifications and Special Tools TM- 1136 (Nov-78)

CYLINDER HEAD AND VALVES

SPECIAL TOOLS-Continued

Essential Tools-Continued

Tool Number Use

JDE-77 Valve Seat Puller - to remove in-

take valve seat inserts.

JDE-87 Valve Seat Puller - to remove ex-

haust valve seat inserts.

P33181N
:” 1 Fig. 53-Valve Seat Puller

JDE-86 Replacement Ring - Used with

JDE-7 Driver to install valve seat
inserts.

T27594~

Fig. M-Replacement Ring

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 JD750 Cm wler Bulldozer Engine 4
TM-1 136 (Nov-78) Specifications and Special Tools 0499-37

FUEL INJECTION SYSTEM

SPECIAL TOOLS

Essential Tools

Tool Tool Number Use i

JDE-38 Nozzle Puller - To remove fuel in-

jection nozzles.

Fig. 55-Nozzle Puller

JD-258 Carbon Stop Seal Installation Tool -

- To install carbon stop seal on ,
nozzles. d

Fig. 56-Seal lnsfallafion Tool

JDE-39 Nozzle Bore Cleaning Tool - To

clean nozzle bore in cylinder
head.

Fig. 57-Cleaning Tool

19918 Timing Window - To adjust injec-

tion pump cam advance.

T3192ON

I Fig. 584njection Pump Timing Window

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4 Engine JD7!50 Crawler Bulldozer
0499-38 Specifications and Special Tools TM- 1136 (Nov- 78)

FUEL INJECTION SYSTEM

SPECIAL TOOLS-Continued

Essential Tools-Continued

TOOI Tool Number Use

* ---
Modified Flare Nut Wrench - To
remove and install injection lines to
injection pump.

Heat wrench in area to be bent.

Use template (Fig. 59) to shape
wrench. Air cool.

T61916N

*Make in dealers shop.

Fig. 59-Modified Flare Nut Wrench (Full Size Template)

Litho in U.S.A.
 Engine 4
JD750 Crawler Bulldozer
TM- 1136 (Nov-78) Specifications and Special Tools 0499-39

FUEL INJECTION SYSTEM

SPECIAL TOOLS-Continued

Essential Tools-Continued
TOOI Tool Number Use

* --- Modified Open End Wrench - To

remove and install injection pump
inner mounting stud nut.

cut two 112” Combination

Wrenches in half. Cut l/8” open
end from one end of the cut-off
wrench. Weld open end to wrench
body (Fig. 60). Weld the two
wrench bodies together (Fig. 60).
Approximate wrench length should
be 8-3/4 inches (222 mm).

*Make in dealers shop.

Fig. 60-Modifid l/2” Open End Wrench
(Full Size Template)

Litho in U.S.A.
4 Engine JD750 Cra wier Bulldozer
0499-40 Specifications and Special Tools TM-1136 (Nov-78)

TURBOCHARGER
SPECIAL TOOLS

Essential Tools

Tool Too Number Use

JD274 Turbocharger Snap Ring Assem-

bly Tools - To install the Turbine
shaft bearing snap rings in the
body of the AiResearch turbo-
charger.
JO-274-1 JO-274-2 JO-274-3

l’27629N

Fig. bl-Snap Ring Assembly Tools

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-78) Specifications and Special Tools 0499-41

TURBOCHARGER
SPECIAL TOOLS-Continued

Convenience Tools

Tool Tool Number Use

*a- Turbine Wheel Holding Fixture -

To hold turbocharger during disas-
sembly

I
I

k------e-
T27631N

l-3/4” (19 mm) 7-2-112” (63.5 mm)

2-314” (19 mm) 8-2-314” (70.3 mm)
3-3/4” (19 mm) 9-318” (10 mm)
4-Bore to Clear Diameter, 11 Places
Wheel Hub Equally Spaced
5--6-l/2” (165 mm) 10-l” (25.4 mm)
6-6-l/2” (165 mm)

Material: Hardwood or Aluminum

Fig. 62-Turbine Wheel Holding Fixture

*Make in dealers shop.

Litho in U.S.A.
 4 Engine JD750 Crawler Bulldozer
0499-42 Specifications and Special Tools TM-1 136 (Nov-78)

WATER PUMP
SPECIAL TOOLS

Essential Tool

Tool Tool Number Use

JDE-112 Seal Driver and Handle - to install

and and properly locate water pump
27488 inner seal.

T51079N
Fig. 63-Seal Driver Set
I

Convenience Tools

q1
Tool Tool Number Use

27495 Disk.
27505 Disk.
27488 Handle - to remove water pump
inner seal.

T5108ON

Fig., 64-Seal Driver Sef

D-01218AA Knife-Edge Puller -to remove inner

and outer water pump bearings.

T51081N

Fig. 65-Knife-Edge Puller

I

Lifho in U.S.A.
JD 750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-78) Specifications and Special Tools 0499-43

STARTING SYSTEM
SPECIAL TOOLS

Essential Tools

Tool Number Use

Commutator and Drive End Bushing Tools

1 - 27487 Handle - For removing and install-

ing commutator and drive end
bushings.

2 - 27494 Disk - For removing commutator

T27670N u and drive end bushing.

Fig. 66-Bushing Removal

27495 Disk - For installing commutator
and /nsfa//afion Tool
and drive end bushing.

3 - 27491 and
27492 Disk Spacer - For removing and
installing commutator and drive end
bushing.

4 - 27493 Disk Pilot - For removing and in-

stalling commutator and drive end
bushing.

Litho in U.S.A.
4 Engine JD750 Crawler Bulldozer
0499-44 Specifications and Special Tools TM-l 136 (Nov-78)

STARTING SYSTEM
SPECIAL TOOLS-Continued

Essential Tools-Continued

Tool Tool Number Use

Center Bushing and Oil Seal Tools (See Fig. 66)

1 _ 27487 Handle - For installing center

bushing and oil seal.

2 - 27505 Disk - For installing center bush-

ing.

3 - 27512 Disk - For installing center oil

seal.

4 - 27501 Disk Pilot - For installing center

bushing and oil seal.

Commutator and Drive End Bushing Tool

Dimension Removal lnstallalion

"B" DIA.

A 1 in. 1 in.
(25 mm) (25 mm)
B 0.732 to 0.736 in. 0.732 to 0.736 in.
(18.59 to 18.69 mm) (18.59 to 18.69 mm)
C 0.661 to 0.665 in. 0.661 to 0.665 in.
(16.79 to 16.89 mm) (16.79 to 16.89 mm)
D 2 in. 3.94 in.
(51 mm) (100.08 mm)
E 0.901 to 0.909 in. 0.018 to 0.022 in.
(22.89 to 23.09 mm) (0.46 to 0.56 mm)
R 18972
F 0.783 to 0.791 in. 0.783 to 0.791 in.
Fig. 67-Dimensions for Shop-Made Bushing Driver (19.89 to 20.09 mm) (19.89 to 20.09 mm)

Litho in U.S.A.
JD750 Crawler Bulldozer Engine 4
TM- 1136 (Nov-78) Specifications and Special Tools 0499-45

STARTING SYSTEM
SPECIAL TOOLS-Continued

Essential Tools-Continued

Tool Tool Number Use

Center Bearing Bushing Tool (See Fig. 67)

Dimension Removal Installation

1.57 in. 1.57 in.
(39.9 mm) (39.9 mm)
1.36 to 1.37 in. 1.36 to 1.37 in.
(34;5 to 34.8 mm) (34.5 to 34.8 mm)
1.17 to 1.18 in. 1.17 to 1.18 in.
(29.7 to 30.0 mm) (29.7 to 30.0 mm)
2 in. 2 in.
(50.8 mm) (50.8 mm)
0.95 to 1.02 in. 0.018 to 0.02 in.
(24.1 to 25.9 mm) (0.46 to 0.51 mm)
0.866 to 0.945 in. 0.966 to 1.000 in.
(22.0 to 24.0 mm) (25.54 to 25.40 mm

JDE-80 Starter Wrench - To remove an d

install rear mounting nut on startin 9
motor.

Fig. 68-Starter Wrench

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 4 Engine JD 750 Crawler’ Bulldozer
0499-46 SDecifications and SDecial Tools TM-l 136 (Nov-781

STARTING SYSTEM
SPECIAL TOOLS

Convenience Tools

Tool Tool Number use

To test armature for shorts, opens,

and grounds.

q1
I Fig. 69-Armature Tester

To undercut armature and commu-

tator.

Fig. 70-Armature and Commutator Turning

and Undercutting Tool

Litho in U.S.A.
JD750 Crawler Bulldozer Engine Auxiliary Systems 5
TM- 1136 (Apr- 79) Cold Weather Starting Aids 0505-l

Section 5
ENGINE AUXILIARY SYSTEMS

CONTENTS OF THIS SECTION

Page Page
GROUP 0505 - COLD WEATHER GROUP 0520 - INTAKE SYSTEM
STARTING AIDS General Information .................... 0520-l
General Information .................... 0505-3 Removal .............................. 0520-l
Starting Aid Solenoid Repair ................................ 0520-2
Removal ............................ 0505-3 Installation. ............................ 0520-2
Repair .............................. 0505-3
Installation. .......................... 0505-3 GROUP 0530 - EXTERNAL EXHAUST
Starting Aid Switch SYSTEMS
Removal ............................ 0505-3 Removal .............................. 0530- 1
Repair .............................. 0505-4 Repair ................................ 0530-l
Installation. .......................... 0505-4 Installation ............................. 0530-2
Starting Aid Adapter, Line and Nozzle .:
Removal ............................ 0505-4 GROUP 0540 - MOUNTING FRAME

q
Repair .............................. 0505-4 Removal .............................. 0540-l
Installation. .......................... 0505-4 Repair ................................ 0540-l
Installation ............................. 0540-l
GROUP 0510 - ENGINE COOLING SYSTEM
General Information .................... 0510-l GROUP 0560 - EXTERNAL FUEL SUPPLY
Removal .............................. 0510-l SYSTEM
Repair ................................ 051 O-2 General Information .................... 0560-l
Installation. ............................ 0510-3 Removal .............................. 0560-l
Repair ................................ 0560-2
GROUP 0515 - SPEED CONTROLS Installation ............................. 0560-2
General Information. .................... 0515-l
Removal ............................... 0515-l GROUP 0599 - SPECIFICATIONS AND
Repair ................................. 0515-5 SPECIAL TOOLS
Installation ............................. 0515-5 Specifications and Torque Values
Cold Weather Starting Aid ............ 0599-l
Engine Cooling System ............... 0599-l
Speed Controls ...................... 0599-l 1
Mounting Frame ..................... 0599-2
External Fuel Supply System. ......... 0599-2

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5 Engine Auxiliary Systems JD750 Crawler Bulldozer
0505-2 Cold Weather Starting Aids TM- 1136 (Apr- 79)

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JD750 Crawler Bulldozer Engine Auxiliary Systems 5
TM- 1136 (Nov-75) Cold Weather Starting Aids 0505-3

Group 0505
COLD WEATHER STARTING AIDS

GENERAL INFORMATION Installation

The cold weather starting aid on the crawler con- Mount solenoid and can and connect wires and
sists of a starting aid solenoid with fluid container, a tube.
tube from the solenoid to a nozzle in the air intake
manifold and a button switch. STARTING AID SWITCH

The starting aid solenoid will spray fluid as long as Removal

the switch button is depressed when the transmis-
Remove screws from instrument panel and pull
sion is in neutral.
panel out just far enough to gain access to the
switch.
The starting aid switch is located on the instrument
panel. The solenoid and fluid can are located in the
Remove switch cap, disconnect wires, remove re- ’
transmission oil filter compartment.
taining hardware and remove switch.

IMPORTANT: To avoid engine damage, crank

engine one or two revolutions before depressing
starting aid switch. Depress starting fluid switch
only when the engine is cold and cranking.

IMPORTANT: To prevent dirt from entering the

engine, a container of starting fluid should be in
place on the solenoid at all times.

STARTING AID SOLENOID

Removal
Disconnect wires and tube from solenoid, remove
attaching hardware and remove solenoid.

Repair
Fig. l-Starting Aid Switch
The solenoid is not repairable. If the solenoid is
defective, it should be replaced.

Test solenoid as described in Section 90, Group

9015.

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5 Engine Auxiliary Systems JD750 Crawler Bulldozer
0505-4 Cold Weather Starting Aids TM- 1136 (Nov- 75)

Repair STARTING AID ADAPTER, LINE AND

NOZZLE
The switch is not repairable. If the switch is defec-
tive, it must be replaced.
gy
Removal
Test the switch as described in Section 90, Group Remove line by disconnecting at starting aid sole-
9015. noid and at nozzle holder.

Installation Unscrew nozzle holder from air intake manifold

and remove nozzle and holder.
Install switch, connect wires and install instrument
panel.
Repair
Be sure hose and openings in nozzle are open.
Clean or replace as necessary.

Installation
Install nozzle and holder with arrow on nozzle
pointing toward center of engine.

Connect line to solenoid and nozzle holder. ‘

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JD750 Crawler Bulldozer Engine Auxiliary Systems 5
TM- 1136 (Apr- 79) Engine Cooling System 0510-l

Group 0510
ENGINE COOLING SYSTEM

GENERAL INFORMATION
The engine cooling system consists of the radiator,
fan, and transmission system oil cooler.

The radiator is located at the front of the crawler

and is of the tube and fin type core construction. The
pressure type radiator cap is located on the top of
the radiator to maintain pressure in the cooling sys-
tem.
fig. 2-Hydraulic Hose Connections
REMOVAL

Fig. l-Fitting Guard

Remove fitting guard (Fig. 1). Remove grille screen

and baffle.

Drain radiator.

Disconnect hydraulic hoses (Fig. 2) for removal of

grille housing.
Fig. 343lade Lift Cylinders Removal

Remove engine side shields, muffler, pre-cleaner, On early units equipped with air conditioning, re- 1
hood and hood extension. move condenser from radiator (it is not necessary to
disconnect hoses to the condenser).
Remove blade lift cylinders at points shown in Fig. 3.
Use suitable lifting equipment as cylinders are heavy. Remove fan shroud and sand shield. Detach trans-
mission oil cooler from radiator.
Remove upper radiator support to allow clearance
to remove radiator. IMPORTANT: Do not disconnect the oil lines to
the cooler. Disconnect only the coolant hoses.
Remove grille housing using a l-ton (907 kg) mini-
mum capacity hoist. Remove the radiator.

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5 Engine Auxiliary Systems JD750 Crawler Bulldozer
051 o-2 Engine Cooling System TM-l 136 (Apr-79J

REPAIR IMPORTANT: Do not attempt to repair a dam-

aged fan. The fan should always be replaced if
Refer to Cooling Systems in FOS Manual - damaged.
ms ENGINES - for radiator inspection and
repair.
cl 0

-"-WOSTAT
,ING
:R

WATER PUMP

I 11’3

/
0

II
T43102

l-Radiator Cap 7-End Gasket (4 used) 13-Gap Screw (48 used)

~-TOP Tank 8-Front Gasket (4 used) 14-L.H. Side
3-Nut (48 used) 8-Bolting Bar (4 used) 15-Bottom Tank
4-Lock Washer (48 used) lO-R.H. Side M-Drain Cock
5--Hose 11-End Bar (4 used) 17-Hose
8-Clamp (4 used) 12-Radiator Core

Fig. 4-Radiator

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JD750 Crawler Bulldozer Engine Auxiliary Systems 5
TM- 1136 (Apr- 79) Engine Cooling System 0510-3 -

INSTALLATION Use lithium base grease to lubricate shaft ends of

fan blades of the Huber reversible fan (Fig. 6).
Follow removal procedure in reverse order.
Fasten the Huber fan to the pulley using l-inch (25.4
mm) cap screws only.

Apply Permatex No. 2 or equivalent to fan hub

surface and install cover to the Huber fan.

Torque the radiator upper supports cap screws to 45

+ 5 lb-ft (5.1 t 0.6 Nm) (0.52 & 0.06 kg-m).

Torque the radiator lower support cap screws to 85

r 8 lb-ft (115 2 10 Nm) (11 ? 1 kg-m).

Fill radiator with clean soft water and proper addi-

tive. Fill to a level two inches below top of the filler
Fig. 5-Switzer Reversible Fan
neck. I

Fasten the Switzer reversible fan to the pulley using

l-1/4 inch (31.8 mm) cap screws only.

Fig. b-Huber Reversible Fan

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5 Engine Auxiliary Systems JD750 Crawler Bulldozer
0510-4 Engine Cooling System TM- 1136 (Apr- 79)

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JD750 Crawler Bulldozer Engine Auxiliary Systems 5
TM-l 136 (Nov-78) Speed Controls 0515-l

Group 0515
SPEED CONTROLS
GENERAL INFORMATION REMOVAL
The speed control system consists of a hand control Refer to Figs. 1, 2,3,4 and 5 when removing speed
lever which is connected to the injection pump and control linkage components.
transmission control valve by means of control cable
and linkage.

ENGINESPEED
CONTROLSHAFT
AND LEVERS

l-Cap Screw 7-Engine Speed Cable 13-Nut (4 used)

2-Clamp (4 used) 8-Gap Screw 14-Pips Spacer
3-Gable Support 9-Washer (2 used) 1%Lock Washer (2 used)
4-Gap Screw (2 used) 1 O-Cap Screw. (2 used) 16-Injection Pump Lever
5-Ball Joint (2 used) 1 l-Cable Support 17-Trunnion
6-Jam Nut (3 used) 12-Special Washer (3 used)

Fig. l-Engine Speed Control Cable and Supports

Lithoja-U.S.A.
 5 Engine Auxiliary Systems JD750 Crawler-Bulldozer
0515-2 Speed Controls TM- 1136 (Nov-78)

CONTROL
SUPPORT

T62032N

l-Nut (2 used) 5-Ball Joint (2 used) g-Special Set Screw (3 used)

2-Lack Washer (2 used) ( -242796) 6-Rod Assembly lo-Nut (2 used) ( -242796)
3-Gable Lever 7-Gap Screw (2 used) Ii-Lever (2 used)
4-Jam Nut (2 used) 6-Bearing (2 used) 12-Gross Shaft

Fig. 2-Engine Speed Control Linkage

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JO750 Crawler Bulldozer Engine Auxiliary Systems 5
TM-1 136 (Nov-78) Soeed Controls 0515-3
j I FORWARD AND

4,
FORWARD AND REVERSE
SPEED CONTROL LEVER
LINKAGE

ENGINE SF;EED 1
CONTROL LINKAGE
T44744
l-Special Set Screw (4 used) !bBearing (4 used) 9-Shaft
2-Jam Nut (4 used) 6-tap Screw (4 used) lO-Shaft
3-Lever (2 used) 7-Lock Washer (4 used) 11-Lever (2 used)
4-Plug (2 used) G-Complete Control Support

Fig. 3-Engine Speed Control Sumrt

Lithojn U.S.A.
5 Engine Auxiliary Systems JD750 Crawler Bulldozer
0515-4 Speed Controls TM- 1136 ‘(Nov-78)

SPEED CONTROL

SPEED CONTROL
SUPPORT LEVER

-CS11*
B
T42781
I-Knob 5-Control Arm &Lock Washer (2 used) ( -2427%:
P-Lever 6-Roller Bearing g-Cap Screw (2 used)
3-Gap Screw 7-Nut (2 used) ( -242796) lo--Ball Joint (2 used)
4-Lock Washer Lock Nut (2 used) 11 -Jam Nut (2 used)
12-Rod Assembly

Fig. 4-Throttle Lever and Control Arm

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JD 750 Crawler Bulldozer Engine Auxiliary Systems 5
TM-1 136 (Nov-78) Speed Controls 0515-5

.4
SPEED CONTROL

T42783 a

l-Oil Seal 4-Sei Screw (3 used) a--Facing (6 used)

Z-Dowel (2 used) &Plate g--Separator Plate (2 used)
3-Speed Control Head 6-Spring (3 used) 10-Shaft
Housing 7-Pressure Plate

Fig. 5-Engine Speed Control Mad

REPAIR INSTALLATION
Refer to Figs. 1 through 4 for repair of the speed Refer to Fig. 5 for speed control head installation.
control linkage.
Apply T43512 John Deere Loctite Thread Lock and
Replace any parts that are worn or seem question- Sealer or equivalent to the tapped holes of the housing
able. Parts should move freely. (3). Assemble the set screws (4) flush with the inside
wall of the housing.

Lubricate shaft (10) and assemble shaft into speed

control head housing.

Lifho in U.S.A.
5 Engine Auxiliary Sysfems JD750 Crawler Bulldozer
05156 Speed Controls TM- 1136 (Nov- 78)

Install plate (5). Install the springs (6), alternating the Install separator plate and install third set of facings.
--x
dish of the springs with the first spring installed with ‘the
inside dished out away from the seal (1). Adjust speed control head set screws (4Tevenly until
the torque on shaft measures 225 2 25 lb-in (25 ? 2.8.
Ins@ll pressure plate (7). Nm) (2.6 + 0.29 kg-m).

Install first set of facings (8), one on each dowel. Refer to Section 90, Group 9026 for engine speed
control linkage adjustment. Follow procedure for low
Install separator plate (9) and install second set of and high idle and procedure for transmission control
facings (8). valve synchronization.

Lifho in U.S.A.
 JO 750 Crawler Bulldozer Engine Auxiliary Systems 5
TM-l 136 (NOW78) intake System 0520-l

Group 0520
INTAKE SYSTEM
GENERAL INFORMATION REMOVAL
The air cleaner assembly consists of two filter ele- Remove exhaust stack, pre-cleaner, engine side
ments and an air restriction indicator. shields and hood.

Air enters the air cleaner body and passes through Remove air cleaner.
the primary element to remove impurities. If the pri-
mary element fails, the safety element will remove
dirt particles.

The air restriction indicator, mounted on the radiator

upper support, shows red when excessive restriction is
i present in the intake system.

KY-
CT5
TURBOCHARGER COIIPRESSOR
UnlI~lNl:.
,,“.,-*..-
\ I1 -3 12
)c 32

L”

T43104

l-Cap (Without Pre-Cleaner) &Baffle 16-Bracket (2 used)

P-Clamp g--Special Nut 16-Lock Washer (6 used)
3-Extension IO-Element V-Cap Screw (6 used)
4-Dust Cup 1 l-Element 1 &Hose
%-Special Bolt ll-Air Cleaner Assembly 14-Clamp
6-Clamp 13-Gap Screw (2 used) PO-Clamp
7-O-Ring M-Special Washer (2 used)

Fig. l-Air Cleaner Assembly

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5 Engine Auxiliary Systems JO750 Crawler Bulldozer
0520-2 intake System TM-l 136 (Nov-78)

REPAIR INSTALLATION
Replace the filter elements if damaged, after one Follow removal procedure in reverse order.
year of service, or if element is not responding to
cleaning, indicated by excessive smoke or loss of Check all air intake system fittings for possible air
power. leaks.

IMPORTANT: Any time the air cleaner assembly

is serviced, a check for intake tube clamp tightness
and air intake system air leaks should be made.

Refer to FOS Manual - ENGINES - for in-

0 Fos

Q
formation on cleaning air cleaner elements.

NOTE: Never operate engine without filter element

and cover in place.

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JD750 Crawler Bulldozer Engine Auxiliary Systems 5
TM- 1136 (Apr- 79) External Exhaust Systems 0530-l

Group 0530
EXTERNAL EXHAUST SYSTEMS
REMOVAL Remove cap screw (19) attaching muffler collar (20)
to muffler.
Remove clamp (4, Fig. 1) attaching muffler (1) to the
exhaust elbow.
Lift muffler off exhaust elbow.

Remove bolts (2) attaching muffler to muffler sup-

REPAIR
3ort (9).
Replace rusted or damaged parts.

,17

EXHAUST
ELBOW

T6620lN

l-Muffler 8-Cap Screw (2 used) 15-Exhaust Extension

2-Cap Screw (2 used) S-Support Bracket M-Exhaust Cover
3-Cap Screw (2 used) lo--Washer (2 used) 17-Lock Nut (2 used)
4-Clamp (2 used) 1 l-Nut +-Washer (use as required)
G-Washer (2 used) 12-Gap Screw 19-Cap Screw (2 used)
8-Nut (2 used) 13-Lock Washer 20-Muffler Collar (2 used)
7-Washer (2 used) M-Clamp

Fig. 1-External Exhaust

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5 Engine Auxiliary Systems JD750 Crawler Bulldozer
0530-2 External Exhaust Systems TM- 1136 (Apr- 79)

INSTALLATION
Position muffler inlet over exhaust elbow.

Install bolts attaching muffler to muffler support but

do not tighten nuts.

Install clamp attaching muffler to exhaust elbow.

Tighten nuts on muffler support bolts.

After hood is in place, install muffler collar. Use

washers at each end between collar halves to assure a
tight fit around the muffler and solid cap screw joints.

Install cap screws attaching muffler collar to muffler.

Position collar 0.3 in. (7.6 mm) above the hood when
measured at the ends of collar.

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JD750 Crawler Bulldozer Engine Auxiliary Systems 5
TM- 1136 (Aor- 791 Mounting Frame 0540-l

Group 0540
MOUNTING FRAME
REMOVAL INSTALLATION
Remove engine and splitter bottom guards. Tighten support frame cap screws.

Remove bolts from isolator mounts.

A CAUTION: Block engine and splitter se-

curely in the raised position to prevent in-
juries in case of lifting device failure.

Use jacks and/or hoist to raise engine and splitter

assembly far enough to remove lower rubber isolators
from between the main frame and engine mounting
frame.

Remove rubber isolators,

REPAIR
inspect rubber isolators for damage such as de-
terioration, cracking and tearing.

T65354N
\mJ
Inspect support frame for cracks and breaks.
l-Special Washer 3-Isolator Mount
Replace rubber isolators which are damaged. If new 2-Engine Mount 4-718 x 4-l/2-Inch
isolators are used, also use ‘F’ grade cap screws and Cap Screw
hardened washers.
Fig. l-Engine Isolator Mount

Repair or replace damaged support frame.

Position rubber isolators as shown in Fig. 1.
Check torque on engine support frame attaching cap
screws. Remove engine and splitter assembly support
blocks and lower assembly in position.

IMPORTANT: If older mounts are reused, do

not use ‘F’ grade cap screws as the higher torque
will damage the mounts. Do not use the older
special washers with ‘F’ grade cap screws as the
higher torque can cause the washers to dish as
well as remove material from the washers. ‘D’
grade cap screws can be used with newer mounts
but using ‘F’ grade cap screws is recommended.
Do not use both ‘D’ grade and ‘F’ grade cap screws.

Torque cap screws as follows:

‘D’ grade . . . . . . . . . . . . . . . . . . . . . . . . . 445 lb-ft
(603 Nm) (62 kg-m)
‘F’ grade .. .. .. . . 685 lb-ft
(929 Nm) (95 kg-m)

Lifho in U.S.A.
5 Engine Auxiliary Systems JD750 Crawler Bulldozer
0540-2 Mounting Frame TM- 1136 (Apr- 79)

Litho in U.S.A.
 Engine Auxiliary Systems 5
JD750 Crawler Bulldozer
External Fuel Supply System 0560-l
TM- 1136 (Nov-78)

Group 0560
EXTERNAL FUEL SUPPLY SYSTEM
GENERAL INFORMATION REMOVAL
The external fuel supply system consists of fuel Drain fuel from tank. Disconnect fuel lines.
tank and fuel lines.
Remove fuel tank using a l-ton (907 kg) minimum
The fuel tank is mounted behind the operator’s capacity hoist.
seat. A fuel strainer is located in the filler neck to
prevent dirt from entering the fuel tank. A drain valve
is located at the bottom of the tank.

T43168

l--Fuel Gauge 7-R.H. Mounting Bracket 13-Cover

2-Snap Ring 8-Washer (10 used) 14-Cover
3-Fuel Strainer g--Cap Screw (8 used) 15-L.H. Mounting Bracket
lO-Special Washer l&-Snap Ring
4--Gap
5-Gasket Ii-Cap Screw (12 used) 17-Cotter Pin (2 used)
8-Fuel Tank 12-Special Cap Screw (2 used)

Fig. l-Fuel Tank and Mounting Bracket

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 5 Engine Auxiliary Systems JD750 Crawler Bulldozer
0560-2 External Fuel Supply System TM- 1136 (Nov-78)

CENTER FUEL

CENTER FUEL
LINE

543189

l-Connector 5-Special Nut B-90’ Elbow

%--Rear Fuel Return Line GBolkhead Union B-Fuel Shut-Off Valve
3-Bulkhead Union 7-Rear Fuel Line l&Drain Cock
4-Nut

Fig. P-Fuel Tank Drain Valve and Rear Fuel Lines

REPAIR INSTALLATION
Install fuel tank and connect fuel lines.
A CAUTION: Cleaning and repairing a fuel
tank is very dangerous. Live sparks,
Be sure drain valve is closed and fuel shut-off valve
smoking, or fire of any nature should never be
is open. I
permitted in the vicinity of the cleaning br repair-
ing operation.

Check fuel tank for leaks.

Refer to FOS Manual - ENGINES - for de-

clIn3

0
tailed information on repair of fuel tanks.

hitho in U.S.A.
JD750 Crawler Bulldozer Engine Auxiliary Systems 5
TM- 1136 (Nov-75) External Fuel Supply System 0560-3

FRONT FUEL
HOSE

LINE

l-Connector 5-Plate (3 used) O-Spacer (2 used)

2-Nut 6-Clamp (4 used) lo-Nut
3-Cap Screw (2 used) 7-Center Return Line 1 l-Special Nut
4-Lock Washer (2 used) &-Center Fuel Line 12-Bulkhead Union

Fig, 3-Center Fuel Lines

Litho in U.S.A.
 i

5 Engine Auxiliary Systems JD750 Ciawler Bulldozer ’

0560-4 External Fuel Supply System TM- 1136 (Nov- 75)

FUEL TRANSFER
PUMP

\
P

T43193

l-Clamp (2 used) 345” Elbow

2-Leak-Off Hose 4-Fuel Line

Fig. 4-Front Fuel Lines

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JD750 Crawler Bulldozer Engine Auxiliary Systems 5
TM- 1136 (Apr- 79) Specifications and Special Tools 0599-l

Group 0599
SPECIFICATIONS AND SPECIAL TOOLS
SPECIFICATIONS AND TORQUE VALUES
COLD WEATHER STARTING AID
1 - Starting aid line hex. nut torque. 50 to 70 lb-in
(5.6 to 7.9 Nm) (0.6 to 0.8 kg-m)

Fig. l-starting Aid Line Hex. Nut

ENGINE COOLING SYSTEM

Cooling system capacity. . ... . . 7 gal.

(26.5 L)

Radiator test pressure. . . . . .. 10 psi

(1 bar)

Radiator cap test pressure .. . 6.25 to 7.50 psi

(0.4 to 0.5 bar)

Radiator upper supports

cap screw torque . . . . .45 i 5 lb-ft
(5.1 i 0.6 Nm) (0.52 5 0.06 kg-m)

Radiator lower support

cap screw torque . .85 t 8 lb-ft
(115 & IO Nm) (11 -I- 1 kg-m)

SPEED CONTROLS

Torque on engine speed control

head . . . . . . . . . . . . . . . . . . . . . . . . ...225 2 25 lb-in
(25 k 2.8 Nm) (2.59 ? 0.29 kg-m)

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5 Engine Auxiliary Systems JD750 Crawler Bulldozer
0599-2 Specifications and Special Tools TM- 1136 (Apr- 79)

SPECIFICATIONS AND TORQUE VALUES-Continued

MOUNTING FRAME
1 - Engine isolator mounts cap screws torque
‘D’ grade . ... . . .. . . . 445 lb-ft
(603 Nm) (62 kg-m)
5T.3 ‘F’ grade . . ... . . . . . . . . 685 lb-ft
1
> (929 Nm) (95 kg-m)

E!
I :

T65355N

Fig. PEngine isolator Mount I

EXTERNAL FUEL SUPPLY SYSTEM

Fuel tank capacity .... .. . ... 73 gal.

(277 L)

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JD750 Crawler Bulldozer Disconnect Clutch 7
TM- 1136 (Nov-75) Clutch Controls 0715-l

Section 7
DISCONNECT CLUTCH
CONTENTS OF THIS SECTION

GROUP 0715 - CLUTCH CONTROLS Page

General Information .................... 0715-3
Removal ........... : .................. 0715-3
Repair ................................ 0715-3
Installation ............................. 0715-3

GROUP 0752 - CLUTCH ELEMENTS

General Information .................... 0752-l
Removal .............................. 0752-l
Repair ................................ 0752-l
Installation. ............................ 0752-3

GROUP 0799 - SPECIFICATIONS

AND SPECIAL TOOLS
Specifications and Torque Values
Clutch Elements . . . . . . . . . . . . . 0799-l
Special Tools
Clutch Elements . . . . . . . . . . . . . . . . . 0799-2

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7 Disconnect Clutch JD750 Crawler Bulldozer
0715-2 Clutch Con trots TM- 1136 (Nov-75)

Litho in U.S.A.
c

JD750 Crawler Bulldozer Disconnect Clutch 7

’ TM-l 136 (Feb-77) Clutch Controls 0715-3

Group 0715
CLUTCH CONTROLS
GENERAL INFORMATION

The engine disconnect clutch allows the engine to REPAIR

be disengaged from the splitter drive assembly for
Inspect the clutch disconnect linkage components
cold weather engine starting.
(Figs. 1 and 2) for bent or worn condition.

As the clutch control lever is pulled upward, the

Check pivot points and headed pins for excessive
clutch cable actuates the control linkage rotating the
wear.
clutch fork shaft. This forces the release bearing for-
ward against the pressure plate release levers. The
Inspect cable for bent or worn condition. Check ca-
clutch release levers retract the clutch pressure
ble to see that it operates freely.
plate, releasing the driven disk from the pressure
plate and driving surface of the flywheel, thus discon-
Replace worn or damaged parts as needed.
necting the engine from the splitter drive assembly.
INSTALLATION
IMPORTANT: Instruct the operator to engage
the engine disconnect clutch slowly after the en- If clutch shaft was removed from clutch housing,
gine has started and warmed up. install clutch shaft and index lever horizontal towards .,. ,.
the front.
REMOVAL
Install parts using Figs. 1 and 2 as guides.
Disassemble clutch control linkage using Figs. 1
and 2 as guides.
Adjust disconnect clutch linkage so that approxi-
matelv 2 inches (51 mm) of control lever travel is
required to bring ‘throwout bearing in contact with
clutch release levers. Refer to Group 9020.
ia

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7 Disconnect Clutch JD750 Crawler Bulldozer
0715-4 Clutch Con fro/s TM- 1136 (Feb-77)

T'44130N

l--Spring Pin 7-Bell Crank 13-Control Cable

2-Lever 8-Spring Pin U-Pivot
3-Cotter Pin 8-Cotter Pin (4 used) 15-Pivot Pin
4-Rod lo--Pin (4 used) M-Cap Screw
ll-Adjustable End Yoke (3 used) 17-Bell Crank
12-Grommet l&End Rod

Fig. l-Clutch Disconnect Linkage (With Cab)

Litho in U.S.A.
JD750 Crawler Bulldozer Disconnect Clutch 7
TM- 1136 (Nov-751 Clutch Controls 0715-5

t1’
‘\ o/‘cb/”
e 14’
& *
0
0 F8

15’ Q %3

9’ 8 8”
/8
0 % 93

12 /YJ 13’

l-Lever GSpring Pin 1 l-Pivot

2-Gap Screw (2 used) ‘I--Cotter Pin (4 used) 12-Pivot Pin
3-Washer (2 used) &Pin (4 used) 13-Cap Screw
4-Lever Stop g-Adjustable -End Yoke (3 used) 14-Bell Crank
5-Bell Crank 1 g-Control Cable 15--End Rod

Fig. P-Clutch Disconnect Linkage (Without Cab)

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7 Disconnect Clutch JD750 Crawler Bulldozer
0715-6 Clutch Controls TM- 1136 (Nov-75)

bitho in U.S.A.
 JD750 Crawler Bulldozer Disconnect Clutch 7
TM- 1136 (Feb-77) Clutch Elements 0752-l

Group 0752
CLUTCH ELEMENTS
GENERAL INFORMATION
The engine disconnect clutch allows the engine to
be disconnected from the splitter drive for cold
weather starting.

The engine disconnect clutch is a simple dry-disk

assembly mounted on the engine flywheel. The
clutch disk is held in engagement by clutch springs.

When the disconnect clutch is engaged, engine

power is transmitted from the engine crankshaft to
the transmission via the splitter drive.
,
, -> IMPORTANT: Instruct the operator to engage
the engine disconnect clutch slowly after the en-
gine has started and warmed up.
.*

REMOVAL
Refer to Section 4, Group 0401 and remove the
engine. l-Driven Disk 3-Pressure Plate
P-Flywheel 4-Gap Screws (6 used)

Fig. l-Disconnect Clutch Elements

REPAIR
Remove cap screws (4, Fig. 1) to remove pressure
plate (3) and driven disk (1) from engine flywheel (2).

Litho in U.S.A.
7 Disconnect Clutch JD750 Crawler Bulldozer
0752-Z Clutch Elements TM-1 136 (Feb-77) L
&
Assembly
Press bushings (19, Fig. 3) in clutch housing flush
with bore. ,

Press bushings (19) in clutch housing flush with

bore.

Install release bearing (13), with largest outside di-

ameter facing flywheel, on clutch release bearing
carrier (14). Rotate bearing while assembling to car-
rier.

Use an old input shaft or a clutch aligning tool

(JDE 52) when installing driven disk (12) and pres-
sure plate (11).

Install driven disk with long hub away from fly- *

wheel. !’
l-Clutch Shaft !&Clutch Fork Shaft
2-Coupling 8-Clutch Fork
Align driven disk with input shaft bearing when in-
3-Gap Screws (3 used) 74nput Shaft
stalling pressure plate.
4-Clutch Fork 8-Release Bearing
Support g--Spring Pin (2 used)
Install pressure plate-to-flywheel cap screws (10).
Fig. 2-Disconnecf Clutch Assembly
NOTE: The clutch pressure plate release levers are
Disconnect spring (15, Fig. 3) from bearing carrier factory set, and no further adjustment should be made. I
(14) and pump cover.
Assemble clutch housing to splitter housing.
Remove bearing carrier (14) and release bearing
from pump cover. Remove release bearing (13) from Install clutch fork assembly in clutch housing and
bearing carrier. clip (22) to splitter housing.

Remove clip (22) from splitter housing and pull Clutch shaft (21) should operate freely after as-
clutch shaft (21) from clutch housing. sembly.

Remove cap screws (3, Fig. 2) and remove clutch Hole in lever on clutch shaft (21) should be in hori-
fork assembly. zontal position towards the front of crawler.

Remove coupling (2) from clutch fork shaft (5).

If clutch fork shaft (5), clutch fork (6) or clutch fork

support need servicing, drive spring pins (9) out of
clutch fork.

To remove clutch housing (20, Fig. 3) from splitter

housing, remove cap screws (18). Pull clutch housing
from splitter housing.

inspects parts for cracks, wear or other damage.

Replace parts as necessary.

Litho in U.S.A. - 7 - ”

;
h
/ JD750 Crawler Bulldozer Disconnect Clutch 7
TM-1 136 (Nov-75) Clutch Elements 0752-3

15’--

26

T44132N

l-Cap Screw (2 used) 1 l-Pressure Plate 28-Clutch Housing

a--Lock Washer (18 used) 12--Driven Disk 21-Clutch Shatt
3-Washer (2 used) 13-Release Bearing 22-Clip
4-Clutch Fork Support 14-Clutch Release 23-Cap Screw (4 used)
!5--Lock Washer (7 used) Bearing Carrier 24-Special Washer (4 used)
6-Gap Screw (3 used) 1%Spring 26-Clutch Housing Support
7-Clutch Fork Shaft 16Coupling 26Cap Screw (9 used)
8-Clutch Fork 17-Retaining Ring 27-Clip
9-Spring Pin (2 used) 18-Gap Screw (4 used) P&-Washer
l6-Special Screw (6 used) l9-Bushing (2 used) 29-Cap Screw

Fig. 3-Clutch Housing and Engine Disconnect

INSTALLATION
Join clutch housing and splitter housing to engine.

Refer to Section 4, Group 0401 and install engine,

clutch housing and splitter housing in crawler as a
unit.

Connect drive shafts to drive hubs.

Litho in U.S.A.
7 Disconnect Clutch JD750 Crawler Bulldozer
0752-4 Clutch Elements TM-1 136 (Nov-75)

Litho-iF71S.A.
 JD 750 Crawler Bulldozer Disconnect Clutch 7
TM- 1136 (Feb-77) Specifications and Special Tools 0799-l

Group 0799
SPECIFICATIONS AND SPECIAL TOOLS
CLUTCH CONTROLS
SPECIFICATIONS AND TORQUE VALUES

1 - Clutch control lever

free travel . . . . .. . .2 inches
(51 mm)

...A..,
"6
:i
T48495N

!*
Fig. I-Clutch Control Lever

CLUTCH ELEMENTS
SPECIFICATIONS AND TORQUE VALUES

1 - Press bushings flush with bore in clutch housing.

-_

T43685N

Fig. P-Clutch Housing Bushings

Litho in U.S.A.
 7 Disconnect Clutch JD750 Crawler Bulldozer
0799-2 Specifications and Special Tools TM- 1136 (Feb-77)

CLUTCH ELEMENTS
SPECIAL TOOLS
Essential Tools

Tool Tool No Use

JDE-52 Used to properly line up clutch

disk.

Fig. 34Jniversal Clutch Aligning Set

_‘m.

.---.
- x

.- _ :

:.

Litho in U.S.A.
JD750 Crawler Bulldozer Transfer Drive 0
TM- 1136 (Apr- 79) Housings and Covers 0841-l

Section 8
TRANSFER DRIVE
CONTENTS OF THIS SECTION

Page Page
GROUP 0841 - HOUSINGS AND GROUP 0899 - SPECIFICATIONS AND
COVERS SPECIAL TOOLS
Specifications and Torque Values
General Information . ................... 0841-3 Gears, Shafts, Bearings . . . . . . . . . . , . 0899-l
Removal . . . . . . . . . . . ................... 0841-3 Special Tools
Repair . . . . . . . . . .. .... ....... .. 0841-4 Gears, Shafts, Bearings . . . . . . . . . 0899-2 I
Installation . . . . . . . ......... ......... 0841-4

GROUP 0851 - GEARS, SHAFTS,

BEARINGS
General Information . . . . . . . . . . . . .... .. 0851-l
Removal .... ........... .. ....... 0851-l
Repair . . . _. . . _. . . . . . . . ... .. 0851-2
Installation . . . . . . . _. _ . . . . . ....... 0851-6

Litho in U.S.A.
 8 Transfer Drive JD750 Crawler Bulldozer
0841-2 Housings and Covers TM- 1136 (Apr- 79)

-..-
. .,
.:- .

Litho in U.S.A.
JD750 Crawler Bulldozer Transfer Drive 8
TM-1 136 (Nov-75) Housings and Covers 0841-3

Group 0841
HOUSINGS AND COVERS
GENERAL INFORMATION REMOVAL
The splitter housing, located at the rear of the en- Refer to Section 4, Group 0401 and remove en-
gine, contains the necessary gears and shafts to gine, disconnect clutch housing and splitter housing
transmit power from the engine to the left and right as an assembly.
transmissions.
Separate clutch housing from engine and splitter
The splitter housing bolts directly to the rear of the housing from clutch housing.

I
engine.
Refer to Section 8, Group 0851 and remove gears,
shafts and bearings.

3-

I 0

T43b'lON

l-Cap Screw (2 used) GSplitter Housing Drain Plug ll-Cap Screw (3 used)
2-Lock Washer (2 used) 745plitter Housing Oil Strainer Screen 12-Flat Washer (6 used)
3-Filler Dipstick Tube &Aluminum Washer 13-Clamp
4-Dipstick g-Oil Strainer Plug M-Hex. Nut (3 used)
5-O-Ring IO-Splitter Housing 16--T&e Support

fig. 1-Splitfer Housing

Litho in U.S.A.
8 Transfer Drive JD750 Crawler Bulldozer
0846 -4 Housings and Covers TM- 1136 (Nov- 75)

REPAIR INSTALLATION
inspect filler dipstick tube (3, Fig. 1) for bent or Refer to Section 8, Group 0851 and install gears,
worn condition. shafts and bearings.

Remove strainer screen (7) and clean thoroughly. Join clutch housing to splitter housing and clutch
Inspect for worn condition. housing and splitter housing to engine.

Clean and inspect splitter housing (10) for wear, Refer to Section 4, Group 0401 and install engine,
cracks or other damage. clutch housing and splitter housing in crawler as a
unit.
Replace parts as needed.

Apply Loctite Plastic Gasket or an equivalent to

surface of splitter housing and filler dipstick tube be-
fore assembly.

Lubricate O-ring (5) with the same type of oil that

will be used in splitter housing to prevent O-ring from
damage during installation.

Litho in U.S.A.
JO750 Crawler Bulldozer Transfer Drive 8
TM-l 136 (Nov-75) Gears, Shafts, Bearings 0851-l

Group 0851
GEARS, SHAFTS, BEARINGS
GENERAL INFORMATION
The splitter drive gear box provides for indepen-
dent drive to each transmission and one for main hy-
draulic pump.

Drive is also provided for an auxiliary pump and for

an engine driven winch drive in line with engine
crankshaft.

A small internal gear pump driven off the input

shaft in splitter drive provides forced lubrication.
Drilled passage-ways in the shafts and cored pas-
sages in splitter housing allow oil to be directed to
the bearings.

REMOVAL
Refer to Section 4, Group 0401 and remove en-
gine, clutch housing and splitter housing from crawler l-Splitter Housing !%Output Shaft (2 used)
as a unit. 2-Pump Drive Shaft &Idler Shaft Quill
Quill P-Cover
Separate clutch hcusing and splitter housing from 3-Filler Dipstick 8-Winch Drive
T&f? g-Plug
engine.
4-Dipstick

Separate clutch housing from splitter housing. Fig. l-splitter Housing

Litb in U.S.A.
8 Transfer Drive JD750 Crawler Bulldozer
0851-2 Gears, Shafts, Bearings TM-1 136 (Nov-75)

REPAIR

B
142041
l-Oil Seal 8-O-Ring 15-Oil Seal
2-Bearing Cup 8-Input Shaft Quill 18-Pump Cover with Seal
3-Bearing Cone lo--Lock Washer (7 used) 17-Sealing Ring
4-Input Shaft 1 l-Cap Screw (7 used) l&Oil Pump Gear
5-Bearing Cone 12-Cap Screw (4 used) l(b-Woodruff Key
GBearing Cup 13-Lock Washer (4 used)
7-Shim (as required) 14-Pump Cover

Fig. Z-Splitter Housing Input Shaft

Remove cap screws (11, Fig. 2) securing input Remove cap screws (5, Fig. 4) securing idler shaft
shaft quill (9) to splitter housing. Remove input shaft quill (7) and pump drive shaft quill (8) to splitter
quill, input shaft and bearings. housing. Remove quills, idler gear (13), pump drive
gear (12) and bearings.
Remove cap screws (12) securing pump cover
(14) to input shaft quill. Remove pump cover, sealing Remove O-rings from quills. Remove oil seals from
ring (17) and oil pump gears (18). splitter housing if required. Pull bearings from shafts.

Remove cap screws (12, Fig. 3) securing output

shaft quill (10) to splitter housing. Remove output
shaft quill, output shaft and bearings.

Litho in U.S.A.
 JD750 Crawler Bulldozer Transfer Drive 8
TM-1 136 (Nov-75) Gears, Shafts, Bearings 0851-3

l-Shaft Rear Seal 6-Output Shaft 9-Shim (as required)

2-Splitter Housing GBearing Cone 19-Output Shaft Quill
3-Bearing Cup 7-Bearing Cup 11-Lock Washer (6 used)
4-Bearing Cone &O-Ring t2-Cap Screw (6 used)

Fig. b-Right-Hand and Left-Hand Drive Gears

22
T42042

l-Cap Screw (2 used) 6-Lock Washer (16 used) ll-Bearing Cone (4 used)
2-Lock Washer (2 used) 7-Idler Shaft Quill 12-Pump Drive Gear
a--Pump Cover 8-Pump Drive Shaft Quill 13-Idler Gear
4-Pump Seal g--Shim (as required)
5-Cap Screw (16 used) ltl-Bearing Cup (4 used)

Fig. 4-Pump Drive Gear and Idler Gear Assembly

Litho in U.S.A.
 8 Transfer Drive JD750 Crawler Bulldozer
08514 Gears, Shafts, Bearings TM- I 136 (Nov- 75)

Refer to Figures 2, 3 and 4 for disassembly and Inspect bearings for scored, pitted, scratched,
assembly of parts. cracked or chipped races, and for indication of ex-
cessive wear of rollers or balls. If one of these de-
All parts must be cleaned to permit effective in- fects is found, replace the bearing.
spection
Inspect the defective bearing housing and shaft for
All metallic parts (except bearings) should be grooved, burred, or galled conditions that indicate the
cleaned thoroughly with mineral spirits, or by the bearing has been turning in its housing or on its
steam-cleaning method. Do not use a caustic soda shaft. If the damage cannot be repaired with crocus
solution for steam cleaning. Gum and varnish depos- cloth, replace the defective part.
its should be removed by allowing the parts to soak
in varnish remover. Inspect lip-type oil seals. It is good practice to in-
stall new oil seals if splitter housing is completely
Parts should be dried with compressed air. Steam- disassembled.
cleaned parts should be oiled immediately after
drying. When replacing lip-type oil seals make sure the lip
of each oil seal is toward the oil to be sealed (toward
Aft%Meaning, examine the parts to make certain the inside of the unit). If seal is not coated on outside
they are entirely clean. Reclean them, if necessary. surface, use a nonhardening sealing compound on
the outside of the seal to help prevent oil leaks. Coat
Bearings that have been in service should be thor- the inside of the seal with high temperature grease
oughly washed in mineral spirits. (AT30408 or equivalent) to protect the seal during
shaft installation and to provide lubrication during ini-
If the bearings are particularly dirty, soak them in tial operation.
the spirits before trying to clean them.
Inspect gears for scuffed, nicked, burred, or broken
Before inspection, oil the bearings with the same teeth. If the defect cannot be removed with a soft
type of oil that will be used in the splitter housing. honing stone, replace the gear.

Inspect bearings for roughness of rotation. Replace Inspect gear teeth for wear that may have de-
a bearing if its rotation is still rough after cleaning stroyed the original tooth shape. If this condition is
and oiling. found, replace the gear.

Inspect the thrust faces of gears for scores,

scratches, and burrs. Remove such defects with a
soft honing stone.

Lubricate all O-rings with the same type of oil that

will be used in the splitter housing to prevent O-rings
from cutting during installation.

-Litho in U.S.A.
JD750 Crawler Bulldozer Transfer Drive 8
TM- 1136 (Apr- 79) Gears, Shafts, Bearings 0851-5

Install oil seal (1, Fig. 2) over input shaft and flush to
-.-
outside surface of splitter housing.

Install Woodruff key (19) and pump gear (18) over

input shaft and into position.
_-~-
Install sealing ring (17) and pump cover with seal.

Install pump drive gear (12, Fig. 4) with bearings

(11) into splitter housing.

Install enough shims (9) to obtain measurable end

play. Install pump drive shaft quill (8) and securely
l-JDG-44 Disk 3-Pump Cover tighten cap screws (5).
2-Oil Seal e-O.276 2 0.020 in.
(7.01 2 0.51 mm)
Measure end play on pump drive gear with the shaft
Fig. 5lnstding Oil Seal in Pump Cover
in a vertical position. Add or subtract shims (9) to
provide 0.001 to 0.004 inch (0.03 to 0.10 mm) end play.
Assemble a JDG-44 disk (1, Fig. 5) to a drive handle
and install oil seal (2) spring side out, in pump cover Following the same procedure, install idler gear (13)
(3). Install seal to a depth of 0.276 + 0.020 inch (7.01 and adjust end play to 0.001 to 0.004 inch (0.03 to 0.10
2 0.51 mm) from face of seal to outer edge of cover mm) end play.
(4).
NOTE: Make sure idler gear and pump drive gear
Press bearing cups in splitter housing or bearing internal splines are toward the rear of the splitter
quills. housing.

Heat bearings in dry heat not to exceed 250°F Install output shaft (5, Fig. 3) with bearings (4 and 6)
(121 “C) before assembly. into splitter housing.

Press bearings on shafts to seat firmly. Install enough shims (9) to obtain measurable end
play. Install output shaft quill (lo), without O-ring (8)
Install input shaft (4, Fig. 2) with bearings (3 and 5) and securely tighten cap screws (12).
into splitter housing.
Measure end play on output shaft with the shaft in a
NOTE: The bearing end play adjustment must be vertical position. Add or subtract shims (9) to provide
made with the shafts in the vertical position in order to 0.001 to 0.004 inch (0.03 to 0.10 mm) end play.
obtain an accurate reading.
After correct shim pack is determined, install O-ring
Install enough shims (7) to obtain measurable end (8) on output shaft quill (10).
play. Install input shaft quill (9), without O-ring (8) and
securely tighten cap screws (11). Install shim pack and quill and secure with cap
screws.
Measure end play on input shaft with the shaft in a
vertical position. Add or subtract shims (7) to provide Install oil seal (1) over output shaft and flush to
0.001 to 0.004 inch (0.03 to 0.10 mm) end play. outside surface of splitter housing.

After correct shim pack is determined, install O-ring Use this procedure to install right and left output
(8) on input shaft quill. shafts.

Install shim pack and quill and secure with cap

screws.

Litho in U.S.A.
8 Trasnfer Drive JD750 Crawler Bulldozer
0851-6 Gears, Shafts, Bearings TM- 1136 (Apr- 79)

INSTALLATION
Join splitter housing to clutch housing.

Join splitter housing and clutch housing to engine.

Refer to Section 4, Group 0400 and install splitter

housing, clutch housing and engine in crawler as a
unit.

Litho in U.S.A.
JD780 C&wler Bulldozer Transfer Drive 8
TM- 1136 (Apr- 79) Specifications and Special Tools 0899-l

Group 0899
SPEClFlCATiONS AND SPECIAL TOOLS
GEARS, SHAFTS, BEARINGS
SPECIFICATIONS AND TORQUE VALUES

1 - Distance oil seal is pressed below

surface of pump cover . . . . .0.276 + 0.020 in.
(7.01 + 0.51 mm)

566966
Fig. I-Pump
d1
Cover Oil Seal

1 - Pump drive gear and

idler gear end play. . . . . . . . 0.001 to 0.004 in.
(0.03 to 0.10 mm)

NOTE: End play must be measured with the shafts

in a vertical position.

Fig. P-Pump Drive Gear and Idler Gear

Litho in U.S.A.
8 Transfer Drive JO750 Crawler Bulldozer
0899-2 Specifications and Special Tools TM- 1136 (Apr- 79)

GEARS, SHAFTS, BEARINGS

SPECIFICATIONS AND TORQUE VALUES-Continued

1 - Left and right output

shaft end play . . . . . . . . . 0.001 to 0.004 in
(0.03 to 0.10 mm)

NOTE: End play must be measured with the shafts

in a vertical position.

T43814N

Fig. 3-Left and Right Output Shafts

1 - Input shaft endplay.. . . . . . 0.001 to 0.004 in

(0.03 to 0.10 mm)

NOTE: End play must be measured with the shafts

in a vertical position.

T43815N

Fig. 4-Input Shaft

SPECIAL TOOLS

Convenience Tools
TOOI Tool Number Use

JDG-44 To drive oil seal below surface of

pump cover to the specified dis-
tance. (Does not include handle or
bolt).

Fig. 5-Seal Driver

Litho in U.S.A.
JD750 Crawler Bulldozer Parking Emergency Brake 11
TM-1 136 (Nov-78) Active Elements 1111-l

Section 11
PARKING EMERGENCY BRAKE
CONTENTS OF THIS SECTION

Page
GROUP 1111 - ACTIVE ELEMENTS GROUP 1160 - PARKING BRAKE HYDRAULICS
General Information ................. 1111-3 General Information .... ........ ...... 1160-l
Removal ........................... 1111-3 Removal .............. ........ ...... 1160-2
Repair ............................. 1111-3 Disassembly ........... ........ ...... 1160-3
Assembly ........................... 1111-3 Repair ................ ........ ...... 1160-3
Installation .......................... 1111-5 Assembly. ............. ...... 1160-4
Installation ............. ...... 1160-4
GROUP 1115 - CONTROLS LINKAGE
General information . . . . . . . . . . . . . . 1115-1 GROUP 1199 - SPECIFICATIONS AND
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 1115-1 SPECIAL TOOLS
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . 1115-2 Specifications and Torque Values
installation. . . . . . . . . . . . . . . . . _. . . . . 1115-2 Active Elements. . . . . . . . . . . . . . 1199-l
Brake Valve Cable Adjustment . . . . 1115-3 Hydraulic System . . . . . . . . . . . . 1199-2

Litho in U.S.A.
 11 Parking Emergency Brake JD750 Crawler Bulldozer
1111-2 Active Elements TM-1 136 (Nov-78)

Litho in U.S.A.
JD750 Crawler Bulldozer Parking-Emergency Brakes 11
TM-l 136 (Nov-78) Active Elements 1111-3

Group 1111
ACTIVE ELEMENTS
General Information Remove cap screws (7 and 8), disk cover (6), plan-
etary brake disks and planetary brake separator plates.
The parking brakes are located in the final drive
housings. They are of the spring applied and hydraulic
Tighten two cap screws, installed in tapped holes
release type.
(l), evenly to compress springs until snap ring (4) can
be removed from brake piston (3).
Removal
Refer to Section 2, Group 0201 and remove final Evenly back out cap screws until spring pressure is
drive housing assembly from crawler. relieved.

Drain oil from final drive housing. Remove two cap screws, brake plate (5) springs,
brake housing and brake piston (3).
Repair
Inspect brake hub (11, Fig. 2) for scuffed, nicked,
Remove brake hub from final drive shaft.
burred, or broken teeth. If the defect cannot be re-
moved with a soft honing stone, replace the hub.

Check springs (8) for proper strength. Free length is

2.980 ? 0.060 inches (75.69 ? 1.52 mm). With 131 to
151 Ibs. (583 to 672 N) (59 to 69 kg) compressive load
length should be 2.04 inches (51.8 mm).

Assembly
Lubricate dowel pin holes in brake housing (7, Fig.
2) before pressing in dowel pins (6) if removed. Press
dowel pins in brake housing so that they protrude 0.55
inch (14 mm) outside of brake housing.

Lubricate O-rings (3, 4 and 5) before installing on

brake piston or brake housing.

Assemble brake piston (2) in brake housing (7)

being careful not to damage O-ring (3 and 4). Install
springs (8) and brake plate.

1 -Tapped Hole Crake Plate

2-Final Drive Housing 8-Disk Cover
IBrake Piston 7-Gap Screw (8 used)
4-Snap Ring 8-Gap Screw (4 used)

Fig, I-Removing Parking Brake Elements

Install two 3/8-16 UNC-2Ax l-l /2 cap screws in

holes (1, Fig. 1) to relieve spring pressure on planetary
brake disks and planetary brake separator plates.

Litho in U.S.A.
11 Parking-Emergency Brakes JD750 Crawler Bulldozer
1111-4 Active Elements TM-l 136 (Nov-78)

FINAL DRIVE

T44042

l-Spacer 7-Brake Housing O-Planetary Brake Separator

2-Brake Piston Spring (16 used) Plate (3 used)
3-O-Ring g-Brake Plate M-Disk Cover
4-GRing 1 O-Snap Ring 16-Lock Washer (8 used)
!&O-Ring (2 used) 11-Brake Hub %-Cap Screw (8 used)
6-Dowel Pin (2 used) la--Planetary Brake Disk (4 used) 17-Lock Washer (4 used)
18-Gap Screw (4 used)

Fig. FParking Brake Assembly

Install two 3/8-16 UNC 2-Axl-l/2 cap screws Install disk cover (14) and secure with cap screws
through brake plate and thread into brake housing to (16 and 18).
compress springs until snap ring (10, Fig. 2) can be
NOTE: If any parts in the final drive shaft assembly,
installed. Remove the two cap screws.
the spacer (1, Fig. 2) or the parking brake hub (11) are
install brake housing assembly into final drive replaced, a check must be made to insure that the
housing being careful not to damage O-rings (5). center surface of the brake hub is below the milled
surface of the final drive housing. If the center surface
install spacer (1) and brake hub (11) on final drive
of the brake hub is not below the milled surface of the
shaft.
final drive housing, it will preload the bearings, result-
Install one planetary brake disk over brake hub and ing in bearing failure. Use the following procedure to
against brake plate. check.
Alternately install three planetary brake separator
plates (13) and the remaining three planetary brake
disks The last plate installed is a planetary brake disk.

Litho in U.S.A.
JD750 Crawler Bulldozer Parking- Emergency Brakes 11
TM- 1136 (Nov-78) Active Elements 1111-5

T484931

l--Milled Surface on Final Drive Housing 4-Brake Hub

Which Bolts to Transverse Case 5-Brake Hub Surface
24.002 to 0.0030 Inch (0.05 to 0.76 mm) 6-JD-264 Tool
Clearance 7-l Inch (25 mm) Metal Block
d--Spacer

Fig. 3-Clearance Measurement

Clamp a 1 inch (25 mm) thick block of metal (7, Fig. If the clearance is less than 0.002 inch (0.05 mm),
3) (or 1 inch x 1 inch [25 x 25 mm] piece of angle iron) material must be removed from the end of spacer (3) to
to the center leg of a JD-264 Clutch Tool (6). To ensure 0.002 to 0.030 inch (0.05 to 0.76 mm) clear-
position the metal block correctly, stand the JD-264 ance.
Clutch Tool on a flat level surface. Stand the metal on
the same surface and clamp to the tool with a small Remove spacer.
C-clamp or a locking plier.
Grind or file spacer as required. BE SURE square-
Set the tool on the milled surface on the final drive ness of spacer is maintained. DO NOT grind at an
housing (1). The tool is not long enough to span the angle.
!
final drive opening but will be enough to make clear-
ance check. Reinstall spacer and recheck clearance. )
I
1
Push the brake hub (4) completely in. Installation
Refer to Section 2, Group 0201 and install final drive _
Check for clearance (2) between metal block and
assembly to crawler.
brake hub surface (5) at three places with a feeler
gauge.
Refer to Section I and fill final drive housing with l
recommended type and quantity of oil.

Litho in U.S.A.
11 Parking Emergency Brakes JD 750 Crawler Bulldozer
1111-6 Active Elements TM- 1136 (Nov-78)

Litbo in U.S.A.
JD 750 Crawler Bulldozer Parking Emergency Brake 11
TM- 1136 (Nov-78) Controls Linkage 1115-l

Group 1115
CONTROLS LINKAGE
GENERAL INFORMATION REMOVAL
Let out any hydraulic pressure by loosening a fitting.

Remove and cover hydraulic lines.

Remove nut (1, Fig. 2) and lock washer (2).

Remove ball joints (3) from control cable (5).

Remove cap screws (7 and 8), cable anchor (6),

pipe spacers (la), and lock washers (2);

Remove brake release valve.

Remove nut (16), lock washer (15), lever mounting

bracket (14), washer (19), bushing (13), and cap screw
(9).

l-Control Handle 3-Brake Release Pump

P-Brake Release Valve 4-Brake Valve Plunger
Handle

Fig. l-Brake Valve

The location of the brake valve linkage is below the

floor board. The linkage connects the parking brake
pedal to the brake valve; the brake valve controls the
operation of the parking brakes.

Litho in U.S.A.
 11 Parking Emergency Brake JD750 Crawler Bulldozer
1115-2 Controls Linkage TM-l 136 (Nov-78)

., _-‘I ‘. :. f,
;;. : ,.,. .;:, ‘d’i
BRAKE-...” ..-..--* --3

ARM

VALVE

T61721N

l-Nut g-Cap Screw M-Lever Mounting Bracket 20-Brake Lever

2-Lock Washer (3 used) 9-Gap Screw 15-Lock Washer Ii-Spacer
3-Ball Joint (2 used) 1 O-Pin 18-Nut 22-Washer
4-Band (4 used) Ii-Cotter Pin 17-Jam Nut (2 used) 23-Gap Screw
8-Control Cable 12-Brake Release Pump 18-Pipe Spacer (2 used)
8-Gable Anchor Handle Is-Washer
7-Gap Screw 13-Bushing

Fig. Z-Brake Valve Linkage

Remove cotter pin (11, Fig. 2), pin (IO), and brake Inspect ball joints (3) and bushing (13) for wear.
release pump handle (12).
Replace badly worn and damaged parts.
Remove cap screw (23), washer (22), brake lever
.ml (20), and spacer (21). INSTALLATION
Install ball joints (3) on control cable (5).
REPAIR
Inspect control cable (5) for bends or breaks. Install brake release pump handle (12), pin (1 O), and
cotter pin (11) on to the brake valve.

Litho in U.S.A.
 JD750 Crawler Bulldozer Parking Emergency Brake 11
TM-1 136 (Nov-78) Controls Linkage 1115-3

Install cap screw (9, Fig. 2), bushing (13) and

washer (19):

install lever mounting bracket (14), lock washer (15)

and cap screw.

Install brake lever (20), spacer (21), washer (22),

and cap screw (23).

Install brake valve in unit.

Install cable anchor (6), cap screw (7), pipe spacer

(18), and lock washer (2).

Install cap screw (8), pipe spacer (18), and lock

washer (2).

Connect ball joint (3) to brake arm.

1 See Page 9026-105 for adjustment.

Install nut (1) and lock washer (2) to ball joint (3).

Tighten control cable nuts on to cable anchor (6).

Litho in U.S.A.
11 Parking Emergency ‘Brake JD750 Crawler Bulldozer
1165-4 Controls Linkage TM-1 136 (Nov-78)

Litho in U.S.A.
JD750 Crawler Bulldozer Parking Emergency Brake 11
TM- 1136 (Apr- 79) Controls Linkage 1115-5

Install cap screw (9, Fig. 2), bushing (13) and

washer (19).

Install lever mounting bracket (14), lock washer (15)

and cap screw.

Install clip (20) washer (22), and cap screw (23).

Install brake valve in unit.

Install cable anchor (6), cap screw (7), pipe spacer

(18), and lock washer (2).

Install cap screw (8) pipe spacer (18), and lock

washer (2).

Connect ball joint (3) to brake arm.

Install nut (1) and lock washer (2) to ball joint (3).

Tighten control cable nuts on to cable anchor (6). , l-Cap Screw 3-Brake Valve Plunger
,’
2-Adjusting Clip 4-Plunger Nut

Fig. 3-Brake Valve Linkage

Litho in U.S.A.
11 Parking Emergency Brake JD750 Crawler Bulldozer
1115-6 Controls Linkage TM- 1136 (Apr-79)

Litho in U.S.A.
JD750 Crawler Bulldozer Parking Emergency Brake 11
TM- 1136 (Nov-75) Parking Brake Hydraulics 1160-l ;

Group 1160
PARKING BRAKE HYDRAULICS

l-Sump Port 4-Charge Pressure Port

2-Parking Brake Port 5-Brake Valve
3-Transmission Bypass Port

Fig. l-Brake Valve Location

GENERAL INFORMATION To release the brakes without running the engine,

install cap screw, threaded rod, or steel rod into brake
The parking brakes are between the right and left
release pump handle (12, Fig. 2). Operate brake re-
transmissions and the final drives. The parking brakes
lease pump handle three to four times and the brakes
are spring engaged and hydraulically released. The
should release.
brake valve directs transmission charge pressure oil to
release the brakes and close the transmission bypass
NOTE: If during transport the brakes are activated,
valve. If the transmission charge pressure drops below
it will be necessary to operate the brake release pump
100 psi (7 bar) (7 kg/cm2), the brake valve will direct
handle again.
the parking brake pressure oil to sump. The parking
brakes will engage.

Litho in U.S.A.
 11 Parking Emergency Brake JD 750 Crawler Bulldozer.
1160-2 Parking Brake Hydraulics TM- 1136 (Nov-75)

17
T44733

l-Nut S-Cap Screw U-Lever Mounting Bracket Pl-Brake Lever

2-Lock Washer (3 used) g-Cap Screw 15-Lock Washer 22-Washer
3-Ball Joint (2 used) lo--Pin 16-Nut 23-Cap Screw
4-Band (4 used) 1 l-Cotter Pin 17-Jam Nut (2 used) 24-Spacer
5-Control Cable 12-Brake Release Pump 16-Pipe Spacer (2 used) 25-Washer
6-Cable Anchor Handle 19-Washer 26Cap Screw
7-Cap Screw U-Bushing 2O-Clip

Fig. P-Brake Valve Linkage

See Section 90 Group 9026 for more information on Remove cotter pin (11) and pin (10).
the parking brake operations.
Remove cap screw (8), cap screw (7), cable anchor
REMOVAL (6), pipe spacers (18), and lock washers (2).
Let out any hydraulic pressure by loosening a fitting.
Remove and cover hydraulic lines.

Remove cap screw (26, Fig. 2), washer (25) and

spacer (24).

Litho in U.S.A.
JO750 Crawler Bulldozer Parking Emergency Brake 11
TM- 1136 (Nov-75) Parking Brake Hydraulics 1160-3

28

144887.11

l-Plug g--Retaining Ring 18-O-Ring 27-Back-up Washer

2-Back-up Washer l&Dust Cover Boot M-Spring 28-Plug
3-O-Ring 1 l--Plug 20-Brake Poppet Valve 2g-Plug
4-Spring 12-Back-up Washer 21-Ball 30-Back-up Washer
5-Shuttle Valve 13-O-Ring 22-O-Ring 31-O-Ring
GSpring M-Safety Plunger 23-Release Seat 32-Spring
7-Manual Brake Release 15-Spring 24-Release Plunger 33-Lift Check
Spool lb-Plug 2!%-0-Ring 34-Lockout Seat
&Washer 17-Back-up Washer 26-O-Ring 35-O-Ring

Fig. 3-Brake Valve Assembly

DISASSEMBLY Remove plug (16), back-up washer (17), O-ring

(18), and spring (19).
Remove plug (1, Fig. 3), back-up washer (2) O-ring
(3), spring (4), and shuttle valve (5).
Remove brake poppet valve (20), ball (21) O-ring
Remove dust cover boot (lo), retaining ring (9), and (22) and release seat (23).
washer (8).
Remove plug (28), back-up washer (27), O-ring
Remove manual brake release spool (7) and spring
(26), O-ring (25), and release plunger (24).
(6).
REPAIR
q
Remove plug (29), back-up washer (30), O-ring
(31), and spring (32).
Insoect shuttle valve (5), manual brake release
Remove lift check (33), lockout seat (34) and O-ring spool.(7), and brake poppet valve (20). If any of the
(35). valves have a defect, replace complete brake valve
assembly.
Remove plug (il), back-up washer (12), O-ring
(13), safety plunger (14), and spring (15).
Clean valve with diesel fuel and dry with com-
pressed air.

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11 Parking Emergency Brake JD750 Crawler Bulldozer
1160-4 Parking Brake Hydraulics TM- 1136 (Nov-75)

IMPORTANT: Regular cleaning fluids are dam- Install O-ring (35, Fig. 3) on lockout seat (34).
aging to the transmission parts; use only diesel
fuel to clean the brake valve. Install lockout seat (34), lift check (33) spring (32)
and plug (29).
Check the following springs:
Install back-up washer (12) and O-ring (13) on plug
Brake release poppet valve spring (19, Fig. 3) (11).
Free length.. . . . . . . . . . . ~. 1.375 in. (34.9 mm)
Install spring (15) safety plunger (14) and plug (11).
Test length . . . . . . . . . . . . . 1.00 in. (25.4 mm)
with 13.5 to 14.5 lb. Install back-up washer (17), and O-ring (18) on plug
(60 to 65 N) (6 to 7 kg) (1%

Safety plunger spring (15) Install O-ring (22) on release seat (23).

Free length.. . ..... .0.956 in. (24.3 mm)

Install release seat (23) ball (21), brake poppet
Test length . . . . . . . . .0.625 in. (15.9 mm) valve (20) spring (19), and plug (16).
with 1 lb. (4 N) (7 kg)
Install back-up washer (27) and O-ring (26) on plug
Manual brake release spring (6) (28).
Free length. . . . . . . _. . . 1.732 in. (44 mm)
Install O-ring (25) on release plunger (24).
Test length . . . . . . _. . . .1.250 in. (31.8 mm)
with 29 lb. (129 N) (13 kg) Install release plunger (24) and plug (28).

Lift check spring (32) INSTALLATION

Free length. . . . . . . . . . . . .0.496 in. (12.6 mm) Install lock washers (2, Fig. 2) pipe spacers (18)
cable anchor (6), and cap screws (7 and 8).
Test length . . . . . . . . . ~. .0.437 in. (11.1 mm)
with 0.21 to 0.27 lb.
Install pin (10) and cotter pin (11).
(1.0 to 1.2 N) (0.09 to 0.12 kg)
Install spacer (24), washer (25), and cap screw (26).
Replace any parts with defects.
For adjustment of brake valve linkage, see Section
ASSEMBLY
11, page 1115-5.
Install back-up washer (2, Fig. 3) and O-ring (3) on
plug (1).
Install shuttle valve (5), spring (4) and plug (1).

Install spring (6), manual brake release spool (7)

washer (8), retaining ring (9), and dust cover boot (10).
Install back-up washer (30) and O-ring (31) on plug
(29).

Litho in U.S.A.
 JD750 Crawler Bulldozer Parking Emergency Brake 11
TM-1 136 (Nov-78) Specifications and Special Tools 1199-1

Group 1199
SPECIFICATIONS AND SPECIAL TOOLS
ACTIVE ELEMENTS
SPECIFICATIONS AND TORQUE VALUES
1 - Spring test length . . . . . . . . . . . . . . . . . .2.04 in.
(51.8 mm) with a 131 to 151 lb.
(583 to 672 N) (59 to 69 kg) force applied.
2 - Spring free length . . . . . . . . . . 2.980 & 0.060 in.
(75.69 r 1.52 mm)

Fig. l-Parking Brake Spring

1 - Dowel pins to protrude

from brake housing . . . . . . . . , . . . . . . .0.55 in.
(14 mm)

T44114N

Fig. BBrake Housing Dowel Pins

1 - Thickness of new parking

brake separator plate . . . . . . . 0.118 to 0.122 in.
(3.00 to 3.10 mm)

2 - Thickness of new parking

brake disk.. . . . . . . . . . . . . . 0.117 to 0.123 in.
(2.97 to 3.12 mm)

T44115N

Fig.3-Parking Brake Disks and Plates

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11 Parking- Emergency Brakes JD750 Crawler Bulldozer
1199-2 Specifications and Torque Values TM- I 136 (Nov- 78)

HYDRAULIC SYSTEM
SPECIFICATIONS AND TORQUE VALUES

1 - Safety plunger spring free length. . . . . .0.96 in.

(24.4 mm)

Test length . . . . . . . . . . . . . .0.63 in. (16.0 mm)

with a 3 lb. (13 N) (1.4 kg) load applied

2 - Brake poppet valve spring free

length . . . . . . . . . . . . . . . . 1.38 in. (35.1 mm)

Test length . . . . . . . . . .l.OO in. (25.4 mm)

with a 13.5 to 14.5 lb. (60 to 65 N)
(6 to 7 kg) load applied

3 _ Shuttle valve spring free

length . . . . . . . . . . . . .1.73 in. (43.9 mm)

Test length . . . , . . . . . .I.25 in. (31.8 mm)

with a 29 lb. (129 N) (13 kg) load applied

Fig. 4-Brake Valve

1 - Manual brake release spring

free length. . . . . . . . . . . .2.50 in. (63.5 mm)

Test length . . . . _. . . . _. _. . .2.13 in. (54.1 mm)

with a 5 lb. (22.3 N) (2.3 kg) load applied

2 - Lift check spring free length . . . . . . .0.50 in.

(12.7 mm]

Test length . . . . . . . . . . . .0.44 in. (11.2 mm)

with a 0.21 to 0.27 lb. (0.9 to 1.2 N)
(0.10 to 0.12 kg) load applied

Fig. 5-Manual Brake Release Spool

bitho in U.S.A.
JD750 Crawler Bulldozer Equipment Attaching 15
TM- 1136 (No v- 75) Drawbar 151 l-1

Section 15
EQUIPMENT ATTACHING
CONTENTS OF THIS SECTION

Page
GROUP 1511 - DRAWBAR
General Information . . ... .. . . . . . 151 l-3
Removal............................... 1511-3
Repair.. . . . . ... ... . . . . . . . . . 1511-3
Installation . .. . . ... . .. _. . 151 l-3

GROUP 1512 - TOWBAR

General Information .................... 1512-l
Removal. .............................. 1512-l
Installation ............................. 1512-l

Litho in U.S.A.
15 Equipment Attaching JD 750 Crawler Bulldozer
151 l-2 Drawbar TM-1 136 (Nov-75)

titho in U.S.A.
JD 750 Crawler Bulldozer Equipment Attaching 15
TM-1 136 (Nov-75) Drawbar 151 l-3

Group 1511
DRAWBAR
DRAWBAR Removal
To remove the drawbar from the unit, attach chain
General Information hoist to drawbar, remove cap screws (4, Fig. 1) and
The JD750 Crawler Bulldozer is equipped with a remove drawbar.
fixed drawbar.
Repair
Refer to Fig. 1 for disassembly and assembly of
drawbar.

Installation
Follow removal procedure in reverse order.

l-Left Drawbar Plate 8-Nut (4 used)

2-Right Drawbar Plate 9-Drawbar Pin
3-Lock Washer (6 used) lO-Cap Screw
4-Gap Screw (6 used) 1 l-Lock
6-Bolt (4 used) 12-Lock Washer
&Drawbar Jaw U-Nut
7-Lock Washer (4 used)

Fig. 1-Drawbar

Litho in U.S.A.
-45 Equipment Attaching JD750 Crawler Bulldozer
1511-4 Drawbar TM-1 136 (Nov-75)

Litho in U.S.A.
JD 750 Crawler Bulldozer Equipment Attaching 15
TM-1 136 (Nov-75) Towbar 1512-l

Group ‘1512
TOWBAR

T41691N

l-Nut (6 used) 3-Pull Hook

P-Lock Washer (6 used) 4-Gap Screw (6 used)

Fig. I-Pull Hook

General Information Installation

A pull hook is located in the front center of the unit Follow removal procedure in reverse order.
under the belly pan.

Removal
Remove 6 cap screws (4, Fig. 1) and remove
hook.

Litho in U.S.A.
15 Equipment Attaching JD 750 Crawler Bulldozer
1512-2 Towbar TM- 1136 (Nov- 75)

Litho in U.S.A.
JD750 Crawler Bulldozer Electrical Systems 16
TM-l 136 (Nov-78) Batteries, Supports and Cables 1671-l

Section 16
ELECTRICAL SYSTEMS
CONTENTS OF THIS SECTION .
q
Page Page
Group 1671 - Batteries, Supports and Cables Group 1674 - Wiring Harness and Switches
Batteries Wiring Harness
General information .................. 1671-3 General information .................. 1674-l
Removal ............................. 1671-4 Removal ............................. 1674-l
inspection ........................... 1671-4 Battery Disconnect
Testing .............................. 1671-5 General Information .................. 1674-2
Charging ............................ 1671-7 Removal. ............................ 1674-2
Installation ........................... 1671-7 Repair. .............................. 1674-2
Installation ........................... 1674-2
Group 1672 - Alternator, Regulator and Charging Circuit Breakers
System Wiring General Information .................. 1674-3
42 Amp Alternator and Regulator Removal. ............................ 1674-3
General Information ................ 1672-I Repair. .............................. 1674-3
Removal. .......................... 1672-2 Installation ........................... 1674-3
Repair. ............................ 1672-2 Fuses
Disassembly ..................... 1672-2 General Information .................. 1674-3
Alternator Component Tests. ........ 1672-7 Removal. ............................ 1674-3
Assembly. ........................ 1672-l 1 Repair. .............................. 1674-3
Test After Assembly. .............. 1672-12 Installation ........................... 1674-3
Installation ........................ 1672-I 2 Starting Circuit Relay
16 Amp Alternator and Regulator General Information .................. 1674-4
General Information ............... 1672-I 3 Removal. ............................ 1674-4
Removal. ......................... 1672-l 4 Repair .............................. 1674-4
Repair. ........................... 1672-l 5 Installation. .......................... 1674-4
Disassembly .................... 1672-l 5 Air Conditioning Relay ............... 1674-4
Alternator Component Tests ........ 1672-20 Start Safety Switch
Assembly ......................... 1672-23 General Information ............... 1674-4
Test After Assembly. .............. 1672-25 Removal ....................... 1674-4
Installation ........................ 1672-25 Repair.........................l674- 4
Installation ...................... 1674-4
Group 1673 - Lighting System
Lights Group 1699 - Specifications and Special Tools
General Information .................. 1673-I Specifications and Torque Values
Removal. ............................ 1673-I Batteries, Supports and Cables.. . . . . . . 1699-I
Repair. .............................. 1673-I Alternator, Regulator and Charging
Installation ........................... 1673-I System Wiring . . . . . . . . . . . . . . . . 1699-I
Light Switch Vehicle Lighting System . . . . . . . . 1699-4
General Information .................. 1673-2 Wiring Harness and Switches . . . . . . . 1699-4
Removal. ............................ 1673-2 Special Tools
Repair. .............................. 1673-2 Batteries, Supports and Cables. . . . . . . 1699-5 .
Installation ........................... 1673-2 Alternator, Regulator and Charging
System Wiring . . . . . . . . . . _. . . . . . . . . 1699-6

Litho in U.S.A.
16 Electrical Sys terns JD750 Crawler Bulldozer
1671-2 Batteries, Supports and Cables TM-1 136 (NOW78)

Litho in U.S.A.
JD750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Apr- 79) Batteries, Support and Cables 1671-3

Group 1671
BATTERIES, SUPPORT AND CABLES
BATTERIES
GENERAL INFORMATION When replacing a battery, use the John Deere bat-
tery or its equivalent shown in the following chart:

(2 used)
Volts........................................ 12
John Deere Part Number. . . . . . . AT29160
(Standard Battery) I
BCIGroup..................................30H
Cold Cranking Amps (0°F) (-18°C) . . . 570
(-20°F) (-28°C) . _. 450
Reserve Capacity (minutes at 25 amps) . . . . 180

(2 used)
Volts........................................ 12
John Deere Part Number. . . . . .. . . AU42915
(Heavy Duty Battery) I
BCIGroup...................................4D
Cold Cranking Amps (0°F) (-18°C) . . 800
l--Seat Latch 4-Battery to Disconnect (-20°F) (-28°C) . 640
2-Battery to Starting Switch Cable
Reserve Capacity (minutes at 25 amps) . . ~. 310
Motor Cable 5-Batteries
3-Battery Connecting Cable
There are two important things that must be done
Fig. I-Battery Connections periodically in order to obtain long life from a battery.
(AU42915 Batteries Shown)
First, the electrolyte must at all times be kept
Two battery options are available on the JD750 above the plates and separators. The electrolyte lev-
Crawler. el should be checked once a week, or after fifty
hours of operation. See “Checking Electrolyte Level”
Batteries are located under the seat. To gain ac- in this group.
cess to the batteries, release seat latch (1, Fig. 1)
and lean seat forward. Second, be sure the battery is kept nearly charged
at all times. The state of charge should be checked
at frequent intervals by making specific gravity read-
ings with a battery hydrometer. See “Specific Gravity
Cell Comparison Test” in this group.

For additional information on batteries, refer

Fas to “Storage Batteries” in FOS Manual -
ELECTRICAL SYSTEM.
cl 0

Litho in U.S.A.
 16 Electrical Systems JD750 Crawler Bulldozer
16714 Batteries, Support and Cables TM- 1136 (Apr- 79)

Precautions Remove the AU42915 Batteries (with cab) as fol-

lows:
A CAUTION: All exposed metal surfaces on
batteries are “alive.” Never lay a metal ob-

q
1. Remove seat front support. I
ject on top of a battery as a short circuit may result.
’ ’ Sparks or an open flame must be kept away from
2. Note the location of the positive (+) terminals so
batteries due to the presence of explosive gas in
that the batteries are installed in the same way.
and around the batteries while they are being
charged or in use.
3. Disconnect the ground cable (battery-to-discon-
nect switch cable [4, Fig. 11) first. Use only a box end
A CAUTION: BATTERY ACID IS HARMFUL
ON CONTACT with the skin or materials. If
wrench to loosen clamps on terminals.
clamps, using a screw-type puller. DO NOT hammer
Remove

acid spills, here are some first aid tips to minimize

on the battery posts.
the damage:
4. Remove the connecting cable (3) and positive
1. Remove immediately any clothing on which acid
cable (battery-to-starting motor cable E21).
spills.
5. Tape or use plastic caps over the battery termi-
2. If acid contacts the skin, rinse the affected area
nals to prevent shorting terminals out during removal.
with running water for 10 to 15 minutes.
6. Remove battery tie down bolts.
3. If acid ever splashes into the eyes, force the lids
open and flood the eyes with running water for 10 td 15
7. On units with one-piece holddowns, position
minutes. Then see a doctor at once. Don’t use any
holddown on top of batteries and move it as far forward
medication or eye drops unless prescribed by the
and to the left as the rear terminal on rear battery will
doctor.
allow. Next, slide the front battery as far to the right as 1
possible and grab the left handle of the front battery.
4. To neutralize acid spilled on the floor, use one of
Lift the battery by the left handle through the holddown.
the following mixtures:
Once the front battery is free of the holddown, the rear
battery can be moved forward and the holddown re-
a. One pound (500 g) of baking soda in a gallon (4
moved.
L) of water.
On units with two-piece holddowns, remove the
b. One pint (400 mL) of household ammonia in a
holddowns and batteries as necessary. Remove front
gallon (4 L) of water.
holddown and battery for access to rear battery.

5. Acid from the batteries can also damage the

8. Check cables for worn or frayed insulation. Re-
paint and metal surface of the machine. Avoid over-
place cable clamps or bolts if corroded.
filling the battery cells and protect the battery when
necessary.
INSPECTION
REMOVAL Cleaning Batteries
1 The AT29160 Standard Batteries can be removed Wipe batteries with a damp cloth. If terminals are
by lifting them through the opening above the batteries corroded, use a stiff brush and wash with an ammonia
after wiring and hold downs have been removed. solution or a solution of baking soda (l/4 pound [l 10
g] added to a quart [l 11 of water). Keep vent plugs
I On units without cab, the AU42915 Heavy Duty tight while washing. After washing, flush battery and
Batteries can be removed by first removing one side compartment with clear water. Be sure vent holes in
seat support after the wiring has been removed. vent plugs are open.

Litho in U.S.A.
JD750 C&wler Bulldozer Electrical Systems 16
TM- 1136 (Apr- 79) Batteries, Support and Cables 1671-5

Checking Electrolyte Level

TEMPERATURE IN GRAVITY POINTS
Check electrolyte level in each cell. Proper level is to TO ADD OR
OF OF ELECTROLYTE 150
bottom of filler neck. Always add distilled water if SUBTRACT
FROM READING
available. If not, use clean soft water. Avoid hard water.
.
clljl
NEVER ADD ACID TO THE BATTERY unless
electrolyte is lost by spilling.

Always wait until after checking specific gravity be-

fore you add water to the battery. This will assure a true
reading. If level is too low to check specific gravity, add
water, operate engine for a few minutes to let water
and electrolyte mix, then check.

In freezing weather, never add water to the battery

unless it will be operated immediately to allow proper
mixing of water with electrolyte.
T31403N

TESTING Fig. 3-Electrolyte Temperature

Testing the battery will tell you whether the battery is Correction Table I
usable, requires recharging, or should be replaced.
Regular testing provides a means of anticipating bat- True readings are taken at 80°F (27°C) only. To
tery failure. correct a reading, add four gravity points (0.004) for
every 10°F (6°C) that the electrolyte temperature is
above 80°F (27°C). Subtract four gravity points (0.004)
If D-24001 MO Battery Tester is used, follow the
I
manufacturers instructions on the battery tester.
for every 10°F (6°C) that the electrolyte is below 80°F
(27°C). A hydrometer reading of 1.260 at 0°F (- 18°C)
is corrected to 1.228.
Specific Gravity Cell Comparison Test
Specific gravity should read from 1.215 to 1.270 .

0
(corrected for 80°F [27”Cl electrolyte temperature).

The variation in readings between cells should be no

more than 50 specific gravity points (0.050).
HOLD HYDROMETER
M--- VERTICALLY STRAIGHl If specific gravity readings show a difference be-
tween the highest and lowest cell of more than 50
specific gravity points (0.050) or more, the battery is
\TAKE READING
AT EYE LEVEL defective and must be replaced.
FLOAT MUST
BE FREE If the maximum difference between all readings is
less than 50 specific gravity points (0.050) and the
THERMOMETER lowest cell reading is 1.200 or above, the battery is in
good condition and may be returned to service.

T31402N

Fig. FChecking Specific Gravity

Check the specific gravity of each cell with an accu-

rate hydrometer equipped with a thermometer. Hold
the hydrometer vertically and take the reading at eye
level.

Litho in U.S.A.
16 Electrical Systems JD750 Crawler Bulldozer
1671-6 Batteries, Support and Cables TM- 1136 (A pr- 79)

If the maximum difference between all readings is Connect the high-rate discharge tester to the battery
less than 50 specific gravity points (0.050) but the and be sure to follow the manufacturer’s instructions
lowest cell reading is below 1.200, the battery is good (Fig. 4).
but needs to be charged by the slow method.
The terminal voltage reading should remain above
Specific Gravity 9.0 volts.
Reading (Adjusted) State of Charge

If the terminal voltage falls below 9.0 volts, the

1.260 100%
battery is defective or it is not as fully charged as the
1.230 75
specific gravity reading indicates in the specific gravity
1.200 50%
test.
1.170 25%
1.140 Minimal
To be sure of the battery condition, carefully charge
1.110 Completely Discharged
it and repeat the test.

The table above shows the state of charge of a

Remember these key facts when testing batteries.
typical battery at various specific gravity readings.
1. In general, if all cells of a battery test the same,
High-Rate Discharge Test
the battery is good. If all are low, the battery usually
To be sure of a battery’s ability to deliver current only needs recharging.
under load, give it a high-rate discharge test. This test
shows the internal conditions that might not otherwise 2. If there is a real difference between cells, the
be detected. battery generally must be replaced.

The following conditions must exist before this test is For additional information on “Battery Test-
made: ing” refer to “Storage Batteries” in FOS
Manual ELECTRICAL SYSTEMS.
1. Battery specific gravity must not be less than
1.215 at 80°F (27°C). Otherwise, erratic or unreliable
readings will result.

2. Battery electrolyte temperature must be between

70°F (21 “C) and 90°F (32°C).
il

P33000N
Fig. 4-High-Rate Discharge Battery
Tester Connected to Battery

Litho in U.S.A.
 JO750 Crawler Bulldozer Electrical Systems 16
TM-1136 (Nov-78) ’ Batteries, Supports and Cables 1671-7

CHARGING THE BATTERY If the battery has a specific gravity reading of

1 .150 or lower, disconnect battery cables and charge
Batteries can be recharged in two ways:
it until the specific gravity reading is 1 ,150 or above
before using a battery charger as a booster.
1. Fast charging.
2. Slow charging.
INSTALLATION
A battery that is in satisfactory condition but re- Install batteries as follows:
quires recharging will accept a large amo.unt of
charging current without undesirable effect. This type 1. Be sure the batteries are fully charged
of battery may be charged quickly at a high rate with
a battery fast charger. 2. Set batteries in tray making sure batteries are
resting level.
A battery that becomes sulfated, however, will not
accept a high rate of charging current without possi- 3. Tighten the battery clamp nuts evenly until bat-
ble damage. Its sulfated condition provides increased teries are secure. Do not overtighten as this will dis-
resistance to current flow within the battery. Flow of tort or crack the battery case.
a high rate of charging creates heat, which can result
-. in warping of the plates, boiling of electrolyte and 4. Clean the battery terminals and cable clamps
eventual damage to the separators. Cell caps and with a wire brush before attaching the clamps. This
covers and the battery case may be damaged or will assure a good contact.
distorted.
5. Check for correct polarity of the battery. Con-
A battery in this condition must be charged over a nect the positive cable first. Before connecting the
long period at a low rate. In this manner, sulfate for- ground cable, momentarily touch it against the bat-
mation on the plates will be gradually broken down tery post. With all switches and accessories off, no
and the battery returned to its normal charged state. spark should occur. If spark does occur, do not con-
nect the ground cable. Check for reversed battery
NOTE: When charging batteries be sure to follow polarity, improper alternator connection, defective
the manufacturer’s instructions for using the charger. electrical wire connection, or defective electrical
equipment.
For additional information on charging bat-
Fcs teries, refer to “Storage Batteries” in FOS 6. Tighten the clamps on the battery terminals.
Manual - ELECTRICAL SYSTEM. Use a box-end wrench carefully to avoid twisting the
0 a battery terminal posts.

John Deere battery chargers can be used as a 7. Coat the terminals with petroleum jelly to pre-
booster to start the engine. vent corrosion. Never paint the terminal parts.

IMPORTANT: Before hooking up the battery

charger to the batteries in the machine, review
the precautions in Section 90, Group 9015.

IMPORTANT: A battery charger should not be

used as a booster if a battery has a very low
charge (1.150 specific gravity reading or lower), A
low charged battery greatly increases the possi-
bility of connecting the charger to the battery in
reverse, and it is possible to reverse the charge
on a battery. If this is done the alternator diodes
or the wire harness may be damaged.

Litho in U.S.A.
16 Electrical Systems JD750 Crawler Bulldozer
1671-6 Batteries, Supports and Cables TM- 1136 (Nov-75)

Litho in U.S.A.
JD 7.50 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Nov-75) Alternator, Regulator and Charging System Wiring 1672-1

Group 1672
ALTERNATOR, REGULATOR AND
CHARGING SYSTEM WIRING .
a
The JD750 Crawler with cab has a 42 amp alter- It is not necessary to disassemble the alternator to
nator and regulator. The crawler without a cab has a replace brushes or voltage regulator. Such opera-
16 amp alternator and regulator. For information on tions are usually accomplished with the alternator left
the 16 amp alternator, go to page 16-1672-13. intact on the engine.

The alternator is cooled by an externally mounted

42 AMP ALTERNATOR fan. Correct air circulation requires air to be pulled
AND REGULATOR into the rear of the alternator and expelled through
the front housing.
GENERAL INFORMATION
The alternator can be divided into three main as-
semblies:
1. Rotor Assembly - magnetic field which rotates.

2. Stator Assembly - Conductors which are sta-

tionary.
3. Rectifier Assembly - diodes which change a.c.
current to d.c. current.
The rotor assembly consists of a wire coil wrapped
around an iron core and mounted on a rotating shaft.
The coil is enclosed between two interlocking soft
iron sections. The ends of the coil are connected to
two slip rings mounted on one end of the shaft.

Small brushes ride on the slip rings. One of the

brushes is connected to ground. The other is insulat-
ed and connects to the alternator field terminal. This
terminal is connected through the regulator and the
key switch to the batteries.
The rotor turns on sealed ball bearings that contain
lubrication for the life of the bearing.
The stator assembly is a laminated soft iron ring
with three groups of coils or windings in the slots.
Each group is made up of twelve coils.

One end of each stator winding is connected to a

positive and negative diode. The other ends of the
stator windings are wye connected.
l-Regulator 4-Output Terminal
To convert the a.c. current to d.c. current, diodes
2-Regulator Connector 5-Regulator Terminal
3-Ground Terminal
are used. Six diodes are mounted at the slip ring end
of the alternator housing. Three negative diodes are
Fig. I-Alternator and Regulator mounted in a heat sink bolted to the end frame.
Three positive diodes are mounted in the heat sink
The alternator assembly consists of an alternator which is insulated from the end frame.
and voltage regulator combined as a single unit as
shown in Fig. 1. It is an open type alternator with en-
closed brushes and slip rings.

Litho in U.S.A.
16 Electrical Systems JD750 Crawler Bulldozer
1672-2 Alternator, Regulator and Charging System Wiring TM-I 136 (Nov-75)

To understand the diodes, first remember these To remove the alternator, turn off battery discon-
two points: nect switch. Remove connector from top of regulator
and disconnect wire leads from alternator output ter-
1. Alternating current flow is produced by the ro- minal.
tor-stator combination. That is, during half the rotor
Loosen adjusting bracket cap screw and mounting
revolution, current flow in the stator phases is in one
bracket screw and nut. Push alternator toward en-
direction. In the other half, flow is in opposite direc-
gine and remove fan belt from alternator pulley. Re-
tion.
move adjusting strap cap screw and mounting
bracket cap screw, nut, spacer and washers. Re-
2. Current flow from the alternator output terminal
move alternator.
is always the same direction.
REPAIR
This means that during each phase of a revolution,
two diodes are used to convert a.c. to d.c. current - Refer to Fig. 4 during disassembly and assembly.
one positive and one negative diode.
Never immerse the alternator in cleaning solution.
Scrape off dirt and grease, then use a stiff brush and
For additional information on alternators, re- solvent. Dry with compressed air.
fer to “Charging Circuits” in FOS Manual -
ELECTRICAL SYSTEMS. Never hammer or jar the diodes as this may dam-
age them.

REMOVAL Disassembly
Remove regulator from rear housing. To remove
regulator, disconnect three wires from alternator
terminals, and remove four screws and carefully re-
move regulator connector from brush holder assem-
bly.

l-Regulator Wire 4-Mounting Bracket

Connector Screw
2-Adjusting Strap Screw 5-Output Terminal
3-Fan Belt

Fig. P-Alternator Wire Leads and Mounting Bracket

l-Brush Attaching 3-Brush Holder

Screws 4-Hex. Nuts
2-Through Bolts 5-Insulating Washers

Fig. 3-Brush Assembly

Litho in U.S.A.
.-
JD750 Crawler Bulldozer Electrical Systems 16
TM-1 136 (Nov-75) Alternator, Regulator and Charging System Wiring 1672-3

l-Special Cap Screw 9-Insulating Washer (4 used) 16-Special Cap Screw 24-Front Housing
(4 used) 19-Rear Bearing Retainer 17-Lock Washer 26-Span Spacer
2--Regulator 1 l--Rear Housing 18-Slip Ring Assembly 26-Lock Washer
a--Gasket 12-insulator Sleeve (2 used) 19-Rear Bearing 27-Machine Screw
U-Drive Screw (2 used) 13-Positive Rectifying Diode PO-Rotor 28-Woodruff Key
6-Brush Holder Negative Rectifying Diode 21-Sleeve 29-Fan
6-Through Bolt (4 used) 14-Stator 22-Retainer 39--Pulley
I-Nut (4 used) 16-Diode Trio 23-Front Bearing 31-Lock Washer
8-Lock Washer (4 used) 32-Nut

Fig. 4-Alternator Assembly

Remove brush holder (3, Fig. 3) and through bolts Removing Rear Housing from
(2) from alternator. Stator and Diodes
Place the open end of the stator on a clean work
Carefully insert two screwdriver blades in opposite surface, free of metal chips that could damage the
openings between the stator and front housing and stator windings. Remove hex. nuts (4, Fig. 3) and in-
separate front housing from rear housing.
sulating washers (5) from the diode terminal studs.

IMPORTANT: inserting screwdriver blades Carefully and evenly, tap the diode terminal studs
deeper than l/16” (1.6 mm) may damage stator out of the rear housing and lift rear housing off the
windings.
studs.

At this time, the rear housing and stator are one Inspect the rear housing for a cracked or broken
assembly; the front housing and rotor are another casting, stripped threads or evidence of severe wear
assembly. in the bearing bore due to a worn rear bearing.

Litho in U.S.A.
16 Electrical Systems JD 750 Crawler Bulldozer
1672-4 Alternator, Regulator and Charging System Wiring TM- 7 736 (Nov-75)

Fig. 6-Pulley Removal

l-Rear Housing a--Rear Bearing Retainer

Fig. 5-Rear Housing

If rear housing is to be reused, clean in solvent,

dry with compressed air, and install a new rear bear-
ing retainer (2, Fig. 5).

Removing Pulley and Woodruff Key

The pulley is a slip-fit on the rotor shaft, positioned
with a Woodruff Key. To remove the nut and lock
washer from the shaft, clamp the pulley in a vise us-
ing an over-sized belt to protect the pulley from the
vise jaws (Fig. 6).

Remove the nut and lock washer from the rotor

shaft and pull alternator from the pulley. A slight
rocking of the alternator body will loosen a tight pul-
ley.
l-Woodruff Key %-Pulley Nut
3-Screwdriver Blade

Fig. 7-Woodruff Key Removal

Remove fan and Woodruff Key (Fig. 7).

Inspect the fan for cracked or broken fins and note

condition of the mounting hole. If hole is worn from
running loose, replace the fan to insure balance.

Inspect pulley drive surfaces, key groove and bore

for wear.

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JD750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Nov- 75) Alternator, Regulator and Charging System Wiring 1672-5

Removing Front Bearing Retainer Removing and Installing Sleeve

and Front Housing
Figures 9, 10 and 11 show the procedure for re-
moval and installation of sleeve in front bearing.

1-A-216 Puller 2-A-203 Drive End

Bearing installation ’ ~
l-Front Bearing Retainer Screws Tool

Fig. d-front Housing Fig. B-Removing Front Bearing and Sleeve

Remove the three front bearing retainer screws (1,

Fig. 8) and lock washers.

Remove front housing from front bearing by tap-

ping rotor shaft against a wood block or using A-276
Puller.

Inspect front housing for a cracked or broken cast-

ing, stripped threads or evidence of severe wear in
the bearing bore due to a worn rear bearing.

If front housing ‘is to be reused, clean in solvent

and dry with compressed air.

Removing Front Bearing and Sleeve

from Rotor
1-A-209 Bearing and Pulley Removal and
Place A-203 Drive End Bearing Installation Tool
Installation Tool
over the end of the rotor shaft. Using A-216 Puller,
pull front bearing and sleeve from rotor (Fig. 9). Fig. lo-Pressing Sleeve Out of Front Bearing

Litho in U.S.A.
16 Electrical Systems JO750 Crawler Bulldozer
1672-6 Alternator, Regulator and Charging System Wiring TM- 1136 (Nov- 75)

Removing Slip Rings

Unsolder the rotor leads (1, Fig. 12) from the slip
ring terminals. Carefully unwind the ends of the rotor
leads from the slip ring terminals.

1-A-203 Drive End P-Front Bearing

Bearing Installation Tool 3-Sleeve

Fig. 1 l-Pressing Front Bearing on Sleeve

Position front bearing on two steel blocks as

shown in Fig. 10.

Using A-209 Bearing and Pulley Removal and In- l-Rotor Leads 2-Special Cap Screw
stallation Tool (1, Fig. lo), press sleeve out of front
bearing. Fig. 12-Slip Ring End View of Rotor

Position sleeve (3, Fig. 11) and front bearing (2) Remove special cap screw (2) from end of shaft
on press bed as shown in Fig. 11. and remove slip rings. If necessary, thread a l/4 x
l-1/2 UNF-2A cap screw into the slip ring hub; this
Using A-203 Drive End Bearing Installation Tool will back the slip ring assembly off the rotor shaft. Do
(1, Fig. 1 l), press front bearing (2) on sleeve (3) until not damage rotor leads or small fiber washers.
bearing bottoms.
Removing and Installing Rear Bearing .’
\
Installing Front Bearing Figures 13 and 14 show the procedure for removal
Using a brass drift and a hammer, install front and installation of rear bearing on rotor.
bearing with sleeve into front housing until bearing
bottoms. Secure with bearing retainer and attaching
screws.

Rotor
Check rotor for stripped threads on shaft, worn key
slot, worn bearing surface, scuffed pole fingers and
worn or dry rear bearing. Replace rotor if necessary.

Check condition of slip rings. If they need cleaning,

polish contact surfaces with No. 00 sandpaper or No.
400 grit silicone carbide paper.

If surfaces are worn beyond repair, replace the slip

ring assembly.
l-Rear Bearing 3-A-216 Puller
P-Rotor Leads

Fig. 73-Removing Rear Bearing

Litho in U.S.A.
JD750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Nov- 75) Alternator, Regulator and Charging System Wiring 1672-7

Using A-216 Puller, remove rear bearing from rotor ALTERNATOR COMPONENT TESTS
shaft. Be careful not to damage rotor leads.
Brushes
First make a visual check of the brushes. If the
brushes are worn down to an exposed length of l/4
in. (6.4 mm) or less, or are cracked or oil soaked, re-
i
place the entire brush assembly.

1-A-209 Bearing and Pulley 2-Rear Bearing

Removal and installation 3-A-201 Press Assembly
Tool

Fig. 74-installing Rear Bearing

Support the pulley end of the shaft on the bed of A-Field Terminal C-Insulated Brush (Top)
the A-201 Press Assembly (3, Fig. 14). Place the B-Bracket D-Grounded Brush (Bottom)
new bearing over the end of the shaft. Position rotor
Fig. 15-Brush Test Points
leads away from the bearing. Using A-209 Bearing
and Pulley Removal and Installation Tool (l), press
Perform an insulation test on the brushes as fol-
bearing on the shaft until inner race contacts the
lows:
shoulder of the rotor.
1. Connect an ohmmeter or a 24-volt test lamp to
Installing Slip Rings field terminal (A) and bracket (B).
Guide rotor winding leads through the square pas-
sage in the slip ring hub (Fig. 12). Hand press the 2. Resistance should be high (infinite) or test lamp
slip rings on the shaft while maintaining alignment of should not light. If resistance is low or test lamp
winding leads and passage. Install special cap screw lights, brush assembly is shorted and must be re-
and lock washer (2, Fig. 12) and tighten to 35 lb-in placed.
(4 Nm) (0.4 kg-m).
Perform a continuity test on the brushes as fol-
Wrap leads (1, Fig. 12) around slip ring terminals lows:
(leads are interchangeable) and solder with rosin
core solder. DO NOT OVERHEAT. Apply silicone 1. Connect ohmmeter or test lamp to field terminal
rubber or a glue to secure wires to the end of the (A) and brush (C). Use an alligator clip to assure
rotor. good contact to brush.

Retest rotor as instructed under “Rotor Testing” to IMPORTANT: Be careful not to chip brush.
insure that a short circuit or ground did not develop
during repair operation. 2. Resistance reading should be zero or test lamp
should light. Move brush or brush lead wire to make
certain that the brush lead wire connections are se-
cure. The resistance reading should not vary when
brush and lead wire are moved.

Litho in U.S.A.
-
16 Electrical Systems JD750 Crawler Bulldozer
1672-8 Alternator, Regulator and Charging System Wiring TM- 1136 (Nov-75)

3. Connect ohmmeter to bracket (B) and grounded If the test lamp lights in both directions, the diode
brush (D). Resistance reading should be zero or test is shorted. If the test lamp does not light in either di-
lamp should light. Move brush and lead wire to make rection, the diode is open.
certain that the brush lead wire connections are se-
cure. Resistance reading should not vary when brush Test the remaining diodes of the assembly in the
and lead wire are moved. same manner. Replace the assembly if one or more
of the diodes is found to be faulty.
Diode Trio
Use the following procedure when using a 1.5 volt
ohmmeter test:

1. Connect one ohmmeter lead to the diode termi-

nal (1, Figure 16) and the other lead to the mounting
stud (2).

2. Note the ohmmeter reading.

3. Now reverse the ohmmeter leads and note the

reading.
l-Diode Terminals 2-Mounting Stud
4. A good diode will give a high reading in one di-
Fig. 76-Diode Trio Tesf Points
rection and a lower reading in the other direction.

If a diode tester is used, follow tester manufactur-

If the high and low readings between the three
ers testing instructions. If a commercial tester is not
diodes are reasonably close, the diodes are good. A
available, use a DC test lamp.
defective diode will have a reading obviously different
from the good diodes.
IMPORTANT: DO NOT USE A 1 lo-VOLT TEST
LAMP. USE A 12-VOLT DC TEST LAMP ONLY,
When soldering to a diode terminal, use solder
OTHERWISE DIODES WILL BE DAMAGED.
containing 60 percent tin and 40 percent lead, and
take care that a good connection is achieved without
If using a 12-volt DC test lamp, lamp should light
overheating the diode. Do not use acid core solder.
only when the diode is connected in a forward bias
as given below.
If the above tests indicate one or more faulty
diodes, the assembly should be replaced.
Connect one lead of the test lamp to one of the
diode terminals (1, Figure 16) and the other lead to
Stator
the mounting stud (2). Reverse the test lamp probes.
-ihe test lamp should light in one direction but not in Examine stator for insulation failure or defects.
the other. Shorted stator windings are usually discolored and
smell of burned insulation.

If a sensitive ohmmeter is available, use the fol-

lowing procedure:

1. Disconnect the stator leads from the diode as-

semblies.

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JD750 Crawler Bulldozer Electrical Systems 16
TM-l 136 (Nov-75) Alternator, Regulator and Charging System Wiring 1672-9

2. Check for a grounded winding by connecting an Rectifier Diode Test :i

ohmmeter to one stator lead and to the stator frame.
A humming or growling sound with considerably
The ohmmeter reading should be infinite (high).
low output (6 to 10 amps) is usually caused by a
shorted diode. If output is slightly below maximum, a
3. To check for an open-circuited or short-circuited
diode may be open-circuited.
winding, carefully zero the ohmmeter and connect
the ohmmeter leads to A and B (Fig. 17). The meter
If available, use a diode tester and follow the man-
reading should be approximately 0.6 ohm. An infinite
ufacturer’s instructions. Do not use a 1 lo-volt test
or high reading indicates an open-circuited winding.
lamp to check a diode.
Now touch the remaining A and B leads together
several times. The meter pointer should deflect
If using a 12- or 24-volt test lamp, use the follow-
slightly to zero. If there is no pointer movement, the
ing procedure:
windings are shorted.

T38427N

l-Diode Plate 2-Diode Terminals

fig. 7847ectifier Diode Test Points

1. Connect test lamp probes to diode terminal and

to diode plate (See Fig. 18), then reverse test lamp
probes.
fig. 77-Stator Leads
2. The test lamp should light in one direction but
4. Check for an open circuit or a shoft circuit be- not in the other.
tween A and C and between B and C in the same
manner. 3. If the test lamp lights in both directions, the
diode is shorted.
If a sensitive ohmmeter is not available for the
above procedures, carefully disconnect the stator 4. If the test lamp does not light in either direction,
leads AA, BB and CC from each other (stator leads the diode is open.
may be brittle if they have been overheated or if they
are old). 5. Test the remaining diodes of the assembly in
the same manner. Replace entire assembly, if one of
Test the stator as instructed in FOS Manual the diodes is found to be defective.
FQS 20 - ELECTRICAL SYSTEMS.

cl 0

Litho in U.S.A.
16 Electrical Systems JD750 Crawler Bulldozer
1672-l 0 Alternator, Regulator and Charging System Wiring TM- 1136 (Nov- 75)

If using a 1-l/2-volt ohmmeter use the following Test 1: Continuity and Current Draw
procedure:
This test checks the rotor for shorted or open
windings.
1. Connect one ohmmeter lead to the diode plate
(1, Fig. 18) and the other lead to the diode terminal.
Connect the voltmeter to the slip rings (be sure slip
rings are clean). Then connect an ammeter in series
2. Note the ohmmeter reading.
with a variable resistor to the slip ring and a 12-volt
power source. Set the variable resistor to maximum
3. Reverse the ohmmeter leads and note the
resistance. Connect the other slip ring to the power
reading.
source and adjust the resistor to obtain full battery
voltage (Fig. 19).
4. A good diode will give a high and a low read-
ing.
IMPORTANT: Do not remove the rotor leads
from the slip rings at this time, as it will cause an
5. If a high and low readings between the three
arc, damaging the slip ring surface and requiring
diodes are identical, the diodes are good. A slightly
clean-up.
different reading indicates a defective diode.
Rotor current draw at 70°F to 80°F (21°C to 27°C)
When soldering a diode lead, use a pair of pliers
should be 0.50 to 1 .I0 amps at 1O-volts.
as a heat sink between the diode and soldering iron.
Use solder containing 60 percent tin and 40 percent
Resistance of windings should be 13.4 to 14.6
lead. Never use an acid-core solder.
ohms at 70°F to 80°F (21°C to 27°C).

If a diode is defective, replace the diode assembly.

Shorted windings are indicated by excessive cur-
Note the insulator locations on the positive diode as-
rent draw, and open windings by no current draw at
sembly to aid in correct assembly. The diode con-
all.
nections and polarity must be correct. A positive
diode assembly as a l/4 x 20 terminal stud and a
Test 2: Checking Field Coil for Leakage or Shorts
square hole. A negative diode assembly has two, 10
x 32, terminal studs. h

Rotor Tests

l’38428N

l-Slip Rings P-Rotor Shaft

fig. PO-Test 2 Test Points

l-Voltmeter 4-Variable Resistor

2-Rotor Assembly 5-Battery
3-Ammeter

Fig. 19-Rotor Current Draw Test Hook-Up

Litho in U.S.A.
JD750 Crawler Bulldozer Electrical Systems 16
TM-I 136 (Nov-75) Alternator, Regulator and Charging System Wiring 1672-l 1

This test checks the field coil for leakage or shorts Assembling Rectifier Diode to
to the rotor poles. An ohmmeter or test lamp may be Rear Housing
used for the test.

Connect ohmmeter or test lamp probe to the slip

rings (1, Fig. 20) and to rotor shaft (2). Ohmmeter re-
sistance should be high (infinite) or test lamp should
not light. If resistance is not high (infinite) or test
lamps lights, leakage or a short exists between field
coil and rotor.

If rotor assembly fails either of the above tests, it

must be replaced.

ASSEMBLY

Assembling Front Housing on the Rotor

Position two blocks under rotor. Blocks should be
high enough so slip rings do not touch table. Be
careful not to damage field wire. Place front housing
over shaft. Press on inner race only by using A-209
Bearing and Pulley Removal and Installation Tool.
Press until inner bearing race contacts shoulder on
the shaft.
l-Insulating Washer 3-Slip Ring
P--Brush Assembly
Place spacer over shaft. Install Woodruff Key and
fan. Install pulley, lock washer and nut. Tighten nut Fig. PI-Rectifier Diode to Rear Housing
to 40 to 50 lb-ft (54 to 68 Nm) (6 to 7 kg-m).
Carefully insert rectifier diode terminal studs and
Spin rotor by hand to test freedom of bearing. diode trio stud through the rear housing. Install insu-
lating washer (1, Fig. 21) and hex. nuts. Tighten nuts
to 33 to 40 lb-in (4 to 5 Nm) (0.4 to 0.5 kg-m). Do
not tighten output stud.

Assembling Front Housing to

Rear Housing
Lubricate the exposed area of the rear bearing re-
tainer with hydraulic brake fluid to ease assembly
over the rear bearing. DO NOT USE OIL.

Place rear housing over the slip ring end of the ro-
tor and hand press housings together. Install through
bolts and tighten brush mounting screws to 30 to 35
lb-in (3 to 4 Nm) (0.4 kg-m).

Be careful not to damage slip ring.

Spin rotor by hand to test freedom of bearings.

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16 Electrical Systems JD750 Crawler Bulldozer
1672-12 Alternator, Regulator and Charging System Wiring TM-l 136 (Nov-75)

Installing Brush Assembly TEST AFTER ASSEMBLY

Place the brush assembly in the cavity and tiqhten
brush mounting screws to i6 to 20 lb-in (2 Nmj (0.2
kg-m).

Installing Regulator

l-Brush Terminal 3-24-Volt Power Source

P-Carbon Pile 4-Ammeter
Resistor 5-Voltmeter
6-Jumper Wire

Fig. 23-Alternator Test Connections

Mount alternator on electrical services and follow

service instructions. If instructions are not available,
connect altenator as shown in Fig. 23. Run alternator
at 3000 to 4000 rpm. Momentarily connect a jumper
wire between alternator output terminal and regulator
terminal to excite alternator field. Adjust resistor to
obtain maximum output.

Open resistor and check regulator operation. If

battery is partially discharged, it may be necessary to
connect a l/4 ohm resistor in series with the amme-
ter.
l--Regulator Terminal O-Orange
2-Output Terminal R-Red
3-Insulating Washer B-Black INSTALLATION
4-Ground Terminal
Mount alternator on mounting bracket with screw,
Fig. 22-Regulator Connections nut, spacer and washers; do not tighten screw. Install
adjusting strap screw through strap; do not tighten
Place gasket between regulator and rear housing. screw. Place fan belt on alternator pulley.
Connect regulator brush lead to brush terminal. In-
sert regulator mounting screws. DO NOT tighten. Adjust fan belt tension according to instructions in
Section 90, Group 9010 and tighten mounting and
Place regulator leads on regulator terminal and adjusting screws.
ground terminal and under output terminal nut.
Connect wires to regulator and alternator output
Install lock washers and nut for ground and regula- terminal. Turn on battery disconnect switch.
tor terminal. Tighten nuts to 35 to 45 lb-in (4 to 5
Nm) (0.4 to 0.5 kg-m). Tighten nuts at output termi-
nal to 3.5 to 40 lb-in (4 to 5 Nm) (0.4 to 0.5 kg-m).
Tighten regulator mounting screws to 30 to 35 lb-in
(3 to 5 Nm) (0.4 kg-m).

Litho in U.S.A.
JD750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Nov-75) Alternator, Regulator and Charging System Wiring 1672-l 3

16 AMP ALTERNATOR AND The alternator can be divided into three main as-
semblies:
REGULATOR
GENERAL INFORMATION 1. Rotor Assembly

2. Stator Assembly
- magnetic field which rotates.

- conductors which are sta-

.
q
tionary.

3. Rectifier Assembly - diodes which change a.c.

current to d.c. current.

The rotor assembly consists of a wire coil wrapped

around an iron core and mounted on a rotating shaft.
The coil is enclosed between two interlocking soft
iron sections. The ends of the coil are connected to
two slip rings mounted on one end of the shaft.
Small brushes ride on the slip rings.

The rotor turns on sealed ball bearings that contain

lubrication for the life of the bearing.

The stator assembly is a laminated soft iron ring

with three groups of coils or windings in the slots.
Each group is made up of from e’ght to sixteen coils,
depending on the design.
I
One end of each stator winding is connected to a
positive and negative diode. The other ends of the
stator windings are wye connected.
l--Regulator Wire Connector 4-Negative Diodes
2-Voltage Regulator E&Output Terminal To convert a.c. to d.c. current, diodes are used.
3-Ground Terminal 6-Regulator Terminal
Six diodes are mounted at the slip ring end of the al-
7-Capacitor
ternator housing. Three negative diodes are mounted
Fig. 24Alternator in the rear housing. Three positive diodes are mount-
ed in the heat sink which is insulated from the rear
The alternator is of a totally enclosed type with at- housing.
tached voltage regulator, designed for dusty or haz-
ardous environments. The alternator is not
waterproof and should not be submerged.

The alternator does not have to be disassembled

to replace voltage regulator or brush assembly. Such
operations are usually performed with the alternator
left on the engine.

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 16 Electrical Systems JD750 Crawler Bulldozer
1672-l 4 Alternator, Regulator and Charging System Wiring TM-1 136 (Nov-75)

To understand the diodes, first remember these The voltage regulator controls the voltage the al-
two points: ternator produces.

q
1. Alternating current flow is produced by the ro- A capacitor is connected between the alternator
. tor-stator combination. That is, during half the rotor output terminal and ground to protect the alternator
revolution, current flow is one direction. In the other diodes from voltage spikes.
half, flow is in the opposite direction.
For additional information on alternators or
2. Current flow from the alternator
is always the same direction.
output terminal

This means that during each phase of a revolution

two diodes are used to convert ac. to d.c. current -
clFos

o
voltage regulators, refer to “Charging Cir-
cuits” in FOS Manual - ELECTRICAL SYS-
TEMS.

one positive and one negative diode.

REMOVAL

A CAUTION: Turn battery disconnect lever

to “OFF” position to prevent damage if
leads removed from alternator should be acci-
dentally grounded.

Remove wire from output terminal (2, Fig. 25) and

disconnect wire connector from top of voltage regula-
tor.

Remove adjusting cap screw (3). Remove cap

screw and nut holding alternator to mounting bracket
(1).

l-Mounting Bracket 3-Adjusting Strap Remove alternator.

Bolt Screw
2-Output Terminal 4-Regulator Wire
Connector

Fig. 25-Alternator Wire Leads and Mounting Bracket

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JD 750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Nov-78) Alternator, Regulator and Charging System Wiring 1672-15

REPAIR
Refer to Fig. 26 or 27 during disassembly and as- Disassembly
sembly.
Remove regulator. Disconnect wire lead from each
terminal on alternator. Tag wires for assembly. Re-
Never immerse the alternator in cleaning solution.
move three screws holding regulator to alternator.
Scrape off dirt and grease; then use a stiff brush and
Pull regulator away and disconnect lead wire from
solvent. Dry with compressed air.
field terminal.

Never hammer or jar. the alternator, as this may

damage the diodes.

l-Drive Screw (2 used) ‘.’ 17-Lock Washer 33-Special Bolt (3 used)

2-Brush Cover 19-Lock _Washer (5 .used) 34-Negative Diode (3 used)
3-Brush Cover Gasket 19-Woodruff Key 3!i-Insulator (3 used)
4-Brush Insulator 20-Spacer 36Rear Bearing Retainer
S-Brush and Holder Pl-Machine Screw (3 used) 37-Rear Housing
S-Jumper Cable 22-Lock Washer (3 used) 3&Insulator Sleeve
7-Positive Diodes (3 used) “. 23-Front Housing 39-Insulator Washer
8-Diode Trio 24-Special Washer 40-Capacitor
B-Insulator (5 used) 2%Slinger Spacer 41-Nut (2 used)
lO-Bolt (2 used) 2S-Gasket 42-Through Bolt (4 used)
1 l-Stator 27-Front Bearing 43-Insulator
12-Bolt l&Shatt Sleeve 44-Insulating Washer (2 used)
13-Insulator Washer (3 used) 29-Front Bearing Retainer
14-Nut (10 used) 30-Rotor
1 S-Lock Washer 31-Rear Bearing
16-Pulley Nut 32-Positive Diode Plate

Fig. 26- 16 Amp Alternator( -279535)

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16 Electrical Systems JD750 Crawler Bulldozer
1672-16 Alternator, Regulator and Charging System Wiring TM-1 136 (Nov-78)

IO

T56417fi

l---Drive Screw (2 used) %-Special Bolt (3 used) 3&Rear Bearing

2-Brush Cover 17-Insulator (3 used) 31-Vee Ring
3-Brush Cover Gasket l&Rear Searing Retainer Seal (2 used)
4-Brush Insulator 19-Rear Rousing 32-Rotor
%-Brush and Holder 2~Negative Rectifying 33-Front Bearing
6-Jumper Cable Diode (3 used) Retainer
7-Insulator (5 used) 21-Capacitor M-Front Bearing
B-Bolt (2 used) 22-insulator 3!5-Double Lip Seal
9-stator 23-Drain Clip 36-Front Rousing Gasket
lo-Nut (10 used) 24-Through Bolt (4 used) 37-Front Rousing
11-Lock Washer (5 used) 2eut (2 used) 36-Lack Washer (3 used)
12-insulator Washer (3 used) 26-Washer 3g-Cap Screw (3 used)
13-Dutput Terminal Stud 27-insulator Washer 4Ct-Pulley Spacer
M-Positive Rectifying (2 u=m 41-Woodruff Key
Diode (3 used) 23-insulator Washer 42-Pulley
1 S-Positive Diode Plate 29-Insulator Sleeve 43-Lock Washer
44-Pulley Nut
45-Diode Trio

F$ 27-16 Amp Akrnator Assembly (279536- I

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JD750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Nov-78) Alternator, Regulator and Charging System Wiring 1672-17

Brushes
NOTE: It is nof necessary to remove the alternator
from the unit to check the brushes.

Carefully pry brush cover from alternator housing.

Remove two screws holding brush assembly and

carefully remove assembly and insulator.

Fig. 29-Separating Front and Rear Housings

Stator

Fig. 28-Removing Brush Assembly

Measure length of brushes beyond holder. Brushes

should be replaced if they measure less than l/4 inch
(6.35 mm).

IMPORTANT: If brush cover gasket or insulator

should become torn or damaged during brush re-
moval, gasket or insulator must be replaced and
properly positioned.

Rear Housing
Remove the four through bolts retaining the front
and rear housings. Using two screwdrivers (Fig. 29),
apply equal pressure to release the rear housing from
the front. Care should be taken that the stator stays
with the rear housing.

IMPORTANT: If housing gasket is damaged, re- Fig. 30-Removing Stator from Rear Housing
place it at time of assembly.
Grasping the stator, apply pressure and separate
stator from housing (Fig. 30).

Remove the stator wires from the terminals in the

rear housing. Note wire connections for assembly.

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 16 Electrical Systems JD750 Crawler Bulldozer
1672-18 Alternator, Regulator and Charging System Wiring TM-1 136 (Nov-78)

Diodes Using a small punch and A-206 Tool (1, Fig. 32), I
press defective positive diodes out of heat sink.
Remove diode trio wires and positive and negative
diode wires. Note wire connections for assembly. Re-
move rear housing nut from diode trio and remove
diode trio. Remove remaining wires from heat sink.

1-A-213 Tool 2-Housing

Fig. 33-Removing Defective Negative Diodes

Using A-213 Tool (1, Fig. 33), press defective neg-

ative diodes out of the rear housing.

IMPORTANT: The rectifying diodes used in this

application have welded rather than soldered
leads. Do not attempt to use replacement diodes
I Fig. 31 -Removing Diode Heat Sink with soldered leads.

Remove remaining nuts from rear housing retaining

the heat sink and remove heat sink.
NOTE: Three mica insulators are sef against the
inside of the rear housing and insulate the positive heat
sink from the housing.

1-A-214 Tool 2-Diodes

Fig. 34-Installing Positive Diodes

1-A-206 Tool 2-Diode

I Fig. 3N?emoving Defective Positive Diodes

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 JD750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Nov-78) Alternator, Regulator and Charging System Wiring 1672-19

1-A-214 Tool 2-Diode

Fig. 37-Pressing Rotor Out of Housing

I Fig. 354nstalling Negative Diodes

Using a press (Fig. 37), press rotor out of front
housing.
Place a new diode in diode hole. Rotate diode so
serrations on new diode do not line up with the sera-
tions made by original diode; this provides a more Bearings are sealed and cannot be lubricated. Re-
efficient transfer of heat from the diode. Press diode move the bearings using A-216 Puller and Adapter
1 fully into hole using A-214 Tool (Figs 34 and 35). (Fig. 38).

Check slip rings (4, Fig. 38) for contamination. If

Rotor
contaminated, clean with non-petroleum base cleaning
Remove the three screws and lock washers from the solvent. If solvent does not clean the slip rings, use
1 front housing (Fig. 36). If not already removed, remove crocus cloth.
Woodruff key from rotor shaft.

1-A-216 Puller and 3-Rear Searing

Adapter Tool 4-Slip Rings
2-Front Bearing

F@. 38-Removing Rotor B-sarings I

Fig. 36-Removing Rotor Retaining Hardware

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 16 Electrical Systems JD750 Crawler Bulldozer
1672-20 Alternator, Regulator and Charging System Wiring TM-1 136 (Nov-78)

ALTERNATOR COMPONENT TESTS

Make the following tests to locate faulty compo- Rectifier Diode Test
nents prior to assembly.
If a commercial alternator rectifier diode tester is
available, follow manufacturers instructions to test all
diodes. Do not use -120-volt AC test lamp.
First make a visual check of the brushes. If the
brushes are worn down to an exposed length of l/4 A 12 or 24-volt battery-operated test lamp or ohm-
in. (6.4 mm) or less, or are cracked or oil soaked, re- meter may be used if a commercial tester is not avail-
place the entire brush assembly. able. Connect one test lead to diode heat sink (2, Fig.
40), and the other to each diode wire terminal (1). Then I
repeat test with test leads reversed. Lamp should light
with leads in one position, but should not light with test
leads reversed. All diodes in heat sink or rear housing
should show the same results.

A-Field Terminal C-Insulated Brush (Top)

B-Bracket D-Grounded Brush (Bottom)

I Fig. 39&u& Test Points

Perform an insulation test on the brushes as fol-

l-Terminal Screws 2-Heat Sink
lows:
Fig. 40-Rectifier Diode Test Points I
1. Connect an ohmmeter or a 12- or 24-volt test
lamp to field terminal (A) and bracket (B). If lamp lights, regardless of how test leads are
2. Resistance should be high (infinite) or test lamp switched, the diode is shorted. If lamp fails to light in
should not light. If resistance is low or test lamp either test, the diode is open. Replace defective
lights, brush assembly is shorted and must be re- diodes. Observe correct polarity by color of lead wire.
placed. Negative diode has a black lead wire and positive
diode has a red lead wire.
Perform a continuity test on the brushes as fol-
lows:

1. Connect ohmmeter or test lamp to field terminal

(A) and brush (C). Use an alligator clip to assure
good contact to brush.

IMPORTANT: Be careful not to chip brush.

2. Resistance reading should be zero or test lamp

should light. Move brush or brush lead wire to make
certain that the brush lead wire connections are se-
cure. The resistance reading should not vary when
brush and lead wire are moved.

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 JD750 Crawler Bulldozer Electrical Systems 16
TM-l 136 (Nov-78) Alternator, Regulator and Charging System Wiring 1672-21

Diode Trio If the test lamp lights in both directions, the diode is
shorted. If the test lamp does not light in either direc-
tion, the diode is open.

Test the remaining diodes of the assembly in the

same manner. Replace the assembly if one or more of
the diodes is found to be faulty.

Use the following procedure when using a 1.5 volt

ohmmeter test:

1. Connect one ohmmeter lead to the diode termi-

l-Diode Terminals 2-Mounting Stud nal (1, Figure 41) and the other lead to the mounting 1
stud (2).
I Fig. 4 l-Diode Trio Test Points

2. Note the ohmmeter reading.

If a diode tester is used, follow tester manufacturers
testing instructions. If a commercial tester is not avail-
3. Now reverse the ohmmeter leads and note the
able, use a DC test lamp.
reading.

IMPORTANT: DO NOT USE A 11 O-VOLT TEST

4. A good diode will give a high reading in one
LAMP. USE A 12- OR 24-VOLT DC TEST LAMP
direction and a lower reading in the other direction.
ONLY, OTHERWISE DIODES WILL BE DAMAGED.
If the high and low readings between the three
If using a 12 or 24-volt DC test lamp, lamp should
diodes are reasonably close, the diodes are good. A
light only when the diode is connected in a forward bias
defective diode will have a reading obviously different
as given below.
from the good diodes.

Connect one lead of the test lamp to one of the diode

1 terminals (1, Figure 41) and the other lead to the
mounting stud (2). Reverse the test lamp probes. The
test lamp should light in one direction but not in the
other.

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 16 Electrical Systems JD750 Crawler Bulldozer
1672-22 Alternator, Regulator and Charging System Wiring TM-1 136 (Nov-78)

Stator Tests

T34581N

l-Winding 3 -Case l-Voltmeter 4-Variable Resistor

2-Common A-B-C-Stator Leads 2-Rotor Assembly !&Battery
3-Ammeter
I Fig. 4%Slator Test Points
Fig. 43-Rotor Current Draw Tesf Hook-Up
An ohmmeter or test lamp may be used to test for
opens. Rotor field current draw should equal 0.50 to 1 .lO
,ampere at 10.0 volts (70°F to 80°F 121“ to 27”C’j).
1. Connect ohmmeter or test lamp probe to one of
the stator leads (A, B, or C) and connect the other Shorted windings are indicated by excessive cur-
test probe to each remaining lead. rent draw, open windings by no current draw at all.

Resistance reading should be approximately zero Test B - Checking Field Coil for
or test lamp should light. If resistance reading is not Leakage or Shorts
zero or test lamp does not light, there is an open in
the stator windings. Replace stator. This test checks the field coil for leakage or shorts
to rotor poles. An ohmmeter or test lamp (12-volt)
2. To test for shorts, connect one ohmmeter or may be used.
test lamp probe to the stator windings and the other
test probe to the stator case. Resistance reading
should be infinite or test lamp should not light. If test
lamp lights or there is a resistance reading, a short
exists in the stator. Replace stator.

Rotor Tests
Test A: Continuity and Current Draw 134582N

Thi< test check? the rotor for shorted or open

windings. Connect voltmeter to the slip rings. Then
connect an ammeter in series with a variable resistor Fig. 44-Tesl 6 Tesf Points

to the slip ring and 12-volt battery. Set the variable

Connect ohmmeter or test lamp probes to one of
resistor to maximum resistance. Connect the other
the slip rings, and to rotor shaft. Ohmmeter resis-
slip ring to the battery and adjust the resistor to ob-
tance should be infinite and test lamp should not
tain full battery voltage.
light. If resistance is not infinite or test lamp lights,
IMPORTANT: Do not remove the wire from the leakage or a short exists between the field coil and
slip ring at this time as it will cause an arc, dam- rotor.
aging the slip ring surface and requiring cleanup.

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JD750 Crawler Bulldozer Electrical Sys terns 16
TM- 1136 (Nov-78) Alternator, Regulator and Charging System Wiring 1672-23

ASSEMBLY
Bearings
Installing Front Bearing (

T58362N

1 -Rear Bearings !5-Front Searing

2-V-Ring Seal (2 used) 6-Double Lip Seal
l-A-201 Tool 2-A-203 Tool 7-Lock Washer (3 used)
3-Rotor Assembly
4-Front Bearing Retainer &Cap Screws (3 used)
Fig. 45lnstalling Bearing in Front Housing
Fig. 46-Bearing and Sea/ Placement I
Check that bearing cavity in front housing is clean
and that felt dust seal is installed in recess. Press Coat bearing retainer forward side with John Deere
bearing into housing using A-203 Tool (1, Fig. 45). Low Strength Loctite or equivalent.
Apply even pressure only to the outside race of the
bearing. Install bearing retainer and secure with Install bearing retainer and secure with cap screws
screws and lock washers. and lock washers.

Installing Front Bearing and Coat V-Ring Seals (2, Fig. 46) with high temperature I
Seals (279536- ) silicon base grease.
Wipe off old grease. Apply new grease to areas as
Install V-Ring seal with rubber lip toward front bear-
directed below.
ing.
Apply high temperature silicone base grease
Install V-Ring seal on rotor shaft with rubber lip
(AT30408 or equivalent), to double lip seal (6, Fig. 46).
towards rear bearing.
Insert double lip seal in front housing.

Install front bearing. Press bearing into front hous-

ing. Apply an even pressure to the outside race of the
bearing.

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 16 Electrical Systems JD750 Crawler Bulldozer
1672-24 Alternator, Regulator and Charging System Wiring TM- 1136 (Nov-78)

Installing Rotor Installing Diode Heat Sink

Coat the three mica insulators with a thin coat of

a.
silicon grease or petroleum. Make certain that all in-
sulating washers are properly positioned. Secure heat
sink to housing with terminal bolts.

Attach diode leads and stator leads to heat sink.

Assembling Stator To Rear Housing

Check that rear bearing retainer is properly seated in

rear housing. Place stator in rear housing, with leads
extended toward heat sink. Assemble leads to ,diode
terminal screws. Each screw should hold a black neg-
ative diode lead, a red positive diode lead, a lead from
the diode trio, and a lead from the stator. The terminal
screw nearest the stator terminal will also hold the
stator top lead wire.

Arrange all leads to prevent accidental contact with

surfaces, through bolts, or the rotor. Align stator slots
1-A-209 Tool 3-A-208 Tool with through bolt holes.
2-A-205 Tool

Fig. 47-Installing Rotor

Assembling Front and Rear Housing

I
Place front housing with rotor assembly in a vise,
Press assembled front housing onto rotor assembly with the drive end down. Place sealing gasket over top
using A-209 Tool (1, Fig. 47). Support end of rotor edge of front housing. Place rear housing and heat sink
shaft with A-205 Tool inside of A-208 Tool as illustrat- assembly over top end of rotor, align bearing cavity,
ed. and press housings together.

Installing Rear Bearing Position gasket to align with through bolts and tight-
en securely. Spin rotor by hand to check that diode
Support front housing in press using A-208 Tool.
wires are not rubbing against rotor.
Using A-206 Bearing Driver, press bearing on rotor
shaft up to shoulder.

Install new rear bearing retainer in rear housing.

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JD750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Nov-78) Alternator, Regulator and Charging System Wiring 1672-25

TEST AFTER ASSEMBLY

T384311

l-Brush Terminal 3-24-Volt Power Source

2-C8rbon Pile 4-Ammeter
Resistor 5-Voltmeter
6-Jumper Wire

Fig. 49-Alternator Test Connections

l-Rear Housing 2-Drain Clip

Mount alternator on electrical services and follow
Fig. 46-Installing Drain Clip (279636- )
service instructions. If instructions are not available,
connect alternator as shown in Figure 49. Run alter- 1
Attach drain clip to rear housing with through bolt. nator at 3000 to 4000 rpm. Momentarily connect a
Tighten securely. jumper wire between alternator output terminal and
regulator terminal to excite alternator field. Adjust re-
Installing Brush Assembly sistor to obtain maximum output.

Place insulator over brush assembly. Slide assem- Open resistor and check regulator operation. If bat-
bly into brush cavity and position with alignment pins. tery is partially discharged, it may be necessary to
Secure insulator and brush assembly to rear housing connect a l/4 ohm resistor in series with the ammeter.
and tighten screws.
INSTALLATION
Position brush cover gasket on alternator and install
the brush cover and connect lead. Install alternator. Connect alternator wires making
sure all connections are clean and tight. Turn battery
Installing Regulator disconnect switch on.

Connect the regulator green wire to the brush cover Check belt tension. See Section 90, Group 9010.
and install regulator. See Fig. 24 for connecting stator
and ground wires.

Installing Pulley
Place pulley spacer over rotor shaft and install
Woodruff key in slot. Place pulley on shaft and tighten
nut to 40 to 50 lb-ft (54 to 68 Nm) (6 to 7 kg-m).

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16 Electrical System JD750 Crawler Bulldozer
1672-26 Alternator, Regulator and Charging System Wiring TM-l 136 (Nov-78)

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JO750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Nov-75) Lighting System 1673-1

Group 1673
LIGHTING SYSTEM

GENERAL INFORMATION
LIGHTS
REPAIR
q l

The JD75Cl Crawler Bulldozer is equipped with If a light fails to work, either the sealed beam is
gauge back lights as standard equipment. Two front- burnt out or the wiring is defective. If all the lights
and one rear-mounted canopy lights are optional won’t work, the light switch may be defective.
equipment.
The replacement sealed beam for the canopy
Refer to Section 90, Group 9015 for the wiring mounted lights is John Deere Part No. AT48364.
schematic on the lights.
The replacement bulb for the gauge back lights is
REMOVAL Trade No. 1864.

The canopy lights can be removed by disconnect-

INSTALLATION
ing the wiring lead and removing attaching hardware.
Follow removal procedure in reverse order.
To remove the sealed beam, pry the beam out of
the light housing.

To remove the gauge back lights, remove the in-

strument panel mounting screws and pull out panel. ., .

Pull light from gauge and twist bulb from socket.

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 :’ 16 Electrical System JD750 Crawler Bulldozer
.’ ‘- 16;73-2 Lighting Systems TM-1 136 (Nov-75)
:‘j
LIGHT SWITCH
GENERAL INFORMATION The light switch is a one piece sealed “ON”-“OFF”
position switch located in the instrument panel (Fig.
1).

It is a two position switch. When the switch is

pulled all the way out the lights are on, when the
switch is pushed in the lights are off.

REMOVAL
Remove screws from the instrument panel and pull
panel out. Disconnect leads from switch terminals.
Remove large hex. nut securing switch in instrument
panel and remove switch.

REPAIR
The switch cannot be repaired. Test according to
instructions in Section 90, Group 9015. Replace if
necessary.

INSTALLATION
Install light switch in instrument panel, connect
wires and install instrument panel.

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JD 750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Nov-75) Wiring Harness and Switches 1674-1

Group 1674 ‘..

WIRING HARNESS AND-SMUTCHES
WIRING HARNESS .
q
GENERAL INFORMATION
There are five main wiring harnesses in the JD750
Crawler Bulldozer.

The main harnesses are the engine wiring har-

ness, the rear harness, the right and left instrument
panel harnesses and the cab harness, if equipped.

For detailed information on the harness wiring

schematics see Section 90, Group 9015.
Fig. 2-Removing Male Connector
REMOVING BODY CONNECTORS
FROM WIRES Using a knife or a screwdriver, bend the locking
tang as shown in Fig. 2. Remove wire from connec-
To remove the body connectors is a very simple tor.
job. DO NOT attempt to jerk the wires out of the
body connectors. Use the following procedure. Be sure to bend the locking tang out when assem-
bling new body connector.

T3545lN

l-Depress the Locking 2-Reset the Locking

Tang Tang

Fig. l-Removing Female Connector

Insert a small screwdriver or paper clip into the

body connector and press the locking tang down as
shown in Fig. 1. Remove wire from connector.

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 16 Electrical Systems JD750 Crawler Bulldozer
1674-2 Wiring Harness and Switches TM- 1136 (No+75)

BATTERY DISCONNECT
The battery disconnect switch is located in the REMOVAL
right control console. The switch is wired to the bat-
On units with cab, remove front control console .
tery ground circuit.
cover. On units without cab, remove outside control
console cover. Remove handle and nut from switch.
With the switch in the “OFF” position, the battery
Remove wires from. switch and pull out switch.
ground circuit is broken so that no current will flow in
any of the electrical circuits.
REPAIR
Test the switch as described in Section 99, Group
9015. Replace the switch if found to be defective.

INSTALLATION
Follow removal procedure in reverse order.

Fig 3-Battery Disconnect Switch

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 JD750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Apr-79) Wiring Harness and Switches 1674-3

CIRCUIT BREAKERS FUSES

GENERAL INFORMATION GENERAL INFORMATION
A 30 amp main circuit breaker located behind the
instrument panel on the left side protects all the elec-
trical circuits of the crawler except the cab wiring.
A 4 amp in-line fuse located behind the key switch
protects the wiper circuit. q’
,

A 5 amp fuse located on the left control console

A 30 amp cab circuit breaker (if equipped) located cover protects the dome light and rear wiper if
behind the instrument panel on the right side protects equipped.
the cab wiring.
Prior to 307632, a 20 amp fuse located next to the 1
1 After 307632, a 30 amp air conditioning circuit dome light fuse protects the entire air conditioning
breaker located next to the cab circuit breaker protects circuit.
the air conditioning circuit.
After 307632, one 20 amp fuse located on the left 1
A 15 amp light circuit breaker located behind the console cover protects the pressurizer blower motors
instrument panel on the right protects the lighting cir- (pressurizer fuse) and another 20 amp fuse protects
cuits. the air conditioning clutch and condenser fan motors
(air conditioning fuse).
If a circuit breaker trips, it will reset itself automati-
cally.

REMOVAL
Remove instrument panel mounting screws and pull
out panel. Remove wires and attaching hardware and
remove breaker.

REPAIR
The circuit breakers are not repairable. Test as
described in Section 90, Group 9015. Replace if de-
fective.
l-Pressurizer and Air 2-Dome Light and
Conditioning Fuse Rear Wiper Fuse
INSTALLATION
Fig. 4-Fuses
Follow removal procedure in reverse order.
REMOVAL
To remove the fuses, twist the cap from the fuse-
holder and remove fuse.

REPAIR
Replace any blown fuse.

IMPORTANT: Always replace blown fuse with

one of the same size.

INSTALLATION
Follow removal procedure in reverse order.

Lifho in U.S.A.
16 Electrical Systems JD750 Crawler Bulldozer
1674-4 Wiring Harness and, Switches TM- 1136 (Apr- 79)

STARTING CIRCUIT RELAY NEUTRAL START SWITCH

GENERAL INFORMATION GENERAL INFORMATION
The starting circuit relay is located on the left side of The neutral start switch, located under the left con-
the engine. The relay allows full battery voltage to flow trol console cover, is actuated by the neutral lock lever.
to the starting motor solenoid when starting the engine. The switch enables the unit to be started in neutral
only.

Fig. ISkirting Circuit Relay

REMOVAL
Turn battery disconnect lever to “OFF” position.

Disconnect wires from each terminal and tag for

installation.

Remove screws from relay bracket and remove

Fig. d-Neutral Start Switch
relay.
REMOVAL
REPAIR
Remove left control console cover. Remove wires
The relay is not repairable. Test as described in
from switch and unscrew switch to remove.
Section 90, Group 9015.
REPAIR
INSTALLATION
The switch is not repairable. To adjust the switch,
Follow removal procedure in reverse order.
remove or add shims. Test the switch as part of starting
circuit in Section 90, Group 9015.
AIR CONDITIONING
INSTALLATION
RELAY (307632- 1
Install shims on switch and screw switch in housing.
The air conditioning relay is located under the left
Connect wires to switch.
control console cover. Battery voltage is supplied to
one of the large terminals of the relay. The other large
terminal is connected to the condenser fan motors and
compressor. Current to energize the relay is through
the normally closed high temperature switch. When the
relay is energized a connection is made between the
two large terminals.

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JO750 Crab& Bulldozer ” Electrical Systems 16
TM-7‘736 (Nov-75) Specifications and Special Tools 1699-l

Group 1699
SPECIFICATIONS AND SPECIAL TOOLS
BATTERIES, SUPPORTS AND CABLES .
q
SPECIFICATIONS AND TORQUE VALUES :’

Battery ground.................................................................. Negative

Full charge specific gravity (corrected for 80°F [27”Cl electrode temperature) 1.260 :..
Maximum variation between cells during specific gravity test (specific gravity points) . 0.050
High-rate discharge test (minimum reading per cell) . . . . . . . . 9.0 volts

When repla.cing the batteries use the John Deere battery or its equivalent shown in the following chart:

Cold
Cranking Reserve
AMPS Capacity
John Deere BCI -20°F (Minutes at
Part Number Volts Group (-EC) (-29%) 25 amps)

AU429.1.5.
(2 used) & 40 800 640 310

AT29 160
(2 used) 12 30H 570 450 180

ALTERNATOR, REGULATOR AND CHARGING SYSTEM WIRING

‘SPECIFICATIONS AND TORQUE VALUES

Rating
42 amp (With cab). 24 volt
42 amp

16 amp (Without cab) . 24 volt

16 amp

Ground (Both) .. . Negative

Stator Winding (Both). . . . Ww

1 - Brush minimum length

beyond holder (Both) . ,114 in (6.35 mm)

Fig. l-Brush Length

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16 Electrical Systems JO750 Crawler Bulldozer
1699-2 Specifications and Special Tools Ttvl- 1136 (Nov-75)

ALTERNATOR, REGULATOR AND CHARGING

SYSTEM WIRING
SPEClFlCATlONS AND TORQUE VALUES-Continued

Rotor Field Current Draw (Both alternators)

l..................... . . . . . . . . . . . . . . . . . 10 volt
2..................... . . 0.50 to 1.10 amp

Fig. P-Rotor Current Draw Test

1 - Pulley Nut (Both) . 40 to 50 lb-ft

(54 to 68 Nm) (6 to 7 kg-m)

Fig. 34Wey Nut

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JD750 Crawler Bulldozer Electrical Systems 16
TM-l 736 (Nov-75) Specifications and Special Tools 1699-3

ALTERNATOR, REGULATOR AND CHARGING

SYSTEM WIRING
SPECIFICATIONS AND SPECIAL TOOLS-Continued

l- Brush holder screws

(Both alternators). .. .16 to 20 lb-in
‘(2 ‘Ntn) (0.2 kg-m)

Fig. 4-42 Amp Alternator (with cab)

1 - Regulator mounting
screws (Both alternators) . .30 to 35 lb-in
(3 to 4 Nm) (0.4 kg)

2 - Ground and regulator

terminal nuts (Both) . . _. .35 to 45 lb-in
(4 to 5 Nm) (0.4 to 0.5 kg-m)

3 - Alternator through
bolts (Both). . .. .. . . . .30 to 35 lb-in
(3 to 4 Nm) (0.4 kg-m)

4- Rectifier diode terminal

nuts (Both) . . . . . ... .33 to 40 lb-in
(4 to 5 Nm) (0.4 to 0.5 kg-m)

Fig. 5-Rear View of 42 Amp

Alternator (with cab)

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16 Electrical Systems JD750 Crawler Bulldozer
1699-4 SDecifications and SDecial Tools TM-l 136 (Nov-751

VEHICLE LIGHTING SYSTEM

SPECIFICATIONS AND TORQUE VALUES

Front and Rear Canopy -

Mounted Lights
Rating . . . . . .. .24 volt, 80 watt
Replacement beam . . . . John Deere Part
No. AT48364

Gauge Back Lights

Rating . . . . . . . . . . . . .. . . 24 volt
Trade number replacement. . . . . . . . . . 1864

WIRING HARNESS AND SWITCHES

SPECIFICATIONS AND TORQUE VALUES

Light Circuit Breaker. . . . . . . . 15 amp

Main Circuit Breaker. . .. ... . 30 amp

Cab Circuit Breaker . .. .... .. 30 amp

Fuses
Windshield wiper ....................... .4 amp
Dome light and rear wiper .............. .5 amp
Air conditioning ....................... 20 amp

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JD750 Crawler Bulldozer Electrical Systems 16
TM- 1136 (Apr-79) Specifications and Special Tools 1699-5

BATTERIES, SUPPORT AND CABLES

SPECIAL TOOLS

Convenience Tools

Tool Tool No. Use

............ ., Hydrometer - to check

specific gravity

Fig. 6-Hydrometer

D-24001 MO Battery Tester - To check battery 1

internal condition

Fig. 743attery Tester

TY-1337 (10 amp) Battery Charger - To

TY-1338 (15 amp) charge battery and to use
TY-1339 (30 amp) as a booster to start en-
TY-1340 (100 amp) gine

Fig. B-Battery Charger

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 16 Electrical Systems JD750 Crawler Bulldozer
1699-6 Specifications and Special Tools TM- 1136 (Apr- 79)

ALTERNATOR, REGULATOR AND CHARGING SYSTEM WIRING

SPECIAL TOOLS-Continued

Tool Tool No. Use

Alternator Diode Tester - To test

diodes.

Fig. 9-Alternator Diode Tester

Essential Tools
D-19001lT Ohmmeter - To test diodes, I
brushes, rotor and stator.

Fig. IO-Voltmeter, Ohmmeter, Ammeter

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JD750 Crawler Bulldozer Electrical Systems 16
TM-1 136 (Nov-75) Specifications and Special TOOiS 1699-7

ALTERNATOR, REGULATOR AND CHARGING SYSTEM WIRING

SPECIAL TOOLS

Essential Tools-Continued

Tool Tool No. USf?

Fig. ll-A200JD Alternator Service Tool Set

1 - A-203” To install front bearings

2 - A-208* To install rotor
3 - A-213” To remove negative diodes
4 - A-214* To install negative diodes
5 - A-216” To remove bearings
6 - A-201” Used with other tools in set
7 - A-209” To install front housing
8 - A-206:” To remove positive diodes
9 - A-205* To install positive diodes

*Tools are part of A200JD Alternator Service Tool

Set and cannot be purchased individually.

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16 Electrical Systems JD 750 Crawler Bulldozer
1699-B Specifications and Special Tools TM- 1136 (Nov- 75)

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JD750 Crawler Bulldozer Frame, Chassis or Supporting Structure 17
TM-l 136 (NOW75) Main Frame 1741-1

Section 17
FRAME, CHASSIS OR SUPPORTING
STRUCTURE
CONTENTS OF THIS SECTION

Page Page
GROUP 1741 - MAIN FRAME GROUP 1746 - FRAME BOTTOM GUARDS
General Information . . . . . . . . . . . . 1741-3 General Information .. . .. .. .. 1746-l
Removal _............................. 1741-3 Removal . . . . . . . . . . 1746-l
Repair . .. . .. . . . . . . . 1741-4 Repair . .. .. . ... . . . . 1746-l
Installation ... . . . 1741-4 Installation . . . . . . . . . . . . . . . . .. 1746-l

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17 frame, Chassis or Supporting Structure JO750 Crawler Bulldozer
1741-2 Main Frame TM-I 136 (Nov-75)

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 Frame, Chassis or Supporting Structure 17
JD750 Crawler Bulldozer
Main Frame 1741-3
TM-l 136 (Nov-78)

Group 1741
MAIN FRAME
GENERAL INFORMATION Engine. ..................... Section 4
Transmission ................ Section 3
The main frame is of welded steel construction and Tracks. ..................... Section 1
is used to support the crawler components. Bulldozer frame. ............. Section 32
Cab and canopy ............. Section 18
REMOVAL
Remove components only as needed to make re-
pairs on the main frame.

Read the following sections for removal of compo-

nents:

--Q _ -

I
---%--1: 16 *?

T45366N

l-Cap Screw (4 used) 7-Lock Washer (4 used) 11-Washer (4 used)

2-Special Washer (4 used) S-Block Pad 12-Bottom Cover (2 used)
3-Engine Mount (4 used) 9-Shim (4 used) 13-Retainer (2 used)
4-Main Frame lO-Cap Screw M-Lock Washer (4 used)
?&Cover 15-Cap Screw (4 used)
6-Cap Screw (4 used) 16Special Washer (4 used)

Fig. I-Main Frame

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17 Frame, Chassis or Supporting Structure JD750 Crawler Bulldozer
1741-4 Main Frame TM-l 136 (Nov-78)

REPAIR INSTALLATION
If welding is needed for repair, have a qualified Reverse removal procedure for installation of com-
welder do the repair. Use of an E-7018 electrode is ponents.
recommended.
If the 4 shims (S,,f?g. 1) are not required between
If cracking is at a welded point of connection, grind pad block (8) and crossbar, place the reriiaining
weld down to clean metal before making a new weld. shim(s) under pad block to saddle screw washers (11).

Coat threads of cap screws (10, Fig. 1) with T43512

John Deere Loctite Thread Lock and Sealer or equiv-
alent. Torque cap screws to 170 lb-ft (230 Nm) (24
kg-m). .

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JD750 Crawler Bulldozer Frame, Chassis or Supporting Structure 17
TM- 1136 (Nov-75) Frame Bottom Guards 1746-1

Group 1746
FRAME BOTTOM GUARDS
GENERAL INFORMATION REPAIR
The front and rear bottom guards are of reinforced The bottom guards are subject to damage. Repair or
steel construction and used to protect crawler compo- replace as necessary as the guards are important in
nents. protecting crawler components.

REMOVAL INSTALLATION
Support the bottom guards using a floor jack. Re- Reverse removal procedure.
move cap screws. Slowly lower floor jack only enough
to pull guard from under the crawler. Doing this will give
you control of the guard if it is not centered on the jack
pad.

l-Front Bottom 4-Cover

2-Washer (12 used) 5-Lock Washer (2 used)
3-Cap Screw (12 used) 6-Gap Screw (2 used)

Fig. l-Front Bottom Guard

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 JO750 Crawler Builds&
17 Frame, Chassis or Supporting Structure
TM- 1136 (Nov-75)
1746-2 Frame Bottom Guards

l-Rear BottOm Guard CWasher (8 used)

2-Cover 7-Rear Cover
3-Lock Washer (2 used) PWasher (2 used)
4-Cap Screw (2, used) 9-Cap Screw (2 used)
+-Cap Screw (8 used)

Fig. P-Rear Bottom Guard

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JD750 Crawler Bulldozer Opera tar’s Station 18
TM- 1136 (Apr- 79) Safety Equipment 1806-l

Section 18
OPERATOR’S STATION
CONTENTS OF THIS SECTION
Page Page
GROUP 1806 - SAFETY EQUIPMENT GROUP 1824 - EXTERNAL ENGINE
General Information ................... 1806-3 SPEED CONTROL
Removal ............................. 1806-3 General Information . . . . . . . . . . . . . . 1824-1
Repair ............................... 1806-3 Removal . . . ... ..... .. . . 1824-l
Installation ............................ 1806-3 Repair ....................... ...... 1824-5
Installation .................... ...... 1824-5
GROUP 1808 - COMFORT AND
GROUP 1830 - HEATING AND AIR
CONVENIENCE ITEMS
CONDITIONING
General Information . . . . . . . . . . . . . . 1808-l
Heating System
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1808-l
Heater Valve
Repair .. . ........ . ...... .. 1808-l
General Information ......... ...... 1830-
Installation . . ....... .... . . 1808-l
Removal ................... ...... 1830-
Repair ..................... ...... 1830-
GROUP 1810 - OPERATOR ENCLOSURE
Installation ............... . ... 1830-l
General Information ................... 1810-l
Heater Core
Removal
General Information ....... ...... 1830-2
Cab ............................... 1810-l
Removal ................. ...... 1830-2
Windshield Washer. ................. 1810-3
Repair ................... ...... 1830-3
Window Wipers ..................... 1810-3
Installation ............... ...... 1830-4
Repair
Heater Blowers ............. ...... 1830-4
Cab ............................... 1810-4
Heater Pipes and Hoses. .... ...... 1830-4
Windshield Washer. ................. 1810-5
Air Conditioning System
Window Wipers ..................... 1810-6
Compressor
Installation ............................ 1810-6
General Information ....... ...... 1830-5
Removal ................. ...... 1830-7
GROUP 1821 - SEAT
Repair ................... ...... 1830-8
General Information ................... 1821-1
Installation ............... ..... 1830-20
Removal ............................. 1821-3
Thermal Fuse and Superheat
Repair ............................... 1821-4
Shut-off Switch
Installation ............................ 1821-11
General Information ....... . 1830-22
Removal ................. ... . 1830-22
GROUP 1823 - INSTRUMENTS AND
Repair ................... ... . 1830-22
INDICATORS
Installation ............... ... 1830-22
General Information . . . . . . . . . . . . . 1823-l
Condenser
Mechanical Instruments and Indicators
General Information ....... . 1830-23
General Information . ... ......... 1823-l
Removal ................. .. 1830-23
Removal ... ...... ........... 1823-3
Repair ................... . 1830-24
Repair . .... ... . ... .. ... 1823-3
Installation ............... . .. 1830-24
Installation. .. . .. .... .... .. 1823-3
Receiver-Dryer
Electrical Instruments and Indicators ._
General Information ....... ..... 1830-24
General Information . . . . . . . . . . 1823-4
Removal ................. ... . 1830-25
Removal .._...................... .. 1823-6
Repair ................... ..... 1830-25
Repair . .... .... .. .. .... .. 1823-6
Installation ............... . 1830-25
Installation. . . . . . . . . . . . . . . . . . . . . . 1823-6
Evaporator
General Information ....... . . . 1830-26
Removal ................. . . . . . 1830-26
Repair ................... . . 1830-26
Installation ............... . . 1830-26

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18 Operator’s Station JD750 Crawler Bulldozer
1806-2 Safe& Equipment TM- 1136 (ADr- 79)

Page Page
GROUP 1830 - HEATING AND AIR GROUP 1899 - SPECIFICATIONS AND
CONDITIONING-Continued SPECIAL TOOLS
Regulatory Controls Specifications and Torque Values
Expansion Valve Comfort and Convenience Items. . .. 1899-1
General Information ............... 1830-27 Operator Enclosure. . . . . . . . . . . . . . . . 1899-1
Removal ......................... 1830-27 Instruments and Indicators ..... ._ .. 1899-2 1
Repair ........................... 1830-27 External Engine Speed Control . _. .. 1899-3
Installation ....................... 1830-27 Air Conditioning System . . . . . . . . . .. 1899-4
Thermostatic Temperature Special Tools
Control Switch Air Conditioning System . . . . . . . . . . . 1899-6
General Information ............... 1830-28
Removal ......................... 1830-28
Repair ........................... 1830-29
Installation ....................... 1830-29
Compressor Relief Valve
General Information ............... 1830-29
Removal ......................... 1830-29
Repair ........................... 1830-29
Installation ....................... 1830-29
Refrigerant Couplings
General Information ................. 1830-30
Disassembly. ....................... 1830-30
Repair ............................. 1830-30
Assembly .......................... 1830-30
High Temperature Switch
General Information ................. 1830-31
Removal ........................... 1830-31
Installation .......................... 1830-31
Air Intake System
Pressurizer Blowers and Switch
General Information ............... 1830-32
Removal ......................... 1830-32
Repair ........................... 1830-33
Installation ....................... 1830-33
Air Filters .......................... 1830-33

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JO750 Crawler Bulldozer Operator’s Station 18
TM-1 136 (Nov-75) Safety Equipment 1806-3

Group 1806
SAFETY EQUIPMENT
GENERAL INFORMATION REMOVAL
The horn is located under the grille at the upper left To remove the horn, remove grille. Disconnect wir-
of the crawler. ing lead, attaching hardware and remove horn.

The horn is controlled by the horn switch located on

the instrument panel.
To remove horn switch, remove instrument
mounting screws and pull out panel.
panel
;
q
Remove rubber cover on switch. Remove nut on
switch.
c .
Disconnect wire from rear of switch and pull switch
from rear of panel.

REPAIR
The switch or horn are not repairable.

Test as described in Section 90, Group 9015.

INSTALLATION
Follow removal procedure in reverse order.

1-Horn P-Horn Switch

fig. 1-Horn

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18 Operator’s Station JD750 Crawler Bulldozer
__~~
1806-4 Safetv EauiDment TM-l 136 (Nov-75)

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JD750 Crawler Bulldozer Operator’s Station 18
TM-1 136 (Nov-751 Comfort and Convenience Items 1808-I

Group 1808
COMFORT AND CONVENIENCE ITEMS
GENERAL INFORMATION REMOVAL
A 12-volt cigar lighter is located on the instrument To remove the cigar lighter, remove the instrument
panel. panel mounting screws and pull out panel. Remove the
cigar lighter element.

Disconnect wires and remove housing clamping

shell and housing.

To remove resistor, remove wires, attaching hard-

ware and remove resistor.

REPAIR
The cigar lighter and the resistor cannot be repaired.
Test as described in Section 90, Group 9015. Replace
if defective.

Fig. l-Cigar Lighter

INSTALLATION
To install the lighter, place housing in opening, in- i
A 1.5 ohm resistor located on a bracket behind the stall housing clamp in shell and connect wire. Install
right side of the instrument panel reduces the machine element and replace instrument panel.
24 volts to 12 volts used by the lighter.

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18 Operator’s Station JD750 Crawler Bulldozer
1808-2 Comfort and Convenience /terns TM: 1136 (Nov- 75)
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Operator Enclosure 1810-l

Group 1810
OPERATOR ENCLOSURE
GENERAL INFORMATION Prior to ser. no. 307632, disconnect air conditioning I
lines at refrigerant couplers (Fig. 2). Cap lines.
The JD750 has a ROPS (Roll-Over Protective
Structure) canopy or a cab with ROPS.

The cab on machines before ser. no. 307632 is a

two-door cab: later cabs are one-door cabs.

REMOVAL
Cab
NOTE: The following removal story is for units prior
to ser. no. 307632. On later units, the heater and air
conditioning lines can be left connected.
To remove cab, disconnect heater hoses at engine
as the shut-off cocks shown are no longer used. The
air conditioning system must be discharged (Group Fig. Z-Air Conditioning Lines
9031) prior to disconnecting lines at the compressor as
the quick disconnects (Fig. 2) are no longed used. Disconnect the negative ground wire.
NOTE: If the shop facility has only a stationary
hoist, position the crawler under the hoist so the front Disconnect hydraulic control valve linkage.
turning point of the ROPS is directly under the hoist.
Disconnect the wiring harnesses at the splitter
Remove muffler extension and muffler. housing.
Remove floor boards.
Remove the cap screws holding the rear end of the
Disconnect the engine speed control cable, for- ROPS to the crawler.
ward-reverse speed control cable, brake release valve
cable, return-to-neutral cable, transmission automatic Remove locking cap screws (1, Fig. 3).
control valve shut-off cable and clutch disconnect
The ROPS can have lifting eyes (Fig. 4). If so, use
the eyes to tilt the cab.

If the ROPS does not have the lifting eyes, lift cab
enough so it can be blocked. Then install lifting eyes at
opposite end attaching holes.

CAUTION: Wire hooks so they will not

A come loose as chain can loosen as cab is
tilted past center.

Fig. l-Cab Heater Shut-Off Cocks ( -30763 1)

Close the four cab heater shut-off cocks (Fig. 1) and

disconnect hoses.

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18 Operator’s Station JD750 Crawler Bulldozer
1810-2 Operator Enclosure TM- 1136 (Apr- 79)

T44803N

Fig. 4-ROPS with Lifting Hooks

~7448021

l--Cap Screw 4-ROPS Front

2-Locking Hole Member
3-4OPS Lower 5-Pin
Member 6-Pin Retainer

Fig. 3-ROPS Locking Location

If the shop facility has a movable hoist, move the

hoist as the cab is tilted. This will prevent the chain
from loosening.

When the cab goes past center, install cap screws

(1, Fig. 3) through front member (4) into hole (2)to hold
cab in tilted position.
Fig. 5-Transmission Control Valve
Remove the transmission control valve (Fig. 5). Do
not disconnect oil lines from the valve unless it is
To remove cab from crawler, fasten chains at the
necessary to service the valve.
four corners of the ROPS (Fig. 6).

Remove locking cap screws and lower cab.

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JD750 Cm wler Bulldozer Operator’s Station 18
TM-1 136 (Nov-78) Opera for Enclosure 1810-3

Window Wipers

-8

T62352N T42220

Fig. 6-Cab Lifting Locations

l-Nut 7-Wiper Arm
2-Spacer S-Wiper Blade
Remove locking cap screws (1, Fig. 3). pin retainer
3-Washer 9-Special Nut
(6) and pin (5). Lift cab from crawler. 4-Lock Washer lo--Outer Spacer
F&Machine Screw 1 l-Gasket
Block the‘cab off the floor to prevent damaging &Wiper Spacer 12-Wiper Motor
cables and linkages.
Fig. 7-Rear Window Wiper

Windshield Washer
Refer to Figs. 7 and 8 for removal of the window
Remove attaching hardware and disconnect electri- wipers.
cal conductor and remove motor or resistor.
Remove the panel under the instrument panel for
access to the windshield wiper motor.

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 18 Opera tar’s Station JO750 Crawler Bulldozer
1810-4 Operator Enclosure TM-l 136 (Nov-78)

:
In

T43057

l-Special Nut Ii-Cap Nut 22-Bracket

2-Special Screw 12-Lock Washer 23=-Screw and Lock Washer
3-Wiper Arm KG-Knurled Driver Nut (2 used)
4-Wiper Blade M-Rain Shield Cap 24-Spring Clip (2 used)
!&Acorn Nut 15-Special Nut 25-Special Washer (2 used)
g-Special Washer 1 GSpecial Washer 26--Connecting Link
7-Gap Screw (2 used) 17-Leather Washer 27-Nut and Lock Washer
g-Gasket 10rank Pin 2&-Drive Assembly Arm
g-Assembly Plate 1 g-Lock Was her 24-Bowed Washer
lo-Screw and Lock Washer 20-Nut 30-Wiper Motor
(3 used) 21-Shah and Pivot
Assembly

Fig. d-front Windshield Wiper

REPAIR Fit the glass in the other four-sided opening of the

molding.
Cab
Look at Fig. 9 for typical cab components. Put the filler strip (3) into the molding to hold the
glass in place.
Note how glass is installed in the cab. Install the
glass molding (2, Fig. 9) around the edge of the win-
dow frame. The rounded side of the molding faces the
inside of the cab. The larger four-sided opening of the
molding fits over the edge of the window frame.

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 JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Operator Enclosure 1810-5

T44606N

l--Side Window Glass bFront Windshield Glass

2-Glass Molding 5-Lower Front Glass (2 used)
3-Filler Strip 6-Gab

Fig. g-Cab Assembly

Windshield Washer The electrical components cannot be repaired. Test

as instructed in Section 90, Group 9015.
The windshield washer uses a 12 volt motor. A
resistor, found to the right of the windshield washer, is
electrically connected between the windshield washer
1 and windshield wiper. The resistor cuts down the ma-
chine 24 volts to 12 volts for the motor.

‘tithe in U.S.A.
 ” .,
16 ,. Operator’s Station JD750 Crawler &&lozer
1810-6 Operator Enclosure TM- 1136 (Apr- 79) - -.

Window Wipers Refer to Fig. 10 and torque cap screws as follows:

Wiper motors cannot be repaired; they must be
l/2” x l-1/4” cap screws (key 1) torque to 120 lb-ft
replaced if defective.
(163 Nm) (17 kg-m), 3/4” x 2-3/4” and 3/4” x 2-112”
cap screws (keys 2 and 4) torque to 425 + 43 lb-ft (576
Check linkage for worn, bent or broken conditions.
2 58 Nm) (59 c 6 kg-m).
Replace parts as necessary.

7/8” x 2” cap screws (key 3) torque to 685 ? 68 lb-ft

INSTALLATION
(929 t 92 Nm) (95 t 7 kg-m).
For cab installation, reverse the removal procedure.
Look at Figs. 7 and 8 for installation of the window
wipers.

2’62353N

1 l---1/2” x l-114” Cap Screw 3-718” x 2” Cap Screw

(6 used) (8 used)
2-3/4” x 2-314” Cap Screw 4-314” x 2-l/2” Cap Screw
l--Rear Support 2-ROPS Rear Support
(4 used) (8 used)
Front Plate (L.H. Shown)

Fig. IO-Cap Screws Torque

Fig. 1 l- ROPS Rear Support and
Front Plate

If shims were removed from between ROPS rear

support and front plate, reinstall them to avoid move-
ment between support and plate.

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JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Seat 1821-1

Group 1821
SEAT
GENERAL INFORMATION The seat cushion, backrest and armrests are all
adjustable.
The crawler may be equipped with a suspension or
non-suspension seat.

A foam padded seat, backrest and armrests are

provided as regular equipment.

l-Tilt Plate (2 used) flilt Latch

2-Machine Screw (2 used) I-Armrest (2 used)
3-Backrest Cushion &Back Tilt Bolt (2 used)
4-Seat Cushion g-Washer (2 used)
5-Nut (2 used) IO-Spring Washer (2 used)
11-Washer (2 used)

Fig. l-Seat Cushions with Tilt Latch ( -283423)

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18 Operator’s Station &X50 Crawler Bulldozer
1821-2 Seat TM- 1136 (Apr- 79)

l-Armrests (2 used) GSpring Washer (2 used)

2-Tilt Plate (2 used) 7-Back Tilt Bolt
3-Screw (2 used) &Seat Cushion
4-Backrest Cushion g-Cap
5-Washer (2 used) lo-Tilt Latch
11-Washer (2 used)

Fig. P-Seat Cushions with Tilt Latch (283424- I

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 JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Aor- 79) Seat 1821-3

T62534F

1 l-Cap Screw (22 used) 9-R.H. Armrest Bracket 17-Washer (2 used)

2-Lock Washer (20 used) 1 O-Washer l&Rear Seat Support
3-Seat Base 1 l-Washer 19-L.H. Armrest Bracket
4-Seat Hold-Down 12-Nut 20-Cap Screw (2 used)
!5--Cap Screw (4 used) 13-Special Washer (4 used) St-Seat Hold-Down Bracket
6-Bumper U-Special Screw (4 used) 22-Spring
7-Gap Screw (4 used) 15-R.H. Support 23-Cap Screw
&Hinge 16L.H. Support 24-Seat Panel

Fig. 3-Seat Supports (Without Cab)

Remove only enough parts to make repairs. Refer to the figures in this group for parts locations.

Litho in U.S.A.
 18 Operator’s Station JD750 Crawler Bulldozer
1821-4 Seat TM- 1136 (Apr- 79)

REPAIR

q:

l-Cap Screw (4 used) 4-Spring 6-Lock Washer (6 used)

2-Lock Washer (4 used) 6-Cap Screw g--Cap Screw (6 used)
3-Seat Hold-Down Support 6-Seat Hold-Down lo-Front Seat Support Plate
(2 used) 7-Seat Plate

fig. 4-Seat Plate and Hold-Down (With Cab)

1

T43135

l-R.H. Side Bracket 4-Shoulder Bolt (4 used)

2-L.H. Side Bracket S-Adjustment Link
3-Cable (2 used)

fig. 5-Seat Adjustment Link and Side Brackets ( -283423)

Litho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Seat 18214

:
m
l-Shoulder Bolt (2 used) 5-Gable (2 used)
2-R.H. Side Bracket 6-Washer (2 used)
3-Spacer Bar 7-Link
4-L.H. Side Bracket

Fig, d-Seat Adjustment Link and Side Brackets (283424- )

inspect all parts for broken or bent conditions. Re- Replace any spring that appears stretched.
place parts as necessary.

Bent rods and adjusting mechanisms should be

replaced, as binding could occur when the seat is
adjusted.

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 18 Operator’s Station JD750 Crawler Bulldozer
1821-6 Seat
TM- 1136 (A pr- 79)

l-R.H. Slider Block GLatch Rod W--Slide Bearing (4 used)

2-L.H. Slider Block ‘I-Slide Latch 1 l-Handle Cap
3-Lower Housing g--Base Plate Slide 12-Instruction Decal
4-Latch Handle %-Slide Bearing (4 used) 13-Suspension Boot
5-Tension Spring (2 used)

I Fig. 7-Seat Adjuster Assembly (Suspension Seat) ( -283423)

Litho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Seat 1821-7

.2'66203N

I-Litt to Side Cap g-Tension Spring 1 l-instruction Decal

2-Slide Stop Bolt 7-L.H. Slide Latch 12-Latch Link
3-Lower Housing B-Slide Track 13-Slide Latch Lever
4-Gable Q-Roller (4 used) 14-Suspension Boot
6-R.H. Slide Latch W--Ride Height Indicator

Fig. 8-Seat Adjuster Assembly (283423- !

Litho in lJ.S.A:
18 Operator’s Station JD750 Crawler Bulldozer
1821-8 Seat TM- 1136 (Apr- 79)

l-Upper Housing Plate !&Handle Cap g--Slide Latch

Z&Lower Housing GLatch Handle lo--Base Plate Slide
3-Splicer Assembly 7-Tension Spring (2 used) 11-Slide Bearing (4 used)
4-Bearing Shaft B-Latch Rod ll-Slide Bearing (4 used)
13-Connecting Link

Fig. B-Seat Adjuster Assembly (Non-Suspension Seat)

bitho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Seat 1821-9

T43119

i-Outer Arm 4-Bearing Shaft GBearing Shaft

2-Cross Pivot Bearing (2 used) r&-Tube Bearing (4 used) 7-Inner Arm
3-Cross Pivot Tubs (2 usad)

Fig. lo-ScissorsSuspension Arms with Shafts

(Suspension Seat) ( -283423)

Litho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1821-10 Seat TM- 1136 (Apr-79)

ItI/
T61202F r3 \ 4---%
l-Upper Housing Bearing S-Cross Pivot Bolt (2 used) g-Inner Arm
2-Outer Arm 6-Bearing Shaft lo-Lower Housing Bearing
3-Gross Pivot Bearing (2 used) 7-Tube Bearing (4 used) 1 l-Bearing Shaft
4-Thrust Washer (2 used) 8-Spring (2 used)

Fig. 7 l-Scissors Suspension Arms with Shafts

(Suspension Seat) (283424- )

bitho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM-l 136 (Apr-79) Seat 1821-11

T66204N

l-Upper Housing Plate g-Gear and Shaft Assembly 17-Pivot Nut

2-Spacer Tube lo--Gear and Shaft l&Adjustment Shaft
3-Shock Absorber 11 -Outer Arm 19-Height Adjustment Knob
4-Special Shoulder Bolt 12-Slider Block 20-Height Decal
5-Shock Absorber Bearing 13-Bumper (2 used) Pl-Connecting Link
(2 used) 14-Weight Adjusting Knob 22-Special Washer (2 used)
GSpring Pad 15-Weight Decal 23-Thrust Washer (2 used)
7-Conical Spring 16Slider Block
g-Spring Washer

Fig. 12-Scissors Suspension Housing with Spring and Shock Absorber

(Suspension Seat) ( -283423)

INSTALLATION
Refer to Figs. 1 through 13 to aid in assembly and
installation of the seat.

Litho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1821-12 Seat TM- 1136 (Apr- 79)

18
17
15 ,c \ \
-\

\ LO

Q-\

T66518

l-Notched Link 7-Spring Pad 13-Outer Arm

2-Upper Housing Plate 8-Spring Washer 14-Spinner
3-Connecting Link g--Gear and Shaft Assembly 16-Height Adjustment Cap
4--T&e Bearing lo-Bumper (2 used) 1 GLever
6-Shock Absorber 11-Shock Absorber Bearing (2 used) 17-Latch Return Spring
6-Conical Spring 12-Gear and Shaft 1&Latch

Fig. 13-Scissors Suspension Housing with Spring and Shock Absorber

(Suspension Seat) (283424- )

Litho in U.S.A.
 JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) instruments and Indicators 1823-l

Group 1823
INSTRUMENTS AND INDICATORS
GENERAL INFORMATION See Section 5, Group 0505 for the start aid switch.

There are both mechanical and electrical instru-

See Section 16, Group 1673 for the light switch.
ments and indicators on the JD750 Crawler.

See Section 18, Group 1806 for the horn switch.

The engine water temperature gauge, engine oil
pressure gauge, transmission oil temperature gauge,
See Section 18, Group 1808 for the cigar lighter.
transmission oil pressure gauge and air restriction
indicator are mechanical.
MECHANICAL INSTRUMENTS AND
INDICATORS
The voltmeter, hour meter, equipment oil filter indi-
cator light, transmission oil filter light, horn, wiper,
General Information
starter, key, light and start aid switches, cigar lighter
and cab relay are electronically operated.
Transmission Oil Pressure Gauge

7-Transmission Oil
I l-Engine Water
Temperature Gauge
2-Horn Switch
Pressure Gauge
9-Hour Meter
3-Hydraulic Oil Filter g--Starting Aid Switch
Indicator Light 19-Light Switch
4-Engine Oil Pressure 1 l-Cigar Lighter
Gauge 12-Key Switch
5-Transmission Oil 13-Wiper Switch
Temperature Gauge U-Starter Switch
GTransmission Oil l!+Voltmeter T43767N
Filter Indicator Light
l-Red-Orange 3-Light Green
Fig. 1-Instrument Panel
2-130 psi (9 bar) (9 kg/cma)

Fig. P-Transmission Oil Pressure Gauge

An oil filled tube leads from the transmission oil

pressure gauge to the transmission. The oil pressure in
this tube will be sensed by the gauge and indicated on
the gauge face.

The gauge indicates pressure from 0 psi to 300 psi

(0 to 21 bar) (0 to 21 kg/cm2). The normal operating
range is indicated by the light green area on the gauge
face (130 psi to 300 psi [9 to 21 bar1 [9 to 21 kg/cm?).

Litho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1823-2 Instruments and Indicators TM- 1136 (Apr- 79)

Transmission Oil Temperature Gauge Engine Water Temperature Gauge

T38473N
l-l 00°F (36°C) 5-224°F (107°C)
2-Black 6-Red-Orange
3-l 60°F (71 “C) 7-250°F (121 “C)
4-Light Green

T43768N Fig. 4-Engine Water

Temperature Gauge
l-l 25°F (52°C) 4-200°F (93%)
2-Light Green 5-Red-Orange The engine water temperature gauge indicates the
3-150°F (66°C) 6-225’F (107°C) temperature of the cooling system.
Fig. 3-Transmission Oil
Temperature Gauge The gauge indicates temperatures from 100“ to
300°F (38” to 149°C).
The transmission oil temperature gauge measures
the temperature of the oil in the transmission. Normal operating temperature is indicated by the
light green zone (160” to 224°F 171’ to 107”Cl).
The gauge indicates temperatures from 0” to 250°F
(- 18” to 121°C). The normal operating range is indi-
cated by the light green area on the gauge face (0’ to
200°F [- 18” to 93”Cl).

Litho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Instruments and Indicators 1823-3

Engine Oil Pressure Gauge Removal

Remove the instrument panel mounting screws and
pull out panel.

Remove gauge back light, mounting hardware and

disconnect sending tube. Remove gauge by pulling out
of front of instrument panel.

d:
Repair
The gauges are not repairable.

Test the transmission oil pressure as described in

Section 90, Group 9026. I

Test the engine oil pressure as described in Section

90, Group 9010.

The engine water temperature and transmission

T34798N
temperature gauges can be tested by substituting a
l-Red-Orange 3-25 psi (2 bar) known good gauge or testing the temperature of the
2-10 psi (1 bar) (2 kg/cmz) engine cooling system or transmission reservoir.
(1 kg/cm*) 4-Light Green
Installation
Fig. 5-Engine Oil Pressure Gauge
Replace gauge by installing in instrument panel,
An oil filled tube leads from the engine oil pressure connecting tube, attaching mounting bracket and in-
gauge to the engine block. The oil pressure in this tube stalling instrument panel.
will be sensed by the gauge and indicated on the
gauge face. Tighten all gauge to fitting connections to 40 - 50
lb-in (4.5 - 5.6 Nm) (0.46 - 0.58 kg-m) with a minimum
The gauge indicates pressure from 0 psi to 80 psi (0 of 2.3 turns.
to 6 bar) (0 to 6 kg/cm2). The normal operating range is
indicated by the green area on the gauge face (25 psi Tighten all gauge mounting hardware to 8 - 12 lb-in
to 80 psi [2 to 6 bar1 [2 to 6 kg/cm?). (0.9 - 1.35 Nm) (0.09 - 0.14 kg-m).

Air Restriction Indicator

The air restriction indicator located on the radiator
upper support shows red when the air intake system is
excessively restricted.

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18 Operator’s Station JD750 Crawler Bulldozer
1823-4 Instruments and Indicators TM- 1136 (Apr- 79)

ELECTRICAL INSTRUMENTS Hour Meter

AND INDICATORS
General Information
Voltmeter

T43770N

Fig. 7-Hour Meter

The hour meter is an electrically energized clock

T43769N
which records the number of hours the engine has
l-Orange 6-25.6 Volts operated. Starting and stopping of the clock is con-
2-22.4 Volts 6-Black trolled by the key switch “IGN” terminal.
3-24 Volts 7-26.6 Volts
4-Light Green 8-31 Volts

F/g. &Voltmeter

The voltmeter will measure the voltage of the elec-

trical system when the key switch is in the “IGN”
position.

Litho in U.S.A.
 JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Instruments and Indicators 1823-5

Hydraulic Oil Filter Light Transmission Oil Filter Indicator Light

l-Transmission Oil 34ndicator Test

Filter Indicator Pressure Switch
l-Hydraulic Oil Filter 34ndicator Test Light
I Indicator Light Pressure Switch 2-Transmission
Sending Unit
Filter
2-Equipment Oil Filter
Sending Unit
Fig. 9-Transmission Filter
Fig. &?-Hydraulic Oil Filter indicator Light
indicator Light
The transmission oil filter light will light with approx-
The hydraulic oil filter indicator light will light when- imately 5 psi (163 mbar) of vacuum indicating a res-
ever there is a pressure differential in the equipment tricted filter.
hydraulic oil filter of more than 40 psi (3 bar) (3 kg/
cm2), indicating a restriction in the filter.

NOTE: The indicator should also light with the key

on “IGN” and the engine not running.

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18 Operator’s Station JD750 Crawler Bulldozer
1823-6 Instruments and Indicators TM- 1136 (Apt-- 79)

Starter Switch Wiper Switch

The starter switch (14, Fig. 1) is a push button The wiper switch (13, Fig. 1) controls the front
switch. When the switch button is depressed with the windshield wiper and windshield washer (if equipped).
key switch in the “IGN” position and the neutral lock The wiper motor rotates to three positions (off, low and
lever up, current flows through the starter switch to the high speed). To operate the washer, the switch must
starting circuit relay, to the neutral start switch to be pushed in.
ground.
Removal
Key Switch
To remove electrical instruments or indicators lo-
The key switch (12, Fig. 1) is a one-piece sealed cated in or behind the instrument panel, remove in-
switch. strument panel mounting screws and pull out panel.

When the key is straight up and down in the switch, it Disconnect wires from instrument or indicator, re-
is in the “OFF” position. When the key is turned to the move attaching hardware and remove instrument or
left, the “ACC” terminal is energized, and when the key indicator.
is turned to the right, the “IGN” and “ACC” terminals
are energized. Repair
The instruments and indicators located in or behind
Cab Relay
the instrument panel cannot be repaired.
The cab relay (if Equipped) is located behind the
instrument panel. When the key switch is on “IGN”, Test as described in Section 90, Group 9015.
voltage is fed through the relay to the various switches
for the cab accessories. Replace if found to be defective.

Installation
Follow removal procedure in reverse order.

Tighten all gauge mounting hardware to 8 - 12 lb-in

(0.9 - 1.35 Nm) (0.09 - 0.14 kg-m).

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JD 750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Nov-75) External Engine Speed Control 1824-l

Group 1824
EXTERNAL ENGINE SPEED CONTROL
GENERAL INFORMATION REMOVAL
The speed control system consists of a hand control Refer to Figs. 1, 2, 3,4 and 5 when removing speed
lever which is connected to the injection pump by control linkage components.
means of control cable and linkage.
1,

ENGINE SPEED
CONTROL SHAFT
AND LEVERS

T44731

l-Cap Screw 7-Gable 13-Nut (3 used)

2-Clamp (4 used) E-Cap Screw 14-Spacer (2 used)
3-Gable Support “Washer (2 used) 1!5-Lock Washer (2 used)
4-Cap Screw (2 used) lO-Cap Screw (2 used) 16-Fuel Injection Pump
!&Ball Joint (2 used) 1 l-Cable Support Lever
6-Jam Nut (3 used) 12-Special Washer (3 used)

Fig. l-Engine Speed Control Cable and Supports

Litho in U.S.A.
18 Operator’s Station JO750 Crawler Bulldozer
1824-2 External Engine Speed Control TM-1 136 (Nov-75)

CONTROL
SUPPORT
LEVER

CROSS

ENGiNE
SPEED TRANSMISSION AUTOMATIC
CONTROL CONTROL VALVE
CABLE LINKAGE

T44743

l-Nut (2 used) +-Ball Joint (2 used) g-Set Screw (2 used)

2-Lock Washer (2 used) S-Rod Assembly lo--Nut (2 used)
3-Cable Lever 7-Gap Screw (2 used) 11-Lever (2 used)
4-Jam Nut (2 used) S-Bearing (2 used) 1P-Cross Shafl

Fig. P-Engine Speed Control linkage Cross Shaft and Levers

Litbo in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM-l 136 (Nov-75) External Engine Speed Control 1824-3

:
q
FORWARD AND REVERSE
SPEED CONTROL LEVER
LINKAGE

CONTROL LINKAGE
T44744
1-E-t Screw(4 used) 5-Bearing (4 used) g-Shaft
2-Jam Nut (4 used) GCap Screw (4 used) 1&Shaft
3-Lever (2 used) 7-Lock Washer (4 used) 11-Lever (2 used)
4-Plug (2 used) &Complete Control Support

Fig. 3-Engine Speed Control Support

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18 Operator’s Station JD750 Crawler Bulldozer
1824-4 External Engine Speed Control TM- 1136 (Nov- 75)

SPEED CONTROL

SPEED CONTROL
SUPPORT LEVER

7
8

l-Knob 5-Control Arm 9-Cap Screw (2 used)

2-Throttle Lever 6-Pin lo-Ball Joint (2 used)
3-Cap Screw 7-Nut (2 used) ll-Jam Nut (2 used)
4-Lock Washer &Lock Washer (2 used) 1 P-Rod Assembly

Fig. 4-Throttle lever and Control Arm

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JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Mar-78) External Engine Speed Control 1824-5

T42783 8

l-Seal Ciate &Facing (6 used)

2-Dowel GSpring (3 used) g-Separator Plate (2 used)
3-Housing 7-Pressure Plate 1 t&Shaft
4438 Screw (3 used)

Fig. 5-Engine Speed Control Head

REPAIR INSTALLATION
Refer to Figs. 1 through 5 for repair of the speed Refer to Fig. 5 for speed control head installation.
control linkage.
Apply T43512 John Deere Loctite Thread Lock and
Replace any parts that are worn or seem question- Sealer or equivalent to the tapped holes of the housing
able. Parts should move freely. (3). Assemble the set screws (4) flush with the inside
wall of the housing.

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 18 Operator’s Station JD750 Crawler Bulldozer
1824-6 External Engine Speed Control TM- 1136 (Mar-78)

Lubricate shaft (10, Fig. 5) and assemble shaft into Install separator plate (9) and install second set of
speed control head housing. facings (8).

Install plate (5). Install the springs (6) alternating the Install separator plate and install third set of facings.
dish of the springs with the first spring installed with the
inside dished out away from the seal (1). Adjust speed control head set screws (4) evenly. 1
When set screws are tightened properly, a force of 19
Install pressure plate (7). + 2 lb. (85 t 9 N) (9 & 1 kg) is required to move the
lever. Measure the force with a spring gauge hooked

m Install first set of facings (8) one on each dowel. right below the knob (1, Fig. 4).
:
Refer to Section 90, Group 9026 and do the follow-
ing procedures:

Procedure 3 - FNR speed control lever linkage

neutral adjustment.

Procedure 4 - Engine speed and transmission

control valve synchronization.

Litho in U.S.A.
JD750 Crawler Bulldozer Operatofs Station 18
TM- 1136 (Nov-75) Heating and Air Conditioning 1830-l

Group 1830
HEATING AND AIR CONDITIONING
HEATING SYSTEM
HEATER VALVE Removal
General Information
The heater valve is a device for controlling engine
Turn off heater shut-off cocks located
extreme right hand floorboard.
under the
:
q
coolant circulation in the heater core. Opening the
Remove right-hand control console cover
valve allows coolant to circulate through the core, while
the pressurizer blowers draw in air through the heater
Disconnect the valve inlet and outlet hoses.
core to give the desired heating effect.
Remove cable from control knob to control valve and
The quantity of coolant flowing through the valve
remove valve.
depends upon the control setting, varying from no flow
to maximum flow.
Repair
A control knob located on the right-hand console The valve is not designed to be repaired internally. If
cover regulates the valve. the valve fails to shut the coolant off completely or
otherwise fails to perform properly, replace with a new
one.

Be sure the heater hoses are correctly connected to

the engine. If hoses are reversed, a satisfactory heater
valve will not operate properly, and may be damaged.

Installation
Reverse the removal steps, making sure the hose
clamps properly seal hoses to prevent leaking.

Fill cooling system. Start engine and check for

proper operation.

fig. l-Heater Control Knob

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18 Operator’s Station JD750 Crawler Bulldozer
1830-2 Heating and Air Conditioning TM-1 136 (Nov-75)

HEATER CORE
General Information Removal
The heater core, located under the climate control Turn off the heater shut-off cocks located below and
cover at the rear of the cab, is constructed of aluminum in front of the right control console cover.
and is similar to a cooling system radiator.
Remove the right and left control console covers.
The pressurizer blowers draw air through the heater
core and blow the air through the air outlets into the Remove the climate control cover.
cab.
Disconnect and tag heater core inlet and outlet
Approximately sixty percent of the air flow through hoses.
the heater and air conditioner evaporator (if equipped)
comes from outside the cab. The remainder of the air Remove the hardware attaching heater core and
flow is recirculated inside the cab through the filter remove core.
under the climate control cover.

Litho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Nov-75) Heating and Air Conditioning 1830-3

Repair If the core cannot be satisfactorily repaired, replace

with new core.
‘The heater core should be tested for leaks whenever
a repair is made. Cap or plug the outlet and apply air
Fins should be straight and free from obstructions.
pressure at 15 psi (1 bar) (1 kg/cm*) to the inlet
opening to test.

12

- I
‘I
I.2 -. I
A’, CYLIFIDE'( I
,I , I! i
BLOCK ,If',' I'

T43774N

l-Knob 9-Heater Line l&Adapter

2-Grommet lO-Heater Line 19-Hose (90-112 in.
3-Heater Valve Control Cable ll-Hose (3 used) [2 300 mm1 long)
4-Hose Clamps (18 used) 12-Heater Core 20-Hose (58 in.
5-Heater Hose (37 in. 13-Shut-Oft Cock (4 used) [l 473 mm1long)
1940 mm] long) M-Hose (2 used) (g-318 in. Pl-Clamp
6-Grommet (2 used) [238 mm1 long) 22-Heater Block
7-Heater Hose (38-112 in. 15-Cap Screw (2 used) 23-Lock Washer (2 used)
I978 mm3 long) 16Special Connector 24-Nut
&Heater Valve Assembly 17-Band (4 used) 25-Floor Heater Block

Fig. a-Heater and Heater Hoses

Litho in U.S.A.
 18 Opera tar’s Station JD750 Crawler Bulldozer
1830-4 Heating and Air Conditioning TM- 1136 (Nov-75)

Installation HEATER BLOWERS

Follow removal procedure in reverse order. See Fig. Forced circulation of the heated air is accomplished
2 to aid in installation. by the pressurizer blowers (see page 18-1830-28).

Turn on heater shut-off cocks. HEATER PIPES AND HOSES

Carefully inspect the heater system pipes and hoses
Fill the cooling system as required. Start the engine
(Fig. 2) for possible sources of trouble whenever a
and run long enough to make sure that all air has been
repair is made on the system.

q:
purged from the system.
All connections should be checked for prior leakage.
If air remains in the system, loosen one of the hoses
Hoses that are frayed, or otherwise appear question-
at the heater valve and allow air to escape.
able should be replaced.

Tighten the hose clamp and finish filling the cooling

system.

Litho in U.S.A.
JO750 Crawler Bulldozer Opera tar’s Station 18
TM- 1136 (Apr- 79) Heating and Air Conditioning 1830-S

AIR CONDITIONING SYSTEM

COMPRESSOR

T’48521N 018

l-O-Fling Seal g-Dust Cover 17-Main Shaft Rear Bearing

2-Piston lo--Hub and Drive Plate l&Oil Pick-Up Tube
3-Drive Ball Assembly 19-Rear Discharge Valve Plate
4-Ball Shoe 1 l--Pulley PO-Relief Valve
S--Suction Reed 12-Clutch Coil Pl-Superheat Switch (Late Units)
6-Front Discharge 13-Front Head 22-Oil Pump
Valve Plate t&Main Shaft Front Bearing 23-Rear Head
7-Shaft Seal IS-Main Shaft Thrust Bearing
&Pulley Bearing 16-Swash Plate

Fig. 3-Cross Section of Compressor

General Information An oil pump mounted at the rear of the compressor

picks up oil from the bottom of the compressor oil sump
The compressor is a horizontal 3-piston, double- and pumps the oil to the internal working parts of the
acting type (Fig. 3), and is belt-driven from the engine compressor.
water pump pulley. Operation of the compressor is controlled by the
Pistons are mounted axially around the compressor temperature control switch, which electrically controls
shaft and driven by a swash plate. the magnetic clutch on the compressor.
The compressor is fitted with a high pressore relief
Reed-type suction and discharge valves are valve which opens whenever the compressor dis-
mounted in valve plates between the cylinder as- charge pressure exceeds 440 psi (30 bar) (31 kg/cm*).
sembly and the head at each end of the compressor. On later units, there is a superheat shut-off switch
The heads are connected by gas-tight passageways mounted in the rear head of the compressor. I
which direct refrigerant gas to a common outlet.

-
Litho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1830-8 Heating and Air Conditioning TM- 1136 (Apr- 79)

T48522N
c>
8

4-Hub and Drive Plate Assembly 7-Pulley Bearing

l-Shaft Seal
5-Felt Seal Pail and Coil Housing
2-Seal Seat
GPulley Bearing Front Shield Assembly
3-Pulley

Fig. 4-Cross Section of Compressor Clutch Assembly

Litho in U.S.A.
 JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Heating and Air Conditioning 1830-7

Removal Slowly loosen the service valve mounting screw (3,

Fig. 5).

A CAUTION: High pressure may still exist at

the discharge fitting. If this pressure is re-
leased too rapidly, there may be a considerable
discharge of refrigerant and oil.

Remove the refrigerant valve from compressor. Plug

or cap openings in valve.

Cover compressor openings immediately with cover

plate to protect O-rings and prevent entry of moisture
0 :

and dirt into compressor.

Disconnect compressor clutch coil wires and re-

move the compressor drive belt.

On later units, disconnect wire from superheat 1

shut-off switch to thermal fuse.

l-Adjusting Screw 3-Service Valve Remove compressor from the mounting bracket.
2-Mounting Bolts Mounting Screw
Drain and measure oil from compressor.
Fig. 5-Compressor

If the compressor is operable, operate for 10 min-

utes by running engine at 1900 rpm with temperature
control set for maximum cooling and blower speed on
high position, before removing compressor. This
allows the refrigerant oil to be circulated in the system
and more nearly gives the correct quantity of oil in the
compressor.

1 Before Serial No. 307632, shut off engine and iso-

late the compressor from the system as instructed on
page 90-9031-l 8.

l After Serial No. 307631, the compressor cannot be

isolated from system and system must be discharged
(90-9031-13).

If the system is down due to an internal compressor

malfunction, discharge, flush and purge the system as
described in Section 90, Group 9031.

Lifho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1830-8 Heating and Air Conditioning TM- 1136 (Aw- 79)

Repair
The compressor should be tested for leaks and
internal failure before starting disassembly. Refer to
LEAK TESTING COMPRESSOR, page 18-1830-l 8.

A compressor that has an internal leak (discharge to

suction side), will require replacement or rebuilding.
External leaks can usually be corrected by installing a
new shaft seal assembly (page 18-1830-10).

Compressor Hub and Drive

Plate Assembly
Removal

l-9116 Inch Thin 2-Clutch Holding

Wall Socket Wrench

Fig. 7-Removing Lock Nut

Using the clutch holding wrench (KD-2018), hold the

clutch hub while removing the hub and drive plate lock
nut from the compressor shaft (Fig. 7).

l-JDM-16 Bench 2-Dust Cover

Holding Fixture 3-Compressor

Fig. 6-Compressor Dust Cover

Mount the compressor vertically in a JDM-16 Bench

Holding Fixture (Fig. 6) or any other suitable fixture.
Remove the three dust cover attaching screws, and
pull off dust cover.
l-Threaded Hub Puller P-Hub and Drive Plate

Fig. d-Removing Hub and Drive Plate

Using a threaded hub puller (KD-2016A) remove the

hub and drive plate assembly (Fig. 8). Remove the hub
pulling tool.

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JD 750 Crawler Bulldozer Operator’s Station 18
TM-l 136 (Nov-75) Heating and Air Conditioning--l 830-9

Align hub and drive plate assembly (with key) in

shaft. Position assembly in compressor front end
casting.

IMPORTANT: Do not drive or pound on hub of

drive plate assembly or on end of compressor
shaft. Use the proper tools to prevent possible
shifting of swash plate position (keyed to main
shaft), which might cause compressor damage.

l-Retaining Ring P-Spacer

Fig. 9-Retaining Ring and Spacer

Remove hub and drive plate retainer ring and spacer

(Fig. 9). Remove hub drive key from shaft.

Installation

Place drive key in hub drive plate. Position key so

that it will protrude about 3116 in. (4.76 mm) from
shoulder of compressor shaft when installed (Fig. 10).

l-Hub Installing Tool 2-Hub and Drive Plate

Fig. 7l-/nsfa/ling Hub and Drive Plate

Screw KD-2016B Installing Tool (Fig. 11) onto

threaded end of compressor shaft approximately 3 full
turns.

Press hub and drive plate on compressor shaft by

holding hex. end of tool with a wrench in one hand and
using a wrench in the other hand to turn the hex. nut.
Continue to press hub and drive plate until there is
0.032 in. (0.81 mm) clearance between the drive plate
and pulley. Use the 0.032 in. (0.81 mm) feeler gauge
provided as a part of Tool 2016F.

l-Compressor Shaft Shoulder 3-Key

2-Bearing Front Shield

Fig. IO-Drive Key Position

Litho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1830-10 Heatina and Air Conditionina TM- 1136 (Nov- 75)

Remove the 20168 Installation Tool. Make certain Compressor Shaft Seal
the key has remained in place by looking into drive
Removal
plate hub.
Make sure the system is depressurized before at-
i nstall hub spacer washer (Fig. 9). Secure spacer tempting to replace the shaft seal assembly. Follow
with redainer ring (flat side of ring facing spacer). instructions given in DISCHARGING THE SYSTEM,
page 90-9031-l 2.
Install a new retaining nut on compressor shaft with
the thinside of nut next to the spacer. Tighten nut to 15 Remove the hub and drive plate assembly (Fig. 8).
lb-ft (20 Nm) (2 kg) torque. Use the 2018 Clutch
Holding Wrench to hold clutch from turning while tight- Remove the pulley bearing front shield (Fig. 10).
ening nut.

Check the gap between the drive plate and pulley for
specified clearance of 0.022-0.057 in. (0.56-l .45 mm).

After compressor has been installed on crawler and

system has been evacuated and charged, cycle the
clutch off and on for at least 20 times to seat the mating
parts of the clutch. This can be done by operating
engine and turning the temperature control switch off
and on at 1 second intervals.

l-Felt Seal 2-Bearing Rear Shield

Fig. 12-Bearing Rear Shield

Carefully pry out bearing rear shield (Fig. 12) and

discard. Remove the felt seal.

IMPORTANT: Thoroughly clean inside of com-

pressor neck with compressed air before continu-
ing to disassemble.

Remove the shaft seal seat retainer ring from inside

the compressor neck.

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JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Nov-75) Heating and Air Conditioning 1830-11

Engage tabs on compressor shaft seal assembly

with locking tangs on the KD-2014B Seal Installation
and Removal Tool. Press down on tool and twist
clockwise to engage shaft seal. Remove shaft seal
assembly by pulling straight out from shaft (Fig. 14).

Remove the ceramic seal seat O-ring from the inte-

rior of the compressor neck by using the KD-2014C
O-Ring Removal Tool.

Installation :
•ZI
Be sure interior of compressor neck is clean before
reassembling parts.

l--Seal Seat Remover P-Ceramic Seal Seat

Fig. 13-Removing Shaft Seal Seat

l-O-Ring a--Washers

Fig. 75-lnsta//ing Sea/ Seat O-Ring

Coat seal seat O-ring with clean compressor oil and

place over shaft of KD2014E Tool between the two
washers. Pull O-ring tight and hold against tool (Fig.
15). insert tool into compressor neck, and push down
firmly with a jiggling motion to allow O-ring to snap into
groove.

l-Seal Removal Tool 2-Shaft Seal Assembly

Fig. 14-Removing Shaft Seal Assembly

Remove the ceramic seal seat (Fig. 13), using the

KD-2120 Removal Tool.

bitho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1830-12 Heating and Air Conditioning TM-l 136 (Nov-75)

l-Seal Installation Tool 3-Seal Shaft Assembly

P-Seal Protector

Fig. 164nstalling Sea/ Shaft Assembly

Place KD-2121 Seal Protector over end of com-

l-Driver 3-Bearing Rear Shield
pressor shaft (with thumb screw removed). Coat new 2-Installation Tool
O-ring and face of seal assembly with clean compres-
sor oil and install seal using 20148 Tool (Fig. 16). Fig. 174nstalling Bearing Rear Shield
Make sure seal is properly positioned by having the
flats of seal assembly aligned with fiats on compressor Install a new felt seal by rolling the material into a
shaft. Release 2014B Tool from seal assembly by cylinder, overlapping the ends, and placing seal in the
twisting tool slightly counterclockwise. interior of compressor neck. Carefully position seal so
that the ends butt together.
Place thumb screw in end of seal protector, and turn
screw in to remove seal protector from shaft.
With felt seal properly positioned, insert a new pulley
Coat face and outside edge of new seal seat with bearing rear shield into bore of compressor neck.
clean compressor oil, and install seal seat, using 2120 Using JDST-26-4B Installation Tool and Driver (Fig.
Tool. Make sure that seal seat O-ring is not dislodged, 17) drive shield in until it bottoms on outside end of
and that seal seat is making good contact with the neck.
O-ring.
Note that the outer face of the rear shield which
Install seal seat retainer ring with flat side against
contacts the front shield has a Teflon coating. There-
the seal seat. Place retainer ring in bore of compressor
fore, no lubricant of any kind should be used on these
neck with snap ring pliers, and complete installation by
surfaces.
using 2014D Tool to help force the retainer ring into the
groove.

Remove excess oil from inside the compressor neck

with a clean cloth.

Before installing the remaining parts, the compres-

sor should be tested for leakage of refrigerant. See
LEAK TESTING COMPRESSOR on page 18-1830-
18.

Litho in U.S.A. .
 , I

.: ‘2

JD750 Crawler Bulldozer Operator’s Station 18

TM- 1136 (Nov- 75) Heating and Air Conditioning 1830-13

l-JDST-26-4A Tool 2-Bearing Front Shield

l-OTC No. 1001 Puller P-Front Shield
Installation Tool Fig. 79-Front Shield and Installation Tool

Fig. 184nstalling Bearing Front Shield Install hub and drive plate assembly. See page
18-1830-g. Then install dust cover (Fig. 6).
Place a new bearing front shield over the pulley
bearing bore. Press in shield until it bottoms agajnst After the compressor has been completely assem-
the bearing using the JDST-26-4A Installation Tool bled, it is ready to be installed on the crawler. Evacuate
and a conventional jaw-type puller, similar to the OTC and charge refrigeration system. Perform operational
No. 1001 Puller shown in Fig. 18. test. See INSTALLATION, EVACUATION AND
CHARGING, and DIAGNOSIS AND TESTING, re-
If the front shield cocks to one side as its outer edge spectively.
starts to enter the bearing cone, lightly tap the “high”
side of the installation tool with a soft hammer to
square up the shield. Fig. 19 shows the front shield
installed.

Litho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1830-14 Heating and Air Conditioning TM-l 136 (Nov-75)

Compressor Pulley and Bearing

Removal
Remove the hub and drive plate assembly (Fig. 8).

Remove the pulley bearing front shield (Fig. 19).

Carefully pry out bearing rear shield (Fig. 12), and

discard.

Remove the pulley assembly retainer ring (Fig. 20).

Using the KD-2015 and 201X Puller Assembly as

shown in Fig. 21, remove the pulley and bearing from
the compressor neck.

Remove bearing using KD-2017A Driver.

IMPORTANT: If bearing is to be replaced, be

sure to use a John Deere bearing. This bearing has
a special seal to keep out dust and dirt.
l-Pulley Assembly

Fig. 21 -Removing PuNey and Bearing

l-Retaining Ring 2-Pulley Bearing

Fig. ZO-Pulley Bearing and Retaining Ring

Litho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM-1 136 (Nov-75) Heating and Air Conditioning 1830-15

Installation Clutch Coil and Housing

If installing the same pulley and hub-drive plate Removal
assembly, be sure to clean the contact faces of each
Remove hub and drive plate assembly (Fig. 8).
unit. Check surfaces for warpage caused by overheat-
Remove the pulley bearing shield (front and rear).
ing. Replace those parts that show evidence of war-
See Fig. 10 and 12.
page, or are badly worn.
Remove the pulley and bearing assembly (Fig. 20
and 21).

l-Felt Seal 3--Retaining Ring

P-Coil Housing
l-2017 A and B Installing Tool
Fig. 23Removing Coil Housing Felt Seal
Fig. 22-Installing Pulley and Bearing Assembly and Retaining Ring

Carefully install bearing in pulley, using KD-2017A

and B Installing Tool.
Drive pulley and bearing assembly onto compressor
neck using the KD-2017A and B Installing Tool (Fig.
22).

Check pulley for free rotation.

Install pulley snap ring retainer.

Install pulley bearing rear and front shields (Fig. 17

and 18).

Install hub and drive plate assembly. See page

18-1830-g. Then install dust cover (Fig. 6).

After the compressor has been completely assem-

bled, it is ready to be installed on crawler. Evacuate
and charge refrigeration system. Perform operational
test. See INSTALLATION, EVACUATION AND
CHARGING, and DIAGNOSIS AND TESTING, re-
spectively. l-Dowel 3-Rubber Gasket
l--Coil Housing

fig. 24Removing Co;/ Housing

Lifho in U.S.A.
7% Operator’s Station - JD750 Crawler Bulldozer
1830-16 Heating and Air Conditioning TM- 1136 (Nov-75)

Remove the felt seal and coil retaining ring (Fig. 23). CHECKING AND ADDING
A cross-sectional view of these parts installed is shown COMPRESSOR OIL
in Fig. 4.
General Information
Note position of wiring terminals on coil housing in
The compressor oil flows throughout the system with
relation to compressor body. Mark location on com-
the refrigerant when the system is operating, lubricat-
pressor body, if desired, to insure correct installation.
ing the compressor parts. In general, it is not neces-
sary to question the oil level in the system unless there
Remove coil housing assembly and rubber gasket
is evidence of a significant loss of refrigerant (hence, a
(Fig. 24).
significant loss of oil) from:

Installation
1. Broken hose
IMPORTANT: If coil is being replaced, be sure to
use 24 volt coil. 2. Severe leak at hose fitting

Check rubber gasket condition, and replace, if not in 3. Leaking compressor seals
good condition. Install gasket on compressor.
4. Collision or upset damage to system compo-
Position clutch coil on compressor head casting so nents.
the electrical terminals correspond with the mark made
previously on the compressor body. If the compressor or one of the other major system
components (condenser or evaporator) has been re-
IMPORTANT: Be sure clutch coil is correctly moved for servicing, the oil level should be checked.
seated on dowels. To check the oil level in the system, the compressor
has to be removed from the crawler. When oil is
Replace the coil retainer ring with the flat side of ring required, pour 525 viscosity oil into the oil drain tube of
facing coil. compressor.

Install felt seal next to coil retainer ring (Figs. 4 and NOTE: The compressor takes a special Frigidaire
23). 525 viscosity oil that has “‘special additives ” which give
better Frigidaire compressor life. The part number is
Install pulley and bearing assembly (Fig. 22). Then R49856; Spec. No. is UN6006 (525 viscosity).
install pulley bearing front shield (see Fig. 18 and 19).

Install hub and drive plate assembly as previously

instructed (Fig. 1 l), using the KD-2016B Installing
Tool. Do not pound or drive on the hub assembly.

bitho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Heating and Air Conditioning 1830-17

When Servicing Compressor 3. If the amount of oil drained is more than l-1/2
fluid oz. (44 mL) and the system showed no signs of a
If the air conditioning system was placed in opera-
major leak; add this same amount of new oil to the
tion just prior to removal of the compressor as de-
compressor.
scribed in REMOVAL, and the same compressor is to
be placed back on the crawler, check the oil level
4. When the amount drained is less than l-l /2 oz.
before installing. Proceed as follows:
(44 mL) and the system appears to have lost an
excessive amount of oil, add 6 fluid oz. (178 mL) of
1. Place compressor in a horizontal position with
new oil to the compressor.
the drain plug downward.

When installing a new or remanufactured compres-

2. Drain the compressor. Measure the oil in a bottle
sor that has a full charge of oil (10 fluid oz. [297 mLJ),
or container that is graduated in fluid ounces (or milli-
drain the oil and save it. Place the required amount of
l&es). Discard the oil.
oil that was saved back into the compressor in the
amount instructed in steps 3 and 4.
3. If more than 4 fluid oz. (118 mL) was drained
from the compressor, place that same amount of new
When installing a compressor that has been over-
oil back into the compressor.
hauled (and has not been filled with a full charge of oil),
add 1 extra ounce (30 mL) to the amount given in steps
4. If 4 fluid oz. (118 mL) or less was drained, add 6
3 and 4.
fluid oz. (178 mL) of new oil to the compressor.
5. Install compressor (see INSTALLATION, page
When installing a new or remanufactured compres-
18-l 830-20).
sor that has a full charge of oil (10 fluid oz. [297 mL]),
drain the oil and save it. Place the required amount of
When Servicing System Components
oil that was saved back into the compressor in the
Other Than Compressor
amount instructed in steps 3 and 4.
When replacing other system components, the
When installing a compressor that has been over- compressor will also have to be removed. Follow in-
hauled (and has not been filled with a full charge of oil), structions given above for checking compressor oil and
add 1 extra ounce (30 mL) to the amount given in steps add the following amounts of oil for each listed com-
3 and 4. ponent being serviced:
Evaporator-4 fluid oz. (118 mL)
IMPORTANT: Do not add any more oil than Condenser-2 fluid oz. (59 mL)
necessary, or maximum cooling will be reduced.
IMPORTANT: If complete system was flushed to
5. Install compressor (see INSTALLATION, page remove contamination, the full charge of oil (11
18-1830-20). fluid oz. [326 mL]) should be added to the system.

If the air conditioning system was not placed in

operation (or the compressor was not operable just
prior to removal), and the same compressor is to be
placed back on crawler, check the oil level before
installing. Proceed as follows:

1. Place compressor in a horizontal position with

the drain plug downward.

2. Drain the compressor. Measure the oil in a bottle

or container that is graduated in fluid ounces (or milli-
litres). Discard the oil.

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18 Operator’s Station JD750 Crawler Bulldozer
1830-18 Heating and Air Conditioning TM-1 136 (Apr-79)

LEAK TESTING COMPRESSOR Mount the compressor in a vise with the oil reservoir
A compressor that has been removed from the unit up.
should be tested for internal and external refrigerant
Remove the dust cover (2, Fig. 6).
leakage before making repairs on compressor. See
REPAIR, page 18-1830-8.
Rotate the clutch hub by hand. If it can be rotated,
proceed with the test, if it cannot be rotated, replace
Perform the following Volumetric Efficiency Test to
the compressor.
determine if the compressor is serviceable. If the
compressor fails the volumetric efficiency test, it must
install D-18032KD test plate (3, Fig. 25).
be replaced.

Connect the low side valve (1, Fig. 25) to the left
Volumetric Efficiency Test
hand test plate fitting and the high side valve (2) to the
right hand fitting.

The center hose must be left “open” to the atmo-

sphere. Refer to Fig. 25.

NOTE: The low pressure gauge hose is connected

to the discharge adapter so that the pressure reading
during the test, can be more easily read.

Close the low side valve and open the high side
valve. Refer to Fig. 25.

T65292N

l-Low Side Valve 2-High Side Valve (Open)

(Closed) 3-Test Plate (D-18032KD)

Fig. 25-Volumetric Efficiency Test Hook-Up

IMPORTANT: There must be a minimum of one

ounce (30 mL) of oil in the compressor to perform
this test. If all the compressor oil was lost during
Discharging The System, pour a minimum of one
ounce (30 mL) of oil into the compressor reservoir.

bitho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Heating and Air Conditioning 1830-19

Shaft Seal Leak Test

T43797N

T65293N l-Low Pressure Gauge 3-lest Plate (D-18032KD)

Valve (Open) 4-Refrigerant Con-
l-Speed Handle P-Clutch Hub 2-High Pressure Gauge tainer
Valve (Closed)
Fig. 26-Volumetric Efficiency Test
Fig. 27-Testing for External Leaks
With the dust cover removed, use a speed handle
(1, Fig. 26) to rotate the compressor clutch hub ten
revolutions at a rate of one revolution per second. 1. Install D-18032KD Test Plate on rear head of 1
compressor (Fig. 27).
Refer to Fig. 26.
If the low side valve (left hand) gauge registers 60 2. Connect pressure gauges and hoses to test
psi (4 bar) or more, the compressor is serviceable. plate. Both gauge valves should be closed.
Perform the Shaft Seal Leak Test.
3. Connect the yellow hose to center outlet on
If the gauge registers less than 60 psi (4 bar), the
compressor is not serviceable and must be replaced. pressure gauge manifold, and to a refrigerant supply
container.
NOTE: A gauge reading below 60 psi (4 bar) means
one or more suction and/or discharge valves are 4. Open refrigerant container valve and LOW pres-
.
leaking or there is an internal leak. sure gauge valve. Charge compressor to container
pressure (container at room temperature).
After performing the volumetric efficiency test, re-
lease the air pressure from the high side. Remove oil
5. Test area around shaft seal assembly for leaks
drain plug and drain oil from compressor. Let oil drain
using D-05232ST Electronic Leak Detector. If a leak is 1
for ten minutes. Add proper amount of oil as directed in
detected, try turning the compressor shaft a few turns.
CHECKING AND ADDING COMPRESSOR OIL, page
Again, test for leaks. If a leak persists, it may be
1830-16.
necessary to remove the shaft seal assembly, and
determine the cause for the leak.

6. Close the low pressure gauge valve, and the

refrigerant container valve. Slowly disconnect the yel-
low hose from the refrigerant container. Cover con-
nection with a cloth to protect yourself from escaping
refrigerant.

Litho in U.S.A.
 18 Operator’s Station JD750 Crawler Bulldozer
1830-20 Heating and Air Conditioning TM- 1136 (Apr- 79)

7. Slowly open gauge valves to discharge the re- Installation

frigerant from compressor.
Before installing compressor, be sure the compres-
sor contains the correct amount of oil. See the infor-
8. Remove pressure gauges, hoses, and
mation given in CHECKING AND ADDING COM-
1 D18032KD Test Plate.
PRESSOR OIL, page 18-1830-16.

9. Install cover plate on compressor to keep out

IMPORTANT: Compressors kept on hand for
moisture and contamination.
stock purposes should be charged with refriger-
ant, whenever the refrigerant charge is lost. Keep

q
Discharge to Suction Side
compressor openings capped until installation, to
: Leak Test
prevent moisture and foreign material from enter-
ing compressor.

NOTE: Before installing compressor, rotate the

compressor shaft 4 or 5 times. This permits proper
lubrication of compressor seal over all its surface. Be
sure to remove all excess oil from the outside surface
of the compressor to prevent oil being thrown onto the
magnetic clutch.

Install compressor on crawler and connect the

magnetic clutch control wiring.

On later units, also connect wire lead from thermal 1

fuse to superheat shut-off switch.
l’43797N

l-Low Pressure Gauge 3-Test Plate (D-18032KD)

Install compressor drive belt and tighten to 0.25 in.
Valve (Closed) 4-Refrigerant Con- (6.35 mm) deflection with a 15 Ibs. (67 N) (7 kg) force.
2-High Pressure Gauge tainer
Valve (Open) IMPORTANT: New compressors are charged
with a mixture of nitrogen, Refrigerant-12, and 10
I Fig. B-Testing for Internal Leaks
fluid oz. (297 mL) of Frigidaire 525 viscosity oil. If
the cover plate is removed too rapidly, oil will be
1. Follow steps 1, 2 and 3 as given under “Shaft
blown out with the sudden release of pressure.
I Seal Leak Test.” Refer to Fig. 28.
When installing an exchange or rebuilt compressor,
2. Open container valve and HIGH pressure gauge
SLOWLY remove the cover plate from the compressor
valve. Charge compressor to container pressure. If
port at the rear head of the compressor to bleed off any
pressure is immediately observed on the low pressure
pressure that may exist in the compressor.
gauge, it indicates there is an internal leak. Replace
the compressor.

3. Close the high pressure gauge valve. Slowly

disconnect the yellow hose from the refrigerant con-
tainer. Cover connection with a cloth to protect yourself
from escaping refrigerant.

4. Follow steps 7, 8 and 9 as given under “Shaft

Seal Leak Test.”

Litho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Heating and Air Conditioning 1830-21

Coat the compressor manifold O-ring packings with 2. Install gauges to service valve connectors and
compressor oil and install refrigerant valve on com- purge air from hoses.
pressor. Tighten cap screw (3, Fig. 5) to 35 lb-ft (47
Nm) (5 kg-m) torque. 3. Mid-position service valves.

IMPORTANT: Prevent dirt or moisture from en- 4. Conduct operational test.

tering the compressor manifold assembly. Gauge
port caps should be in place. If the complete system was discharged for service,
refer to EVACUATING THE SYSTEM, page 90-9031-
Be sure to flush the complete system if com- 13.
pressor failed internally due to broken parts or
seizure. Refer to FLUSHING THE SYSTEM, page
go-9031 -19.

If ONLY the compressor was discharged and

opened up for service, use the following procedure:

1. Purge air from compressor by cracking low side

service valve for three seconds with low side hose
connector capped and high side hose connector open.

Litho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1830-22 Heating and Air Conditioning TM- 1136 (Apr- 79)

THERMAL FUSE AND SUPERHEAT

SHUT-OFF SWITCH

General Information Removal

The purpose of the superheat switch located on the To remove the superheat switch from the rear head
rear of the compressor is to stop compressor action of the compressor, remove pressure from the system
when the refrigerant level in the system is low. This as explained under “Isolating Compressor From Sys-
prevents possible damage to the compressor from a tem.”
lack of lubrication.
Remove snap ring on superheat switch and pull
The switch senses refrigerant pressure and tem- switch and O-ring from compressor.
perature at the suction inlet to the compressor.
To remove thermal fuse, disconnect harness from
The thermal fuse, located on the back of the com- fuse and remove hardware attaching fuse to compres-
pressor bracket, contains a heat sensitive fuse and sor bracket.
heater element. If a combination of low pressure and
high temperature occurs in the suction inlet of the hepair
compressor, the superheat switch closes. Current in
The superheat shut-off switch or thermal fuse can-
the thermal fuse is then routed through a heater ele-
not be repaired. Test as shown in Group 9015 and
ment in the thermal fuse to ground. The heat melts the
replace if defective.
“fuse” and electrical power is removed from the com-
pressor.
Installation
The thermal fuse has a built-in time delay. Follow removal procedure in reverse order.

Litho in U.S.A.
 JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Heating and Air Conditionino 1830-23

CONDENSER, RECEIVER-DRYER, AND EVAPORATOR

CONDENSER ( -307631) CONDENSER (307632- )
General Information General Information
The condenser is mounted directly in front of the
radiator. Air is drawn through the condenser by the
engine fan, permitting heat exchange to take place.

Be sure that the condenser core is not plugged with

dirt or trash, or excessive heat and pressure may build :
up, causing system to not function properly. •II
Removal
Depressurize the refrigeration system as instructed
1 in DISCHARGING THE SYSTEM, page 90-9031-13.

,,., ., ,~
l-Condenser Fan Motors 3-Power Lead
a-condenser 4-Ground Lead

Fig. 30-Condenser Location I

The condenser and condenser fans, located in the

right cab side panel, function is to change the hot
refrigerant gas back to its cooler liquid state.

Air is drawn in through the condenser core by the

condenser fan, permitting heat exchange to take place.

Be sure that the condenser core is not plugged with

dirt or trash, or excessive heat and pressure may
result, causing system to not function properly.

Removal
Discharge the system as described in DISCHARG-
ING THE SYSTEM, page 90-9031-13. I
Remove fan support leaving fans attached.

Disconnect inlet and outlet openings. Cap all open-

l-Mount Screws 2-Inlet and Outlet Hoses ings and remove condenser from mounting structure
I Fig. 29-Removing Condenser by removing four cap screws.

Disconnect inlet and outlet hoses, and remove con- Drain oil from condenser and discard. Plug or cap
denser from mounting track by removing cap screws condenser and hose fittings.
I (Fig. 29).

Drain oil from condenser and discard. Plug or cap

condenser and hose fittings.

Litho in U.S.A.
 18 Operator’s Station JD750 Crawler Bulldozer
1830-24 Heating and Air Conditioning TM- 1136 (Apr- 79)

Repair Installation
Remove the plugs or caps from openings. If con- Flush and purge the core. Refer to page 9031-19. 1
tamination is evident in condenser, flush all compo-
I nents (page 90-9031-l 9). Reverse the removal steps. Use the torque chart
(Group 1899, this section) as a guide for tightening
Examine condenser core for possible restrictions or connections on pipes and hoses.
sources of trouble. The fins should be straight and free
of dirt or trash. NOTE: If the condenser was repaired or replaced

q:
, with a new one, pour 2 fluid oz. (59 mL) of oil into
Check condenser core for leaks. Cap the outlet condenser. If there were any major leaks in the system,
connection and install a Schrader type service valve in refer to CHECKING AND ADDING COMPRESSOR
the inlet opening. Place refrigerant container in a pail of OIL, (page 18- 1830- 76).
water heated to a maximum of 125°F (52°C) which
gives a pressure of 167.5 psi (12 bar) (12 kg/cm2). Evacuate and charge the system.
Connect refrigerant supply to the Schrader valve.
Open refrigerant container valve and test condenser Perform the operational test.
for leaks with a leak detector (see LEAK TESTING). If
the aluminum condenser core leaks, repair or replace
with a new one. Plug or cap openings until ready to
install.

RECEIVER-DRYER
General Information The receiver-dryer has a two-fold function. First, it
receives the high-pressure liquid refrigerant from the
condenser and stores the liquid until needed by the
evaporator. Second, the unit removes harmful mois-
ture (and acids), and filters out solid contaminants.

Solid contaminants are filtered by the strainer-filter

pads, while moisture and acids are removed by the
desiccant material filling the chamber between the filter
pads (Fig. 31). I

The sight glass is incorporated into the outlet side of

the receiver-dryer unit and should be used for checking
system operation.

Replace the receiver-dryer whenever the air condi-

T43799N n tioning system has been discharged or when it cannot
absorb further moisture. Diagnosis of moisture in the
l-Desiccant 4-Pick-up Tube system is difficult. Therefore, if all checks are “NOR-
2-Sight Glass 6-Filter Pad
MAL” and the operator complains of lack of cooling
~-TO Expansion Valve 6-Front Condenser
below 80°F (27°C) there probably is moisture in the
I Fig. 3 7-Cross Section of Receiver-Dryer system and the receiver-dryer should be replaced.

Litho in U.S.A.
 JD750 Crawler Bulldozer Operator’s Station 18
TM- I 136 (Apr- 79) Heating and Air Conditioning 1830-25

Removal Installation
Reverse the removal procedure for installing unit.

Refer to torque chart in Group 1899 for tightening

refrigerant pipes.

IMPORTANT: Replace receiver-dryer as often

as required to prevent moisture from contaminat-
ing the system. Always install a new receiver-dryer
whenever the system is opened up for service, or
whenever the compressor shaft seal leaks. Be sure
to keep new receiver-dryers capped until ready to
install. Install receiver-dryer last.

l--Inlet Fitting 4-Outlet Fitting

Evacuate and charge system (page 90-9031-13). 1
2-Receiver-Dryer 5--Sight Glass
3-Clamp Perform operational test (page 90-9031-l 1). I

I Fig. 3%Receiver-Dryer Removal ( -30763 1)

I After Serial No. 307632, the receiver-dryer is locat-

ed to the left of the condenser fans.

Depressurize the system as instructed in DIS-

I CHARGING THE SYSTEM, page 90-9031-13.

Disconnect the inlet and outlet fittings on receiver-

I dryer (Fig. 32).

Remove the receiver-dryer clamp and remove as-

sembly. Cap or plug openings.

Repair
The receiver-dryer assembly is not repairable.

To service a malfunctioning unit, replace with a new

one.

IMPORTANT: Whenever a major air condition-

ing component is opened up for service, a new
receiver-dryer should be installed.

IMPORTANT: Always install other system com-

ponents before installing a new receiver-dryer.
This will help keep the receiver-dryer from ab-
sorbing additional moisture prior to evacuation.
Keep caps on receiver-dryer until just before the
lines are to be connected.

Litho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1830-26 Heating and Air Conditioning TM- 1136 (Apr- 79)

EVAPORATOR
General information IMPORTANT: The tube connecting the bulb to
the expansion valve contains a low pressure gas.
The evaporator is constructed of aluminum and
To avoid improper valve action, do not kink or
greatly resembles an ordinary cooling system radiator.
pinch the tube, or dent the bulb.
Refrigerant travels through tubes located within the
core. The heater core mounting bolts may have to be
removed and the heater swung out of the way to
To obtain maximum cooling efficiency, the refriger- remove evaporator.
ant must remain in the evaporator for a sufficient length
Remove evaporator core mounting screws, and lift
of time to completely vaporize. Too little or too much
out core. Note the amount of oil that drains from the
refrigerant entering the evaporator will limit refrigerant
core. Cap openings.
capacity to absorb heat. The regulatory controls for the
evaporator are the expansion valve and the thermo-
Repair
static temperature control switch.
If contamination is evident in system, flush and
Removal purge entire system (page 90-9031-l 9). I
Accessible minor leaks may be repaired, but the
evaporator should be replaced if there is a restriction or
a major leak in the core. The core should be tested with
at least 50 psi (3 bar) (4 kg/cm2) when testing for leaks.

Installation
Flush and purge core. Refer to page 9031-19.

Inspect drain hoses for cracking, splitting, or any

other form of deterioration. Replace as required. After
307631, inspect dump valve on drain hoses.

Remove caps from evaporator core openings and

l--Outside Filter 3-Evaporator reverse the removal instructions. Be sure to thoroughly
2-Thermostat Control 4-Paper Filter
wrap expansion valve, sensing bulb, and adjoining
Sensing Tube
section of the inlet refrigerant pipe with insulation tape
fig. 33-Evaporator to get desired expansion valve control.

Use care when tightening parts. Refer to the torque

Depressurize the system as explained in DIS- chart in Group 1899 when necessary.
CHARGING THE SYSTEM, page 90-9031-13.
NOTE: If the evaporator was repaired or replaced
Remove the right and left control console covers. with a new one, pour 4 fluid oz. (118 mL) of refrigerant
oil into the evaporator. If there were any major leaks in
Remove the climate control cover at the rear of the the system, refer to CHECKING AND ADDING COM-
operator’s station. PRESSOR OIL (page 18- 1830- 16).
Install new receiver-dryer.

A CAUTION:
refrigerant.
bines may still contain some
Observe ail precautions as de- Evacuate and charge system (page 90-9031-13).
scribed on page 9031-12. Perform the operational test (page 90-9031-11). 1

Disconnect sensing bulb, evaporator inlet and outlet

fittings and expansion valve equalizer line fitting.

IMPORTANT: Cap all lines and fittings to prevent

entry of moisture or contaminants.

Remove sensing tube from evaporator core.

Litho in U.S.A.
 JD750 Crawler Bulldozer Opera for’s Station 18
TM- 1136 (Apr-79) Heating and Air Conditioning 1830-27

REGULATORY CONTROLS
EXPANSION VALVE

General Information Disconnect sensing bulb, expansion valve inlet and

outlet fittings, and equalizer line fittings.
Liquid refrigerant under high pressure is piped to the
expansion valve from the receiver-dryer. The function
IMPORTANT: Plug or cap openings after remov-
of the expansion valve is to regulate the amount of
inrr valve and bulb. :*

q
liquid refrigerant entering the evaporator (now under
low pressure), depending upon the heat load on the
IMPORTANT: lf valve seems to have been :
evaporator. Sensing action which regulates valve ac-
operating properly, be careful not to kink or pinch
tion takes place in the temperature sensing bulb.
the tube connecting the sensing bulb to the valve
body when removing the unit.
The expansion valve has an external equalizer
which allows pressure at the valve outlet (or evaporator /’
Repair
inlet) to be transmitted to the evaporator side of the
diaphragm. Since there are no external adjustments, an im-
properly working expansion valve must be replaced by
Removal a new one.

Installation
Before installing valve, remove the caps from open-
ings and check screen in valve inlet for foreign materi-
al. If foreign material is present, remove the screen and
clean. Do not allow contamination to enter valve. Re-
verse the removal steps.

There must be good contact between the evaporator

tail pipe and the full length of the sensing bulb.

Thoroughly wrap insulation tape around valve,

sensing bulb, and adjacent portion of refrigerant pipe to
get desired expansion valve control.

Be careful not to lift the sensing bulb from the

evaporator tail pipe when wrapping with tape.

NOTE: If there were any major leaks within the

l-Outside 6-Equalizer Line
system, it will be necessary to remove the compressor,
2-Evaporator 6-Expansion Valve drain the oil and add the correct amount of oil as
3-Heater Core 7-High Pressure Switch instructed on page 18- 1830- 17.
4-Temperature Sensing &Receiver-Dryer Outlet
Bulb Line
g-suction Line

Fig. 34-Expansion Valve ( -307631 shown)

I

Depressurize the system as instructed in DIS-

CHARGING THE SYSTEM, page 90-9031-12.

Remove climate control cover.

Remove the insulation from sensing bulb and ex-

pansion valve.

Litho in U.S.A.
 18 Operator’s Station JD750 Crawler Bulldozer
1830-28 Heating and Air Conditioning TM- 1136 (Apr- 79)

THERMOSTATIC TEMPERATURE CONTROL SWITCH

2’43802N

l-Temperature Control Switch 2--Sensing Tube

I Fig. 35Temperature Contfo/ Switch

General Information Turning the control knob all the way to the left
(counterclockwise) manually opens the contact points
The purpose of the temperature control switch (Fig.
in the switch housing, stopping compressor operation.
1 35) is to regulate the temperature of the refrigerant in
the evaporator corresponding to the control knob set-
Removal
ting selected by the operator.
Turn off battery disconnect switch.
The switch consists of a set of contact points which
receives its power from the pressurizer motor switch.
Remove climate control cover.
The current flows from the temperature switch to the
compressor clutch/condenser motors relay.
Remove sensing tube from evaporator core (Fig.
The contact points in the temperature switch are 33). I
controlled by a gas-filled temperature sensing tube
having a spring bellows or diaphragm on one end Remove the left control console cover and remove
making contact with the point operating mechanism. switch from cover.
The other end of the sensing tube is inserted into the
core of the evaporator. Disconnect wiring and remove switch.

When the control knob is turned on (clockwise), the

Note the routing and shaping of the sensing tube so
contact points close, thereby activating the compres-
that it can be reinstalled and shaped the same way as
sor. However, the compressor will not operate unless
removed.
the pressurizer motors are turned on. As the tempera-
ture in the evaporator reaches its specified lower limit,
the contact points are allowed to open, which in turn
shuts off the compressor. The compressor will remain
off until the temperature in the evaporator reaches its
specified upper limit. When that limit is reached, the
contact points close and the compressor starts
operating. In this manner, the compressor turns off and
on automatically to satisfy the demands of the eva-
porator.

Litho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Am-79) Heating and Air Conditionina 1830-29

Repair Installation
The temperature control switch is not designed to be Route and shape the sensing tube the same as
repaired as such. However, it should be tested for removal.
proper operation. To test the switch, place the end of
the sensing tube in a cup or similar container filled with Insert the temperature control switch sensing tube
a mixture of ice and water. insert a thermometer into into the evaporator core from the rear of the core.
the water. Observe the contact point operation based
upon the temperature of the liquid. The switch should When the sensing tube is correctly installed, it will
open and close within the range of 29” to 38°F (-2” to enter the rear center (side to side, top to bottom) of the
-3°C). If the switch does not operate properly replace core and its end will be flush with the front surface of
with a new one. the core.

Switches are preset to correctly regulate the tem- Insert the tube in the evaporator core.
perature in the evaporator.
IMPORTANT: Do not pinch or kink the sensing
tube. If necessary to reshape tube to fit into core,
avoid making too sharp a bend.

Install switch into console cover.

COMPRESSOR RELIEF VALVE

General Information Repair

The compressor relief valve (22, Fig. 3) is a pressure The valve is not designed to be repaired. If the valve
regulating control. If the system discharge pressure does not operate properly or has been damaged, re-
exceeds 440 psi (30 bar) (31 kg/cm2), the valve will place with a new one.
open automatically and stay open until the pressure
recedes. The valve discharges to the atmosphere and Before replacing valve, make sure that there is not a
will then close automatically when pressure drops malfunction somewhere else in the system.
below its setting.
Installation
If the relief valve opens, a loud popping noise will be
Install valve on compressor.
heard. In addition, some oil may be ejected through the
valve. Correct any condition that would cause this
Add refrigerant as required (page 90-9031-14).
valve to open.
Perform operational test (page 90-9031-9).
Removal
Prior to 307632, isolate the compressor from the unit
as instructed on page 90-9031-l 8 or discharge system
(90-9031-13).

After 307632, discharge system (90-9031-l 3).

Slowly remove the valve from compressor in case

some high pressure still remains.

Litho in U.S.A.
 18 Operator’s Station JD750 Crawler Bulldozer
1830-30 Heating and Air Conditioning TM- 1136 (Apr- 79)

REFRIGERANT COUPLINGS ( -307631)

Pi’38033

l-Tubing Adapter S-Gasket Seal S-O-Ring

2-O-Ring 6-Lock Nut g-Valve and Sleeve
3-Poppet Valve Assembly 7-Union Nut and Assembly
4-Body Body Assembly W-O-Ring
1 l-Tubing Adapter
I Fig. 36-Exploded View of Refrigerant Coupling

General Information Disassembly

The refrigerant coupling (Fig. 36) is used on both the To remove the male coupling half, remove the lock
pressure and return sides of the air conditioning sys- nut (6) which fastens the coupling to the mounting
tem, and is located under the floor panel in front of the bracket on the cab. Unscrew tt,e body (4) with poppet
left control console cover. valve assembly (3) from the adapter (1) and remove
O-ring (2).
1 After 307631, the couplings are no longer used.
To remove the female coupling half, unscrew the
When the coupling is disconnected, both halves seal
union nut and body assembly (7) from the adapter (11).
to prevent loss of refrigerant and admission of air or
Remove O-ring (10).
foreign material into the system.
As the two coupling halves are partially connected Repair
I together by the union nut (7, Fig. 36), the stem valve
If coupling leaks, replace the coupling half (male or
head of the valve and sleeve assembly (9) contacts the
female, or both) and O-rings (2) and (10). Valve as-
face of the poppet valve assembly (3) expelling air.
semblies (3) and (9) are not serviced separately from
Body (4) contacts a gasket on the face of sleeve (9)
bodies. However, seal (5) is serviced separately.
making a seal during the connection.

Tightening the union nut (7) draws the coupling Assembly

halves together. At the same time, the poppet valve
Install O-rings on both adapters. Lubricate O-rings
assembly (3) and valve and sleeve assembly (9) are
with compressor oil (525 viscosity) to prevent them
moved to open the fluid passage around the valves.
from scuffing or tearing when coupling body is thread-
When fully coupled, gasket seal (5) on the recessed
ed on adapter.
face of the body (4) is compressed between faces of
coupling bodies (4) and (7) to form a seal. During Insert poppet valve assembly (3) into body (4).
disconnection, the springs automatically return valves Tighten body on adapter (1) until there is metal-to-
(3) and (9) to their sealing position. metal contact, and then tighten body an additional l/8
in. (3.18 mm).
NOTE: Tubing adapters (1) and (1 I) are brazed to
their respective pipes, and therefore are serviced only Lubricate O-ring (8) liberally with compressor oil and
as an assembly. insert valve and sleeve assembly (9) into body (7).
Tighten body on adapter (11) until there is metal-to-
metal contact, and then tighten body an additional l/8
in. (3.18 mm).

_ Litho in U.S.A.
 JD 750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Heating and Air Conditioning 1830-31

HIGH TEMPERATURE SWITCH (307632- )

GENERAL INFORMATION INSTALLATION
The high temperature switch located on the evapo- The switch is not repairable, and when found de-
rator to receiver-dryer line senses the temperature of fective, must be replaced with a new one.
the line. If the condenser becomes plugged, the line
becomes hot. The high temperature switch cuts off Before replacing switch, make sure the condenser
power to the condenser fans and compressor and housing cover and condenser core are free from dirt
switches power to the plugged condenser indicator so and trash. A build-up of dirt or trash around the con-
the light will come on. denser will cause higher refrigerant operating temper-
atures that may be high enough to cause the high
temperature switch to open.
q
’

Also, check condenser fan motors to be certain both

of the motors are operating at rated speed (2800 to
3200 rpm).

l-High Temperature 3-Yellow Lead to Air

Switch Conditioning Relay
P-Brown Lead to 4-Black Lead to
Plugged Condenser Thermostat
Light

I Fig. 37-High Temperature Switch

REMOVAL
Disconnect and tag switch leads.

Remove clamp from switch.

Remove switch.

Litho in U.S.A.
ia Operator‘s Station JD750 Crawler Bulldozer
1830.32 Heating and Air Conditioning TM- 1136 (Apr- 79)

AIR INTAKE SYSTEM

PRESSURIZER BLOWERS AND SWITCH

T43804N

I-Nut (8 used) 4-Cab Blower Harness 7-Blower Motor Switch Knob

2-Left Air Duct Housing 8-Blower Motor Switch &-Right Air Duct Housing
3-Left Blower Assembly GSwitch Mounting Bracket g-Right Blower Assembly

Fig. 38-Blower Motors

General Information Removal

The pressurizer blower motors draw fresh air Remove the left or right control console cover.
through the outside filter and recirculate cab air
through the filter located under the climate control Remove the air duct mounting bolts and pull duct up
cover. with blower motor attached.

The pressurizer blowers have to be in operation Disconnect wiring to motor and remove motor from
before the air conditioning system will function. Gen- air duct.
erally speaking, the blowers should be in operation
most of the time, not only to direct cooled or heated air To remove blower motor switch, remove left control
into the cab, but to prevent dirt or dust from entering console cover, disconnect wiring and attaching hard-
around panels and doors, by pressurizing the inside ware and remove switch.
air.

Litho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Heating and Air Conditioning 1830-33

Repair AIR FILTERS

The blower motors and switch are not repairable. If Refer to the crawler operator’s manual for air filter
the motor or switch fail to perform satisfactorily, the service instructions.
part should be replaced.

Test as part of the electrical system in Section 90,

Group 9015.

Installation
Place assembly in position to reverse removal steps.

Litho in U.S.A.
18 Operator’s Station JD750 Crawler Bulldozer
1830-34 Heating and Air Conditioning TM- I 136 (Apr- 79)

Litho in U.S.A.
JD750 Crawler Bulldozer Operator’s Station 18
TM- 1136 (Apr- 79) Specifications and Special Tools 1899-1

Group 1899
SPECIFICATIONS AND SPECIAL TOOLS
COMFORT AND CONVENIENCE ITEMS
SPECIFICATIONS AND TORQUE VALUES

Cigar Lighter ..... . . . . . . . . . . . . . . 12 volt

:
OPERATORENCLOSURE m I*
SPECIFICATIONS AND TORQUE VALUES

1 - ROPS-to-cab
cap screws . . . . ... . . . . . . . . . . 350 lb-ft
(475 Nm) (48 kg-m)

Fig. 1-ROPS-to-Cab Attaching Cap Screws

1 - l/2” x l-1/4”
cap screws torque . . . . 120 lb-ft
(163 Nm) (17 kg-m) I
2 - 3/4” x 2-3/4” cap screws torque 425 + 43 lb-ft
(576 k 56 Nm) (59 -c 6 kg-m)
3 - 7/8” x 2” cap screws torque . . . ,685 r 68 lb-ft
(929 + 92 Nm) (95 lr. 7 kg-m)
4 - 3/4” x 2-l/2” cap screws torque 425 ? 43 lb-ft
(576 t 58 Nm) (59 t 6 kg-m)

T62353N

Fig. PROPS Cap Screws Torque

Litho in U.S.A.
 18 Operator’s Station JD750 Crawler Bulldozer
1899-2 Specifications and Special Tools TM- 1136 (Apr- 79)

INSTRUMENTS AND INDICATORS

SPECIFICATIONS AND TORQUE VALUES

Mechanical Instruments and Indicators

Transmission Oil Pressure Gauge

Gauge operating range . . . . . . .O to 300 psi
(0 to 21 bar) (0 to 21 kg/cm2)

:
IIP Normal operating range . . 130 to
(9 to 21 bar) (9 to 21
300 psi
kg/cm*)

Transmission Oil Temperature Gauge

Gauge operating range . . . . . . . . . 0 to 250°F
/
(-18 to 121°C)
Normal operating range . . . . . . . . . . . 0 to 200°F
(-18 to 93°C)

Engine Water Temperature Gauge

Gauge operating range . . . . . 100 to 300°F
(38 to 149°C)
Normal operating range . . . . . . . . . . . 160 to 224°F
(71 to 107°C)

Engine Oil Pressure Gauge

Gauge operating range .. . . . . . 0 to 80 psi
(0 to 6 bar) (0 to 6 kg/cm*)
Normal operating range . . . . . . . . . .25 to 80 psi
(2 to 6 bar) (2 to 6 kg/cm*)

Electrical Instruments and Indicators

Voltmeter
Gauge operating range . . . . . . . . . 20 to 32 volts

Equipment Hydraulic Oil Filter Light

Will light with pressure
differential of . . . . . . . . . . . . . . . . . 40 psi
(3 bar) (3 kg/cm*)

Transmission Oil Filter Light

With light at. . . . . . . . . . . . . . . . . 5 psi vacuum
(169 mbar)

Indicator Light Bulb Replacement Chart

indicator Light Color Bulb Trade No.

Equipment Hydraulic Filter Red 456

Transmission Oil Filter Red 456

Litbo in U.S.A.
JD750 Cm wler Bulldozer Operator’s Station 18
TM- 1136 (Nov-78) Specifications and Special Tools 1899-3

EXTERNAL ENGINE SPEED CONTROL

SPECIFICATIONS AND TORQUE VALUES

1 - Speed Control Head Set Screw . 225 + 25 lb-in

(25 -+ 2.8 Nm) (2.6 2 0.29 kg-m)

T44829N

Fig. 3-Speed Control Head Set Screw

Litho in U.S.A.
 -
18 Operator’s Station JD 760 Crawler Bulldozer
1899-4 Specifications and Special Tools TM-1 136 (Nov-78)

AIR CONDITIONING SYSTEM

SPECIFICATIONS AND TORQUE VALUES
Compressor-High Pressure Relief Valve
Willopenat ./ . . . . . . . . . . . . . .._......... 440psi
(30 bar) (31 kg/cm2)

1 - Compressor drive plate lock

nut torque.. . . . . . . ~. . . . . . . . . . . . . 15 lb-ft
(20 Nm) (2 kg-m)
2 _ Gap between drive plate and
pulley . . . . . . . . . . . . . . . . . 0.022 - 0.057 in.
(0.56 - 1.45 mm)

I Fig. 4-Compressor Drive P/a/k Installation

Compressor Oil . . . . . . . . . . . . . . . . . . . 525 viscosity

Amount to be added when
replacing components
Compressor (new or
rebuilt) . . . . . . __. . . . . _. _. . 11 fluid oz. (326 ml)
Evaporator . . . . . . . . . . . . . 4 fluid oz. (118 ml)
Condenser . . . . . _. . . . . . . . . . 2 fluid oz. (59 ml)

1 - dompressor drive belt tension . . . . . . l/4 in.

(6.35 mm)
with 15 lb. (67 N) (7 kg) force

2 - Refrigerant valve cap screw

torque.. . . . . . . . . _. . . _. . . . . . . . . 35 lb-ft
(47 Nm) (5 kg-m)

Fig, S-Compressor lnsfallafion

Litho in U.S.A.
JD 750 Crawler Bulldozer Operator’s Station 18 I
TM- 1136 (Mar-78) Specifications and Special Tools 18994

AIR CONDITIONING SYSTEM

SPECIFICATIONS AND TORQUE VALUES-Continued

Hose and Tubing O-Ring Connection Torques

Metal Tube Thread and

Outside Diameter Fitting Size Torque”
inches (mm) inches (mm) lb-ft (Nm) (kg-m)

l/4 (6.35)
3/8 (9.53)
l/2 (12.7)
7116 (11.11)
518 (15.88)
3/4 (19.05)
lo-15 (14-20) (l-2)
lo-15 (14-20) (l-2)
24-29 (33-39) (3-4)
:
m
518 (15.88) 7/8 (22.22) 26-31 (35-42) (4)
314 (19.05) l-1/16 (26.99) 30-35 (41-47) (4-5)

*Dip O-ring in refrigerant oil prior to assembly and tightening.

Lifho in U.S.A.
 18 Operator’s Station JD750 Crawler Bulldozer
1899-6 Specifications and Special Tools TM- 1136 (Mar-78)

AIR CONDITIONING SYSTEM

SPECIAL TOOLS

Convenience Tools

Tool Tool Number Use

Manifold Pressure Gauge Set 2051-I Testing system pressures

Safety Goggles - 2054t Prot&ting eyes
Leak Detector JDST-22 Detecting refrigerant leaks
Air Conditioning Wrench 2046t Adjusting service valves
Pocket Thermometer 2055t Measuring outlet air temperature
-: 2056t Using pressurized refrigerant cans
-_ ’ Refrigerant Can Dispensing Valve
Universal Refrigerant Can Dispenser 2088 Using pressurized refrigerant cans
Portable Vacuum Pump JDST-26-3 Evacuating system
Seal Kit 2014tt Remove and replace compressor seal
and O-rings
Universal Pulley Puller 2015-f-t Removing compressor pulley
Universal Clutch Service Kit 2016’rt Remove and install clutch hub
Universal Bearing Service Set 2017tt Remove and install pulley bearing
Clutch Holding Wrench 2018tt Removing hub and drive plate
Snap Ring Pliers 2020tt Removing retainer rings
Test Plate 2050 Testing compressor for leaks
Seal Seat Remover 2120tt Removing ceramic seal seat
Seal Sleeve Protector 2121 tt Installing compressor shaft seal
Expansion Valve Screen Remover 2122tt Removing expansion valve screen
Shield Installation Tool JDST-26-4A Installing front (rotating) portion
of pulley bearing front shield
Shield Installation Tool JDST-26-4B Installing rear (stationary) portion
of pulley bearing front shield

?Air Conditioner Test Equipment Set No. JDST-26-l

ffAirConditioner Compressor Service Tool Kit No.
JDST-26-2

Litho in U.S.A.
JD 750 Crawler Bulldozer Sheet Metal and Styling 19
TM- 1136 (Nov-75) Hood or Enaine Enclosures 1910-l

Section 19
SHEET METAL AND STYLING
CONTENTS OF THIS SECTION

Page Page
GROUP 1910 - HOOD OR ENGINE ENCLOSURES GROUP 1921 - GRILLE AND GRILLE
Hood HOUSING
General Information .. . . . . . . 191 O-3 General Information . ..... ... . 1921-l :-- :
Removal .. . . . . . . . . . . . 191 O-3 Removal . . . . .... ... 1921-l ‘!:
Repair . ..... . . . . ... . 191 O-3 Repair ..... . ..... . . .. .. 1921-2 ‘-
Installation. . . . . . . . 191 O-3 Installation . . . . . . . . ... .. . .
Cowl
General Information . . . . 191 O-5
Removal . . 1910-5
Repair . 19104
Engine Side Shields
General Information . 1910-6
Removal . . . . . 1910-6
Repair 1910-6
Installation. . 1910-6
Brush Shield
General Information .. 1910-7
Removal .. . 1910-7
Repair .. . 1910-7
Installation. . .. . .. 1910-7

Litho in U.S.A.
19 Sheet Metal and Styling JD750 Crawler Bulldozer
1910-2 Hood or Engine Enclosures TM--i 136 (Nov- 75)

Litho in U.S.A.
JD750 Crawler Bulldozer ShZGt Metal and Styling 19
TM-1 136 (Nov-75) Hood or Ermine Enclosures 1910-3

Group 1910
HOOD OR ENGINE ENCLOSURES
HOOD
GENERAL INFORMATION REPAIR
The hood is of one piece design and can be re- Reference Fig. 2 for parts. Check condition of the
moved without removing the engine side shields. locks (12) and replace as necessary.

REMOVAL INSTALLATION
Reverse removal procedure.

Fig. l-Hood Removed

Remove pre-cleaner and muffler extension.

Release locks holding front of hood.

Remove hardware holding rear of hood and remove

hood.

Litho in U.S.A.
19 Sheet Metal and Styling JD750 Crawler Bulldozer
1910-4 Hood or Engine Enclosures TM-l 136 (Nov-75)

l-Support &Nut (4 used) 15-Cap Screw (4 used)

2-Lock Washer (4 used) 9-Washer (4 used) %-Rubber Bumper
3-Cap Screw (9 used) lo-Anchor (2 used) 17-Rubber Bumper
4-Latch Knob 11-Pin (2 used) Is-Spring Pin
5-Spring 12-Lock (2 used) 19-Cover Latch
S-Hood 13-Cotter Pin (2 used) 20-Washer (5 used)
7-Holddown (2 used) 14-Lock Washer (4 used)

Fig, P-Hood

Litho in U.S.A.
JD750 Crawler Bulldozer Sheet Metal and Styling 19
TM-l 136 (Feb-77) Hood or Engine Enclosures 19104

COWL
GENERAL INFORMATION REPAIR
The cowl is used to support the instrument panel. Check cowl for cracks or other damage and repair or
replace as necessary.
REMOVAL
Turn battery disconnect to “OFF” position. INSTALLATION
Reverse the removal procedure.
Remove platform for access to electrical connectors
which are placed on splitter housing. Disconnect the
connectors.

Remove instrument panel.

Remove hood (see page 19-1910-3).

Remove cowl.

l-Vandal Cover Retainer 2-cowl

(2 used with lever steering, 3-Lock Washer (6 used)
1 used with pedal steering) 4-Gap Screw (6 used)

Fig. ~-COW/

Litho in U.S.A.
19 Sheet Metal and Styling JD750 Crawler Bulldozer
1910-6 Hood or Engine Enclosures TM- 1136 (Feb-77)

-.._ ENGINE SIDE SHIELDS

GENERAL INFOdMATlON REPAIR
Engine side shields are used to protect the engine The engine side shields are of steel construction. If
and components located in the engine compartment damaged, they may be straightened to their original
from damage. shape.

REMOVAL Repair or replace the side shields as needed by their

condition.
Remove attaching hardware to remove the engine
side shields along with the brush shields.
INSTALLATION
install engine side shields in reverse order of re-
moval.

@-1

l-Cap Screw (6 used) 3-Right Engine Shield

2-Washer (6 used) 4-Left Engine Shield

Fig. 4-Engine Side Shields

Litho in U.S.A.
JD750 Crawler Bulldozer Sheet Metal and Styling 19
TM- 1136 (Feb-77) Hood or Engine Enclosures 1910-7

BRUSH SHIELD

GENERAL INFORMATION REPAIR

The brush shields along with the engine side shields The brush shields are of steel construction. If dam-
are used to protect the engine compartment. The aged, they may be straightened to their original shape.
hole-filled design also lets air pass freely.
Repair or replace the brush shields as needed by
REMOVAL their condition.

Remove the brush shield along with the engine side

INSTALLATION
shield.
Fasten brush shields to engine side shields and
install on crawler.

RIdHT ENGINE SHIELD

T'48606N

l-Nut (3 used) 4-Gap Screw (5 used)

2-Bracket 5-Washer (3 used)
3-Lock Washer (2 used) S-Brush Shield

Fig. 5-Brush Shield

Litho in U.S.A.
19 Sheet Metal and Styling JB750 Crawler Bulldozer
1910-8 tiood or Enaine Enclosures TM- 1136 (Feb-771

Litho in U.S.A.
JO750 Crawler Bulldozer Sheet Metal and Styling 19
TM- 1136 (Nov-781 Grille and Grille Housim 1921-l

Group 1921
GRILLE AND GRILLE HOUSING
GENERAL INFORMATION Remove hose cover from grille and remove grille.
The grille and grille housing are designed to protect
engine, radiator and engine components. The grille
housing is also used to support the bulldozer blade lift
cylinders support.

Fig. P-Disconnecting Hydraulic Hoses

Disconnect and cover end of hydraulic hoses (Fig.

2).

Remove top grille housing (1, Fig. 1).

Remove grille housing (3) using a minimum capacity

l-Top Grille Housing 3-Grille Housing
O-Grille
l-ton (900 kg) hoist.

Fig. I-Grille and Grille Housing

REMOVAL
Remove pre-cleaner and exhaust stack.

Remove brush shields, engine side shields and

hood.

Litho in U.S.A.
19 Sheet Metal and Styling JD750 Crawler Bulldozer
1921-2 Grille and Grille Housing TM- 1136 (NOW78)

REPAIR

l-Latch Knob S-Washer (4 used) il-Cap Screw (8 used)

2-Spring Pin 7-Gap Screw (4 used) 12-Nut (12 used)
3-Spring 8-Grille Housing l&-Special Washer (12 used)
4-Cover Latch g-Grille 14-Gap Screw (12 used)
~-TOP Grille Housing lO-Special Washer (8 used)

Fig. 3-Grille and Grille Housing

See Fig. 3 for parts. INSTALLATION

Use a minimum capacity l-ton (900 kg) hoist to
Be sure grille housing is in good condition, as it does
position grille housing on crawler.
support the bulldozer blade lift cylinders.

Torque cap screws (14, Fig. 3) as follows:

On units ( -273375) ... ... 500 lb-ft

(678 Nm) (69 kg-m)
On units (273376- ) ... . . . . . 685 lb-ft
(929 Nm) (95 kg-m)

When fastening hydraulic hoses, be sure hose ends

and fittings are clean.

Litho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (Mar-78) Blade 3201-l

Section 32
DOZER
---I--s.-- A- -...- --a-.-..

CUNTENTS WI- THIS StC; I IUN

Page Page

GROUP 3201 - BLADE GROUP 3260 - DOZER HYDRAULICS

Geheral Information .................... 3201-3 Dozer Pump
Removal .............................. 3201-3 General Information .............. 3260-l
Repair ................................ 3201-4 Removal ........................ 3260-2 _
:i
Installation ............................. 3201-5 Repair .......................... 3260-3 ;.:
installation. ...................... . 3260-5 ;:
GROUP 3215 - CONTROLS LINKAGE Reservoir and Filters
Removal .............................. 3215-l General Information .............. . 3260-6
Repair ................................ 3215-2 Removal ........................ . 3260-6
Adjustment ............................ 3215-2 Repair .......................... 3260-7
installation ............................. 3215-2 Control Valve
General Information .............. 3260-8
GROUP 3242 - SUB FRAME Removal ........................ 3260-l 2
Removal .............................. 3242-l Repair .......................... 3260-l 2
Repair ................................ 3242-2 Installation. ...................... 3260-l 5
Installation ............................. 3242-2 Cylinders
General Information .............. 3260-l 6
GROUP 3243 - MOVABLE FRAMES Removal ........................ 3260-l 6
General information .................... 3243-l Repair .......................... 3260-17 1

q
Removal .............................. 3243-l Installation. .. . . .. . . . . 3260-24 (
Repair ................................ 3243-2
Installation. ............................ 3243-2 GROUP 3299 - SPECIFICATIONS AND
SPECIAL TOOLS
Specifications and Torque Valves
Dozer Hydraulics. . . . . . . 3299-l
Movable Frame . . . . . . . .. . 3299-l
Special Tools
Dozer Hydraulics. . . .. 3299-4

Lifho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3201-2 Blade TM- 1136 (Mar-78)

Litho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (Feb-77) Blade 3201-3

Group 3201
BLADE
GENERAL INFORMATION The JD750/6520 angle bulldozer has blade with
adjustable dozing angle. Pitch jacks or hydraulic cylin-
The JD75016525 hydraulic tilt, straight bulldozer has
ders (optional) adjust blade dozing angle (see Fig. 2).
a hydraulic tilt cylinder (4, Fig. 1) on right of blade and
an adjustable pitch jack on left of blade. Hydraulic tilt
cylinder allows operator to adjust blade tilt angle from
seat. Manually adjustable pitch jack adjusts blade tilt-
angle range.

l-Hose Shield 5-Strut-to-C-Frame Pin

P-Cylinder-to-Blade Pin and Bracket
3-Strut-to-Blade Pin 6-GFrame Trunnion Pivot
4-Cylinder-To-Strut Pin ‘I-Lift Cylinder-to-C-Frame
Trunnion Pivot

Fig. P-Angle Bulldozer Blade (Hydraulic)

l-Cap Screw (8 used) 4-Lift Cylinder Rod

P-Hose Clamp Mounting Ball
3-Strut 5-Pin (2 used)

Fig. l-Straight Bulldozer Blade

REMOVAL

6525 Straight Bulldozer: Attach hoist to both sides of blade.

Lower blade to ground. Operate blade control levers

Remove 8 cap screws holding struts to blade. Note
back and forth to relieve hydraulic pressure.
number of shims for reassembly.

Remove 4 cap screws holding tilt cylinder rod to

Remove 2 cap screws holding lift cylinder rods to
blade. Note number of shims for reassembly.
cylinder mounting ball (4).

Remove 4 cap screws holding pitch screw jack to

Remove cap screw running through pin (5) and
blade. Note number of shims for reassembly.
blade boss. Drive out pins.

Remove hose clamp (2) from blade by removing 2

Lift blade with hoist and remove from crawler.
cap screws.

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3201-4 Blade TM- 1136 (Feb- 77)

6520 Angle Bulldozer: REPAIR

Lower blade to ground. Move blade control levers
back and forth to relieve hydraulic pressure.

l-Cylinder Mounting Ball 7-Right-Hand Cupped End

(2 used) Bit
2-Blade &Right-Hand End Bit
3-Left-Hand End Bit 9-Nut (2 used)
4-Left-Hand Cupped End lo--Pin (2 used)
T48830i'
Bit 11-Nut (27 used)
5-Cutting Edge 12-Lock Washer (27 used)
l-C-Frame 4-Blade Pivot Pin
6-Bolt (27 used) 13-Gap Screw (2 used)
2-Cellar 5-Back of Blade
14-Strut Socket
3-0.35 In. (9 mm) Gap

Fig. 4-Straight Bulldozer Blade Assembly

Fig. 3-Blade-To-C-Frame Middle Pivot Area

Refer to Fig. 4 for straight bulldozer blade assembly.

Remove cap screws holding hose shield (1, Fig. 2)
to blade. Remove hose shield. Separate hoses and
Inspect all parts for wear, cracks, or other damage.
coupling block from blade.
The blade cutting edge is reversible. Turn cutting edge
over to renew cutting surface.
Remove cap screws and pins (2) holding cylinders
or pitch jacks to blade.
When blade is not used, coat all polished surfaces
with grease to prevent rust.
Attach hoist to both sides of blade.

Remove cap screws and pins (3) holding struts to

blade.

Remove cap screw running through collar (2, Fig. 3)

and pivot pin (4). Slide collar off pin.

Raise blade slightly with hoist. Move blade away

from crawler to separate blade from C-frame.

Lifho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (Apr- 79) Blade 3201-5

INSTALLATION

6525 Straight Bulldozer:

Attach hoist to both ends of blade. Position blade
ahead of crawler. Align pivot pin holes (4, Fig. 1) in side
of blade with holes in push beam.

Install pins (10, Fig. 4) and retaining cap screws

(13). Tighten cap screw nut (9).

Position lift cylinder rods on cylinder mounting balls

(1, Fig. 4). Put cap on other side of mounting ball and
install 2 cap screws without shims. Measure gap be-
tween cylinder rod end and cap. Add shims to fill gap.
Add one thin shim for clearance between cylinder rod
end and cap. Install cap and 2 cap screws. If cylinder
rod does not reach mounting ball, start engine and
extend cylinder rod slowly until end of rod contacts
mounting ball.

Place shims (7, 8, 9 and 10, Fig. 5) on end of strut

(5). Add shims to fill the gap between the strut (5) and
blade. Align strut with holes on back of blade. install
cap screws (12) holding struts to blade but do not
tighten.

Measure the distance from the pushbeam to track

frame on both sides. This will determine if the blade is
centered. If the blade is not centered, remove a shim
from the excess shimmed strut. Add that shim to the
side with a gap between the strut and blade. Tighten
strut cap screws (12).

Assemble socket (1) to pitch jack (4) joint without

shims. Measure gap between socket and pitch jack.
Add shims (2 and 3) to fill gap. Add one thin shim for
clearance between socket and pitch jack. Align holes in
l--Socket 7-Shim (use as required)
pitch jack with holes in blade. Install 4 mounting cap 2-Shim (use as required) &Shim (use as required)
screws. 3-Shim (use as required) g--Shim (use as required)
4-Pitch Jack W-Shim (use as required)
Place shims on end of tilt cylinder rod. Align holes in 5-Strut (2 used) Ii-Cap Screw (4 used)
GStrut Socket (2 used) 12-Cap Screw (8 used)
cylinder rod end with holes in blade. Install 4 cap
screws. Fig. 5Straight Bulldozer Shims

Install hose clamp on blade.

Remove hoist from blade.

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3201-6 Blade TM- 1136 (Apr- 79)

6520 Angie Bulldozer: 6. Struts have pitch jacks in blade-end of strut. Strut
is screwed in or out to align strut-to-C-frame pin with
Attach hoist to both sides of blade. Align blade pivot
hole in bracket (5).
pin (4, Fig. 3) with hole in C-frame. Move blade back
and guide blade pivot pin (4) through hole. Slide collar
7. Lift strut and check pin-to-C-frame bracket
(2) on pin and install retaining cap screw.
alignment. If strut pin does not align with hole, adjust
length of strut. Place bar through strut bracket (4, Fig.
IMPORTANT: Note following steps to adjust
2). Screw strut in or out using bar until strut pin and
angle bulldozer blade. There must be 0.35 in. (9
C-frame bracket (5) align.
mm) gap (3, Fig. 3) between head of pin and C-
frame when blade is installed.
8. Install strut pins in C-frame brackets. Install re-
taining cap screws and lock nuts.
1. With blade pivot pin installed, move blade for-
ward.
9. Make sure 0.35 in. (9 mm) gap (3, Fig. 3) exists
when both struts are installed.
2. Make sure gap (3) is at least 0.35 in. (9 mm).

Lift hydraulic cylinders or pitch jacks into position on

3. Remove hydraulic cylinder pins (4, Fig. 2) or pitch
struts. Install pins (4, Fig. 2) and retaining cap screws.
jack pins. Remove cylinders or pitch jacks from struts.
Set cylinders or pitch jacks on ground. It is not neces-
Align blade-end of cylinders or pitch jacks with
sary to disconnect cylinder hoses.
brackets (2) on blade. Install pins and retaining cap
screws.
4. Remove strut-to-c-frame pins (5, Fig. 2). Sepa-
rate struts from C-frame.
Attach hoses and coupling block to blade. Install
hose shield (1).
5. Attach struts to blade with pins (3) and retaining
cap screws.

Litho in U.S.A.
JD750 Crawler Bulldozer Dozers 32
TM- 1136 (A pr- 79) Controls Linkage 3215-l

Group 3215
CONTROLS LINKAGE
REMOVAL

T64035F LEVER

l-Knob l&-Lock Washer (2 used) 19-Lock Washer (2 used)

2-Control Lever 11-Special Nut (2 used) P&-Cap Screw (2 used)
3-Base 12-Bushing (2 used) Pl-Groove Pin
4-Ball Joint (3 used) 13-Tilt Lever Rod 22-Lock Washer
6-Nut (6 used) M-Lock Washer 23-Linkage Rod
6-Ball Joint (3 used) l&Ball Joint 24-Cap Screw
7-Litt Lever Rod 16Nut (2 used) 26-Base
8-Cap Screw (2 used) 17-Nut (2 used) 26Cap Screw
g-Latch 1 &Bracket

Fig. l-Dozer Control Lever

On units without cab remove outside right panel Remove rear fender on right side.
from equipment control box.
Remove belly pan. This will allow removal of work on
On units with cab remove right console cover. the entire linkage. If a specific portion of the linkage is
to be worked on only remove as much as needed to
Remove floor plate. work or remove that specific part.

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3215-2 Controls Linkage TM- 1136 (Apr- 79)

6-Cap Screw g-Tilt Lever

l-Groove Pin (4 used)
2-Lever (2 used) 6-Lock Washer (2 used) lo-Lift Lever
7-Control Shaft Bracket 1 l-Cap Screw
3-Lift Shaft
4-Tilt Shaft 6-Bushing (6 used)

Fig. 2-Two-Spool Control Shaft Bracket

REPAIR ADJUSTMENT
Inspect control valve linkage for worn or damaged The centerline of holes on control function lever (9
parts and replace as necessary. and 10, Fig. 2) should be parallel to the ground.

NOTE: Thoroughly coat the inside surfaces of The portion of the control lever (2, Fig. 1) as it comes
bushings (8, Fig. 2) with John Deere Never Seez or an from the control lever base (3, Fig. 1) and before it 1
equivalent prior to installing the control shafts. bends should be eyed so that it is coming straight up in
all directions.

INSTALLATION
Reverse repair and removal procedure and reinstall.
JD750 Cm wler Bulldozer
Dozer 32
TM- 1136 (Nov-75) Controls Linkage 3215-3

LI?T CONTROL
LEVER

p.,.---, 1-2 ,- h
(,CONTROL VALVE
L 2,' “,I-’ I

XIW.“,
CT!!!5
T43180

I-Cap Screw 4-Lift Lever Rod 7-Lock Washer (2 used)

P-Rod End Ball Joint S-Cap Screw B-Nut (2 used)
3-Nut (2 used) B-Spacer

Fig. 3-Lift Control Valve Rod

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
32154 Controls Linkage TM- 1136 (Nov- 75)

. 1

T43087

l-Cap Screw (2 used) 4-Lever Rod

2-Rod End Ball Joint !5-Lock Washer
3-Nut (2 used) 6-Nut (2 used)

Fig. 4-Tilt Control Rod

Litho in U.S.A.
JD 750 Crawler Bulldozer Dozer 32
TM- 1136 (Nov-75) Sub Frame 3242-1

Group 3242
SUB FRAME

_-e-.

_ .-.
-:..I

l-support 7-Yoke Cap (2 used) 13-Special Washer (10 used)

2-Grease Fitting (2 used) &Washer (4 used) 14-Gap Screw (4 used)
3-Bushing (2 used) g-Cap Screw (4 used) Xi-Lock Washer (4 used)
4-Bushing (2 used) lO-Grease Fitting (4 used) %-Hood Bracket (2 used)
5-Oil Seal (2 used) 11-Bushing (4 used) l7-Retainer (2 used)
6-Yoke (2 used) 12-Gap Screw (10 used)

Fig. l-Sub Frame

REMOVAL Remove upper radiator hose and radiator bracket.

Remove brush shields, engine side shields, hood

Disconnect horn wire and move out of way.
and grille top housing.
The yokes (6) may be removed with the support
Remove lift cylinders as directed in Section 32,
(1).
Group 3260.
Connect hoist to support.
NOTE: Tag yoke caps (7, Fig. I) for installation.
They are machined to the yoke ‘and should be rein- Remove cap screws (12) and washers (13) and re-
stalled to the same yoke. move support.

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3242-2 Sub Frame TM- 1136 (Nov-75)

REPAIR INSTALLATION
Refer to Fig. 1 for assembly and disassembly. Follow removal procedure in reverse order.

To remove yokes, remove cap screws, lock wash-

ers and hood bracket (14, 15 and 16, Fig. 1). The re-
tainer (17) is threaded to accept cap screw for
removal. Inspect all parts and replace as necessary.

Lifho in iJ.S;A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (A pr- 79) Movable Frame 3243-i

Group 3243 ’
MOVABLE FRAME

T62215N

lo--Bolt (4 used) I9-Strut Socket (2 used)

1 -Pitch Jack Pivot (2 used)
11-Nut (4 used) PO-Shim (use as required)
2 -Left Push Beam
12-Gap Screw PI-Shim (use as required)
3 -Bushing (2 used)
13-Pin (2 used) 22-Grease Fitting (2 used)
4 -Trunnion (2 used)
4A-Trunnion (used with 14-Special Nut (4 used) 23-Socket
132 in. (335 Cm1 blade only) i5--Cap Screw (2 used) 24-Shim (use as required)
16-Pivot Pin (2 used) 2%Shim (use as required)
5 -Special Washer (12 used)
6 -Cap Screw (12 used) i7-Strut (2 used) 26Cap Screw (8 used)
7 -Shim (use as required) 18-~ap Screw (8 used) 27--Pitch Jack
8 -Shim (use as required) P&-Jack Pivot Yoke
9 -Trunnion Pivot Cap (2 used)
Fig. l-Push Beam

GENERAL INFORMATION Disconnect and plug tilt cylinder hydraulic lines and
disconnect hose clamp.
The JD750 Crawler Bulldozer has a hydraulic, tilt
blade with a mechanically adjustable pitch jack on Attach a chain hoist to rear of frame.
the left side of the push beam.
Remove attaching hardware and raise frame from
REMOVAL crawler.
Lower blade to ground and operate dozer control
lever to relieve hydraulic pressure. Back crawler away from the dozer assembly. Low-
er rear of dozer assembly to the ground.
Disconnect lift cylinders at the blade.
Remove blade as directed in Section 32, Group
Attach lift cylinders to the tapped boss on the grille 3201 (if necessary).
housing with the straps stored on the side of the hy-
draulic cylinders.

Litho in U.S.A.
32 Dozer JD750 Crawler Bul/doz%
3243-2 Movable Frame TM- 1136 (ADr- 79)

REPAIR INSTALLATION
Follow removal procedure in reverse order.
A CAUTION: To avoid possible injury, and
insure best results, always stop crawler
Refer to Section 32, Group 3201 for shimming of
operation and lower or block up frame and blade
strut and pitch jack to blade if blade was removed.
before servicing dozer units.

Assemble trunnion pivot (2, Fig. 1) and trunnion

Refer to Fig. 1 for assembly and disassembly.
pivot cap (9) to trunnion (4) without shims. Measure
gap between trunnion pivot and trunnion pivot cap. Add
inspect pins and bushings for excessive wear and
shims (7 and 8) to fill gap.
replace as necessary.

Note number of shims (20 and 21, Fig. 1) for reas-

sembly.

When assembling pitch jack, be sure ball of pitch

jack seats into socket firmly and add one extra shim to
aid in adjustment of pitch jack.

If the pitch jack pivots (1, Fig. 1) are to be replaced,

installing the tilt cylinder or pitch jack may aid in align-
ing pivot to push beam.

Grease all fittings before resuming operation.

l-Shim (use as required) 4-Trunnion

2-Shim (use as required) !%Bolt (4 used)
3-Shim (use as required)

Fig. 2-Shim /nsta//ation

Add extra shims (2, Fig. 2) as necessary to prevent

trunnion pivot cap from binding on trunnion (4).

Torque trunnion pivot cap bolts (5) to 300 lb-ft (407

Nm) (42 kg-m).

Litho in U.S.A.
JD750 Crawler Bulldozer Dozers 32
TM- 1136 (Apr- 79) Dozer Hydraulics 3260-l

Group 3260
DOZER HYDRAULICS
DOZER PUMP
GENERAL INFORMATION

l--Outlet Body S-Drive Shaft g--Vane

IL-Pressure Plate GWiper 1O-Ring
3-Shaft Bearing 7-Rotor 1 l-Wear Plate
4-Shaft Seal &Insert 124nlet Cover

Fig. l-Dozer Pump

( -266925 shown)

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3260-2 Dozer Hydraulics TM- 1136 (Apr- 79)

The dozer hydraulic pump is of the balanced, sin- The cartridge is composed principally of a pressure
gle-cartridge, intra-vane design with the pump inlet plate, ring, rotor, vanes, inserts, and wear plate. The
port located in the cover and the outlet port located rotor is driven within the cartridge by a drive shaft
in the body. Principal pump parts are: (1) body, (2) coupled to the transmission accessory drive shaft. As
cover, (3) pump cartridge, and (4) drive shaft and rotor speed increases, centrifugal force causes the
bearings. vanes to follow the cam-shaped contour of the ring,
providing the necessary pumping action. System
Inlet flow of oil from the reservoir is ported through pressure, fed behind the vanes and inserts, assures
the cover to the pump cartridge. The cartridge then sealing contact of the vanes on the ring cam contour
discharges the oil through porting in the pressure during operation.
plate and pump body to the hydraulic system (Fig.
2). Vane Action
The intra-vane design (Fig. 2) provides a means of
Cartridge Operation controlling the outward thrust of the vanes on the
cartridge ring at different positions of vane travel
around the ring. Full system pressure is continuously
applied through the rotor intra-vane passages for this
outward vane thrust. This force is applied only over
the area between the vane and insert (10,. Fig. 2).
Because this area is small, thrust is correspondingly
light.

During vane travel through the pressure quadrants,

full system pressure is also applied against the bot-
tom area of the vane. The valving of pressure to and
from the bottom area of the vanes is through holes
drilled in the rotor (8, Fig. 2). This selective applica-
tion of pressure keeps the vane in constant radial hy-
draulic’balance in all quadrants of the cartridge ring.

‘* REMOVAL
Before removing hydraulic pump, release pressure
in reservoir and hydraulic system.

Drain reservoir >and disconnect pump inlet and out-

let lines. Remove pump from splitter housing.

l-High Pressure Oil 6-Vane

(Outlet) ‘I-Drive Shaft
~-LOW Pressure Oil &Drilled Holes in
(Inlet) Rotor
3-Outlet g-Insert
4-Rotor lO-Force Between Vane
5-Inlet and Insert
1 l-Rotation

Fig. P-Hydraulic Pump Oil Flow

Lifho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (Apr- 79) Dozer Hydraulics 3260-3

REPAIR

l-Shaft GBearing 11-Sealing Ring

2-Washer ?-Retaining Ring 12-O-Ring
&Seal I-Retaining Ring 13-Pump Cartridge ( -266925)
&Seal g--Back-Up Ring Pump Cartridge (266926- )
!&Body lo-O-Ring 14-Cover
16-Cover Bolt (4 used)

fig. 3-Exploded View of Dozer Hydraulic Pump

Remove four cover bolts (15) and cover (14, Fig. 3). Pump Cartridge
Note position of cover inlet port with reference to body
Remove O-rings and backup rings from hub and
outlet port before removal so that the cover may be
outside diameter of pressure plate.
returned to its original position during reassembly.
NOTE: Disassembly of the pump cartridge is not
Turn pump cartridge slightly and at the same time
recommended. The pump cartridge has no internal
pull it outward and remove cartridge from drive shaft.
service parts. Replace cartridge if tests determine it is
The pump cartridge may be loosened by prying under
faulty.
the flats of the ring with two screwdrivers. Lay the
cartridge aside on a clean smooth surface for disas-
sembly and inspection. Remove larger O-ring from
recess in body.

Litho in U.S.A.
 32 Dozer JD750 Crawler Bulldozer
3260-4 Dozer Hvdraulics TM- 1136 (Apr- 79)

Pump Shaft Position shaft bearing in place on drive shaft, being

careful not to cock the bearing. Press bearing against
Remove bearing-retaining ring and shaft snap ring
shoulder of shaft. Lubricate the chamfered edge of the
from inside of body. Remove drive shaft and bearing
shaft. With tape around end of shaft to protect seal,
from bd,dy by gently tapping the splined end of shaft
install shaft and bearing into body until bearing is fully
with a soft-tipped hammer.
seated. If necessary, gently tap the shaft with a plastic
headed hammer. Install shaft snap ring and bearing
1 Check bearing (6, Fig. 3) for wear before removing it
retaining ring, making certain both parts are firmly
from the shaft.
seated in place.

inspect drive shaft at the point of contact with bush-

Also be sure that both bearing retaining ring and
ing and sealing lip of shaft oil seal. If excessive scoring
shaft snap ring are installed in the groove nearest the
or wear is noted, replace shaft.
bearing in order to locate shaft in its proper place in
pump body.
1 Remove washer (2) from bore in body. Pull shaft oil
seal and felt seal from body.
Pump Cartridge
Dip all parts in clean hydraulic oil to facilitate as- Install O-ring and backup ring in groove on hub
sembly and provide initial lubrication. diameter of pressure plate. Install a backup ring and
O-ring around large step of pressure plate. Make cer-
Pump Shaft tain that smooth sides of backup rings face the sealing
rings.
Install a new felt seal and oil seal in counterbore of
body. Soak both seals thoroughly in hydraulic oil be-
~ Position large O-ring in recess in body.
fore installation. Make certain that lipped edge of seal
is toward inside of body.

l-Left-Hand (Counterclockwise) 3-Ring

Rotation 4-Shaft End
P-Rotor

Fig. 4-Direction of Rotor Rotation

I -266925 Shown)

Lifbo in U.S.A.
JD75Q Crawler Bulldozer Dozer 32
TM- 1136 (Apr- 79) Dozer Hydraulics 3260-5

Install pump cartridge on drive shaft and seat it firmly If cover is not located on pins, inlet will be
in place in body. restricted. Pump delivery will be low and pump will
cavitate.
Install cover making certain that the two locating
pins fit into the holes inside the cover. Seat cover firmly After the unit has been completely reassembled,
and secure in place with four cap screws. Oil the pour a small quantity of clean hydraulic oil into the
threads of the cap screws and tighten to 90 lb-ft (122 cover inlet port. Rotate drive shaft several turns by
Nm) (12 kg-m). hand to check for free rotation and to assure complete
lubrication of the cartridge parts.

If pump is not reinstalled on unit, cap pump inlet and

outlet ports to prevent entrance of foreign materials
into the cover or body.

INSTALLATION
Grease splined end of pump shaft with John Deere
Never-See2 Lubricant or an equivalent before install-
ing the pump.

Install pump on unit and connect lines. Be sure both

clamps on suction line contact pump.

Tighten pump to splitter housing cap screws to 170

+ 17 lb-ft (230 -c 23 Nm) (24 ? 2 kg-m).

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3260-6 Dozer Hydraulics TM- 1136 (Apr- 79)

RESERVOIR AND FILTERS

GENERAL INFORMATION
The hydraulic reservoir is the sump area for the A pressure switch is also mounted on the filter
equipment hydraulic system and is pressurized to housing head and will turn on a warning light on the
keep out dirt and to hold pressure for positive flow to instrument panel just before the filter relief valve
the pump. opens to indicate that the filter needs service.

A filter relief valve is located in the filter housing

head which allows return oil to bypass the filter and
enter the reservoir.

REMOVAL

i5 117,,U3

26'
25

l-Cap Screw (3 used) 1 l--Plug lg-Washer (6 used)

a-Washer (3 used) 12-O-Ring 20-Screw (6 used)
3-Gap Screw (4 used) 13-O-Ring (2 used) 21-Plug
4-Washer (3 used) 14-Reservoir Window 22-O-Ring
5-Gap Screw (18 used) 16-Reservoir Window 23-O-Ring
6-Lock Washer (18 used) Retainer 24-Plug
7-Cover 16-Washer (4 used) 26-Special Self-Tapping
&Gasket Cover 17-Screw (4 used) Screw
g--Shim l&-Side Cover 26-Hydraulic Sump
l&--Shim

Fig. 5-Reservoir

Litho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM-1 136 (Nov-78) Dozer Hydraulics 3260-7

A CAUTION: The hydraulic reservoir is pres-

surized. Slowly remove the fill plug to re-
lieve resevoir pressure.

Generally the reservoir need not be removed for

service unless replacement is necessary.

The fuel tank must be removed in order to remove

the reservoir.

REPAIR
Replace the return filter at the service periods in
the operator’s manual. Also replace return filter when
major service work is performed on the dozer func-
tions hydraulic components.

Inspect filters and associated parts for wear. Test

filter springs tension.

Refer to Fig. 6 during disassembly and assembly

of the supplementary filter.

l-Cap Screw (8 used) 7-Plug

a--Lock Washer (8 used) 8-Lock Washer (4 used)
3-O-Ring g--Cap Screw (4 used)
4-Pressure Switch lo-Filter Element
5-Hydraulic Filter 11-Oil Filter
Adapter 12-Return Tube
8-O-Ring 13-Seal

Fig. 6-Hydraulic Sump Filter

Litho in U.S.A.
32 Dozer JD-is0 Crawler Bulldozer
3260-8 Dozer Hydraulics TM-l 136 (Nov-78)

CONTROL VALVE
GENERAL INFORMATION

l-Plate, Left End &-Lift Section Valve g-Relief Valve

Z-O-Ring (2 used) flilt Section Valve IO-Backup Washer
3-O-Ring 7-R.H. Port Plate 1 l-O-Ring
&O-Ring &O-Ring

Fig. 7-Control Valve Assembly

The dozer hydraulic functions control valve is an A detent in the lift valve spool end cap retains the
open-center, two-spool, stack-type valve. spool in the float position. The section also contains
two circuit relief valves and an anti-cavitation check
Valve Construction valve.

The lift and tilt work sections are separate bodies

containing single spools. All sections have lift checks
which serve as one-way valves to prevent the blade
from dropping during engagement of a spool into a
power position.

Litho in U.S.A.
 JD 750 Crawler f3ulldozer Dozer 32
TM- 1136 (Nov-78) Dozer Hydraulics 3260-g

Valve Porting The system relief valve is a pilot operated relief

valve (Fig. 8). Leakage with this type of relief valve is
The port plate for the lift valve contains a non-ad-
very small as pressures approach the relief setting.
justable pilot-operated relief valve which serves as the
system relief.
These valves are not field adjustable and any at-
tempt to adjust the valves will damage them.
Valve Oil Flow in Neutral
Oil from the pump enters the port plate. Direct-Acting Type

With both valve spools in the neutral position, oil is

free to flow through the valve and return to the reser-
voir. Intermediate pressure is maintained at the valve
inlet by the internal restriction of the oil passing through
the valve and on to the reservoir. All valve work ports
are blocked in this position.

Relief Valves
Pilot Operated Type
w- 6

6 T
/
-1
--- 2

T32877N

l-Pressure Oil 4-Seat

2-Return Oil S-Retainer
3-Shims 6-steel Ball

Fig. 9-Cutaway of a Direct-Acting Type

Relief Valve

---+2
!l’32876N Circuit relief valves in the lift valve sections provide
relief when high pressure is created by some force
l-Pressure Oil +-Poppet other than the pump. This force could be caused by the
2-Return Oil Cifice
3-Pilot Body 7-Filter Screen blade suddenly striking a hidden object. Circuit relief
4-Seat valves in the lift section are of the direct-acting type.

Fig. d-cutaway of a Pilot-Operated Type

Relief Valve

/ Litbo in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3260-l 0 Dozer Hydraulics TM-l 136 (Nov-78)

CONTROL VALVE OIL FLOWS

Blade Lift Section

T48583N -3

i-Pressure Oil 4-Anti-Cavitation Check Valve 7-Control Valve Spool

2-Return Oil 5-Lift Check Valve &Outlet Ports
3-Trapped Oil GCircuit Relief Valve 9-Detent Mechanism

Fig. lo-Blade Lift Section

Blade Lift Power Circuit Blade Lift Float Circuit

When the blade spool is moved into a power posi- When the blade lift valve spool is in the float position,
Con, the spool blocks pressure oil flow through valve to the detent in the spool cap engages the valve spool.
the reservoir and redirects oil through the lift check The spool will be held in this position until manually
valve, around spool, and then to cylinder end. Return released.
oil from cylinder flows around spool to reservoir
through cavities inside the valve. With the blade lift spool in the float position, both
cylinder ports are open to the outlet port in the valve.
Thus, the blade floats up and down, following the
ground contour. The cylinder pistons freely move back
and forth.

Litho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM-l 136 (Nov-78) Dozer Hydraulics 3260-11

Tilt Power Circuit LIFT CHECK VALVE

When the tilt spool is moved into a power position, Each section of this valve body is equipped with a lift
the spool blocks pressure oil flow through valve to the check valve.
reservoir and redirects oil through the lift check valve,
around spool, and then to cylinder end. Return oil from The lift check valve prevents dropping of the blade
cylinder flows around spool to reservoir through cavi- during engagement of the spool into a power position.
ties inside the valve.
The weight of the blade creates a pressure on the
cylinder oil. When the valve spool is moved into a
power position this pressure is directed to the top of the
lift check valve. This pressure keeps the lift check valve
seated until the pressure oil directed to the bottom of
the lift check overcomes the pressure created by the
weight of the blade.

Litho in U.S.A.
 32 Dozer JD750 Crawler Bulldozer
3260-12 Dozer Hvdra ulics TM- 1136 (Nov-78)

_,.
REMOVAL

Operate control valve lever until all hydraulic pres- If dozer control valve is to be removed for servicing
sure is relieved. and it is believed that fragments of failed valve parts
may have entered the dozer hydraulic system, replace
Release pressure in reservoir by slowly removing or clean the hydraulic filters.
filler cap at top of tank.

REPAIR

T51797F

l-Special Cap Screw (2 used) &O-Ring 15-Breather Washer

2-Gap Assembly 9-Hydraulic Valve %-O-Ring
3-Spool Screw lo-Lift Check Plunger 17-Hydraulic Valve
4-Spool Washer ll-Lift Check Spring 18-Plug with O-Ring
5-Lift Check Spring (2 used) 12-Screw Machine (2 used) 19-Backup Washer (2 used)
S-Spool Washer U-Dust Seal 20-O-Ring (2 used)
7-O-Ring Retainer M-Dust Cap Retainer 21-O-Ring (2 used)
22-Relief Valve Cavity Plug (2 used)
Fig. 11 -Exploded View of Tilt Section 23-Relief Valve Cavity Plug Assembly

Service individual valves separately. Be sure valve Remove end caps and remove spools from valve
bodies and their spools are kept together because housings.
these parts are matched.
Clean and dry all parts thoroughly and inspect for
Remove tie bolts and separate valve sections. wear or damage.

Litho in U.S.A.
,JD750 Crawler Bulldozer Dozer 32
TM- 1136 (No v-78) Dozer Hydraulics 3260-13

6 78
5
\\I
t&IQ

T56470F

l-Special Cap Screw g-Hydraulic Control Valve 17-Spring

2-Detent Cap Assembly lCr--Relief Valve (2 used) la--Lift Check Plunger
3-Spool Detent Screw Ii-Backup Washer (2 used) 19-Screw Machine (2 used)
4-Shallow Spool Washer 12-O-Ring (2 used) 28-Dust Seal
S-Centering Spring 13-Anti-Cavitation Plunger 21-Dust Cap Retainer
&-Deep Spool Washer 14-Spring 22-Breather Washer
7-O-Ring Retainer 15-Anti-Cavitation Plug with O-Ring 23-O-Ring
&O-Ring 16Plug with O-Ring 24-Hydraulic Control Valve

Fig. IPExploded View of Lift Section

Remove plugs from bottom of tilt section. inspect Replace all O-rings.
plunger for damage and replace if necessary.
Remove burrs from spool assembly parts with fine
Check the spring for fatigue. Replace O-rings. emery cloth. If spools are worn or damaged, replace
spool and valve housing as a matched assembly.
Check valve housings for damage. If replacement
is necessary, replace housing and valve spool as a Discard old O-rings and backup washers, and use
matched assembly. new O-rings and seal kit when reassembling.

Discard old O-rings and use new O-rings and seal Lift checks may be removed after tie bolts are
kit when reassembling. removed.

Remove check valve from lift arm valve section. Inspect the lift checks and replace damaged parts
if necessary. Check the spring for fatigue.
Inspect the check valve and replace damaged
parts as necessary. Check the spring for fatigue. Replace all O-rings.

Lifho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3280-14 Dozer Hydraulics TM-l 136 (Nov-78)

l-Cartridge 5-Spring 8-O-Ring

2-O-Ring GSeat ll+End Plug
3-Spring Guide 7-Backup Washer 1 l-Retainer
4-Shims (As Required) 8-O-Ring 12-Snap Ring

fig. 13-Exploded View of Direct-Acting Relief Valve Assembly

Litho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (Apr- 79) Dozer Hydraulics 3260-I 5

Remove circuit relief valves from lift valve housing. Thoroughly clean and dry all parts. Oil all parts
lightly prior to assembly.
Position the hex. head of the relief valve cartridge
in a vise and remove snap ring and retainer. Replace all O-rings and backup washers with new
parts.
Remove parts from valve cage.
Install spools in proper valve section.
Thoroughly clean and dry all parts. Inspect parts
and replace as necessary. Stack port plate, valve sections, and end plate in
proper sequence.
When assembling the relief valve, be sure to use
all the shims removed. Install tie bolts. Tighten tie bolts to 30 to 35 lb-ft (41
to 47 Nm) (4 to 5 kg-m).
Assemble parts in cage and install retainer and
snap ring. INSTALLATION
Install control valve in dozer and connect linkage
Test pressure setting of the relief valve. If not to
and oil lines. Be sure packings are seated in connec-
specifications, replace cartridge.
tions before tightening lines to control valve. Be sure
flexible lines between engine frame and equipment
Individual parts for pilot-operated type relief valves
frame are installed straight and parallel, and do not
are not available separately.
sag.

Remove filter screen and pilot body and clean in a

Fill reservoir with clean oil and run dozer to check for
suitable solvent. Reassemble and test pressure set- proper operation and for leaks.
ting. If not to specifications, replace the cartridge.

Replace all O-rings.

Litho in U.S.A.
32 Dozers JD750 Crawler Bulldozer
3260-l 6 Dozer Hydraulics TM- 1136 (Aor- 79)

CYLINDERS
GENERAL INFORMATION REMOVAL

m6
See “Hydraulic Cylinders” in FOS Manual -
HYDRAULICS for additional information on A CAUTION: Be sure the engine is stopped
and the blade is resting on the ground
cylinders and an explanation of the hydraulic before attempting to remove cylinders.
cl 0 cushion design.
Operate the control valve levers until all hydraulic
Two double acting hydraulic cylinders are used to pressure is relieved.
raise and lower the blade. Both cylinders contain pop-
pets in the cylinder piston. These poppets reduce the Remove the hoses and cap them to prevent dirt from
forces created when the blade is raised or lowered in entering the system.
the tilted position.
NOTE: Before removing yoke caps, scribe a mark
The blade is tilted by one double acting cylinder on across the yoke and yoke caps to insure correct loca-
the hydraulic tilt dozer. The hydraulic tilt angle dozer tion when installing. Yoke caps are matched with the
blade is tilted by two single acting cylinders. Both yoke.
cylinders contain bypass valves in the cylinder pistons.
Refer to Group 9025 for further information on tilt Remove cap screws and end cap from lift cylinder
cylinders and bypass valve operation. rod and remove the cylinder.

Litho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (Apr- 79) Dozer Hydraulics 3260-17

REPAIR

rilt Cylinders

l-Barrel and Head 6-Seal 12-Backup Ring

Z-Special Nut 7-Seal 13-Rod Guide
3-Piston Assembly &Washer 14-Oil Seal
Q-Piston Wear Ring 9-Rod Seal 1 S-Washer
5-O-Ring lo--Wear Ring M-Cap Screw (4 used)
1 l-O-Ring 17-Piston Rod

Fig. 74-E/t Cylinder

(Hydraulic Ti/t Angle Dozer)

litho in U.S.A.
32 Dozer JO750 Crawler Bulldozer
3260-18 Dozer Hvdraulics TM- 1136 (Apr- 79)

l-Plug 7-ORing 13-Wear Ring

2--O-Ring 8-V-Packing 14-O-Ring
3-Barrel and Head g-Piston 1 &Backup Ring
4-Special Nut 1 O-Set Screw 16-Rod Guide
6-Piston 1 l-Internal Snap Ring 17-Oil Seal
6-Piston Wear Ring 12-V-Packing 18-Piston Rod

Fig. IdTilt Cylinder

(Hydraulic Tilt Dozer)

Litho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (Apr- 79) Dozer Hydraulics 3260-19

Wash all parts thoroughly with diesel fuel and in-

spect the following:

1. Barrel, rod guide and rod for scoring, and O-rings

for surface damage.

2. V-packings and wear rings for breaks, cuts or

embedded foreign material.

3. Piston rod seal and wiper for wear or damage.

Remove sharp edges from piston rod with emery cloth.

4. Valve guides, steel balls, spring, shafts, and pin

for damage or fatigue. (hydraulic tilt angle dozer only) I

Repair kits are available for overhauling all cylin-

ders. Discard used parts and use all new parts provid-
ed in kits when assembling cylinders.

Lubricate all O-rings, seals, and packings before

assembly.

Install the bypass valve components. Refer to figure

16. Tighten valve guides to 70 2 7 lb-in (7.8 c 0.7 Nm)
T64424Ii
(hydraulic tilt angle dozer only).
l-Piston Seal Ring &Pin
2-Seal g--Washer
3-Valve Guide (2 used) IO-Piston Rod
4-Shaft 1 l-O-Fling
5-Seal Ring (2 used) 1 P-Piston
6-Steel Ball (2 used) 13-Special Nut
7-Spring

Fig. !6-Tilt Cylinder Piston Assembly Cutaway

(Hydraulic Tilt Angle Dozer)

If cylinder packings have failed, some fragments of

the deteriorated parts may have entered the system.
Replace filter and clean filter housing.

Clamp the cylinder in a vise to prevent it from

turning. Remove bolts and rod guide.

Remove piston rod, rod guide and piston from bar-

rel.

Clamp the rod end in a vise taking care to prevent

damage to the piston rod. Remove nut from end of rod. T57126N
Slide parts from end of rod. l-O-Ring 4-Wear Ring
2-Backup Ring 5-Wiper Seal
Remove the valve guides and bypass valve internal 3-Rod Seal
components (Fig. 16). (hydraulic tilt angle dozer only)
Fig. 17-Rod Guide Components I
(Tilt Cylinder-Hydraulic Tilt Angle Dozer)

Litho in U.S.A.
 32 Dozer JD750 Crawler Bulldozer
3260-20 Dozer Hydraulics TM- 1136 (Apr- 79)

Install new wiper seal in rod guide. Installing Piston V-Packing

Install new wear ring in rod guide. Position backup

washer and O-ring on rod guide.

Install V-packing in rod guide with the apex of the V

toward the wear ring and secure with snap ring.

Slide rod guide assembly on piston rod being careful

not to damage packing.

l'S713ON

l-Nut 5-V-Packing
2-Piston GPiston
3-Wear Ring 7-Cylinder Barrel
4-O-Ring

Fig. 19-Original Installation of V-Packing

T5?1%9N
l-O-Ring 4-W Packing
2-Backup Ring %-Wear Ring
3-Snap Ring 6-Wiper Seal

I Fig. IS-Rod Guide Components

(Tilt Cylinder - Hydraulic Ti/t Dozer)

Litho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (Apr- 79) Dozer Hydraulics 3260-21

V-packings are originally installed on the piston with

the apex of the V pointing away from the barrel (Fig.
19). When repla.cing V-packings in the field this pro- (
cedure can be used if a suitable ring compressor is
available to compress packings when installed in cyl-
inders.

If a suitable compressor is not available, assemble

the packings with the apex of the V pointing toward the
barrel (Fig. 20). This eliminates scuffing that may occur [
in assembly; however, the V-packing may become torn
if the cylinder has to be disassembled in the future.

Position pistons on rod and install wear ring (3).

Secure with stop nut. Tighten nut (2, Fig. 14) or (4, Fig.
15) to 982 t 23 lb-ft (1400 Z? 100 Nm).
iT5713ib
IMPORTANT: The piston assembly (Fig. 16)
l--Nut S-V-Packing
2--Piston GPiston must be installed on the piston rod with’the relief
3-Wear Ring 7-Cylinder Barrel guide in the position shown in Fig. 21.
&-O-Ring
Install piston rod assembly into barrel.
Fig. 204nstallation of V-Packing Without Compressor

Secure piston rod assembly in barrel with rod guide.

Tighten cap screws (16, Fig. 14) to 670 ? 67 lb-ft (908
-c 90 Nm). Tighten the rod guide (16, Fig. 15) to 250 to
300 lb-ft (339 to 407 Nm). Tighten set screw (10) to 40
lb-in (4.5 Nm).

l--Relief Guide 3-Piston Rod

2-Piston Assembly

Fig. Pl-Piston to Rod Assembly

(Hydraulic Tilt Angle Dozer)

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3260-22 Dozer Hydraulics TM- 1136 (Apr- 79)

!757132B

l-Plug 9-Poppet (4 used) l7-Backup Ring

2-D-Ring lo-Spring (2 used) 18-Rod Guide
3-Barrel and Head 11-O.Ring (2 used) Is-Wiper Seal
4-Set Screw 12-Piston Wear Ring 20-Piston Rod
6-Special Nut 13-Dowel Pin 21-Ball Pivot Cup
g--Piston (2 used) 14-Rod Seal 22-Shim (use as required)
7-Seal (2 used) 16-Wear Ring 23-Lock Washer (2 used)
8-Seal (2 used) 16-D-Ring 24-Gap Screw (2 used)

Fig. 22-Lift Cylinder

(Hydraulic Tilt and Hydraulic Tilt Angle Dozers)

NOTE: Lift cylinders on hydraulic tilt dozers prior to 267005 used only one O-Ring (11).

Litho in U.S.A.
 JD750 Crawler Bulldozer Dozer 3%
TM- 1136 (Apr- 79) Dozer Hydraulics 3260-23

Clamp the cylinder in a vise to prevent it from

turning. Remove set screw and rod guide or spanner
nut. Use a spanner wrench to loosen rod guide.

Remove piston rod, rod guide and piston from bar-

rel.

Clamp the rod end in a vise taking care to prevent

damage to the piston rod. Remove nut from end of rod.
Slide parts from end of rod.

Wash all parts thoroughly with diesel fuel and in-

spect the following:

1. Barrel, rod guide and rod for scoring, and O-rings

for surface damage.

2. Seals and wear rings for breaks, cuts or embed-

ded foreign material.
257133N

3. Piston rod seal and wiper for wear or damage.

Remove sharp edges from piston rod with emery cloth. l-Wiper Seal 4-O-Ring
l-Wear Ring CL-Rod Seal
3-Backup Ring
Repair kits are available for overhauling all cylin-
ders. Discard used parts and use all new parts provid- Fig. 23-&d Guide Components
ed in kits when assembling cylinders.
Install new wiper seal in rod guide.
Lubricate all O-rings, seals, and packings before
assembly. Install new wear ring in rod guide. Position backup
ring and O-ring on rod guide.

Install rod seal.

Slip rod guide assembly on piston rod.

Lifho in U.S.A.
--
 32 Dozer JD750 Crawler Bulldozer
3260-24 Dozer Hvdraulics TM- 1136 (Apr- 79)

Piston Assembly

l-Nut 6-O-Ring (2 used)

2-Seal (2 used) 7-Poppet (4 used)
‘3-Seal (2 used) 8-Spring (2 used) l-Poppet 3-Dowel Pin
4-Piston (2 used) %-Dowel Pin 2-Spring
&Piston Wear Ring
Fig. 26-Installing Pistons on Piston Rod I
Fig. 24-Piston Assembly

Install poppets and springs between pistons and slip

Install O-rings (6, Fig. 24) in pistons.
on piston rod.

Install inner seals (3) on pistons.

l-Nut 2-Wear Ring

Fig. 27-Installing Nut and Wear Ring I

Install nut (1) on piston rod. On lift cylinder for

Fig. 25-/nsta//ing Outer Seal
hydraulic tilt dozer, tighten nut (1) to 600 to 700 lb-ft
(813 to 949 Nm) (83 to 97 kg-m). On lift cylinder for
Install outer seals (2) on piston as shown in Fig. 25.
hydraulic tilt angle dozer, tighten nut (1) to 350 to 400
Note that rear of seal is high on piston and that area
lb-ft (475 to 542 Nm) (48 to 55 kg-m).
being pressed on is away from sharp edges of piston
grooves.
Install wear ring (2).

bitho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (Apr- 79) Dozer Hydraulics 3260-25

Apply light coat of grease to pistons, seals and wear Secure piston rod assembly in barrel with rod guide
ring. and tighten spanner nut to 250 to 300 lb-ft (339 to 407
Nm) (35 to 41 kg-m).
Place blocks under rod and barrel to obtain align-
ment of rod to barrel. Tighten set screw to 40 lb-in (4.5 Nm) (0.46 kg-m).

Install ring compressor over seals and wear ring and INSTALLATION
compress seals for approximately 5 minutes.
Place cylinder in position on the machine and install
attaching hardware.
Remove ring compressor.
On lift cylinders, tighten cap screws to 170 lb-ft (230
Nm) (24 kg-m).

If new cylinders are installed, connect lift cylinder rod

to blade. Install end cap (without shims) and tighten
cap screws. Measure the gap between end cap and
rod end. Remove end cap and install enough shims
that would fill the gap plus one extra shim for clear-
ance. Reinstall end cap and tighten cap screws to 170
lb-ft (230 Nm) (24 kg-m).

Connect hydraulic lines, making sure they are con-

nected to the same ends of the cylinder from which
they were removed.

After installing the cylinder, operate the cylinder

several times to remove air from the svstem. Add oil to

q
Fig. 28-JO363 Tool
the reservoir to bring it up to the proper level.
Install JD363 tool and install rod into barrel.

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3260-26 Dozer Hydraulics TM- 1136 (Apr- 79)

Litho in U.S.A.
 JD 750 Crawler Bulldozer Dozer 32
Tbk1136 fMar-781 SDecifications and SDecial Tools 3299-l
I

Group 3299
SPECIFICATIONS AND SPECIAL TOOLS
MOVABLE FRAME
- ._ SPECIFICATIONS AND TORQUE VALUES

Trunnion Pivot Cap Bolts. 300 lb-ft

‘(4d7 ‘ii)’ 142 kg-m)

Fig. I-Trunnion Pivot Cap Bolts

DOZER HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES

,__.,__...,..................................... Tie bolt torque. . . . .30 to 35 lb-ft

I Dozer Control Valve
(41 to 47 Nm) (4 to 5 kg-m)

Dozer Tilt Valve 1 - Cap screw . . .. . . . . . . 10 to 13 lb-ft

(14 to 18 Nm)
(1 to 2 kg-m)

2 - Spool screw . . . . . . . . . . . . . . . . . . . . 5 to 8 lb-ft

(7 to 11 Nm)
(0.7 to 1 kg-m)

3 - Lift check spring.. . . . . 1.452 in. (36.88 mm)

with 30 lb. (134 N) (14 kg)
1748776-N

Fig. P-Dozer Tilt Valve Section 4 - Lift check spring.. . .. 0.875 in. (22.23 mm)
with 3 lb. (13 N) (1 kg)

Litho in U.S.A.
 32 Dozer JD750 Crawler Bulldozer
3299-2 SDecifications and SDecial Tools TM- 1136 (Mar-781

Group 3299
SPECIFICATIONS AND SPECIAL TOOLS
DOZER HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES-Continued

Dozer Lift Valve

El T44075N

Fig. 3-Dozer Lift Valve Section I

1 - Cap screw.. .. . . . . . 5 to 8 lb-ft 4 - Relief valve setting ..... .... . . . .2250 psi
(7 to 11 Nm) (155 bar)
(0.7 to 1 kg-m) (158 kg/cm2)
Relief valve torque must exceed . . . . 15 lb-in.
2 - Spool detent screw . . . . . . . . . . . . . . . 5 to 8 lb-ft (1.7 Nm)
(7 to 11 Nm) (0.17 kg-m)
(0.7 to 1 kg-m)
5 - Spring.. . . . . . . . . . . . . . . .0.625 in. (15.88 mm)
3 - Centering spring 1.452 in. (36.88 mm) with 0.75 lb. (3 N) (0.3 kg)
‘with’30 lb. (134 N) (14 kg)
6 - Spring.. . . . . ~. . . . . . . .0.875 in. (22.23 mm)
with 3 lb. (13 N) (1 kg)

Litho in U.S.A.
JD750 Crawler Bulldozer Dozer 32
TM- 1136 (Am- 79) SDecifications and ScJecial Tools 3299-3

DOZER HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES-Continued

Tilt Cylinder (Hydraulic Tilt Angle Dozer)

1 - Cylinder bore . . . . . . . . , . . . 5.498 in. (140 mm)

2 - Rod diameter .. ... . . .2.5 in. (63.5 mm)

3 - Cylinder stroke . . . . . . .4.33 ? 0.12 in.

(110 + 3 mm)

4 - Stop nut,. . .. .. . ... .982 & 23 lb-ft

(1400 + 100 Nm)
Fig. 4Tili Cylinder (Hydraulic 5 - Cap screw. . . ..... .670 & 67 lb-ft
Tilt Angle Dozer) (908 -c 90 Nm)

Tilt Cylinder (Hydraulic Tilt Dozer)

1 - Cylinder bore . . .. ... . 5.5 in. (140 mm)

2 - Rod diameter . ........ . . 2.5 in. (64 mm)

3 - Cylinder stroke . . .. .. . . .5.77 i 0.12 in.

(145 i 3 mm)

4 - Stop nut. . . . . . . . . . . . . 1000 to 1200 lb-ft

(1.356 to 1 627 Nm) (138 to 166 kg-m)

Fig. 5-T//t Cylinder (Hydraulic Tilt 5 - Rod guide ........... . . 250 to 300 lb-ft
Dozer)
(339 to 407 Nm) (35 to 41 kg-m)

6 - Set screw .,....... .. . . . . . . .40 lb-in

(4.5 Nm) (0.46 kg-m)

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3299-4 Dozer Hydraulics TM- 1136 (Apr- 79)

DOZER HYDRAULICS
SPECIFICATIONS AND TORQUE VALUES-Continued

Lift Cylinder (Hydraulic Tilt Dozer)

1 - Cylinder bore . ... .. . . 4.25 in. (108

2 - Rod diameter . . .. . . . .2.5 in. (63.5

3 - Cylinder stroke . . . . . ... . .31.85 + 0.12 in.

(809 2 3 mm)

4 - Stop nut.. . . . . . . . . . . 600 to 700 lb-ft

Fig. &Lift Cylinder
(813 to 949 Nm) (83 to 97 kg-m)

5 - Rod guide ... . . . 250 to 300 lb-ft

(339 to 407 Nm) (35 to 41 kg-m)

6 - Set screw . .. .. . . 40 lb-in.

(4.5 Nm) (0.46 kg-m)

7 - Cap screw.. . .. .. _. . . . . . . . 170 lb-ft

(230 Nm) (24 kg-m)

Lift Cylinder (Hydraulic Tilt Angle Dozer)

1 - Cylinder bore . . . . . . 4.25 in. (108 mm)

2 - Rod diameter . . . .. . . 2.50 in. (64 mm)

3 - Cylinder stroke .. . . . .32.05 ? 0.12 in.

(814 ? 3 mm)

4 - Stop nut. . . . .. . . . 350 to 400 lb-ft

(475 to 542 Nm) (48 to 55 kg-m)

5 - Rod guide . . . . . . . . . 250 to 300 lb-ft

(339 to 407 Nm) (35 to 41 kg-m)

6 - Set screw . . . . . . . . .40 lb-in

(4.5 Nm) (0.46 kg-m)

7 - Cap screw.. . . ,. . . . . . . . . . . 170 lb-ft

(230 Nm) (24 kg-m)

Litho in U.S.A.
JO750 Crawler Bulldozer Dozer 32
TM- 1136 (Mar-78) Specifications and Special Tools 3299-s

HYDRAULIC SYSTEM
SPECIAL TOOLS

Essential Tools

Tool Tool No. Use

JD363 Seal Installation Tool - Install rod

with seals in barrel on lift cylin-
ders.

Fig. 7-Seal /nsfa//afion Tool

Convenience Tools

Tool Tool No. Use

D-051 14ST Remove and Install cylinder span-

ner nuts

Fig. a-Spanner Wrench

Litho in U.S.A.
32 Dozer JD750 Crawler Bulldozer
3299-6 Specifications and Special Tools TM-1 136 (Mar-78)

..

Litho in U.S.A.
JD750 Crawler Bulldozer Ground Conditioning Tool 42
TM- 1136 IFeb- 77) Blades. Teeth. Shanks 4201-l

Section 42
GROUND CONDITIONING TOOL
CONTENTS OF THIS SECTION
1
Page Page r5
GROUP 4201 - BLADE, TEETH, SHANKS GROUP 4260 - HYDRAULIC SYSTEM
Ripper Double Selector Valve:
General Information .................. 4201-3 General Information .................. 4260-l
Removal ............................ 4201-3 Removal ............................ 4260-I
Repair .............................. 4201-3 Repair .............................. 4260-2
Installation. .......................... 4201-3 Installation. .......................... 4260-2

GROUP 4215 - CONTROLS LINKAGE

Auxiliary Control Linkage:
General Information .................. 4215-1
Removal ............................ 4215-2
Repair .............................. 4215-4
Adjustment .......................... 42154
Installation. .......................... 42154

Litho in U.S.A.
42 Ground Conditioning Tool JD750 Crawler Bulldozer
4201-2 Blades, Teeth, Shanks TM- 1136 (Feb-77)

Litho in U.S.A.
JD750 Crawler Bulldozer Ground Conditioning Tool 42
TM- 1136 (Feb-77) Blades, Teeth, Shanks 4201-3

Group 4201
BLADES, TEETH, SHANKS

GENERAL INFORMATION
A ripper (optional) mounts to rear of crawler (see
Fig. 1).

Mounting studs screw into back of crawler. Nuts

screw on studs to hold ripper mounting plate.

A hydraulic cylinder on the ripper raises and lowers

the ripper.

REMOVAL
Lower ripper to ground.
T46763~
Move ripper control valve lever back and forth to
relieve hydraulic pressure. Move lever until no re- Fig. I-Ripper Mounted on Crawler
sponse is felt.
INSTALLATION
Disconnect ripper hydraulic hoses. Plug or cap fit- Raise ripper with hoist and position at rear of
tings to prevent dirt from entering hydraulic system. crawler.

Attach hoist to ripper.

Remove cap screws holding ripper mounting plate to

rear of crawler.

Drive crawler forward slowly to remove ripper.

REPAIR
Inspect all parts for cracks or wear. Replace as
necessary.

Litho in U.S.A.
42 ’ Ground Conditioning Tool JD 750 Crawler Bulldozer
4201-4 Blades, Teeth, Shanks TM- 1136 (Feb-77)
JD750 Crawler Bulldozer Ground Conditioning Tool 42
TM- 1136 (Apr- 79) Controls Linkage 4215-l

Group 4215
CONTROLS LINKAGE
AUXILIARY CONTROL LINKAGE

18
\

16- 15

@
T44928

l-Cap Screw 7-Auxiliary Control Bell Crank 13-Ball Joint End (2 used)
2-Lock Washer E-Nut 14-Nut (2 used)
3-Retaining Ring g-Auxiliary Control Lever 1 !&Auxiliary Lever Rod
4-Auxiliary Control Shaft 1 O-Knob 16-Bushing
S-Nut (2 used) 1 l-Bushing (2 used) 17-Support Bracket
6-Lock Washer (2 used) 12-Cap Screw (2 used) l&Spring Pin

Fig.I-Auxiliary
ControlLever

GENERAL INFORMATION When the auxiliary control lever is pushed forward,

pressure oil is directed from the tilt control valve to the
The auxiliary control linkage activates the double
tilt cylinder. Moving the tilt control lever to the right will
selector valve. The double selector valve will direct
pressurize to the rod end of the tilt cylinder causing the
pressure oil from the tilt control valve to the tilt or ripper
blade to tilt right.
cylinders.

Litho in U.S.A.
 42 Ground Conditioning Tool JD750 Crawler Bulldozer
4215-2 Controls Linkage TM- 1136 (Apr- 79)

l’45304N

l-Groove Pin (4 used) 6-Lock Washer (2 used) lo-Lift Lever

2-Lever (2 used) 7-Bracket 1 l-Cap Screw
1 3-Lift Shaft s-Bushing (6 used) 12-Auxiliary Control Shaft
4-lilt Shaft g-Tilt Lever 13-Cotter Pin
!&Cap Screw U-Auxiliary Control Lever
16-Double Selector
Valve Cable

Fig. P-Control Shaft Bracket With Double Selector Valve

Moving the tilt control lever to the left will pressurize REMOVAL
to the head end of the tilt cylinder causing the blade to On units without cab remove outside right panel
tilt left. When the auxiliary control lever is pushed
from equipment control box.
backward, pressure oil from the tilt control valve is
directed to the ripper cylinder. On units with cab remove right console cover.

Moving the tilt control lever to the right will lower the Remove floor plate.
ripper. Moving the tilt control lever to the left will raise
the ripper.
Remove rear fender on right side.

Remove belly pan. This will allow for removal or

work on the entire linkage. If a specific portion of the
linkage is to be worked on only remove as much as
needed to work or remove that specific part.

NOTE: Thoroughly coat the inside of bushings (8,

Fig. 2) with John Deere Never Seez or an equivalent
prior to inserting the control shafts.

Litho in U.S.A.
JD750 Crawler Bulldozer Ground Conditioning Tool 42
TM- 1136 (Feb-77) Controls Linkage 4215-3

T44920

l-Nut (2 used) 6-Nut lO-Clamp (4 used)

2-Lock Washer (2 used) 7-Lock Washer (3 used) 1 l-Cap Screw
3-Ball Joint End (2 used) &Cap Screw (2 used) 12-Push-Pull Cable
4-Jam Nut (2 used) 9-Bracket 13-Spacer
5-Cap Screw (2 used) 14-Double Selector Valve

Fig. 3-Selector Va/ve Linkage (With Cab)

Litho in U.S.A.
42 Ground Conditioning Tool JD750 Crawler Bulldozer
4215-4 Controls Linkage TM- 1136 (Feb-77)

T44919

l-Nut (2 used) 6-Nut 1 O-Cap Screw

2-Lock Washer (2 used) 7-Lock Washer (3 used) 1 l-Spacer
3-Ball Joint End (2 used) 8-Tube Clamp Plate 12-Push-Pull Cable
4-Jam Nut (2 used) 9-Clamp (4 used) 13-Cap Screw
5-Cap Screw (2 used) U-Double Selector Valve

Fig. 4-Selector Valve Linkage (Without Cab)

REPAIR Adjust push-pull cable (12, Figs. 3 and 4) so the ball

joint end (3, Figs. 3 and 4) is in line with the double
Inspect control valve linkage for worn or damaged
selector valve lever.
parts and replace as necessary.
Install cap screw (5, Figs. 3 and 4), lock washer (2)
ADJUSTMENT and nut (1).
Put auxiliary control lever in the forward position.
INSTALLATION
Reverse the removal procedure.

Litho in U.S.A.
 JD750 Crawler Bulldozer Ground Conditioning Toel 42
.I
TM- 1136 (Nov-75) Controls Linkage 4215-5

AUXILIARY

VALVE ----WI I

144920

l-Nut (2 used) 6-Nut lO--Clamp (4 used)

2-Lock Washer (2 used) 7-Lock Washer (3 used) 1 l-Cap Screw
3--Ball Joint End (2 used) &-Cap Screw (2 used) 12-Push-Pull Cable
4-Jam Nut (2 used) 9-Bracket 13-Spacer
!&Cap Screw (2 used) 14-Double Selector Valve

Fig. 3-Selector Valve Linkage (With Cab)

Litho in U.S.A.
42 Ground Conditioning Tool JD750 Crawler Bulldozer
4215-6 Controls Linkage TM- 1136 (Nov-75)

AUXILIARY

T44919

l-Nut (2 used) 6-Nut lO-Cap Screw

2-Lock Washer (2 used) it-Lock Washer (3 used) 1 l-Spacer
3-Ball Joint End (2 used) &Tube Clamp Plate 12-Push-Pull Cable
4-Jam Nut (2 used) 9-Clamp (4 used) 13-Cap Screw
5--Cap Screw (2 used) 14-Double Selector Valve

Fig. 4-Selector Valve Linkage (Without Cab)

REPAIR Adjust push-pull cable (12, Figs. 3 and 4) so the ball

joint end (3, Figs. 3 and 4) is in line with the double
Inspect control valve linkage for worn or damaged
selector valve lever.
parts and replace as necessary.

Install cap screw (5, Figs. 3 and 4), lock washer (2)
ADJUSTMENT
and nut (1).
Put auxiliary control lever in the forward position.
INSTALLATION
Reverse the removal procedure.

Litho in U.S.A.
JD 750 Crawler Bulldozer Ground Conditioning Tool 42
TM- 1136 (Nov-78) Hydraulic Sys tern 4260-l

Group 4260
HYDRAULIC SYSTEM
DOUBLE SELECTOR VALVE

T45306N

l-Selector Valve Bracket 3-Cap Screw (2 used)

2-Lock Washer (4 used) e-Cap Screw (2 used)

Fig. Z-Selector Valve Bracket

REMOVAL
3
T45305N tf CAUTION: Escaping fluid under pressure
a can have sufficient force to penetrate the
l-Tilt Control Valve 3-Tilt Cylinder skin, causing serious personal injury. Before dis-
Ports A and B Ports C and D
connecting lines, be sure to relieve all pressure.
2-Ripper Cylinder Ports
Before applying pressure to system, be sure all
E and F
connections are tight and that lines, pipes and
Fig. I-Double Se/e&or Valve hoses are not damaged. Fluid escaping from a very
small hole can almost be invisible. Use a piece of
GENERAL INFORMATION cardboard or wood, rather than hands, to search
The double selector valve is located on the right side for suspected leaks.
of the main frame next to the engine below the engine
If injured by escaping fluid, see a doctor at once.
fuel filter.
Serious infection or reaction can develop if proper
medical treatment is not administered immediate-
The double selector valve will take pressure oil from
the tilt control valve and direct it to either the tilt or ly.
ripper cylinder.
Remove dozer control valve cover plate.
With the auxiliary lever forward, pressure oil from the
Remove and cover hydraulic lines.
tilt control valve is directed through the double selector
valve to the tilt cylinder.

With the auxiliary lever pushed backward, pressure

oil from the tilt control valve is directed through the
double selector valve to the ripper cylinder.

Litho in U.S.A.
42 Ground Conditioning Tool JD750 Crawler Bulldozer
4250-2 Hydraulic Sys tern TM-1 136 (Nov-78)

Remove linkage from double selector valve. INSTALLATION

Install double selector valve.
Remove cap screws (4, Fig. 2) and lock washers (2).

Install cap screws (4, Fig. 2) and lock washers (2).

Remove double selector valve.

Connect double selector valve linkage.

REPAIR
Refer to Fig. 3 for service parts on the double Connect hydraulic hoses.
selector valve.

l-Double Selector Valve 7-Lock Washer

24tetaining Ring (2 used) a--Spool End
3-Ouad Ring (2 used) g-Connecting Link
4-Spool lo-Cotter Pin
5-Rivet 11 -Lever
6-Cotter Pin

Fig. 3-Double Selector Valve

Litho in U.S.A.
 Section 90
SYSTEM TESTING
CONTENTS

Page Page
GROUP 900thOPERATIONAL CHECKOUT GROUP 9025-HYDRAULIC SYSTEM
PROCEDURE-HYDROSTA- (FLOW METER)
TIC’ CRAWLER ......... .9005-01 General Information .................... 902505
Operation .......................... 902508
GROUP 9010-ENGINE Diagnosing Malfunctions ................ 9025-l 4
General Information .................... 901 O-01 Visual Inspection ....................... 9025-l 7
Diagnosing Malfunctions ................ 901 O-05 Testing and Adjustments ................ 9025-l 8
Visual Inspection ....................... 901 O-08 Lift Control Valve .................... 902518
Testing and Adjustments ................ 901 O-l 0 Tilt Control Valve .................... 9025-18
Basic Engine ....................... 901 O-l 0 Tilt or Ripper Cylinder ................ 9025-19
Lubrication System .................. 9010-10 Lift Cylinder ........................ 9025-20
Cooling System ..................... 901 O-l 1 Hydraulic Sump ..................... 9025-20
Fuel System ........................ 9010-12 Hydraulic Pump Flow Test ............ 9025-21
Speed Control Linkage ............... 901 O-14
Air Intake System ................... 901 O-l 5 GROUP 9025A-HYDRAULIC SYSTEM
(ANALYZER)
GROUP 9015-ELECTRICAL SYSTEM General Information .................. .9025A-01
General Information .................... 9015-01 Pretest Inspection ................. .9025A-03
Diagnosing Malfunctions ................ 901514 Operational Checks ................ .9025A-03
Visual Inspection ....................... 9015-l 8 Test and Adjusments .............. .9025A-06
Testing and Adjustments ................ 901519 List of Parts for Tests .............. .9025A-12
Starting Circuit ...................... 9015-20
Charging Circuit ..................... 9015-26 Continued on next page
Lighting Circuit ...................... 901531
Instruments and Indicators ........... 9015-32
Miscellaneous Accessories ........... 901534

GROUP 9020-Power Train

General Information .................... 9020-01
Diagnosing Malfunctions ................ 9020-06
Visual Inspection ....................... 9020-07
Adjustments ........................... 9020-08

T59;9000 17 200184

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T76;9000
POiC
200184

.-
 Page Page
GROUP 9026-HYDRAULIC SYSTEM Theory of Operation-Continued
Special Tools . . . . . . . . . . . . . . . . . ~. . . . . . . . 9026-03 Control Circuit Diagram .............. 9026-31
Specifications: Pl Relief Valve ..................... 9026-34
Engine Power Test (Proc. 5) . . . . . . . . . . 9026-03 P2 Relief Valve ..................... 9026-35
Engine Speed Adjustment (Proc. 6) . . . . 9026-03 Variable Orifice ..................... 9026-35
Volumetric Efficiency Test (Proc. 8) . . . , 9026-04 Speed Control Valve (P3) ............ 9026-36
Charge Pressure Test (Proc. 9) . . . . . . . 9026-05 Automatic Control Valve ............. 9026-37
Cooling Circuit Test (Case Pressure) Automatic Control Valve Shut Off ..... 9026-38
(Proc. 10) . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-05 FNR Valve ......................... 9026-39
High Pressure Relief Valve Test Steering Valve ...................... 9026-40
(Proc. 11) . . . . . . . . . . . . . . . . . . . . . . . =e. 9026-06 Brake Valve ........................ 9026-42
Control Pressure Loss Isolation Oil Cooler Bypass Valve ............. 9026-43
Proc. 14) . . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-06 Diagnosing Malfunctions ................ 9026-44
Control Valve Pl Relief Valve Test General Drive Check (See the Opera-
(Proc. 17) . . . . . O.. . . . . . . . . . . . . . . . . . . 9026-06 tional Check-Out Proc. Section 9005)
Control Valve P2 Relief Valve Test Mistracking ......................... 9026-45
(Proc. 18) . . . . . . . . . . . . . . . . -. . . . . *. . . 9026-07 Crawler Will Not Move ............... 9026-46
Variable Orifice Installation Lack of Power and Cycling ........... 9026-47
(Proc. 19) . . . . . . . . . . . . . . . *. . . . . . . *. . 9026-07 Neutral Problems .................... 9026-48
Variable Orifice Pressure Adjustment Overheating ........................ 9026-49
(Proc. 20) . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-08 Test Procedures:
Neutral Band Adjustment (Proc. 21) . . . 9026-08 Proc. 01 General Testing Information . 902652
Full Speed Adjustment (Proc. 22) . . . . . 9026-09 Proc. 02 Transmission, Warm-up . . . . . 9026-61
Engine Pull Down Adjustment Proc. 03 Control Circuit Bleeding . . . . . 9026-62
(Proc. 23) . ~. . . . . . . . . . . . . . . . . . . . . . . . 9026-09 Proc. 04 Drain and Flush Hydrostatic
Automatic Control Valve Operational System . . . . . . . . . . . . . . . . . . . 9026-64
Check (Pro. 24) . . . . . . . . . . . . . . . . . . . . . 9026-09 Proc. 05 Engine Power Test
Accumulator P9 Operational Check (Turbo Boost) . . . . . . . . . . . . . 9026-66
(Proc. 25) . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-10 Proc. 06 Engine Speed (Fast and
Steering Valve Stops Adjustment Slow Idle) . . . . . . . . . . . . . . . . 9026-68
(Proc. 26) . . . . . . . . . . . . . . . . . . . *. . . . . . 9026-10 Proc. 07 Initial Start-up After
FNR and Engine Speed Linkage Transmission Repair . . . . . . . 9026-70
and Drag Adjustment (Proc. 31) a. . . . . . 9026-10 Proc. 08 Transmission Efficiency Test 9026-72
General Information: Proc. 09 Charge Pressure and
Dual Path Hydrostatic Drive System . . . 9026-l 1 Vacuum . . . . . . . . . . . . . . . . . . 9026-74
Theory Of Operation: Proc. 10 Cooling Circuit Test
Hydrostatic Transmission . . a. . . . . ~. . . . 9026-12 (Case Pressure) . . . . . . . . . . . . 9026-77
Circuit Diagram . . . . . . . . . . . . . . . . . . . . . 9026-l 5 Proc. 11 High Presure Relief Valve
Charge Pump . . . . . . . . . . . . . . . . . . . . . . . 9026-17 Test . . . . . . . . . . . . . . . . . . . . 9026-78
Pump Displacement Control Valve . . . . . 9026-18 Proc. 12 Isolate Transmission Charge
Motor Displacement Control Valve . . . . 9026-23 Pressure Loss . . . . . . . . . . . . . 9026-80
Manifold Valve Assembly . . . . . . . . . ~. . . 9026-24 Proc. 13 Pump Displacement Control
Transmission Bypass Valve . . . . . . . . . . ~ 9026-25 Valve Neutral Adjustment . ~. 9026-83
Transmission Operating Pressure Valve 9026-26
Control Circuit . . . . . . . . . . . . . . . . . . . . . . 9026-27 Continued on next page

T59;9000 14 110184

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T76;9000
POX100184
 CONTENTS-Coritinued

Page Page
Test Procedures-Continued Circuit Diagrams:
Proc. 14 Isolate Transmission Control Transmission Control Circuit . . . . . . . . 9026-l 15
Pressure Loss . . . _. . . . . . . . 9026- 85 Transmission Control Circuit
Proc. 15 Tracking Tests and (Pictorial) . . . . . . , . . . . . . . . . . . . . . . . . . 9026-l 16
Adjustments . . . . . . . . . . . . . 9026- 87 Hydrostatic Transmission
Proc. 16 Adjust Transmission Control Schematic ............ . .......... 9026-l 19
Valve After Repair . . . . . . . . 9026- 90 Control Linkage Component
Proc. 17 Transmission Control Valve Location . . . . . . . . . . . . . . . . . . . . . . . . _. 9026-l 20
Pl Adjustment . . . . . . . . . . . 9026- 91 Transmission Component
Proc. 18 Transmission Control Valve Location ..... ...... ............ 9026-l 23
P2 Adjustment . . . . . . . . . . . 9026- 92 Glossary of Terms . . . . . . . . . . . . . . . . . . . . . 9026-125
Proc. 19 Variable Orifice
Installation . . . . . . . . . . . . . . . 9026- 93 Continued on next page
Proc. 20 Variable Orifice Pressure
Adjustment . . . . . . . . . . . . . . 9026- 94
Proc. 21 FNR Lever Neutral Band
Adjustment P3 . . . . . . . . . . . 9026- 95
Proc. 22 Control Pressure Full Speed
Adjustment . . . . . . . . . . . . . . 9026- 96
Proc. 23 Automatic Control Valve
Adjustment (Engine Pull
Down) (P4) . . . . . . . . . . . . . . 9026- 97
Proc. 24 Automatic Control Valve
Operational Check . . . . . . . . 9026- 99
Proc. 25” Automatic Control Valve
Accumulator Check (P9) . . . 9026-100
Proc. 26 Steering Valve Stop
Adjustment . . . . . . . . . . . . . . 9026-l 01
Proc. 27 injection Pump and
Transmission Control
Valve Synchronization . . . . 9026-102
Proc. 28 Steering Linkage Ad-
justment . . . . . _. . . . . . . . . . . 9026-l 06
Prox. 29 Steering Counter-
Rotation Stop Ad-
justment . . . . . . . . . . . . . . . . . 9026-l 07
Proc. 30 Return To Neutral Linkage
Adjustment . . . . , . . . . . . . . . 9026-l 08
Proc. 31 FNR Speed Control Lever
Linkage Neutral Adjust-
ment . . . . . . . . . . . . . . . . . . . . 9026-l 09
Proc. 32 Brake Valve Cable
Adjustment . . . . . . . . . . . . . 9026-l 11
Proc. 33 Automatic Control Valve
Shut-Off Cable Ad-
justment . . . . . . . . . . . . . . . . . 9026-l 12

T59;9000 15 200184

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T76:9000
P03D
100184
 CONTENTS-Continued
Page
GROUP 9030-MISCELLANEOUS
COMPONENTS
Diagnosing Malfunctions ................ 9030-01
Tracks ........................... ..9030-0 1
Adjustments ........................... 9030-02
Track Tension ...................... 9030-02
Track Alignment 9030-02

GROUP 9031-HEATING AND AIR

CONDITIONING
Heating System ........................ 9031-01
General Information ................. 9031-01
Diagnosis and Testing ............... 9031-01
Air Conditioning System ................. 9031-05
General Information ................. 9031-05
Diagnosis and Testing ............... 9031-07
Operational Test .................... 9031-09
Electrical Test ...................... 9031-09
System Service ..................... 9031-l 0

GROUP 9035-SPECIFICATIONS AND

SPECIAL TOOLS
Engine .............................. ..9035-0 1
Specifications and Torque Valves ..... 9035-01
Special Tools ....................... 9035-03
Electrical System ....................... 903506
Specifications and Torque Valves ..... 903506
Special Tools ....................... 9035-l 3
Hydraulic Sysem (Flow Meter) ........... 9035-14
Specifications and Torque Valves ..... 9035-14
Hydraulic System (Analyzer) ............. 9035-l 5
Specifications and Torque Valves ..... 9035-15
Hydraulic System 9035-l 7
Special Tools ....................... 9035-l 7
Hydrostatic System ..................... 9035-l 8
Specifications and Torque Valves ..... 9035-18
Special Tools ....................... 9035-20
Air Conditioning System ................. 9035-21
Specifications and Torque Valves ..... 9035-21
Special Tools ....................... 9035-22
Miscellaneous Compponents ............ 903523
Specifications and Torque Valves ..... 903523

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Litho in U.S.A.
 Group 9005
OPERATIONAL CHECKOUT/HYDROSTATIC CRAWLER
1
USETHESESEVEN BASICSTEPSTO
DIAGNOSE AND TEST MACHINE

1. Know the system. In other words ‘Do your home- 4. Inspect the machine. Get off the machine and
work.” Study this manual to know how the individual make a visual check. Use your eyes, ears, and nose
components work and what their function is in the to spot signs of trouble.
over-all system.
Look closely at the components. Inspect for cracked
Keep up with the latest service information. Read and welds, loose tie bolts, damaged linkages, worn or
then file in a handy place. Information received today broken lines, etc.
may have the cause and remedy of a problem being
encountered. During the inspection, make a note of all the trouble
signs.
2. Ask the operator. Question the operator as to how
the machine acted when it started to fail. Find out what 5. List the possible causes. With the information
was unusual about it. obtained during steps 1 through 4, make a list of the
possible causes.
Also find out if any do-it-yourself service was per-
formed. (You may find out later that the trouble is What were the signs you found while inspecting the
somewhere else, but you should know if any compo- machine? What is the most likely cause?
nents were tampered with.) Ask how the machine is
used and when it is serviced. Many problems can be 6. Reach a conclusion. Look over the list of possible
traced to poor maintenance or abuse. causes and decide which are the most likely and which
are the easiest to verify.
3. Operate the machine. Get on the machine and
operate it. Warm it up and put it through its paces. Don’t “Diagnosing Malfunctions” given in the following
completely rely on the operator’s story; check it groups will be a helpful guide.
yourself.
Reach your decision on the leading causes and plan
Are the gauges reading normal? (If not, it may be that to check the first.
the component being monitored is not functioning
correctly or it may mean that the gauge is faulty.) 7. Test your conclusion. Before repairing compo-
nents in the system, test your conclusions to make sure
How’s the performance? Is the action slow, erratic, or they are correct.
nil? Do the controls feel solid or “spongy”? Do they
seem to be “sticking”? Some of the possible causes can be verified without
further testing. Check these possibilities first.
Smell anything? Any signs of smoke? Hear any unusual
sounds? Where? At what speeds or during what Test will soon narrow the remaining list of possible
cycles? causes and soon the actual source of trouble will be
pin pointed.

With the trouble accurately located, it is now a simple

matter to remove and repair the component at fault.

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 Operational Checkout ProcedureIHydros ta tic Crawler

OPERATIONALCHECKOUTPROCEDURE A location will be required which is level, has adequate

space to complete the driving checks, and work the
Use this systems checkout procedure to check all loader or dozer. No special tools or gauges are needed.
systems and functions on the hydrostatic crawlers If necessary, refer to Diagnosing Malfunctions Charts,
(655, 750, 755, 755A, 850, 855). Test and/or adjustment sections of the technical
manual when a problem is indicated or verification is
This checkout procedure is designed so the technician needed while perfoming the checkout procedure.
can make a quick check of the operation of the crawler
while sitting in the operators seat. The entire procedure Complete the necessary visual checks (oil levels, oil
can be done in less than 20 minutes when the condition, external leaks, loose hardware, loose link-
transmission and hydraulic oils are at operating temper- age, wiring connections, etc.) prior to doing the check-
ature. out procedure. T59;9005 130 060184

1. Battery Disconnect Switch, Gauges, NOTE: (850-855) If the solenoid on the fuel shut off
Fuel Shutoff Solenoid and Indicator does not ‘CLICK” this may indicate the sole-
Checks With Engine Stopped. noid is out of adjustment or not pulling fuel
shut-off lever against the stop for the run
ACTION: (Battery Disconnect Switch-If Equipped) position. If the solenoid is out of adjustment this
Turn battery switch “OFF” and key switch “ON”. could result in low power complaints.

IMPORTANT: DO NOT turn battery disconnect LOOK: The hydraulic and transmission oil filter restric-
switch to “off” position while engine tion indicator lights must be “‘ON”.
is running. This “load dumps” the
alternator, which could cause dam- LOOK: Hourmeter indicator must turn every few
age to the charging system. seconds.

LOOK: Voltmeter must indicate zero volts. LOOK: Observe water temperature and transmission
oil temperature gauges for later reference.
ACTION: (Battery condition)
Turn battery disconnect switch ‘ON”. ACTION: Air restriction indicator.
Open engine inspection door.
LOOK: Voltmeter must read over 20 volts.
LOOK: Air restriction indicator must NOT show red.
LISTEN: Injection pump solenoid must “CLICK”.
(850-855)

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 Operational Checkout ProcedureIHydrosta tic Crawler

2. Neutral Lock Lever, FNR Lever ACTION: (Neutral Start Switch)

And Neutral Start Switch Check. (Engine a. Key switch “ON”.
OFF) b. Put neutral lock lever down until a “CLICK” is
heard.
ACTION: (FNR Lever Lock) c. Depress start button.
a. Put FNR lever in neutral.
b. Put neutral lock lever in the “UP” position. LISTEN: Starter must not engage.
c. Apply “slight” effort on FNR lever and attempt
to move FNR forward. ACTION:
a. Put neutral lock lever up.
LOOK FNR lever must NOT move from neutral. b. Depress start button.

ACTION: ( FNR Lever Effort) LISTEN: Starter must engage.

a. Put neutral lock lever down.
b. Shift the FNR lever to full forward and full reverse
position.
c. Observe effort required to move lever.

FEEL: FNR lever must move smoothly and require

approximately 6 lbs force to move lever.

LOOK: FNR lever must contact stops at each end of

the quadrant.

NOTE: See Test Procedure 31 for FNR lever

adjustments.
T59;9005 132 241083

3. Gauge, Indicator, and Speed Control LOOK Voltmeter must read higher voltage. (This
Check With Engine Running. indicates alternator is charging.)

ACTION: ACTION: (Speed Control Linkage)

a. Place throttle at idle position. a. Put speed control lever at low idle.
b. Start engine. b. move speed control lever at approximately 1500
rpm.
LISTEN: Engine will increase in rpm after starting then c. Put speed control lever at high idle.
return to idle. (850-855)
LOOK The speedcontrollevermust contact the stops
NOTE: This is normal with the excess fuel feature of in the quadrant at low and high idle position.
injection pump. (850655)
FEEL: Speed control lever move smoothly and require
LOOK: Engine oil and transmission oil pressure gauge 19 lbs force to move lever.
must be in green zone.

NOTE: Cold hydraulic and transmission oil may cause

filter indicator lights to g/o w during initial oper-
ation. If transmission pressure is low with light
on, a restricted filter is indicated. If light comes
on at high rpm with transmission oil at oper-
a ting temperature a restricted filter is indicated.
If transmission pressure is low and the filter
light is out, a ineffiecient charge pump is
indicated. See Crawler Won’t Move Diagnostic
Flow Chart.
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 Operational Checkout ProcedureIHydros ta tic Crawler

I
4. Brake Linkage Checks

ACTION: (Brake Pedal Lock)

a. Depress brake pedal.
b. Apply brake pedal lock.
c. Attempt to move the FNR lever forward.

LOOK: Brake pedal must remain down.

LOOK: FNR lever must not move out of neutral.

T59:9005 134 0901

5. Disconnect Clutch Linkage And LOOK: Transmission charge pressure gauge indicator
Throw-out Bearing Checks (If Equipped) must drop to zero. This indicates the clutch is
disconnected.
ACTION: (Disconnect Clutch Check)
a. Operate engine at idle. LOOK: Diconnect clutch lever must remain in locked
b. Pull up on disconnect lever slowly and note free (disconnected) up position.
travel and feel of throw-out bearing.
c. Lock lever in up position. LOOK: The spring on disconnect clutch lever must
d. Unlock lever and observe lever movement. return lever to the down position.

LOOK: Lever must move freely and travel must be two NOTE: If the disconnect clutch linkage does not
inches to bring the clutch throw-out bearing completely release, the clutch components
against the clutch fingers. can be damaged.

Listen and Feel: No noise must be noted when

disconnect clutch is released and
throw-out bearing must not feel
rough.

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 Operational Checkout ProcedureIHydros ta tic Crawler

6. General Driving Checks-Hydrostatic

Transmission
ACTION: (Control Circuit Air Check)
a. Brake pedal and Tee handle up.
1
b. Operate engine at approximately 1500 rpm.
IMPORTANT: Track tension must be adjusted to c. Move FNR approximately 2 inches in quadrant
specifications for all following forward then back to neutral rapidly. Repeat in
checks. Hydrostatic Oil Temperature reverse.
Gauge Indicator must be in green d. Observe tracks as unit stops.
zone for these test.
LOOK Both tracks must come to a stop evenly and
ACTION: (Brake and Bypass Valve Leakage) to a complete stop.
a. Operate engine at low idle.
b. Note charge pressure gauge indicator. NOTE A track or tracks that is slow to stop
c. Depress brake pedal. indicates air in control circuit. See Control
Circuit Bleeding Procedure 3.
LOOK: Transmission charge pressure gauge indicator
will rise slightly. ACTION; (FNR Lever Neutral Band P-3 Adjustment.)
a. Operate engine at low idle.
NOTE A substantial charge pressure increase (34 b. Put Tee handle up.
needle widths) indicates leakage in brakes or c. Move FNR lever approximately one inch out of
bypass valve circuits, FNR lever out of neutral neutral, forward, then reverse.
or displacement control valves biased. See
Crawler Will Not Move Complaint and/or Lack LOOK: The crawler must move as the lever reaches
Of Power Or Cycling Complaints Diagnostic a position one inch from neutral in forward and
Flow Charts. reverse.

ACTION: (Transmission Neutral Checks) NOTE If tracks start to move before %i in., (or after
a. Brake pedal and tee handle up. l-1/2 inches of FNR lever movement) see
b. Stop, then restart engine and operate at low idle. FNR Lever Neutral Band Adjustment Proce-
c. Observe tracks when unit starts. dure 21.
d. Move FNR lever slowly forward until tracks move
then reverse until tracks move. ACTION: (Steering System Checks)
e. Move FNR lever back to neutral. a. Operate engine at approximately 1000 rpm
b. Tee handle up.
LOOK: Tracks must NOT move at start up. c. Put FNR lever approximately 1 inch in forward
position.
LOOK Was charge pressure highest with the FNR d. Pull LH steering lever or depress LH steering
lever some other position than neutral? pedal until track stops.
e. Observe charge pressure gauge.
NOTE: Charge pressure indicator will drop slightly as f. Pull LH steering lever or depress LH pedal into
the tracks begin to move forward or reverse. counter rotate position.
g. Observe charge pressure.
If charge pressure is higher out of neutral, leave h. Repeat procedure for RH steering lever or pedal.
FNR at point of highest charge pressure. Now
push each steering pedal or pull lever into LOOK The track being checked must stop and NOT
counter rotate position. If a track moves pump go into counter rotate when the lever or pedal
displacement control valve needs adjustment reaches the dead track position. (Increased
see Procedure 13. If tracks DO NOTmove, see lever or pedal effort position).
if FNR valve lever is on neutral detent. If not,
adjust linkage to lever in neutral position See LOOK: Charge pressure must NOT drop when one
FNR Speed Control Lever Linkage Neutral track is stopped.
Adjustment Procedure 3 1.
Continued on next page
If charge pressure drops in red, see Diagnostic
Flow Chart “Cra wler Will Not Move ” complaint.
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 Operational Checkout Procedure/Hydras ta tic Crawler

LOOK: The track being checked must counter rotate NOTE: The crawler should not change directions too
when lever or pedal is in the counter rotate aggresssively.
position.
To isolate whether problem of aggressive
NOTE: If the track being tested does not stop and/or speed change is caused by P9 accumulator or
goes into counter rotate in dead track position, P9 rate of rise orifice missing, put unit under
see Steering Linkage Adjustment, Procedure load with tee handle down.
28.
If unite cycles, problem is P9 accumulators tuck
If the track being tested does not counter or P9 orifice plugged.
rotate, see Steering Counter-Rotation Stop
Adjusment, Procedure 29. See Automatic Control Valve Accumulator
Check, Procedure 25.
A significant drop in charge pressure (34
needle widths) when one track is stopped Some experience with hydrostatic era wlers will
indicates leakage within the transmission help make this judgment easier to make.
which is powered. See Lack Of Power or
Cyclying Complaint Diagnostic Flow Chart.
ACTION: (Pump Phase Tracking Check)
ACTION: (Steering Linkage Interlock Check). a. Mark a line on the ground or establish a course
a. Operate engine at low idle. a length of 100 ft.
b. Tee handle up. b. Operate engine at high idle.
c. Move FNR lever approximately 1 inch forward. c. When crawler has been aligned in course DO
d. Pull both steering levers or depress both pedals NOT touch any controls.
to stop track position and observe tracks. d. Drive the crawler forward with FNR lever at l/3
FNR speed position in quadrant and Tee handle
LOOK: Only one lever or pedal should go in to counter- up*
rotate position. e. Observe how crawler tracks through marked
course.
NOTE: If both levers or pedals go into counter-rotate f. Repeat procedure in reverse.
position at the same time, the interlock linkage
is malfunctioning. See Steering Linkage Adjust- IMPORTANT: Track tension must be evenly ad-
ment, Procedure 28. justed and to specifications for all
tracking checks.
ACTION: (Automatic Control Valve Accumulator Check
w LOOK: Crawler must not mistrack.

IMPORTANT: Transmission oil temperature must NOTE: If mistrack is noted and considered excessive,
be at operating temperature (green mark down the pattern of mistrack and see
zone) for this check. Mistracking Complaints Diagnostic Flow Chart.

a. Operate engine at approximately 1500 rpm.

b. Pull tee handle up.
c. Make several direction changes forward to re-
verse and visa versa moving the FNR lever as
fast as possible and change speed by moving
the FNR quickly in forward and reverse.
d. Observe the rate of which the crawler changes Continued on next page
speed and direction.

LOOK: The crawler must slo w down, change direction,

and speed up again smoothly.

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 Operational Checkout Procedure/Hydras ta tic Crawler

ACTION: (Motor Phase Tracking Check) LOOK: Charge pressure must NOT drop in to red zone
a. Operate crawler on marked course with engine during this check.
at high idle.
b. Drive crawler forward with FNR lever at 2/3 FNR NOTE: It is difficult to load unit in reverse.
speed position in quadrant with Tee handle up.
c. When crawler has been aligned in course DO If charge pressure gauge indicates a drop
NOT touch any controls. during this check or mistrack occurs, see Lack
d. Observe how crawler tracks through marked Of Power or Cycling Complaints Diagnostic
course. Flow Chart.
e. Repeat procedure in reverse.
ACTION: (Injection Pump and Automatic Control Valve
LOOK: Crawler must not mistrack. Synchronication Chart.
a. Tee handle down.
NOTE: If mistrack is noted and considered excessive, b. Operate engine at approximately 1200 rpm.
mark down the pattern of mistrack and see c. Place hydraulic function over relief and hold
Mistracking Complaints Diagnostic Flow Chart function actuated for entire test.
d. Place FNR lever full forward.
ACTION: (Full Speed Tracking Check-Motor Stops) e. Gradually increase engine rpm to high idle then
a. Operate crawler on marked course with engine decrease engine rpm to approximately 1200
at high idle. rpm.
b. Drive crawler forward with FNR lever against the f. Observe track speed and sound of engine as
stop in the quadrant. engine speed is increased and decreased.
c. When crawler is aligned in course, DO NOT
touch any controls. LOOK AND LISTEN: The tracks must NOT stop and
d. Observe how crawler tracks through marked engine must NOT stall.
course.
e. Repeat procedure in reverse. NOTE: It is normal for the tracks to slow down as the
engine hand throttle reaches high idle position
LOOK Crawler must not mistrack. in the quadrant and speed up slightly as the
throttle is pulled back from the high idle
NOTE: If mistrack is noted and considered excessive, position. It is normal for the tracks to stop when
mark down the pattern of mistrack and see the hydraulics are over relief and operation with
Mistracking Complaints Diagnostic Flow Chart. the FNR at full forward with the hand throttle
at below approximately 1200 rpm position. If
ACTION: (Full Load Tracking Check) the tracks stop or engine stalls during this test
a. Operate unit at approximately 1500 rpm. see Injection Pump and Transmission Control
b. Tee handle down. Valve Synchronization, Procedure 27.
c. Use blade or bucket to load engine down in
forward.
d. Observe how units tracks under load.
e. Observe charge pressure.
f. Repeat procedure in reverse.

LOOK The unit must NOT mistrack.

Continuted on next page
NOTE: Mistrack could be caused by uneven load. If
constant correction in one direction is noticed
a difference in efficiency from side to side is
indicated.

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 Operational Checkout ProcedureIHydros ta tic Crawler

ACTION: (Automatic Control Valve Engine Lug Down- ACTION: Automatic Contol Valve Shut-off Linkage
P4 Check) Check
a. Tee handle down. a. Repeat above procedure for Automatic Control
b. Operate engine at high idle. Valve Engine Lug Down P4 Check.
c. FNR lever full forward position. b. Pull up on Tee handle and observe tracks
d. Counter rotate one track. and engine sound.
e. Operate hydraulic function over relief.
f. Observe tracks and note engine sound. LOOK AND LISTEN: The tracks must increase in
speed and engine must lug
LOOK Tracks will slow down but must NOT stop. down near stall.
Engine must NOT hunt or cycle.
NOTE: If tracks don’t increase in speed and engine
NOTE: If tracks stop or engine hunts or cycles during doesn’t lug down the automatic control valve
this check, see Lack Of Power or Cycling shutoff is malfunctioning. See Automa tic Con-
Complaints Diagnostic Flow Chart and Auto- trol Valve Shut-Off Cable Adjusment, Proce-
matic Control Valve P-4 Adjustment, Procedure dure 33.
23.

T59;9005 139 251083

7. Dozer Hydraulic System Check

NOTE: If these functions settle before moving the
NOTE: These checks must be done with the hytdraulic direction actuated check the control valve lift
oil temperature at about 120-F or when the check poppet. See Group 3260 for repair.
reservoir (left hand side) is uncomfortable to
continually touch. ACTION: (Blade Float)
a. Raise the front of the unit off the ground using
ACTION: (Control Valve Linkage Check) the blade lower function.
a. Move and release the control lever (levers) in all b. Move blade control lever to float position
positions.
LOOK Front of unit must lower to ground.
LOOK AND FEEL: Control lever must move back to
neutral freely and NOT have excessive free NOTE: Float connects head and rod end of cylinders.
Play.
ACTION: (Auxiliary Control Valve Lift Check With
L COK: Control valve must remain in the float position. Ripper)
a. Raise the rear of unit off the ground using the
ACTION: (Blade Control Valve Lift Check) ripper lower function.
a. Tilt the dozer blade to the right but not a full tilt b. Slowly move ripper lower function to raise unit
right. further off the ground.
b. Lift the front of unit off the ground using blade
lower function but not at full lower position. LOOK: The rear of unit must NOT drop before it raises
c. S lowly move the control lever to lower the blade, as the control valve is actuated.
then slowly tilt the blade to the right.
NOTE: See Group 3260 for repair.
LOOK: The front of the unit must NOT drop when the Continued on next page
blade lower or tilt right function is actuated.
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 Operational Checkout ProcedureIHydros ta tic Crawler

1
ACTION: (Auxiliary Control Valve Lift With 6505 All- ACTION: (Hydraulic Pump Gereral Performance
Hydraulic Dozer) Check)
a. Angle dozer to the right but not at full right a. Operate engine at slow idle.
position b. Raise blade from ground to maximum height and
b. Position unit with right corner of the blade record cycle time.
against a solid object.
c. Slowly angle the blade to the left. LOOK: Maximum cycle time for:
6505 All-Hydraulic Dozer . . . . . .5.5 seconds
LOOK: Blade must NOT angle right before it angles Angle Dozers and Bulldozer . . .6.5 seconds
left. 750 LGP Bulldozer . . . . . . . . . . .9.0 seconds
850 LGP Bulldozer . . . . . . . . . . .8.0 seconds
IMPORTANT: If unit is equipped with a 6505 (All-
hydraulic) dozer, ripper, and selec- NOTE: Take the average cycle time of 3 complete
tor valve, the function that is not cycles. The average cycle time will give a
selected does not have a circuit general indication of hydraulic pump perform-
relief valve. ance. For hydraulic pump test, see Group
9025.
ACTION: (Blade Lift Cylinder Poppet Check -6525,
6545 Bulldozer Only) ACTION: (Blade Drift)
a. Operate engine at slow idle. a. Position blade about 50 mm (2 in.) off the ground.
b. Tilt blade to maximum right then lift blade to b. Stop engine and wait for one minute.
maximum height.
c. Tilt blade to full left then back to full right position. LOOK Blade must NOT touch ground.
d. Lift blade to maximum height again.
NOTE: Use good judgement in determining if the
LOOK: Blade must move to maximum height again. amount of drift is objectionable for the type of
operation the unit is performing. For blade drift
NOTE: A check poppet in the lift cylinders allows oil test see Group 9025.
to be transfered from rod to head end when the
blade is at maximum height and tilted from full
right to full left. See group 3260 for repair.

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 Operational Checkout Procedure/Hydras ta tic Crawler

8. Loader Hydraulic System Check ACTION: (Boom Lower Circuit Relief Valve Test)
a. Crowd the bucket into a dirt pile.
NOTE: These checks must be done with hydraulic oil b. Roll back the bucket and watch boom
temperature at about 12O.F or when reservoir movement.
(left-hand side) is uncomfortable to continually
touch. LOOK Boom must NOT collapse.

ACTION: (Control Valve Linkage Check) NOTE: If boom collapses, the boom circuit relief
a. Move and release control lever (levers) in all is low, hydraulic system relief is set high, or
positions. cylinder leakage is indicated.

LOOK AND FEEL: Control lever must move back to ACTION: (Bucket Dump Circuit Relief Valve Check)
neutral freely and NOT have excessive free a. Position bucket at 45 angle to the ground.
Ph. b. Lift front of unit off the ground using boom lower
function.
LOOK: Control must remain in the float position. c. Operate unit in reverse (back-drag) and watch
bucket angle.
ACTION: (Loader Control Valve Lift Check)
a. Position bucket at about a 45 angle. LOOK: Bucket angle must NOT change.
b. Lift the front of the unit off the ground using the
boom lower function but not a full lower position. NOTE: If bucket collapses the bucket dump circuit
c. Slowly move control lever to lower boom, than relief is set low or cylinder leakage is indicated.
slowly move control lever to bucket dump
position. NOTE: It is normal for the clam function to open when
back-dragging.
LOOK: The front of the unit must NOT drop when the
boom lower or bucket dump function is ACTION: (Bucket Roll-Back Circuit Relief Valve Check)
actuated, a. Position bucket at 45 angle to the ground in front
of an immovable object.
NOTE: If these functions settle before moving the b. Starting with unit at ‘/2 fast idle, place unit in
direction actuated, check the control valve lift forward direction. Increase speed control lever
check poppet. See Group 3260 for repair. in forward until tracks begin to spin.

ACTION: (Boom Float) LOOK: Bucket angle must NOT change.

a. Raise front of unit off ground using boom lower
function. NOTE: If bucket collapses the bucket roll-back circuit
b. Move boom control lever to float position. relief is set low or cylinder leakage is indicated.
If bucket collapses both direction the problem
LOOK: Front of unit must lower to ground. is probably cylinder leakage.

NOTE: Float connects head and rod end of cylinders.

ACTION: (Auxiliary Control Valve Lift Check With

Ripper)
a. Raise the rear of unit off the ground using the
ripper lower function. Continued on next page
b. Slowly move ripper lower function to raise unit
further off the ground.

LOOK: The rear of unit must NOT drop before it raises

as the control valve is actuated.

NOTE: See Group 3260 for repair.

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 Operational Checkout Procedure/Hydrostatic Crawler

ACTION: (Hydraulic Pump General Performance

Check)
a. Operate engine at slow idle
b. Raise boom from ground, to maximum height
and record cycle time.

LOOK: Maximum cycle time must be less than 17

seconds.

NOTE: Take the average cycle time of 3 complete

cycles the average cycle time will give a
general indication of hydraulic pump petform-
ante. For hydraulic pump test, see Group
9025.

ACTION: (Boom and Bucket Drift)

a. Position bucket at 45 angle to the ground at
about 50 mm (2 in.) off the ground.
b. Stop engine and wait for 1 minute.

LOOK: Bucket teeth must NOT touch ground.

NOTE: Use goodjudgement in determing if the amount

of drift is o fjectionable for the type of operation
the unit is performing. For drift test see Group
9025.

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T76;9005
PI1090184
 Operational Checkout Procedure/Hydrostatic Crawler

9. Undercarriage Checks LOOK Maximum gap is 0.040 in. (thickness of dime).

NOTE These undercarriage checks should be used NOTE: If front idler vertical gap is excessive, the ability
only as a general indication of undercarriage to finish grade with the era wler is affected, also
condition. If any area is questioned refer to track adjustor wear will result.
Wndercarriage Appraisal Manual” for meas-
urement and analysis. ACTION: (Crossbar Clearance Check -Dozers Only)
a. With crawler on level ground, raise blade off the
NOTE: Undercarriage wear is accelerated by exces- ground.
sive high speed, reverse, and counter-rotate b. Stop engine and slowly lower blade to the
operations. ground.
c. Crawl under machine and check crossbar
ACTION; (Track Tention and Roller Leakage Check) clearance (at each end of bar between support
a. Inspect track sag and any indication of roller and top of bar, and between crossbar and center
leakage on both sides. retainer)

LOOK: Track tension must NOT be too tight or too LOOK: Maximum gap is 0.060 in. (thickness of quarter)
loose. at center and i/4 in. for a 750 LGP or 4/10 in.
for a 850 at the bar ends (the 750 is not shim
NOTE: If track tension is too tight, excessive fuel adjustable).
consuma tion and track wear will result. If track
tension is too loose, the tracks may cause NOTE: Crossbar gap will affect the ability to finish
chipping of roller flanges and chain rails, or the grade with the era wler, and therefore should be
track may come off crawler. kept to a minimum.

LOOK: Must NOT see any evidence of oil leaks from ACTION: (Track Pitch Check)
rollers. a. Check the position of the front edge of the front
idler guide block assembly to the front edge of
ACTION: (Grouser Wear, Bent Track Shoe, and Loose the wear strip.
Hardware Check)
a. Operate crawler at slow speed forward. LOOK If front edge of the front idler guide block
b. Check track pads as they run over the front idler. assembly is past the front edge of the wear
strip on a 655 or 750 or within 1 inch of the front
LOOK Check height of grouser, check for bent or edge of the wear strip on a 755A, 850, or 855
loose pads. indicates track pitch measurement should be
taken.
NOTE: Loose or mission hardware or thin grousers
could cause bent tracks pads. NOTE: Turning chain pins and bushings will correct
track pitch.
ACTION: (Track Chain Joint Flex Check)
a. Operate crawler at slow speed forward.
b. Check track chain as it runs over carrier roller.

LOOK: Track chain must roll freely over carrier roller.

Continued on next page
NOTE: lt is normal for a new lubricated track chain to
be %tiff” as it rolls over carrier roller until joint
“seating ” is established.

ACTION: (Front Idler Vertical Adjustment Check)

a. Position front idler on a block of wood or a pile
of dirt approximately 6 in. high.
b. Check the gap between the front idler guide
block assembly and wear strips.
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PU090184
 Operational Checkout Procedure/Hydrostatic Crawler

ACTION: (Pin Boss Wear) ACTION: (Lubricated Track Chain Seal Check).
a. Check pin boss for wear. a. Inspect the distance from the pin boss of one link
to the opening adjacent to the pin boss. Com-
LOOK: Pin boss wear indicates contact with rock pare this space for all links.
guides or roller flanges.
LOOK If a wider space is noticed a “dry” joint in the
LOOK: Excessive pin boss wear may also indicate pin lubricated track is indicated. This wider space
to bushing wear (snaking) or excessive side hill is caused by wear.
operation.
NOTE: Normally this “dry” joint cannot be relubricated
NOTE: Some pin boss end wear is normal but if wear because seal damage has occured. Measure-
is only excessive on one side, side hill oper- ment should be taken and wear monitored.
a tion in one direction may be indicated. This will be critical joint.

ACTION: (Sprocket Wear Check)

a. Operate crawler in forward then slowly
come to a stop.
b. Check sprocket for forward and reverse
drive and tooth tip wear.

LOOK: Reverse drive wearing more than forward is

normal from reverse operation.

NOTE: The sprockets can be changed from side to

side on the crawler for added life.

LOOK Reverse drive tip wear is caused by normal dirt

packing in the sprocket root in the forward
direction. If packing is a problem loosen track
tension.

NOTE: DO NOT judge the condition of the sprocket

by the appearance of tooth tip wear. Tip wear
does not affect the service life of the sprocket
because wear does not extend into the drive
area of the sprocket.

“Popping” of the track can occur in forward

and reverse. Popping in forward is caused by
material packing in the sprocket. Popping in
reverse is normal while operating under heavy
loads. The recoil spring is recoiling allowing
sprocket to “slip” in the chain, thus protecting
powertrain and track components.

ACTION:(Track Roller Check)

a. Have another person operate machine in
forward direction.

LOOK All rollers must turn but must NOT “wobble”.

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PI, 0901m
 Operational Checkout Procedures/Hydras ta tic Crawler

10. Accessories and Cab Components

(Engine Off-Key Switch On) ACTION: (Seat Belt)
a. Fasten seat belt and move belt tighteners.
ACTION: (Horn Button) b. Release seat belt.
a. Depress horn botton
LISTEN: Horn must sound. LOOK Seat belt must latch together and belt tighten-
ers must move freely. Seat belt must release
ACTION: (Light Switch) when bucket is lifted.
a. Pull out light switch.
ACTION: (Tool Box Door)
LOOK: Two front canopy lights must be on. The rear a. Unlatch tool box door (under seat).
work lights must be on.
LOOK: Door must open easily and relatch when
LOOK: The dash gauge back lights (5) must be on. closed.

LOOK: (If equipped with cab) Cabin light must be on. ACTION: (Starting Aid)
a. Start engine and run at slow idle with neutral lock
ACTION: (Cigar Lighter) lever in up position.
a. Depress cigar lighter. b. Depress start aid button for a few seconds.
c. Listen to engine rpm.
LOOK Cigar lighter must pop out and center must d. Stop engine
glow red.
LISTEN: Engine rpm must increase when start aid
ACTION: (Seat Fore-Aft Adjustment Check) button is pressed.
a. Lift seat fore-aft lever.
b. Move seat forward and rearward and release NOTE: If engine rpm does not increase, the problem
lever. could be start aid solenoid, start aid can
position, or empty start aid can.
LOOK: Lever must move freely and lock seat in
desired position, ACTION: (Cab Door Latch)
Unlatch cab door.
ACTION: (Seat Height Adjustment Check) b. Slowly close cab door.
a. Push seat “height” lever down and at the same
time remove your weight from the seat. LOOK Cab door must unlatch easily and latch in first
b. Raise seat to several positions and engage latch psoition when slowly closed. The door will
latch. have movement in this position.

LOOK Seat latch must move freely and hold seat at ACTION: (Cab Door Latch)
any desired position. a. Unlatch cab door.
b. Close door with force.
ACTION: (Seat Weight Adjustment)
a. Turn weight adjustment spinner. LOOK Cab door must latch in 2nd latch position and
no door movement must be felt.
LOOK: Spinner must turn.
NOTE: If force required to fully latch door is excessive
NOTE: While sitting in seat, turn weight adjustment door catch wear will result.
spinner until weight indicator is flush with tube.

ACTION: (Seat Tilt Lever) Continued on next page

a. Lift tilt lever and tilt entire seat forward.
b. Release lever and return seat to original position.

LOOK: Seat must be able to tilt forward to expose

batteries and tilt lever must latch seat down in
operating position.
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PM100184
 Operational Checkout Procedure/Hydrostatic Crawler

XTION: (Windshield Wiper/Washer) ACTION: (Air Conditioner)

a. Turn front windshield switch on. a. Turn off heater and operate air conditioner on
b. Push wiper/washer switch in. maximum cool position.

LOOK Front windshield must have two speeds and LISTEN: Engine rpm should decrease which indicates
washer solution must spray from washer jet compressor is operating.
when switch is pushed.
FEEL: Cool air should emit from dicharge duct (allow
ACTION: (Rear Windshield Wiper) enough time for air to cool).
a. Turn wear windshield wiper switch on.
LOOK: Air conditioner plugged condenser light must
LOOK Rear wiper must have one operating speed. NOT be on.

NOTE Rear wiper switch has two positions but only

one is used.

ACTION: (Side Window Latch)

a. Turn white window knob fully clockwise and
gently try to open window on each side.
b. Turn white window knob counter-clockwise and
try to open window on each side.

LOOK: Side windowmustnotopen when windowlatch

is fully clockwise, but must open when window
latch is counter-clockwise.

ACTION: (Dome light)

a. Switch ligh on.

LOOK: Dome light must come on.

ACTION: (Cab Heater/Air Conditioner Blower Check)

a. Turn blower switch to all positions.

FEEL: Blower must have three speeds.

ACTION: (Heater)
a. Operate engine for at least five minutes.
b. Turn heater control knob clockwise to maximum.

NOTE Air conditioner control off Also water shut-off

must be open on engine water pump.

FEEL: Heat must emit from discharge duct.

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T76;9005
PI5100184
 Operational Checkout ProcedurelHydrosta tic Crawer

Litho in U.S.A. 9005-l 6 SP-579, TM-1 136, 1137, 1164, 1165, 1231, 1250
T78;9005
Plb190184
JD750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Feb-77) Engine 901 o-1

Group 9010
ENGINE
GENERAL INFORMATION

The crawler uses a 414 cu. in. (6 785 cm3) diesel- Fuel System
fueled, valve-in-head, vertical in-line six-cylinder en-
The components of the fuel system are the fuel tank,
gine.
fuel transfer pump, fuel filter, fuel injection pump and
the fuel injection nozzles.
Engine Lubrication System
The components of the lubrication system are the oil The fuel supply pump operates off a cam lobe of the
pump, oil cooler, oil filters, and oil pressure regulating camshaft. It draws fuel from the tank and delivers it to
valve. the fuel injection pump through the fuel filter.

The oil pump draws lubricant from the oil pan The injection pump pressurizes the fuel and sends it
through a system of gears and sends it through an through high-pressure lines to the injection nozzles.
internal passage through the oil cooler.
The injection nozzles open when the fuel reaches a
As the oil moves through the cooler, the oil temper- specified pressure and inject the fuel into the combus-
ature is lowered by coolant flow. If the cooler becomes tion chambers.
restricted, the cooler bypass valve routes oil directly to
the oil filters. Air Intake System
The components of the air intake system are the air
The oil pressure regulating valve is used to maintain
cleaner, turbocharger and intake manifold.
and regulate oil pressure. From the regulating valve
the oil goes to the oil filters.
The air enters through the air cleaner. The air
cleaner element removes impurities from the air. The
The oil filters are spin-on replaceable elements. The
air cleaner has a restriction indicator switch accessible
filters remove contaminants from the engine oil. From
through the service opening in the hood. The switch
the filter the oil goes to the gallery and is dispersed to
warns the operator of excessive restriction in the sys-
lubricate the internal moving parts of the engine and
tem.
the turbocharger.
The turbocharger receives air from the air cleaner,
Engine Cooling System
pressurizes it and sends it through the intake manifold
The components of the cooling system are the radi- to the combustion chambers. During engine operation,
ator, water pump and fan. exhaust gases enter the turbine housing of the tur-
bocharger rotating the turbine wheel and compressor.
The radiator is equipped with a pressure cap which The compressor draws in and compresses air. As
acts as a relief valve to keep pressure at a specified engine fuel delivery increases, the flow of exhaust
level in the system. gases increases, and the speed of the rotating as-
sembly increases; thus the amount of air entering the
The water pump draws coolant from the radiator and intake manifold increases.
sends it into the coolant gallery and engine oil cooler.
Coolant from the gallery circulates through the engine Speed Control Linkage
to cool the block, cylinder liners, and head, and then
The speed control linkage consists of various link-
flows into the water manifold. Coolant for the oil cooler
ages which are connected to the injection pump.
flows from the cylinder block to cooler and then returns
Through common movement of the throttle and link-
to the inlet side of the water pump.
age, speed control is maintained. Any repair or adjust-
ment of the engine speed control linkage requires
re-synchronization of engine speed with the transmis-
sion automatic control valve. See Group 9026.

Litho in U.S.A.
90 System Testing JO750 Crawler Bulldozer
901 o-2 Engine TM- 1136 (Feb- 77)

l-Bayonet Fuel Gauge

2-Fuel Strainer
3-Cold Weather Starting Aid
4-Fuel Tank
!+Engine Ventilator Tubs
6-Pre-Cleaner
7-Turbocharger Oil Inlet Line
S-Air Cleaner
g--Muffler
l&-Engine Oil Dipstick
1 l-Engine Oil Filler
124Iadiator
13-Crankshaft Dampener
14-Fan Belt Tensioner
15-Engine Oil Cooler
M-Fuel Transfer Pump
fir-Engine Oil Filters
t&Fuel Inlet Line
lg-Intake Manifold
~CI--Fuel Filter
Pl-Flywheel
22-Fuel Return Line
23-Drain Cock
24-Fuel Shut-Off Valve

Legend for Fig. 1-Componenf Location - Engine

23-Fan Guard
26Fan
27-Thermostat Housing
P&Injection Pump Leak-Off Line
Pg-Turbocharger
3&-Exhaust Manifold
Jl-Turbocharger Oil Outlet Line
32-Speed Control Linkage
33-Engine Speed Control Lever
34-Fuel Line to Injection Pump
33--Fuel Injection Noule
36-Fuel Injection Line to Nozzle
37-Fuel Injection Pump

Legend for Fig, IA-Component Location _ Engine

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Nov-75) Engine 90104

DIAGNOSING MALFUNCTIONS

Engine Will Not Start or Starting Hard Engine Misses

Fuel System Malfunction Basic Engine Malfunction
Fuel tank empty Weak valve springs
Improper type of fuel Incorrect valve clearance
Foreign material in fuel Burned, warped, pitted or sticking valves
Fuel lines clogged or restricted Low compression
Air leak on suction side of fuel system Worn camshaft lobes
Fuel transfer pump failure Engine overheating
Fuel filter restricted Fuel System Malfunction
Restricted air intake system Water, air or dirt in fuel
Faulty injection pump Faulty injection nozzles
Faulty injection nozzles Faulty injection pump
Water, dirt, or air in fuel system Faulty transfer pump
Electrical System Malfunction Detonation
Corroded or loose battery cables Mixture of gasoline and diesel fuels
Weak or dead battery
Cranking speed too slow Lack of Power
Basic Engine Malfunction
Uneven Running or Frequent Stalling Blown cylinder head gasket
Basic Engine Malfunction Worn camshaft lobes
Improper valve clearance Incorrect valve clearance
Cylinder head gasket leaking Incorrect valve timing “’
Valves sticking or burned Burned, warped, pitted, or sticking valves I
Worn or broken compression rings Weak valve springs
Low compression Low compression
Incorrect timing Dirty air intake system
Dirty air intake system incorrect timing
Exhaust system restricted Engine overheating
Engine overheating Fuel System Malfunction
Fuel System Malfunction improper type of fuel
Improper type of fuel Air leak on suction side of fuel system
Air leak on suction side of fuel system Fuel line clogged or restricted
Fuel line clogged or restricted Fuel transfer pump failure
Fuel transfer pump failure Speed control linkage not adjusted properly
Fuel filter restricted Fuel filter restricted
Faulty injection pump Fuel injection pump failure
Faulty injection nozzles Fuel injection nozzle faulty
Water, dirt, or air in fuel system Water, dirt or air in fuel system
Injection nozzle leak-off lines clogged Injection nozzle leak-off line clogged
Injection pump out of time Injection pump out of time
Exhaust system restricted Clogged manifold system
Linkage Malfunction Linkage Malfunction
Linkage faulty Linkage faulty
Linkage not synchronized with Linkage not synchronized with
transmission control valve transmission control valve

Litho in U.S.A.
 90 System Testing JD750 Crawler Bulldozer
9010-6 Engine TM- 1136 (Nov- 75)

Black or Gray Exhaust Smoke Abnormal Engine Noise

Basic Engine Malfunction Basic Engine Malfunction
Incorrect engine timing Excessive valve clearance
Engine overloaded Worn cam followers
Restricted air cleaner Bent push rods
Defective muffler Worn rocker arm shafts
Dirty air intake system Worn main or connecting rod bearings
Fuel System Malfunction Foreign material in combustion chamber
Improper grade of fuel Worn piston pin bushings and pins
Excessive fuel delivery Scored piston
Faulty injection nozzles Incorrect engine timing
Injection nozzle leak-off line clogged Excessive crankshaft endplay
Injection pump out of time Loose main bearing caps
Worn timing gears
White Exhaust Smoke Worn oil pump gears
Broken oil pump shaft
Basic Engine Malfunction
Low engine oil level
Low compression

q
Camshaft oil pump gear worn or broken
‘I Fuel System Malfunction
Gears worn or broken
Faulty injection nozzle
Turbocharger bearing failure
,, Improper fuel
Injection pump out of time
Excessive Oil Consumption
Slow Acceleration Basic Engine Malfunction
Restricted crankcase breather
Fuel System Malfunction
Worn valve guides or valve stems
Faulty injection nozzle
Piston rings worn or broken
Improper fuel
Scored lines or pistons
Excessive ring groove wear in piston
Detonation
Rings sticking in grooves of piston
Fuel System Malfunction Oil return slots in piston clogged
Injection pump out of time Insufficient piston ring tension
Faulty injection nozzles Piston ring gaps not staggered
Excessive main or connecting rod bearing clear-
ance
Worn crankshaft thrust bearing (misaligned piston
and rod)
Front or rear crankshaft seal faulty
Crankcase oil too thin (wrong viscosity)
Oil level too high
Restricted air intake system

Litho in U.S.A.
JD750 Crawler Bulldozer Sys tern Tes tint 90
TM-1 136 (Feb-77) Engine 9010-7

Low Oil Pressure Water Pump Leaks

Basic Engine Problem Basic Engine Malfunction
Excessive main and connecting rod bearing Worn seal and/or shaft in water pump
clearance Worn or broken water pump gasket
Low oil level Water pump damaged
Leakage at internal oil passages Water pump impeller broken
Faulty oil pump
Improper regulating valve operation Engine Runs Cold
Improper oil (wrong viscosity)
Basic Engine Problem
Defective oil pressure indicator light
Faulty thermostat
Defective temperature gauge
High Oil Pressure
Basic Engine Problem Water Pump Making Noise
Stuck regulating valve
Basic Engine Malfunction
Regulating valve spring worn or broken
Worn water pump shaft
Water pump impeller broken
Engine Overheats
Bent or broken fan blade
Basic Engine Malfunction Loose fan belt
Defective head gasket Fan hitting
Incorrect engine timing
Low coolant level Oil in Coolant or Coolant in Crankcase
Radiator dirty or plugged
Basic Engine Malfunction
Loose or broken fan belt
Leaking head gasket
Faulty thermostat
Cylinder liner packings leaking
Cooling system limed up
Cylinder block water jacket cracked
Defective radiator pressure cap
Cylinder liner cracked
Faulty water pump
Faulty engine oil cooler
Scored piston
Air in coolant
Engine overloaded
Crankcase oil level low
Fuel System Malfunction
Improper fuel
Excessive fuel delivery
Improper injection pump timing

Litho in U.S.A.
 90 Sys tern Testing JD 750 Crawler Bulldozer
901 O-8 Engine TM- 1136 (Feb-77)

VISUAL INSPECTION

By visually inspecting the engine before you tune it, Alternator and Fan Belts
you can learn much about its general condition.
The alternator and fan belts should be neither too
tight nor too loose.
For example, if the engine has been using too much
oil, this often means an external leak. If the engine
A belt which is too tight puts extra load on the
overheats, look for leaks in the cooling system.
bearings and shortens the life of the bearings as well
as the belts. A belt which is too loose allows slippage
Oil and Water Leakage and lowers the speed, causes excess belt wear and
Look for water leaks at the radiator, water pump and leads to cverheating of the cooling system.
hoses around the cylinder head gasket and water
manifold. The condition of the belts and their tension should
be checked periodically. Adjust belt tensions as shown
Check coolant for proper level and examine visible in testing and adjustment in this group.
portion inside top of radiator for evidence of rust or
Fuel Tank

q’
I
scale.
Check all seams and connections for fuel leakage.
Check crankcase oil level and for coolant in oil.
Fuel Transfer Pump
Look for oil leaks at the oil pan, drain plugs and
gaskets. Check fuel inlet and outlet connections for leaking
fuel. Be sure primer lever is as far down as possible.
Hoses
Fuel Injection Pump
Inspect upper and lower radiator hoses and bypass
hose for hardening or cracking, and softening and
swelling. Examine hoses at least twice a year for
possible replacement and tightening.
A CAUTION: Escaping diesel fuel under
pressure can have sufficient force to pen-
etrate the skin causing serious personal injury.
Fuel escaping from a very small opening can be
Oil Cooler almost invisible. Use a piece of cardboard or wood,
Check top and bottom covers and oil filter housing to rather than a hand to hold near connections to
cooler connection for oil leakage. Check water inlet check for fuel leaks.
and outlet for leakage. If injured by escaping fuel, see a doctor at once.
Serious infection or reaction can develop if proper
Radiator medical treatment is not administered at once.

Inspect the radiator for bent fins, kinks, dents and

Check fuel inlet and outlet connections and high
fractured seams, and tubes for cracks. Check radiator
pressure fuel supply connections. If any of the lines are
mounts for wear, cracking and loose mount hardware.
twisted, kinked or broken, repair or replace as neces-
sary.
Fan
The only service possible on the fan is to be certain
the fan blades are straight and are far enough from the
radiator so they do not strike the core.

Bent blades reduce the efficiency of the cooling

system and throw the fan out of balance.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Engine 9010-g

Fuel Filter Air Cleaner

Check fuel inlet and outlet connections. Check ele- Check all air intake and outlet connections to be
ment cover daily for deposits. Clean if necessary. sure they are tight. Check air restriction indicator daily.
Replace filter element as required. Clean element when indicator shows red with engine
shut off, or when excessive smoke or loss of power is
Fuel Injection Nozzles noted.

A CAUTION: Escaping diesel fuel under

pressure can have sufficient force to pen-
Check air hoses for deterioration.

etrate the skin causing serious personal injury. Replace air cleaner elements every 1000 hours.
Fuel escaping from a very small opening can be
almost invisible. Use a piece of cardboard or wood, Turbocharger
rather than a hand, to hold near connections to
Check all air inlet and outlet connections and all
check for fuel leaks.
manifold and turbocharger gaskets. Be sure oil inlet
If injured by escaping fuel, see a doctor at once.
and drain lines are not twisted, kinked, or broken.
Serious infection or reaction can develop if proper
Replace or repair as necessary.
medical treatment is not administered at once.
Be sure there is no strain on the connector between , ,
Check each de!ivery and leak-off line. Repair or
the turbocharger and intake manifold. m
replace lines if necessary.

Speed Control Linkage

Check the speed control linkage to insure there are
no bent or inoperable links or cable. Check to insure
that when the injection pump lever contacts the high
idle stop on the injection pump, the automatic control
valve variable orifice lever contacts the high idle stop
on the transmission control valve. Refer to Procedure
4, adjustment section, Group 9026 for this adjustment.

Litho in U.S.A.
90 System Testing JD7.50 Crawler Bulldozer
9010-l 0 Engine TM- 1136 (Apr- 79)

TESTING AND ADJUSTMENT

Basic Engine Engine Lubrication System

Compression Pressure Test Checking Engine Oil Pressure

Engine oil pressure should be checked before and
1 - Clean the engine thoroughly, preferably by steam
after a major overhaul or anytime it is necessary to
cleaning.
remove the oil pump.

2 _ Warm the engine to operating temperature.

3 - When engine has reached operating temperature,

turn ignition switch off.

Disconnect the electrical solenoid shut-off wire from

the injection pump. This will keep the injection pump
from pumping fuel under high pressure to the nozzles
during the test.

A CAUTION: The above step is important

because fuel under high pressure from the
injection pump will have sufficient force to pene-
trate skin. Do not, at any time, while the engine is
cranking, place hands or arms in front of the in-
jection nozzles. Fig. 2-Oil Pressure Test Connection Point

Remove all six injection nozzles and seal gaskets To check oil pressure, connect an oil pressure
from the head (see Section 4). gauge at area shown in Fig. 2.

Clean the injection bores. Blow loose carbon out With engine at normal operating temperature and
with compressed air. running at fast idle (2300 to 2320 rpm) (with cold
weather disconnect clutch disengaged), oil pressure
Install a 70-314 Compression Gauge Adapter in reading should be 50 r 15 psi (3 i: 1 bar) (3 rt 1
bore to be tested. A new seal gasket should be insert- kg/cm2).
ed before the adapter is installed.
Engine Output Check
Connect a 70-7003 Compression Gauge to the
adapter. Using the hydraulic analyzer, it is possible to check
the engine output (hp) (kW) for this crawler. Refer to
Diagnosing Failures section, Group 9026, Procedure
Crank engine at approximately 200 rpm with the
1.
starting motor.

Observe the pressure reading on the compression

gauge. The reading should be 300 psi (21 bar) (21
kg/cm”).

The most important factor in compression readings

is the difference between cylinders. This difference
should be no more than 50 psi (3 bar) (4 kg/cm*).

Litho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Engine 9010-l 1

I
If engine oil pressure is not 50 ? 15 psi (3 i: 1 bar) Engine Cooling System
(3 t 1 kg/cm2), the pressure regulating valve should
Since efficient operation of pressure cooling de-
be checked.
pends on a system that is free from leaks, the entire
cooling system should be tested prior to servicing.

Checking Radiator for Leaks

Install a pressure tester on the radiator according to

the manufacturer’s instructions.

T449978

Fig. 3-Oil Pressure Regulating Valve

Remove valve and check as described in Group

0407.

Install valve and recheck oil pressure. If pressure is

1 still not within 50 2 15 psi (3 t 1 bar) (3 + 1 kg/cm*),
other problems in the lubrication system are indicated .a

(see “Diagnosing Malfunctions” in this group).

Fig. 4-Testing Radiator

With the tester installed, carefully inspect the radia-

tor, water pump, hoses, drain cocks and cylinder block
for leakage.

Mark all leaks plainly to help locate them when

repairing.

If you cannot find any leaks but leaking persists,

remove the radiator and test as described in Group
0510.

q
For additional information on testing and
F@s maintaining the cooling system refer to
“Cooling System” in FOS Manual - Engines.
Q

Litho in U.S.A.
 90 System Testing JD750 Crawler Bulldozer
9010-12 Engine TM- 1136 (Apr- 79)

Alternator and Fan Belts Adjustments Fuel System

A CAUTION: Live sparks, smoking or fire of

any nature should not be permitted when
testing the fuel system.

Fuel Transfer Pump Pressure Test

Tee a low-pressure gauge (0 to 30 psi) (0 to 2 bar

minimum) (0 to 2 kg/cm* minimum) between the fuel
supply pump and fuel line to fuel filter.

Fig. 5-Belt Adjustments

NOTE: Use the JDST-28 Belt Tension Gauge for

more consistent be/t tension and longer belt life.

If a belt gauge measuring strand tension is used, the

initial reading should be 135 5 5 Ibs. (600 -r- 22 N) (61
2 2 kg) strand tension for a new belt. After ten minutes
of operation, recheck the belt tension. Gauge should
read 90 i 5 Ibs. (400 & 22 N) (41 + 2 kg) strand
tension.

IMPORTANT: Do not pry on the alternator rear

housing as this may damage the alternator.

To adjust the fan belts tension, loosen the two cap Fig. d-Fuel Transfer Pump Pressure
screws holding the idler pulley support onto the idler Test Connection Point
pulley bracket.
Start the engine. Let it run at low idle and observe
Turn the cap screw on the side of the idler pulley the low pressure gauge. Reading on the gauge should
support clockwise. This applies outward pressure on be2 to 2.5 psi (0.14to 0.17 bar) (0.14 to 0.17 kg/cm2).
the idler pulley. Tighten the two cap screws holding the
idler pulley support onto the idler pulley bracket. Remove pressure gauge and connect fuel line to
supply pump after test has been completed.
Apply approximately 25 pounds (111 N) (11 kg) of
force on the belts with a thumb midway between the
pulleys. Belt deflection should be 518 inch (16 mm).

If a belt gauge measuring strand tension is used, the

initial reading should be 100 c 5 Ibs. (445 r: 22 N) (45
t 2 kg) strand tension for a new belt. After ten minutes
of operation, recheck the belt tension. Gauge should
: read a minimum of 90 i- 5 Ibs. (400 -c 22 N) (41 c 2
kg) strand tension on front belt only.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Engine 9010-13

Adjusting Injection Pump Cam Advance 3 - Bring engine to operating temperature.

1 - Be sure injection pump is static timed to engine
4 - Check cam advance according to following
(see Group 0413).
specifications:

2 - Remove timing hole cover and install timing

DM4627MD2916
window (19918).
Total advance movement.. . . . .6” t l/2”
Advance at 600 to 1000 rpm (no load) 1”
Note the location of the cam timing line. Due to slight
variations in windows and hole locations, cam line may
NOTE: Marks on timing window are two pump de-
not be exactly behind window line. Adjust timing win-
grees apart.
dow to get best possible line up.

5 - If cam advance must be adjusted loosen lock

nut and turn advance trimmer screw.

Turn screw in (clockwise) to retard timing: turn screw

out (counterclockwise) to advance timing.

6 - Secure trimmer screw with lock nut and install e1

seal cap. R

7 - Remove timing window and install timing hole

cover.

Fig. 7-Cam Advance Trimmer Screw

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9010-14 Engine TM- 1136 (Apr- 79)

Speed Control Linkage

n P 1

l-Speed Control Lever 3-Lever 5-Fast idle Stop Screw

2-Engine Speed Cable 4-530~ Idle Screw 64njection Pump

Fig. B-Speed Control linkage

Speed Control Adjustment Adjust slow idle screw (4) on top cover for 975 to
1000 rpm and hold with jam nut. Adjust injection pump 1
NOTE: When adjustments are made, the cold
lever override mechanism so the slow idle screw on the
weather clutch should be disengaged (drive lines
override strikes its stop at the same time that slow idle
should not rotate).
is achieved by the adjustment at the top cover.

Set the fast idle on the fuel injection pump to 2300 to

Also refer to Procedure 19, adjustment section,
2320 rpm by turning the high idle stop screw (5, Fig. 8).
group 9026.
Turn out to increase speed.
IMPORTANT: Whenever either the high or low
Seal high idle screw.
idle speeds are adjusted on the injection pump, the
engine speed control lever to injection pump cable
adjustment has to be made. Refer to Engine Speed
and Transmission Control Valve Synchronization,
Procedure 4, adjustment section Group 9026.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Engine 9010-15

Air Intake System Engine Output Check

Testing Air Restriction Indicator Turbocharger Boost Pressure Test

See Group 9026 Diagnostic Procedure 1.

Fig. i&Air Restriction hdicator

Remove air restriction indicator (Fig. 10).

install a restriction indicator tee fitting into opening.

Install restriction indicator on one end of tee, add
D-05022ST water vacuum gauge on other end.

Start the engine and slowly cover air intake pipe.

Observe reading on water vacuum gauge. Restric-

tion indicator should show red when water vacuum
gauge reads 22.5 to 25.5 in. (56.0 to 63.5 mbar) of
water.

Remove water vacuum gauge, restriction indicator

and tee fitting. Install indicator.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9010-l 6 Engine TM- 1136 (Apr- 79)

Litho in U.S.A.
JD750 Cra wier Bulldozer System Testing 90
TM- 1136 (Mar-78) Electrical System 9015-l

Group 9015
ELECTRICAL SYSTEM
GENERAL INFORMATION A 24-volt negative grounded system is used for
electrically-operated components of this unit. Current
Component Location . ... 9015-3 is supplied by two 12-volt batteries connected in
Wire Terminal Location. . . : :iiGi 901513 series.
Testing
Starting Circuit .. . . . 901520 to 9015-25 The electrical system is a combination of three
Charging Circuit. . . 9015-26 to 9015-31 electrical circuits: the charging circuit, the starting cir-
Lighting Circuit . . 9015-31 to 901532 cuit and the accessory circuit. The accessory circuit
Instruments and Indicators 9015-32 to 9015-33 can be divided into the instruments and indicators
Miscellaneous Accessories 9015-34 to 9015-36 circuit, the lighting circuit and the miscellaneous ac-
Complete Electrical Schematic 9015-37 to 9015-40 cessory circuit.

This group contains troubleshooting tips, wiring dia- COMPONENT LOCATION

grams and test specifications necessary to locate
To aid in the identification and location of parts
problems in the system. By following the tests as given,
connected with the electrical system, the component
the defective component may be found and removed
location has a list of parts and illustrations, including
for more testing, repair, or replacement.
main wiring harness, circuit breakers and other elec-
trical system components.
Test and service instructions for system compo-
nents, when removed from the unit, are given in the
section including that specific component.

Litho in U. S.A.
/
90 Sys tern Testing JD750 Crawler Bulldozer
9015-2 Electrical System TM- 1136 (Mar-78)

I-Transmission Oil Filter Senders 26Alternator and Regulator

2-Ftuid Starting Aid 27-Fuel Injection Pump
3-Bear Windshield Wiper Motor 23-Air Conditioner Compressor Ground Lead
4-Bear Wiper Wire and Fuse 29-Air Conditioner Compressor Lead
%-Rear Work Light 3O-Air Conditioner Compressor
C’b Feed To Fuses Harness Il-Transmission Oil Pressure Switch
7-Dome Light Fuse Holder 32-Equipment Hydraulic Oil Pressure Switch
S-Equipment Hydraulic Oil Filter Sender 33-Starting Circuit Relay
%-Air Conditioner Fuse Holder 34-Starting Motor
l@-Air Conditioner ‘Thermostat Switch 3!%-Engine Harness
11-Rear Wiper Lead 36-Gab Relay To Cab Circuit Breaker Lead
12-Blower Switch to Thermostat Switch Lead 37-L.H. Instrument Panel Harness
13-Biower Motor Switch 3&-R.H. Instrument Panel Harness
14-Starter Safety Switch to Ground Lead 39-Light Harness
15-Starter Safety Switch 40-Rear Harness
1Come Light Lead 41-Battery To Starter Cable
17-Dome Light 42-Battery To Battery Cable
lS-Cab 30-Ampere Circuit Breaker 43-Battery Disconnect Switch
M-Front Work Lights 44-Batteries
2tI-Front Windshield Wiper Motor 4!5-Battery Ground Strap
21-tnstrument Panel (see Fig. 2A) 46-Battery Disconnect Switch Cable
22-Gab Relay 47-Gab Harness
23-Horn Ground Lead 43-Gab Blower Assemblies
24-Horn 4e-Cab Blower Harness
2!5-Horn Lead

Legend For Fig. l-Electrical System

2lA-Transmission Oil Pressure Gauge 21 K-Voltmeter

21 B-Transmission Oil Filter Indicator Light 21 L-Windshield Wiper and Washer Switch
21C-Cigar Lighter Resistor 21M-Windshield Wiper and Washer Lead with Fuse
21D-Transmission Oil Temperature Gauge 21 N-Starter Switch
21 E-Light 15Ampere Circuit Breaker 210-Ignition Key Switch
21F-Engine Oil Pressure Gauge 21 P-Cigar Lighter
21G-Horn Switch 21Q-Cigar Lighter To Resistor Lead
21 H-Equipment Hydraulic Oil Filter Indicator Light HR-Light Switch
211 -Main 30-Ampere Circuit Breaker 21S-Fluid Starting Aid Switch
21 J -Engine Coolant Temperature Gauge 21 T-Hour Meter

List of Parts For Fig. IA-Electrical Sysfem

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q Crawler Bulldozer Sys fern Testing 90
TM- 1136 (Mar-781 Electrical System 9015-S

Block Diagram (Fig. 2 or 3) A block diagram will not separate a problem to a

specific component, but it will make it easier most of
A block diagram is an easy-to-understand drawing
the time to separate a problem to one specific circuit.
of the power flow in the electrical system. It gives an
easy-to-follow description of the system circuits and
An example of how the block diagram can be used in
their relation to electrical components.
troubleshooting to rapidly separate the problem to a
specific circuit follows:
Use the block diagram (Fig. 2 or 3) to follow the
basic power distribution to the different circuits.
Problem: Cigar lighter works, but lights do not.

Starting at the batteries, trace a line to the starting

Solution: By turning to the block diagram, we can see
motor, to the circuit breaker and to the “BAT” terminal
the cigar lighter and lights are on the same
on the key switch.
circuit. The problem then is the light circuit
breaker, light switch or wiring.
The key switch has two output circuits: Accessory
(ACC) and Ignition (IGN).

The circuits can be understood very easily by fol-

lowing the connecting lines.

\/
” I GN”
KEY "ACC"
SWITCH

NDERS

START
IL SWITCH

i LIGHT
L I c-t
1 I CIRCUIT f- L1GHT I I
AIN SWITCH
' BREAKER GAUGE

J
ALTER- ' CIGAR CRAWLER
IRCUIT
NATOR LIGHTER BACK LIGHTS
REAKER
AND RESISTOR LIGHTS
REGULATOR
I 1 HYDRAULIC 1

STARTER
AND SOLENOID AIR BLOWER 'AIR
ITIONER- MOTOR -,CONDITIONER
SWITCH THERMOSTAT
- CAB
-x
I 5
LIGHT BLOWER BLOWER
FUSE _ MOTOR MOTOR
BATTERIES

'
T57590N --

Fig. P-Electrical Block Diagram (

Litho in U.S.A.
 90 Sysfem Testing JD750 Crawler Bulldozer
9015-6 Electrical System TM- 1136 (Mar-78)

r-l
FRONT
WIPER
MOTOR

KEY I I
"ACC" -
SWITCH
-,,BAi,tI
nIGNu
J
I
FUEL INJ.
PUMP / I
TEST TRANSMISSION
PRESSURE
SWITCH

1 BREAKER 1 L-7-J -I- i INDICATOR I\ I r.,-rn I I,,,,/ I I r..‘,, 1

NDITIONING
mmRCUIT
BREAKER
CONDITIONING
BLOWER
MOTOR
L THERMOSTAT

-I
I’ I- ITI

1 CIIDFP
, z;;;,H,,-*UFPT I
,
Fig. 3-Electrical Block Diagram (xxxxx- )

Schematic Diagram On the electrical schematic, the electrical current is

flowing from the positive (+) circuits and components
The complete electrical schematic diagram will be
to ground, and from ground back to the negative (-)
1 found in Fig. 25 and 26. It is given in the Technical
terminal of the battery.
Manual so that it can be folded out and referred to with
the specific section of the book on which you are
Many times an electrical problem can be solved by
working.
reasoning, using the schematic diagram and a min-
imum of testing. Upon finding an electrical problem,
The schematic diagram is a detailed “How it Works”
check it to find exactly what is not working correctly.
drawing of the electrical system. It gives the principles
Look at the schematic to find out if there are any other
of operation in a way that is easy to understand. The
components on that circuit that do work.
schematic can be used to troubleshoot and to connect
the problem with a specific component.
An example of using the schematic (Fig. 25 or 26) to
correct a problem follows:
To use a schematic diagram, it is necessary that you
know and understand the basic symbols used in an
Problem: Cigar lighter works, but lights do not. A volt-
electrical schematic.
age test taken at the light switch shows
voltage on only one terminal of the switch
For an explanation of basic symbols of an
with the switch on.
F@s electrical schematic, look at FOS Manual -
“ELECTRICAL SYSTEMS,” page IV.
a Solution: Defective light switch.
0

Litho in U.S.A.
JD 750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Mar-78) Electrical System 9015-7

42M

TRANSMISSION OIL
TEMPERATURE GAUGE
cT42L
D3G
TRANSMISSION OIL
PRESSURE GAUGE HOUR METER
120

i!z!
CIGAR LIGHTER AND
RESISTOR

,,,y--m .-j--42 32 13H

e-
LIGHT CIRCUIT
BREAKER LIGHT SWITCH TRANSMISSION OIL
FILTER LIGHT

135 2%.
3D-+7+66B
a-- 32 12c
STARTING 0 0 RIGHT INSTRUMENT PANEL
AID SWITCH --fk 28 TO CAB HARNESS CONNECTOR
RED
RIGHT INSTRUMENT PANEL
TO MtIN ENGINE HARNESS
CONNECTOR

T44207N

Fig. 4-Wire Terminal Location (Part I) ( -xXxXx) *

No. Color Routing No. Color Routing

3D Black Right instrument panel har- 28 Light Blue Starting aid switch to right in-
ness/main harness connector strument panel harness/main
to right instrument panel har- harness connector.
ness/cab relay harness con- 32 Yellow Transmission oil filter light to
nector. right instrument panel/main
12c Purple Light circuit breaker to right in- harness connector.
strument panel harness/main 42L Dark Blue Transmission oil pressure
harness connector. gauge to splice in 42A.
12D Purple Light circuit breaker to lighter 42M Dark Blue Transmission oil temperature
resistor. gauge to splice in 42A.
12E Purple Light circuit breaker to light 66B Yellow Right instrument panel har-
switch. ness/main harness connector
13F Orange Splice at 13G, 13H, 13J and to to right instrument panel har-
right instrument panel har- ness/cab harness connector.
ness/main harness connector.
I
13G Orange Hour meter to splice in 13F.
*Note: After xxxxx, See fig. 27. I
13H Orange Transmission oil filter light to
splice in 13F.
13J Orange Starting aid switch to splice in
13F.
Litho in U.S.A.
90 Sys tern Testing JD750 Crawfer Bulldozer
9015-8 Electrical System TM- 1136 (Mar-78)

12A

1 1A

STARTING MOTOR ;;jl;;ING CIRCUIT ALTERNATOR AND HORN

AND SOLENOID REGULATOR

13E

FUEL INJECTION AIR CONDITIONER OIL PRESSURE SWITCHES

PUMP COMPRESSOR

LIGHTS MAIN ENGINE HARNESS BLACK-LEFT RED-RIGHT

TO REAR HARNESS
CONNECTOR MAIN ENGINE HARNESS TO INSTRUMENT
PANEL HARNESS CONNECTORS

42H--I---42K 66C------I------66D f+----I-I-------64B

LIGHT CONNECTOR COMPRESSOR CONNECTOR HORN CONNECTOR

l'57592N

Fig. 5-Wire Terminal Location (Part 11)( -xXxXx) *

*Note: After xxxxx, See Fig. 27.

bitho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Mar-78) Electrical System 9015-g

The following is an explanation of Fig. 5-Wire Ter-

I No. Color Routing
minal Location (Part II).
218 White Starting motor “S” terminal to
No. Routing starting circuit relay.
1 Red Starting motor “Bat” terminal to 26A Light Blue Main harness/right instrument
starting circuit relay. panel harness connector to
1A Red Starting motor “Bat” terminal to main harness/rear harness
alternator output terminal. connector.
lB Red Alternator output terminal to al- 32A Yellow Main harness/right instrument
ternator No. 2 terminal. panel harness connector to
1c Red Main harness/left instrument splice at 328 and 32C.
panel harness connector to 32B Yellow Splice at 32A and 32C to oil
starting motor “Bat” terminal. pressure switch.
1F Red Main harness/left instrument 32C Yellow Splice in 32A to main harness/
panel harness connector to rear harness connector.
starting motor “Bat” terminal. 428 Dark Blue Main. harness/right instrument
3 Black Main harness/rear harness panel harness connector to

‘4
connector to starting circuit splice in 42C and 42H.

3c Black
relay.
Main harness/right
panel harness connector
instrument
to
42C Dark Blue Main harness/left
panel harness connector
splice in 42B.
instrument
to q
starting circuit relay. 42H Dark Blue Splice in 42B to light harness
12A Resistance Main harness/left instrument connector.
Wire panel harness connector to al- 42J Dark Blue Light to light.
ternator No. 1 terminal. 42K Dark Blue Light harness connector to
128 Purple Main harness/left instrument light.
panel harness connector to 42N Dark Blue Light to light.
main harness/right instrument 50A Gray Main harness/left instrument
panel harness connector. panel harness connector to
13D Orange Main harness/right instrument splice at 508 and 50C.
panel harness connector to 50B Gray Splice in 50A to oil pressure
main harness/left instrument sender.
panel harness connector. 5oc Gray Splice in 50A to main harness/
13E Orange Splice in 13D to fuel injection rear harness connector.
pump. 64A Black Main harness/left instrument
21A White Main harness/left instrument panel harness connector to
panel harness connector to horn connector.
start circuit relay. 648 Black Horn connector to horn.
66C Yellow Main harness connector to
compressor connector.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9015-10 Electrical System TM- 1136 (Mar-78)

42G

p=J;pJ42F
CT ENGINE WATER ENGINE OIL
TO HORN
SWITCH

VOLTMETER
TEMPERATURE GAUGE PRESSURE GAUGE
IGNITION SWITCH

13A 21 50

13
a-
WIPER/WASHER HORN SWITCH. START SWITCH HYDRAULIC OIL
SWITCH FILTER INDICATOR LIGHT

MAIN CIRCUIT
BREAKER BLACK

LEFT INSTRUMENT PANEL

TO MAIN HARNESS CONNECTOR

32D 38

TRANSMISSION OIL FILTER

SENDERS
0 START AID
SOLENOID
288

HYDRAULIC OIL
FILTER SENDER
50D

START SAFETY REAR HARNESS TO MAIN

SWITCH HARNESS CONNECTOR
T44209N
Fig. &Wire Terminal Location (Part 111)( -xxxxx) *

*NOTE: After xxxxx, See Fig. 27.

hitho in U.S.A.
 JO750 Crawler Bulldozer System Testing 90
TM- 1136 (Mar-78) Electrical System -- 9015-l 1

I The following is an explanation

minal Location (Part III).
of Fig. 6-Wire Ter- No.

42D
Color

Dark Blue
Routing

Splice at 42E, 42F and 42G to

No. Color Routing left instrument panel harness/
main harness connector.
1D Red Main circuit breaker to left in- 42E Dark Blue Voltmeter to splice in 42D.
strument panel harness/main 42F Dark Blue Engine temperature gauge to
harness connector. splice in 42D.
1E Red Ignition switch “Bat” terminal to 42G Dark Blue Engine oil gauge to splice in
main circuit breaker. 42D.
1G Red Main circuit breaker to left in- 50 Gray Hydraulic oil filter light to left
strument panel harness/main instrument panel harness/main
harness connector. harness connector.
12 Purple Ignition switch “Act” terminal 64 Black Horn switch to left instrument
to left instrument panel har- panel, harness/main harness
ness/main harness connector. connector.
12F Purple Wiper/washer switch through
wiper fuse to ignition switch 3A Black Start safety switch to rear har-
“Act” terminal. ness/main harness connector.
13 Orange Start switch to ignition switch 38 Black Start aid solenoid to splice in
“lgn” terminal. 3A.
l3A Orange Start switch to voltmeter. 3E Black Start safety switch to cab har-
138 Orange Voltmeter to hydraulic oil filter ness.
light. 32D Yellow Transmission oil filter sender to
13L Orange Cab relay to ignition switch rear harness/main harness
“lgn” terminal. connector.
21 White Start switch to left instrument 32E Yellow Transmission oil filter sender to
panel harness/main harness transmission oil filter sender.
connector. 50D Gray Hydraulic oil filter sender to
rear harness/main harness
connector.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9015-I 2 Electrical Sys tern TM- 1136 (Mar-78)

rc6:: '~~~~TO FUSE

AIR CONDITIONER 75 BLOWER MOTOR

THERMOSTAT
SWITCH

75A
\
74A 42s
f
73A

m
RIGHT LEFT

BLOWER MOTORS

DOME LIGHT
FUSE
AIR CONDITIONER
FUSE
3E3!iI1366A
CAB HARNESS TO
RIGHT INSTRUMENT PANEL
HARNESS CONNECTOR

,H.-p+IH lJ---rt--lK
1 I
FUSE HARNESS
CAB CIRCUIT
CONNECTOR
BREAKER

T44.2101

Fig. 7-Wire Terminal Location (Part IV) ( -xXxXx) *

*After xxxxx, See Fig. 27.

Litho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Mar-78) Electrical System 9015-13

The following is an explanation of the Fig. -/-Wire No. Color Routing

Terminal Location (Part IV).
66 Yellow Air conditioner thermostat to
No. Color Routing blower motor switch “Clutch”
terminal.
IH Red Cab relay through cab circuit 66A Yellow Air conditioner thermostat to
breaker to main circuit break- cab harness/right instrument
er. panel harness connector.
1J Red Fuse harness connector to cab 73 Red Air conditioner right blower
relay. motor to blower motor switch
1K Red Fuse harness connector to air “Low” terminal.
conditioner fuse. 73A Red Air conditioner left blower
1L Red Dome light fuse to air condi- motor to blower motor switch
tioner fuse. “Low” terminal.
3E Black Start safety switch to cab har- 74 Yellow Air conditioner right blower
ness/right instrument panel motor to blower motor switch
harness connector. “Medium” terminal.
13L Orange Cab relay to ignition switch 74A Yellow Air conditioner left blower

42s Blue
“lgn” terminal.
Dome light connector to dome
light fuse. 75 Orange
motor to blower motor switch
“Medium” terminal.
Air conditioner right blower
q
, ,

motor to blower motor switch

“High” terminal.
75A Orange Air conditioner left blower
motor to blower motor switch
“High” terminal.

Litho in U.S.A.
~_-_~
90 System Testing JD 750 Crawler Bulldozer
9015-14 Electrical System TM- 1136 (Mar-78)

DIAGNOSING FAILURES Engine Turns Slowly

Burnt or bad solenoid switch contacts.
Batteries Bad contact of brush or worn out brushes.
Burnt commutator.
Battery Undercharged
Commutator mica too high.
Too much load from accessories. Shorted or grounded armature coil.
Too much engine idling. Bad tension on brush spring.
Accessories running on low charging system volt- Armature too close to pole core.
age. Low battery charge.
Low charging system output. High resistance in battery cables.
Constant load on battery.
Starting Motor Keeps Running
Low Battery Output
Defective solenoid.
High resistance in circuit. Defective start switch.
Low electrolyte level. Defective start circuit relay.
Low specific gravity. Short in wiring. I
Defective battery cell.
Cracked or broken battery case. Noise With Starter Running
Low battery capacity. Armature hitting stationary components.
Starting motor drive gear worn.
Battery Uses Too Much Water

Cracked battery case. Starting Motor Will Not Rotate,

Battery being overcharged. Engine Will Not Turn
Defective battery. Burnt or bad solenoid switch contacts.
Open, shorted, or grounded solenoid switch pull-in
Starting Circuit windings.
Open, shorted, or grounded solenoid switch hold-in
Solenoid Switch Makes and
windings.
Breaks Contact Rapidly
Bad contact of brush or worn out brushes.
Low battery. Burnt commutator.
Poor connection. Commutator mica too high.
Open in solenoid hold-in circuit. Open or grounded field winding.
Open, shorted or grounded armature coil.
Starting Motor Rotates But Will Not Bad tension on brush spring.
Turn Engine Grounded positive brush spring.
Grounded positive brush holder.
Damaged sprag clutch pinion. Damaged engine.
Broken drive lever.
Broken drive lever pivot bolt.
Broken magnetic switch plunger hook.
Defective sprag clutch drive.

Litho in U.S.A.
JD750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Mar-78) Electrical Sys tern 9015-15

NOTE: If starting motor does not run, connect a High Charging System Voltage
voltmeter to the solenoid “S” terminal (white wire) and
High resistance at regulator connections.
to a good ground. With key switch on, push start
Defective regulator.
switch.
Shorted field windings.
Brush sleeve clip grounded.
Voltmeter Shows Battery Voltage

Defective starting motor. Noisy Alternator

Defective solenoid switch.
Defective drive belt.
Worn or defective bearings.
Voltmeter Does Not Show Battery Voltage
Drive belt loose.
Defective key switch or start switch. Pulley not aligned.
Defective starting circuit relay.
Defective wiring between key switch and starting Alternator Will Not Charge
circuit relay.
Drive belts slipping.
Defective wiring between battery and solenoid “S”
Defective wiring.
terminal.

‘1
Alternator defective.
Start safety switch defective or maladjusted.
Neutral lock lever not in lock position.
Defective main circuit breaker.
Batteries completely run down.
Gauges
Voltmeter Shows Low Voltage (Engine Running)
q
Alternator not operating.
Charging Circuit
Defective voltage regulator.
Low Charging System Voltage Short circuits.
Alternator drive belt loose or broken
High resistance in circuit connections.
Defective voltmeter.
Defective wiring.
Low amperage output of alternator.
Voltmeter Needle Fluctuates
Defective regulator.
Defective batteries. Shorted or loose connections.
Drive belts slipping. Alternator defective.
Alternator drive belt loose.
Low Charging System Output Low idling speed.

Drive belts slipping.

Defective batteries.
Grounded, shorted or open field windings.
Defective rectifier bridge.
Defective diode trio.
Defective stator.
Defective regulator.

Litho in U.S.A.
90 Sysfem Testing JD750 Crawler Bulldozer
901516 Electrical System TM- 1136 (Mar-78)

Voltmeter or Hour Meter Does Not Work Accessories

No voltage to the gauge. No voltage to accessory.
Defective gauge. Blown fuse (if equipped)
Defective wiring.
Indicator Lights Will Not Light Defective accessory.
Defective switch.
No voltage to indicator light.
Defective light or sending unit.
Air Conditioner
Defective wiring.
Blown air conditioner fuse.
Lights Defective cab relay or circuit breaker.
Defective high temperature switch
Limited Capacity from Lights
(xxxxx- )
High resistance in circuit or poor ground on lights. Defective pressurizer blowers.
Low battery charge. Defective thermostat or compressor
Defective light switch. Defective condenser fans (xxxxx- 1 I
Defective wiring.
No Lights Will Work Mechanical failure.
Blown thermal fuse.
Defective light switch.
Defective wiring.
Horns
Defective circuit breaker.
Horn Operates After Being Hit
Individual Lights Will Not Work
Points open because of wear.
Defective sealed beam or bulb. Dirt between points (horn will operate
Bad ground on light. normally the next time).
Defective wiring.
Horn Will Not Sound
Cold Weather Starting Aid
Horn or switch defective.
Solenoid Will Not Activate Defective wiring.
Defective solenoid.
Defective starting aid switch.
Defective wiring.
Neutral lock lever not in lock position.

Solenoid Activates, Fluid Will Not Flow

Out of fluid.
Starting aid line or nozzle clogged.
Fluid too cold.

Litbo in U.S.A.
JD 750 Crawler Bulldozer System Testing 90
TM- 1136 (Mar-78) Electrical System 9015-17

Precautions If booster batteries are used to aid in starting the

engine, be sure to connect them correctly.
Certain precautions should be taken when testing or
servicing the electrical system.
A CAUTION: Wear eye protection and
move all metal items from hands.
re-

A CAUTION: To prevent injury from a spark

or short circuit, DISCONNECT THE BAT-
IMPORTANT: In a 24 volt system, be sure that
TERY GROUND STRAP OR TURN OFF BATTERY
the 12 volt battery charger or booster battery is not 1
DISCONNECT SWITCH when working on any part connected across both batteries when using it as a
of the electrical system. This will also prevent
booster. Connect only to one battery as follows:
accidental starting.
Connect the positive cable from battery charger to
positive terminal of one of the batteries. Connect
When removing the batteries, disconnect the the negative cable from the charger to the negative
battery ground strap first. When installing the bat-
terminal of the same battery.
tery, connect the ground strap last.

NEVER CHANGE THE POLARITY OF THE BAT-

TERY CONNECTIONS. Changing the polarity may
damage some components and wiring in the system.

DO NOT ATTEMPT TO POLARIZE THE ALTER-

NATOR after connecting the battery. No polarization is
needed. Any attempt to do so may damage the alter-
nator, regulator, or circuits.

Never operate the alternator in an open circuit.

Never short or ground the alternator terminals.

Do not disconnect the voltage regulator while the

alternator is running.

T44211N

l-Battery Charger or 4-Battery to Starter

12-volt Booster Battery Cable
2-Machine Batteries S-Battery to Battery
(with cab) Cable
3-Battery to Disconnect GMachine Batteries
Switch Cable (Without Cab)

Fig. &Connecting Battery Charger

or Booster Battery to Machine Batteries

Litho in U.S.A.
90 Sys te% Tesfing JD 750 0-a wler Bulldozer
9015-l 8 Electrical System TM- 1136 (Mar-78)

When using booster batteries, prevent fire by doing VISUAL INSPECTION

the following:
Carefully inspect the electrical system for tips on the
failure. Check to see if the machine can be operated
1. When possible, use equipment with a switch in
without further damaging the system.
the line connecting the booster battery to the machine
batteries.
Always check these items before turning on
switches or running the machine:
2. Always “move” the connector clips to make sure
they are tight.
1. Look for worn wires that could cause grounds or
shorts and dangerous sparks. Shorted wires can
3. If only jumper cables are available, be sure to
damage the charging system.
connect the machine batteries first; then when con-
necting the booster battery, be very careful when
2. Lookfor loose or broken wires. They can damage
holding the cable clips. When disconnecting, be sure to
the regulator.
break the connection at the booster battery first.
3. Inspect all connections, especially battery con-
When connecting a fast charger to a battery in the
necting points. Acid film and dirt on the battery may
machine, be very careful. First remove the battery
cause current flow between the battery terminals,
ground strap or turn off battery disconnect switch to
causing current leakage. Check the battery ground
prevent fires and damage to the alternator.
strap for the correct connection.

Do not put metal tools or other items on the battery

4. Check the battery electrolyte level. Excessive
as they can cause a short circuit.
loss of electrolyte shows overcharging.

A CAUTION: GAS FROM BATTERY ELEC-

TROLYTE IS FLAMMABLE. Keep all sparks
5. Check the alternator drive belt tension.

and fires away from the battery. When charging the

6. Inspect for parts that are too hot after the ma-
battery, gas is made more rapidly. Be sure the
chine has been stopped for a while. They will have the
place where the battery is charged has plenty of
odor of burnt insulation. Feel the alternator or regula-
moving air.
tor. Heat in these parts when the machine has not been
operated for some time is asure sign of charging circuit
A CAUTION: BATTERY ACID IS HARMFUL
ON CONTACT with the body or most mate-
problems.

rials. See Group 1671 for ,emergency care tips

If your visual inspection does not show the possible
when acid comes in contact with the body.
failure, but your inspection does show that the machine
can be run, turn the starting switch to the “accessory”
IMPORTANT: DISCONNECT BATTERY ground
position and check out the accessory circuits - lights,
strap or turn off battery disconnect switch when
cigar lighter, horn. How do each of these components
welding on the unit to prevent damage to the
work? Look for sparks or smoke, which might be
charging system.
caused by shorts.

Turn the starting switch to the “on” position. Now

start the machine. Check all gauges for good opera-
tion, and see if the system is charging or discharging.

Many electrical failures cannot be found even if the

machine is started. So, a thorough and complete in-
spection of the electrical system is necessary.

Litho in U.S.A.
 JD750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Mar-78) Electrical System 9015-l 9

TESTING AND ADJUSTMENT Testing Battery Voltage

The circuits tested in this group are the starting Battery condition should be checked first. It is nec-
circuit, charging circuit and accessory circuit. Circuits essary to the testing of the starting circuit to have the
tested in the accessory circuit are the lighting circuit, batteries fully charged and free of shorted or bad cells.
miscellaneous accessory circuit, instrument and indi- Use the following test to determine voltage at the
cator circuit and air conditioning circuit. batteries.

Failure of the engine to crank may be caused by one 1. Attach positive (+) voltmeter lead to positive (+)
of a number of things. Any one of several components battery post with the cable to starting motor. Attach
in the starting circuit may be causing the failure, or negative (-) voltmeter lead to negative (-) grounded
possibly a weak battery. Another reason for failure battery post.
could be broken, disconnected or loose leads or cor-
roded connections. 2. Crank engine.

Both a visual and an electrical check should be 3. Voltmeter should read at least 20 volts. If above
made to find the problem before removing any com- the minimum, continue testing. If below the minimum,
ponent. If this is not done, a component may’ be refer to Group 1671 to recharge or replace battery.
removed only to find it was not causing the failure.
System Short Test
Be sure to use exact electrical test equipment when
The following is an easy way of finding an electrical
making electrical tests. Defective equipment will pre-
system short quickly.
vent the service technician from doing thorough work
and may cause failure of the electrical system.
NOTE: Because of the very small amount of current
used by the voltage regulator at all times, the regulator
Before you start the circuit test, quickly review the
must be disconnected during this test.
precautions on Page 90-9015-17 and make the fol-
lowing checks:
1. Be sure batteries are fully charged.

1. Check battery electrolyte level.

2. Remove the connector from top of voltage regu-
2. Look for corroded terminals.
lator.
3. Check battery polarity.
4. Check for acid film and dirt on top of battery.
3. Disconnect the ground cable from the grounded
5. Test the charge of the battery (See “Testing
battery.
Battery Voltage”).
4. Connect a 24-volt test lamp between the nega-
Batteries
tive battery post and the disconnected cable.
The batteries are the base of the electrical system.
During operation, the storage batteries change chemi- 5. If there is a short, the test lamp will still light when
cal energy into electrical energy needed for starting the all accessories are turned off.
engine or operating the accessories when the engine is
not running. 6. By disconnecting and reconnecting each electri-
cal circuit, one at a time, the shorted circuit can be
For good operation, the battery must do two jobs: found.

1. It must supply current for starting the engine. 7. When a disconnected circuit causes the test
lamp to go out, that is the shorted circuit. Now follow
2. It must supply current when the need is more that circuit and find and correct the cause of the short.
than the output of the charging system.

Litho in U.S.A.
.-
90 System Testing JD750 Crawler Bulldozer
901 S-20 Electrical System TM- 1136 (Mar-78)

Starting Circuit Then the plunger is pulled in by means of the

magnetic pull of the pull-in and hold-in windings, and
The starting circuit is made up of the batteries,
the sprag drive clutch is pushed out on the armature
starter with solenoid switch, starter circuit relay, start-
shaft by the driver to engage the pinion flywheel ring
safety switch, start button, circuit breaker, key switch,
gear. At this time, the pinion and ring gear are not fully
and connecting wires.
engaged before the contact plate closes between the
contacts.

When the contacts are fully closed, battery current

flows directly into the field windings and to the arma-
ture coils through the contact plate, and causes the
armature to rotate. This pushes the clutch pinion fur-
ther to engage completely with the ring gear. As the
armature rotates, the sprag clutch also rotates, and the
sprags move to the side a little and are pushed be-
tween the shell and the sleeve. This holds the pinion to
the armature shaft and makes it possible for torque to
move to the pinion for engine turning.

When the solenoid plunger is pulled in, less mag-

netism is needed to hold it in. Then the pull-in winding
----------A is shorted with the contact plate, and only the hold-in
.T38489 .
winding operates to hold the plunger in place when the
l-Shift Lever 7-Battery Terminal start switch remains closed.
2-Plunger E-Motor Terminal
3-Solenoid g--Battery Positive Cable When the engine starts, the flywheel gear may move
4-Hold-In Winding lO-Starting Motor the pinion faster than the armature is running. The
!&Pull-In Winding 11-Sprag Clutch
pinion, spinning faster than the clutch shell, causes the
G-Start Switch 12-Contact Disk
sprags to turn in the opposite direction to let the pinion
Fig, B-Basic Starting Circuit and sleeve overrun the shell and armature. To prevent
overrunning too long a time, the start switch should be
There is constant voltage to the key switch “BAT” released as soon as the engine starts.
terminal. The current flows from the batteries through
the “B” terminal on the starting motor solenoid to the When the start switch is released after the engine
circuit breaker, and then to the key switch. starts, the current flows from the contact plate to both
the pull-in and hold-in windings in the same direction.
When the key switch is turned to “IGN” position, the The windings are wound to have their magnetic fields
switch contact points close and current flows to the act in opposite directions so that when the current
start switch. When the start switch is pushed in, the flows in the same direction, the magnetic fields cancel
switch closes and current goes to the starting circuit each other out. The plunger moves to the neutral
relay and through the relay to the start safety switch. position by way of the plunger spring, releasing the
pinion from the flywheel.
If the neutral lock lever is in lock position, the start
safety switch lets current go to ground, which lets the For additional information on starting circuits,
contact points in the starting circuit relay close. Current refer to “Starting Circuits” in FOS Manual -
then flows from the starting motor “B” terminal through ELECTRICAL SYSTEMS.
the starting circuit relay to the starting motor solenoid
“2 terminal closing the contact points and letting
battery current flow into the starting motor hold-in
winding and pull-in and also to the armature coils
through the field windings and brushes.

Litho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Mar-78) Electrical System 9015-21

Testing the Starting Circuit 1. Nothing Takes Place

When making test, the battery voltage should not fall

Test No. 1
below 20 volts. Never run a starting motor more than
20 seconds at a time or it will get too hot. Let the motor
Check the reading on the voltmeter, which is in the
cool a minimum of two minutes before running it again.
instrument panel. If the reading is 20 to 24 volts, the
circuit to the start switch is working correctly. Go to
With the neutral lock lever in lock position, turn key
Test No. 2.
switch on and push start switch. One of five things
takes place if the starting circuit is defective:
If the instrument panel voltmeter doesn’t read cor-
rect voltage, check for 20 to 24 volts at points shown by
1. Nothing takes place - there is no sound, because
lettered seauence in Fia. 10.
r ------
the solenoid contacts did not close.
1

2. A sound in the solenoid is heard, but the starting

motor does not operate.

3. The starting motor is running, but the engine OR

1
does not turn over.

4. The starting motor turns over the engine slowly or

with variable speed.

5. The engine starts but the starting motor drive

does not disengage from the flywheel.

Check out these five problems as follows:

NOTE: When making the following tests, the neutral

lock lever must be in lock position, the key switch
turned to “IGN” and the battery disconnect switch R-RED
B-BLACK
closed. W-WHITE
OR-ORANGE

T&S2221
l-Battery Disconnect 6-Key Switch
P-Batteries 7-Start Switch
3-Starting Motor &Voltmeter
4-Starting Motor Solenoid g--Start Circuit Relay
54lain Circuit Breaker lo--Start Safety Switch

Fig. IO-Starting Circuit Test No. 7

When a place is found where 24 volts is read, the

circuit is working correctly from there back to the
battery. The problem is between the point where the
voltage was first read and the last point where no
voltage was found.

Litho in U.S.A.
L-- ____ -- -~
 90 System Tesfing JD750 Crawler Bulldozer
9015-22 Electrical Svsfem TM- 1136 (Mar-781

Test No. 2 Test No. 3

Connect voltmeter to starting motor solenoid termi- Connect voltmeter to starting circuit relay small ter-
nal with white wire. minal with white wire.

r------f

R-RED
B-BLACK
W-WHITE
OR-ORANGE
OR-ORANGE

M4213N T44214N

i-Battery Disconnect 7-Start Switch l-Battery Disconnect 7-Start Switch

P-Batteries 8-Voltmeter (Instrument 2-Batteries S-Voltmeter (Instrument
3-Starting Motor Panel) 3-Starting Motor Panel)
4-Starting Motor Solenoid S-Starf Circuit Relay 4-Starting Motor Solenoid S-Start Circuit Relay
S-Main Circuit Breaker lo-Start Safety Switch S-Main Circuit Breaker lo-Start Safety Switch
S-Key Switch 1 i-lest Voltmeter e-Key Switch 1 l-Test Voltmeter

Fig. 1 l-starting Circuit Test No. 2 Fig. 12-Starting Circuit Test No. 3
I

Push start switch. Push start switch.

A starting circuit that is not working correctly with 20 No voltage at this point is the result of a problem with
to 24 volts at this point is the result of a defective the start switch or wiring. Go to Test No. 5.
solenoid. See Group 0422 for solenoid tests.
Voltage at this point is the result of a defective relay,
If there is no voltage, go to Test No. 3. start safety switch or wiring. Go to Test No. 4.

Litho in U.S.A.
 JD 750 Crawler Bulldozer System Testing 90
TM- 1136 (Mar-78) Electrical System 9015-23

Test No. 4 Test No. 5

Connect voltmeter to starting circuit relay small ter- Connect voltmeter to start switch terminal with white
minal with black wire. wires.

------ r------i
r 1 1

R-RED -
B-BLACK z
R-RED
W-WHITE B-BLACK
OR-ORANGE
W-WHITE
OR-ORANGE

T44215N c T44216N

l-Battery Disconnect 7-Start Switch l-Battery Disconnect 7-Start Switch

2-Batteries S-Voltmeter (Instrument a-Batteries S-Voltmeter (Instrument
3-Starting Motor Panel) 3-Starting Motor Panel)
4-Starting Motor Solenoid g-Start Circuit Relay 4-Starting Motor Solenoid g-Start Circuit Relay
S-Main Circuit Breaker W-Start Safety Switch Ii--Main Circuit Breaker X)-Start Safety Switch
6-Key Switch 1 l-Test Voltmeter 6-Key Switch 1 l-Test Voltmeter

fig. 73-Staffing Circuit Test No. 4 Fig. 74Starfing Circuit Test No. 5 I
I

Push start switch. Push start switch.

If there is voltage, the start safety switch is defective If there is no voltage after pushing switch, the switch
or not adjusted correctly or the wiring between the start is defective.
circuit relay and start safety switch is open.
If there is voltage at this point, but not in Test No. 3,
If there is no voltage now, but there was in Test No. there is defective wiring between start switch and start
3, the start circuit relay or wiring between the start circuit relay.
circuit relay and starting motor is defective.

Litho in U.S.A.
 90 System Testing JD750 Crawler Bulldozer
9015-24 Electrical System TM- 1136 (Mar-78)

2, Solenoid Contacts Make A Sound But the Start- High Resistance Test
ing Motor Did Not Operate
Disconnect the fuel injection pump wiring lead at the
This shows that the circuit problems are in the pump to prevent the unit from starting.
starting motor. If the solenoid switch contacts close
and the switch starts to make -and break contact rap- Connect voltmeter to ground and to solenoid battery
idly, there is an open circuit in the hold-in winding of the terminal. Operate starting motor and check voltage
solenoid. In any case, the starting motor should be against a similar reading of the battery. Be sure to use
removed and tested as covered in Group 0422. a pin connector at the battery post. If there is a dif-
ference of more than 0.8 volt, make the appropriate
3. Starting Motor Ran But Did Not Turn The Engine test (Fig. 15). Check for defective wires or connections.
I
Over

The starting motor is getting enough current to run.

The problem, then, is either the shifting of the drive
assembly into engagement with the flywheel, a broken
armature shaft, or a dirty or defective drive assembly.
The starting motor must be disassembled for service or

q
repair of any of these items. See Group 0422.
‘I
4. Starting Motor Turned The Engine Over Slowly
Or With Variable Speed

With sluggish starting motor operation, connect a

voltmeter across battery terminals and operate the
starting motor. With a slow-running starting motor the
voltage should be less than 20 volts. If more than 20
volts, check for high resistance between the batteries
and the starting motor.

If voltage reading is less than 20 volts, the problem

is either the batteries or the starting motor. Check
battery condition first. See Group 1671 for testing
batteries and Group 0422 for testing starting motor.

Lifho in U.S.A.
 JO 750 Crawler Bulldozer System Testing 90
TM- 1136 (Mar-78) Electrical System 9015-25

_-----
r .
1 5. Engine Starts But the Starting Motor Drive Does
I I
Not Disengage From The Flywheel
There is a defect in the drive parts or solenoid pull-in
winding, or solenoid contacts, or solenoid control cir-
cuit (which will not let the drive disengage), or starting
circuit relay.

Check for voltage at the starting circuit relay terminal

with a white wire. (See Fig. 14). With the start switch
disengaged, there should be no voltage at this termi-
nal.

If there is no voltage at the terminal, the starting

circuit relay or start switch is defective. Replace as
necessary.

‘t
If there is no voltage at the terminal, the starting

q
B-BLACK
motor or solenoid needs repairing. See Group 0422.
W-WHITE
OR-ORANGE

-
z T44217N.

l-Battery Disconnect 8-Key Switch

2-Batteries 7-Start Switch
3-Starting Motor 8-Voltmeter (Instrument
4-Starting Motor Panel)
Solenoid %-Start Circuit Relay
!&-Main Circuit 1 O-Start Safety Switch
Breaker

I Fig. IdSiarting Circuit - High Resistance Test

High Resistance Test Values

Test Points Maximum Voltage Reading

A-F 0.2
B-C 0.2
C-D 1.0
B-E 1.2

If voltmeter readings are higher than shown in the

above high resistance test, check for defective battery
cables or connections.

Lifho in U.S.A.
 90 System Testing JD750 Crawler Bulldozer
9015-26 Hectrical Sysfem TM- 1136 (Mar-78)

Charging Circuit

For information on the basics of an alternator

Fe3 charging circuit, read “Charging Circuits” in
FOS Manual - ELECTRICAL SYSTEMS.
cl Q

The charging system is made up of the batteries,

alternator, regulator, key switch and connecting wires.

The purpose of the charging circuit is to give

operating power when the machine is running and to
keep the batteries fully charged.
L

138490 w
In an alternator, the magnetic field of the rotor is
moved across stationary conductors in the stator. This 1-Stator !5-Regulator
2-Regulator Terminal 6-Brushes
makes possible permanent connection between the
3-Diodes ;I--Rotor Slip Rings

q
stator winding and the output terminal. Slip rings are &Rotor Winding (Field)
4-Output Terminal
‘I used to move the field current to the rotor field wind-
ings. Fig. 76-Alternator Circuit
I

The alternator supplies power in the form of three- The transistor regulator is an electronic switching
phase alternating current and voltage. An alternator device made up mostly of transistors, resistors, and
has a high current output at low speeds. The alternat- diodes to form a completely static unit having no mov-
ing current is changed to direct current by a three- ing parts.
phase full-wave rectifier circuit using six silicone recti-
fier diodes. Since the diode will move current in only The transistors are used to turn the alternator field
one direction (from alternator to battery or load), the current on and off and are controlled by the resistors
alternator does not need a cutout relay. and the Zener diode.

The alternator output current is controlled by the The Zener diode is a special diode that will break
current flow through the field coil (rotor). The amount of down and make possible a reverse flow of current
current needed is controlled by the regulator. Since when voltage becomes a certain value, without dam-
there is very little residual magnetism in the alternator, aging the semi-conductor material. This diode re-
it is necessary to supply a small amount of excitation sponds to the maximum desired voltage and turns the
current to the field (rotor) to start the current genera- transistor on or off to control charging system voltage.
tion. The resistance wire in the main engine harness
supplies this starting current when the key switch is A temperature compensating resistor changes re-
turned on. sistance according to temperature and controls the
operating point of the Zener diode so that a higher
Once the alternator is activated, the voltage regula- system voltage is supplied in cold weather, when
tor takes over control of the system voltage. needed, and a lower system voltage in warm weather.

The regulator has a silicone controlled rectifier as The operation of the regulator is much like a switch,
the current controlling device for the field. There is no turning the alternator field current on and off as the
isolation diode or reed switch used to separate the electrical supply changes because of the changing
regulator from the batteries when the engine is not electrical load. This action takes place many times a
running. second, so fast it cannot be found in the alternator
output.

bitho in4J.S.A.
 JD750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Mar-78) Electrical System 9015-27

Testing the Charging Circuit Test No. 2 - Testing Alterna for and Regula for With
Voltmeter (Key Switch “On”)
NOTE: The system test will be the same for the 16
amp (without cab) or 42 amp (with cab) alternator but Connect voltmeter to the regulator terminal and to
the results will be different. The 16 amp alternator has ground (Fig. 17).
I
a capacitor connected to the output terminal and
With all accessories off, turn the key switch on. The
ground. If this capacitor leaks, it will run down the
battery. If it becomes open, the diodes in the alternator voltmeter should read approximately 11.4 volts for 16
may be damaged by voltage spikes. amp alternator and 6.9 volts for 42 amp alternator.

A reading above the given voltage most probably is

Test No, 1 - Testing Alternator and Regulator With
caused by a defective rotor field circuit. Loosen alter-
Voltmeter (Key Switch “OFF”)
nator belt and turn alternator. If reading is still high, the
problem may be an open circuit or high resistance in
alternator rotor field circuit, defective brushes, discon-
nected regulator, or a defective regulator.

A reading below the given voltage may be caused by

a defective regulator, shorted rotor field windings, or an
open circuit in the resistance wire.

If the voltage is not correct, make Test No. 4. \

Test No. 3 - Testing Altertia for and Regulator With

Voltmeter (Engine Running)

Connect voltmeter to the regulator terminal and to

ground (Fig. 17).

R-RED
With all accessories off, run engine at approximately
OR-ORANGE 1400 rpm. The voltmeter should read 27.5 volts or
P&PURPLE
more.

144218N A reading lower than 27.5 volts may be caused by a

discharged battery, defective diodes or a defective
l-Battery Disconnect S-Key Switch stator.
Switch S-Voltmeter
2-Batteries 7-Alternator
3-Starting Motor S-Regulator Move the voltmeter lead from the regulator terminal
and Solenoid !&Resistance Wire to the output terminal. Voltmeter should read approxi-
4-Main Circuit Breaker lo-Test Voltmeter mately the same as it did at the regulator terminal.

Fig. 17-Voltmeter Connected to Regulator Terminal

I

With the key switch off, connect voltmeter to the

1 regulator terminal and to ground (Fig. 17). Reading
should be zero volts.

If there is a reading, the cause could be a shorted

diode or shorted key switch.

Litho in U.S.A.
90 Sys tern Testing JD750 Crawler Bulldozer
9015-28 Electrical Sys tern TM- 1136 (Mar-78)

Test No. 4 - Testing Alternator Field Circuit on With key switch off, take off regulator. Let regulator
Unit be held up by wires.

IMPORTANT: Do not let regulator body come in

contact with both the grounded surface and the
output terminal; to do so will probably cause fail-
ure of wiring harness, alternator and regulator.

Connect voltmeter to field terminal and to ground.

Turn on key switch.

On alternator with cab, the reading on the field

terminal should be approximately 6.8 volts. Alternator
without cab reading will be approximately 11.3 volts.

Start engine. The reading on the alternator with cab

should be approximately 6.5 volts; without cab ap-
proximately 8.2 volts.
R-RED
OR-ORANGE
PU-PURPLE If the field circuit is open, the reading at the field
GR-GREEN
terminal will be approximately 22.5 volts.

2-442198 If there is an open in the regulator, the reading at the

l-Battery Disconnect GVoltmeter (instrument field terminal will be zero volts.
Switch Panel)
2-Batteries -/-Alternator
3-Starting Motor and &Regulator
Solenoid g--Resistance Wire
4-Main Circuit Breaker lo-Test Voltmeter
5-Key Switch

Fig. l&Voltmeter Connected to Field Terminal

Litho in U.S.A.
 JD 750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Mar-78) Electrical System 9015-29

Test No. 5 - Testing Alternator On Unit Using With key switch off, disconnect green lead from field
Voltfne ter terminal and disconnect regulator at connector. Con-
nect a jumper wire from the output terminal to the field
terminal. Connect voltmeter negative lead to ground
and connect voltmeter positive lead to regulator termi-
nal (Fig. 19). Run engine at approximately 800 rpm.

If batteries are fully charged, the voltmeter reading

will be approximately 28 volts. If batteries are not fully
charged, it may be necessary to run engine a little
faster. Do not go over 32 volts.

If approximately 28 volts were noted in this test

(regulator disconnected), and if in Test No. 3 the
voltage was below what it should have been (regulator
connected), then the regulator is probably defective
and should be replaced. If voltage does not go higher

-+ R-RED
in this test, and the field to circuit checks out in Tests
No. 2 and 4, then the problem is in the stator or diodes

-+ OR-ORANGE
P&PURPLE
GR-GREEN
and the alternator should be removed for service. See
Group 1672.

5T0 * P4422ON

l-Battery Disconnect GVoltmeter

Switch 7-Alternator
2-Batteries 8-Regulator
3-Starting Motor and g-Resistance Wire
Solenoid lo-Jumper Wire
4-Main Circuit Breaker 1 l-Test Voltmeter
5-Key Switch 12-Regulator Connector

Fig.19-Jumper Wire and Voltmeter Connection

I

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9015-30 Electrical Svstem TM- 1136 (Mar-78)

Test No. 6 - Testing Alternator Output

If not using JDST-23 Tong-Type Ammeter, discon-

nect wire from alternator output terminal and connect
ammeter (Figure 20). Connect voltmeter leads to out-
put terminal and ground terminal. Connect a carbon
pile resistor (turned off) to the battery. Run engine at
approximately 1400 rpm. Use a master tachometer to
measure rpm. Adjust carbon pile to get maximum
alternator output at 26 to 30 volts. The ammeter should
read within 80 per cent of the alternator’s rated output.

Test No. 7 - Testing Regulator

The regulator must be checked with an alternator
that is in good condition. Connect voltmeter (with r 0.1
volt accuracy) to output and ground terminals.

With charged batteries and regulator at operating

temperature (15 minutes operation) the voltage should
be as specified for the temperature. See chart below. If T44221h’
batteries are not fully discharged, it may be necessary
l-Battery Disconnect GVoltmeter
to connect a i/4-ohm resistor in series with the am-
Switch 7-Alternator
meter. 2-Batteries 8-Regulator
Z&Starting Motor and g-Resistance Wire
Temperature* Voltage Solenoid lo-Test Voltmeter
4-Main Circuit Breaker 1 l-Ammeter
5-Key Switch
40°F (4°C) 28.4 to 29.3 volts
60°F (16°C) 28.2 to 29.0 volts Fig. 20-Voltmeter and Ammeter Connections
80°F (27°C) 27.9 to 28.7 volts
100°F (38°C) 27.6 to 28.2 volts NOTE: Letters in fig. 20 are for high resistance test
120°F (50°C) 27.4 to 28.3 volts which follows.
140°F (60°C) 27.1 to 28.1 volts

*Measured one inch (25 mm) from regulafor

If voltage is above or below that of the above chart,

make the high resistance test on next page.

If high resistance in a connection is not found, stop

engine and with key switch off, put in a new regulator.

Litho in U.S.A.
 JD 750 Crawler Bulldozer System Testing 90
TM- 1136 (Mar-78) Electrical System 9015-31

High Resistance Test Lighting Circuit

Turn off battery disconnect and connect ammeter as The lights are controlled by the light switch. A 15
shown in Fig. 20. Turn battery disconnect on, start amp circuit breaker keeps the lights from circuit over-
I
engine and get a IO-amp charge rate. load.

Check the voltage between the points shown in the Testing Lights
chart below. Be sure to use a pin connector to connect
the voltmeter to battery post. r------7 -

If voltmeter readings are higher than the maximum

shown in the chart, there is probably high resistance in
a poor connection.

When there is a high resistance in the charging

system, the regulator cannot control alternator voltage
and keep the battery in a fully charged condition.

Test Points Maximum Voltage Reading*

A-C 0.3 Volt

B-D 0.3 Volt
R-RED
B-E 0.3 Volt
PU-PURPLE
DKBL-DARK BLUE
*70-amp charging fate.

YZ- T44222N

l-Battery Disconnect 6-Cigar Lighter

2-Batteries Resistor
3-Starting Motor and 7-Cigar Lighter
Solenoid S-Light Circuit
4-Main Circuit Breaker
Breaker g-Light Switch
5-Key Switch lo--Canopy Light(s)
11-Gauge Back Lights (5)

Fig. 21 -Lighting Circuit

All Lights
If all lights will not work, check to see if the cigar
lighter will work. If the cigar lighter works, the problem
is the light circuit breaker, light switch or wiring.

If the cigar lighter will not work, check wiring be-

tween the light circuit breaker and the key switch
“ACC” terminal.

Litho in U.S.A.
90 System Testing JD750 Crawler BulldQzer
9015-32 Electrical System TM- 1136 (Mar-78)

Separate Lights Instruments and Indicators

If the separate lights will not light, use the following The voltmeter and hour meter are electrical gauges.
procedure. Power comes to the gauges through the “IGN” termi-
nal of the key switch.
Connect voltmeter to lamp terminal and lamp frame.
Voltage comes to the electrical indicator lamps at
Voltmeter Reads Battery Voltage one terminal of the lamp at all times the key is on
ignition. The sending unit or pressure switch gives a
Defective bulb ground to the lamp so that current can flow through the
High resistance at an inside connection lamp lighting it if the following conditions are met.

If voltmeter reading is 0.5 volt or more below battery The pressure switches (which are on the oil filters)
voltage, connect voltmeter between lamp frame and a for the equipment hydraulic oil filter light and the
good ground. transmission filter light are normally closed switches so
the lamps will be on with the key on and engine not
Voltmeter Reading Is Higher Than 0.1 Volt running. When the engine is running, oil pressure
opens the switch(es), removing ground from the lamp.
Defective lamp ground
The sending unit switches are normally open. If the
If voltmeter reading to ground is lower than 0.1 volt, filter has a restriction, the sending unit switch closes,
connect voltmeter between lamp terminal and battery giving ground to the lamp.
positive post that is connected to the starting motor.

Voltmeter Reading Exceeds 0.5 Volt

Defective light switch or key switch

Defective or disconnected wiring

If voltage is more than it should be, use voltmeter

across some different points between the lamp termi-
nal and the battery post to find the point of excessive
resistance. Readings should not exceed 0.1 volt.

Litho in U.S.A.
 JD 750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Mar-78) Electrical System 901533

Testing Instruments and Indicator Lights

indicators If any indicator light does not work, disconnect the
wire at the pressure switch and put it to a good ground.
Turn on key switch.

r If the indicator now lights, the pressure switch is

defective or not grounded.

If the indicator still will not light, remove instrument

panel mounting screws and pull out panel.

Check the bulb for voltage to the orange wire at the

indicator light.

If the bulb is good, the orange wire has voltage

applied with the key switch on “IGN,” and the indicator

‘f
did not light by grounding the pressure switch wire, the

q
problem must be that the wiring is defective between -L
the pressure switch and indicator light.

If the equipment hydraulic or transmission filter light

does not go off when the engine is started and oil
T44223N
warmed up or comes on during machine operation, I
l-Battery Disconnect g-Equipment Filter
check filters. The pressure switch or sending unit could
2-Batteries Indicator Light also be defective, which would cause the indicator to
3-Starting Motor and Sending Unit stay on.
Solenoid 1~Hour Meter
4-Circuit Breaker 11-Transmission Filter
5-Key Switch Indicator Light
GVoltmeter 12--Transmission Filter
7-Equipment Hydraulic Indicator Light
Oil Filter Indicator Pressure Switch
Light 11Transmission Filter
S-Equipment Filter Sending Units
Indicator Light
Pressure Switch

I Fig. 224nstruments and Indicators Ctrcuits

Voltmeter and Hour Meter

If the voltmeter or hour meter does not work, check

for voltage at the gauge.

If there is voltage at the gauge, the gauge is defec-

tive or not correctly grounded.

If there is no voltage, check the wiring.

Litho in U.S.A.
 90 Sys tern Testing JD750 Crawler Bulldozer
9015-m Electrical System TM- 1136 (Mar-78)

=. Testing Miscellaneous Accessories

R-RED
PU-PURPLE
B-BLACK
OR-ORANGE
lX3X3;::""' BLUE

Y-YELLOW
W-WHITE

l'S75931
= TEST POINTS

l-Battery Disconnect 1 &Horn Is-Air Conditioner Compressor ( -xXxXx)

2-Batteries 11-Fuel Injection Pump O&-Air Conditioner Thermostat ( -xXxXx)
2-Starting Motor and Solenoid 12-Start Aid Switch 21-Blower Motor Switch ( -xXxXx)
4-Main Circuit Breaker O-Starting Aid Solenoid 22-Air Conditioner Cab Blower
9-Key Switch 14-Start Safety Switch Motors ( -xXxXx)
9-Wiper Fuse M-Cab Relay 23-Cigar Lighter Resistor
7-Wiper Switch l&Dome Light Fuse 24-Cigar Lighter
&-Wiper 17-Dome Light 2S-Cab Circuit Breaker
9-Horn Switch M-Rear Wiper 26Resistor
27-Windshield Washer Motor
29--Reverse Warning Switch
29-Reverse Warning Alarm

Fig. 23-Miscellaneous Accessories

NOTE: For air-conditioning circuit after Serial No. Turn key switch to “IGN” position and push starting
I
xxxxx, see Fig. 24. aid switch. If a sound is heard at the starting aid
solenoid, check line and nozzle to see if they are
Testing Starting Aid completely open or not (see Group 0505).

If starting aid does not get the fluid in the engine, use
If no sound is heard, check voltage with voltmeter at
the following tests to correct.
light blue wire connection (wire to switch) on solenoid
and to ground. If a reading of 20 to 24 volts is shown on
Turn the key switch to “IGN” position and push start
the voltmeter, the solenoid is defective. If a reading of
switch. If engine turns over, start safety switch is
less than 2 volts is shown, the wiring to the starting aid
activated and problem is in starting aid switch, starting
switch or the switch is defective.
aid solenoid or starting aid fluid line or nozzle is re-
stricted.

Litho in U.S.A.
JO750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Mar-78) Electrical System 901535 I

All Accessories (Except Air Conditioning) If the blower motors will not run on one speed, check 1
I
the voltage at the terminal of the blower motor switch at
If an accessory will not work, check fuse (if ap-
the speed setting of the motor which is not working
plicable). Check for voltage at accessory. If there is
(see Fig. 23).
voltage at the accessory with key switch on, accessory
is defective or not correctly grounded.
If there is voltage at the switch, the motor is defec-
tive.
If there is no voltage at the accessory, check for
voltage at switch (if equipped). If there is no voltage on
If the blower motors will not run at any speed, check
the accessory side of the switch with the switch on,
the red wire at the “B” terminal of the blower motor
switch is defective. If there is voltage on the switch, the
switch. If there is voltage, the switch is defective. If not,
wiring is defective.
the wiring to the switch is defective.

Air Conditioning (Serial No. -xXxXxX)

If the compressor will not run, remove left control
If none of the air conditioner electrical components console cover. Check for voltage at “C” terminal of the
work, check the fuse. If the fuse is good, check to see if blower motor switch with the switch on. If no voltage is
the dome light will work. read at this point and it can be read at the “B” terminal,
the switch is defective. - ..
If the dome light will not light, check for voltage to the ‘1
cab relay. With the key switch on “IGN” both large If voltage was obtained at “C” terminal, put a jumper m
terminals and the small terminal should read 20 to 24 wire across both terminals of the thermostat control
volts. If the small terminal and only one large terminal switch. Turn on blower motor switch. If compressor
reads voltage, the relay is defective. now runs, the thermostat control switch is defective. If
compressor still will not run, check for voltage at com-
If only the small terminal reads voltage, the cab pressor.
circuit breaker or wiring is defective.
If there is voltage, but compressor will not run, there
If the small terminal with orange wire does not read is a defect in the compressor (see Group 1830).
voltage, wiring between the relay and key switch is
defective. If there is no voltage at the compressor with the
thermostat switch jumped, the wiring is defective.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9015-36 Electrical Sysfem TM- 1136 (Mar-78)

Air Conditioning (Serial No. xxxxx- ) Power flow to the compressor clutch is as follows:

When the pressurizer switch (4) is on, the “C”

terminal has voltage applied. Voltage is applied
through the thermostat switch (6), if on, through the
high temperature switch (7), and activates the air con-
ditioning relay (9). If the air conditioning fuse (10) is
good, the relay passes voltage to the condenser fan
(12) and thermal fuse (14).

Voltage is applied through the thermal fuse to the

compressor clutch.

If the high temperature switch (7) opens, voltage is

removed from the air conditioning relay and applied to
the plugged condenser indicator.

If thermal fuse is found to be blown, check for loss of

refrigerant or other cause of high temperature or low
pressure, such as a line restriction.

Ts7594N If condenser fan or compressor clutch is inoperable,

turn on air conditioning controls and trace the voltage
l--Cab Circuit Breaker 12-Condenser Fan Motor path from compressor back to voltage source until
2-Gab Relay 13-Superheat Shut-Off
defective component or wiring is found.
3-Pressurizer Fuse Switch
4-Pressurizer Switch 14-Thermal Fuse
S-Pressurizer Motor %-Compressor Clutch
GThermostat Switch
7-High Temperature R - Red
Swiich OR - Orange
&-Plugged Condenser B - Black
Indicator G - Green
“Air Conditioning Relay BR - Brown
1 O-Air Conditioning Fuse Y - Yellow
11-Air Conditioning W - White
Circuit Breaker

Fig. 24-Air Conditioning Circuit (xxxxx- )

If pressurizer motor doesn’t work, check the fuse (3,

Fig. 24). Jumper wire or test the switch with voltmeter.

bitho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Nov-75) Power Train 9020-l

Group 9020
POWER TRAIN
GENERAL INFORMATION

Disconnect Clutch Drive Shafts

The engine disconnect clutch lets the engine release The splitter drives two drive shafts which are con-
from the splitter drive for cold weather engine starting. nected to the right and left transmissions.

The engine disconnect clutch is a dry-disk assembly These drive shafts are torsionally dampened inter-
placed on the engine flywheel. The clutch disk is held nally to absorb drive line shock.
in an engaged position by clutch springs. When the
disconnect clutch is engaged, engine power travels Parking Brake
from the engine crankshaft thru the disconnect clutch,
Between each transmission and its final drive is a
splitter drive, and drive lines to the transmission.
parking brake. These brakes are for parking only, since

Splitter Housing
The splitter drive is mounted to the clutch housing.
the Dynamic Braking action of the hydrostatic drives is
used for normal operational braking. q
, ,

Its function is to divide engine power for driving two These brakes are of a hydraulically-disengaged,
hydrostatic transmissions. spring-engaged, dry-disk type. They are automatically
applied when there is a loss of transmission charge
The splitter also drives the main hydraulic pump and pressure or when the engine is turned off.
provides a PTO shaft for driving a winch.
Final Drive
The splitter is a simple five-gear drive unit used to
Power is sent from the transmissions to the drive
divide engine power into two outputs. The gears are all
sprocket by a double reduction final drive. A spur gear
in constant mesh.
and planetary system give a 38.23 speed reduction.
The final drive shaft pinion and final drive gear make up
The main hydraulic system pump is driven by the left
the spur system; the planetary system is in the outer
side idler of the splitter. The right side idler may also be
end of the final drive assembly.
used to drive an auxiliary pump.
The final drive housings are fastened to the out-
The splitter gear train is pressure lubricated by a
board side of the transverse case.
small Geroter pump. A dipstick is provided for checking
the oil level in the splitter housing.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9020-2 Power Train TM-l 136 (Nov-75)

Key Part Description Group No.

1. Left-Hand Transmission ............. . 0360

2. Clutch Disconnect Lever. ............ .. 0715
3. Clutch Disconnect Cable ............ 0715
4. Left-Hand Transmission Drive Shaft . . . . . 0325
5. Splitter Housing Dipstick. ............ . 0841
6. Splitter Housing .................... . . 0841
7. Clutch Throw-Out Searing ........... 0752
8. Planet Housing ..................... 0250
9. Drive Sprocket ..................... .. 0130
10. Final Drive Housing Cover. .......... . . 0250
11. Right-Hand Final Drive Housing. ..... .. 0201
12. Right-Hand Transmission ............ . 0360
13. Right-Hand Transmission Drive Shaft . . 0325
14. Splitter Housing Filler Tube .......... . 0841
15. Clutch Disconnect .................. . . 0752
16. Clutch Housing ..................... 0752

Legend for Fig. l-Component Location-Power Train

bitho in U.S.A.
JD 750 Crawler Bulldozer System Testing 90
Power Train 90204
TM- 1136 (Feb-77)

r------1
I
ENGINE

I- -- ---
7

DISCONNECT
CLUTCH
r-l

SPLITTER
DRIVE

I I

DRIVE SHAFT DRIVE SHAFT

I I

-- -I- --1

L. H.
TRANSMISSION

T4485.W

Fig. P-Power Train Hock Diagram

Litho in U.S.A.
 90 System Testing JD750 Crawler Bulldozer
9020-6 Power Train TM-1 136 (feb-77)

DIAGNOSING FAILURES

Disconnect Clutch Drive Shafts

Clutch Slips Drive Line Makes Noise

Worn or burnt clutch disk. Not enough lubricant.

Oil or grease on clutch disk. Inspect, grease seals in both ends of U-Joints.
Clutch disk may have been improperly installed Lubricate with correct grade of lubricant.
Check for correct installation. Bearings in U-Joints worn.
Clutch linkage not adjusted correctly. Replace bearings.
Adjust clutch linkage. Splitter drive output shaft bearing is loose.
Pack with proper grease or check for worn bear-
Clutch Makes Noise ing.
Torsional dampeners in drive shaft are damaged.
Distorted or rough clutch shaft splines.
Replace drive shaft.
Replace clutch shaft. Loose yoke nut.
Clutch disk loose at hub rivets. Check splines and tighten connecting nuts to
Replace clutch disk. specifications.
Worn pilot bearing. Too much run-out or distorted yoke.
Replace pilot bearing. Disassemble and replace damaged parts.
Worn release bearing.
Replace release bearing.
Parking Brakes
Clutch Drags See Group 9026.

. Distorted or rough clutch shaft splines.

Replace clutch shaft.
Clutch disk hub tight on clutch shaft.
I Clutch disk facings loose.
High points on clutch disk.
Replace clutch disk.
Worn clutch components.
Replace components as needed.
Linkage out of adjustment.
Adjust linkage.

Litho in U.S.A.
JD750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Feb-77) Power Train 9020-7

Final Drives VISUAL INSPECTION

Much can be learned about the general condition of
Makes Too Much Noise
the power train by visual inspection.

Damaged or worn final drive gears or bearings.

Check for these conditions:
Disassemble and replace worn or damaged parts
as necessary.
1. Cap screws torque not correct
2. Housing cracked or broken
3. Gasket failure
4. Oil seals and/or O-rings worn or not installed
correctly.
5. Inspection for worn or damaged parts if any part
of power train is disassembled.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9020-8 Power Train TM-1 136 (Feb-77)
-
TESTING AND ADJUSTMENT

Engine Disconnect Clutch

l’48496N

l-2 Inches (51 mm) of Free Travel 4-Bell Crank

2-Adjustable End Yokes 5-Clutch Shaft
3-Bell Crank

Fig. 3-Disconnect Clutch Linkage

To adjust the disconnect clutch linkage, remove the

pin that secures one of the adjustable end yokes (2,
Fig. 3) to the bell crank (3 and 4) or to the clutch shaft
(5). Turn the adjustable end yoke to shorten or length-
en the linkage until 2 inches (51 mm) of travel (1) of the
clutch control lever is required to bring the clutch
release bearing into contact with the release levers.

Litho in U.S.A.
-
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Flow Meter) 9025-l I

Group 9025
HYDRAULIC SYSTEM (Flow Meter)
Component Location . . . . . . . . . 9025-3 This group has troubleshooting tips, schematic and
General Information.. . . . . . 9025-5 block diagrams and tests of the hydraulic system. By
Operation .. .. . . ... . 9025-g following the tests given, the defective component can
Schematic and Block Diagrams . .. . : 9025-10 be found and removed for more testing, repair or
Diagnosing Malfunctions. ... . . 9025-17 replacement.
Testing
Checking Oil Lines and Hoses. . . . 9025-21 Service instructions for components removed from
Checking Dozer Circuit for Leakage . 9025-21 the unit can be found in separate sections of this
Lift Control Valve Lift Check Test . . 9025-21 manual.
Tilt Control Valve Lift Check Test . . 9025-22
Checking Tilt or Ripper COMPONENT LOCATION
Cylinder for Leaks. .. . 9025-22

‘t
The component location drawing is a list and illus-
Checking Lift Cylinder

q
tration of the hydraulic components and where they are
for Leaks....................... 9025-23 found on the unit.
Checking System Relief Valve
Pressure Setting . .. . . 9025-23
Checking Hydraulic Sump . . 9025-23
Checking Hydraulic Pump Flow 9025-23

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9025-2 Hydraulic System (Flow Meter) TM- 1136 (Apr- 79)

i-Hydraulic Oil Sump 10 -Tilt Cylinder Junction Block

2-Hydraulic Sump Oil Filter 11 -Tilt Cylinder
3-Hydraulic Oil Sump to Hydraulic Pump Line 12 -Tilt Cylinder Retract Circuit
4-Control Valve Return to Hydraulic Oil Sump 13 -Tilt Cylinder Extension Circuit
Circuit 14 -Right-Hand Lift Cylinder
!I&-Right-Hand Lift Cylinder Raise Line 15 -Lift Cylinder Raise Circuit
6-Right-Hand Litt Cylinder Lower Line 16 -Litt Cylinder Lower Circuit
7-Left-Hand Lift Cylinder Lower Line 17 -Hydraulic Pump
&Left-Hand Lift Cylinder Raise Line 18 -Control Valve
8-Left-Hand Lift Cylinder 18A-Control Valve Tilt Section
18B-Control Valve Lift Section

Legend for Fig. 1-Bulldozer Hydraulic System

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Flow Meter) 9025-5
I

GENERAL INFORMATION As rotor speed increases, centrifugal force causes

the vanes to follow the cam-shaped contour of the ring,
The dozer hydraulic system consists of a sealed
providing the necessary pumping action. System
hydraulic sump, a vane-type hydraulic pump, a dozer
pressure, fed behind the vanes and inserts, assures
control valve assembly, two lift cylinders, tilt cylinders,
sealing contact of the vanes on the ring cam contour
a hydraulic sump filter, and a double selector valve and
during operation.
ripper cylinder, if so equipped.
The intra-vane design provides a means of control-
The hydraulic sump is the reservoir for the equip-
ing the outward thrust of the vanes on the cartridge ring
ment hydraulic system. The hydraulic sump is pres-
at different positions of vane travel around the ring. Full
surized to keep out dirt and hold pressure for a positive
system pressure is continuously applied through the
flow to the hydraulic pump.
rotor intra-vane passages for this outward vane thrust.
This force is applied only over the area between the
A hydraulic sump filter is mounted along side of the
vane and insert. Because this area is small, thrust is
hydraulic sump. The sump filter bypass valve is located
correspondingly light.
in the sump filter housing head. When the hydraulic
sump filter becomes plugged, return oil will bypass the
During vane travel through the pressure quadrants,
filter and flow directly to the hydraulic sump. _
full system pressure is also applied against the bottom
are a of the vane. The valving of pressure to and from
A pressure switch mounted on the sump filter hous-
the bottom area of the vanes is through holes drilled in
ing head will turn on a warning light on the instrument
the rotor. This selective application of pressure keeps
panel just before the sump filter bypass valve opens to
the vane in constant radial hydraulic balance in all
indicate that the filter needs service.
quadrants of the cartridge ring.

The dozer hydraulic pump is located on the left side

The dozer control valve assembly is located below
of the splitter housing. The dozer hydraulic pump is of
the operator’s station connected to the main frame.
the balanced, single-cartridge, intra-vane design with
the pump inlet port located in the cover and the outlet
The dozer control valve assembly is an open-center,
port located in the body.
two-spool, stack-type valve. In an open-center valve,
pressure oil will flow through the control valves to the
Inlet flow of oil from the reservoir is ported through
hydraulic sump when the control valves are in neutral.
the cover to the pump cartridge. The cartridge then
discharges the oil through porting in the pressure plate
The system relief valve is located in the (inlet) port
and pump body to the hydraulic system.
plate of the dozer control valve. The system relief valve
setting is 2000 + 175 - 0 (13 800 + 1200 - 0 kPa)
The cartridge is composed of two flex side plates, an
(138 + 12 - 0 bar).
inlet support plate, ring, rotor, vanes, inserts, and outlet
support plate. The rotor is driven within the cartridge by
The lift and tilt work sections are separate bodies
the pump drive gear located in the splitter housing.
containing singe spools. All sections have lift checks
which serve as one-way valves to prevent oil on the
applied side of the cylinders from flowing back through
the valves.

Litho in U.S.A.
 90 System Testing JD750 Crawler Bulldozer
9025-6 Hydraulic System (Flow Meter) TM- 1136 (Apr- 79)

A detent in the lift valve spool end cap retains the Blade tilt cylinder bypass operation is shown in Fig.
spool in the float position. The lift section contains two 2. As the piston bottoms, the steel ball is forced off its
circuit relief valves and an anti-cavitation check valve. seat by the shaft. Oil in the pressure circuit now forces
The circuit relief valves pressure setting is 2250 + 175 the other ball off its seat. This opens a path for oil flow
( - 0 psi (15 500 + 1200 - 0 kPa) (155 + 12 - 0 bar). to the trapped oil circuit between the two tilt cylinder
rod ends. These bypass valves keep the trapped oil
The valve sections of the dozer control valve are circuit between the two tilt cylinder rod ends filled with
connected in series. In the series connection, the re- oil. When one tilt cylinder is fully extended and the
turn oilfrom the tilt control valve is directed to the inlet other is fully retracted, oil will flow through both open
of the lift control valve. This insures that the tilt cylinder bypass valves and return to sump. This allows the
operates first when both the lift and tilt control valves system to purge itself of any air in the trapped oil
are activated. circuit.

The tilt cylinder on the hydraulic tilt dozer is double- When the piston moves away from the bottomed
acting and uses “V” type packing seals on its pistons. condition, the spring forces the balls against their
Replaceable non-metallic wear rings are used on pis- seats. This prevents oil flow through the bypass valve
ton retainers to prevent scoring of the cylinder barrels. in mid-stroke positions.

-
eJ
T64428N

l-Pin !+Shaft (2 used)

2-Spring 8-Trapped Oil
3-Steel Ball (2 used) 7-Pressure Oil
4-Piston 8-Cylinder Barrel

Fig. 2-Tilt Cylinder Bypass Valve

(Hydraulic Tilt Angle Dozer)

The blade tilt cylinders on the hydraulic tilt angle

dozers are single acting. The rod ends of both cylin-
ders are connected together. The head ends are each
connected to the control valve. One to the top work
port, and one to the bottom work port.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Flow Meter) 9025-7

Hydraulic Junction Block The crawler uses two lift cylinders. The lift cylinders
are double-acting and use “V” type packing seals on
their pistons. Replaceable non-metallic wear rings are
used on piston retainers to prevent scoring of the
cylinder barrels.
om PRESSURE OIL
I
Each lift cylinder piston contains two “bypass poppet
assemblies” which allow oil to flow through the piston

r
to return whenever it is bottomed. This reduces the
w forces created by uneven lift cylinder rod travel. Un-
even rod travel results from the variable range of blade
tilt positions.

Lift cylinder bypass operation is shown in Fig. 4. As

the piston bottoms, the two poppets connected to the
return circuit are forced off their seat. Oil in the pres-
sure circuit now forces the other poppets back, open-
ing a direct path to return, thus relieving pressure in the
circuit. ‘4
q
Oil enters and exits the poppet seat areas (insert)
T56570~ through drilled passages which intersect the poppet
l-Pressure Oil 5-Orifice Plate
cavity. In addition, two milled slots in the piston faces
a--Medium Pressure Oil B-Slot intersect the drilled passages to vent oil when the
S-Return Oil 7-10 Cylinder Head piston is bottomed. When the piston moves away from
4-Return From Cylinder End the bottomed condition, a spring returns the poppets
Rod against their seats, preventing oil flow in mid-stroke
positions.
Fig. 3-Hydraulic Junction Block
(early units)

A hydraulic junction block for the tilt circuit is located

on the grille housing in front of the oil cooler radiator
assembly. This junction block houses a 0.144 in. (3.66
mm) “orifice plate” which is threaded into the head end
of the tilt cylinder circuit with the slot facing out. The
purpose of the orifice is to slow the speed of the tilt
cylinder for fine grading operations. In the tilt left posi-
tion, the orifice restricts the flow of oil to the head end
of the tilt cylinder. In tilt right position it restricts return
oil flow from the head end of the tilt cylinder back to the
control valve, slowing the blade tilt function.

On later units the junction block is replaced by two

fittings attached to the grille housing. The fitting in line
with the head end of the tilt cylinder circuit also con-
tains the orifice mentioned in the above paragraph and
functions identically to one in the junction block.

Litho in U.S. A.
90 System Testing JD750 Crawler Bulldozer
9025-8 Hydraulic System (Flow Meter) TM- 1136 (Apr- 79)

T45451N

l-pressure Oil 4-Poppet

2-Return Oil !5-Rod
3-Piston

Fig. 4-Lift Cylinder Poppet Operation

Litho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Flow Meter) 9025-g

I
Double Selector Valve OPERATION
Hydraulic oil from the hydraulic sump flows down to
the hydraulic pump. Hydraulic oil enters the pump
cover and is directed to the pump cartridge. The re-
volving rotor in pump cartridge pumps the oil to the
outlet port. From the outlet port, pressure oil flows to
the dozer control valve assembly.

If both the lift and tilt control valves are in neutral,

pressure oil will flow through the dozer control valve
assembly,to the hydraulic sump filter and then on to the
hydraulic sump.

When the tilt control valve is activated, pressure oil

is directed to the tilt cylinder. Return oil from the tilt
cylinder flows through the dozer control valve to the
hydraulic sump filter and then on to the hydraulic sump.
PRESSURE OIL
RETURN OIL
When the lift control valve is activated, pressure oil
TRAPPED OIL is directed to the lift cylinders. Return oil from the lift
cylinders flows through the dozer control valve to the
l-Pressure Oil ~-TO Tilt Cylinder(s) hydraulic sump filter and then on to the hydraulic sump.
2-Return Oil S-From Blade Tilt Section
3-Trapped Oil ~-TO Rear Auxiliary Function If the unit is equipped with tilt cylinder(s) and rear
auxiliary function such as a ripper, the hydraulic sys-
Fig. 5-Double Selector Valve
tem will also contain a double selector valve.
The double selector valve is available as a field
With the double selector valve handle forward,
option only. The double selector valve is connected
pressure oil from the tilt control valve is directed to the
into the tilt circuit between the blade tilt section and the
tilt cylinder(s).
tilt cylinder. The valve is mounted to main frame on the
right-hand side along side of the engine.
With the double selector valve handle pulled back,
pressure oil from the tilt control valve is directed to the
The double selector valve acts as a diverter valve to
rear auxiliary function.
divert pressure oil from the blade tilt section to the tilt
cylinder(s) or rear auxiliary function such as a ripper.

Litho in U.S.A.
90 Sys tern Testing JD750 Crawler Bulldozer
9025-10 Hydraulic System (Flow Meter) TM- 1136 (Apr- 79)

T664426N

l-Pressure Oil 5-Reservoir g-Junction Block

2-Low Pressure Oil 6-Hydraulic Sump Filter lo-Lift Cylinder
3-Trapped Oil 7-Dozer Hydraulic Pump 1 l-Tilt Cylinder
4-Return Oil 8-Dozer Control Valve 12-Angle Tilt Cylinders

Fig. 6-Bulldozer Hydraulics

(Tilt Cylinders Activated)

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
Hydraulic System (Flow Meter) 9025-11
TM- 1136 (Apr- 79)

T66060N

6-Ripper Cylinder 1 O-Double Selector Valve

l-Pressure Oil
7-Hydraulic Sump Filter 1 l-Lift Cylinder
~-LOW Pressure Oil
I-Hydraulic Sump 12-Junction Block
3-Trapped Oil
g-Hydraulic Pump 13-Tilt Cylinder
4-Return Oil
M-Angle *It Cylinders
5-Dozer Control Valve

Fig. 7-Bulldozer Hydraulics

(Ripper Cylinder Activated)

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9025-12 Hydraulic System (Flow Meter) TM- 1136 (Apr- 79)

DOZER
(CONTROL VALVE)
l----------
l

RIPPER
CYLINDER

I I L-,--J-----j I

TILT
CYLINDER
f0 HYDRAULIC
PUMP

HYDRAULIC
SUMP
FILTER
WITH
FILTER BYPASS
VALVE

T45455N

Fig. d-Block Diagram of Hydraulic System

(With a Ripper) (Tilt Dozer Shown)

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Flow Meter) 9025-13

DOZER
(CONTROL VALVE)

I 1 I
1 I I

HYDRAULIC

I SUMP
FILTER

FILTER BYPASS

T45456N

Fig. g-Block Diagram of the Hydraulic System

(Without Ripper) (Tilt Dozer Shown)

Litho in U.S.A.
90. System Testing JD750 Crawler Bulldozer
9025-14 Hydraulic System (Flow Meter) TM- 1136 (Apr-79)

T45457N

l-Low Pressure Oil !5-Hydraulic Sump 9-Blade Lift Cylinders

2--Return Oil 8-Hydraulic Sump Filter W-Blade Tilt Cylinder
3-Trapped Oil 7-Filter Bypass Valve 1 l-System Relief Valve
d-Main Hydraulic Pump 8-Circuit Relief Valves

Fig. lo-Bulldozer Hydraulic Schematic (Tilt Dozer Shown)

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Haraulic System (Flow Meter) 9025-15

I
r
I

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9025-l 6 Hvdraulic Svstem (Flow Meter) TM- 1136 (Apr- 79)

l-Tilt Cylinder 8-Lift Control Valve Section

2-Lift Cylinders g--Check Valve
3-Ripper Cylinders lO-Ripper Control Valve Section
4-Circuit Relief Valves (Ripper Circuit) 1 l-Bulldozer Pump
6--Circuit Relief Valves (IX Circuit) 12-Filter Relief Valve
g--System Relief Valve 13-Hydraulic Filter
7-Tilt Control Valve Section U-Reservoir

Legend for Fig, 11 -Bulldozer Hydraulic Schematic

Litho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
TM- I 136 (Apr- 79) Hydraulic System (Flow Meter) 902517

DIAGNOSING MALFUNCTIONS

DOZER HYDRAULIC PUMP

Shaft Seal Leaking
Pump Not Delivering Oil Worn shaft seal.
Check hydraulic sump oil level Replace shaft seal.

Pump drive shaft splines sheared. Broken diaphragm “vee” seal or backup gasket.
Remove pump and determine damage. Repair pump.

Pump inlet line plugged. Excessive internal leakage.

Remove and clean inlet line. Repair pump.

Oil viscosity too heavy. Oil Overheats

Drain oil and add new oil of proper viscosity.
Valves held open too long.
Return valve to neutral position immediately after
Air leaks at inlet. Pump not priming.
reaching end of cycle.
Check inlet pipe for leaks.
Incorrect relief valve pressure.
Vane or vanes stuck in rotor slots. Install correct cartridge.
Disassemble pump and inspect for damaged parts.
Wrong oil viscosity.
Insufficient pressure build-up in pump
Use proper viscosity of oil.
Test system relief valve
Dirty oil.
System pressure too low. Drain oil and clean or replace hydraulic sump filter.
Test system relief valve.
Restriction in pump suction line.
1 Worn parts causing internal oil leakage. Check and repair.
Replace pump cartridge.
Oil Foams
Pump Making Noise
Pump inlet line leaking.
Restricted or partially clogged inlet line. Tighten or replace.
Remove and clean inlet line.
Kink or dent in lines. -
Air leakage in inlet or pressure line. Check and replace.
Check line for leaking or loose connections.
Wrong viscosity of oil.
Shaft oil seal leakage.
Use proper viscosity.
Replace seal. Check shaft for scoring at seal area.
Replace if grooving is evident. Water in oil.
Drain and replace oil.
Aeration or Cavitation
Pump shaft oil seal leakage.
Remove pump and determine damage

Tilt, lift or ripper cylinder rod leakage.

Remove cylinder and determine damage.

Collapsed inlet hose.

Replace hose.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9025-18 Hvdraulic System (Flow Meter) TM- 1136 (Apr- 79)

System Pressure Is Low Functions Fail To Stay Raised

Relief valve ball held open by foreign material or bro- Leaking or broken oil lines or fittings from control valve
ken valve spring. Allows oil to return to hydraulic sump to cylinder.
because system relief valve will not seat. Check for leaks. Tighten or replace lines.
Clean or replace system relief valve.
Oil leaking past control valve spool(s).
No Hydraulic Pressure Replace control valve.

No oil in system.
Oil leaking past cylinder seals.
Fill with proper oil.
Replace worn parts in cylinder.

Oil of wrong viscosity.

Functions Fail To Work
Check oil specifications.
lnsuff icient oil in reservoir.
External oil line leaks. Add recommended oil.
Tighten or replace.
Relief valve not functioning.
Pump worn or damaged. Replace relief valve.
Test pump to specifications.
Insufficient relief valve pressure.
Control Valve Sticks Or Works Hard Clean or replace relief valve.

Return spring binding or broken.

Pump badly worn or damaged.
Replace spring.
Repair or replace pump.

Misalignment of control linkage.

Broken oil line.
Adjust control linkage.
Check for leaks and repair.

Foreign matter in spool bore.

Obstruction in oil lines or valve.
Clean control valve and hydraulic system.
Check flow of oil through system.

Dirty valve.
Worn control valve.
Clean valve.
Repair or replace valve.

Scored valve bore or bent spool.

Oil leaking past cylinder seals.
Replace valve.
Replace worn parts in cylinder.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Flow Meter) 902519

Functions Lift Slowly Oil leaking past cylinder packings or piston

poppet valves.
Cold oil.
Replace worn parts.
Allow oil to warm up.
Oil leaking past control valve.
Oil viscosity too heavy.
Replace or repair valve.
Use recommended oil
Restriction in suction line.
lnsuff icient engine speed.
Check and replace suction line.
Open crawler throttle.
Dirty oil filter (if used).
Air leak in suction line.
Replace or clean filter.
Check and tighten.
System relief valve dirty or leaking.
Badly worn pump.
Clean or replace system relief valve.
Replace or repair pump.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9025-20 Hydraulic System (Flow Meter) TM- 1136 (A pr- 79)

VISUAL INSPECTION

A CAUTION: Escaping fluid under pressure

can have sufficient force to penetrate the
When tightening connections, always use
wrenches to prevent damage to hoses, tubing
two
and
skin, kausing serious personal injury. Before dis- fittings.
connecting lines, be sure to relieve all pressure.
Before applying pressure to system, be sure all IMPORTANT: Tighten fittings only tight enough
connections are tight and that lines, pipes and to eliminate leaks. Do not overtighten connections.
hoses are not damaged. Fluid escaping from a very
small hole can almost be invisible. Use a piece of Check the type of oil being used in the hydraulic
cardboard or wood, rather than hands to search for sump. See Section I, Group V.
suspected leaks.
Also check the intervals at which the hydraulic sump
If injured by escaping fluid, see a doctor at once. filter must be changed. If the filter continually becomes
Serious infection or reaction can develop if proper clogged or obstructed at intervals which are much less
medical treatment is not administered immediate- than those specified, chances are that a failure is in
ly- progress. By inspecting the deposits within the filter,
the area from which the metal particles or hydraulic
Slow function operation may be an indication that packings are coming from can be determined.
the hydraulic system is leaking. Check all oil lines and
connections for leaks. Check the reservoir level. Operate the machine and see for yourself how the
machine operates. There could be some condition that
Leaks in the pressure side of the system can be might aid you in isolating the problem.
located by carefully inspecting the external area of the
components, fittings and hoses.

Check for a leak in any of the cast housings.

Check the suction side of the system for leaks by

examining the oil in the hydraulic sump. if air is being
drawn into the system, the oil will contain air bubbles
and will appear to foam.

Check all hydraulic lines. Pinched or bent lines will

restrict flow through the hydraulic system.

Dented tubing can cause oil foaming, heat, faulty

function operation or pump failure. Replace damaged
tubing immediately.

Inspect all pressurized hydraulic lines and connec-

tions for leaks. Tighten fittings or replace as necessary.

Wash inside and outside of oil lines and fittings with

clean diesel fuel to remove dirt before installing them
on the machine.

Litho in U.S.A.
JD 750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Flow Meter) 9025-21

TESTING AND ADJUSTMENT

A CAUTION: Escaping fluid under pressure

can have sufficient force to penetrate the
Checking Dozer Circuits for Leaks
The procedure for testing dozer circuits for leaks will
skin, causing serious personal injury. Before dis-
be as follows:
connecting lines, be sure to relieve all pressure.
Before applying pressure to system, be sure all
1. Check for leaking lines and fittings.
connections are tight and that lines, pipes and
hoses are not damaged. Fluid escaping from a very
2. Perform circuit cylinder leakage test.
small hole can almost be invisible. Use a piece of
cardboard or wood, rather than hands to search for
3. Perform circuit lift check test.
suspected leaks.
4. Replace the circuit anti-cavitation valves.
If injured by escaping fluid, see a doctor at once.
Serious infection or reaction can develop if proper
5. Replace the control valve section.
medical treatment is not administered immediate-
ly. Lift Control Valve Lift Check Test
Checking Oil Lines and Hoses If the lift control valve lift check valve appears to be
leaking, proceed as follows:
Slow function operation may be an indication that I

the hydraulic system is leaking. Check all oil lines and

1. Start engine. Raise the blade a few feet off the
connections for leaks.
ground and return the lift control lever to neutral posi-
tion.
Leaks in the pressure side of the system can be
located by carefully inspecting the external area of the
2. Slowly move the lift control lever back to the raise
components, fittings and hoses.
position. If the function settles before it begins to rise,
the lift check valve is probably leaking. Lower the
Check the suction side of the system for leaks by
blade to the ground and, if necessary, remove the lift
examining the oil in the hydraulic sump. If air is being
control valve for service.
drawn into the system, the oil will contain air bubbles
and will appear to foam.

Dented tubing can cause oil foaming, heat, faulty

function operation or pump failure. Replace damaged
tubing immediately.

Wash inside and outside of oil lines and fittings with

clean diesel fuel to remove dirt before installing them
on the machine.

When tightening connections, always use two

wrenches to prevent damage to hoses, tubing and
fittings.

IMPORTANT: Tighten fittings only tight enough

to eliminate leaks. Do not overtighten connections.

Litho in U.S.A.
90 System Testing JO750 Crawler Bulldozer
902522 Hydraulic System (Flow Meter) TM- 1136 (Apr- 79)
--
Tilt Control Valve Lift Check Test Checking Tilt or Ripper Cylinder for Leaks
If the tilt control valve lift check valve appears to be
NOTE: Before checking the cylinder for leaks, in-
leaking, proceed as follows:
spect the control valve.

1. Start engine. Raise the blade a few feet off the

If the control valve is not leaking and the function
ground.
continues to settle with the control valve in neutral, oil
is probably leaking past the packings in the cylinder,
2. Tilt blade to the right.
With the cylinder to be checked either fully extended
3. Return the tilt control valve lever to the neutral
or retracted, remove a hydraulic hose from one end of
position.
the cylinder. (If the cylinder is extended, remove hose
from rod end; if the cylinder is retracted, remove hose
4. Slowly move the tilt control lever back to the tilt
from the head end). Cap end of hose removed and
left position. If the function settles before it begins to
operate the cylinder. Because the cylinder piston is at
rise, the lift check valve is probably leaking. Lower the
the end of its stroke, the system relief valve will open.
blade to the ground and, if necessary, remove the tilt
control valve for service.
IMPORTANT: To prevent oil discharge from the
disconnected hose, be sure to operate cylinder in
same direction as chosen above. For example, if
hose is disconnected from the rod end, operate the
valve lever to extend the cylinder.

Examine the open port on the cylinder. If oil is

leaking excessively from the port, cylinder packings
are defective and should be replaced.

Be sure to replace any oil lost during each test.

Litho in U.S.A.
-
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Flow Meter) 902523

Checking Lift Cylinder for Leaks Checking Hydraulic Sump

Start engine to pressurize the hydraulic sump. Stop
NOTE: Before checking the lift cylinder for leaks,
the engine.
inspect the lift control valve.
IMPORTANT: The hydraulic reservoir is pres-
If the lift control valve is not leaking and the function
surized. Slowly remove the fill plug to relieve res-
continues to settle with the control valve in neutral, oil
ervoir pressure.
is probably leaking past the packings in the lift cylinder.
If no sound is heard when the filler plug is removed,
Raise the blade so the lift cylinder piston is not at the
replace the filler plug O-ring.
end of its stroke.
Checking Hydraulic Pump Flow
Then block right (or left) cylinder to prevent full raise
of the blade. Check oil lines, dozer control valve and cylinders
before checking the pump. To obtain-correct timing, the
Remove the head end cylinder hose. hydraulic oil should be at 70 to 75°F (21 to 24°C) and
the engine at fast idle.
Cap end of hose removed and operate the cylinder
to raise the blade. Check cycle times with a stop watch and refer to
Specifications for correct times.
IMPORTANT: To prevent oil discharge from the
disconnected hose, be sure to operate cylinder in If the cycle times are above the maximum times
the raise position. given below, the pump is probably faulty and should be
serviced.
Examine the open port on the cylinder. If oil is
excessively leaking from the port, cylinder packings Seconds
Cycle limes Min. Max.
are defective and should be replaced.
Blade raise . ... ... .. . .. 2.5
Be sure to replace any oil lost during each test. Blade lower. . . .. .. .. .. 2.5
(Power down)
Checking System Relief Pressure Setting
Install a 0 to 5000 psi (0 to 345 bar) (0 to 352
kg/cm*) gauge into the test port located in the inlet port
plate of the dozer control valve.

On the hydraulic tilt dozer, start the engine and fully

extend or retract the tilt cylinder.

On the hydraulic tilt angle dozer, disconnect and cap

one of the tilt cylinder hoses at the control valve. Also
cap the port on the control valve from which the hose
was removed. Move the control lever to extend or
retract the tilt cylinder.

With hydraulic control lever held at full travel, engine

at WOT and oil temperature at 122°F (50°C)
,the pressure reading should be 2000 + 175 - 0 psi
‘(13 800 + 1 200 - 0 kPa) (138 + 12 - 0 bar).

If pressure is not 2000 + 175 - 0 psi (13 800 +

1 200 - 0 kPa) (138 + 12 - 0 bar) replace system
relief valve.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
902524 Hydraulic System (Flow Meter) TM- 1136 (Apr- 79)

1-D-91 Tester Inlet Hose !5--6287 45” Union Adapter 9-D-91 Tester Outlet Hose
2-D-96 Double Union Connector 6-Hydraulic Pump lO-Nudey Hydraulic Tester
3-6288 45” Union Adapter 7-D-96 Double Union Connector 1 l-Loading Valve Handle
4-Dozer Control Valve 8-Hydraulic Pump Pressure Hose

Fig. 12-Hydraulic Pump Flow Test

(Using Nuday Tester)

Before proceeding with these tests, read the 3. Connect hydraulic tester into the circuit as shown
operating and instruction manual furnished with each in Figs. 12 and 13.
hydraulic tester and review the dozer function hydraulic
system. A thorough understanding of the tester and of 4. Open the hydraulic tester loading valve.
the hydraulic system will enable you to obtain more
exact and helpful data when performing the test. Also 5. Start the engine and run at 2100 rpm.
refer to Diagnosing Malfunctions for an orderly process
of eliminating the most likely trouble first. 6. Close the hydraulic tester loading handle until
600 psi (41 bar) (42 kg/cm2) and 170 to 190°F (77 to
1. With engine off, operate the dozer control valve 88°C) is reached.
to relieve any hydraulic pressure.
7. Measure pump flow.
2. Install a 0 to 5000 psi (0 to 345 bar) (0 to 352
kg/cm2) pressure gauge into the side test port of the 8. Minimum acceptable pump flow is 44 gpm (167
dozer control valve. L/min).

9. Close the tester loading handle until 2000 psi

(138 bar) (141 kg/cm2) is reached.

10. Measure pump flow.

11. Minimum acceptable pump flow is 38 gpm (144

L/min.)

Litho in U.S.A.
 \ -
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Flow Meter) 902525

P45459N

l-OTC Hydraulic Tester 5-Dozer Control Valve Assembly g-Y3001 Coupling Adapter
2-Y21-10 Tester Outlet Hose 6-6267 45” Union Adapter 10-6266 45” Union Adapter
3-Y3005 Union Fitting 7-Y21-10 Tester Inlet Hose 1 l-Hydraulic Pump Pressure Hose
4-Y3001 Coupling Adapter 6-Y3005 Special Adapter 12-Hydraulic Pump

Fig. 13-Hydraulic Pump Flow Test

(Using OTC Tester)

Litho in U.S.A.
 System Testing JD750 Crawler Bulldozer
9025-26 Hydraulic System (Flow Meter) TM- 1136 (Apr- 79)

Litho in U.S.A.
JO750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr-79) Hydraulic System (Analyzer) 9025A-1

GENERAL INFORMATION

l-Master Hydraulic System Analyzer 2-Tachometer/Temperature Reader

Fig. 1-Hydraulic System Analyzer

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9025A-2 Hydraulic System (Analyzer) TM- 1136 (Apr- 79)

The components of the Hydraulic Analyzer are the To check the hydraulic system follow this general
master hydraulic system analyzer, a tachometer/tem- procedure:
perature reader and an accessory kit for construction
equipment. 1. Install the specific orifice.

The master hydraulic system analyzer is used for 2. Connect a pressure gauge into a test port.
the measurement of pressures in the hydraulic system.
Two vacuum gauges are also available when needed. 3. Connect the Tachometer/Temperature Reader
Each gauge is connected to a coupling adapter. The to the unit.
coupling adapters and gauges have numbers for iden-
tification. 4. Start the engine and run at 1500 rpm.

The contents of the analyzer are: 5. Operate a control lever to put the cylinder to its
extended or retracted position. Hold control lever
1. One 0 to 5000 psi (0 to 34 500 kPa) (0 to 345 bar) in this position. This will cause the flow of oil to go
pressure gauge. through the orifice.

2. One 0 to 30 in. Hg (0 to 101.6 kPa) (0 to 1 016 6. When the temperature of oil is at the specific
mbar) vacuum gauge or a 0 to 150 psi (0 to 1 000 temperature, increase or decrease engine rpm to
kPa) (0 to 10 bar) pressure gauge. get the specific pressure. If the engine rpm are
more than the specification the circuit has leak-
3. One 0 to 30 in. Hg (0 to 101.6 kPa) (0 to 1 016 age or the pump is worn.
mbar) vacuum gauge.
The Hydraulic System Pretest Check Sheet (Fig. 2)
4. Four 0 to 400 psi (0 to 2 800 kPa) (0 to 28 bar) is a general list of possible symptoms (problems) in a
pressure gauges. hydraulic system.

The tachometer/temperature reader is used for the The Symptom Index is a list of symptoms from the
measurement of engine rpm and the oil temperature of Pretest Check Sheet and customer comments. In the
hydraulic system. The power for the reader is the unit’s next columns is the probable faulty component(s) and
electric system. The reader is adaptable to either 12 or a verification.
24 volt system.
Follow the procedure below to test the hydraulic
The accessory kit has the necessary fittings, adapt- system:
ers and orifices for the easy connection of analyzer to
hydraulic circuits. 1. Do the Pretest Inspection and Operational
Checks. Write the results on the Check Sheet.
The design of the Hydraulic Analyzer is for the test of
hydraulic systems. The test of hydraulic system condi- 2. Find the symptoms from the Pretest Check Sheet
tions are made at specific engine rpm and oil temper- in the Symptom Index, page 9025A-5.
ature. An orifice is installed into a circuit so all flow from
the hydraulic pump goes through it. 3. Do the verification test if necessary.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Analyzer) 9025A-3

CAUTION: Escaping fluid under pressure OPERATIONAL CHECKS

A can have sufficient force to penetrate the
skin, causing serious personal injury. Before dis- 1. Write the information for these items on the Hy-
connecting lines, be sure to relieve all pressure. draulic System Test Record (on back side of Check
Before applying pressure to system, be sure all Sheet).
connections are tight and that lines, pipes and
hoses are not damaged. Fluid escaping from a very Test specifications
small hole can be almost invisible. Use a piece of Pressure setting of circuit relief valves and system
cardboard or wood, rather than hands to search for relief valves
suspected leaks. Cycle times

If injured by escaping fluid, see a doctor at once. 2. Start the engine and run at 1500 rpm.
Serious infection or reaction can develop if proper
medical treatment is not administered immediate- 3. Operate functions until hydraulic oil is warm.
ly.
4. Run the engine at fast idle and operate each func-
PRETEST INSPECTION tion. Write the cycle times on the Test Record.
Inspect the operation of each function.
1. Write the machine identification information on
Check Sheet (Fig. 2) (Form M-5107 Stock 5-76). 5. Make a comparison between cycle times and the
specifications for cycle times.
2. Write the customer’s description of problem on
Check Sheet. 6. Check the applicable symptoms on Check Sheet.

3. Clean the machine as necessary for visual inspec- 7. Inspect hydraulic oil for bubbles.
tion.
8. Inspect filters for restrictions and particles.
4. Inspect these items: (write the results on Check
Sheet) 9. Go to the Symptom Index, page 9025A-5. Select
the probable faulty component(s). Do the verifica-
Hydraulic oil tion test if necessary.
Control valve(s)
Function return filter
Hydraulic lines and fittings
Cylinders

5. Correct any problems.

6. Do the Operational Checks.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9025A-4 Hydraulic System (Analyzer) TM- 1136 (Apr- 79)

HYDRAULIC SYSTEM PRETEST

CHECK SHEET

Customer Comments:

Machine Identification

PRETEST INSPECTION
. Clean machine as required. 3. Correct any problems.
. Perform all inspections. __ - ~-- -_- - -.__.- 4. Perform Operational Check.
Hydraulic Oil Ye5 NO Oil Cooler & No
Correct type 5- 0 Clear of dirt, debris q 0
Correct level c 0 Fan or shroud damaged 0 0
Bubbles in oil 0 G Belt tension and condition 0 0
Other 0 G Leaking cooler or lines 0 G

Control Valve(s) Yes NO Hydraulic System & No

Bent linkage yy -y 0 0
Bent or damaged lines
Properly adjusted linkage cl z External oil leaks G tl
Cylinder Rod(s) Bent 0 0
Frequently blown seals and fittings 0 0
Filters: Relum Hydraulic
Y* Ho N .!!!I
Ruptured Filter G 0 0 G
Plugged Filter 0 0 0 0
Metal Particles 0 0 cl 0
Packing Particles 0 0 n 0
New Filter Installed

OPERATIONAL CHECK

Start engine. Warm the hydraulic oil as described 3. Record cycle times. Check applicable
in the machine Technical Manual. 4. Reinspect hydraulic oil for bubbles.
With engine at specified fast idle, cycle each cir- 5. Go to Symptom Index in machine Technical Man
cuit. ual to select and verify faulty component.

No hydraulics
No power in hydraulics
Slow hydraulics, general
Slow hydraulics in circuit (Name of circuit)
Slow circuit in one direction (Name of circuit)
Chattering hydraulics, general
Chattering hydraulics in circuit (Name of circuit)
Circuit initially moves in opposite direction (Name of circuit)
Wrong circuit operates (Name of circuit)
Drift or leakdown in circuit (Name of circuit)
Sticky operation of control valves
Noisy pump
Filter warning indicator on
Slipping transmission

COMMENTS:

M-5.107-STOCK-S-76

P49052N

fig. Z-Hydraulic System Pretest Check Sheet

Litho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
T&4- 1 I.%
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I
SYMPTOM INDEX

No hydraulic operation. Disconnect clutch Check that disconnect clutch is

engaged (Group 0370).

Hydraulic pump drive If clutch is engaged, hydraulic

pump drive shaft is bad. In-
spect and make repair as nec-

raulic circuits operate System relief valve Do the System Relief Valve
slow. Test, page 9025A-6.

Possible: Hydraulic pump

‘I
Metal particles in

q
filter element.

Drift or leakdown in a Do the Cylinder Leakage

circuit. Test, page 9025A-10.

Possible: Blade control valve If the cylinder(s) are good, do

No power in circuit. the Circuit Leakage Test,

in one direction.

Restriction indicator light Hydraulic sump filter Inspect filter element for dirt
for hydraulic filter is on and debris. Install new parts as
(indicator light may flash necessary (Group 3260).
momentarily when oil is

Litho in U.S.A.
90 Sys tern Testing JD750 Crawler Bulldozer
9025A-6, Hydraulic System (Analyzer) TM- 1136 (Apr- 79)

TEST AND ADJUSTMENT I

System Relief Valve Test

T66087N

l-Hydraulic Analyzer 8-Black Clip (Negative Post) 1 l-202850 Coupling Adapter

2-Tachometer Generator 7-Red Clip (Positive Post) 12-38952 Hose Assembly 144 in.
3-Thumb Dials (at 030) g-Temperature Sensor (3 858 mm)
4-Tachometer/Temperature Reader 9-System Relief Valve 13-Tachometer Drive Cable
%-Power/RPM Cable 10-202887 Straight Fitting 14-Tachometer Drive

Fig. b-Hydraulic System Analyzer Connection

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90 I
TM- 1136 (Apr- 79) Hydraulic System (Analyzer) 9625/I-7

A CAUTION: Stop the engine. Operate the

hydraulic control levers to release hydrau-
Start the engine and run at fast idle. Heat the hy-
draulic oil to 140 to 150°F (60 to 66°C).
lic pressure in the system. Lower all equipment to
the ground. Loosen the filler plug to release pres- IMPORTANT: For accurate test results, keep the
sure from hydraulic reservoir. temperature of oil between 140 and 150°F (60 and
66%).
Remove platforms or rear bottom guard for access
to blade control valve. NOTE: If the unit is not equipped with hydraulic tilt
dozer or a rear auxiliary function, plugs are installed in
Install fittings (10 and 11, Fig. 3) and hose assembly tilt section of control valve. If unit is equipped with a
(12) into test port of valve. Connect hose assembly to hydraulic tilt angle dozer disconnect hoses for tilt at the
No. 1 coupling adapter on Hydraulic Analyzer (1). control valve. Install caps and plugs on fittings and
hoses. The tilt section is still used to heat the oil and do.
Fasten temperature sensor (8) to the valve return the test.
line as near as possible to valve with a plastic strap.
Connect temperature sensor cable to junction on Ta- To heat the hydraulic oil and check the setting of
chometer/Temperature Reader (4). system relief valve activate a control lever and hold.
Use a circuit (tilt) with no circuit relief valve for a better
NOTE: For good contact put a layer of grease be- test. When the cylinder(s) is at the extended or re-
tween temperature sensor and return line. Put a shop tracted position system pressure will increase until
towel around sensor and line to decrease the effect of released by the system relief valve. This is the setting
outside air temperature. of system relief valve. The flow through the relief valve
will cause the oil to be heated.
install tachometer generator (2) and drive cable (13)
to tachometer drive (14) on engine. Check the system relief valve with tilt cylinder in the
extended and retracted position.
Connect power/rpm cable (5) to tachometer gener-
ator. Connect cable to junction on Tachometer/Tem- System relief valve . . . . .2000 + 175 - 0 psi
perature Reader. (13 800 + 1 200 - 0 kPa)
(138 + 12 - 0 bar)
Turn thumb dials (3) to 030.
Install new parts’& necessary (Group 3260).
Connect red clip (7) of power/rpm cable to positive
post of battery. Connect the black clip (6) to negative
post. The battery is under the operator seat.

Litho in U.S.A.
 90 System Testing JD750 Crawler Bulldozer
9025A-8 Hydraulic System Analyzer TM- 1136 (Apr- 79)

/ Hydraulic Pump Test With the temperature of oil at 140°F (60°C) check the
tilt circuit for any extra leakage. With the blade on the
IMPORTANT: Do the System Relief Valve Test, ground put the tilt cylinder to the extended or retracted
page 9025A-6, before doing this test. If the system position. Let the control lever return to neutral. If there
relief valve is bad it must be changed. If the system is any drift of tilt cylinder in approximately two minutes
relief valve is good do the Hydraulic Pump Test. do the Cylinder Leakage Test, page 9025A-10. Also
this will give the temperature of oil time to stabilize

A CAUTION: Stop the engine. Operate the

hydraulic control levers to release hydrau-
between 140 and 150°F (60 and 66°C).

lic pressure in the system. Lower all equipment to IMPORTANT: For accurate test results keep the
the ground. Loosen the filler plug to release pres- temperature of oil between 140 and 150°F (60 and
sure from hydraulic reservoir. 66%).

Connect Hydraulic Analyzer and Tachometer/Tern- Activate control lever to put tilt cylinder to the ex-
perature Reader as shown in System Relief Valve tended or retracted position. Hold control lever in this
Test, page 9025A-6. position. Slowly increase engine rpm until system
pressure is 1500 psi (10 300 kPa) (103 bar). Write the
Remove the system relief valve (9, Fig. 3) from engine rpm on the Test Record.
control valve. Install the 202842 orifice.
The maximum engine rpm is 1950 with the temper-
ature of oil between 140 and 150°F (60 and 66%) and
HYDRAULIC OIL TEMPERATURE: 140 to 150°F (60 to 66OC) system pressure at 1500 psi (10 300 kPa) (103 bar).
(temperature sensor on valve return line)

ORIFICE USED: 202842, 0.218 in. (5.54 mm) If engine rpm is below 1950 hydraulic pump is good.
(remove system relief valve from If engine rpm is above 1950 do the test again using the
control valve and install orifice)
other circuits. Write the engine rpm for each circuit on
SETTING OF THUMB DIALS: 030 the Test Record. If all engine rpm are above 1950 the
TEST PRESSURE: 1500 psi (10 300 kpa) hydraulic pump is worn. Install new parts as necessary
(103 bar)(inlet to control valve) (Group 3260). If the engine rpm for one circuit is below
MAXIMUM ENGINE RPM: 1950 1950 the hydraulic pump is good. The circuits with
engine rpm above 1950 have a leak. Do the Circuit
I.?!
'56088jl
Leakage Test, page 9025A-9, to find the leakage.
Fig. 4Test Specifications
NOTE: The blade lift cylinders are equipped with
Write the test specifications (Fig. 4) on the Hydraulic bypass poppet valves. The cylinders must be held at
System Test Record. See example of Test Record midstroke to do the test. Hold the cylinders equally to
(Fig. 5). prevent damage to the grille housing.

Start the engine and run at 1500 rpm. Heat the

hydraulic oil to 140°F (60%) using orifice flow.

For orifice flow and to do the test activate a control

lever and hold. Use a circuit (tilt) with no circuit relief
valve for a better test. When the cylinder(s) goes to the
extended or retracted position all flow from pump then
goes through the orifice.

NOTE: If the unit is not equipped with hydraulic tilt

dozer or a rear auxiliary function plugs are installed in
tilt section of control valve. If unit is equipped with a
hydraulic tilt angle dozer disconnect hoses for tilt at the
control valve. install caps and plugs on fittings and
hoses.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Analyzer) 9025A-9

Circuit Leakage Test

HYDRAULIC SYST%M TEST RECORD

HYDRAULIC TEST SPECIFICATIONS: USE ( 0. 21 8-k) ORIFICE, PART NO. -.&2&&&asLfa.
WHILE PRESSURE IS AT /500 PSI ( /03 BAR)
MAXIMUM ENGINE SPEED MUST BE LESSTHAN / 950 RPM.
HYDRAULIC+O,l&TEMPERATUR~ r;iST BE
SYSTEM RELIEF VALVE SETTING: SPEC a000 - o PSI ( ,!38 - o BA

l-Check Condition of Circuits at this Pressure 3-Wade Lift, Indication of a Bad Circuit Relief Valve
2-Tilt Right, Standard Circuit 4-Blade Down, Indication of Leakagb

Fig. 5-Example of Hydraulic System Test Record

(Form M-5107-Stock 5-76)

Use this general procedure to check for leakage in 1. Connect the Hydraulic Analyzer and Tachome-
the circuits. Check each circuit in both directions. Use ter/Temperature Reader as shown in the System Re-
the Test Record to make a record of the test results. lief Valve Test, page 9025A-6.
See example of Test Record (Fig. 5).
2. Install the 202842 orifice as shown in the Hy-
For cycle times, circuit relief valves, etc. see Fig. 6. draulic Pump Test, page 9025A-8.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9025A-10 Hydraulic System (Analyzer) TM- 1136 (Apr-79)

3. Heat the hydraulic oil to 140 to 150°F (60 to 66°C) Cylinder Leakage Test
using orifice flow (same as the Hydraulic Pump Test).
Also operate the other functions so the oil is warm IMPORTANT: The blade. lift cylinders and tilt
when these circuits are checked. cylinders for the hydraulic tilt angle dozer are
equipped with bypass poppet valves. The cylin-
IMPORTANT: For accurate test results, keep the ders must be held at midstroke to do the test. Hold
temperature of the oil between 140 to 150°F (60 and the lift cylinders equally to prevent damage to the
SS’C) for all tests. grille housing.

4. Activate a control lever to put a cylinder(s) to the 1. Put a cylinder to its extended or retracted posi-
retracted or extended position. Hold the control lever in tion.
this position.
2. Disconnect the oil line from cylinder at the end
5. Run the engine just fast enough to get the pres- where cylinder is at the end of its stroke.
sure settings shown on the Test Record. Start at 1500
psi (10 300 kPa) (103 bar) and work down to 250 psi (1 NOTE: Because the tilt cylinders for hydraulic tilt
700 kPa) (17 bar). Write the rpm needed for each angle dozer are used as sing/e acting cylinders only
pressure setting on the Test Record. disconnect hoses from the rod end.

NOTE: The blade /ifi cylinders and tilt cylinders for 3. Put a cap on the line.
the hydraulic tilt angle dozer are equipped with bypass
poppet valves. The cylinders must be he/d at midstroke 4. Start the engine and run at slow idle. While
to do the test. Hold the lift cylinders equally to prevent looking at the open inlet, activate the circuit in the same
damage to the grille housing. direction as in step 1.

6. Check all circuits as in steps 4 and 5. 5. A constant flow of oil is an indication of bad piston
V-packings. Install new parts as necessary (Group
7. See the chart on page 9025A-11. Make a diag- 3260).
nosis of the problem using the chart and Test Record.
6. No flow of oil is an indication of leakage in that
The maximum engine rpm at 1500 psi (10 300 kPa) section of the control valve. Inspect and install new
(103 bar) is 1950 rpm. parts as necessary (Group 3260).

NOTE: With the control lever activated and the cyl-

inder(s) at the end of its stroke all flow from the pump
goes through the orifice. If there is a leak in the
activated circuit some of the flow goes through the
leak. More engine rpm (flow) are then needed as
compensation to get the pressure settings.

Litho in U.S.A.
JD750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Apr- 79) Hydraulic System (Analyzer) 9025A-11

Engine rpm at 1500 psi (10 300 kPa) (103 bar) for
one or more circuits is the same as or less than
specification (1950 rpm). Circuits with engine rpm more than the specification
probably have bad components, Find the circuit with
the lowest engine rpm. Use this circuit as the stan-
dard circuit. Go to block C and/or D to make
between the standard circuit and the

C
All engine rpm in a circuit are more than rpm in Circuit has leakage
the standard circuit. The increase of rpm be-
comes more as the pressure goes up. 1. Do the Cylinder Leakage Test.

2. If used install a new circuit relief valve (Group

3. Do the test again.

If problem is not corrected go to step 4.

4. If used install new anti-cavitation valve (Group

5. Do the test again.

If problem is not corrected, go to step 6.

new section of control valve (Group

There is a sudden increase of engine rpm above Circuit relief valve is bad.
rpm in the standard circuit.
Install new circuit relief valve (Group 3260).

Litho in U.S.A.
90 System 7es ting JD750 Crawler Bulldozer
9025A-12 Hydraulic System (Analyzer) TM- 1136 (Apr- 79)

CIRCUITS

BLADE DOWN (POWER)

2250 + 175 - 0 PSI

AUXILIARY LIFT YES NO (15 500 + 1 200 - 0 kPa)
(155 + 12 - 0 bar)

2250 + 175 - 0 PSI

AUXILIARY DOWN YES NO (15 500 + 1 200 - 0 kpa)
(155 + 12 - 0 bar)

2000 + 175 - 0 PSI (13 800 + 1 200 - 0 kpa) (138 + 12 - 0 bar)

SYSTEM RELIEF VALVE
AT FAST IDLE WITH TEMPERATURE OF OIL BETWEEN 140 and 150°F (60 and 66'C)
6609ON

NOTE: Use cycle times only as a reference. When the performance is not according to the cycle times given, the
service technician must make the decision if the difference is an indication of a failure of some component in the
system.

Fig. 643ulldozer Function Chart

LIST Oi PARTS FOR TESTS

System Relief Valve Test Hydraulic Pump Test

Circuit Leakage Test
1. 202867 Straight Fitting
2. 202850 Coupling Adapter 1. 202867 Straight Fitting
3. 36952 Hose Assembly 144 in. (3 658 mm) 2. 202850 Coupling Adapter
4. Temperature Sensor Cable and Strap 3. 36952 Hose Assembly 144 in. (3 658 mm)
5. Power/RPM Cable 4. 202842 Orifice 0.218 in. (5.54 mm)
6. Tachometer Generator and Drive, Cable 5. Temperature Sensor Cable and Strap
7. D-01080AA Master Hydraulic System Analyzer 6. Power/RPM Cable
8. D-01084AA Tachometer/Temperature Reader 7. Tachometer Generator and Drive Cable
8. D-01080AA Master Hydraulic System Analyzer
9. D-01084AA Tachometer/Temperature Reader

Litho in U.S.A.
 Group 9026
HYDRAULIC SYSTEM

CONTENTS

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-03 Control Circuit Diagram Fold Out ...... 9026-31
Specifications: Pi Relief Valve ..................... 9026-34
Engine Power Test (Proc. 5) . . . . . . . . . . 9026-03 P2 Relief Valve ..................... 9026-35
Engine Speed Adjustment (Proc. 6) . . . . 9026-03 Variable Orifice ..................... 9026-35
Volumetric Efficiency Test (Proc. 8) . . . . 9026-04 Speed Control Valve (P3) ............ 9026-36
Charge Pressure Test (Proc. 9) . . . . . . . 9026-05 Automatic Control Valve 9026-37
Cooling Circuit Test (Case Pressure) Automatic Control Valve Shut off’ ’ : 1 : : : 9026-38
(Proc. 10) . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-05 FNR Valve ......................... 9026-39
High Pressure Relief Valve Test Steering Valve ...................... 9026-40
(Proc. 11) . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-06 Brake Valve ........................ 9026-42
Control Pressure Loss Isolation Oil Cooler Bypass Valve ............. 9026-43
Proc. 14) . . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-06
Control Valve Pl Relief Valve Test Diagnosing Malfunctions ................ 9026-44
(Proc. 17) . . . . . . . . . . . . . . . , . . . . . . . . . . 9026-06 General Drive Check (See the Opera-
Control Valve P2 Relief Valve Test tional Check-Out Proc. Section 9005)
(Proc. 18) . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-07 Diagnostic Flow Charts (Fold Outs):
Variable Orifice Installation Mistracking ......................... 9026-45
(Proc. 19) . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-07 Crawler Will Not Move ............... 9026-46
Variable Orifice Pressure Adjustment Lack of Power and Cycling ........... 9026-47
(Proc. 20) . . . . . . . . . . . . . . . . . . . . . , . . . . 9026-08 Neutral Problems .................... 9026-48
Neutral Band Adjustment (Proc. 21) . . . 9026-08 Overheating ........................ 9026-49
Full Speed Adjustment (Proc. 22) . . . . . 9026-09
Engine Pull Down Adjustment Test Procedures:
(Proc. 23) . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-09 Proc. 01 General Testing Information . 902652
Automatic Control Valve Operational Proc. 02 Transmission, Warm-up . . . . . 9026-61
Check (Pro. 24) . . . . . . . . . . . . . . . . . . . . . 9026-09 Proc. 03 Control Circuit Bleeding . . . . . 9026-62
Accumulator P9 Operational Check Proc. 04 Drain and Flush Hydrostatic
(Proc. 25) . . . . . . . . . . . , . . . . . . . . . . . . . . 9026-10 System . . . . . . _ . . . . . . . _ . . , 9026-64
Steering Valve Stops Adjustment Proc. 05 Engine Power Test
(Proc. 26) . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-10 (Turbo Boost) . . . . . . . . . . . . . 9026-66
FNR and Engine Speed Linkage Proc. 06 Engine Speed (Fast and
and Drag Adj. (Proc. 31) . . . . . . . . . . . . . 9026-10 Slow Idle) . . . . . . . . . . . . . . . . 9026-68
General Information: Proc. 07 Initial Start-up After
Dual Path Hydrostatic Drive System . . . 9026-l 1 Transmission Repair . . . . . . . 9026-70
Proc. 08 Transmission Efficiency Test 9026-72
Theory Of Operation: Proc. 09 Charge Pressure and
Hydrostatic Transmission . . . . . . . . . . . . . 9026-l 2 Vacuum . . . . . . . . . . . . . . . . . . 9026-74
Circuit Diagram Foldout . . . . . . . . . . . . . . 9026-l 5 Proc. 10 Cooling Circuit Test
Charge Pump . . . . . . . . . . . . . . . . . . . . . . . 9026-17 (Case Pressure) . . . . . . . . . . . . 9026-77
Pump Displacement Control Valve . . . . . 9026-18 Proc. 11 High Presure Relief Valve
Motor Displacement Control Valve . . . . 9026-23 Test . . . . . . . . . . . . . . . . . . . . . 9026-78
Manifold Valve Assembly . . . . . . . . . . . . . 9026-24 Proc. 12 Isolate Transmission Charge
Transmission Bypass Valve . . . . . . . . . . . 9026-25 Pressure Loss . . . . . . . . . . . . . 9026-80
Transmission Operating Pressure Valve 9026-26 Proc. 13 Pump Displacement Control
Control Circuit . . . . . . . . . . . . . . . . . . . . . . 9026-27 Valve Neutral Adjustment . . . 9026-83

Continued on next page

T60:9026 701 110184

Litho in U.S.A. (Feb-84) 9026-01 SP-579; TM-l 136, 1137 1164, 1165, 1231, 1250
T76:9026
PO1
100184
 Hydrostatic Sys tern

Test Procedures-Continued
Proc. 14 Isolate Transmission Control Circuit Diagrams (Fold Outs)
Pressure Loss . . . . . . . . . . . . 9026- 85 Transmission Control Circuit ........ 9026-l 15
Proc. 15 Tracking Tests and Transmission Control Circuit
Adjustments . . . . . . . . . . . . . 9026- 87 (Pictorial) . . . . . . . ........ 9026-l 16
Proc. 16 Adjust Transmission Control Hydrostatic Transmission
Valve After Repair . . . . . . . . 9026- SO Schematic ...... ........ 9026-l 19
Proc. 17 Transmission Control Valve Control Linkage Component
Pl Adjustment . . . . . . . . *. . 9026- 91 Location . . . . . . . . ........ 9026-i 20
Proc. 18 Transmission Control Valve Transmission Component
P2 Adjustment . . . . . . . . . . . 9026- 92 Location . . . . . . . . ........ 9026-l 23
Proc. 19 Variable Orifice
Installation . . . . . . . . . . . . . . . 9026- 93 Glossary of Terms . . . . . . . . . . . . ........ 9026-l 25
Proc. 20 Variable Orifice Pressure
Adjustment . . . . . . . . . . . . . . 9026- 94
Proc. 21 FNR Lever Neutral Band
Adjustment P3 . . . . . . . . . . . 9026- 95
Proc. 22 Control Pressure Full Speed
Adjustment . . . . . . . . . . . . . . 9026- 96
Proc. 23 Automatic Control Valve
Adjustment (Engine Pull
Down) (P4) . . . . . . . . . . . . . . 9026- 97
Proc. 24 Automatic Control Valve
Operational Check . . . . . . . . 9026- 99
Proc. 25 Automatic Control Valve
Accumulator Check (PS) . . . 9026-100
Proc. 26 Steering Valve Stop
Adjustment . . . . . . . . . . . . . . 9026-l 01
Proc. 27 Injection Pump and
Transmission Control
Valve Synchronization . . . . . 9026-102
Proc. 28 Steering Linkage Ad-
justment . . . . . . . . . . . . . . . . . 9026-l 06
Prox. 29 Steering Counter-
Rotation Stop Ad-
justment . . . . . . . . . . . . . . . ~. 9026-107
Proc. 30 Return To Neutral Linkage
Adjustment . . . . . . . . a. . . . . 9026-l 08
Proc. 31 FNR Speed Control Lever
Linkage Neutral Adjust-
ment . . , . . . . . . . . . . . . . . . . ~ 9026-109
Proc. 32 Brake Valve Cable
Adjustment . . . . . . . . . . . . . . 9026-l 11
Proc. 33 Automatic Control Valve
Shut-Off Cable Ad-
justment . . . . . . . . . . . . . . . . . 9026-l 12

T60:9026 702 110184

Litho in U.S.A. (Feb-84) 9026-02 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76:9026
PO0mx84
 Hydrostatic Sys tern/Special Tool Specifications

I 1

SPECIAL TOOLS
NOTE: Order tools from your SERVICE-GARDTM Catalog,
unless o thetwise indicated.

Number Name Use

D-01 080AA Master Hydraulic Analyzer Check pressures.

D-01 082AA Hydraulic Analyzer Check pressures.

D-01 083AA Hydrostatic Switching Unit Check several pressures on one

gauge.

D-01 084AA Tachometer/Temperature Reader Check engine rpm and oil

temperature.

D-01 088AA Construction Equipment Accessory Kit Make pressure test connections.

JD-366 Track Restraint Bars Keep the tracks from moving.

JDE-147 Intake Manifold Pressure lest Kit Test intake manifold pressure.

JDT-42 Spring Scale Adjust FNR speed control handle ant

engine speed control handle set
screws.

PROCEDURE 5 - ENGINE POWER TEST

SPECIFICATIONS

Engine rpm . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . fast idle

Turbocharger boost pressure 855, 750,
755, 755A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 to 12psi
(62 to 83 kPa) (0.6 to 0.8 bar)
Turbocharger boost pressure 850, 855 . . . . .12 to 15 psi
(83 to 103 kPa) (0.8 to 1.O bar)

PROCEDURE 6 - ENGINE SPEED

ADJUSTMENT SPECIFICATIONS

Fast idle setting 655, 750, 755,

755A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2280 to 2300 rpm

Fast idle setting 850, 855 . . . . . . e. . . . .1910 to 1950 rpm

.low idle setting (all units) . . . . . . . . . . . .975 to 1025 rpm

Litho in U.S.A. (Feb-84) 9026-03 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
-ix:9026
PO3
100184
 Hydrostatic Sys tern/Special Tool Specifications

PROCEDURE 8 -TRANSMISSION VOLUMET-

RIC EFFICIENCY TEST SPECIFICATIONS

Oil temperature . . . . . . . . . . . . . . . . . . . . . . . . .135 to 160°F

(57 to 71°C)

Engine rpm 655. 850, 755, 755A . . . . ~. . . . .2150 & 10

Engine rpm 850, 855 . . . . . . . . . . . . . . . . . . . . ..1850 -c 10

Forward and reverse system

pressure setting . . . . . . . . . . . . . . ~. . . . . 4900 to 5100 psi
(33 785 to 35 164 kPa) (338 to 352 bar)

Condition of transmission system at following forward and

reverse differential control pressures:

good 850, 855 . . . . . . . . . . . . . . . . . . . . . . . . . .O to 15 psi

(0 to 103 kPa) (0 to 1 .O bar)

good655,750,755,755A . ..~ . . . . . . . . . . . . . Oto14psi

(0 to 96 kPa) (0 to 0.1 bar)

marginal 850, 855 . . . . . . . . . . . . . . . . . . . . . . .16 to 20 psi

(103 to 138 kPa) (1 .O to 1.4 bar)

marginal 655, 750, 755, . . . . . . . . . . . . . . . . . .15 to 19 psi

755A . . . . . . . . . . . . . . . . . .(97 to 131 kPa) (1.0 to 1.3 bar)

bad 850,855 . . . . . . . . . . . . . . . . . . . . . . . . . ..above20 psi

(138 kPa) (1.4 bar)

bad655,750,755,755A .* . . . . . . . . . . . . . . abovelgpsi
(131 kPa) (1.3 bar)

Litho in U.S.A. (Feb-84) 9026-04 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76:90*6
PO4090184
 Hydrostatic System/Special Tools Specifications

PROCEDURE 9 - CHARGE PRESSURE TEST

SPECIFICATIONS

1. Neutral Charge Pressure Test

Engine rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . fast idle
Neutral charge pressure setting . . . . . . . . .260 to 340 psi
(1793 to 2344 kPa) (18 to 23 bar)

2. Operating Charge Pressure Test

Engine rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . fast idle

Operating charge pressure setting . . . . . . .180 to 240 psi
(1241 to 1655 kPa) (12 to 17 bar)

3. Charge Vacuum Inlet Pressure Test

Engine rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . fast idle

Maximum charge vacuum inlet pressure . . . . . . 10 in. Hg.

(34 kPa) (338 mbar)

PROCEDURE 10 - COOLING CIRCUIT (CASE

PRESSURE) TEST SPECIFICATIONS

Oil temperature . . . . . . . . . . . . . . . . . . . . . . . . . 100 to 180°F

(38 to 82°C)

Engine rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . fast idle

Case pressure:

Bypass valve closed at 100°F (38°C) . . . . . . . .5 to 15 psi

(34 to 103 kPa) (0.3 to 1 .O bar)

Bypass valve open at 160 to 180°F

(71 to 82°C) . . . . . . . . . . . . . . . . . . . . . . . . . .25 to 50 psi
(172 to 345 kPa) (1.7 to 3.4 bar)

Litho in U.S.A. 9026-05 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T7h:90*6
PO5100184
 Hydrostatic System/Special Tool Specifications

PROCEDURE II- HIGH PRESSURE RELIEF

VALVE TEST SPECIFICATIONS

Oil temperature . . . . . . . ~. l.. . . . . . . . . . *. . .135 to 160°F

(57 to 71 “C)

Engine rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . fast idle

Forward and reverse system differential

relief valve setting 655, 750,
755, 755A . . . . . . . . . . . . . . . . . . . . . . . . . 6100 to 6500 psi
(42 059 to 44 817 kPa) (420 to 448 bar)

Forward and reverse system differential

relief valve setting 850, 855 . . . . . . . . . . 6300 to 6700 psi
(43344 to 46096 kPa) (434 to 461 bar)

PROCEDURE 14 - TRANSMISSION CONTROL

PRESSURE LOSS ISOLATION
SPECIFICATIONS
Oil temperature . . . . . . . . . . . . . . . . . . ~. . . . . .135 to 160°F
(57 to 71%)

Engine rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . fast idle

P5 and P7 differential control pressures must not be more

than 2 psi (14 kPa) (0.1 bar) apart.

PROCEDURE 17 - TRANSMISSION CONTROL

VALVE OVERPRESSURE RELIEF VALVE (Pl)
ADJUSTMENT SPECIFICATIONS

Enginerpm .I~ . . . . . . . ~.....~ . . . . . . 00 . . . . . ..fastidle

Overpressure relief valve (Pl) setting . . . .280 to 340 psi

(1931 to 2344 kPa) (19 to 23 bar)

Oil temperature *. . a. . . . . . . . . . . . . . . . . . . . 135” to 160°F

(57°C to 71°C)

Litho in U.S.A. (Feb-84) 9026-06 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T769026
PO6
1001*4
 Hydrostatic System/Special Tool Specifications

3OCEDlJRE 18 - TRANSMISSION CONTROL

.ALVE PRESSURE REGULATING VALVE
(P2) ADJUSTMENT SPECIFICATIONS

Engine rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fast Idle

Pressure regulating valve (P2) setting . . . .160 to 200 psi

(1103 to 1379 kPa) (11 to 14 bar)

Oil temperature . . . . . . . . . . . . . . . . . . . . . . . . 135” to 160°F

(57°C to 71 “C)

PROCEDURE 19 - VARIABLE ORIFICE

INSTALLATION ADJUSTMENT
SPECIFICATIONS

Length of variable orifice valve slot . . . . . . . . . . . . . 0.4 in.

(10 mm)

Litho in U.S.A. (Feb-84) 9026-07 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76:90*6
PO7090184
 Hydrostatic Sys tern/Special Tool Specifications

PROCEDURE 20 - VARIABLE ORIFICE

PRESSURE ADJUSTMENT SPECIFICATIONS

Oil temperature . . . . . . . . . . . . . . . . . .135” to 160°F (71°C)

Engine rpm:
Lever against HIGH variable orifice
stop 850, 855 . . . . . . . . . . ~. . . . . . . . . . . . . . . . . .I800 -c 5
Lever against HIGH variable orifice
stop 655, 750, 755. 755A . . . . . . . . . . . . . . . . . . .2100 + 5
Lever against LOW variable orifice stop . . . . . .lOOO + 5

Pi differential control pressure setting:

Lever against HIGH variable orifice stops . . . .50 &- 1 psi
(345 f 7 kPa) (3.45 + 0.07 bar)
Lever against LOW variable orifice stop . . . . .60 -c 1 psi
(414 f 7 kPa) (4.14 + 0.07 bar)

PROCEDURE 21- NEUTRAL BAND

ADJUSTMENT SPECIFICATIONS

Oil temperature . . . . . . . . . . . . . . . . . . . . . . . . .135 to 160°F

(57 to 71°C)

Engine rpm . . . . . . . . . . . s . . . . . . . . . . . . . . . . . . . .slow idle

FNR speed control hand neutral band (A) . .75 to 1.5 in.
(22 to 38 mm)

Litho in U.S.A. (Feb-84) 9026-08 SP-579; TM-1136, 1137, 1164, 1165, 1231, 1250
rw?026PO8
090184
 Hydrostatic System/Special Tool Specifications

‘ROCEDURE 22 - TRANSMISSION CONTROL

ZRESSURE FULL SPEED ADJUSTMENT
( SPECIFICATIONS

Oil temperature . . . . . . . . . . . . . . . . . . . . , . . . .135 to 160°F

(57 to 71°C)
Engine rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . fast idle

P5 and P7 forward differential control

pressure setting 850, 855 . . . . . . . . . . . . . . . . ,134 & 2 psi
(924 + 14 kPa) (9.2 -I- 0.1 bar)
P5 and P7 forward differential control pressure setting 655,
750, 755, 755A . . . . . . . . . . . . . . . . . . . . . . . . . .124 + 2 psi
(854 + 14 kPa) (8.5 t 0.1 bar)

P6 and P8 reverse differential

control pressure setting 850, 855 . . , . . . . . . .134 t 2 psi
(924 t 14 kPa) (9.2 + 0.1 bar)

P6 and P8 reverse differential

control pressure setting 655, 750,
755, 755A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124 F 2 psi
(854 k 14 kPa) (8.5 + 0.1 bar)

PROCEDURE 23 - AUTOMATIC CONTROL

VALVE ADJUSTMENT SPECIFICATIONS
(PULL DOWN)

Oil temperature . . . . . . . . . . . . . . . . . . . . . . . . .135 to 160°F

(57 to 71 “C)

Engine pulldown 655, 750, 755, 755A 1800 to 1850 rpm

Engine pulldown 850, 855 . . . . . . . . . . . . . . .1550 to 1600

PROCEDURE 24 - AUTOMATIC CONTROL

VALVE OPERATIONAL CHECK
SPECIFICATIONS

Oil temperature . . . . . . . _ . . . . . . . . . . . . . . . . .135 to 160°F

(57 to 71 “C)
Engine rpm . . . . . . . . . . . . . . . . . . . . . . . . . fast idle to 1500

drive Check:
The Automatic Control Valve should function at all engine
speeds above 1500 rpm.

Litho in U.S.A. (Feb-84) 9026-09 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T7b;wxPO9
loom4
 Hydrostatic Sys tern/Special Tool Specifications

PROCEDURE 25 - AUTOMATIC CONTROL

VALVE ACCUMULATOR (P9) CHECK
SPECIFICATIONS

Oil temperature . . . . . . . . . . . . . . . . . . . . . . . . .135 to 160°F

(57 to 71 “C)

Engine rpm . . . . . . . . . . . . . . . . . . . . . . . . a. . . . . . . fast idle

P9 Differential control pressure must exceed 100 psi (689

kPa) (7 bar) in 2.5 to 3.5 seconds.

PROCEDURE 26 - STEERING VALVE STOPS

ADJUSTMENT SPECIFICATIONS

Oil temperature . . . . . . . . . . . . . . . . . . . . . . . . .135 to 160°F

(57 to 71°C)

Enginerpm .~~ . . . . . . . . . . ~. . . . . . . . . . . . . . . . ..fastidle

P5 and P7 control pressure setting . . maximum plus l/2

turn of steering valve adjusting screw out

PROCEDURE 31- FNR SPEED CONTROL

LINKAGE NEUTRAL ADJUSTMENT
SPECIFICATIONS

Force required to move FNR speed

control handle . . . . . . . . . . . . . . . . . . . . . . . .6 + 1 lb. force
(27 & 5 N)

Force required to move engine

speedcontrolhandle .D . . . . . . . . . . . . . . . 19&2Ib.force
(85 + 9 N)

Litho in U.S.A. (Feb-84) 9026-l 0 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76;9026
P10090184
 Hydrostatic System/General Operation

DUAL-PATH HYDROSTATIC DRIVE SYSTEM

GENERAL INFORMATION

T4.59158

I-FNR Speed Control Handle 4-Final Drive 7-Right Transmission 10-Engine

P-Transmission Control Valve G-Parking Brake &-Drive Shaft 1 l--Steering Pedals
3-Sprocket 6-Left Transmission g-Splitter Drive 12-Parking Brake Pedal
13-Brake Valve
The dual path hydrostatic drive system consists of left The operator controls dual-path hydrostatic
and right transmissions (6 and 7), transmission control transmission by FNR speed control handle (1)
valve (2), brake valve (13), hydrostatic reservoir, filter, steering pedals (11) or levers, the parking brake pedal
oil cooler and oil cooler bypass valve. (12), and engine speed control handle (not shown).

The hydrostatic transmission drive is infinitely variable The transmission control valve compares operator’s
from 0 to 6.5 mph (0 to 10.5 km/h) in forward or reverse. inputs and work load conditions to control two trans-
missions hydraulically by a circuit of low pressure oil.
Power from splitter drive (9) turns the two drive shafts
(8) which are connected to transmission pumps. Oil The brake vlave (13)‘releases charge pressure to brake
flow generated from pumps turns transmission motors. piston and allows springs to mechanically apply parking
The transmission are two separate, hydrostatic drives brakes (5) when parking brake pedal is pressed down.
controlled by transmission control vlave. One transmis-
sion drives each track.
9AQ;T45915 T60;9026 241 190183

Litho in U.S.A. (Feb-84) 9026-l 1 SP-579; TM-1136, 1137, 1164, 1165, 1231, 125;
TX:9026
P11100184
 Hydrostatic System/Theory of Operation

HYDROSTATIC TRANSMISSION External charge oil flows to the operating pressure

OPERATION valve (45), The operating pressure valve senses both
charge pump pressures. The higher charge pressure
The hydrostatic system can be divided into three moves the valve spool and allows lower charge
circuits: pressure to flow to the brake valve (37) and to the
transmission oil pressure gauge (35). From the brake
a. High pressure circuit (high pressure loop)-used to valve, charge oil flows to the parking brake (10) and
operate the pump and motor. moves the brake piston to disengage the brake
b. Charge pressure circuit (low pressure loop)-used to elements. Charge oil from the brake valve also flows
control the pump and motor servo cylinders, to provide to the bypass valves (46) and moves the spool to close
cooling and for brake operation. the passage between the high and low pressure closed
c. Control pressure circuit - used to control the pump loop. The bypass valves stop the flow of high pressure
and motor displacement control valves. oil from the transmission pump to the transmission
motor by equalizing pressure in both closed loops when
The high pressure circuit consists of the transmission the parking brakes are applied.
pump (44), transmission motor (1 l), bypass valve (46),
high pressure relief valves (51 and 55) and manifold As pressure increases in the high pressure closed loop,
valve assembly shuttle valve (53). high pressure oil (9) moves the shuttle valve spool (53)
and allows charge oil to flow from the low pressure
The charge pressure circuit consists of the charge closed loop to the operating charge relief valve (54) in
pumps (49), checkvalves (57), transmission pump (44), forward or reverse. Excess charge oil opens the
transmission motor (1 l), pump servo cylinder (58) operating charge relief valve and provides cooling for
motor servo cylinder (56), bypass valve (46), manifold the transmission pump and motor. During neutral,
valve assembly shuttle valve (53), operating charge excess charge oil opens the neutral charge reief valve.
relief valve (54), neutral charge relief valve (14), The operating charge relief valve opens at a lower
operating pressure valve (45) brake valve (37) and pressure than the neutral charge relief valve.
parking brake (10).
High pressure oil (9) flows from the tranmsission pump
The control pressure circuit consists of the control (44) to the transmission motor (11). The quantity of high
pump (13) overpressure relief valve (24), variable pressure oil flow to the motor is determined by pump
orifice (27) pressure regulating valve (25), speed speed and swashplate angle. During forward operation,
control valve (23), automatic control valve (21) auto- the bypass valve is closed separating the high and low
matic control valve shut-off valve (22), FNR valve (20) pressure closed loops. High pressure oil also flows to
steering valves (17 and 29), pump displacement control the high pressure relief valves (51 and 55) and shuttle
valve (15) and motor displacement control valve (12). valve (53). During forward operation when the high
pressure side of the closed loop exceeds system
Suction oil (3) flows from the reservoir (30) through four pressure setting, the forward pressure relief valve (51)
filters (31) to the inlet of the charge pumps (49) and opens. All excess oil flows to the low pressure closed
control pump (13). loop. High pressure oil flows around the reverse
pressure relief valve (55) to the shuttle valve.
Charge oil (8) from the charge pumps flows to the low
pressure side of the closed loop to the transmission Pl control oil (7) from the control pump (13) flows to
pump (44) and motor (11) by one of two check valves the transmission control valve (16) inlet port. From the
inlet port, Pl control oil flows to the over pressure relief
(57).
valve (24), variable orifice (27) and automatic control
The second check valve is held closed by high pressure valve (21). P2 control oil (6) from the variable orifice
oil (9) in the high pressure closed loop. Charge oil in flows to the pressure regulating valve (25), speed
the low pressure closed loop also flows to the manifold control valve (23) and automatic control valve. P3
valve assembly (52) and around the bypass valve (46). control oil (5) from the speed control valve flows to the
automatic control valve and automatic control valve
Charge oil also flows through the pump displacement shut off valve (22). P4 control oil (4) from the automatic
control valve (16) and moves the forward servo cylinder control valve flows to the FNR valve (20), steering
piston (58) to increase pump swashplate angle. At the valves (17 and 29) and pump (15) and motor (12)
same time, charge oil flows through the motor displace- displacement control valves. P4 control oil moves the
ment control valve (12) and moves the low speed servo pump and motor displacement control valve spools to
cylinder piston (56) to hold the motor swashplate at the allow charge oil to flow to the pump forward servo
maximum angle. Return oil in the reverse and high cylinder and motor low speed servo cylinder.
speed servo cylinders flows to reservoir (30).

Litho in U.S.A. (Feb-84) 9026-l 2 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T769c’26
PI21001*4
 Hydraulic System

Litho in U.S.A. (Feb-84) 9026-13 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:902b
P13100184
 Hydras ta tic Sys tern

l-Trapped Oil 22-Automatic Control Valve Shutoff Valve 42-From R.H. Transmission Drain Port
2-Reservoir Oil 23-P3 Speed Control Valve 43-From R.H. Transmission Charge Pump
3-Suction Oil 24-Pl Overpressure Relief Valve 44-L.H. Transmission Pump
4-P4 Control Oil 25-P2 Pressure Regulating Valve 45-Transmission Operating Pressure Valve
CP3 Control Oil 28-Right Steering Lever 48-L.H. Transmission Bypass Valve
8-P2 Control Oil 27-Variable Orifice 47-To R.H. Transmission Bypass Valve “BP”
7-Pl Control Oil 28-Variable Orifice Lever Port
B-Charge Oil 28-Right Steering Valve 48-From R.H. Transmission Bypass Valve
8-System Pressure Oil 38-Hydrostatic Reservoir “T” Port
W-Parking Brake 31-Transmission Filters 48-L.H. Transmission Charge Pump
1 i-L.H. Transmission Motor 324il Cooler 58-L.H. Transmission End Cap
12-Motor Displacement Control Valve 33-Oil Cooler Bypass Valve Bl-Forward High Pressure Relief Valve
13--Transmission Control Pump 34-Transmission Temperature Gauge 52-L.H. Transmission Manifold Valve
14-Neutral Charge Relief Valve 38-Transmission Pressure Gauge Assembly
15-Pump Displacement Control Valve 38-To R.H. Transmission Charge Pump 53-Shuttle Valve
l8-Transmission Control Valve 37-Brake Valve %--Operating Charge Relief Valve
l7-Left Steering Valve 38-To Brake Pedal Linkage 55-Reverse High Pressure Relief Valve
18-FNR Speed Control Lever 38-To R.H. Parking Brake %--Low Speed-Servo Cylinder
18-Left Steering Lever $&-From R.H. Transmission Pump Displace- 57-Cheek Valve
2O-FNR Valve ment Control Valve “H” Port CS-Forward Servo Cylinder
PI-Automatic Control Valve 41-To R.H. Transmission Pump Displace-
ment Control Valve “X” Port

Legend for Transmission Hydrostatic Circuits for Left Transmission in Forward Operation

Litho in U.S.A. (Feb-84) 9026-14 T76;9026

PM100184
SP-579; TM-1 138, 1137, 1164, 1165, 1231, 1250
 Hydrostatic Sys tern

CHARGE PUMP OPERATION

A-System Pressure Oil G-From Reservoir M-Splined Connector

D-Charge Pressure Oil H-Transmission Charge Pump N-To Case Drain
C-PI Control Pressure Oil I-Check Valve (2 used) O-Pump End Cap
D-Suction Oil J-lo Motor Displacement Control Valve P-To Pump Displacement Control Valve
E-Return to Reservoir Oil K-Low Pressure Closed Loop Q-Neutral Charge Relief Valve
F-To Transmission Control Valve L-High Pressure Closed Loop R-Transmission Control Pump

Left Transmission Charge Pump and Transmission Control Pump Shown (In Forward Operation)

The charge pump is a gear-type pump driven by the The control pump (R) provides a flow of oil to the
main pump drive shaft. transmission control valve for use in controlling trans-
mission operation.
The neutral charge relief (Q) in the charge pump body,
is a shim adjustable relief valve. In the pump end cap (0), between the charge pump
and closed-loop circuit (K and L) are two check valves
The left-hand transmission charge pump is actually two (I). These are spring loaded ball-type check valves
pumps, the charge pump and control pump. The charge which control make up oil into the closed loop. This oil
pump (H)provides the flow of oil necessary for normal replaces oil lost through leakage and provides for
charge pump functions, the same as the right-hand closed loop cooling oil.
charge pump.

Litho in U.S.A. (Feb-84) 9026-17 SP-579; TM-1136, 1137, 1164, 1165, 1231, 1250
T,b;9c’*6
PI7100184
 I

Hydrostatic Sys tern

PUMP DISPLACEMENT CONTROL VALVE

OPERATION
On the top side of the pump displacement control valve
housing is the shuttle spool. The purpose of the shuttle spool
is to provide proper routing of control pressure oil to the
motor displacement control valve in both forward and
reverse directions.

The swashplate indicator provides a visual means of

determining the angle of the pump swashplate during
transmission operation. It is particularly important for testing
and trouble-shooting the dual-path transmission in service.

bitho in U.S.A. (Feb-84) 9026-I 8 SP-579;TM-1136, 1137, 1164, 1165, 1231, 1250
l-76:9026
P18100184
 Hydrostatic System

The internal operating mechanism within the pump displace-

ment control valve consists of three major links; the spring
arm (l), the spool arm (6), and the feedback arm (3).

The center of the spool arm (6) is connected to the control

valve spool (5) by a low-friction ball (4) and socket joint. The
pivot end of the spool arm rotates on an antifriction bearing
(7) located in the control valve housing by a special screw.
The other end of spool arm is connected to the neutral
adjustment mechanism with centering springs (2) acting
upon each side of the arm.

1 IMPORTANT: Do not adjust linkage except for neutral

adjustment, cleaning or to adjust the
I
spbol arm as described in Group 0360.
Altering the other linkages will disturb l-Spring Arm 5-Valve Spool
P-Centering Springs B-Spool Arm
factory adjustments and cause machine
3-Feedback Arm 7-Antifriction Bearing
control porblems. 4-Low-Friction Ball 8-Steel Link

The spring arm (1) pivots around a cap screw and bushing ’ 8
located in the corner of control valve. The length of spring
arm is extremely critical to the operation of feedback linkage.

The free end of the spring arm is connected to the end of

the neutral adjustment mechanism rod. A steel link (8) is
connected to the spool arm just below the neutral adjust-
ment rod and centering spring ‘(2). The steel link is also
connected to the feedback arm (3).

The feedback arm (3) rotates on a pivot shaft screw into the
control valve housing. This pivot shaft operates the swash-
plate indicator. The feedback arm (3) is connected to the
swashplate feedback link when the control valve is mounted
on the transmission pump.

Litho in U.S.A. (Feb-84) 9026-19 SP-579, TM-l 136, 1137, 1164, 1165, 1231, 1250
T76;9026
PI9100184
 Hydrostatic Sys tern

A-Forward Control Line From F-Pump Swashplate Neutral Position K-Feedback Arm
Transmission Control Valve G-Swashplate and Servo Assembly L-Motor Displacement Control Valve
S-Reverse Control Line From H-Motor Swashplate Maximum Angle M-Forward Control Oil
Transmission Control Valve l-Transmission Motor N-Reverse Control Oil
C-Pump Displacement Control Valve J-Charge Pump Line O-Charge Oil
D-Shuttle Valve P-Return to Reservoir Oil
E-Transmission Pump Q-Control Valve Spool

Transmission Control Circuit - Neutral Phase

The pump displacement control valves (C) and motor The motor displacement control valve spool is held in
displacement control valves (L) are hydraulically con- the left position by a heavy spring. Charge oil to the
trolled by the transmission control valve. Control oil motor displacement control valve (L) is allowed to flow
from the pump displacement control valves also flows to one servo piston of the motor swashplate. The
to the motor displacement control valves. charge oil holds the motor swashplate against the 18”
swashplate stop.
In neutral, the control oil is stopped by the speed
control valve. When no control oil flows to either end
of the pump displacement control valve spool (Q), the
centering springs hold the spool in the center position.
Charge oil (0) flow to the pump servo piston is blocked.

Litho in U.S.A. (Feb-84) 9026-20 SP-579 TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:9026
Pm100184
 Hydrostatic Sys tern

A-Forward Control Line From E-Transmission Pump K-Feedback Arm

Transmision Control Valve F-Pump Swashplate Forward Movement L-Motor Displacement Control Valve
D-Reverse Control Llne To D-Swashplate and Servo Assembly M-Charge Pressure Oil
Transmission Control Valve H-Motor Swashplate Maxlmum Angle N-P4 Control Oil
C-Pump Displacement Control Valve I-Transmission Motor O-Reservoir Oil
D--Shuttle Valve J-Charge Pump Line P-Control Valve Spool

Transmission Control Circuit - Forward Operation - Pump Phase (Increasing Pressure)

In the pump phase, P4 control oil (N) flows from the As the feedback force overcomes the control pressure,
transmission control valve to the pump displacement the valve spool moves back to the closed position, and
control valve (C). The P4 control oil acts upon the charge pump flow to the servos is blocked.
control valve spool (P) shifting it to the open position.
With the spool in the open position, charge pump flow Since the transmissions use variable displacement
(J) is metered out to the upper swashplate servo and pumps and motors, speed increase occurs in two
the swashplate (G) is moved. phases, pump phase and motor phase. As control
pressure increases from zero up to approximately 52
As the swashplate is moving, the feedback arm (K) is psi (359 kPa) (3.6 bar) differential pressure the pump
acting upon the centering springs and the spool arm. is increasing its displacement (increasing swashplate
angle) (F), but the motor swashplate is held at maxi-
The swashplate continues to rotate until the feedback mum angle (H). This phase called the pump phase,
linkage creates enough force upon the control valve controls the crawler to approximately 3 mph (4.8 km/h).
spool to overcome the forward control pressure.

Litho in U.S.A. (Feb-84) 9026-21 SP-579; TM-1136, 1137, 1164, 1165, 1231, 1250
T76:9026
P21loolao
 Hydras ta tic Sys tern

A-Forward Control Line From E-Transmission Pump J-Charge Pump Line

Transmission Control Valve F--Pump Swashplate Maximum K-Feedback Arm
S-Reverse Control Line To Forward Angie L-Motor Displacement Control Valve
Transmission Control Valve G--Swashplate and Servo Assembly M-Charge Pressure Oil
C-Pump Displacement Control Valve H-Motor Swashplate Minimum Angle N-P4 Control Oil
D-Shuttle Valve l-Transmission Motor O-Reservoir Oil

Transmission Control Circuit - Forward Operation - Motor Phase (increasing Pressure)

In the second phase, called motor phase P4 control oil The operator sets transmission speed and thus crawler
(N) pressure increases from approximately 52 psi (359 speed, by the FNR speed control handle. Moving this
kPa) (3.6 bar) (924 kPa) (9.2 bar) to 134 psi differential handle determines control pressure to the transmission
pressure. to set swashplate angle.

This control pressure increase causes the motor swash

plate (G) to decrease its angle (H) and thus decrease
its displacement. In the motor phase, while the motor
is decreasing its displacement, the pump is held at
maximum displacement (F). The reduced displacement
causes the motor to increase its speed in order to utilize
the full pump flow. The motor phase controls the
crawler speed from approximately 3 mph (4.8 km/h)
to 6.5 mph (10.5 km/h).

Litho in U.S.A. (Feb-84) 9026-22 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76;90*b
P22100184
 Hydrostatic System

MOTOR DISPLACEMENT CONTROL VALVE

OPERATION

The internal mechanism of the motor displacement motor control valve, however, adjustment of this
control valve is similar to the pump displacement mechanism controls the exact pressure at which the
control valve. motor swashplate begins to move.

The motor displacement control valve has a threaded The operation of motor displacement control valve is
spring seat which adjusts spring force for making motor very similar to the pump displacement control valve we
phasing adjustment. This adjustment is similar to the saw earlier. However, the motor swashplate begins to
neutral adjustment on the pump control valve. On the move only after the pump swashplate is at its maximum
angle. Tb0;90Zb
367080383

Litho in U.S.A. (Feb-84) 9026-23 SP-579 TM-l 136, 1137, 1164, 1165, 1231, 1250
T,b:9026
P23100184
.-
 Hydrostatic Sys tern

MANIFOLD VALVE ASSEMBLY

OPERATION

A-System Pressure Oil E-Low Pressure Closed- H-Shuttle Valve J-Reverse Operation (except
B-Charge Pressure Oil LOOP l-Operating Charge 666/706 series right side
C-Reservoir Oil F-To Motor Case Drain Relief Valve forward operation)
D-High Pressure Closed- G-High Pressure Relief Valve K-Neutral Operation
Loop (2 used) L-Closed-Loop (Equaliz-
ed Pressure)
Manifold Valve Assembly (Reverse Operation)

The manifold valve contains two pilot operated high and is returned to the reservoir. During periods of
pressure relief valves (G), a shuttle valve (H) and an operation when the transmission pump is in neutral, the
operating charge relief valve (I). The pressure relief shuttle valve is closed. Excess oil flow from the charge
valves serve to prevent sustained abnormal pressure pump is directed to the cooling circuit by the neutral
surges in the closed loop by dumping oil from the high charge relief valve in the charge pump. When operating
pressure side during heavy loads. in this condition, cooling flow is not admitted to the
motor because it is at rest.
The shuttle valve functions to establish a circuit
between the closed-loop passage that is at low The manifold valve assembly has three passages
pressure (E) and the operating charge relief valve. The which come from the motor end cap.
operating charge relief valve limits charge pressure to
180 to 240 psi (1 200 to 1 700 kPa) (12 to 17 bar). The two larger passages (D and E) are from the two
Excess charge oil (6) flow is dumped by the operating sides of the closed-loop circuit between the pump and
charge relief valve. This excess oil provides for cooling motor. The third, smaller, passage (F) goes to the
of the hydrostatic transmission. In neutral the shuttle crankcase of the motor for crankcase cooling flow.
valve is spring centered to close off flow from the
closed-loop to the operating charge relief valve. The two larger passages are subjected to high pres-
sure; one during forward operation and one during
Excess cooling oil from the operating relief valve enters reverse operation. The two high pressure relief valves
the motor case (F), then flows to the pump case. In this on each side of the manifold valve assembly have their
way the charge pump cooling oil is circulated through relief setting at 6000 psi (46 000 kPa) (460 bar)
each of the hydraulic elements in series to aid in differential pressure between the two sides of the
cooling. The cooling oil then exits from the pump case closed-loop.

Litho in U.S.A. (Feb-84) 9026-24 SP-579 TM-1 136, 1137, 1164, 1165, 1231, 1250
TX.9026
PP4
100184
 Hydrostatic System

TRANSMISSION BYPASS VALVE OPERATION

A-Normal Operation G-To Pump M-Inlet (BP) Port R-To Motor

B-Parking Brake Applied H-Bypass Piston N-To Left Transmission B-Cross Section of
C-High Pressure Oil I--Spring Bypass Valve Pump End Cap
B-Charge Pressure Oil J-Return (T) Port O-From Brake Valve T-Return to Reservoir
E-Reservoir Oil K-To Reservoir P-Bypass Valve Through Applied Brake
F-From Pump L-From Left Transmis- G-From Motor Valve
sion Bypass Valve

The transmission bypass valve basically consists of a When the operator presses the brake pedal to apply
valve and piston inside of a cast housing. The purpose the parking brake, or if the engine is stopped, charge
of the transmission bypass valve is to interrupt the flow pressure to the bypass valves is interrupted (B). The
of high pressure oil (C) from the pump (F) to the motor inlet ports (M) of the bypass valves are then opened
(R) when the parking brakes are applied or charge to drain back to the reservoir.
pressure decreases.
The loss of charge pressure on the underside of the
The internal passages route the closed-loop circuit to piston allows the springs to push the piston and valve
the bypass valve. There are also two external ports. down. This connects the high and low pressure sides
The port on the spring side (J) is connected to the of the closed-loop equalizing the pressure in both sides
reservoir and the spring side port on the other transmis- of the closed loop and interrupting pump flow to the
sion bypass valve. The piston side port (M) is con- motor.
nected to the brake valve and the piston side port on
the other transmission bypass valve. This prevents pressure from building between the
pump to motor. Motor rotation stops and motor output
During normal operation (A) charge pressure (D) goes torque drops to nearly zero since the closed-loop
through the brake valve and then out to the bypass pressure is equalized.
valves. The charge pressure acts upon the underside
of the bypass piston (H) to overcome the spring (I) force As the bypass valves interrupt transmission output
on the top of piston. The difference in forces actuate rotation and torque, the parking brakes are being
the bypass valve (P) to the closed position. applied on the input shafts to the final drives. This
provides a means of positively stopping power flow
With the piston and valve closed, the high and low from the engine to the tracks with a minimum of heat
pressure sides of the pump and motor closed-loop are build-up.
kept separated.

Litho in U.S.A. (Feb-84) 9026-25 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:9026
P251001*4
 Hydrostatic Sys tern

rTRANSMISSION OPERATING PRESSURE

VALVE OPERATION
The transmission operating pressure valve is used to provide
a means of sensing both transmission charge pressures with
one pressure gauge on the dash. The valve spool (A) is
moved by the higher transmission charge pressure (F) and
the lower charge pressure (E) is allowed to pass to the brake
valve and the transmission oil pressure gauge on the dash.

A-Valve Spool
B-Charge Pressure From
Right Transmission
C-Charge Pressure From
Left Transmission
D-Lowest Charge Pressure
(Left Transmission)
To Brake
Valve and Oil Pressure
Gauge on Dash
E-Charge Pressure Oil
F-Higher Charge Pressure Oil

Transmission Operating Pressure

Valve.

Litho in U.S.A. (Feb-84) 9026-26 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T7W026PZ6090184
 Hydrostatic System

TRANSMISSION CONTROL CIRCUIT

OPERATION

A-P1 Control Oil G-Hydrostatic Reservoir M-P2 Pressure Regulating Valve S-Right Steering Valve
S-P2 Control Oil H-Transmission Filter N-Speed Control Valve T-Right Transmission
C-P3 Control Oil l-Control Pump O-Speed Control Cam U-Left Transmission
D-P4 Control Oil J-P1 Overpressure Relief Valve P-FNR Speed Control Handle V-Left Steering Valve
E-Suction Oil K-Transmission Control Valve Q-Automatic Control Valve
F-Reservoir Oil L-Vairable Orifice R-FNR Valve
Transmission Control Valve Block Diagram

The control system for the dual-path transmission The transmission control valve is a pressure regulating
centers around the transmission control valve. This component. Basically there is no flow of oil through the
control valve is what makes two separate hydrostatic control lines to the transmissions, since the transmis-
drives work together as one transmission. sion control valve controls the pump and motor
displacement control valves by pressure. The only flow
The control system actually consists of five major that actually goes from the transmission control valve
components. The transmission control valve (K) is the to the pump and motor displacement control valves is
main component and the displacement control valves used to fill the small space behind the pump and motor
on the right and left transmission pumps and motors displacement control valve spools as they are moved.
make up the rest of the system. Some flow is also needed to make up for any leakages
past the spools.
The transmissions are controlled by the pressure that
the transmission control valve directs to the pump and The operator’s FNR speed control handle (P) is
motor displacement control valves. The higher the connected to the speed control valve. The position of
pressure, the higher the speed. The speed control the forward and reverse control handle determines the
valve (N) controls the pressure to the pump and motor control pressure the speed control valve will provide
control valves. the control circuit.

Litho in U.S.A. (Feb-84) 9026-27 SP-579; TM-1136, 1137, 1164, 1165, 1231, 1250
TX.:9026
P271001m
 Hydrostatic Sys tern

The transmission control valve consists of nine valve

components. These are the speed control valve (N), the
FNR valve (R), the Pl overpressure relief valve (J), the P2
pressure regulating valve (M), the automatic control valve
(Q), the automatic control valve shut-off valve, the variable
orifice (L), and two steering valves (S and V).

Litho in U.S.A. (Feb-84) 9026-28 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T7WOZbPa 090184
 Hydraulic Sys tern

Litho in U.S.A. (Feb-84) 9026-29 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:90Zb
P29110184
 Hydrostatic Sys tern

Suction oil (8) flows from the reservoir (24) through reduce engine load. When machine load decreases,
filters to the control pump (25). The control pump the automatic control valve increases transmissior
provides a flow of oil to the transmission control valve output speed back to the original setting (made by the
for use in hydraulically controlling the pump and motor operator). The automatic control valve prevents engine
displacement control valves of the left and right rpm from being pulled down below approximately 1550
transmissions. rpm.

Pl control oil (2) from the control pump flows past the P4 control oil (5) flows from the automatic control valve
Pl overpressure relief valve (18) into the variable to the FNR valve (11). The FNR valve directs control
orifice (20) and automatic control valve (12). The Pl oil to either the forward or reverse control circuits. The
overpressure relief valve prevents damage of the FNR valve and the speed control valve are connected
control pump in case of a restriction that closes the together. Movement of the FNR speed control handle
variable orifice. causes the speed control valve to set P3 control
pressure and the FNR valve to select transmission
The control pump flow going through the variable direction.
orifice creates a Pl - P2 differential pressure. The size
of the variable orifice is set by the engine speed setting P4 control oil (5) from the FNR valve is then routed to
made by the operator. The Pl - P2 differential pres- the two steering valves (10 and 16) through either the
sure is sensed at the automatic control valve and acts forward or reverse lines (depending on the position of
as a signal of how engine rpm is being affected by the the FNR valve). One line carries forward control
machine’s work load. pressure (P5 and P7) and is pressurized for forward
operation and the other line carries reverse control
The P2 pressure regulating valve (17) sets P2 pressure. pressure (P6 and P8). These lines go to the pump
Since very little flow of control oil is needed to maintain displacement control valves (22 and 27). Two more
control pressure to the transmissions, the P2 pressure lines go from the pump displacement control valve to
regulating valve is almost always open to relieve the motor displacement control valve (23 and 26). The
excess control oil to sump. shuttle valve (21) is used to direct P4 control oil to one
end of the motor displacement control valve spool. The
After passing the P2 pressure regulating valve, P2 steering valves individually control the control pres-
control oil (3) enters the speed control valve (15). The sures going to the left and right transmissions. For
speed control valve is controlled by the operator to set steering, the operator actuates the right or left steering
transmission output speed. The position of the cam pedal (or lever). The steering valve then reduces the
acting against the speed control valve plunger deter- control pressure to that transmission to reduce its
mines P3 control oil. output speed. The greater the pedal (or lever) move-
ment the slower that transmission will turn. The other
P3 control oil (4) enters the automatic control valve. transmission is unaffected while one transmission is
The automatic control valve regulates P3 as necessary being slowed.
to maintain engine rpm in the maximum horsepower
output range. When machine work load reaches the By fully depressing one of the steering pedals (or
point where the engine rpm is being pulled down too pullling one of the levers) the one transmission will go
far, the automatic control valve reduces P4 control into reverse to give the machine counter-rotation.
pressure to slow down transmission output speed and Counter-rotation is the reversal of one transmission
with the other one still in forward.

l-Charge Oil 12-Automatic Control Valve 22-Pump Displacement Control Valve

2-Pl Control Oil (Normal Operation) (Motor Phase - Pump Swashplate
3-P2 Control Oil 13-Automatic Control Valve Shut-Off Maximum Forward Angle)
4-P3 Control Oil Valve (Normal Operation) 23-Motor Displacement Control Valve
6-P4 Control Oil W-Rate Control Orifice (Motor Phase - Motor Swashplate
6-P9 Control Oil l-peed Control Valve (Full Forward) Minimum Angle)
7-Reservoir Oil %--Right Steering Valve (Forward - ScGReservoir
6-Suction Oil No Steering) 26-Control Pump
g--Equalized Pressure Oil 17-P2 Pressure Regulating Valve 26-Motor Displacement Control Valve
W-Left Steering Valve (Forward l&P1 Overpressure Relief Valve (Neutral Phase - Motor Swashplate
Full Steering) W-Orifice Maximum Angle)
1 I-FNR Valve (Full Forward) 29-Variable Orifice 27-Pump Displacement Control Valve
21-Shuttle Valve (Forward) (Neutral Phase - Pump Swashplate
Neutral Position)

Legend for Transmission Control Circuit

Litho in U.S.A. (Feb-84) 9026-30 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:902b
P30100184
 Hydrostatic Sys tern

l-Hydrostatic Reservoir e-Speed Control Valve 17-P8 Pressure Test 23-Left Steering Valve
P-Hydrostatic Filters 10-FNR Speed Control Handle Port (Reverse) 24-Transmission
3-ControI Pump ll-P3 Pressure Test Port l&P7 Pressure Test Control Valve
4-Pl Overpressure 12-Automatic Control Valve Port (Forward) 25-Pl Control Oil
Relief Valve Shut-Off Valve W-Right Transmission 26-P2 Control Oil
6-Pl Pressure Test Port 13-Automatic Control Valve 26-Left Transmission 27-P3 Control Oil
6-Variable Orifice 14-P4 Pressure Test Port 21-P6 Pressure Test 28-P4 Control Oil
?-P2 Pressure Test Port 15-FNR Valve Port (Reverse) 29-Suction Oil
8-P2 Pressure Regu- 16-Right Steering Valve 22-P5 Pressure Test 36-Reservoir Oil
lating Valve Port (Forward)
Transmission Control Valve Box Diagram with Test Ports

The control pressures at any point in the system are P5 (22) and P6 (21) are the forward and reverse control
all numbered. The identification of these pressures is pressures for the left transmission (20). P7 (18) and P8
particularly important during testing and troubleshoot- (17) are the forward and reverse control pressures for
ing. Pi through P9 indicate the control pressures of the right transmission (19). P9 is an internal pressure
each point inside the transmission control valve. of the automatic control valve (13).

There are nine pressure test points in the transmission With the machine in neutral P5, P6, P7, and P8 are at
control valve (24). Pl (5) is the pressure between the the same pressure. However in forward or reverse two
outlet of the control pump (3) and variable orifice (6). lines, P5 and P7 for forward, or P6 and P8 for reverse,
P2 (7) is the pressure after the variable orifice, which will be pressurized at any one time. In forward P6 and
is set by the P2 pressure regulating valve (8). P3 (11) P8 will be at return pressure. In reverse P5 and P7 will
is the pressure set by the speed control valve (9). P4 be at return pressure.
(14) is the pressure after the automatic control valve
(13).

Litho in U.S.A. (Feb-84) 9026-33 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:%‘Zb
P33100184
 Hydrostatic Sys tern

Each of the nine test points on the transmission control valve

are plugged. Beside each plug is a number cast into the
housing to identify the control pressure at that test location.

A-P6 Pressure Test Port F-P3 Pressure Test Port

S-P5 Pressure Test Port G-P2 Pressure Test Port
C-P9 Pressure Test Port H-P7 Pressure Test Port
D-P1 Pressure Test Port I-P8 Pressure Test Port
E-P4 Pressure Test Port

OVERPRESSURE RELIEF VALVE

OPERATION
The PI overpressure relief valve (E) directly senses the
pressure of control pump flow (A) to the variable orifice (B)
and automatic control valve. The Pl overpressure relief
valve opens only when the variable orifice is blocked or
plugged. When Pl reaches its pressure setting, the control
flow must be relieved to sump to prevent damage to the
control pump.

Do not confuse the Pl overpressure relief valve and the P2

pressure regulating valve. The Pl overpressure relief valve
protects the control pump from possible excess Pl pressure
caused by a blocked variable orifice. But the P2 pressure
regulating valve is used to set the pressure of the P2 flow
entering the speed control valve.

A-From Control Pump E-PI Overpressure Relief

B-To Variable Orifice Valve
C-From Speed Control F-P1 Control Oil
Valve G-Reservoir Oil
D-To Reservoir

Litho in U.S.A. (Feb-84) 9026-34 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T7W02bP34100~84
 Hydrostatic Sys tern

VARIABLE ORIFICE OPERATION

The variable orifice lever (E) on the transmission control
valve is connected to the fuel injection pump cable, so when
the engine speed is changed, the orifice (G) size is also
changed. This arrangement provides a constant pressure
differential signal to the automatic control valve at any
engine speed setting, allowing the automatic control valve
to react the same for all engine speed settings made by the
operator.

The variable orifice valve housing (D) has a square window

(C) on its side. The variable orifice valve (F) has a small
orifice in the side of its hollow end. The orifice in the valve
lines up with the window in the valve housing. By rotating
the valve, the length of the orifice that is uncovered in the
window varies. This changing orifice is the variable orifice.
Oil from the control pump (A) flows into the window in the
valve housing and through the orifice. It then flows out the
end of the variable orifice valve to the P2 pressure regulating
valve (B).

A-From Control Pump E-Variable Orifice Lever

B-To Pressure Regulating F-Valve Spool
and Speed Control Valve G-Valve Spool Orifice
G-Valve Housing Window H-P1 Control Oil
D-Valve Housing I -P2 Control Oil

P2 PRESSURE REGULATING VALVE

OPERATION
Any control pump flow not being used to maintain control
pressure must be relieved. A pressure regulating valve (E)
placed between the variable orifice and speed control valve
relieves the excess flow to the reservoir. Since very little flow
is needed in the control circuit (B), the pressure regulating
valve is almost always open, with oil flowing to the reservoir
(D). That means the pressure regulating valve sets the
maximum pressure of the oil entering the speed control
valve. This relief valve is called the P2 pressure regulating
valve.

A-From Variable Orifice D-To Reservoir

B-To Speed Control Valve E-P2 Pressure
C-From Overpressure Re- Regulating Valve
lief Valve F-P2 Control Oil
G-Reservoir Oil
I

Litho in U.S.A. (Feb-84) 9026-35 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76;90*6
P35100184
 Hydrostatic Sys tern

SPEED CONTROL VALVE OPERATION

The speed control valve is used to set P3 control oil pressure
to the pump and motor displacement control valves. The
speed control valve varies control pressure depending on
the speed set by the operator.
P2 control oil (J) from the P2 pressure regulating valve (E)
flows around the speed control valve (C) to the automatic
control valve (H).

When the operator moves the FNR speed control handle,

the speed control cam (G) also moves which moves the
speed control plunger (F), spring, and speed control valve
(C) upward.

When the speed control valve opens, P3 control oil (K) flows
to the rate control orifice (A), automatic control valve (I), and
speed control plunger.

The rate control orifice restricts P3 control oil flow to the top
of the speed control valve spool. The orifice dampens the
movement of the speed control valve spool.

The amount of upward movement of speed control valve

determines the P3 control oil pressure to the automatic
control valve. The P3 control oil pressure determines crawler
speed.

P3 control oil around the speed control plunger helps to

move the plunger and reduces cam wear.

When the cam moves to neutral position, the speed control

valve spool moves down opening a passage to reservoir (D)
for excess P3 control oil.

A-P3 Rate Control Orifice G-Speed Control Cam

B-Adjusting Screw H-To Automatic Control Valve
C-Speed Control Valve I-To Automatic Control Valve
D-To Reservoir J-P2 Control Oil
E-From P2 Pressure Regu- K-P3 Control Oil
lating Valve L-Reservoir Oil
F-Speed Control Plunger

Speed Control Valve Operation During Full Speed Forward

Litho in U.S.A. (Feb-84) 9026-36 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T7W026P36100184
 Hydrostatic Sys tern

AUTOMATIC CONTROL VALVE OPERATION

The automatic control valve is a special type of pressure
regulating valve. Instead of being controlled mechanically,
the automatic control valve is controlled by the pressure
differential created across an orifice. The pressure before
the orifice is Pl. The pressure after the orifice is P2.

When the engine speed increases, Pl pressure increases

resulting from increased control pump flow. Pl control oil
(Q) from the control pump (F) flows to the bottom of piston
(L). P2 pressure is held constant by the P2 pressure
regulating valve. P2 control oil (R) from the P2 pressure
regulating valve (E) flows to the top of piston and the bottom
of accumulator piston (G). When Pl pressure increases and
P2 pressure remains constant, Pl control oil moves the
piston upward and opens the control valve (N). At the same
time, P2 control oil moves the accumulator piston upward.
The PI and P2 pressure and accumulator piston spring (H)
hold the control valve open. The accumulator piston helps
to maintain constant P2 pressure and removes surges in the
P2 circuit.

As the control valve moves upward, the passage to reservoir

(B) is closed and P3 control oil (S) from the speed control
valve (D) flows to the FNR valve. P3 control oil that flows
past the control valve becomes P4 control oil (T).

P4 control oil pressure increases as the control valve moves A-Control Valve Spring L-Piston
upward to increase crawler speed to the setting of FNR B-To Reservoir M-To FNR Valve
speed control handle. P4 control oil flows to the FNR valve C-To Shut-Off Valve N-Control Valve Spool
D-From Speed Control Valve O-Control Valve Sleeve
(M), top of control valve, inside of accumulator piston, and
E-From Pressure Regulating P-Adjusting Screw
shut-off valve (C). Valve Q-P1 Control Oil
F-From Control Pump R-P2 Control Oil
When Pl pressure varies, the control valve, P4 pressure and
G-Accumulator Piston S-P3 Control Oil
speed of transmission will automatically vary to match work H-Accumulator Spring T-P4 Control Oil
load and engine speed. I-Orifice (2 used) U-P9 Control Oil
J-Filter V-Reservoir Oil
When the engine speed decreases, Pl pressure decreases K-Piston Sleeve
resulting from decreased control pump flow. A decrease in
Pl pressure with P2 pressure constant allows the piston to Automatic Control Valve Operation with P4
move downward. At the same time, P2 control oil moves the Increasing Pressure.

accumulator piston downward. The Pl and P2 pressure and

control valve spring (A) close the control valve.

As the control valve moves downward, the P3 control oil

passage from the speed control valve is closed and some
P4 control oil flows to reservoir. P4 control oil pressure to
the FNR valve decreases as the control valve moves
downward to decrease crawler speed.

While P4 control oil pressure decreases, P9 control oil (U)

from the accumulator flows through the orifice (I) into the
P4 control oil circuit. The accumulator orifice provides a slow
md smooth decrease in P4 pressure.

Litho in U.S.A. (Feb-84) 9026-37 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:90*6
P37100184
 Hydrostatic Sys tern

AUTOMATIC CONTROL VALVE SHUT-OFF

VALVE OPERATION
The shut-off valve (D) allows P3 control oil (F) from the
speed control valve (G) to bypass the automatic control
valve (C) and flow directly to the FNR valve (J) during cold
weather transmission oil warm-up. Cold oil flowing through
the variable orifice and automatic control valve causes slow
valve operation which may stall the engine.

The shut-off valve is also used to isolate the automatic

control valve from the control circuit when diagnosing
problems.
During normal operation, the shut-off valve is closed. P3
control oil must flow through the automatic control valve
before flowing to the FNR valve. In normal operation, P3
control oil will bypass the shut-off valve.

During bypass operation, the shut-off valve is open. The

return passage for P4 control oil (N) to reservoir (F) is closed
and the oil becomes trapped (a). P3 control oil from the
speed control valve flows directly to the P4 control oil
passage and then to the FNR valve bypassing the automatic
control valve.

During bypass operation, the automatic control valve does - 141

not control the P4 pressure. The operator must control the
speed manually.

A-Normal Operation I-From Control Pump

B-Bypass Operation J-To FNR Valve
C-Automatic Control Valve K-P1 Control Oil
B-Shut-Off Valve L-P2 Control Oil
E-Shut-Off Valve Plug M-P3 Control Oil
F-To Reservoir N-P4 Control Oil
G-From Speed Control Valve O-P9 Control Oil
H-From Pressure Regulating P-Reservoir Oil
Valve G-Trapped Oil

Litho in U.S.A. (Feb-84) 9026-38 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76:9026
P381001*4
 Hydrostatic Sys tern

I 1

FNR VALVE OPERATION

The FNR valve (C) controls the direction of transmission
operation by directing P4 control oil (G) to either the forward
or reverse passages of steering valves. The FNR valve lever
and speed control valve lever are connected to the control
shaft (D).

During forward operation, the control shaft moves the FNR

valve upward. P4 control oil from the automatic control valve
(B) flows around the FNR valve to the steering valves
forward line (F). Reservoir oil (H) from the steering valves
reverse line (E) flows to reservoir.

During reverse oepration, the control shaft moves the FNR

valve downward. P4 control oil flows to the steering valves
reverse line. Reservoir oil from the steering valves forward
line flows to reservoir.

When the FNR valve is in neutral, the P4 control oil passage

to the steering valves forward and reverse line is closed. All
oil from the steering valves flows to reservoir.

A-To Reservoir E-From Steering Valves Reverse Lines

B-From Automatic F-To Steering Valves Forward Lines
Control Valve G-P4 Control Oil
C-FNR Valve H-Reservoir Oil
D-Control Shaft

FNR Valve Operation in Forward

Litho in U.S.A. (Feb-84) 9026-39 SP579; TM-1136, 1137, 1164, 1165, 1231, 1250
776;9026
P39100184
 Hydrostatic Sys tern

STEERING VALVE OPERATION

A-NO Steering Forward F-Steering Valve Spool M-To FNR Valve (Reservoir) R--Steering Valve Spring
Operation G-Steering Valve Sleeve N-To Reservoir S-Steering Valve Lever
B-No Steering Reverse H-P5 Pressure Test Port O-To Pump Displacement Co- T-From Pump Displacement
Operation I- P5 Orifice trol Valve Forward Lines Control Valve Forward Lines
C-P4 Control Oil J-From FNR Valve P-Steering Valve Stop U-To Pump Displacemenl
D-Reservoir Oil K-P6 Pressure Test Port G--From Pump Displacement Control Valve Reverse
E-Adjusting Screw Stop L-P6 Orifice Control Valve Reverse Lines Lines

Left Steering Valve

The steering valve (F) is a spool type valve that moves Return oil (D) from the reverse lines of the pump and
inside a stationary sleeve (G). The oil flow between the motor displacement control valves (Q) is connected to
steering valve and sleeve determines no steering, full reservoir.
steering and counter-rotation steering conditions.
During a “no steer” reverse operation (B), P4 control
During no steering forward operation (A), the steering oil flows through the center passage of the steering
valve linkage is held against the stop (E) by spring valve to the reverse lines of the pump and motor
pressure (R). displacement control valves (U).

P4 control oil flows around the grooved area on the Return oil from the forward lines of the pump and motor
valve spool through the forward line to the left pump displacement control valves (T) flows to reservoir
and motor displacement control valves (0). At a given through the steering valve and FNR valve.
transmission speed, P5 pressure is equal to P4
pressure.

Litho in U.S.A. (Feb-84) 9026-40 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76’9026
Pm100184
 Hydras ta tic Sys tern

A-Full Stopped H-P6 Orifice N-Steering Valve T-From Pump Displace-

Forward Operation I-To FNR Valve (Reservoir) Groove ment Control Valve
B-Counter-Rotation Operation J-To Reservoir O-Slight Steering Forward Lines
C-Steering Valve Spool K-To Pump Displacement P-P4 Control Oil U-Steering Valve Stop
D-P5 Pressure Test Port Control Valve Forward Lines G-Equalized Pressure V-To Pump Displacement
E-P5 Orifice L-From Pump Displacement Oil Control Valve Reverse
F-From FNR Valve Control Valve Reverse Lines R-Reservoir Oil Lines
G-P6 Pressure Test Port M-Full Steering S-Counter-Rotation

Left Steering Valve

During steering operation (A), the steering valve (C) to the forward lines of pump and motor displacement
moves downward. As the steering valve moves down, control valves. The P5 oil to reservoir passage is also
a small groove (N) in the valve is opened. P4 control closed. P5 oil flows through the middle of valve to the
oil (P) flows through the P5 orifice (E) and becomes P5 reverse lines (V) of the pump and motor displacement
pressure oil (D). As P5 pressure oil flows across the control valves.
groove in the steering spool to P6 pressure oil, the two
pressures become closer to being equal which results
Return oil (R) from the forward lines (T) of the pump
in the track slowing down.
and motor displacement control valves flows around
When the steering pedal is against the steering stop, the steering valve spool. From the steering valve,
the groove is open far enough to allow P5 and P6 return oil flows to reservoir through the P6 orifice (H)
pressure to become equal (M). Since the pressure (Q) and FNR valve (I).
is equal in both the forward and reverse pump displace-
ment control valve lines (K and L) the track stops Since no P5 control oil flows to reservoir, the P5
moving. pressure in the reverse lines is equal tp P4 pressure.
The forward lines are at reservoir pressure. The reverse
During counter-rotation operation (B), the steering speed of left transmission is the same as forward speed
pedal is at full travel position. The steering valve moves of right transmission and the unit will counter-rotate.
down against the stop (U) and closes the passage (S)

Litho in U.S.A. (Feb-84) 9026-41 SP-579 TM-l 136. 1137, 1164, 1165, 1231, 1250
T76;9026
P41100184
I---.
 Hydrostatic Sys tern

r
BRAKE VALVE OPERATION
The brake valve controls the parking brakes. Any time there
is a loss of charge pressure, the brakes are automatically
applied by the brake valve.

The brake valve consists of the safety check valve (D), the
brake poppet valve (E), the shuttle valve (B), and the manual
brake release pump valve (A).

The safety check valve operates as a differential pressure

valve. Without charge pressure, this valve is held off its seat
by a coil spring. This allows both outlet circuits to return oil
to sump and neutralizes the systems. With charge pressure,
this safety valve is forced against its seat, and restricts the
two outlet circuits from the sump.

The brake poppet valve and check ball are held in place by
spring pressure. Application of the brake pedal will move the
check ball off its seat (G). This will allow both outlet circuits A-Manual Brake Release H-Brake Pedal Linkage
to dump oil around the check ball and back to sump. Pump Valve I-Outlet to Parking Brakes
B-Shuttle Valve J-Outlet to Transmission
The shuttle valve directs pressure oil to one or both outlet C--Charge Pressure Inlet Bypass Valves
circuits, depending upon its position in the bore. In the D--Safety Check Valve K-Charge Oil
E-Brake Poppet Valve L-Trapped Oil
position pictured, oil is directed to both outlets. When this
F-Outlet to Reservoir M-Reservoir Oil
valve shuttles to the spring end of its bore, it directs pressure G-Release Seat
oil only to the parking brakes.
Brake Valve During Normal Operation
The manual pump valve is used for machine down situations
only. This pump forces oil through the shuttle valve and to
the parking brakes. Pump pressure will release the brakes
and allow the machine to be moved.

Litho in U.S.A. (Feb-84) 9026-42 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T7W026P42090184
 Hydrostatic Systern

1
OIL COOLER BYPASS VALVE OPERATION

The oil cooler bypass valve provides a means of quickly

warming up the transmission oil after machine start up.

The bypass valve prevents transmission oil from entering the

cooler until the oil has reached 146°F (63°C). The bypass
also relieves cooling flow from the crankcases directly to the
reservoir in case the oil cooler becomes plugged.

There are small passages (H) in the spool from center of

valve bore-to the thermostatic end. The passage provides
a small flow of case oil to the thermostat (F) so that the
thermostat will sense the temperature of case oil.

The operation of the oil cooler bypass valve is basically

similar to that of a water thermostat in an engine. When the
transmission case cooling flow reaches approximately
146°F (63X), the thermostat expands, opening the valve.

As case oil temperature rises, the valve opens further until

Iit reaches the open position, which allows full case cooling
,oil to flow around the valve and out to the oil cooler (J). A-Hot Oil G-Relief Spring
E-Cooled Oil H-Spool Passage
IReturn flow (I) from the cooler goes around the lower land
C-From Crankcase I-From Oil Cooler
Iof the valve and returns to the reservoir (D). On the 800 D-To Reservoir J-To Oil Cooler
,
Series, some oil is always returned to the reservoir when the E-Valve Spool K--Spring
Ibypass valve is fully open. F-Thermostat L-Temperature Sending
Unlt

IIfthe oil cooler becomes plugged, the pressure overcomes

1the relief spring (G) and closes the valve. With the valve
Islosed, case flow returns directly to the reservoir protecting
1the case seals and oil cooler from excessive pressure
IDuildup.

The operator has a gauge on the dash that indicates

1Yansmission oil temperature. The sending unit (L) for the
!gauge is located in the case oil inlet to the bypass valve. The
!sending unit is connected to the dash gauge by a mercury
I ine.

F;IRh67Q;UJ%A.136, 1164j=Mb@i91231, 1250 9026-43

 Hydrostatic System/Diagnosing Malfunctions

DIAGNOSING MALFUNCTIONS:

This Section is divided into four areas: 3-TEST PROCEDURES . . . . . . . . . . . . . . . . 9026-51

l-GENERAL DRIVE CHECK. (See The If the particular problem is not diagnosed in the flow
Operational Check-Out Procedure- chart stage, the Diagnostic Flow Charts will lead you
Section 9005.) to a more detailed test procedure. These test proce-
2-DIAGNOSTIC FLOW CHARTS. dures are listed on the following page:
3-TEST PROCEDURES
4-SUMMARY OF TEST PROCEDURES
l-GENERAL DRIVE CHECK . . . . . . . . . . . . _ 9005 SPECS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9026-03
This is an operational check-out procedure to be used Use this section for a quick reference to the specifica-
when a customer complaint is unknown. This check tions that are used in the Test Procedures.
should be the first step in diagnosing a machine
problem. It should also be used after a repair to insure
that all problems have been corrected and the unit is
ready to return to the customer.

This Driving Check is done without the use of tools or

test equipment. It is a “From The Operators Seat” type
test. It will lead you to a problem area and a specific
DIAGNOSTIC FLOW CHART.

2-DIAGNOSTIC FLOW CHARTS

These are logical sequences to follow for a general
problem area. These charts stress diagnosing “From
The Operators Seat”using the indicators that are
already on the machine.

To use the Diagnostic Flow Charts, the customer

problem must be catagorized into one of the following
areas:
-Mistracking Complaints . . . . . . . . . . . . . . . 9026-45
-Crawler will not move complaints . . . . . 9026-46
-Lack of power or cycling complaints . . . . 9026-47
-Neutral complaints . . . . . . . . . . . . . . . . . . 9026-48
-Overheating complaints . . . . ~. . . . . . . . . . 9026-49

For the related Diagnostic Flow Chart, see the page

number listed adjacent to the complaint area.

With these five Diagnostic Flow Charts, most problems

can be solved with a minimum amount of diagnostic
time and equipment.

If the problem cannot be solved at the Flow Chart

Stage, more in depth test procedures are also used.

T60:9026 460 191283

Litho in U.S.A. (Feb-84) 9026-44 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76:9026
P44100184
 Hydrostatic Sys tern

Procedure Title Page

1 General Testing Information .............................................. 9026- 52

2 Transmission,Warm-up .................................................. 9026- 61
3 Control Circuit Bleeding .................................................. 9026- 62
4 Drain and Flush Hysrostatic System ....................................... 9026- 64
5 Engine Power Test (Turbo Boost) ......................................... 9026- 66
6 Engine Speed (Fast and Slow Idle) ........................................ 9026- 68
7 Initial Start-Up After Transmission Repair ................................... 9026- 70
8 Transmission Efficiency Test ............................................. 9026- 72
9 Charge Pressure and Vacuum ............................................ 9026- 74
10 Cooling Circuit Test (Case Pressure) ...................................... 9026- 77
11 High Pressure Relief Valve Test .......................................... 9026- 79
12 isolate Transmission Charge Pressure Loss ................................ 9026- 80
13 Pump Displacement Control Valve Neutral Adjustment ....................... 9026- 83
14 Isolate Transmission Control Pressure Loss ................................ 9026- 85
15 Tracking Tests and Adjustments .......................................... 9026- 87
16 Adjust Transmission Control Valve After Repair ............................. 9026- 90
17 Transmission Control Valve Pl Adjustment ................................. 9026- 91
18 Transmission Control Valve P2 Adjustment ................................. 9026- 92
19 Variable Orifice Installation ............................................... 9026- 93
20 Variable Orifice Pressure Adjustment ...................................... 9026- 94
21 FNR Lever Neutral Band Adjustment (P3) .................................. 9026- 95
22 Control Pressure Full Speed Adjustement .................................. 9026- 96
23 Automatic Control Valve Adjustment
(Engine Pulldown) (P4) ................................................... 9026- 97
24 Automatic Control Valve Operational Check ................................ 9026-99
25 Automatic Control Valve Accumulator Check (P9) ........................... 9026-100
26 Steering Valve Stop Adjustment ........................................... 9026-l 01
27 Injection Pump and Transmission Control
Valve Synchronization ................................................... 9026-l 02
28 Steering Linkage Adjustment ............................................. 9026-l 06
29 Steering Counter-Rotation Stop Adjustment ................................ 9026-107
30 Return To Neutral Linkage Adjustment ..................................... 9026-108
31 FNR Speed Control Lever Linkage Neutral
Adjustment ............................................................. 9026-109
32 Brake Valve Cable Adjustment ............................................ 9026-l 11
33 Automatic Control Valve Shut-Off Cable Adjustment ......................... 9026-l 12

T60;9026 461 lOOli

Litho in U.S.A. (Feb-84) 9026-51 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76;9026
61 100184
 Hydrostatic Sys tern

PROCEDURE 1 - TEST PORTS, ADJUST-

MENTS, COMPONENT LOCATION AND TEST
HOOK-UP

A-Left-Hand Transmission I-Pump Servo Cylinder-Pressurized P-Forward System Pressure Relief Valve
B-Charge Vacuum Test Port in Reverse G-Motor Servo Cylinder-Pressurized at
C-Pump Servo Cylinder-Pressurized J-Motor Displacement Control High Speed (Motor Phase)
in Forward Valve Phasing-Turn Clockwise to R-Servo Cylinder Stop (ll”)-Adjust “C”
D-Right-Hand Transmission Decrease Track Speed-Turn Mistrack in Pump Phase Only-Turn
E-Case Pressure Test Port Counterclockwise to Increase Track Clockwise to Increase Speed of Slow
F-Neutral Charge Pressure Test Port Speed Track
G-Pump Displacement Control K-Transmission Control Bleed Screw S-Operating Charge Pressure Test Port
Valve Phasing-Adjusts “9 L-Forward System Pressure Test Port T-Reverse System Pressure Relief Valve
Mistrack in Pump Phase Only- M-Reverse System Pressure Test Port U-Pump Full Speed Stops (18’) in Front
Turn Clockwise to Increase N-Motor Servo Cylinder-Pressurized Cover - Turn Clockwise to Decrease
Reverse Speed-Turn Counterclock- at Low Speed (Pump Phase) Track Speed - Never Turn Stops
wise to Increase Forward Speed O-Servo Cylinder Stop (7”).Adjusts Counterclockwise
H-Neutral Charge Pressure Relief “C” Mistrack at Full Speed Only-
Valve Turn Clockwise to Decrease Speed of
Fast Track

Fig. l-850, 855 Transmission Test Ports and Adjustments

Litho in U.S.A. (Feb-84) 9026-52 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
TX;9026
P52mom4
 Hydrostatic Sys tern

l-Left-Hand Transmission +-Servo Cylinder Stop (lC)-Adjust “C” Mistrack in Pump

2-Right Hand Transmission Phase Only-Turn Clockwise to Increase Speed of Slow
3-Pump Displacement Control Valve Phasing-Adjusts “S” Track
Mistrack in Pump Phase Only-Turn Clockwise to In- ICI-Reverse System Pressure Relief Valve
crease Forward Speed-Turn counterclockwise to In- 1 l-Forward System Pressure Test Port
crease Reverse Speed 12-Reverse System Pressure Test Port
4-Pump Servo Cylinder-Pressurized in Forward 13-Operating Charge Pressure Test Port
5-Pump Full Speed Stop (18”) in Front Cover-Turn Clock- W-Forward System Pressure Relief Valve
wise to Decrease Track Speed-NEVER Turn Stops 15-Motor Displacement Control Valve Phasing-Turn
Counterclockwise Clockwise to Decrease Track Speed-Turn Counter-
6-Motor Servo Cylinder-Pressurized (Pump Phase) clockwise to Increase Track Speed
7-Servo Cylinder Stop (7%“)-Adjusts “C” Mistrack at Full 16-Transmission Control Bleed Screw
Speed Only-Turn Clockwise to Decrease Speed of Fast 17-Pump Servo Cylinder-Pressurized in Reverse
Track 16-Neutral Charge Pressure Test Port
&Motor Servo Cylinder-Pressurized at High Speed (Motor W-Case Pressure Test Port
Phase) PO--Operating Charge Pressure Relief Valve
21-Neutral Charge Pressure Relief Valve

Fig 2-665, 750, 755, 755A Crawler Loader Transmission Test Ports And Adjustments

9AQ;T80390 T60:9026 452 290983

Litho in U.S.A. 902643 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T7W026P53100184
 Hydrostatic Sys tern

l-Reverse Direction 7-P9 Test Port Plug l&-Flight Steering 19-High Variable Orifice
Lever Stop Screw 8-Pl Test Port Plug Valve Lever Stop Screw
2-Forward Direction 9-Automatic Control 15-P7 Test Port Plug PO-Right Steering Valve
Lever Stop Screw Valve Cartridge 16-P8 Test Port Plug Bore Plug
3-FNR Speed Control Lever 1 O-Automatic Control 17-Automatic Control Pl-Drain Port
4-P6 Test Port Plug Valve Adjustment Valve Variable 22-Automatic Control Valve
5-P5 Test Port Plug 1 i-P4 Test Port Plug Orifice Lever Accumulator Piston Bore
6-Left Steering 12-P3 Test Port Plug is--Low Variable Orifice Plug
Valve Lever 13-P2 Test Port Plug Stop Screw 23-Left Steering Valve
Bore Plug

Fig. 3-Transmission Control Valve

9AQ;TB0209 Tb0;9025 153 191283

Litho in U.S.A. (Feb-84) 9026-54 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76;9026
P54100184
 Hydrostatic Sys tern

l-P2 Regulating Valve 3-Automatic Valve

Control Valve S-Left Steering Valve 7-Pl Relief Valve
2-P3 Neutral Band Adjustment Pull Down Adjustment Stop Screw %--Right Steering Valve
4-FNR Valve Bore Plug &-Automatic Control Valve Stop Screw
Shut-Off Valve

Fig 4-Transmission Control Valve

9AQ;T58230 T60;9026 454 290983

Litho in U.S.A. (Feb-84) 9026-55 TM-1136, 1164, 1165, 1231, 1250

T76;9026
P55100184
 Hydrostatic Sys tern

DIAGNOSTIC EQUIPMENT

To properly test and diagnose the hydrostatic transmis-

sion circuits, it is helpful to have the following equip-
ment (Fig. 5):

1. Hydrostic Analyser
2. Hydraulic System Analyser
3. Hydrostatic Switching Box
4. Tachometer, Temperature Reader

Many times througout the test procedures, transmis-

sion control pressures are measured. They are meas-
ured as differential pressures with a tolerance of f 1
psi. To obtain these pressures with this type of
accuracy, one high accuracy gauge is used in conjuc-
tion with the hydrostatic switching box.

1-liydrostic Analyzer
2-Hydraulic Analyzer
3-Hydrostatic Switching Box
4-Tach. Temp. Reader

The switching box allows up to four pressures to be Fig. 5Transmission Test Equipment
“switched” and read on one gauge. This eliminates
gauge error that would be present if four different
gauges were used.

The switching box consists of three switching valves

A, B, C. Each switching valve can be switched to route
oil from one of two inputs (female quick couplers) to
one output marked “Gauge Port” (male quick coupler).

A
CAUTION:
The switching box is designed for pres-
sures of 3000 psi ( kW ( bar) or
lower. DO NOT use in the high pressure
circuit of the transmissions.

l-Switching Valve A
2-Switching Valve B
3-Switch Valve C

9AQ:T45968 T46013 T60;9026 455 290983

Litho in U.S.A. (Feb-84) 9026-56 TM-1136, 1164, 1165, 1231, 1250

T76;90*b
P56momI
 Hydrostatic Sys tern

Use the following procedure to monitor two different

pressures.

NOTE: For this example, the P4 and P6 differential

pressure will be determined. However, this
procedure can be used when comparing any
two pressures.

1. Remove appropriate test port plugs and install male

quick couplers-For this example-P4 and P6 ports on
the transmission control valve.

2. Connect hoses from P4 and P6 on the control valve

to the two inputs on the switching box (1) and (2).

3. Connect a hose from gauge port A (3) on switch box

to the O-300 psi (O-21 bar) gauge quick coupler (4) in
the hydrostatic analyzer.

4. To read pressures, start unit and switch the switch-

ing valve between the two inputs recording P4 and P6
pressures. Subtract the two pressures to obtain the
P4-P6 differential pressure

Example: P4 Pressure= 136 psi

P6 Pressure=12 psi
Differential= 124 psi

1. No. 1 Input
2. No. 2 Input
3. Gauge Port
4. Gauge Connector
5. O-300 psi (0.21 bar)
high accuracy gauge

9AQ;T45964 T48;9026 456 290983

Litho in U.S.A. (Feb-84) 9026-57 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
TX;9026
P57100184
 Hydrostatic Sys tern

Use the following procedure to monitor four pressures

on one gauge:

For this example, P5, P6, P7 P8 will be monitored on

one gauge to obtain the P5 and P6 differential pressure
and the P7 and P8 differential pressure.

459821

1. No. 1 input 4. No. 4 Input 7. Gauge Port A 10. Gauge Connector

2. No. 2 Input 5. No. 5 Input 8. Gauge Port B 11. O-300 psi (O-21 bar)
3. No. 3 input 6. No. 6 Input 9. Gauge Port C High Accuracy Gauge

1. Remove P5, P6, P7 and P8 Test Plugs and install 3. Connect a hose from gauge port A (7) to input (3)
male quick couplers. and another hose from gauge port C (9) to input (4).

2. Connect hoses from these quick couplers on the 4. Connect a hose from gauge port B (8) to gauge
control valve to the switching box as follows: connector (10).

P5-No. 1 input (1) Switching valves 1 and 3 control the inputs to switching
PG-No. 2 input (2) valve 2. Switching valve 2 controls the output to the
P7-No. 5 input (5) pressure gauge.
P8-No. 6 input (6)

9AQ:T45982 T60;9026 457 191283

Litho in U.S.A. (Feb-84) 902648 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
TX;9026
P5B
100184
 Hydrostatic Sys tern

5. To read P5, P6 and P7, P8 differential pressure, run

unit and:

a. Put switching Valve 2 Pointer towards input No.

(3) and move switching Valve No. 1 between
inputs (1) and (2) recording P5 and P6
pressures.

b. Put switching Valve 2 Pointer towards input No

4 and move switching Valve No. 3 between input
(5) and (6) recording P7 and P8 pressures.

c. Calculate P5 and P6 differential pressure:

Example P5 = 136
Minus P6=12
Differential= 124
Calculate P7 and P8
Differential Pressure
P7 . . . . . . . . . . 136
P8 . . . . . . . . . . 12
Differential= 124

SYSTEM PRESSURE
(Closed Loop
Pressure)

A
CAUTION: Pressure spikes in the transmis-
sion closed loop can approach 10,000 psi.
(68,950 kPa) (690 bar). Use only the recom-
mended hoses and fittings when checking
transmission system pressures. DO NOT System Pressure 655, 750, 755, 755A
USE THE SWITCHING BOX.
A-Forward System Pressure
B-Reverse System Pressure
1. Connect the two special high pressure hoses No.
C-Forward System Relief Valve
36953T3 to the forward system pressure test ports on D-Reverse System Relief Valve
both transmission.

A
CAUTION: DO NOT use quick couplers in
the transmission system pressure test
port.

2. Connect the hoses to the two 10,000 psi (68950

kPa) (690 bar) pressure gauges on the hydrostaic
analyzer, (Special high pressure male quick couplers
on the backside of the analyzer).

3. This hook-up will monitor forward system pressure

on both transmissions.

System Pressure 850/855

4. For reverse, connect the high pressure test hoses
to the reserve system test ports. A-Forward System Pressure
B-Reverse System Pressure
C-Forward System Relief Valve
D-Reverse System Relief Valve

9AQ;T95884, T95899 T60;9026 458 191283

Litho in U.S.A. (Feb-84) 9026-59 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T769l2b
P591oom4
 Hydrostatic Sys tern

TACHOMETER/TEMPERATURE READER IN-

STALLATION

Engine rpm and oil temperature are very critical in most

hydrostatic tests. Therefore, it is absolutely necessary to
install the sensors in the same locations to insure accurate
and comparable tests.

1. Install tachometer drive cable (A) from D-01 084AA

Tachometer/Temperature Reader into tachometer drive.
Connect tachometer drive cable to tachometer generator
(W.

2. Connect power/rpm cable (E) to tachometer generator.

3. Clean area and apply grease between temperature

sensor (I) and transmission filter (J). Install temperature
sensor on transmission filter using a plastic cable tie or tape.
Put a shop towel around sensor and filter to reduce effect
of outside temperature.

4. Connect power/rpm cable (E) and temperature sensor

cable(F) to tachometer/temperature reader (H). Turn thumb
dials (G) to 030.

5. Connect power/rpm cable clips (C and D) to battery or

other convenient 12-24 V source.

A-Tachometer Drive Cable F-Temperature Sensor Cable

B-Tachometer Generator G-Thumb Dials (At 030)
C-Black Clip (Negative) H-Tachometer/Temperature
D-Red Clip (Positive) Reader
E-Power/RPM Cable l-Temperature Sensor
J-Transmission Filter
 Hydrostatic Sys tern

‘ROCEDURE 2-TRANSMISSION WARM-UP

For many transmission tests and adjustments, the oil must

be heated to 135-160°F. This can be done by either
operating the machine until transmission temperature on
dash gauge is in middle of green zone or by doing the
following shop procedure:

1. Monitor transmission oil temperature at filter can.

2. Install track restraint bars in both tracks.

NOTE: Track frame cover plates must be removed and

reins tailed after testing.

3. Disconnect the brake pressure hose (A). Put cap (B) and
(C) on brake valve fitting. Tie the hose in an upward position
and loosely cap.

4. Run engine at fast idle and slowly move FNR lever

forward approximately l/3 speed. If the engine cycles, move
FNR lever slightly toward neutral until cycling stops. Run in
this condition until temperature reaches 135-I 60°F.

9AQ;T95895, T88487, T87735 T60;9026 400 191283

Litho in U.S.A. (Feb-84) 9026-6 1 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76;902b
P61100184
 Hydrostatic System

PROCEDURE 3-TRANSMISSION CON-

TROL CIRCUIT BLEEDING

Many erratic control complaint can be caused by air

trapped somewhere in the control circuit.

In many cases this air can be bled out by opening the

bleed screws 3 turns (A) on Motor Displacement
control valves and operating unit for several minutes.

A
CAUTION: Operating unit with bleed
screws open will cause the unit to respond
very slowly to FNR lever movement.

If air remains in system, additional bleeding is required.

Follow these steps:

1. Disconnect the Return-To-Neutral cable from the

lever in the left console and push down the emergency
brake pedal. This will permit full FNR lever movement
without track movement.

2. With unit running at low idle and bleed screws open,

hold FNR lever full forward and reverse for approxi-
mately one minute each. During this time, also press
steering pedals (levers) into counter rotate and release
several times. Repeat Step 2 several times.

3. Tighten bleed screws and reconnect the return to

neutral cable. Operate unit to be certain all air has been
bled from circuit.

Older 750’s and 755’s prior to S/N 283491 are more

difficult to bleed. A special plastic bleed harness is
required to thoroughly bleed these units reference TM
Section 0399.

Connect bleed harness (1) to P5 and P7 for forward

bleeding and to P6 and P8 for reverse. Drop the single
hose end of the harness into the reservoir. Bleed by
repeating the previous Steps 2 and 3 in this procedure. 9AQ;T87684, T87738 T60;9026 401 191283

bitho in U.S.A. (Feb-84) 9026-62 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76xQbP62100184
 Hydrostatic Sys tern

Bleed Harness Connected (Serial No.

The following short bleed procedure should be used when

the transmission oil filters or vacuum switches have been
changed.

Start and run unit at idle in neutral for 2 minutes.

NOTE: DO NOTmove lever out of neutral or air will circulate

into the control lines and valves.

9AQ;T52796 T60;9026 402 191283

Litho in U.S.A. 9026-63 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76;9026
P63100184
 . Hydt-os ta tic Sys tern

PROCEDURE 4-DRAIN & FLUSH

This procedure should be followed when the transmis-

sion oil has been contaminated with noncompatable
fluids such as water or severely contaminated with
particles such as dirt or metal particles.

Most of the particle contamination in reservoir, trans-

mission, and oil cooler is filtered out before it damages
the charge pump, closed loop, or control circuit.

NOT&:
Any SAE 10 weight CD,SE engine oil can be
used as a flushing fluid. Small amounts of oil
remaining after flushing will mix with hydro-
static fluid.

1. Drain the reservoir and both transmission cases.

Leave drain plugs out at this time.

2. Disconnect the cooler lines at the cooler and drain

lines and cooler.

3. Disconnect injection pump solenoid and crank

engine for 3 seconds. This will drain charge pump
suction lines

4. Drain the control valve by removing the “T” plug on

the rear of the valve.

9AQ;T87742, T87744 T60;9026 403 191283

Litho in U.S.A. (Feb-84) 9026-64 W-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
TX;9026
PM100184
 Hydrostatic Sys tern

Drain the brake system by disconnecting the brake lines

. the rear of the transverse case.

j. Follow Start-Up Procedure 7.

I

9AQ;T87757 Tb0;9026 404 200983

1
I

Litho in U.S.A. (Feb-84) 9026-65 SP-579;TM-1136,1137,1164,1165,1231,1250

T7W026PbS100184
 Hydrostatic Sys tern

PROCEDURE 5-TEST ENGINE POWER

(TURBO BOOST CHECK)

This procedure is used to determine if the power output of

an engine is within an acceptable range. It is not intended
to provide an exact horsepower reading.

In this test, intake manifold pressure is monitored when

engine is being lugged to the rpm at which maximum
horsepower is developed. Manifold pressure is an indication
of the amount of fuel being consumed which is a good
indication of horsepower.

Before making an engine power check, do the following:

(A) Clean or replace primary air filter.
(B) Install new fuel filters.
(C) Check Injection pump static timing.
(D) Variefy high idle setting. (See Procedure 6.)

1. In order to provide a steady load for the engine, install

the track restraint bars in both tracks and cap the brakes.
(See Procedure 2.)

2. To monitor intake manifold pressure, install a O-30 psi

(O-207 kPa) (O-2 bar) pressure gauge at starting aid fitting
in intake manifold (A).

For the remainder of this test, make sure engine is at normal

operating temperature.

3. Pull the Automatic Control valve shut-off handle up and

slowly move the FNR lever forward. Lug the engine to 1800
rpm 850/855 or 2100 rpm 655, 750, 755A.

9AQ;T88487, T95889 T60;9026 405 191283

Litho in U.S.A. (Feb-84) 9026-66 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76;9026
Pbb100184
 Hydrostatic Sys tern

1. Operate in this lugged down condition for 15 seconds and

record the highest pressure obtained. The pressure will
1 climb slowly to a peak. Repeat Step 4 several times.

5. The highest pressure should be:

85w855 . . . . . . 12-15 psi (83-103 kpa) (0.0801.0 bar)

655/750/755A . . . .9-12 psi (62-83 kPa) (0.6-0.8 bar)

6. If the pressure is low, check the following possible causes

for low engine power. (See Diagnosing Malfunctions in
Group 9010)

A. Incorrect timing

!3. Improper fuel

C. Fuel starvation, plugged filters or restricted line

T60:9026 406 200983

Litho in U.S.A. 9026-67 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:90*6
P67100184
 Hydrostatic Systern

PROCEDURE 6-ADJUST ENGINE SPEED

It is very important that engine speed be set to specification

as engine speed is the basis from which the transmission
automatic control valve functions. If high idle is as little as
50 rpm below Spec, there will be a noticeable affect on the
performance of the crawler.

1. Disconnect the engine speed control cable from the

injection pump lever and make sure lever rotates freely
and contacts stop screws

1. Injection Pump Lever 4. Injection Pump

2. Speed Control Cable 5. Low Idle Override
3. High Idle Stop 6. Low Idle Stop

ENGINE SPEED ADJUSTMENT

655, 750, 755, 755A

2. Install tach and heat engine to operating temperature.

qotate lever fully to the rear (front on 850/855) so it contacts
nigh speed stop screw. The rpm should be:
655, 750, 755, 755A _. . . . ~. . . . . . . . . . . . .2280-2300
850/855 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 O-l 950

9AQ;T45976, T60;9026 407 190983

bitho in U.S.A. (Feb-84) 9026-68 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T763026
P6S
100184
 Hydrostatic Sys tern

Back out the low idle or override screw (5) to make sure
.ne low idle stop screw (6) in the injection pump cover is
being contacted.

1. Speed Control Cable 4. High Idle Stop Screw

2. Low Idle Stop Screw 5. High Idle Stop Screw Cap
3. Injection Pump Lever 6. Fuel Injection Pump

Engine Speed Adjusment

650/655
4. Rotate lever forward until the low idle stop screw in the
pump cover is contacted. The rpm should be:

655, 750, 755A, 8501855 . . . . . . . . . . .975-1025 rpm

5. With the injection pump lever held against the low idle
stop screw, (6) adjust the low idle override screw (5) until
the engine speed begins to increase. At this point, back off
l/2 turn.

Whenever either the high or low idle stops are adjusted,

check the injection pump to control valve synchronization.
(See Procedure 28A.)

9AQ;T60280 Tb0;9026 408 200983

Litho in U.S.A. (Feb-84) 90.26-69 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
TV:9026
P69100184
 Hydrostatic Sys tern

PROCEDURE 74NITIAL START-UP AFTER

TRANSMISSION REPAIR

This procedure must be followed any time repairs require

draining the oil from the transmission cases or charge pump
suction lines. If just the reservoir is drained no start-up
procedure is required.

If the transmission has been removed from the crawler, fill

the pump and motor cases through the pump case drain port
prior to putting transmission back in unit.

After installing transmission, use the following steps to

insure proper initial start-up:

1. Remove filters and fill charge pump suction lines. Rein-

stall filters. The suction lines are the center ports that filters
screw on to. Fill reservoir to proper level.

2. Disconnect the injection pump shut-off solenoid and

crank the engine with starter until charge pressure gauge
on dash reads 30 psi (205 kPa) (2 bar) for 5 seconds.

NOTE: DO NOT operate starter for more than 20 seconds

at a time. Wait at least 2 minutes between cranking
attempts.

3. Recheck oil level in reservoir and add oil if required.

Leave fill plug loose to allow air to escape.

4. Reconnect injection pump solenoid. Lock parking brake

and run engine in neutral at low idle for 5 minutes. This will
allow the system to fill properly. Monitor reservoir oil level.

NOTE: It is normal for the charge pressure to fluctuate

during initial running. However, if at any time the
dash gauge drops and remains in red zone for more
than 5 seconds, shut off engine and determine
cause. (See Crawler Won’t Move chart)

9AQ;T8?764 T60;9026 409 200983

Litho in U.S.A. (Feb-84) 9026-70 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76:9026
P70100184
 Hydrostatic Sys tern

Disconnect the return to neutral cable under L.H. shift

;onsole. With unit in Neutral, Emergency brake locked down,
run engine fast idle. Move FNR lever slightly into Forward
and hold for 30 seconds. Do this several times gradually
increasing lever movement until full speed is reached. This
will fill and bleed the servo cans.

5. Bleed the transmission control circuit for the final step of

initial start-up. (See Procedure 3).

9AQ:T87738 T60;9026 410 200983

Litho in U.S.A. (Feb-84) 9026-71 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76:9026
P71100184
 Hydras ta tic Systern

PROCEDURE 8-TRANSMISSION
EFFICIENCY TEST

In this test we determine the amount of transmission

internal leakage by recording the amount of oil the
transmission pump must deliver to maintain 5000 psi
33786-35165 kPa (338-352 bar) closed loop pressure.
5000 psi is used because relief valves are not open and
any flow denotes internal leakage.

Pump flow is determined by swash plate angle which

is regulated by control pressure. A low control pressure
to maintain 5000 psi (33786-35165 kPa) (329-352 bar)
means there is very little leakage. A high control
pressure reading means higher internal leakage.

A difference in efficiency between forward and reverse

indicates leakage at components that are directional-
(such as; high pressure relief valves, or other high
pressure manifold components). This difference is also
due to the displacement control valve adjustment not
being exactly centered.

IMPORTANT: To perfom this test, the transmission

oil must be at the proper tempera-
ture, -135”--160°F
(See Procedure 2)

The following must be monitored:

Transmission oil temperature-(Procedure 1) A-Forward System Pressure C-Forward System Relief
&Reverse System Pressure Valve
Engine rpm-(Procedure 1)
D-Reverse System Relief
P5, P6, P7, P8 Control pressure-(Procedure 1) Valve
Forward and reverse system pressure-(Procedure
1) System Pressure 655, 750, 755, 755A

Pull out the Automatic Control Valve Shut-off handle

on left console to prevent the automatic control valve
from operating during this test.

With the track restraint bars installed (see Procedure

2), run engine at:
2150rpm . . . . . . . . . . . . ...655.750.755.755A
1850 rpm . . . . _. . . . . . . ~. . . . . . . . . . . . .850/855

The efficiency check is performed on one transmission

at a time.

1. To test the RH Transmission, neutralize the LH

Transmission by pushing steering pedal or pulling lever
to the dead-track position. A-Forward System Pressure C-Forward System Relief
S-Reverse System Pressure Valve
D-Reverse System Relief
2. While monitoring Forward System Pressure, ease
Valve
the FNR lever slowly into forward until a system
pressure of 4900-5100 psi (33786-35165 kPa) (338- System Pressure 8501855
352 bar) is obtained. At this point record P7, P8 Control
Pressures. 9AQ;T95884, T95899 T60;9026 411 191283 1

Litho in U.S.A. (Feb-84) 9028-72 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T7.%9026
P72100184
 Hydrostatic Sys tern

IMPORTANT: Engine speed should not drop below

2050 rpm on 655, 750, 755, 7554
1750 rpm on 850/855. If speed does
drop, move throttle lever to maintain
the proper rpm.

3. Repeat Steps 1 and 2 to get right and left transmis-

sion forward and reverse.

4. Determine differential control pressures.

a. Left Forward . . . . . . . . . . . . . . . . . P5 minus P6
b. Right Forward . . . . . . . . . . . . . . . . P7 minus P8
c. Left Reverse . . . . . . . . . . . . . . . . . P6 minus P5
d. Right reverse . . . . . . . . . . . . . . . . . P8 minus P7

5. Below are guidelines for interpreting control pres-

sure differential:

850, 855
O-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Good
16-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Marginal
Over20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Bad

655. 750, 755, 755A

O-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Good
15-l 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Marginal
Over19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..bad

T60:'?026 412 1912:

Litho in U.S.A. (Feb-84) 9026-73 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:9PZb
P73100184
 Hydrostatic Sys tern

PROCEDURE g--CHARGE PRESSURE

AND VACUUM

This procedure is used to obtain neutral charge

pressure; operating charge pressure and charge pump
inlet vacuum.

The transmission oil pressure gauge on the dash

monitors the lowest charge pressure of the two
transmissions. If this gauge indicates abnormal read-
ing, pressures must be checked individually to deter-
mine which transmission has abnormal charge
pressure.

NEUTRAL CHARGE TEST

If charge pressure is abnormal in neutral only, the

neutral charge relief may not be functioning properly.
Test by running unit fast idle with FNR in neutral
monitoring neutral charge pressure (A).

If pressure is not to Spec, adjust by shimming neutral

charge relief valve (Spec 260-340 psi) (1723-2275
kPa) (17-23 bar).

NOTE It may be necessary to move FNR lever

forward and reverse within the neutral band to
detect the neutral pressure spike which is
approximately 75 psi higher than operating
charge pressure. A-Neutral Charge Port
B-Neutral Charge Relief Valve

655, 750, 755, 755A

A-Neutral Charge Port

B-Neutral Charge Relief Valve

9AQ;T95887 T95890 Tb0;9026 413 191283

Litho in U.S.A. (Feb-84) 9026-74 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T7W026P74100184
 Hydrostatic Sys tern

OPERATING CHARGE TEST

If charge pressure is abnormal in forward and reverse

only, the operating charge relief valve may not be
functioning properly. Test by running engine at fast idle.
Ease FNR into forward until tracks just start to creep
monitoring operating charge pressure on high pressure
manifold.

If pressure is not to Spec, adjust by shimming charge

relief valve Spec 180-240 psi.

If charge pressure is low and fluctuating both in neutral

and in forward and reverse, the oil to the charge may A-Operating Charge Test Port
B-Operating Charge Relief Valve
be restricted. This can be detected by a higher than
normal vacuum measured at charge pump. (See
655, 750, 755, 755A
Photo.)

A-Operating Charge Test Port

B-Operating Charge Relief Valve

850, 855

To read vacuum, run unit fast idle in neutral with oil at

operating temperature. Vacuum should not exceed 10
in. Hg (mercury) (5 psi). If high, filters, suction line, or
tubes in reservoir are restricted.

A-Charge Pump Vacuum Port Test

655, 750, 755, 755A

9AQ;T95883, T95898, T95888 T60;9026 414 191283

Litho in U.S.A. (Feb-84) 9026-75 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
176:9026
P75100184
 t Hydrostatic Sys tern

A-Charge Pump Vacuum Teet Port

9AQ;T95'391 T60;9026 462 191283

bitho in U.S.A. (Feb-64) 9026-76 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76:90*6
P76100184
 Hydras ta tic Sys tern

PROCEDURE lo-COOLING CIRCUIT

TEST (CASE PRESSURE)

In this test, transmission case pressure is monitored

to determine if the cooler bypass valve is functioning
properly and to determine if the cooler circuit has
excessive restriction.

For this test the temperature sending unit is installed

at the cooler bypass valve on the line that goes from
the transmission to the oil cooler bypass valve.

Begin this test with a cold unit.

While monitoring case pressure on either the right or

left transmission, start unit and heat oil per Procedure
2.

As the oil heats up, there will be a noticeable pressure

increase of approximately 10 psi when the thermostatic A-Case Pressure Test Port

bypass valve shifts and oil must be forced through the

655, 750, 755, 755A
cooler. This should occur approzimately 140-l 60°F.
If bypass valve does not shift by 18O”F, the valve spool
is stuck; the thermostatic pill is defective, or the valve
has been assembled incorrectly. (See Group 0360.)

Normal case pressures are listed below:

Cold oil bypass valve Open 5-l 5 psi 100”

Hot oil bypass valve Closed 25-50 psi 160”

Excessive high case pressure indicates restriction in

cooling circuit. Check lines, cooler or bypass valve.

A-Case Pressure Test Port

850, 855

9AQ:T95885, T95897 T60;9026 415 191283

Litho in U.S.A. (Feb-84) 9026-77 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T7W026P77100184
 Hydras tatic Sys tern

PROCEDURE 1 l--HIGH PRESSURE RE-

LIEF VALVE TEST

On units where tracks stall easily under load, the high

pressure relief valves may not be functioning properly.
To test, forward and reverse system, pressures are
monitored while the tracks are being stalled with the
track restraint bars.

A-Forward System Pressure

B-Reverse System Pressure
C-Forward Relief Valve
D-Reverse Relief Valve

655, 750. 755. 755A

A-Forward System Pressure

S-Reverse System Pressure
C-Forward Relief Valve
D-Reverse Relief Valve

850, 855

1. Install track restraint bars, cap the brake lines and

heat oil to operating temperature. (See Procedure 2)

2. Monitor forward and reverse system pressures with

10,000 psi gauge.

3. Operate engine at fast idle and ease the FNR lever

into forward. When system pressure no longer in-
creases as FNR lever is moved further, the high
pressure relief valve has opened.

9ART95884, T95899 T60;9026 416 191283

bitho in U.S.A. (Feb-84) 9026-78 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:90*6
P781001*4
 Hydrostatic System

NOTE: Carefully monitor transmission temperature

during this test. Temperature will rise very
quickly when operating in this ‘over relief”
condition. DO NOT exceed 160%

4. Check right and left relief pressures in forward and

reverse. Pressures should be between 6100-6500 psi
(4205944817 kPa) (420488 bar) for 655. 750,
755Aand6300--6700psi(43344--46096kPa)(434-
461 bar) for 850 and 855.

5. Adjust by adding or deducting shims.

NOTE: .OlO in. shim thickness equals approximately

300 psi,

A-Shim High Pressure Relief Valve

9AQ;T87715T60;9026417 191283

Litho in U.S.A. (Feb-84) 9026-79 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
TX;9026
P79mom4
 Hydrostatic Sys tern

PROCEDURE 124SOLATE TRANSMIS-

SION CHARGE PRESSURE LOSS

To proceed with this test, charge pressure loss must 2. Isolate the brake and bypass valve circuits by
be catagorized into one of the following: disconnecting and capping brake valve pressure line
on top of brake valve (See #3, Fig. 1)
a. Low charge in Neutral only or in Neutral and in
range. Run engine at idle unit in Neutral. If charge pressure
is normal, the charge loss is in brake or bypass circuit,
b. Low charge in range only-no load. go to Step 3. If charge pressure is still low, go to Step
a.
c. Low charge under load only.
3. Knowing the charge loss is in either the brake or
A-LOW CHARGE PRESSURE IN NEU- bypass circuit, further diagnosis amounts to eliminating
TRAL AND IN RANGE (No Load) components of these circuits. The easiest to check is
the brake piston seals. Since leakage past these seals
1. Always eliminate the easiest items first. Check the goes into the final drive inner housing , it’s oil level is
neutral charge relief valve for broken springs and a good indicator of seal leakage.
improper assembly. (See Procedure 9.)

l-Charge Pressure Oil 4=-Bypass Valve Pressure 6-Transmission Charge g-Bypass Valve Crossover
2-Reservoir Oil Line Pressure Gauge On Dash Pressure Line
3-Brake Valve Pressure Line 5-Brake Valve T-Right Bypass Valve W-Parking Brake Pressure Line
&Left Bypass Valve
Fig. l-Charge Pressure Circuit

9AQT60262 T60:9026 416 191263

Litho in U.S.A. (Feb-84) 9026-80 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76;9026
Pm100184
 Hydrostatic System

4. Reconnect brake valve pressure line to brake valve.

Remove inner final drive oil level check plugs (both
sides). If oil level is above plug, allow it to drain to the
proper level. Run engine at idle in neutral for approxi-
mately 1 minute. If there is no noticable increase in final
drive oil level, brake piston seals are not leaking
enough to cause low charge pressure.

5. The next step is to separate the bypass valves from

brake valve. Disconnect and cap the bypass valve
pressure line. (See Procedure 4, Fig. 1)

6. Run engine again at idle in neutral. If charge

pressure is now in the green zone, the leak is in one 3. Check motor servo o-rings if low charge pressure
or both bypass valves. is related to motor phase. If low charge pressure is in
motor phase only, check o-rings on motor servo can
7. The two bypass valves can also be isolated from nearest the front of machine.
each other. Disconnect and cap the bypass valve
crossover pressure hose at the left hand bypass valve. 4. Check pump servo can o-rings if low charge pres-
This is the fitting nearest the center of bypass valve sure is related to direction. If low charge pressure is
(See #9-Fig. 1.) in forward only, check forward servo can o-rings. If low
in reverse, check reverse servo can o-rings.
8. Run engine at idle in neutral. If charge pressure is
now in green zone, the leak is in left hand bypass valve. 5. Check for pump valve and bearing plate separation.
Remove and repair. If charge pressure is still low, leak
is in right hand bypass valve. Remove and repair. If leak a. With warm oil, run unit approximately Y2 speed
is not in brake or bypass valve circuits, monitor or fast idle-no load-decelerating. If charge pres-
neutral charge pressure on both transmissions to sure drops rapidly to 75-l 00 psi, the valve and
determine which transmission has the loss of charge. bearing plate in one of the transmission pumps
Check the following on bad transmission: may be running in a separate condition.

a. Motor low speed servo o-ring leaking internally. b. To isolate separation to one side, press steering
Remove and check. (Low speed motor servo is pedals or pull levers individually while unit is in
the servo nearest the rear of crawler.) the low charge condition. Whichever pedal that
is pressed causes charge pressure to increase
b. Charge pump may not be pumping or may have controls the transmission that has plate
suction restriction. Check charge inlet vacuum separation.
(See Procedure 9) Remove charge pump and
check. c. Pump plate separation can be caused by the
following:
c. Internal leakage from failed rotating group.
-0verspeed of transmissions
B-LOW CHARGE PRESSURE IN RANGE Check RPM
ONLY-No Load -Weak or failed transmission rotating
group block spring
1. Monitor individual transmission charge pressure to Replace spring
determine which transmission has malfunction (See
Procedure 9.)

2. The most common cause for a NO-LOAD in range

loss of charge is a failed operating charge relief valve.
Remove and inspect. (See Procedure 9.)

9AQ;T87703 T60;9026 419 191283

Litho in U.S.A. (Feb-84) 9026-81 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T7W026
P81100184
 Hydras ta tic Sys tern

C-CHARGE LOSS UNDER LOAD ONLY

This condition is usually caused by:

Operation with transmission oil temperature too high.

Varify transmission oil temperature. If consistantly
operating over 2OO”F, the cause is transmission oil
overheating. (See Overheating Diagnostic Flow
Chart)

Inefficient transmission:

If high oil temperature is not the cause of low charge

pressure the cause is an inefficient transmission.
Prior to removing transmission, check:

-High Pressure Manifold Parts

-Bypass Valve
-Transmission Fluid
-Drive Shafts
-Engine Clutch

Remove transmission and disassemble using the

Parts Evaluation Manual as a guide line for repair.

T60;9026 419A 19128

Litho in U.S.A. (Feb-84) 9026-82 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
17WO26PBZ
loo184
 Hydrostatic System

I
PROCEDURE 13-PUMP DISPLACEMENT
CONTROL VALVE NEUTRAL
ADJUSTMENT

This adjustment is used to match the neutral band in

each transmission with the neutral position on the FNR
lever on the transmission control valve.

This adjustment is also used to match the neutral band

in the transmissions with each other so both tracks start
at the same time when moving FNR lever out of neutral.

This adjustment is also used to adjust the tracking of

the crawler at speeds less than 2.5 mph. This is called
pump phase tracking

The purpose of this procedure is to obtain an initial

setting for the pump displacement control valve neutral
adjustment. Final adjusting will occur when pump
phase tracking is adjusted (See Procedure 15)

1. It is recommended that the unit be blocked off the

shop floor so tracks can turn freely.

2. Disconnect the linkage (A) from the FNR lever on

the transmission control valve and position lever in the
detented neutral position.

3. Remove the access plugs on both pump displace-

ment control valves. With the engine running at
approximately 3/4 throttle and the FNR lever on control
valve in neutral detent the adjustment can be made.

9AQT87725, T88311 T60;9026 420 210983

Litho in U.S.A. (Feb-84) 9026-83 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:9026
P83100184
 Hydrostatic System

4. To adjust, turn the l/8” recessed head allen screw

that is center of the slotted retainer.

A
CAUTION: Tracks will move during this
adjustment. Make sure tracks are free to
turn.

To determine neutral band, turn the adjusting screw

one direction slowly until track starts to creep. Then
turn in the opposite direction, counting number of turns,
until track creeps in opposite direction. Set the screw
in the center of that neutral band. Do the same for the
other track.

5. To check the adjustment, connect the linkage to the

FNR lever on control valve. Operate unit at idle cycling
the FNR lever full forward to full reverse rapidly several
times to insure that the springs within the displacement
control valve have seated themselves.

6. Move FNR lever very slowly out of neutral. Both

tracks should start at the same time. On the 655, 750,
755, 755A turn the adjusting screw “IN” to start track
sooner in FORWARD. On the 850 & 855 turn the
adjusting screw “OUT” to start track sooner in
FORWARD.

NOTE Finaladjustmentofpumpdisplacementcontrol
valves is usually required during the TRACK-
ING adjustments (See Procedure 15).

9AQ;T876%3 T60;9026 421 191283

Litho in U.S.A. (Feb-84) 9026-84 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
TX3026Pm100184
 Hydrostatic Sys tern

PROCEDURE 14-ISOLATE TRANSMIS-

SION CONTROL PRESSURE LOSS

This procedure is used to determine if there is a control

circuit leak in the transmission control valve, pump
displacement control valves, or motor displacement
control valves

A control pressure leak will usually be indicated by a

unit that has a mistracking complaint.

For this test transmission oil should be at operating

temperature 135-l 60” (See Procedure 2.)

Instrument to record P5, P6, P7, P8 differential control

pressures. (See Procedure 1.)

Disconnect both steering lever linkages at the steering

levers on the transmission control valve. Make sure
levers are fully to the rear against their stop screws.
This is to make sure that linkages are not holding
steering valves in a partial steer position that would
show up as a control oil leak.

2. Disconnect the Return to Neutral linkage from the

trip lever in left-hand console.

3. Disconnect the automatic control valve variable

orifice linkage (C) from the lever on the transmission
control valve (B) and rotate lever fully forward against
stop.

4. With the brake pedal locked down, run unit fast idle
with the FNR lever fully forward. Record P5, P6, P7,
P8 control pressures. The P5 differential control pres-
sure (P5 minus P6) and the P7 differential control
pressure (P7 minus P8) should not be more than 2 psi
apart. If they are, before attempting to isolate a loss,
varify that steering valve stop screws are adjusted
proper. (See Procedure 29.)

After completing the steering stop adjustment; if the

differential control pressures are more than 2 psi apart,
there is a leak in the control circuit on the low pressure
side.

9AQ;T87698, T87738, TB.3352 T60:9026 422 191283

Litho in U.S.A. (Feb-84) 9026-85 SP-579; TM-1 136, 1164, 1165, 1231, 1250
T76;9026
P85100184
 Hydrostatic Sys tern

5. Control circuit leakage could be in the following b. To isolate between the pump displacement control
areas: valve and motor displacement control valve, reconnect
lines to transmission control valve that were removed
a. External leakage from lines going to displace- in Step A and disconnect and cap lines from pump
ment control valves. displacement control valve to motor displacement
control valve and repeat the differential control pres-
b. Internal leakage at the bleed screw on the motor sure test in Step 4. If pressures are still more than 2
displacement control valve due to a loose screw or psi (.14 bar) apart, the leakage is in the pump
damaged seat. displacement valve circuit. (See Possible Cause in Step
5.) If pressures are within spec, the leak is in the motor
c. A damaged gasket between the transmission displacement control valve. Check items in Step 5.
control valve housing and port plate.

d. Leakage in the steering valve spool and sleeve

in the transmission control valve.

e. Leakage in the pump displacement control

valve gasket, side plate gasket, shuttle valve spool,
or control valve spool sleeve area.

f. Leakage in motor displacement control valve,

gasket, side plate gasket, or spool and sleeve area.

6. To isolate the leakage to the transmission control

valve; the pump displacement control valve or motor
displacement control valve, proceed as follows:

a. Isolate the transmission control valve from the

rest of the control circuit by disconnecting the lines
from the transmission control valve that go to the pump
displacement control valve on the side that had the low
control pressure. (Example-If the right hand control
pressure was low, disconnect lines 2 and 3, Fig. 1. If
left hand control pressure was low, disconnect lines 4
and 5, Fig. 1) Cap off both the fittings on valve and the
lines.

Then repeat the differential control pressure test in

Step 4.

If P5 and P7 differential control pressure is still more

than 2 psi (0.14 bar) apart, the leakage is in the
transmission control valve. Check areas in Step 5
G--D)-

If the control pressures are less than 2 psi (.14 bar)

apart, the leakage is in either the pump or motor
displacement control valve l-Transmission B-Pump Displacement
Control Valve Control Valve
2-Control Line A 7-Control Drain Line
3-Control Line 6 8-Control Pressure Line
4-Control Line C g-Motor Displacement Con
5-Control Line D trol Valve

Fig. l-Transmission Control Circuit (750, 755A, 655)

9AQ;T58446 T60;9026 423 191283

Litho in U.S.A. (Feb-84) 9026-86 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76;9cm
PB6
1001*4
 Hydrostatic Sys tern

PROCEDURE 15A-TRACKING TEST

PROCEDURE 15B-TRACKING
ADJUSTMENT

15A Track Tests:

On any mistrack complaint, two basic questions must

be answered prior to making any adjustments. They
are:
1. At what FNR lever position does mistrack
occur?

2. What is the mistrack pattern?

To answer these questions, the unit must be driven in

a level open area approximately 100 feet long.

1. PUMP PHASE TEST. With the engine at high idle,

run the crawler at approximately l/3 speed, (approxi-
mately 40 psi control pressure). Run in forward and
reverse For approximately 100 feet on level surface.
Record the tracking pattern. Refer to tracking chart
next to “Pump Phase”.

2. MOTOR PHASE TEST:

Run the unit at approximately 2/3 speed. (60-l 10 psi

control) in forward and reverse. Record the tracking
pattern. Refer to the tracking chart next to “Motor
Phase”

3. FULL SPEED TEST

Run unit at full speed. (122-l 26 psi Control Pressure

on 655,750,755,755A, and 132-l 36 psi on 850 and
855)ln forward and reverse. Record the tracking pat-
tern. Refer to tracking chart next to “Full Speed Only”

If the unit cannot be run outside, the sprocket speeds

and control pressure listed below can be used as a
guideline when making tracking related adjustments.
Final tracking adjustments must be made with the unit
outside on a level surface.

T60;9026 424 19121

Litho in U.S.A. (Feb-84) 9026-67 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T7L:90*6
P87100184
 Hydrostatic Sys tern

Differential Typical Sprocket Engine RPM

Control Pressure Speed

655, 750, 755, 755A

40 psi (3 bar) 22 rpm 2100
80 psi (6 bar) 44 rpm 2100
110 psi (8 bar) 61 rpm 2100

850/855
40 18 rpm 1800
80 36 rpm 1800
110 50 rpm 1800

Mistracking Patterns

“C” pattern means the crawler mistracks in the same

la
F
direction (right or left) in forward and reverse. (A) N
R

“S” pattern means the crawler mistracks in one

direction (right or left) in forward and the opposite
direction in reverse. (B)

“J” pattern means the crawler goes straight in one

direction (forward or reverse) but mistracks right or left
in the opposite direction. (C)

9AQ;T87935 Tb0:9026 425 191283

Litho in U.S.A. (Feb-84) 9026-88 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76;90*6
P88100184
 Hydrostatic Sys tern

TRACKING CHART

Speed or Phase Mistrack Pattern Adjustment Required for Correction

at Which Mis-
track Occurs

Pump phase Pump displacement control valve

F OI
(less than tracking adjustment
l/3 speed) N

R J 1

Servo gain adjustment on motor

F’ or servo can
N
R
$ t

A combination of two adjustments

1. pump displacement control valve
tracking adjustment
2. servo gain adjustment

Motor phase Motor displacement control valve

F adjustment
(more than Z/3 or
speed but less N
than full speed
R ? f

Rfi)t
F A combination of two adjustments
Of
1. motor displacement control valve
N 2. pump swashplate stop adjustment

Pump swashplate stops or a re-

F 01 stricted servo or swashplate
N
R f t

Full speed only Transmission motor high speed servo

F or
stop
N
R
j i

All speeds Check track tension (slow side may

F or be too tight)
N Control pressure loss problem
R (see procedure 14)
) t

9AQ:T95900 T60:9026 463 1912,

Litho in U.S.A. (Feb-84) 9026-89 SP579; TM-1136,1137,1164,1165,1231,1250

TX:9026
P89100184
 Hydrostatic Sys tern

PROCEDURE 16-ADJUST TRANSMIS-

SION CONTROL VALVE AFTER REPAIR
OR REPLACEMENT

Use Procedure 16 as a guide to the order of adjust-

ments after major repair or replacement of transmis-
sion control valve. All the following procedures can be
found in this group.

1. Bleed the transmissions. (See Procedure 3.)

2. Check the engine speed adjustment. (See Proce-

dure 6.)

3. Check the overpressure relief valve (Pl) setting.

(See Procedure 17.)

4. Check the pressure regulating valve (P2) setting.

(See Procedure 18.)

5. If the variable orifice was removed, do the variable

orifice installation adjustment. (See Procedure 19.)

6. Adjust the variable orifice stops. (See Procedure

20.)

7. Check the FNR speed control linkage adjustment.

(See Procedure 31.)

8. If the speed control valve (P3) was removed or

repaired, adjust the speed control screw. (See Proce-
dure 21.)

9. Adjust the FNR speed control lever stops. (See

Procedure 22.)

10. Adjust the automatic control valve (P4) setting.

(See Procedure 23.)

11. If the steering valves were removed or repaired,

adjust the steering valve stops. (See Procedure 26.)

12. Check the steering linkage adjustment. (See Pro-

cedure 28.)

13. Check the counter-rotation stop adjustment. (See

Procedure 29.)

14. Check the engine speed and transmission control

valve synchronization. (See Procedure 27.)

15. Perform the pump phase, motor phase and full

speed tracking check. (See Crawler Systems Checkout
Procedure in Group 9005.)

T60;9026 429 22098

Litho in U.S.A. (Feb-84) 9026-90 SP579; TM-l 136, 1137, 1164, 1165, 1231, 1250
576;9026
P90100184
 Hydrostatic Sys tern

PROCEDURE 17-TRANSMISSION CON-

TROL VALVE Pl RELIEF VALVE
ADJUSTMENT

The Pl Relief Valve protects the Control Pump when

the variable orifice is closed off while the engine is
running at fast idle.

1. To test, monitor Pl pressure at port marked “1” (A)

on top of Transmission Control Valve.

2. Disconnect variable orifice linkage (B) and rotate

lever (C) forward. (See Procedure 1.)

3. Pull the automatic control valve shut-Off handle up.

A-P1 Test Port

B--Variable Orifice Lever
C-Variable Orifice Linkage

4. Run unit fast idle in Neutral. Slowly rotate variable

orifice to the rear stop. The pressure reading should
be 280-340 psi (1931-2344 kPa) (19-23 bar) with
transmission at operating temperature of 135-l 60°F.
The valve (A) is shim adjusted. Add or remove as
required.

9AQ;T95892, T95896 T60;9026 430 191283

Litho in U.S.A. (Feb-84) 9026-91 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
Tm9026P91100184
 h’ydrostatic Sys tern

PROCEDURE 18-TRANSMISSION CON-

TROL VALVE PRESSURE REGULATING
VALVE P2 ADJUSTMENT

The P2 regulating valve maintains a constant pressure

P2 oil which is the baseline to which the automatic
control valve compares Pl pressure to prevent exces-
sive engine lugging when a load is applied.

1. To test, monitor P2 pressure at port marked “2” (A)

on top of transmission control valve.

2. Disconnect the variable orifice linkage (B) and rotate

the lever (C) forward against stop.

3. Pull the Automatic Control Valve shut-off handle up.

4. Run unit fast idle in Neutral. The P2 pressure should A-P2 Pressure Port
B-Variable Orifice Linkage
be 160-200 psi (1103-1379 kPa) (1 l-14 bar) with oil at
C-Variable Orifice Lever
operating temperature of 135”-160°F. D-P2 Pressure Regulating Valve

5. Adjust the valve by installing or removing shims.

9AQ;T95893 T60:9026 431 191283

Litho in U.S.A. (Feb-84) 9026-92 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:9026
P92100184
 Hydras ta tic Sys tern

PROCEDURE 19-VARIABLE ORIFICE

INSTALLATION

This Procedure is used to center the variable orifice

lever travel when the variable orifice cartridge is
installed in the Transmission Control Valve.

1. Before installing the cartridge, rotate the valve (A)

until the length (E) of the slot (C) is .40 (10 mm).

2. Install the variable orifice cartridge into the transmis-

sion control valve with the actuating lever a straight up
vertical position and tighten the two retainer cap
screws.

3. Whenever the variable orifice cartridge has been

removed from the valve, the variable orifice stops must
be readjusted. (See Procedure 20.) A-Variable Orifice Valve
E-Variable Orifice Valve Housing
C-Variable Orifice Valve Slot
D-Variable Orifice Housing Window
E-.40 in. (10 mm)

9AQ;T88323 T60:9026 432 220983

Litho in U.S.A. (Feb-84) 9026-93 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
176:90x
P93100184
 Hydrostatic Sys tern

PROCEDURE PO-VARIABLE ORIFICE

PRESSURE ADJUSTMENT

This procedure is used to set the transmission control

valve variable orifice lever stop screws (A).

IMPORTANT: Stop screws must be adjusted prop-

erly for the automatic control fea-
ture of the machine to fuction at all
engine speeds.

For this procedure, heat the transmission oil to 135-

160°F (60-71 “C). (See Procedure 2.) Monitor the
following:
Engine rpm
Pl-P2 Pressure Differential

A. Set the high rpm Variable Orifice Stop by doing the l-Variable Orifice Lever
2-High Variable Orifice Stop Screw
following:
~-LOW Variable Orifice Stop Screw
+Transmission Control Valve
4. Disconnect the linkage (5) from the variable 5-Variable Orifice Linkage
orifice lever (1) and rotate lever fully forward
against its stop. NOTE: Anytime either the high or low variable orifice
stop screws are adjusted, also check and
2. Run the unit at 2100 rpm (655, 750, 755, 755A) adjust the engine speed to transmission con-
or 1800 rpm (850, 855) and hold the variable trol valve synchronization. (See Procedure 27.)
orifice lever forward against its stop. The Pl, P2
pressure differential should be 50 c 1 psi (345
& 7 kPa) (3 & .07 bar).

3. Adjust the variable orifice high stop screw (2) to

obtain this pressure. Turn screw to IN to in-
crease pressure and to OUT to decrease pres-
sure. One-forth turn equals approximately 1 psi.

B. Set the low rpm variable orifice stop by doing the

following:

1. With the linkage (5) disconnected, rotate lever

(1) to the rear against its stop.

2. Run the unit at 1000 -c 5 rpm and hold the

variable-orifice to the rear against its stop. The
Pl, P2 differential pressure should be 60 psi t
1 (414 & 7 kPa (4 6 .07 bar).

3. Adjust the variable orifice low stop screw (3) to

obtain this pressure. Turn screw IN to increase
the pressure differential and OUT to decrease
pressure. One-forth turn equals approximately
1 psi differential pressure.

9AQ;T95886 T60;9026 433 191283

Litho in U.S.A. (Feb-84) 9026-94 SP579; TM-l 136, 1137, 1164, 1165, 1231, 1250
TX;9026
P941001ed
 Hydrostatic Sys tern

PROCEDURE 21-FNR LEVER NEUTRAL

BAND ADJUSTMENT (P3 Pressure
Adjustment)

Operational Check:
The FNR lever neutral band is the distance the FNR
lever must travel between the point at which the tracks
start to move in forward and the point at which the
tracks start to move in reverse. This distance (A) should
be .875 in.-1.5 in. measured at the console with
transmission oil at operating temperature.

If this neutral band is too narrow (less than .75 in.) the
operator may have difficulty in consistantly placing the
FNR lever in neutral. If the neutral band is too wide
(more than 1.5 in.) the unit may not reach full speed.

To adjust, turn the speed control valve adjusting screw

on front of the transmission control valve until the
neutral band is within the specified range. (See Photo.)
Turn the screw in to increase neutral band and out to
decrease neutral band.

If the neutral band is not centered on the console, see

Procedure 13-Pump Displacement Control Valve
Neutral Adjustment and Procedure 31-FNR Speed
Control Linkage Neutral Adjustment.

Alternate procedure using pressure gauges.

To set P3 differential control pressure on a new or

repaired valve, perform the following steps.
6 Slowly reduce engine speed until P4 differential
1. Instrument to monitor P3, P4, and P6 control control pressure is zero. Record P3 differential control
pressures per procedure 1 and heat transmission oil pressure.
to 135”--160°F (57”-71 “C) per procedure 2.
7. Repeat Steps 5 and 6 with FNR against the valve
2. Disconnect the return-to-neutral cable in the left stop in reverse.
console, the variable orifice linkage at the valve lever,
and the FNR linkage at the valve lever. 8. P3 differential control pressure should be 6 -c 1 psi
(41 + 7 kPa) for the higher pressure (forward or
3. With the FNR Lever in its neutral detent position, reverse). To increase pressure, turn the speed control
adjust both FNR lever stop screws so they just contact valve against screw out.
the lever.
9. Set transmission full speed control pressure per
4. Back out the FNR stop screws 2-l/2 turns, tighten Procedure 22.
the stop screw nuts, and reconnect the FNR link to the
FNR lever.

5. With the park brake pedal down the engine speed

at W.O.T., and the variable orifice lever in the full
forward positioln, move the FNR lever full forward until
it contacts the stop screw on the valve.

9AQ;T88312, T87724 T60;9026 434 201283

Litho in U.S.A. (Feb-84) 9026-95 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76;9026
P95100184
 Hydrostatic Sys tern

PROCEDURE 22-TRANSMISSION CON-

TROLPRESSUREFULLSPEED
ADJUSTMENT

This adjustment will insure that the crawler will achieve

full operating speed of 6.5 mph in forward and reverse.

The following are required to make this adjustment:

- Heat transmission oil to 135-l 60°F (57671 “C).
(See Procedure 2.)
-Monitor P5, P6, P7, and P8 differential control
pressure. (See Procedure 1.)

1. Disconnect the return to neutral cable from the trip

lever in left-hand console. This will allow the full speed
adjustment to be made without the track turning. Also
make sure the FNR lever on valve contacts the stop
screws before the FNR lever in the console hits the
stop screws.

2. Make sure the steering valve levers are fully rear-

ward against the steering lever stops. This may require
removing the steering linkage from the actuating levers
and holding levers rearward.

3. Pull the automatic control valve shut-off handle up

and run the engine at fast idle. Push down brake pedal.

4. Put the FNR lever in the full forward position and

record P5, P6, P7, and P8 differential control pressure.
Repeat with the FNR lever in full reverse position. The
differential pressures should be 124 + 2 psi (855 +
14 kPa) 655,750, 755,755A and 134 f 2 psi (924 +
14 kPa) (9 + .l bar) on 850 and 855.

5. If adjustment is required, turn the stop screws “A”

for forward and “B” for reverse. Turn screw out to
increase presssure and in to decrease pressure. If
turning the screw out does not increase pressure, the
FNR speed control handle neutral band is too wide and
must be adjusted. (See Procedure 21.)

IMPORTANT: Do not apply excessive force to the

FNR speed control handle because
the FNR lever stops on the valve can
be damaged.

6. To set the FNR lever stops in the console, move the

lever until stop screw on the valve is just being
contacted. Then adjust the lever stop screw in the
console (A) approximately .060 in. from the lever.
Repeat the reverse to set the FNR lever reverse stop
screw (B).

9AQ;T87738, T88335, T88336 T60;9026 435 201283

bitho in U.S.A. (Feb-84) 9026-96 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
Tm9026P96100184
 Hydrostatic System

PROCEDURE 23-AUTOMATIC
CONTROL VALVE ADJUSTMENT (P4
PRESSURE) (ENGINE PULL DOWN)

This adjustment determines how far the automatic

control valve will let the engine RPM drop during heavily
loaded conditions. When the engine is lugged down to
this RPM, the automatic control valve will reduce the
track speed to maintain this engine speed.

Prior to making this adjustment, make sure the follow-

ing are correct:

-Engine High and Low Idle (See Procedure 6-

Engine Speed Adjustment)
-Variable Orifice Stop Screws (See Procedure
20-Engine Speed Adjustment)
-Varialble orifice to Injection Pump Phasing (See
Procedure 27 Injection Pump and Transmission
Control Valve Synchronization)

1. To check this adjustment, both the engine and

transmissions must be heated to operating tempera-
ture 135-160°F (57-70°C) either by operating the
unit or by installing the track restraint bars. (See
Procedure 2-Transmission Warm-up.)

2. Run unit at fast idle and put a heavy load on the unit.
This load can be some type of operation, such as,
counter-rotate tracks holding hydraulics over relief. If
in an area where the unit cannot be driven, the track
restraint bars may be used.

3. Slowly move the FNR lever to full speed either

forward or reverse. Record the rpm to which the engine
pulls down to in this condition.

4. This pull down rpm can be adjusted to suit the needs

of the customer. For most applications the following
speeds will give a good combination of track speed and
speed of hydraulic functions:

655, 750, 755, 755A . . . . , , . . . . . . . . . 1800-1850

850, 855 . . . . . . . . . . . . . . . . . . . . . . . . . 1550-1600

If a customer desires more speed for hydraulic func-

tions, set the pull down rpm higher by turning screw (A)
in. If a cutomer desires less track slow down when
using a hydraulic function, set the pull down rpm lower
by turning screw (A) out. However, care should be
taken as to not lag the engine excessively.

9AQ:T88339 T60;9026 436 201283

Litho in U.S.A. (Feb-84) 9026-97 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76;9026
P97100184
 Hydrostatic Sys tern

5. The automatic control valve can be adjusted

without loading the transmissions. Monitor pressures
P4 and P6 ono auto control valve.

6. Heat the transmission to 135”-180°F.

7. Disconnect the return to neutral cable from the trip

lever in the left hand console.

8. Disconnect the automatic control valve orifice

linkage from the valve lever on the transmission control
valve and rotate the lever fully forward against the stop.

9. Lock down the emergency brake pedal and start

the engine.

IO. Set the engine speed to fast idle and slowly move
the FNR speed control lever into full forward.

11. With the variable orifice lever fully forward against

the stop, slowly reduce the line engine speed to:

1875 + 10 rpm . . ~. . . . . . ,600 and 700 Series

1650 f 10 rpm . . . . . . . . . . . . . . . . . .800 Series

Set the P4-P6

Differential pressure . . . . . . . . . . ~. .80 -C 10 psi

T60;9026 464 22128

Litho in U.S.A. (Feb-84) 9026-98 SP-579;TM-1136,1137,1164,1165,1231,1250

T7W026P98100184
 Hydrostatic Sys tern

PROCEDURE 24-AUTOMATIC CON-

TROL VALVE OPERATIONAL CHECK

This procedure is used to determine if the automatic

control valve spool in the transmission control valve is
functioning properly at all engine speeds.

Prior to making this check, make sure the following are

correct:

-Engine high and low idle (See Procedure 6-

Engine speed adjustment)
-Variable orifice stop screws. (See Procedure
20-Variable Orifice Pressure Adjustment.)
-Variable Orifice to Injection Pump Phasing (See
procedure 27-Injection Pump and Transmis-
sion Control Valve Synchronization)

For this check, the unit must be operated outside with

a 100 ft (30.5 m) area to drive the unit.

1. Heat the transmission oil until the transmission

temperature guage on the dash reads in the middle of
the green area. This can be done by operating the unit
or by installing the track restraint bars (See Procedure
2-Transmission Warm-Up.)

2. Run unit at fast idle with the hydraulics system

building relief pressure-(Bottom a function.)

3. Move the FNR lever to full forward. While running

in this loaded condition, slowly and evenly move engine
throttie rearward to reduce engine speed to the l/2
throttle position. The automatic control valve will
maintain approximately the same rate of pull down for
any engine speed above the Y2 throttle position. If the
unit cycles at any engine speed during this test, the
automatic control valve spool may be dragging in the
cartridge or the small spring may be pushing unevely
on the front end of the spool. (See Section 0360 in
appropriate technical manual.)

4. Repeat Step 3 starting with the engine throttle at l/2

speed and slowly and evenly move throttle lever
forward until full engine speed is reached.

NOTE: It may be normal for a small amount of engine

cycling to occur if engine throttle is moved
below fi speed for this test.

T60:9026 437 2012

Litho in U.S.A. (Feb-84) 9026-99 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
176:9026
P99lOOlL
 Hydras ta tic System

PROCEDURE 250AUTOMATIC CON-

TROLVALVEACCUMULATORCHECK

The Automatic Control Valve accumulator dampens 6. Very rapidly move the FNR lever into full speed
any rapid change in control pressure. This type of forward monitoring P9 pressure rise time. The P9, P6
pressure change would occur if the transmission FNR differential pressure should rise to 100 psi in not less
lever were moved very rapidly especially through a than 2.5 seconds or not more than 3.5 seconds.
directional change. If machine response to rapid FNR
lever movements seem very aggressive, the P9 accu- a. If the P9 pressure rise time is less than 2.5
mulator piston may be stuck or the orifices may be seconds, the accumulator piston is stuck, the
plugged. spring has failed, or the accumulator orifices are
too large. (See Group 0360.)
A very quick operational check for a stuck P9 spool is
to simulate a stuck piston and operate the unit. b. If the P9 pressure rise time is more than 3.5
seconds, the accumulator piston is sticking, the
1. Connect a short jumper hose between P4 and P9 orifice screen is plugged, or the orifices are
test parts on the transmission control valve and plugged.
operate the unit.

2. Make sure all air is bled from the jumper hose.

If operating the unit in this manner does not change

the aggressiveness of the unit, the P9 accummulator
piston is stuck or the P9 orifices are plugged.

For a more thorough check of the P9 accumulator

circuit use the following procedure:

1. Monitor P4, P6, P9 Control Pressures on the

transmission control valve (See Procedure 1.)

2. Disconnect the return to neutral cable from trip lever

in left-hand console.

3. Disconnect the linkage from the variable orifice

lever on the transmission control lever and hold lever
forward against the stop screw.

4. Make sure the steering valve levers are fully to the

rear against their stops.

5. With the emergency brake pedal locked down and

the automatic control valve shut-off handle pulled up,
run unit at fast idle in neutral.

9AQ;T87738, T95894 T60:9026 438 201283 (

Litho in U.S.A. (Feb-84) 9026-l 00 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76;YOYb
P100
100184
 Hydrostatic Sys tern

PROCEDURE 26-STEERING VALVE

STOP ADJUSTMENT

This adjustment will insure that the steering valve

spools return to a “no steer” position when steering
levers or pedals are released. The no steer position of
the spools is determined by adjustable stop screws on
the front of the tranmission control valve.

If the stop screw is adjusted too far in, the steering

spool will not return far enough which will cause a loss
of control oil pressure that results in mistrack
complaint.
If the stop screw is adjusted too far out, the steering
spool will return to far and operator will have to pull the
lever or depress the pedal an excessive amount before
the track begins to slow down to steer the machine.

To adjust these steering stop screws, the transmission

oil should be approximately room temperature.

1. Monitor P5 pressure for the left side and P7 pressure

for the right side. (See Procedure 1.)

2. Disconnect the return-to-neutral cable from the trip

lever in the left hand console.

3. Disconnect linkage from steering lever (A).

4. With the emergency brake pedal locked down, run

unit at fast idle and move FNR lever into full speed
forward.

5. Holding lever (A) rearward against the stop turn the

stop screw out until maximum pressure (P5 left and P7
right) is obtained. Now turn the screw in until P5 or P7
pressure drops 1 to 2 psi. Then trun the screw back
out approximately l/2 turn. This will allow for approxi-
mately .040 in. (1 .O mm) free movement of the steering
valve lever before control pressure starts to drop.

9AQ;T87738; T88317 T60;9026 439 201283

Litho in U.S.A. (Feb-84) 9026-101 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T7wm26
PlOl100184
 Hydrostatic Sys tern

PROCEDURE 27-INJECTION PUMP AND This adjustment makes the automatic control feature
TRANSMISSION CONTROL VALVE of the crawler function at all engine throttle setting.
SYNCHRONIZATION
Prior to checking this adjustment make sure the
In this procedure the linkage that connect the fuel following are correct:
injection pump to the variable orifice on the transmis-
sion control valve is checked and adjusted. 1. Engine fast and slow idle (See Procedure 6.)

IMPORTANT: The fuel injection pump fast and 2. Variable orifice pressure adjustments (See Proce-
slow idle stop screws must be con- dure 20.)
tacted at the same time as the high
and low variable orifice stop screws This entire procedure is done with the engine off.
are contacted on the transmission
control valve. A-Throttle lever to variable orifice stops adjustment.

T45952N

Flg. l-Transmission Control Linkage

l-Throttle Lever 5-Pivot Casting ‘I--Cross Shaft Lever 1 l-Injection Pump Cable
2-FNR Lever Lower Level E-Cross Shaft Lever Quick Disconnect
3-Neutral Lock Lever S-Link from Plvot g-Variable Orifice Lever ll-dable To Fuel
4-Control Link To Cross Shaft lO-Cross Shaft Lever Injection Pump

9AQ;T45952 T60;9026 440 230983

1

Litho in U.S.A. (Feb-84) 9026-l 02 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76;902t.
P102100184
 Hydrostatic System

1. Place throttle lever (1) parallel to the FNR lever (2)

locked in neutral.

2. Adjust control link (4) so the pivot casting lower lever

(5) is in the vertical straight down position.

3. Adjust link (6) so the cross shaft lever (7) is in a

vertical straight up position. The other cross shaft lever
(8) should also be in the vertical straight up position.

4. Reposition the throttle lever so the front edge of the

lever is about 1.25 in (31.6 mm) from the front end of
the slot in the console. Adjust the stop screw (A) so
it contacts throttle (B).

5. Adjust the ball socket end of variable orifice lever

linkage so that the ball socket just slips over the ball
on lever (A) when contacting the high variable orifice
stop screw (B).

6. Pull throttle lever back until the variable orifice lever

(A) contacts the low variable orifice lever stop screw
(W.

9AQ;T88351, T88413, T88353 T60;9026 441 230983

Litho in U.S.A. (Feb-84) 9026-103 SP579; TM-1136, 1137, 1164, 1165, 1231, 1250
Tm9026
Pm31001*4
 Hydras tatic Systern

7. Adjust:

A-The slow idle stop screw (A) under the console

so it just contacts the throttle lever (B).

B-Throttle lever to injection pump cable adjustment.

1. Adjust the injection pump cable quick disconnect

ball joint (11) Fig. 1 so there is .625 in. (15.9
mm) of threads showing between the two
locking nuts (B & D). Adjust the injection pump
cable to injecion pump lever quick disconnect
ball (4-Fig. 2) the same way.
2. Loosen cable support clamp (3) and cable
end (6) so both can be slid up and down.
3. With the throttle againt the fast idle stop in
console, slide cable 1 in the injection pump lever
(5) and in the support bracket (2) so the cable
makes a 90” angle with the injection pump lever
(5) when the levers are contacting the fast idle
stop on the injection pump. Tighten (3) and (6).
4. With the throttle lever against the low idle
stop in the console, make sure the injection
pump lever (5) is just contacting the low idle stop
on the injection pump. If it is, this adjusment is
finished. If it is not contacting the stop, continue
to Step 5.
5. Loosen cable end (6) and slide up or
down in injection pump lever so the low
idle stop is just contacted on injection
pump. Tighten (6).
6. Recheck the fast idle setting. If not correct,
loosen cable clamp (3) and slide cable in bracket
(2) until idle stops match.

C-Screw in the throttle lever stops in the console two

turns to provide some over travel at the low and high
idle positions.

D-Continued on next page

Fig. 2-Fuel Injection Pump

14able !&-Injection Pump Lever

2-Bupport Bracket 6-Gable End
“able Clamp ‘I-Injection Pump
4-Ball Joint

9AQ;T88354, T88355, T45953 T60;9026 442 230983

Litho in U.S.A. (Feb-84) 9026-104 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T76:902b
P104
100184
 Hydrostatic Sys tern

D-Drive Check

As a final check or quick check for proper synchro-

nization the following check is recommended:

NOTE This check requires about 100 ft of fairly flat

surface to drive the unit.

1. With transmission and engine at operating

temperature, run unit at l/4 throttle position.

2. Bottom a hydraulic function (blade tilt on dozers

and any function on loaders). Place FNR lever
in 3/4 to full speed position.

3. Slowly and steadily increase engine speed at a

rate in which the unit will travel about 100 ft when
full RPM is reached. The unit should not stop or
slow down excessively at any point in this RPM
range.

4. Repeat Step 3 starting with engine at fast idle

and hydraulics over relief. Slowly and steadily
decrease RPM to about Va throttle.

5. If a “Dead Spot” occurs, the unit is not properly

synchronized and procedure No. 27 must be
repeated.

It is normal for tracks to stop during this drive check

if engine RPM is set below the l/4 throttle setting.

T60;9026 443 23091

Litho in U.S.A. (Feb-84) 9026-l 05 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:9026
P105
100184
 Hydrostatic Sys tern

PROCEDURE 28-STEERING LINKAGE

ADJUSTMENT

In this procedure the steering linkage is adjusted so that

when the steering lever or pedal is in the “No-Steering”
position, the steering levers on the transmission control
valve are fully to the rear against their stops. The
linkage is also adjusted so that when the steering
pedals or levers are in the maximum counter-rotate
position, the levers on the valve are also in the full
counter-rotate position.

Prior to making this adjustment, make sure the steering

valve stops on the transmission control valve are
adjusted properly (See Procedure 26.)

This adjustment is made with the engine not running.

1. Disconnect right and left control rods (3 or 4, Fig.

1) from right and left steering valve levers (1 and 2).

2. Adjust right control rod (4) so that the stud on the l-Left Steerlng Valve !i-Bell Crank Support
Lever Bracket
ball joint slips freely into the steering valve lever (2).
P-Right Steering Valve GRight Bell Crank
Lever Support Casting
3. Push right pedal (or pull right lever) completely into 3-Left Control Rod 7-Left Bell Crank
the counter-rotation position and hold in that position. 4-Right Control Rod Support Casting
Push right steering valve lever (2) forward and see if
the stud on the ball joint slips freely into the right Fig. 1 - Steering Linkage
steering valve lever.
8. Check for the potential over-center condition be-
4. If not, move the bellcrank support casting (6) up or tween the bell crank arm and ball joint on both sides
down l/8 inch (3 mm) and tighten cap screws. of the linkage in the following manner:

5. Readjust right control rod (4) per Step 3. A-Depress the right or left pedal (or pull lever) to the
full travel position.
Again check to see if stud goes freely into steering
valve lever with pedal (or lever) in the counter-rotation B-Before releasing the pedal (or lever) hold the right
position. or left steering valve lever (1 or 2), then release the
pedal (or lever).
Repeat adjustment as necessary until correct amount
of travel is obtained. C-If the pedal (or lever) returns to its fully released
position while holding the steering valve lever, the bell
NOTE: Should a situation arise where the bell crank crank arm and ball joint have gone over the center and
casting has used up all its travel in the slot and the linkage must be readjusted per Steps 1 thru 7 until
more travel is needed in the direction, the bell the potential over-center position is eliminated.
crank support bracket (5) may be moved.
Repeat Steps 3 thru 7 if this adjustment is 9. Tighten all hardware.
made.

7. Repeat Steps 3-6 for adjustment of left steering

linkage (1, 3 and 7)

9AQ;T60276 T60;9026 444 201283

Litho in U.S.A. (Feb-84) 9026-106 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
TX,;9026
Plc’b100184
 Hydrostatic System

I
PROCEDURE 290STEERING COUNTER
ROTATION STOP ADJUSTMENT

This adjustment will insure that the track comes to a

complete stop when the steering pedal (or lever) is
pushed (or pulled) to the position where the increased
effort is felt. This is just before the track starts to
counter rotate.

This adjustment requires the machine to either be

driven outside or be blocked up off the floor or ground
so the tracks are free to turn.

1. Operate the unit at about l/3 speed forward and

engine speed about l/2 throttle.

2. Push the steering pedals (or pull levers) one at a

time to the position where the increased effort is
detected.

If the respective track does not stop, the Counter

Rotate Stop Collar must be adjusted.

3. Remove the set screws in Stop Collar (A). Turn Stop

Collar (A) counterclockwise if track continued to creep
forward in Step 2 and clockwise if track continued to
creep in counter rotate (Reverse).

4. Put a small drop of Loctitee on each set screw and

reinstall when adjustment is complete.

9AQ;T88422 T60;9026 445 201283

L
Litho in U.S.A. (Feb-64) 9026,107 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
776:9026
P107
100184
 Hydrostatic Sys tern

PROCEDURE 30 RETURN TO NEUTRAL

LINKAGE ADJUSTMENT

This adjustment will insure that the FNR lever will return
to true Neutral when the emergency brake pedal is
depressed and the FNR lever is either in forward or
reverse.

This adjustment is made with the engine not running.

Move the FNR lever to the full forward position.

Depress the emergency brake pedal firmly. Do the
same in reverse. The FNR lever must return to the
center of the neutral slot in the “Z” pattern in the
console.

1. Disconnect the return to neutral cable (A) from the

trip lever (B).

2. Lock the FNR lever on the console in neutral and

depress and lock the emergency brake pedal.

3. Rotate the trip lever (8) downward so the bar

contacts both pins in the neutral return cam assembly.

4. Pull the cable (A) tight in the console and adjust the
yoke (A) so the hole in the yoke lines up with the hole
in the trip lever. Shorten the yoke 2 more turns. Tighten
the nut.

5. Slowly release the emergency brake pedal until the

holes in the yoke and trip lever are in line. Insert and
tighten cap screw.

Recheck the operation and if the FNR lever still does

not return to the center of the neutral position in the
console, further adjustment is required.

6.Lock the emergency brake pedal down. Loosen cap

screw (A) holding the return cam assembly to the pivot
shaft.

7. Loosen the cap screws holding the control head

assembly and move the control head until the FNR
control lever is in the center of the neutral slot.

8. Tighten the control head cap screws and the cam

assembly to pivot shaft cap screw (A)

9AQ;T88428, 188425, T88426 T60;9026 446 260983

Litho in U.S.A. (Feb-84) 9026-l 08 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T7W026
PI081001*4
 Hydrostatic Sys tern

1
PROCEDURE 31-FNR SPEED CONTROL
LEVER LINKAGE NEUTRAL
ADJUSTMENT
3. Adjust the FNR lever verticle link (3) in the console
This adjustment will insure that the FNR Speed Control so the lower pivot lever (5) is in the vertical straight
Lever is in the neutral slot in the console the same time down position.
the lever on the transmission control valve is in its
neutral position. 4. Adjust the linkage rod between pivot lever (5) cross
shaft pivot lever (6) so that pivot lever (6) is in the
This adjustment is done with the engine not running. straight up vertical position.

1. Lock the FNR lever (1) in neutral and disconnect the 5. Adjust the linkage rod between the center cross
linkage from the lever (9) on the transmission control shaft pivot (7) and lever (9) on the transmission control
valve. valve so that the holes in the linkage rod and lever (9)
are exactly in line. Install linkage cap screw.
2. Rotate the lever (9) on the Transmission Control
Valve forward and reverse to find the neutral detent
position.

I-FNR Lever S-Vertical Link !bLower Pivot Lever 7-Center Cross Shaft Pivot Lever
P-Neutral Lock Lever 4-Upper Pivot Lever S-Cross Shaft Pivot Lever S-Cross Shaft
9-FNR Speed Control Lever
9AQ;T45951 Tb0;9026 447 211283

Litho in U.S.A. (Feb-84) 9026-l 09 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T7W026
P109
100184
 Hydrostatic Sys tern

Control Lever Drag Adjustment

The amount of force required to move the throttle lever

and the transmission FNR lever is adjustable to suit the
operator.

1. Loosen the six set screws (A). Three are on the

engine throttle control head facing out and three are
on the FNR control head facing towards the center of
the machine.

2. Using a spring scale (8) on the throttle control head

IN until the force required to move the throttle lever is
19 & 2 Ibs. (85 & 9N)

3. Check the FNR lever the same way. The force

required to move the FNR lever should be about 6 Ibs
(27 N)

9AQ;T88477 T60;9026 448 260983

1
Litho in U.S.A. (Feb-84) 9026-l 10 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:9026
PllO100184
 Hydrostatic Sys tern

PROCEDURE 32-BRAKE VALVE CABLE

ADJUSTMENT

This adjustment will insure that the brake valve plunger

is depressed the proper amount when the emergency
brake pedal is depressed against the pedal stop.

1. Depress and lock the brake pedal in the down

position. The brake plunger (6) should be bottomed in
its bore. To check, disconnect ball joint (2) and try to
move lever (1) forward. if the lever (1) can be moved
forward, the plunger is not bottomed.

2. Adjust ball joint (2) so lever (1) is all the way forward
and plunger is bottomed when the brake pedal is
locked down.

3. When brake pedal is released there must be some

gap (amount is not critical) between the lever (1) and
the plunger (2). If not readjust.

A
CAUTION: The tracks may turn during the
following check. Make sure the general
area is clear.

4. To check the operation, run the unit at low idle and

depress and lock the brake pedal. Slowly move the
FNR lever into full speed forward or reverse. If the
tracks turn or engine stalls, the brake valve linkage is
not adjusted properly or the brake valve is faulty.

9AQ:T60269 T60;9026 449 260983

Litho in U.S.A. (Feb-84) 9026-l 11 SP-579; TM-1 136, 1137, 1164, 1165~~1231, 1250
~76:9026
Pill 100184
 Hydrostatic Sys tern

PROCEDURE 33-AUTOMATIC CON-

TROL VALVE SHUT-OFF CABLE
ADJUSTMENT

This adjustment will insure that when the transmission

automatic control valve shut-off T-handle is pushed
down, the transmission automatic control valve
functions.

This adjustment is made with the engine not running.

1. Lock the automatic control valve shut-off T-handle

in the DOWN position. The cable should be slightly
forcing the spool (C) .into its bore.

2. If not, disconnect the cable clevis (A) from lever (D).

3. Push and hold shut-off valve spool (C) in the bottom

of its bore.

4. Unlock the T-handle, loosen lock nut (B), and adjust

clevis (A) so the cable is slightly preloaded when the
T-handle is locked down and the spool is bottomed in
its bore.

9AQ;T88482 T60;9026 450 201283 )

 Hydraulic Sys tern

Litho in U.S.A. (Feb-84) 9026-113 SP-579; TM-1 136, 1137, 1164, 1165, 1231, 1250
T7W026
PI13100184
 Hydrostatic System/Circuit Diagrams

l-Trapped Oil 22-Automatic Control Valve Shutoff Valve 42-From R.H. Transmission Drain Port
2-Reservoir Oil 23-P3 Speed Control Valve 43-From R.H. Transmission Charge Purr
“Suction Oil 24-Pl Overpressure Relief Valve 44-L-H. Transmission Pump
4-P4 Control Oil 25-P2 Pressure Regulating Valve 45-Transmission Operating Pressure Valv
S-P3 Control Oil 26-Right Steering Lever 46-L.H. Transmission Bypass Valve
6-P2 Control Oil 27-Variable Orifice 47-To R.H. Transmission Bypass Valve “BP
7-Pi Control Oil PI-Variable Orifice Lever Port
&Charge Oil 29-Right Steering Valve 48-From R.H. Transmission Bypass Valv
8-System Pressure Oil 38-Hydrostatic Reservoir “7 Port
16-Parking Brake 31-Transmission Filters 49-L.H. Transmission Charge Pump
1 l-L.H. Transmission Motor 32-05 Cooler 58-L.H. Transmission End Cap
1 P-Motor Displacement Control Valve 33-05 Cooler Bypass Valve 51-Forward High Pressure Relief Valve
13-Transmission Control Pump 34-Transmission Temperature Gauge 52-L.H. Transmission Manifold Valv
14-Neutral Charge Relief Valve BE-Transmission Pressure Gauge Assembly
15-Pump Displacement Control Valve 36-To R.H. Transmission Charge Pump 53-Shuttle Valve
16-Transmission Control Valve 37-Brake Valve 54-Operating Charge Relief Valve
17-Left Steering Valve 38-To Brake Pedal linkage 55-Reverse High Pressure Relief Valve
16-FNR Speed Control Lever 38-To R.H. Parking Brake 56-Low Speed Servo Cylinder
W-Left Steering Lever 40-From R.H. Transmission Pump Displace- 57-Cheek Valve
PO-FNR Valve ment Control Valve “H” Port B&Forward Servo Cylinder
PI-Automatic Control Valve 41-To R.H. Transmission Pump Displace-
ment Control Valve “X” Port

Legend for Transmission Hydrostatic Circuits for Left Transmission in Forward Operation

l-itho in U.S.A. (Feb-84) 9026-114 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T700Zb
Pi14100184
 Hydrostatic System

l-Charge Oil 13-Automatic Control Valve Shut-Off 23-Motor Displacement Control Valve
2-Pl Control Oil Valve (Normal Operation) (Motor Phase - Motor Swashplate Min-
3-P2 Control Oil 14-Rate Control Orifice imum Angle)
4-P3 Control Oil l!k-Speed Control Valve (Full Forward) 24-Reservoir
6-P4 Control Oil 16-Right Steering Valve 26-Control Pump
6-P9 Control Oil (Forward - No Steering) PI--Motor Displacement Control Valve
‘I-Reservoir Oil 17-P2 Pressure Regulating Valve (Neutral Phase-Motor Swashplate
8-Suction Oil 18-Pl Overpressure Relief Valve Maximum Angle)
9-Equalized Pressure Oil W-Orifice 27-Pump Displacement Control Valve
W-Left Steering Valve (Forward - PO-Variable Orifice (Neutral Phase - Pump Swashplate
Full Steering) 21-Shuttle Valve (Forward) Neutral Position)
ll-FNR Valve (Full Forward) 22-Pump Displacement Control Valve
12-Automatic Control Valve (Motor Phase - Pump Swashplate Max-
(Normal Operation) imum Forward Angle)

Legend for Transmission Control Circuit

Litho in U.S.A. (Feb-84) 9026-117 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:9026
P117100184
 Hydrostatic Sys tern

l-Charge Oil 17-011 Cooler 34-Charae Relief Valve

2-Pl Control Oil 18-Oil Cooler Bypass Valve 35-Maniiold Shuttle Valve
3-P2 Control Oil 19-Transmission Temperature Gauge 38-Forward High Pressure Relief
4-P3 Control Oil 29-Automatic Control Valve Valve
8-P4 Control Oil Shutoff Valve 37-Neutral Charge Relief Valve
8-Trapped Oil 21-Automatic Control Valve 38-Charge Pump
7-Suction Oil 22-FNR Valve 39-Brake Valve
8--Reservoir Oil 23-Automatic Control Valve 49-Safety Check Valve
9-L.H. Charge Pump P9 Accumulator 41-Transmission Operating Pressure
Suction Filters Ill-Left Steering Valve Valve
19-Hydrostatic Reservoir 25-Right Steering Valve 42-Transmission Operating Pressure
1 l-R.H. Charge Pump 28-Transmission Pump Gauge
Suction Filters 27-R.H. Transmission 43-Manual Brake Release Pump
12-Pl Overpressure Relief Valve 28-Pump Displacement Control Valve Valve
13-Transmission Control Valve 29-Shuttle Valve 44-Parking Brake
14-Automatic Control Valve 39-Transmission Bypass Valve 4%Brake Poppet Valve
Variable Orifice 31-Reverse High Pressure Relief Valve 48-Brake Shuttle Valve
15-P2 Pressure Regulating Valve 32-Motor Displacement Control Valve 47zTransmission Control Pump
18-P3 Speed Control Valve 33-Transmission Motor 48-L.H. Transmission

Legend for Hydrostatic Schematic (Neutral)

Litho in U.S.A. (Feb-84) 9026-118 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
T76:9026
PliS100184
 Hydrostatic System/Glossary of Terms

GLOSSARY OF TERMS

ACV . . . . . . . . . . . . . . . . . . . . . . . . . . Automatic Control Valve

“C” Mistrack Pattern . . . . . . . . . . . . Machine tracking in the form of a “C”. The machine mistracks in the same
direction in forward or reverse.

Fast Side . . . . . . . . . . . . . . . . . . . . . . The track on this side of the machine starts to move before the other track.

FNR . . . . . . . . . . . . . . . . . . . . . . . . . Forward Neutral Reverse

FNR Speed Control Handle . . . . . . A handle on the operator’s left-hand console that selects the machine
direction and speed.

FNR Speed Control Lever . . . . . . . A lever located on the left side of the transmission control valve that moves
the FNR speed control valve. The lever is operated by the FNR speed
control handle.

Index or Indexing . . . . . . . . . . . . . . . One track starts to move before the other when the FNR speed control
handle is moved out of neutral position.

“J” Mistrack Pattern . . . D. . . . . . . . Machine tracking in the form of a “J”. The machine mistracks in one
direction only.

MDCV _. . . . . . . . . . . . . . . . . _. . . . . . Motor displacement control valve.

Motor Phase . . . . . . . . . . . . . . . . . . . The speed of machine above 2.8 mph (4.5 km/h) where the motor
swashplate moves from 18 to 7”.

PDCV . . . . . . . . . . . . . . . . . . . . . . . . . Pump displacement control valve.

Phasing Point . . . . . . . . . . . . . . . . . The condition when the pump is at its maximum displacement and the motor
is at its maximum displacement.

Pull-down . . . . . . . . . . . . . . . . . . . . . . The point during machine operation when the automatic control valve
changes track speed to limit the decrease in engine rpm due to machine
load.

Pump Phase . . . . . . . . . . . . . . . . . . The speed of machine from 0 to 2.8 mph (0 to 4.5 km/h) where the pump
swashplate moves from 0 to 18”.

“S” Mistrack Pattern . . . . . . . . . . . . Machine tracking in the form of an I‘S”. The machine mistracks in opposite
directions in forward and reverse.

Slow Side . . . . . . . . . . . . . . . . . ~. . . The track on this side of the machine starts to move after the other track.

7” Servo Cylinder Stop . . . . . . . . . . A stop located in the rearward motor servo cylinder used to adjust a “C”
mistrack at full speed.

18” Pump Full Speed Stop . . . . . . . A stop located in the pump front cover used to reduce speed of fast track.

18” Servo Cylinder Stop

(Servo Gain) . . . _ . . . . . . . . . . . . . . A stop located in the forward motor servo cylinder used to adjust a “C”
mistrack in pump phase.
Tbw9026
100020283
Litho in U.S.A. (Feb-84) 9026-I 25 SP-579; TM-l 136, 1137, 1164, 1165, 1231, 1250
TW9026
Pi25100184
 Hydras ta tic Sys tern

Litho in U.S.A. (Feb-84) 9026-l 26 TM-1136, 1164, 1165, 1231, 1250

T76:9026
P126
mom4
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydrostatic System 9026- 127

Procedure 13 - Bleeding the Transmis-

sion Control Circuit
S.N. (296203- ) with cab
S.N. (283491- ) without cab

IMPORTANT: Check for air in the reservoir oil,

per visual inspection air check procedure.

A. Disconnect the return-to-neutral cable from the

trip lever in the left-hand console. Lock down the
emergency brake pedal.

B. Open the transmission control bleed screws

three turns. The bleed screws (Fig. 93) are located on
the transmission motor displacement control valves,
and are accessible through the access hole in the rear
Fig. 97-Transmission Control Bleed Screws
of the transverse case.
I. The following abbreviated bleed procedure may
NOTE: The bleeding will be internal and there will
be used if only the transmission oil filters or vacuum
be no loss of oil with the bleed screws open.
switches are removed or the oil was drained from the
reservoir:
C. With the emergency brake pedal locked down
and the automatic control valve shut-off handle (4, Fig.
NOTE: The transmission oil temperature must be at
94) pulled up, start the engine and heat the transmis-
least 66°F (19°C).
sion to 100°F (38°C) minimum.

D. P5 and P7 Bleed: Set the engine at low idle and

1) With the emergency brake pedal locked down
and the automatic control valve shut-off han-
move the transmission speed control lever (2, Fig. 94)
dle (4, Fig. 94) pulled up, start the engine. Do
slowly to the full forward position. Hold in this position
not move the transmission speed control
for one minute.
lever from the neutral position.

E. P5 and P7 Control Spool Bleed: With the trans-

2) With the engine set at low idle and the trans-
mission speed control lever in the full forward position,
mission speed control in neutral allow the unit
push both steering pedals to the dead track position for
to operate for two minutes. The bleed pro-
30 seconds.
cedure is complete.

F. P6 and P8 Bleed: With the engine at low idle

move the transmission speed control lever (2, Fig. 94)
slowly to the full reverse position. Hold in this position
for one minute.

G. P6 and P8 Control Spoof Bleed: With the trans-

mission speed control lever in the full reverse position,
push both steering pedals to the dead track position for
30 seconds.

H. Repeat paragraphs D, E, F and G.

This completes the bleed procedure.

Litho in U.S.A.
 90 System Testing JD750 Crawler Bulldozer
9026-128 Hydrostatic System TM- 1136 (Apr- 79)

Procedure 14 - Steering Valve Stop Ad- B. Start crawler and heat transmission fluid to
justment on the Trans- 140 - 160°F (60 - 71°C) per Procedure 5, this group.
mission Control Valve
C. Disconnect the return-to-neutral cable from the
NOTE: Use to set differential control pressures for trip lever in the left-hand console. Disconnect the
proper steering operation. steering linkage rods from both steering levers on the
transmission control valve.
A. instrument to record P5, P6, P7 and P8 control
pressure.
D. Lock down the emergency brake pedal and start
the engine. Set engine speed at W.O.T. (wide open
1)Remove P5, P6, P7, and P8 port plugs in
throttle) and move the forward and reverse speed
transmission control valve and install quick
control lever into full forward. With the automatic con-
connectors. Connect hoses from P5 connec-
trol valve variable orifice lever rotated fully forward
tor to No. 1 port (1, Fig. 94), from P6 con-
against the stop, record the P5 differential control
nector to No. 2 port (2) from P7 connector to
pressure (P5 pressure minus P6 pressure). This value
No. 5 port (5) and from P8 connector to No. 6
should be 124 ?Z 2 psi (9 ? 0.14 bar) (9 +- 0.14
port (6) in switching unit.
kg/cm2). If not correct, adjust per Procedure 12, this
group.
2) Connect hoses from gauge port A (7) to No. 3
‘I port (3) and from gauge port C (9) to No. 4
En port (4) in switching unit.
To record P5 control pressure using the switching
unit, set switch A (1, Fig. 95) in no. 1 position, switch B
(2) in no. 3 position, and switch C (3) in off position.
3) Connect hose from gauge port B (8) in
Then record P6 control pressure by moving switch A
switching unit to 0 - 300 psi (0 - 21 bar)
(1) to the no. 2 position.
(0 - 21 kg/cm*) gauge connector (10) in hy-
drostatic analyzer.

l-No. 1 Port ~-NO. 5 Port g-Gauge Port C

~-NO. 2 Port ~-NO. 6 Port lO-Gauge Connector
~-NO. 3 Port 7-Gauge Port A 11-O - 300 psi (0 - 21 bar)
~-NO. 4 Port &Gauge Port B (0 - 21 kg/cm*) Gauge

Fig. 94-Instrument to Record

P5, P6, P7 and P8 Control Pressure

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydrostatic System 9026-129

E. With the P5 differential control pressure set at To record P7 control pressure, set switch A (1, Fig.
the specified value, loosen steering stop screw lock nut 95) to off position, switch B (2) in no. 4 position, and
and turn the screw out far enough to be sure the P5 switch C (3) in no. 5 position. Then record P8 control
differential control pressure is maximum (if pressure pressure by moving switch C (3) to the no. 6 position.
remains constant as the screw is backed out, pressure
is maximum). Then turn the screw in until the P5
differential control pressure drops 1 to 2 psi (0.07 -
0.14 bar) (0.07 - 0.14 kg/cm2). Now turn the screw out
again until P5 differential control pressure returns to
maximum (approximately l/4 turn) and tighten the
screw lock nut.

F. Repeat the adjustment procedure on the other

side while recording the P7 differential control pressure
(P7 minus P8 pressure). l-Switching Valve A %-Switching Valve C
a-switching Valve B

Fig. 95-Hydrostatic Switching Unif

G. Reconnect steering linkage rods, automatic

control valve variable orifice lever linkage and return-
to-neutral cable.
q
’ 1

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9026-I 30 Hydraulic System TM- 1136 (Apr- 79)

Procedure 15 - Steering Linkage Adjust- C. Disconnect the return-to-neutral cable (1, Fig.
ment 97) in the left-hand console. Lock down the emergency
brake pedal.
NOTE: Use to adjust the right and left steering
linkage. CAUTION: For safety reasons, also block
a up the crawler so the tracks are off the
A. Instrument to record P5, P6, P7 and P8 control ground.
pressure.
D. Disconnect the steering valve control rods (5 and
1) Remove P5, P6, P7, and P8 port plugs in 6) from the levers (2 and 3) at the transmission control
transmission control valve and. install quick valve.
connectors. Connect hoses from P5 connec-
tor to No. 1 port (1, Fig. 96), from P6 con- E. Loosen the two bell crank support brackets (7) to
nector to No. 2 port (2), from P7 connector to crossmember (10) cap screws and adjust the bracket
No. 5 port (5) and from P8 connector to No. 6 so the cap screws are in the middle slot position.
port (6) in switching unit. Tighten the cap screws.

.a Connect hoses from gauge port A (7) to No. 3 F. Loosen the right bell crank support casting (8) to
port (3) and from gauge port C (9) to No. 4 bracket (7) cap screws and adjust bell crank support
port (4) in switching unit. casting so the cap screws are in the middle slot posi-
tion of the bracket. Tighten the cap screws.
3) Connect hose from gauge port B (8) in
switching unit to 0 - 300 psi (0 - 21 bar) (0 - 21 G. Adjust the right steering valve control rod (5) so
kg/cm*) gauge connector (10) in hydrostatic that the stud on the ball joint slips freely into the
analyzer. steering lever (3) hole on the transmission control
valve, with the steering lever held tight against the rear
B. Start crawler and heat transmission fluid to 140 _ stop. Connect the control rod to the valve lever.
160°F (60 - 71°C) per Procedure 5, this group.

l-No. 1 Port ~-NO. 5 Port g--Gauge Port C

~-NO. 2 Port ~-NO. 6 Port lo-Gauge Connector
3-40.3 Port 7-Gauge Port A 114 - 300 psi (0 - 21 bar)
~-NO. 4 Port &Gauge Port B (0 - 21 kg/cm*) Gauge

Fig. 964nstrument to Record

P5, P6, P7 and PE Control Pressure

Litho in U.S.A. -
JD750 Crawler Bulldozer System Testing
TM- 1136 (Apr- 79) Hydrostatic System 9026-1~~

63 n

T45972N

l-Return-to-Neutral Cable 4-Automatic Control Valve 7-Bell Crank Support Bracket

2-Left Steer Lever Variable Orifice Lever S-Right Bell Crank Support Casting
3-Right Steer Lever 5-Right Control Rod g-Left Bell Crank Support Casting
6-Left Control Rod 1 O-Crossmember

Fig. 97-Steering Linkage

H. Disconnect the automatic control valve variable To record P7 control pressure, set switch A (1, Fig.
orifice linkage (4, Fig. 97) from the valve lever on the 98) to off position, switch B (2) in no. 4 position, and
transmission control valve. Rotate the automatic con- switch C (3) in no. 5 position. Then record P8 control
trol valve lever fully forward against the stop. Pull out pressure by moving switch C (3) to the no. 6 position.
automatic control valve shut-off handle in left hand
console. Now push the right steering pedal (or pull lever) to its
full counter-rotation position and record the P7 dif-
I. With the emergency brake pedal locked down, ferential control pressure (P7 minus P8 pressure). This
start the engine and set engine speed to W.O.T. (wide
value should be the same as the P7 differential control
open throttle). Now slowly ease the forward and re-
pressure recorded before.
verse speed control lever to its full forward position.
Record the P7 differential control pressure (P7 minus
P8 pressure). This value should be 124 + 2 psi (9 +
0.1 bar) (9 + 0.1 kg/cm’). (If not correct, adjust per
Procedure 12, this group.)

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9026-132 Hydrostatic System TM- 1136 (Apr- 79)

J. If the second P7 differential control pressure is 4) Repeat steps G, H, I and J until both the P7
lower than the first P7 differential control pressure, differential control pressures read the same.
proceed as follows:
1) Return forward and reverse speed control K. Follow steps F, G, H, I and J to adjust the left
lever to neutral and shut down engine. steering linkage except record the P5 (P5 minus P6)
differential control pressures.
2) Loosen the right bell crank support casting to
bracket cap screws and move casting ap- To record P5 control pressure using the switching
proximately l/8 inch (3.18 mm) down in the unit, set switch A (1, Fig. 98) in no. 1 position, switch B
slots of the bracket and tighten the cap (2) in no. 3 position, and switch C (3) in off position.
screws. Then record P6 control pressure by moving switch A
(1) to the no. 2 position.
3) Repeat steps G, H, and 1.

,,,_- -

l-Switching Valve A 3-Switching Valve C

2-Switching Valve B

Fig. 984iydrostatic Switching Unit

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90 I
TM- 1136 (Apr- 79) Hydrostatic System 9026-133

Procedure 16 - Steering Neutral Stop Ad- 3) Connect hose from gauge port B (8) in
justment switching unit to 0 - 300 psi (0 - 21 bar) (0 - 21
kg/cm*) gauge connector (10 in hydrostatic
NOTE: Use to insure track stops when steering analyzer.
pedal (lever) picks up increased effort (second spring)
before counter-rotation. B. Start crawler and heat transmission fluid to 140 -
Procedure 16-A - Steering Neutral Stop 160°F (60 - 71°C) per Procedure 5, this group.
Adjustment (Recom-
mended Shop Proce- C. Disconnect the return-to-neutral cable (1, Fig.
dure) 100) in the left-hand console. Lock down the emer-
gency brake pedal.
A. Instrument to record P5, P7 and P8 control
pressure.

1) Remove P5, P6, P7, and P8 port plugs in

A CAUTION: For safety reasons, also block
up the tractor so the tracks are off the
ground.
transmission control valve and install quick
connectors. Connect hoses from P5 connec- D. Disconnect the automatic control valve variable

q
tor to No. 1 port (1, Fig. 99) from P6 con- orifice linkage (2) from the valve lever on the trans-
nector to No. 2 port (2) from P7 connector to mission control valve. Rotate the automatic control ’ ’
No. 5 port (5) and from P8 connector to No. 6 valve lever fully to the rear against the stop. Pull out
port (6) in switching unit. automatic control valve shut-off handle in left hand
console.
2. Connect hoses from gauge port A (7) to No. 3
port (3) and from gauge port C (9) to No. 4
port (4) in switching unit.

l-No. 1 Port ~-NO. 5 Port g-Gauge Port C

~-NO. 2 Port ~-NO. 6 Port lO-Gauge Connector
~-NO. 3 Port 7-Gauge Port A 11-O - 300 psi (0 - 21 bar)
b--No. 4 Port 6-Gauge Port 0 (0 - 21 kg/cmz) Gauge

Fig. 994nstrument to Record

f5, PS, P7 and PB Control Pressure

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9026-134 Hydrostatic System TM- 1136 (Apr- 79)

l-Return-to-Neutral Cable 3-Right Steering Neutral Stop 5-Sleeve (2 used)

2-Automatic Control Valve 4-Left Steering Neutral Stop g--Steering Support
Variable Orifice Lever

Fig. IOO-Steering Neutral Stop Adjustment

E. Loosen the set screws on the right neutral stop To record P7 control pressure, set switch A (1, Fig.
(3, Fig. 100). With the emergency brake pedal locked 101) to off position, switch B (2) in no. 4 position, and
down, start the engine and set engine speed at low switch C (3) on no. 5 position. Then record P8 control
idle. Move the forward and reverse speed control lever pressure by moving switch C (3) to the no. 6 position.
to the full forward position. Now push the right steering
pedal (or pull lever) while recording the P7 and P8
control pressures. Push the pedal (or pull lever out)
until the P7 and P8 control pressures read as close as
possible to the same value (less than 5 psi [0.34 bar1
[0.35 kg/cm21 difference between the two pressures).
With the pedal or lever held in this position, adjust the
neutral stop until it just comes in contact with the
sleeve (5) on the steering support (6). Tighten the set
screws on the neutral stop.

l-Switching Valve A 3-Switching Valve C

2-Switching Valve B

‘F;g. 70 l-Hydrostatic Switching Unit

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydrostatic System 9026-l 35

F. Repeat Step E for the left neutral stop (4, Fig. Procedure 16-B - Steering Neutral Stop
100) while recording the P5 and P6 pressures. Adjustment (Alterna-
tive Field Procedure)
To record P5 control pressure using the switching A. Check that the steering linkage is adjusted cor-
unit, set switch A (1, Fig. 101) in no. 1 position, switch rectly. See Procedure 15. Correct adjustment must be
B (2) in no. 3 position, and switch C (3) in off position. obtained before proceeding to Step B.
Then record P6 control pressure by moving switch A
(1) to the no. 2 position. B. Disengage the automatic control valve function
by pulling up on the automatic control valve shut-off
G. To check for correct adjustment of steering link- handle and locking in the up position.
age and neutral stops per Procedures 15 and 16, this
group: C. Block up the unit so the tracks are off the ground.

A
1) Place forward and reverse speed control CAUTION: Before moving the Forward and
lever in neutral and release emergency brake Reverse Speed Control Lever from neutral,
pedal.
make sure the surrounding track area is clear.

2) With the crawler blocked up so the tracks are D. Loosen or remove the set screws on the neutral
off the ground, start the engine and run at
stops (3 and 4, Fig. 100).
slow idle. Rotate the automatic control valve
lever fully to the rear against the stop.
E. With engine running at low idle, set a slow vehi-
cle speed with the Forward and Reverse Speed Con-
A CAUTION: Before moving the for-
ward and reverse speed control
trol Lever.

lever into forward, make sure the sur-

F. Slowly depress the right steering pedal (or pull
rounding track area is clear. the right steering lever) until the right track stops turn-
ing. Adjust the neutral stop (3) to contact the sleeve (5)
3) Slowly move the forward and reverse speed on the steering support (6) at this point. Tighten or
control lever into forward and run the tracks
reinstall set screw.
at approximately l/3 speed.
NOTE: The neutral stop can be rotated up to one-
4) With the tracks running at l/3 speed, push ha/f turn to improve access to the set screw without
the right steering pedal (or pull lever) to the
significantly affecting the neutral stop adjustment.
point where increased pedal effort is felt
(neutral stop contacting the sleeve). At this G. Repeat step F for the left neutral stop (4).
point the track should be stopped. Then push
the pedal way down (or pull the lever all the H. After adjustment is made, operate steering
way out). At this point the track should be pedals (or levers), with engine at slow idle and tracks
running in reverse. Repeat the same proce- running at l/3 speed, to insure for correct adjustment.
dure on the left steering pedal or lever.

NOTE: In the field the crawler does not

have to be blocked up to make this check.
The crawler may be driven on the ground in
an open area to check step (4).

H. Reconnect return-to-neutral cable and automat-

ic control valve variable orifice lever linkage. Push in
automatic control valve shut-M handle.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9026-l36 Hydrostatic System TM- 1136 (Apr- 79)

Procedure 17 - Return-to-Neutral Cable pushed completely down and locked; move control
Adjustment head assembly either forward or rearward to make
lever go into the neutral position as described in Step
A. Completely depress brake pedal to determine if A. Tighten cap screws to secure control head assem-
F-N-R lever returns to the neutral position. For lever to bly to console. Tighten cap screw on cam assembly to
be safely in neutral it must be free to slide sideways proper torque.
without hitting the corners of the 2 pattern in the
console.

B. Loosen cap screw holding cam adapter assem-

bly to pivot shaft in control head so that adapter is free
to rotate on shaft. Loosen cap screws holding control
head assembly to inner wall of left console so that
assembly is free to slide in slots. With brake pedal

l-Forward and Reverse 2-Neutral Lock Lever 4-Return Cam Assembly 6-Return-to-Neutral Cable
!Speed Control Lever 3-Control Head Bracket S-Trip Lever ‘I-Brake Pedal Arm

Fig. 102-Return-to-Neutral Adjustment

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydrostatic System 9026-137

Release brake pedal and check for return of F-N-R

lever to neutral by:

1) Place forward and reverse speed control lever

into full forward position. Depress the emergency
brake pedal all the way; the forward and reverse
speed control lever should return to neutral.

2) Place the forward and reverse speed control

lever into full reverse position. Depress the
emergency brake pedal all the way; the forward
and reverse speed control lever should return to
neutral.

C. If lever still does not properly return to the neutral

position the bulkhead fitting at console end of return to
neutral cable may be adjusted for a change in the
amount of cable travel. Also the balljoint on the end of
the cable may be adjusted for a change in the length of
cable assembly.

D. Repeat Step 6 if a change is made in Step C.

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90 System Testing JD750 Crawler Bulldozer
9026-138 Hydrostatic System TM- 1136 (Apr- 79)

Procedure 18 - Transmission Automatic B. Adjust cable yoke (4) such that the shut-off valve
Control Valve Shut-Off bottoms out just before the shut-off T-handle on the
Valve Cable Adjustment L.H. console with the valve in the “IN” position.

NOTE: Use to insure proper operation of the shutoff C. Install pin and cotter pin.
valve.

A. Remove pin and cotter pin from cable yoke (4,

Fig. 103).

T45975N

l-Valve Spool Yoke 3-Actuating Lever !i-Shut-Off Cable

Z-Pin 4-Cable Yoke GShut-Off Handle

fig. 103-Transmission Automatic Control Valve

ShuGOff Valve Cable Adjustment

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Hydrostatic System 9026-139

Procedure 19 - Engine Speed Adjust-

ment
NOTE: Use to set high and low idle for engine
operation.

A. Disengage engine cold weather disconnect

clutch.

B. Disconnect engine speed control cable quick

disconnect end (2, Fig. 106) from injection pump lever
(1).

C. Check injection pump throttle lever for proper

operation. Check to see that there is no debris between
the high and low idle stop screws and stops, and that
lever override works freely.

D. Warm engine up. Run engine and rotate injec-

tion pump throttle lever fully to the rear until it touches
the high idle stop (3). Record engine speed. It should
read 2300 to 2320 rpm. If not correct, adjust injection
l-Injection Pump Lever 4-Fuel Injection Pump
pump high idle stop screw to obtain specified speed. P-Speed Control Cable ~-LOW Idle Override Screw
3-High Idle Stop ~-LOW Idle Stop
E. Back out the low idle override screw (5) on the
injection pump lever far enough to make sure the low Fig. 106-Engine Speed Adjustment
idle stop screw (6) in the injection pump cover is being
contacted. IMPORTANT: Whenever either the high or low
idle speeds are adjusted on the injection pump, the
F. Engage engine cold weather disconnect clutch. engine speed control lever to injection pump cable
Rotate the injection pump lever fully forward until the adjustment has to be made. Refer to Engine Speed
low idle stop screw in the injection pump cover is and Transmission Control Valve Synchronization,
contacted. Record the engine speed. It should read Procedure 4, this group.
975 to 1025 rpm. If not correct, adjust low idle stop
screw (6) to obtain the specified speed.

G. With the injection pump lever held against the

low idle stop, adjust the low idle override screw (5) until
the engine speed just begins to raise above the low idle
speed set in Step F. Then back off screw l/2 turn and
tighten.

H. Reconnect the engine speed control cable (2).

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9026-l 40 Hydrostatic System TM- 1136 (Apr- 79)

Procedure 20 - Pump Displacement Con- point between forward and reverse. With the engine
trol Valve Neutral Adjust- running at slow idle, shift the forward and reverse
ment speed control lever between forward and reverse to
reseat the displacement control valve springs. Do the
NOTE: Use to set the neutral band for the trans-
above procedure for both transmissions.
mission pump swashplate. (Also see Procedure 3.)

D. To check for correct adjustments:

IMPORTANT: Insure neutral has been set for the
FNR speed control lever linkage and the P3 speed
control valve, per Procedures 3 and 10, prior to 1) With tracks on the ground and the engine
running at approximately 2100 rpm, move the
making this adjustment.
forward and reverse speed control lever
slowly into forward and observe that both
1. For safety reasons, block up the crawler so the
tracks start to move at the same time.
tracks are off the ground.

B. Remove the neutral adjustment plug (1, Fig. 105) 2) If one track starts to move before the other,
return the forward and reverse speed control
on the back (toward rear of tractor) of the pump dis-
lever into neutral and turn the adjusting screw
placement control valve (3). With the forward and
of the track that starts first slightly counter-
reverse speed control lever locked in its neutral posi-
clockwise. Repeat step (1). Do this until both
tion, start the engine and run at approximately 2100
tracks start to move at the same time.
rpm .

C. With an Allen wrench, turn the neutral adjusting 3) Reinstall the neutral adjustment plug in the
pump displacement control valve.
screw slowly clockwise to a point where the track just
starts to move forward. Then slowly turn the adjusting
screw counterclockwise, while counting the turns, until
the track just begins to move in reverse. Now turn the
adjusting screw half the amount of the turns counted in
the clockwise direction. This should now be the mid-

l-Neutral Adjustment Plug 2-Pump Displacement Control Valve

Fig. lO5-Pump Displacement Control Valve Neutral Adjustment

Litho in U.S.A.
JD750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Mar-78) Miscellaneous Components 9030-l

Group 9030 ~
MISCELLANEOUS COMPONENTS
DIAGNOSING MALFUNCTIONS
TRACKS 2. Drifting of crawler to right or left, resulting from
whichever is the tighter track.
Possible results of incorrect track adjustment are
listed below.
3. Fast wear on pins, bushings, and track links.

Loose Track 4. Fast wear on drive sprockets and idler wheels.

1. Very fast wear on pins, bushings, and track links. Too much wear on complete track system because
track cannot move as much as it should.
2. Unnecessary and fast wear on sides of drive
sprocket teeth and idler wheel flanges. 5. Unnecessary wear on final drive bearings and oil
seals.
3. Possible damage to, or breakage of, drive
sprocket, idler wheel and idler wheel bracket, fenders, Misaligned Track
side frames, and rollers.
1. Drifting of crawler from side to side.

4. Track may move out of the sprocket in both

2. Too much wear on idler wheel flanges and front
forward and backward operation. Track may be thrown
idler flanges.
off when crawler is turned.

3. Too much track link and drive sprocket wear.

5. Noisy track.
4. Operator constantly having to steer the crawler to
6. Track filling up with material.
keep it from drifting.

Tight Track
1. Not enough drawbar power and ground speed.
Crawler will not take rated working load.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9030-2 Miscellaneous Components TM- 1136 (Mar-84)

ADJUSTMENT

A
Track Tension CAUTION: There may be high pressure in the
track adjuster cylinder. Do not visually inspect
Track tension is determined by measuring amount of
the check valve. Always note track tension. If grease
sag in center of track between carrier roller and front
does not immediately flow out the vent hole, drive the
idler. Tension of each track is adjusted by a hydraulic
unit forward and backward slowly, then tighten
track adjuster.
check valve.

IMPORTANT: Never lubricate fitting on hydraulic

track adjusting cylinder unless track is in need of
adjustment.

When operating track in conditions where dirt is

pushed into the track system, check track tension as
much as necessary. Tension may increase when dirt is
pushed into the track. Check coils of recoil springs too.
Dirt in the recoil spring can cause slowdown of the idler
travel and recoil action. This slowdown can result in too
much load on the track link assemblies, recoil unit and
final drive components.

IMPORTANT: When forward edge of front idler is

l-Grease Fitting 3-Vent Hole approximately 1 inch (25 mm) from the end of the
2-Check Valve track frame, the track adjuster stop will contact the
track frame and no further increase in track tension
Fig. 1-Ad+ tingTrack Tension can be obtained. To avoid damage, recondition
Adjust sealed track chain tension so there is l-l -l/2 track.
in. (28-38 mm) sag. Adjust lubricated track chain ten-
sion so there is l-1/2-2 in. (38-51 mm) sag. When
measuring sag, a pin and bushing must be over the
center of the front carrier roller.

Adjust track tension by fastening a grease gun to the

grease fitting on the track adjuster. Use a grease gun
that has a maximum capacity of 8000 psi (552 bar) (562
kg/cm*).

IMPORTANT: Never, at any time, use a grease

gun having a capacity higher than 8000 psi (552 bar)
(562 kg/cm*) to adjust track. Break the line, fit in
connector, and put in a pressure gauge (0 to 10,000
psi [0 to 689 bar] [0 to 703 kg/cm*] capacity) in
grease gun tube to check pressure. If piston cannot
be moved with this type of grease gun, disassemble
track adjuster and release seized parts.

To tighten track, apply grease with gun to the correct

tension.

To loosen track, turn the check valve one to three

turns counterclockwise. This will allow grease to flow
out through the vent hole.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Miscellaneous Components 9030-3

Front Idler Guides Inner Guide Adjustment (Vertical)

The shims (2, Fig. 2) are designed to prevent Loosen cap screws on both the inner (4, Fig. 2) and
looseness caused by wear. If point of connection is outer guides (3). Pry up on the inner guide and mea-
loose, install shims as needed. sure the gap between the block (5) and the inner guide
(4). Add shims (2) to obtain 0.00 to 0.04 in. (0.0 to 1 .O
mm) gap.

Outer Guide Adjustment (Horizontal)

Center the idler between track frame (2, Fig. 3) so
dimension A and B are equal. Remove outer guides (1
and 5) if necessary. Adjust the right outer guide (1) with
shims (6) so the two dimensions “A” equal. Adjust the
left outer guide (5) with shims so the two dimensions
“B” equal.

Tighten the idler guide cap screws to 85 lb-ft (112

Nm) (12 kg-m).

l-Horizontal Adjusting Shims 3-Outer Guide

P-Vertical Adjusting Shims 4-Inner
6-Block

fig. P-front Idler Guide Components

l-Right Outer Guide 4-Left inner Guide

P-Track Frame 6-Left Outer Guide
3-Right Inner Guide B-Shim (as required)

Fig. 3-Front Idler Guide Shims

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9030-4 Miscellaneous Components TM- 1136 (Apr-79)

Carrier Roller Alignment To align front carrier roller, stretch a string between
the outside of the rear carrier roller flange and the side
of the front idler flange. Loosen front carrier roller-to-
front crossbar support cap screws and slide front car-
rier roller in or out so side of flange is aligned with string
(Fig. 4). Make sure centerline of roller is perpendicular (
to track chain and tighten cap screws.

Fig. 4-Front Carrier Roller

Carrier roller alignment is important in the reduction

of track wear.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Heating and Air Conditioning 9031-l

Group 9031
HEATING AND AIR CONDITIONING
HEATING SYSTEM
GENERAL INFORMATION When the valve is open, coolant returns to the water
pump by-pass pipe.
Coolant from the engine block or cylinder head is
moved by hoses and pipes to the heater core, and then
The blower draws air through the heater core and
to the heater valve. The purpose of the valve is to
directs it inside the body. On both air conditioned and
permit or restrict flow of coolant as desired by the
non-air conditioned bodies, the blower used for heating
operator.
is the same one used for pressurizing.

‘8
DIAGNOSIS AND TESTING

First Checks
When experiencing heating system problems, first
Diagnosing Malfunctions
Proceed with the following list of symptoms and
q
perform the following checks: causes when the first checks have been performed
and the system still does not operate correctly.
1. Check to see if the engine coolant is at the proper
level and warm enough to give the best heating results. Not Enough Heating

Defective engine thermostat

2. Make sure heater control is on. Heater hoses
Foreign material in heater core or hoses
leaving and entering the heater valve and heater core
Heater valve not working correctly
should be hot. If they are not, the heater control is not
Pressurizer blowers not working correctly
operating or not adjusted properly; there is a restriction
Obstruction in air inlet
in either the heater core or hoses or heater hoses are
kinked.
Heater Valve Not Shutting Off
Coolant Flow
3. Make sure heater shut-off cocks are open.
Inlet and outlet hoses reversed
4. Check system air filters for restrictions. Defective valve

5. Check for drafts around doors and panels. Heater valve control cable
not adjusted properly.
6. Check heater hoses for restrictions.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9031-2 Heating and Air Conditioning TM- 1136 (Apr- 79)

l-Evaporator 16Adapter, Water Pump

P-Expansion Valve 17-Special Connector, Engine Block
3-Thermostat Switch l&Heater Block to Cylinder Block Return
4-Evaporator to Coupling Low Pressure Hose
Refrigerant Line 19-Water Pump to Heater Block Supply Hose
E-Coupling to Evaporator High Pressure lo-Heater Block
Refrigerant Line 21-Heater Block Return Hose
8-High Pressure Coupling, Male and Female 22-Shut-Off Cock
~-LOW Pressure Coupling, Male and Female 23-Heater Block Supply Hose
8-Coupling to Compressor Low Pressure 24-Cab Floor Heater Block
Refrigerant Line 25-Cab Floor Heater Block to Heater Core
g--Receiver Dryer to Coupling High Supply Hose
Pressure Refrigerant Line 28-Heater Valve Control Cable
l&--Condenser to Receiver Dryer High 27-Heater Core
Pressure Refrigerant Line a&-Heater Core to Cab Floor Heater Block
11 -Receiver Dryer Return Hose
12-Compressor to Condenser High Pressure 29-Heater Valve
Refrigerant Line 38-90” Return Hose
13-Service Valve 31-Heater-Return Line
14-Compressor, 24-Volt 32-90” Supply Hose
15-Condenser 33-Heater Supply Line

Legend for Fig. I-Component Location - Heating and Air Conditioning System

l-Heater Inlet Hose 13-Schrader-Type Service Valves

2-Heater Outlet Hose U-Adapter, Engine Block
3-Evaporator l!%Condenser Fan Motors
4-Heater Core 18-Condenser
g--Expansion Valve 17-Receiver - Dryer Inlet Line
8-High Temperature Switch l&Condenser Outlet Line
~-LOW Pressure Refrigerant 19-Sight Glass
Line (Larger Line) PO-Receiver - Dryer
&Thermostat Sensing Tube 21-Evaporator Inlet Line
g-Thermostat Switch 22-Heater Valve Control and Cable
lo--Heater Valve 23-Heater Inlet Hose to Heater
11 -Compressor Valve
12-Compressor Manifold 24-Heater Valve

Legend for Fig. 1A

Litho in U.S.A.
JO 750 Crawler Bulldozer System Testing
TM- 1136 (Nov-75) Heating and Air Conditioning

AIR CONDITIONING SYSTEM I

HEAT IN CAB AIR IS

ABSORBED BY THE GAS
AS AIR PASSES OVER
i THE EVAPORATOR.
I

I TCMDEPP~TIIRF HEAT FROM GAS IS GIVEN

iiF TO OUTSIDE AIR PASSING
CONDENSER THRO,UGH CONDENSER CORE.

RECEIVER DRYER

/
of-7

-WITH SERVICE

i=k --I-
v

SIGHT
GLASS
FILl

HIGH PRESSURE LIQUID LOW PRESSURE LIQUID

HIGH PRESSURE GAS

TEMP. SENSING TUBE GAS

T4 3817N

Fig. P-Schematic of Basic Air Conditioning System

GENERAL INFORMATION transferred to the cooler outside air being forced

through the condenser core. Because of this the re-
Refer to Fig. 2, and note that the compressor takes
frigerant gas cools enough to change into a liquid (still
low pressure refrigerant from the evaporator and com-
under high pressure).
presses it to a high pressure. Increasing the pressure
of the refrigerant causes its boiling point to rise to a
The high pressure liquid then moves through the
temperature higher than that of the outside air.
receiver-dryer, where moisture, acids, or solids are
removed by a special filter. The receiver-dryer also
As the high pressure gas moves through the
acts as a storage reservoir for refrigerant until needed
condenser, heat is removed from the gas and
by the evaporator.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9031-6 Heating and Air Conditioning TM- Il.36 (Nov-75)

The evaporator is where the actual cooling and is clamped to the evaporator outlet pipe and is well
drying of warm, moist cab air takes place. The flow of insulated from outside heat sources. Too little or too
refrigerant entering the evaporator is regulated by a much refrigerant moving through the expansion valve
diaphragm-type valve, called an expansion valve. This into the evaporator, will limit the cooling efficiency of
valve.uses an orifice to reduce the flow of high pres- the system.
sure liquid refrigerant into the evaporator, causing the
refrigerant pressure and temperature to drop. If too little refrigerant moves through the expansion
valve, the refrigerant gas will become too hot, permit-
Warm cab air, pulled over the evaporator by the ting the gas in the sensing bulb to expand enough to
pressurizer blowers, gives up its heat to the cooler open the expansion valve.
refrigerant, thereby cooling the air and causing the
refrigerant to boil, or vaporize. Because the pressure in If too much liquid refrigerant moves through the
the evaporator is low, the boiling point of the refrigerant expansion valve, some of the liquid will still be va-
is also low. porizing as it leaves the evaporator. This lowers the
temperature at the outlet, which in turn lowers the
Moisture (in the air) is collected on the evaporator temperature of the gas in the sensing bulb and allows
core during the cooling process and drained away. the expansion valve to close.
With the cab air cooled and dehumidified, the desired
effect has been produced and the cycle is now com- The thermostatic temperature control switch is a
plete. rotary type switch that is connected to a temperature
sensing tube inserted in the evaporator core. The
The expansion valve and a thermostatic tempera- switch end of the gas-filled sensing tube has a dia-
ture control switch are the two controls used in the air phragm which controls two external contacts wired to
conditioning system to maintain the proper cooling the compressor clutch. When the cab air needs to be
balance. cooled, corresponding to the preselected control set-
ting, the compressor will turn on. The compressor will
A temperature sensing bulb is connected to continue to function until the selected temperature is
the expansion valve by means of a capillary tube reached.
filled with a low pressure gas. The sensing bulb

Litho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Heating and Air Conditioning 9031-7

AIR CONDITIONING SYSTEM

DIAGNOSIS AND TESTING
1 Visual Preliminary Checks 6. Check temperature of discharge air from air
ducts. Hold thermometer in air duct until lowest
Before attempting to service a suspected compo-
reading is obtained.
nent failure in the air conditioning system, make the
a. If ambient temperature is above 80°F (27”C),
following checks:
the duct air temperature must be 25 to 30°F
(14 to 17°C) below ambient temperature.
1. Make sure heater valve is closed.
b. If ambient temperature is below 80°F (27°C)
the duct air temperature must be less than
2. Adjust compressor drive belt to 15 ibs. (67 N) (7
50°F (10°C).
kg) tension with l/4 inch (6.35 mm) deflection.
7. If unit does not operate as described, refer to
Diagnostic Flow Chart and Operational Diagnos-
3. Check the condenser core to see that it is not
tic Chart.
partially or completely plugged with dirt or trash. Clean
with compressed air or water when needed.
Diagnosing Malfunctions

q
I
4. Check evaporator core for plugging. If the system is still not working correctly after mak- ’ I
ing the above checks, refer to Figs. 3 and 4 and use the
5. Check air intake filters for plugging. following list of problems and possible causes as a
guide to diagnose the malfunction.
6. Check routing of hoses to be sure they are not
rubbing against any sharp corners or rough surfaces. Compressor Drive Belt Slips
Belt not tight enough
Visual Operating Checks Compressor “frozen-up”
Excessive head pressure (overcharge of refrigerant)
The second part of the visual system inspection
Plugged condenser
requires an operational check of the system, if it is
Inoperative condenser fan.
operable.

System Cooling Intermittent at -80°F (27°C)

NOTE: Ambient air temperature must be at least
Outside Air Temperature
609 (16%).
Receiver-Dryer cannot handle moisture in the sys-
tem
1. With key switch on, operate blower switch in all
positions. Observe fan speeds and air volume
Outlet Air Temperature Too Warm
from air ducts.
Not enough refrigerant
Expansion valve defective
2. With key and blower switches on, turn tempera-
Temperature control switch defective
ture switch toward maximum cooling and listen
Heater valve not working correctly
for audible “click” from compressor clutch and
condenser fans (if equipped) should operate.
High Compressor Discharge Pressure
Refrigerant overcharge
3. Turn heater valve to closed position.
Air in system
Condenser coil plugged
4. With blower switch at high speed and tempera-
Restriction in compressor discharge hose
ture switch at maximum cooling, operate engine
Restriction in condenser outlet pipe
at 2000 rpm.
Restriction in receiver-dryer
Filters or screens plugged
5. After three minutes, observe sight glass for bub-
bles. Bubbles may be present immediately after
Low Compressor Discharge Pressure
compressor cycles on. If occasional bubbles or a
Insufficient refrigerant
constant stream of bubbles are observed while
Compressor belt slipping
the compressor is on, refer to Operational Diag-
Magnetic clutch slipping
nostic Chart, page 9031-10.

Litho in U.S.A.
 90 System Testing JD750 Crawler Bulldozer
9031-8 Heating and Air Conditioning TM- 1136 (A pr- 79)

High Suction Pressure Compressor Magnetic Clutch Inoperative

Loose compressor belt Open connection

Magnetic clutch slipping Open thermal fuse
Loose expansion valve temperature bulb clamp Open field coil in clutch
Expansion valve sticking open Defective thermostat switch
High refrigerant charge Closed superheat switch
Air in system
Noisy Compressor/Magnetic Clutch
Low Suction Pressure
Defective bearing in pulley
Shortage of refrigerant Broken mounting bracket
Restriction in lines or receiver-dryer internal failure in process
Air intake filters or screens plugged
Expansion valve temperature bulb charge low or lost Compressor Magnetic Clutch Slips
Expansion valve @ugged with dirt or corrosion
Low voltage to clutch
Expansion valve capillary tube broken
Excessive load caused by high discharge pressures
Moisture freezing in expansion valve
Warped drive plate
Blower fans inoperative
Oil on clutch surfaces

Icing of Evaporator
Blower Motors Inoperative
Thermostat tube in wrong area of evaporator core
Blown fuse
Loose electrical connection
Open circuit
Plugged air filter
Defective switch
Blower motor operating too slowly
Defective blower motor
1 Defective temperature control switch
Blower Speed Slow or Erratic

Motor shaft binding

Loose electrical connection
Defective switch

Litho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Aor- 79) Heatina and Air Conditionina 9031-g

I
1 PROBLEM jITH A/C 1

MAKE VISUAL PRELIMINARY CHECKS

t
MAKE VISUAL OPERATING CHECKS

t
MAKE OPERATIONAL TEST

(INSTALL TEST GAUGES. OPERATE ENGINE AT 2000 RPM, TEMP. CONTROL

SET FOR MAX. COOLING, AND BLOWER SPEED TURNED TO HIGH. OPERATE
SYSTEM FOR 10 MIN. AND INTERPRET GAUGE READINGS.)

FURTHER TESTING

a
lt

CCMPRESSOR ENGAGES, BUT TEMPERATURE

DOES NOT COOL OR CYCLE
TOO HIGH I

'I
CHECK FUSES AND CHECK SIGHT GLASS, CONDENSER,
ELECTRICAL CONNECTIONS EVAPORATOR AND CONDENSER FAN (IF APPLICABLE)
A

v
I I
.
SYSTEM CYCLES AND COOLS
AT SPECIFIED TEMP. I NO BUBBLES
IN SIGHT GLASS
(SYSTEM MAY BE FULLY CHARGED OR
'I EMPTY. CHECK TEMP. OF HOSES AT I

Ip!iFsEFI SIGHT GLASS

1 MAKE OPERATIONAL TEST 1

T54017N

fig. 3-Diagnostic flow Chart

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9031-10 Heating and Air Conditioning TM- 1136 (Apr- 79)

Low High
Sight Suction Receiver- Liquid Discharge Discharge
CONDITION Side- Side-
Glass Line Drier Line Line Air
PSI PSI

1 PROBLEM

------I
-I---
Very Very Slightly
cool Warm /
Lack of R-12 Clear
Low Low

Loss of R-12 Low Low Bubbles

-I-
Normal
Air in System Occasional
(won't Normal Bubbles
(Small Amount)
drop)

Compressor
High Low Clear
Failure

Clear to Slightly
Condenser
Uigh High Occasional Cool to Hot j Hot Hot Warm
Malfunction
Bubbles Warm

Moisture
in System Clear

Bubbles

Valve Stuck High High Clear

Expansion Sweating
Slightly
Valve Stuck Low Low Clear Or Frosting Warm Warm Hot Cool
Closed Heavily At
Valve Inlet

Liquid
High Side Clear
Restriction

Gas High lear to

Side iial / High ccasiona‘
Restriction ubbles

Fig. 4Operational Diagnostic Chart

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Heating and Air Conditioning 9031-11

OPERATIONAL TEST Operational Temperature-Pressure Chart

Use the operational temperature-pressure chart as Outside Air 80 to 110°F

a guide in making the operational test. Compare test Temperature (27 to 43°C)
results with the average values given in the chart. See
Group 9035 for testing equipment. Compressor Discharge 125 to 250 psi
Pressure (8.6 to 17 bar)
1. Connect the test gauges as instructed in SYS- (8.8 to 18 kg/cm2)
TEM SERVICE, page 90-9031-12.
Compressor Suction 5 to 30 psi
2. Start engine, run at 1900 rpm with blower speed Pressure (0.3 to 2 bar)
on high, and temperature control set for maximum (0.3 to 2 kg/cm2)
cooling. Run system for 5-10 minutes before making
tests. Air Outlet 25 to 30°F (14 to 17°C)
Temperature below ambient if
3. Insert a thermometer next to one of the air outlets ambient is above
and record the air temperature. 80°F (27°C).

q
4. Observe sight glass for bubbles. Bubbles should Less than 50°F
disappear within 15 seconds after the compressor (10%) if ambient is ’ ’
clutch engages. below 80°F (27°C).

5. Observe and record pressure gauge readings. Refer to “Fundamentals of Service,” FOS

6. Evaluate all temperature and pressure readings

based upon the humidity of the outside air. Air that is
humid when being cooled, will increase the load on the
evaporator and cause higher head pressures than
clms

0
Manual-57B, Air Conditioning, for additional
diagnosis and testing information.

ELECTRICAL TESTING
when cooling relatively dry air. Discharge pressure
readings that do not fall within the ranges given in the If an electrical component of the air conditioning
Condenser Air inlet Temperature-Normal Compressor system does not operate, test as described in Group
Discharge Pressure chart should be investigated. 9015.

Litho in U.S.A.
90 -- System Testing JD750 Crawler Bulldozer
9031-l 2 Heating and Air Conditioning TM- 1136 (Apr- 79)

,SYSTEM SERVICE

a Safety Precautions
The left-hand gauge measures the compressor
suction pressure (low pressure side). The gauge is
graduated from 0 to 250 psi (0 to 17 bar) (0 to 18
Refrigerant-12 by itself is harmless and nonpoison-
kg/cm*), and 0 to 30 inches (0 to 1015.9 mbar) of
ous; however, special precautions should be taken
vacuum in the opposite direction.
when servicing any refrigerant air conditioning system
or handling refrigerant containers. The right-hand gauge measures the compressor
discharge pressure (high pressure side). This gauge
1. Do not expose eyes or skin to liquid refrigerant.
shows pressures from 0 to 500 psi (0 to 34 bar) (0 to 34
Always wear safety goggles when opening refrigerant
kg/cm*).
lines. Liquid Refrigerant-12 has a boiling temperature
of approximately -21°F (-30°C) at sea level; there- Each gauge has an outlet for attaching a hose to its
fore, serious injury could result if liquid refrigerant respective connection on the compressor service
contacts the eye or skin. If Refrigerant-12 strikes the valves. (See Special Tools.)
eye, call a doctor IMMEDIATELY and:
The center port of the gauge set is used for charging
Do not rub the eye. Splash cold water on the eye to or evacuating procedures and is connected to the
gradually raise the temperature of the contacted area. vacuum pump or the Refrigerant-12 container.

Obtain treatment from a physician as soon as pos-

sible.

If the liquid refrigerant comes in contact with the

skin, treat the injury as though it were frozen or frost-
bitten.

2. Do not discharge refrigerant into an area where

there is exposed flame. Heavy concentrations of re-
frigerant-12 contacting an open flame will produce a
poisonous gas.

3. Do not weld or steam clean near or on an air

conditioning system. Excessive pressure could be
built-up within the system.
4. Do not subject containers of Refrigerant-12 to
temperatures above 125°F (52°C). Also, during the
charging process, water for heating the refrigerant
containers should never exceed 125°F (53°C). Higher
temperatures will cause excessive container pres-
sures.
T5.2407

5. All charging and leak testing should be per- l-Low Side Manifold 4-Compressor Service
formed in a well-ventilated area. Hand Valve Valve Low Side
2-High Side Manifold 5--Charging Hose
6. Before loosening a refrigerant fitting, cover the Hand Valve Can Tap
connection with a cloth. 3-Compressor Service ‘I-Suction Side Hose
Valve High Side &Discharge Side Hose I
7. When charging system with engine running, be g-Gauge Set
sure high pressure gauge valve is CLOSED.
I

A
Fig. 5-Typical Manifold Gauge Hookup
CAUTION: A refrigerant container tap can-
not be safely removed from a partially filled
This gauge set is commonly referred to as a man-
container.
ifold gauge set. This term is widely accepted in the air
conditioning industry. Fig. 5 illustrates a typical man- 1
Pressure Gauges
ifold gauge hookup with refrigerant.
The gauge set shown in Fig. 5 is an important tool
for servicing an air conditioning system. It is used when
evacuating, charging, or “troubleshooting” the system.

Litho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Am- 79) Heating and Air Conditioning 9031-13

Installing Pressure Gauges Connect the hoses to the manifold gauge set ports

1 Before 307632, the compressor utilized the type of

and to the gauge ports of the compressor (Fig. 6). The I I
high pressure gauge hose (red) must be connected to
valve which may be backseated. This allows the com-
the compressor discharge service valve. Connect the
pressor to be isolated from the rest of the system.
low pressure gauge hose (blue) to the suction side
service valve. Tighten hoses finger tight only.
After 307631, the compressor uses Schrader-type
service valves. A special fitting is necessary to connect
Mid-position service valves by turning each clock-
gauge hose to the Schrader-type service valve. When
wise 1 to l-1/2 turns.
the fitting is connected to the valve, a pin depresses
the center of the valve to allow pressure readings on
After 307631
the gauge. The removal of the special fitting closes the
valve. This type of valve does not allow the compressor Make sure both hand valves on manifold gauge set
to be isolated. are closed.

Before 307632 Connect the hoses to the manifold gauge set ports.

Before connecting manifold gauge hoses to the

Remove the gauge port caps from the compressor
compressor service valves, be sure that the valves are
valves.
correctly positioned (back seated).
Install the discharge hose to the discharge valve (4,
Remove the service valve caps (2, Fig. 6) from the
Fig. 6). Install the suction hose to the suction valve (5).
compressor service valves.
Tighten hoses finger tight only.
To backseat both service valves,. (Fig. 6) (which is
normal operating position), turn the adjusting stems all
Discharging the System
the way counterclockwise. This shuts off the refrigerant
to the gauge ports from the compressor. Close both
manifold gauge set ports by turning both valves clock- A CAUTION: The refrigerant in the system
must be discharged before any lines or
1 wise (1 and 2, Fig. 5). units in the system are disconnected. Follow all
recommended safety precautions on page 90-
9031-12 while performing work on the system.

Connect the manifold gauge set to the compressor

refrigerant valves as previously instructed.

SLOWLY open the high pressure discharge gauge

valve to allow refrigerant to escape from the compres-
sor.

Next, SLOWLY open the low pressure gauge valve

to allow the remaining refrigerant to escape from the
compressor. This slow depressurization is to prevent
the loss of refrigerant oil from the compressor. If oil
comes out with escaping refrigerant, close gauge valve
slightly to reduce the flow.
l-Compressor e-Discharge Valve
2-Service Valve Caps (High Pressure)
Evacuating the System
3-Gauge Port Caps S-Suction Valve
(Low Pressure) After the system has been discharged and opened
for service, air will enter the openings before they can
Fig. 6-Compressor
be capped. To remove this air (along with the moisture
it contains), the system must be evacuated. Evacua-
tion is the process whereby all air is removed from a
system to the extent that a vacuum is created. Do not
discharge the refrigerant through the vacuum pump.

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9031-14 Heating and Air Conditioning TM- 1136 (Apr- 79)

Always evacuate the system to remove air and Start the vacuum pump with both gauge manifold f
moisture, whenever the system has been discharged, valves and pump exhaust open.
for the following reasons:
Evacuate to 28 inches (69 mbar) of vacuum.

1 - When moisture and refrigerant oil combine, If 28 inches (69 mbar) of vacuum cannot be obtained
sludge is formed. Sludge does not permit mov- in less than five minutes, a severe leak exists. If this
ing parts to be adequately lubricated. occurs, check all connections for leaks and repeat.

Close both gauge manifold valves to hold vacuum in

2 - When moisture and refrigerant combine, hy-
the system. Observe the gauge to determine if there is
drofluoric and hydrochloric acids are produced.
any leakage. If the vacuum drops more than 1 inch
These acids are highly corrosive to metal sur-
(2.48 mbar) within five minutes, there is a leak in the
faces and leakage eventually develops.
system.

Check all refrigerant line and component fittings for Charge the system with 0.5 to 1 .O lb (0.25 to 0.5 kg)
tightness. (gas or liquid).
IMPORTANT: If system is charged with a liquid,
charge the high side only.
NOTE: A minimum static system pressure of 5Opsi
(3.4 bar) is required for leak testing.
Using a calibrated leak detector, check all hoses
connections and cores by running the probe com-
pletely around the connections and components at the
rate of approximately one inch (25 mm) per second.

Correct all leaks before proceeding.

l-To Condensor 5-Pressure Gauge Set
2-Compressor 6-Vacuum Pump Discharge refrigerant in system.

A
~-LOW Pressure Gauge 7-From Evaporator
CAUTION: When liquid refrigerant (R-12)
4-High Pressure Gauge
enters atmospheric pressure, its tempera-
fig. 7-Evacuating System ture will immediately drop to -22°F (-30°C). Follow
all safety precautions listed at the beginning of this
Connect test hoses of gauge manifold to compres- group.
sor test fittings.

Connect a vacuum pump to center hose of gauge

manifold (Fig. 7).

NOTE: Pump must be capable of pulling 28.6

inches (71 mbar) of vacuum (sea level). Deduct one
inch (2.48 mbar) of vacuum for each 7000 feet (305 M)
above sea level.

IMPORTANT: DO NOT operate the compressor

during evacuation.

Mid position high and low side compressor service

valves ( -307631).

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Heating and Air Conditioning 9031-15

Do not return this refrigerant into charging contain- Install container tap on single container of refriger-
ers. Install a new receiver-dryer. Make sure the sight ant.
glass is installed toward the expansion valve.
Resume evacuation.
Evacuate the system for a minimum of 30 minutes
after 29 inches (72 mbar) of vacuum is reached.
Shut off gauge manifold valves. Then shut off vacu-
um pump.
The system is now ready to be charged.

Charging The System

The system should be charged with refrigerant only
after it has been leak tested and evacuated. It is
important to add only the specified quantity of refriger-
ant.

A CAUTION: Follow all previously

safety precautions for handling Refriger-
given

ant-12 (page 90-9031-l 2).

l-Piercing Needle 3-Lever to Secure
2-Seal Container to Tap

Fig. B-Typical Refrigerant Container Tap

1

A CAUTION: Before tapping refrigerant con-

tainer, be sure tap has a good seal. A poor
seal will allow refrigerant to leak to atmosphere
endangering service technician.

Secure container tap to refrigerant can before

piercing container. The refrigerant container tap
cannot safely be removed from a partially filled
container.

Connect charging hose to both gauge center port

and container tap before piercing container.

P43822N

l-From Evaporator %-Can of Refrigerant

2-Compressor 6-Charging Hose
~-TO Condenser “I-Low Side Gauge
4-Pressure Gauge Set &High Side Gauge

Fig. b-Charging the System

Litho in U.S.A.
 90 System Testing JD750 Crawler Bulldozer
9031-16 Heating and Air Conditioning TM- 1136 (Apr- 79)

Close shut-off valve on container tap. Check refrigerant charge in system as follows.

Pierce can with mechanism which is part of con- Watch for bubbles in sight glass.
tainer tap.
NOTE: Excessive head pressure with a normal low
I Install charging hose to container tap. side pressure indicates an overcharge of refrigerant or
air in the system. Compressor may or may not be
Loosen charging hose at center connector on gauge noisy.
manifold.
If the refrigerant is low, the sight glass will show
Crack container tap shut-off valve to purge air from foam and bubbles.
I charging hose.
When the refrigerant is correct, the sight glass will
Tighten charging hose connection on gauge man- be clear.
ifold.
ADDING REFRIGERANT-1 2
Open high side gauge manifold hand valve. TO SYSTEM
Small amounts of refrigerant may have to be added
Open shut-off valve on container tap.
to the system to replace what was lost by leaks, or
opening of system for service. Check the compressor
Turn over container to allow refrigerant to move into
I high side of system (see Fig. 8).
oil level (see page 18-1830-16) and add oil if neces-
sary, before adding refrigerant.

IMPORTANT: DO NOT OVERFILL SYSTEM.

Capacity of the system is 3-l /2 Ibs. (1.6 kg).

Close high side gauge manifold hand valve.

Check for leaks and correct if necessary.

Start engine and adjust throttle to 1900 rpm

Adjust air conditioning controls for maximum cool-

ing.

Open low side gauge manifold hand valve to allow

refrigerant to be drawn into system (refer to ADDING
REFRIGERANT-12 TO SYSTEM, this page).
l--Refrigerant Can 2-Open Low Side (Not
Watch sight glass until bubbles disappear. (Inverted) over 40 psi (3 bar)
(3 kg/cm2)

fig. lo-Adding Refrigerant with System

in Operation

Litho in U.S.A.
 JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Heating and Air Conditioning 9031-17

Connect gauges to system (Fig. 5). IMPORTANT: Be sure that temperature is 80°F
(27°C) or above and that compressor and system is
Connect hose to R-12 source and bleed air from warmed up to aid in vaporizing refrigerant.
manifold gauge center hose.
NOTE: In cool weather (below 80°F [27”CI), warm
the refrigerant container, not above 125°F (52°C) to
Set air conditioning controls for maximum cooling
help vaporize the refrigerant before it enters the sys-
and operate engine at 1900 rpm.
tem.
Open low side manifold valve. Work low side service valve or valve on refrigerant
container to regulate low side pressure not to exceed
Invert a 15 oz. (444 mL) can and open valve not to 40 psi (3 bar) (3 kg/cm2) to prevent liquid entering the
I exceed 40 psi (3 bar) (3 kg/cm*) on low side gauge. compressor.
Watch sight glass until bubbles disappear.
IMPORTANT: Be sure that refrigerant enters
system only as a VAPOR. Liquid entering the Add, an additional 314 lb. (0.34 kg) of refrigerant.
compressor can damage internal parts. Be sure to
Close low side manifold valve to check for complete
regulate the valve on the container or low side
charge.
valve so that the 10’~ side reading will not exceed
40 psi (3 bar) (3 kg/cm2). This will assure that High side gauge will show normal reading of head
refrigerant in the hose has vaporized before enter- pressure in relation to ambient temperature.
ing the compressor.
Sight glass will be clear of bubbles.

Close valve on refrigerant container.

Check system for leaks (see page 18-1830-18).

CONDENSER AIR INLET TEMPERATURE-NORMAL

COMPRESSOR DISCHARGE PRESSURE
(For Refrigerant R-12)

Ambient Temp. Normal High Side Pressure

“F “C PSI bar kg/cm2

80 27 125 to 155 9 to 11 9 to 11

90 32 145 to 175 10 to 12 10 to 12

95 35 170 to 200 12 to 14 12 to 14

100 38 190 to 220 13 to 15 13 to 15

105 41 205 to 230 14 to 16 14 to 16

110 43 220 to 250 15 to 17 15 to 18

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9031-18 Heating and Air Conditioning TM- 1136 (Apr- 79)

Isolating Compressor From System NOTE: Bleed refrigerant slowly to prevent pulling oil
( -307631) from compressor.

Before 307632’ the compressor on the JD750

Remove service gauges from service valve.
Crawler may be isolated and-refrigerant retained in the
system while service work is be.ing performed on the
Remove service valve from compressor.
compressor or the machine engine. After 307631, the
compressor can’t be isolated from system.
Perform service work required. Refer to Group 1830
to remove and repair air conditioning components.
Connect gauges to system. (Refer to page 9031-
13.)
To install compressor, use the following procedure:

Adjust air conditioning controls for maximum cool-

Install service valve on compressor using new O-
ing.
rings.

Operate system for 10 or 1’5 minutes.

Purge air from compressor by cracking low side
service valve for 3 seconds with low side hose con-
Slowly close (front seat) low side service valve until
nector capped and high side hose connector open.
low side gauge reads 0 psi (0 bar) (0 kg/cm2).
Install gauges to service valve connectors as
Turn off machine engine.
directed on page 9031-13.

Completely close (front seat) low side service valve.

Mid-position service valves ( -307631).

Close (front seat) high side service valve.

Purge air from hoses.

Bleed refrigerant from compressor by cracking low

Adjust controls for maximum performance.
side hand manifold until both gauges read 0 psi (0 bar)
(0 kg/cm2).
Test the system by conducting operational test
(9031-I 1).
NOTE: If there has been an internal failure, dis-
charge, flush and purge the system as described on
pages 9031- 13 and 903 1- 19 respectively.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Heating and Air Conditioning 9031-19

LEAK TESTING NOTE: Do not flush components through

Schrader-type service valves. A substantial pressure
Leaks can be detected with an electronic type de-
drop occurs across valve which prevents flushing of
tector. The location of a leak can also often be detected
larger contaminants.
by an oily film at the source of the leak. A soap and
water solution may also be used.
Components can be flushed on the unit (except
Additional information on leak detectors is compressor) with R-11 as follows.
m given in “Fundamentals of Service” General
Manual, Air Conditioning. Follow instructions Isolate the compressor, receiver-drier and expan-
Cl 0 of manufacturer when using electronic de- sion valve from the system.
tector.
Flush all components INDIVIDUALLY.
When the source of a leak has been found and
corrected, the system should be evacuated and
Flushing system components can be done by con-
charged with l/2 lb. (227 g) of refrigerant. Again test
necting a refrigerant supply container to the compo-
for leaks. If no leaks are detected, charge system with
nents to be flushed. Turn the refrigerant container
an additional 3 Ibs. (1 kg) of refrigerant.
upside down, open the container valve and allow liquid
refrigerant to flow through each component. Be sure
FLUSHING SYSTEM COMPONENTS
that the components to be flushed are supported ade-
It is essential that the system components be quately, in order that the refrigerant and contaminants
flushed if there has been an inside failure, regardless passing through will be directed into an area where
of the cause. Otherwise, metal particles or other types refrigerant (R-12) at -22°F (-30°C) will not do any
of contamination may circulate in the system, and harm.
create a restriction at the inlet screen of the expansion
valve. Remove receiver-dryer from system. Receiver-dryer
should be replaced with new one prior to evacuation.
NOTE: Flushing the system with R-l 1 (Flushing
Do not flush new receiver-dryer.
Solvent) is recommended because it is safer and more
effective than R-12.
When flushing the evaporator, disconnect the ex-
If R-12 is used for flushing the system, note the pansion valve. it may be necessary to back flush
following: (flushing in reverse of normal flow) to aid in removing
the contaminants.
A CAUTION: When liquid refrigerant (R-12)
enters atmospheric pressure, its tempera-
Remove the compressor, drain the oil, add R-11
ture will immediately drop to -22°F (-30°C). Follow
through the drain port and plug the port, shake the
all safety precautions listed at the beginning of this
compressor and drain the R-l 1.
group.

Flushing the system with R-l 1 provides the follow- Purge the system as described in Purging The Sys-
ing advantages over R-12: tem, page 9031-20.

1 - R-l 1 remains in a liquid state up to 76°F (24°C).

2 - R-l 1 will not freeze moisture in the system

above 32°F (0°C). (R-12 will freeze moisture
with zero pressure.)

3- R-11 moves moisture and debris out of the

system more rapidly above 32°F (O’C).
4 - R-11 will not freeze your skin when in direct
contact. (R-12 freezes on contact.)

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9031-20 Heating and Air Conditioning TM- 1.136 (Aor- 79)

Purging The System Inspecting Refrigerant

Hoses and Tubing
Purge the system with Dry Nitrogen or R-12 after
flushing with R-11 or whenever a component is re- When a component is disconnected from the sys-
placed. tem, special care should be given to inspecting hoses
and tubing for moisture, grease, dirt, rust, or other
CAUTION: When liquid refrigerant (R-12) unwanted foreign material. If such contamination is
a enters atmospheric pressure, its tempera- present in hoses, tubing, or fittings and cannot be
ture will immediately drop to -22°F (-30°C). Follow removed by cleaning, then the parts should be re-
all safety precautions listed at the beginning of this placed.
group.
Fittings that have grease or dirt on them should be
Purge the system with 40 to 50 psi (2.8 to 3.4 bar) wiped clean with a cloth dampened with alcohol.
(2.8 to 3.5 kg/cm2) flow at the point of gas entry as Chlorinated solvents (such as trichlorethylene) are
follows: contaminants, and should not be used for cleaning.

1 - Purge replacement components individually for To assist in making leak-proof joints, use a small
15 to 30 seconds. amount of clean 525 viscosity refrigerant oil on all hose
and tubing connections. Dip O-rings in 525 oil before
2 - Connect each component after purging. assembling.

3- Purge the total system through the compressor IMPORTANT: Hoses used for air conditioning
high side fitting, toward the condenser, re- systems contain special barriers in their walls to
ceiver-drier, expansion valve, evaporator and prevent migration of refrigerant through the walls.
discharge from the compressor low side fitting. DO NOT use hydraulic hose as replacement hose
in the air conditioning system. Use ONLY certified
Add compressor oil to the system just flushed and hose meeting SAE 5516 requirements.
purged as shown below:

Compressor Oil . . . . . . . . . . . . . . . . . . . .525 viscosity

Compressor (New or
rebuilt) . . . . . . . . . . . . . . . . . 11 fluid oz. (326 mb)

Use NEW OIL only.

Evacuate the system before charging the system.

Refer to page 9031-13.

Litho in U.S.A.
JO750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Specifications and Special Tools 9035-l

Group 9035
SPECIFICATIONS AND SPECIAL TOOLS
ENGINE
SPECIFICATIONS AND TORQUE VALUES

Basic Engine Minimum compression reading. . . . . . . . . . . 350 psi

(24 bar) (25 kg/cm2)

The most important factor in compression readings

is the difference between cylinders. This difference
should be no more than 50 psi (3 bar) (4 kg/cm2)

Engine Lubrication System Oil pressure at 2375 rpm with engine at

normal operating
temperature . . . . . . . . . . . . . . . .50 + 15 psi
(3 t 1 bar) (3 + 1 kg/cm2)
Engine Cooling System
Alternator and Fan Belt Adjustment

With gauge (alternator)

(initial) (strand tension). . .. .. 135 2 5 Ibs.
(600 c 22 N) (61 -c 2 kg)
With gauge (fan belt)
(initial) (strand tension). . . . .. ... 100 ? 5 Ibs.
(445 t 22 N) (45 ” 2 kg)
(after 10 minutes of
operation) (strand tension) . 90 5 5 tbs. minimum
(400 r 22 N) (41 r 2 kg)

Without gauge (alternator) . . . .5/8-inch (16 mm)

Fuel System flex at 25 Ibs. force
(111 N) (11 kg)
- (fan) . . . . . . . . . .5/8-inch (16 mm)
flex at 25 Ibs. force
(111 N) (11 kg)
Fuel supply pump at low idle
pressure. . . . . . . . . . . . . . . . . . . 2 to 2.5 psi
(0.1 to 0.2 bar) (0.1 to 0.2 kg/cm2)

Injection pump cam advance

DM4627MD2916
Total advance movement . . . . . . . . . . . .6 _t l/2”
Advance at 600 to 1000 rpm (no load) . . . 1”

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90 System Testing JD750 Crawler Bulldozer
9035-2 Specifications and Special Tools TM- 1136 (A pr- 79)

ENGINE
SPECIFICATIONS AND TORQUE VALUES-Continued

Speed Control Linkage Fast idle. . . . . . . . . . . . . . . . . . . . . 2300 to 2320 rpm

Slow idle* . . . . . . . . . . . . . . . . . . . . 975 to 1000 rpm

Air Intake System Air restriction indicator shows red when water vacuum
gauge reads . . . . . . .22.5 to 27.5 inches of water
(56.0 to 68.5 mbar)

Air cleaner restriction

at 2200 rpm . . . . . . . . . . . . . . .3 inches of water
(7.5 mbar)

*Disconnect clutch engaged

Litho in U.S.A.
JD750 Crawler Bulldozer Sys tern Testing 90
TM-7 136 (Nov-78) Specifications and Special Tools 9035-3

ENGINE

SPECIAL TOOLS

Essential Tools

Tool Tool Number Use

Basic Engine 70-314” Compression :Gauge Adapter - To

check diesel engine compression.

Fig. l-Compression Gauge Adapter

70-7003* Compression Gauge - To check

diesel engine compression.

l”27985N
*Available from: Bacharach instrument Co.
Fig. Z-Compression Gauge 625 Alpine Drive
Pittsburgh, Pennsylvania 15238

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9035-4 Specifications and Special Tools TM-l 136 (NOW78)

ENGINE

SPECIAL TOOLS-Continued

Essential Tools-Cont.

Tool Tool Number Use

Engine Lubrication System ----- Pressure Gauge - To check oil and

fuel pressures.

Fig. 3-Pressure Gauge

Engine Cooling System

(Not Illustrated) Radiator Pressure Tester - To
check radiator for leaks.

JDST-28 Belt Tension Gauge - To check--

tension of belts.

T62057N

Fig. 3A-Belt Tension Gauge

Fuel System 19918 Timing Window - To adjust injection

pump cam advance.

Fig. 4-Injection Pump Timing Window

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Specifications and Special Tools 9035-S

ENGINE

SPECIAL TOOLS-Continued

Essential Tools-Cont.

Tool Tool Number Use

Speed Control Linkage (Not Illustrated) Tachometer - To check en-

gine speeds while adjusting
Convenience Tools speed control linkage.

Engine Cooling System

(Not Illustrated) Fan Belt Tension Gauge - To
check fan belt tension.
Air intake System

D-05022ST Water Vacuum Gauge - To

‘I
q
(Formerly check air vacuum.
JDST-11)
I

Fig. &Water Vacuum Gauge and Fittings

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9035-6 Specifications and Special Tools TM- 1136 (Apr- 79)

ELECTRICAL SYSTEM

SPECIFICATIONS AND TORQUE VALUES

Starting Circuit Test Valuk

Test No. 1. ........ . .... . 20 to 24 volts

Test No. 2.. . . . . . . . ....... . . 20 to 24 volts
Test No. 3 ... ... . ........ . . 20 to 24 volts
Test No. 4. . . . . . . . . . . . . . .. .. .Zero volts
Test No. 5 ............. .... . . 20 to 24 volts

TM226111

l-Battery Disconnect S-Key Switch

Z-Batteries 7-Start Switch
3-Starting Motor &Voltmeter
4-Starting Motor Solenoid %-Start Circuit Relay
5-Main Circuit Breaker lO-Neutral Start Switch

Fig. 6 - Starting Circuit Test Points

bitho in U.S.A.
JD750 Crawler Bulldozer 3pi~ttt I caring
TM- 1136 (Nov-75) Specifications and Special Tools

ELECTRICAL SYSTEM
SPECIFICATIONS AND TORQUE VALUES-Continued
Starting Circuit Test Values-Continued
l-------1
I . I
I High Resistance Test Values
I

Test Points Maximum Voltage Reading

A-F 0.2
B-C 0.2
C-D 1.0
B-E 1.2

-L
=
R-RED
B-BLACK
W-WHITE
OR-ORANGE

T44217N
l-Battery Disconnect GKey Switch
2-Batteries 7-Start Switch
3-Starting Motor &Voltmeter
4-Starting Motor Solenoid g-Start Circuit Relay
5--Main Circuit Breaker IO-Start Safety Switch

Fig. 7-Starting Circuit - High Resistance Test

,’

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9035-8 Saecifica tions and Special Tools TM-l 136 (Nov-75)

ELECTRICAL SYSTEM

SPECIFICATIONS AND TORQUE VALUES - Continued

Charging Circuit Test Values

16 Amp Alternator - Without Cab

KEY OFF KEY ON KEY ON

I ENGINE OFF I ENGINE OFF ENGINE ON

OUTPUT
TERMINAL
26 VOLTS 26 VOLTS 27.5 VOLTS
TEST POINT
NO. 1

R-RED
OR-ORANGE
PU-PURPLE
GR-GREEN
OTEST POINTS
T44227N

l-Battery Disconnect &-Voltmeter

2-Batteries 7-Alternator
3-Starting Motor &Regulator
4-Main Circuit Breaker g--Resistance Wire
!&-Key Switch
Fig. 8 _ Charging Circuit Test points 42 Amp Alternator - With Cab

KEY OFF KEY ON KEY ON

ENGINE OFF ENGINE OFF ENGINE ON

OUTPUT
TERMINAL
26 VOLTS 26 VOLTS 27.5 VOLTS
TEST POINT
NO. 1

REGULATOR
TERMINAL 27.6 VOLTS
0 VOLTS 6.9 VOLTS
TEST POINT
NO. 2

Litho in U.S.A.
JD 750 Crawler Bulldozer System Testing 90
TM- 1136 (Nov-75) Specifications and Special Tools 9035-g

ELECTRICAL SYSTEM
SPECIFICATIONS AND TORQUE VALUES-Continued

Charging Circuit Test Values-Continued

High Resistance Test Values*

Test Points Maximum Voltage Readings

A-C 0.3 Volt
B-D 0.3 Volt
B-E 0.3 Volt

* 1O-amp charging rate

T44221N

l--Battery Disconnect Switch 7-Alternator

2-Batteries S-Regulator
3-Starting Motor g--Resistance Wire
Q-Main Circuit Breaker lo-lest Voltmeter
&Key Switch 1l-Ammeter
GVoltmeter

Fig. g-charging System High Resistance Test Points

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9035-10 Specifications and Special Tools TM- 1136 (Nov-75)

ELECTRICAL SYSTEM

SPECIFICATIONS AND TORQUE VALUES - Continued

Lighting Circuit Test Values

Voltmeter to Lamp Terminal

and Lamp Frame. . . . . . . . . . . . . . . . 20 to 24 volts

Voltmeter to Lamp Frame and

to Ground . . ~. . . , . . . ...... . . 0.1 volt

Voltmeter to Lamp Terminal and

to Battery Positive Post . . . . . . . 0.5 volt

Instrument and Indicator Circuit Test Val-

ues

Voltmeter and Hour Meter

Voltage at Gauge ... . . ~. . . . . . . . 24 volts

B-BLACK
Y-YELLOW
Indicator Lights
DKBL-DARK BLUE Voltage at Light Orange Wire. . ~ . ~. . 24 volts
TEST POINTS

IT T4423ON

l-Battery Disconnect 12-Transmission Filter

2-Batteries Pressure Switch
3-Starting Motor 13-Transmission Filter
4-Main Circuit Breaker Sending Unit
5-Key Switch l4-Equipment Hydraulic
g-Light Circuit Breaker Filter indicator
7-Light Switch Light
E-Canopy Lights l&-Equipment Filter
O--Gauge Lights Pressure Switch
1 O-Hour Meter M-Equipment Filter
1 l-Transmission Filter Sending Unit
Restriction Indicator 17-Voltmeter
Light

Fig. 70 - Lighting and Instruments and

Indicators Circuits Test Points

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Mar-78) Specifications and Special Tools 9035-11

ELECTRICAL SYSTEM
SPECIFICATIONS AND TORQUE VALUES - Continued

Miscellaneous Accessory Circuit Test Cigar Lighter and Windshield

Values Was her
Voltage at accessory . . . . . . . . . . . . . . 12 volts
All Accessories (except cigar
lighter and windshield washer)
Voltage at accessory ..... .. . . 24 volts

I----

0
1 BAT OfF j /'
R-RED
PU-PURPLE
B-BLACK
OR-ORANGE
LTBL-LIGHT BLUE

k
BL-BLUE
Y-YELLOW

24

Q 0

r3 TEST POINTS

2’57598N
l-Battery Disconnect 17-Dome Light
P-Batteries l&Rear Wiper
3-Starting Motor and lg-Air Conditioner
Solenoid Compressor ( -xXxXx)*
4-Main Circuit Breaker 2&Air Conditioner
5--Key Switch Thermostat ( -xXxXx) *
GWiper Fuse 21-Blower Motor Swiich
7-Wiper Switch 22-Blower Motors
3-Wiper 23-Cigar Lighter Resistor
g-Horn Switch 24-Cigar Lighter
1 O-Horn 25-Gab Circuit Breaker
1 l-Fuel Injection Pump 26-Resistor
12-Start Aid Switch 27-Windshield Washer Motor
13-Starting Aid Solenoid 2&Reverse Warning Switch
M-Start Safety Switch 29-Reverse Warning Alarm
15-Gab Relay *For A/C circuit after xxxxx,
16-Dome Light Fuse See Fig. 12.
Fig. 11 -Miscellaneous Accessories
Circuit Test Points

Lit/70 in U.S.A.
90 Sysfem Testing JD750 Crawler Bulldozer
9035-12 Specifications and Special Tools TM- 1136 (Mar-78)

ELECTRICAL SYSTEM
SPECIFICATIONS AND l&ORQlJE VALUES-Continued

Air Conditioning Circuit (XXXXX- )

OR
-------WI
I - I
&Y

-
IGN 1 OR T

-- J

TEST POINT
T56526N

l-Battery Disconnect Switch 7-Gab Circuit Breaker 18-Condenser Fan Motors

2-12 Volt Batteries 8-Air Conditioning Circuit Breaker i*Air Conditioning Relay
3-Starting Motor and g-Air Conditioning Fuse 17-Condenser Fan Motors
Solenoid W-Pressurizer Fuse 18-Compressor
4-Main Circuit Breaker 11-Pressurizer Switch 14-Thermal Fuse
EL-Key Switch 12-Thermostat
8-Gab Relay 13-High Temperature Switch
U-Plugged Condenser Indicator

Fig. ISTesting Air Conditioning Circuit

Air Conditioning Test Points . . 24 volts

Lifho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Specifications and Special Tools 903513

ELECTRICAL SYSTEM
SPECIAL TOOLS

Convenience Tools Tool No. Use

D-051 36ST Voltage Detector. . to test starting,

charging and accessoF?-circuits

Fig. 13-Voltage Defector

D-19001TT Voltmeter. . to test starting, charg-

ing and accessory circuits.

Ohmmeter. . . to check continuity

Ammeter. . to measure alternator

output current.

D-l 9005TT 100 Amp DC Current Shunt. . .to

extend the ammeter current
range.

Fig. 14-Voltmeter, Ohmmefer, and Ammeler

Litho in U.S.A.
90 System Testing JD750 Crawler Bulldozer
9035-l 4 Specifications and Special Tools TM- 1136 (Apr- 79)

HYDRAULIC SYSTEM (FLOW METER)

SPECIFICATIONS AND TORQUE VALUES

Bulldozer Hydraulic System

engine at W.O.T.
oil at 122°F (50°C)
system relief valve
setting . . . . . . . . . . . . . . . 2,000 + 175 - 0 psi
(13 800 + 1 200 - 0 kPa) (138 + 12 - 0 bar) I

circuit relief valve

setting . . . . . . . . . . . . . . . . . 2,250 + 175 - 0 psi
(15 500 + 1 200 - 0 kPa) ‘(155 + 12 - 0 bar) I

seconds
Cycle Times Min. Max.
Blade raise . . . . . . . . . . . . . . . . . . . . . . . . . . .2.5
Blade lower . . . . . . . . . . . . . . . . . . . . . . .2.5
(Power down)

Minimum Pump Output

2100 rpm., . . . . . . . . . . . 44 gpm (167 L/min)

at 600 psi (4 100 kPa) (41 bar) I
with 170
to 190°F (77 to 88°C)
oil.

38 gpm (144 L/min)

at ‘2000 psi (13 800 kPa) (138 bar)
with
170 to 190°F (77 to 88°C)
oil.

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- I 136 (Aor- 79) Specifications and Special Tools 9035-l 5

HYDRAULIC SYSTEM (ANALYZER)

SPECIFICATIONS AND TORQUE VALUES

System Relief Valve Test

Temperature of hydraulic oil ... 140 to 156°F
(60 to 66X)

Pressure setting of system relief valve

(at fast idle). . . . . . . . . . . . . . . . .2000 + 175 - 0 psi
(13 800 + 1 200 - 0 kPa)
(138 + 12 - 0 bar)

Hydraulic Pump Test

HYDRAULIC OIL TEMPERATURE: 140 to 1500F (60 to 66OC)

(temperature sensor on valve return line)

ORIFICE USED: 202842, 0.218 in. (5.54 nun)

(remove system relief valve from
control valve and install orifice)

SETTING OF THUMB DIALS: 030

TEST PRESSURE: 1500 psi (10 300 kpa)

(103 bar)(inlet to control valve)

MAXIMUM ENGINE RPM: 1950

,-'66088N

Fig. 75-Test Specifications

Circuit Leakage Test

Temperature of hydraulic oil . . . . . . 140 to 150°F
(60 to 66°C)

Setting of thumb dials. . . . . . .. . .. 030

Orifice used. . . . . . .. ... . . .202842

0.218 in. (5.54 mm)

Maximum engine rpm at

1500 psi (10 300 kPa) (103 bar). . _. . _. _. . 1950

Litho in U.S.A.
90 Sys tern Testing JD750 Crawler Bf.rlldozer
9035-16 Specifications and Special Tools, TM- 1136 (Aw- 791

HYDRAULIC SYSTEM (ANALYZER)

SPECIFICATIONS AND TORQUE VALUES-Continued

CIRCUITS
SPECIFICATION

BLADE
DOWN (POWER)

AUXILIARY LIFT

2000 + 175 - 0 PSI (13 800 + 1 200 - 0 kpa) (138 + 12 - 0 bar)

SYSTEM RELIEF VALVE
AT FAST IDLE WITH TEMPERATURE OF OIL BETWEEN 140 and 150°F (60 and 66'C)
P66090N

Fig. 16-Bulldozer Function Chart

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Specifications and Special Tools 9035-l 7

HYDRAULIC SYSTEM
SPECIAL TOOLS
Essential Tools
Tool Tool Number Use
D-l 5028NU Not illustrated - Universal pressure
test kit used to check pressure
readings at specific locations.

D-15017NU Hydra-Analyzer Flow Test Meter

used to check system flow, pres-
sure and temperature.

D-15013NU Hydraulic flow test fitting kit used to

‘I
make hydraulic connections.

m
Fig. 17-Pump Flow Meter

Convenience Tools

Tool Tool Number Use

D-01 08OAA Master Hydraulic System Analyzer
used when testing hydraulic sys-
tem.

D-O 1084AA Tachometer/Temperature Reader

used to measure engine rpm and
oil temperature.

D-01 088AA Construction Equipment Accessory

Kit fittings used to make hydraulic
connections.

l-Master Hydraulic System Analyzer

P-Tachometer/Temperature Reader

Fig. lb-Hydraulic System Analyzer

Litho in U.S.A.
 90 _Sv_stem Testing JD750 Crawler Bulldozer
9035-l 8 Specifications and Special Tools TM- 1136 (Apr- 79)

HYDROSTATIC SYSTEM
SPECIFICATIONS AND TORQUE VALUES

Transmission

1. Charge pressure in neutral . . . . . . 260 - 340 psi

(18 - 23 bar) (18 - 24 kg/cm*)
2. Charge pressure in stroke . . . . . . 200 - 240 psi
(14 - 17 bar) (14 - 17 kg/cm*)
3. System pressure
(forward and reverse) . . . . . . . 6100 - 6400 psi
(421 - 441 bar) (429 - 450 kg/cm*)
4. Charge pump inlet vacuum Max. 10 in. (254 mm)
Hg at 100°F (38°C)
and 2100 ? 10 rpm
5. Maximum case pressure. . . . . . . . . . . . . . . . . 50 psi
(3 bar) (4 kg/cm*) at
140 - 160°F (60 - 71°C)

Fig. 19-Left Transmission Test Ports

Transmission Control Valve

1. Pl overpressure relief
valve pressure . . . . . . . . . . . . . . . 280 - 340 psi
(19 - 23 bar) (20 - 24 kg/cm*) at
2100 -c 5 rpm and
140 - 160°F (60 - 71°C)

2. P2 pressure regulating
valve pressure . . . . . . . . . . . . . . . 160 - 200 psi
(11 - 14 bar) (11 - 14 kg/cm*)
at 2100 + 5 rpm and
140 _ 160°F (60 - 71°C)

Litho in U.S.A.
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 7s) Specifications and Special Tools 9035-19

HYDROSTATIC SYSTEM
SPECIFICATIONS AND TORQUE VALUES-Continued

Pl differential control pressure . . . . .50 r 1 psi

(3 ? 0.07 bar) (4 ? 0.07 kg/cm*)
at 2100 ? 5 rpm and
140 - 160°F (60 - 71°C)
and 60 t 1 psi
(4 -e 0.07 bar) (4 2 0.07 kg/cm2)
at 1000 2 5 rpm
and 140 - 160°F (60 - 71°C)
3. P3 differential control pressure . . . . .6 + 1 psi
(0.41 t 0.07 bar) (0.42 -c 0.07 kg/cm2)
at 2100 2 10 rpm and
140 - 160°F (60 - 71°C)
4. P4 differential control pressure* . . . . .80 & 10 psi
(6 4 0.7 bar) (6 2 0.7 kg/cm*) at

q
2010 to 2020 rpm and
140 - 160°F (60 - 71°C) ’ ’
5. P5 differential control pressure . . . .I24 2 2 psi
(9 + 0.14 bar) (9 -c 0.14 kg/cm*)
Fig. 20-Transmission Control Valve Test Ports at 2200 ? 10 rpm and
140 - 160°F (60 - 71°C)
6. P6 differential control pressure . . . .124 & 2 psi
(9 + 0.14 bar) (9 t 0.14 kg/cm*)
at 2200 + 10 rpm and
140 - 160°F (60 - 71°C)
7. P7 differential control pressure . . . ,124 I 2 psi
(9 r 0.14 bar) (9 2 0.14 kg/cm*)
at 2200 2 10 rpm
and 140 - 160°F (60 - 71°C)
8. P8 differential control pressure .124 2 2 psi
(9 t 0.14 bar) (9 t 0.14 kg/cm*)
at 2200 t 10 rpm
and 140 - 160°F (60 - 71°C)
9. P9 differential control pressure ... 100 psi
(7 bar) (7 kg/cm*)
in not less than 1 .O second
nor more than 2.0 seconds
at 140 - 160°F (60 - 71°C)

Oil Cooler Bypass Valve

Relief pressure setting .. . .... . 40 psi
(3 bar) (3 kg/cm2)
at 140 - 160°F (60 - 71°C)

*Optimum P4 differential control

pressure . . . . . . . . 80 psi (5.52 bar) (5.62 kg/crrf)

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90 System Testing JD750 Crawler Bulldozer
9035-20 SDecifications and SDecial Tools TM- 1136 (Apr- 79)

HYDROSTATIC SYSTEM
: SPECIAL TOOLS
Essential Tools
Tool Tool Number Use

D-01 082AA Hydrostatic analyzer used to record

system and control pressure data
for testing and adjusting hydrostatic
drive circuit.

D-01 080AA Master hydraulic system analyzer

used to recdrd system and control
pressure data for testing and ad-
justing hydrostatic drive circuit.

D-01 083AA Hydrostatic switching unit used with

hydrostatic analyzer for checking
dual path hydrostatic drive cir-
cuits

D-01 084AA Tachometer/temperature reader

used in conjunction with hydrostatic
analyzer to give engine rpm and
hydrostatic system temperature
reading.

D-01 087AA Master accessory kit contains fit-

tings, adapters, etc. required for
connecting hydrostatic analyzer to
l-Hydrostatic Analyzer 3-Hydrostatic Switching hydrostatic circuit.
2-Master Hydraulic Unit
System Analyzer 4-Tachometer/Temperature
Reader

fig. Pl-Hydraulic System Analyzer

Convenience Tools
” ,, JD-366 Track Restraint Bars
(4 used)

fig. 22-Track Restraint Bars

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 -
JD750 Crawler Bulldozer System Testing 90
TM- 1136 (Apr- 79) Specifications and Special Tools 9035-21

AIR CONDITIONING SYSTEM

SPECIFICATIONS AND TORQUE VALUES

Compressor belt tension . . . . . . . l/4 in. (6.35 mm)

with 15 Ibs. (67 N) (7 kg)
force

Operational Temperature Pressure Chart

Outside air temperature . . . . . . 80 - 110°F
(27 - 43°C)

Compressor discharge
pressure...........................175 - 300psi
(12 - 21 bar) (12 - 21 kg/cm2)
.-
Compressor suction
pressure. . . . . . . ..___.~. . . . . . . . .10 - 30 psi

q
(1 - 2 bar) (1 - 2 kg/cm*) , ,

Air outlet temperature . . . . . . . . . . . . . . 45 - 70°F

(7 - 21°C)

Evacuating system (sea level) 29 - 29.5 in. vacuum

(72 - 73 mbar)
30 minutes minimum

Capacity of system . . . . . . . . . .3-l 12 Ibs (1.6 kg)

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90 System Testing JD750 Crawler Bulldozer
9035-22 Specifications and Special Tools TM- 1136 (Apr- 79)

AIR CONDITIONING SYSTEM

SPECIAL TOOLS

Convenience Tools

Tool Tool No. Use

Manifold Pressure Gauge Set D-18019KDt Testing system pressures

Safety Goggles D-18020KDt Protecting eyes
Leak Detector D-05232ST Detecting refrigerant leaks
Air Conditioning Wrench D-18021 KDt Adjusting service valves
Pocket Thermometer D-18022KDt Measuring outlet air temperature
Refrigerant Can Dispensing Valve D-l 8023KDt Using pressurized refrigerant cans
Antiblowback Valve D-l 8024KDt Prevent system pressure
blowback into refrigerant can
Test Plate D-18032KDt Connect manifold pressure
gauge set to compressor
Portable Vacuum Pump D-l 8003KDt Evacuating system

tAir Conditioner Test Equipment Kit No. D-18018KD

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JD750 Crawler Bulldozer Sys tern Testing 90
TM- 1136 (Apr-79) Specifications and Special Tools 9035-23

/ I
MISCELLANEOUS COMPONENTS
SPECIFICATIONS AND TORQUE VALUES

1 - Track sag . . . . ....... 1 to l-1/2 in.

(25.4 to 38.1 mm)

Fig. 23-Track Sag

1 - Adjust shim pack to make dimensions (A) equal.

2 - Adjust shim pack to make dimensions (B) equal.

3 - Clearance between inner guide

wear strip and track frame
wear strip.. . . . . . . . . . . . .O.OO to 0.04 in.
(0.0 to 1.0 mm)

Fig. Pl-Front idler Guides

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90 Sys tern Testing JD750 Crawler Bulldozer
9035-24 Specifications and Special Tools TM- 1136 (Apr- 79)

Litho in U.S.A.