DOCUMENT RESUME

ED 246 299 CE 039 361

AUTHOR Batchelor, Leslie A.; Abercrombie, Richard, Ed.

TITLE Heavy Duty Mechanics Apprenticeship Training, Module
One. Volume I.
INSTITUTION British Columbia Dept. of Education, Victoria.
REPORT NO ISBN-0-7718-8234-3
PUB DATE [80]
NOTE 636p.; For volume II, see CE 039 362.
AVAILABLE FROM Publication Services Branch, Ministry of Education,
878 Viewfield Road, Victoria, BC V9A 4V1 (Set of two
volumes--$15.00).
PUB TYPE Guides - Classroom Use - Materials (For Learner)
(051)

EDRS PRICE MF03 Plus Postage. PC Not Available from EDRS.

DESCRIPTORS *Apprenticeships; *Auto Mechanics; Electricity;
Engines; *Equipment Maintenance; Equipment
Utilization; Foreign Countries; Hand Tools;
*Hydraulics; Inservice Education; Job Skills; Machine
Tools; Measurement; Measurement Equipment; Mechanical
Skills; *Mechanics (Process); On the Job Training;
Postsecondary Education; Safety; School Shops; *Trade
and Industrial Education
IDENTIFIERS Automotive Suspension Systems; Brakes (Automotive);
British Columbia; *Heavy Equipment Mechanics

ABSTRACT
This training manual, the first of two volumes,
comprises the first six blocks in a nine-block in-service training
course for apprentices working in heavy duty mechanics. Addressed in
i
the individual blocks included in this volume are the following
topics: shop equipment and practices; procedures for starting,
moving, and stopping equipment; the principles and theory of
hydraulics; brakes; power trains; and frames, suspensions, running
?vh-, and working attachments (bearings and seals; track machine
&nderzarriages; track machine final drives; track machine steering;
wheel machine Suspensions; tires, rims, and wheels; wheel machine
final drives; wheel machine steering and front suspension; and
working attachments). Each block contains 'a section on parts theory
that gives the purpose, topics, operations, and applications ,f the
parts and systems being discussed; a set of questions on parts
theory; a section on scheduled maintenance and, service repair; a set
of questions on service; and a list of validated tasks to be
completed during the course of daily on-thejoh routines. The manual
is illustrated with photographs and drawings. (MN)

..**********************************************************************
* Reproductions supplied by EDRS are the best that can be made *
* from the original document. *
***********************************************************************
 Heavy Duty Mechanics
Apprenticeship Training,
Moduie One
VOLUME I

0EARTAIEN7 Cl soucAnorr Province of British Columbia

NATIONAL INSTITUTE
s*IO EDUCATION
E0i0CATt3k1AL PESOLIKLe "PERMISSION TO REPRODUCE THIS
4FORMA NN MATERIAL IN MICROFICHE ONLY
CENTER IESIC,
This document
has been .eorodo HAS BEEN GRANTED BY
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INFORMATION CENTER pm.-

Developed by Program Research and Denloproent.

Ministry of Education
In Cooperation with the:
Apprenticeship Training Programs Branch.
Ministry of Labour
Canadian Cataloguing in Publication Data
main entry under title;
Heavy duty mechanics apprenticeship training.

Prepared for publication by LesliA A. Batchelor ;

Richard Abercrombie, editor.
ISBN 0-7718-823h-3

1. Machinery - Maintenance and repair - Handbooks,

manuals. etc. I. British Columbia. Ministry of
Education. Program Research and Development. II.
British Colambia. Apprenticeship Training Programs
Branch. III. itatchelor, Leslie A. IV. Abercrombie,
Richard.

This manual was prepared for Publication by.

Leslie A. Batchelor.
Heavy Duty Mechanics Instructor.
Cariboo College.
Richard Abercrombie. Editor.

3
 ACKNOWLEDGMENTS

We wish to thank the following members of the Heavy Duty Mechanics Trade
Advisory Committee to the Ministry of Labour who were instrumental in
initiating the writing of this manual:

Ken Brown. Coast Tractor and Equipment Ltd.

Art Latto. Kaiser Resources Ltd.
Doug LaVae. Finning Tractor and Equipment Co. Ltd.
Dennis Waunch. International Union of Operating Engineers
R. Thygesen Pulp. Paper and Woodworkers of Canada
Don Staples. B.C. rarest Products Ltd.
Jim Cameron. Utah Mines Ltd.
Dave Baston. Apprenticeship Counsellor. Ministry of Labour
Vic Amirault. Program Development Officer. Ministry of Labour

We wish to also extend our thanks to other members of the Heavy Duty
Mechanics Trade Advisory Council for the support they gave to this manual.

0 141"Sff if of ElIKOP012 P f Ov 47C0 Of BOO Cotomo,a Canada

No pan 0 this publication may be reproduced in any
form irnthaut permission in *ramp from me publisher

1:
4
 INDIODUCTION

This is an in-service training manual for ap likely .o be doing in your shop. Another set of
prentices working in heavy duty mechattios questions ft,11)ws the service section. The
shops who wish to complete tA9dulo One, blocks end wi h a list of practical tasks that
Heavy Duty Mechanics Apprenticeship should be done during daily work at your job.
Training in-service. it covers the same Your employer has a Task Check Chart, that
material that is taught in the 14 week training he will complete to vouch that you have done
program for Module One at the vocational all the tasks listed in the manual.
schools. Although you don't have an in-
structor to assist you like apprentices at Following is some advice on how to approach
school. you will receive assistance from your the ceurue:
employer and the journeyman you work with.
it is expected that the program will be
The manual is divided into nine blocks: (1) completed within a three month period;
Shop Equipment and Practi;es, (2) Starting. however, provision is made for up to a
Stopping. Moving Equipment. (3) Hydraulics, three month extension if required. Try
(4) Brake;_;. (5) Power Trains. (6) Frames. to space the blocks out over the time
Suspension. Running Gear and Working At- you set to do the course. There is a lot
tachwrits. (7) Engines. (8) Electricity. and (9) of material here. and if you leave it all
Winches. Hoists and Cables. The material in to the end. you won't get finished.
blocks 1. 2. 6 and 9 is dear. with in a fairly Monitoring of your progress in the
thorough manner as these subjects won't be co'irse is done by your employer and
covered again in your training courses. The by contact with the Apprenticeship
other blocks, blocks 3. 4. 5. 7 and 8. are intro- Branch. Since this is an individualized
ductions that give a basic grounding in their learning package. there is no one
subjects. The topics in these blocks will be standing over you telling you to do so
covered in greater detail in later courses. The much today and so much tomorrow.
main idea behind the depth that subjects are The onus is on you to keep a regular
studied in this manual is to try to relate progress through the course. And it
course material to the work you will actually won't be easy.
be doing in the shop at this level of your ap- Don't skip out a section thinking that
prenticeship. This is the reason. for example, you already know it. There probably
that detailed information is given on frames. will be material in it that you are un-
suspensions and running gear. whereas only certain of. And Desides. if you know
basic information is given on electricity: it is most of th(d material already you'll be
assumed the t you will be doing a lot of work able to go through it quickly.
on suspension and running gear. but little on
electrical systems. Blocks 1.2. 3, 4 and 5 should be done
first. The other blocks can be taken in
Each of the blocks is laid out in the following any order, although it's probably best
pattern: the block begins with a section on to take them in the order in which they
parts theory that gives the purpose, types. come.
operations (how they work) and applications
(where they are used) of the parts and The questions are straightforward;
systems be' ig discussed. A set of questions there are no trick ones. They can all be
follows the parts theory. the answers to which answered from a close study of the
are given at the end of the block. Next is a text. Try to do as many of the questions
section on service that is divided into Daily as you can, without going back to the
Routine Maintenan -e. Scheduled Main- text. If you can't get a question, then
tenance and Service Repair. Daily Routine open the text and seek the answer
Maintenance deals with watchful visual rather than turning to the answers. This
checks and adjustments; Scheduled Main- way you re-read the topic and get a
tenance with scheduled lubrication and more complete understanding of it than
checks; Service Repair with removal. if you just look up the answer.
disassembly, repair or replacement and in- The practical tasks should normally be
stallations. The Service Repair sections in the completed as you work on the material
blocks that are written at a basic level are in each blocks however, this may not be
limited to the types of repair that you are

5
SiliiIMEMEIMENIRM=MINMMI11

practical due to other work com-

mitments in the shop.
N.B. Some tasks t ay have already
been covered in your day to day
work.
Check with your employer to ensure
that an areas of practical training have
been covered.
When you complete this manual 2 44
the practical tasks you will be required
to write an Apprenticeship Branch
examination.
 TABLE OF CONTENTS

BLOCK 1 SHOP EQUIPMENT AND PRACTICES

The Heavy Duty Mechanics Trade 1.1
Service Literature. Parts Lists. and Reports 1.1
Service Manuals 1.1
Parts Books 1.4
Parts Lists 1.6
Service Report 1.8
Shop Safety 1.9
Personal Safety 1.13
Hand Tools 1.15
Hammers 1.15
Wrenches 1.16
Torque Wrenches 1.19
Pliers 1.21
Files 1.22
Vises 1.23
Hacksaws 1.24
Taps and Dies 1.25
Chisels 1.27
Punches 1.27
Twist Drills 1.29
Screwdrivers 1.30
Soldering Tools 1.32
Thread Restcrer Kit 1.33
Brushes and Scrapers F34
Snips 1:35
Reamers 1.36
Screw Extractors 1.36
Stud Puller 1.37
Wire Splicers 1.37
Pullers 1.37
Pipe and Tubing Tools 1.42
Questions - Hand Tools. Shop Safety. Service Literature 1.43
Air. Electric and Hydraulic Power Tools 1.47
Impact Wrenches 1.47
Bench Grinder 1.47
Portable Grinders 1.48
Hand Drills 1.48
Drill Press 1.49
Hydraulic Power Tools 1.50
Presses 1.50
Pullers 1.51
Steam Cleaners 1.52
Questions - Air. Electric and Hydraulic Power Tools 1.53
Measuring Tools 1.54
Calipers and Dividers 1.54
Feeler Gauges 1.54
Vernier Calipers 1.55
Micrometers 1.57
Telescoping Gauges and Small Hole Gauges 1.62
Dial Indicators 1.62
Questions - Measuring Tools 1.63
Fasteners 1.67
Bolts and Cap Screws... 1.67
Nuts 1.70
Removing Stubborn Nuts 1.72
Restoring Threads 1.73

7
 Washers 173
Cotter Pins 1'74
Lock Wires V75
Flat Metal Locks 1'75
Keys 1.76
Splines V76
Pins 1.77
Rivets 1'79
Questions Fasteners 111
Hoses, Pipes, Tubes. Fittings and Adapters 113
Hose 113
Hose Fittings 116
Good Practices when Installing Fittings 118
Pipes and Tubes 119
Pipe Fittings 1'89
Good Practices for Installing Pipes and Pipe Couplers 111
Tube Fittings 1'91
Good Practices when Installing Tubes and Tube Fittings 116
Questions Hoses, Pipes, Tubes, Fittings and Adapters 117
Lifting and Blocking 118
Types of Lifting Equipment 1:98
Hydraulic Hoists and Jacks 119
Chains 1101
Wire Rope Slings r 1102
Hooks 1105
Shackles 1106
Lifting Eyes 1.106
Spreader And Equalizer Beams 1.107
Blocking and Stands 1108
Lifting Procedures and Precautions 1109
Questions Lifting and Blocking 1111
Welding 1112
Cylinders Handling. Storage and Safety 1112
Hose and Connections 1113
Regulators 1i13
Oxygen and Acetylene Cylinders 1114
Oxygen and Acetylene Gases 1115
Welding Torches 1116
Set Up Oxyacetylene Equipment 1118
Oxyacetylene Flames 1122
Shutting Off Oxyacetylene Equipment 1123
Healing 1123
Flame-Cutting 1123
Cutting Torch Tips 1124
To Prevent Fires and Explosions 1126
Backfires and Flashbacks .1:127
Fusion Welding 1128
We Idfaults 1130
Braze Welding 1133
Questions Welding 1137
Answers Hand Tools. Shop Safety. Service Literature 1139
Answers Air, Electric and Hydraulic Power Tools 1140
Answers Measuring Tools 1141
Answers Fasteners 1.142
Answers Hoses, Pipes, Tubes. Fittings and Adapters 1143
Answers Lifting and Blocking 1144
Answers Welding 1145
Tasks Shop Equipment and Practices 1146

8
.1811301111M1111111111MINIIIMMIIIMIIIMMIMEM11184
BLOCK 2 STARTING, MOVING AND STOPPING EQUIPMENT
Starting, Moving and Stopping Equipment 21
Pre-Start Checks 21
Walk Around Inspection 2.4
Starting and Moving Equipment 2.6
Emergency Shut Down Procedures 2.6
Starting Procedures, Cold Starting Aids. and Stopping Procedures 2.7
Starting Procedures. Including Safe Use of Cold Starting Aids 2.7
Engine Oil and the Battery in Cold Starting 2.8
Detroit Diesel 2.9
Cummins Diesel 2.10
Caterpillar Diesel Engine 211
After Start Checks 212
Moving Vehicles 213
Safety Precautions with Articulated Steering 219
Common Causes of Injury in the Heavy Dui) Field 2:20
Machine Storage 2.22
Questions Starting. Moving and Stopping Equipment 214
Answers Starting. Moving and Stopping Equipment 226
Tasks Starting. Moving and Stopping Equipment 2.27

BLOCK 3 PRINCIPLES AND THEORY OF HYDRAULICS

Principles and Theory of Hydraulics 31
Basic Principles of Hydraulics 3.2
Pressure. Force and Area 3.4
Principles of Hydraulic Cylinders 3.6
Hydraulic Flow 3.7
Hydraulic Oil 3.8
Basic Circulating Hydraulic System 3.8
Hydraulic Components 310
Reservoirs 310
Filters 311
Pumps ;,.11
Hydraulic Motors 312
Control Valves 3.13
Actcumulators 3.14
Oil Coolers 316
Hydraulic Cylinders 316
Questions Hydraulic Theory 3.17
Daily-Routine and Schisduled Maintenance on Hydraulic Systems 319
Safety Practices on a Hydraulic System 319
Flushing Procedures 3.21
Questions Maintenance of Hydrau;ic Systems 3.23
Answers Hydraulic Theory 3.24
Answers Maintenance of Hydraulic Systems 3 26
Tasks Hydraulics 3.26

BLOCK 4 BRAKES
Brakes 4.1
Brake Operation 4.1
Basic Friction Theory Related to Brakes 41
Facts on Braking 4.2
Brake Capacity 4.2
Types of Brake Systems 4.3
 Service Brakes 1.3
Standard Hydraulic Brakes 4.4
F)undation Brake 4:5
Drum Brakes 4.5
Disc Brakes 4.7
Multi-Disc Brakes 4:7
Power-Assisted Hydraulic Brakes 4.7
Vacuum-Assisted Brakes 41.9
.Air-Over-Oit Brakes 4.10
Oil-Over-0:1 Brakes 4.10
Air Brakes 4.11
Emergency or Parking Brakes 4:13
Integral Parking Brake 4:13
Drive Shaft Parking Brakes 4.14
Spring Brakes 4.15
Brake Fluid 4.16
Questions - Brakes 4.17
Preveltive Maintenance and Adjustments on Brakes 4.18
Needing Hydraulic Brakes 4.18
Adjulting Hydraulic Brakes 4:19
Acjusting Air Brakes 4.22
Aclusting Parking Brakes 4.24
Questions - Brake Maintenance 4.26
Answers - Brakes 4.27
Answers - Brake Maintenance 4.28
Tasks - Brakes 4.29

BLOCK 5 POWER TRAMS

Power Trains 5.1
Basic Function of Power Trains 5.1
How a Power Train Works 5.2
How Power is Transmitted 5.4
Gears 5.6
Gear Ratio 5.7
Types of Gears 5.7
Backlash in Gears 5.9
Power Train Components 5.10
C'utches 5:10
Torque Converters 5.12
Standard Mechanical Transmissions 514
Power Shift Transmissions 5.17
Drive Lines 5 18
Drive Axles .. 5:19
Retarders 5.22
Grease and Oil 5.23
Grease 5.23
Gear Oils 5.24
Care of Lubricants 5.24
Good Practices in Handling. Dispensing and Storing Lubricants 5.24
Questions - Power Trains 5.26
Preventive Maintenance Service of Power Trains 5.27
Clutch Adjustment 5.27
Scheduled Maintenance on Power Trains 5:30
Lubrication Service Examples 5.30
Lubrication for On and Off-Highway Manual Transmissions 5.31
Lubrication and Maintenance Checks for a Crawler Dozer (Cat D6)

10
J
 With a Power Shift Transmission 5.33
Lubrication and Maintenance Checks on a Wheel Loader With a
Power Shift Transmission and Standard Drive Axles 5.35
Scheduled Maintenance on Retarders 5.38
Removing Axle Shafts 5.38
Questions - Power Train Maintenance 5.39
Answers - Power Trains 5.40
Answers - Power Train Maintenance 5'41
Tasks - Power Trains 5.42

BLOCK 6 FRAMES, SUSPENSION, RUNNING GEAR AND

WORKING ATTACHMENTS
BEARINGS AND SEALS
Purpose of Anti-Friction Bearings 61
Identifying Bearings When Ordering Replacements 6:2
Bearing Capacity 6.3
Radial and Axial Loading on Bearings 6.3
Six Common Types of Bearings 6.3
Lubrication of Anti-Friction Bearings 6.5
Preload on Anti-Friction Bearings 6.5
t
Removal and Installation of Bearings 6.5
Methods of Lubricating Anti-Friction Bearings 612
Bearing Adjustments 613
Bearing Terminologi 614
Questions - Bearings 6.15
Answers - Bearings 6.16
Purpose of Seals 6.17
Types of Seals 5.18
Dynamic Seals 6.18
Static Seals 6.23
Removing and Installing Seals 6:26
Questions - Seals 6.29
Answers - Seals 6:30
Tasks - Bearings and Seals 6.31

TRACK MACHINE UNDERCARRIAGE

Purpose of Track Machine Undercarriage 6.33
Crawler Loader and Crawler Dozer Undercarriages 6.33
Excavator. Shovel and Crane Undercarriages 6.36
Undercarriage Components 6.37
Track Frames 6.38
Recoil Mechanism and Hydraulic Track Adjuster 619
Front Idler 6.40
Sprockets 6.41
Drive Sprockets and Tumblers 6.43
Track Rollers 6.43
Carrier Rollers 6:45
Tracks 6.45
Track Chains 6'46
Track Shoes 6'48
Shovel and Crane Tracks 6'51
Shovel and Crane Swing Assembly 6:52
Undercarriage Guides and Guards 6.55
Questions - Track Machine Undercarriages 6.56

11
Undercarriage Maintenance and Repair 6.57
Maintenance and Service Life 6.57
Daily. Routine Maintenance Checks on Undercarriages 6.58
Track Tension: Dozers. Loaders. Excavators 6.61
Track Tension: Shovels. Cranes 6.64
Questions Undercarriage Daily. Routine Maintenance 6.66
Scheduled Maintenance 6.67
Undercarriage Wear 667
Measuring Undercarriage Wear 6.69
Alignment 6/9
Track Frame Alignment 6/9
idler Alignment 6.82
Questions Undercarriage Scheduled Maintenance 6.85
Service Repair on Track Machine Undercarriage 6.86
Removal and Inswilation of Tracks 6:86
Undercarriage Repairs 6.91
Installing Components To The Track Frame 6.96
Aligning the Individual Track Sides 6.97
Questions Undercarriage Service Repair 6.98
Answers Track Machine Undercarriages 6.99
Answers Track Undercarriage Daily. Routine Maintenance 6.100
Answers Undercarriage Scheduled Maintenance 6.101
Answers Undercarriage Service Repair 6.102
Tasks Track Machine Undercarriages 6.103

TRACK MACHINE FINAL DRIVES

Purpose of Track Final Drives 6.105
Types of Track Final Drives 6105
Single Reduction Final Drive 6.105
Double Reduction Final Drive 6.107
Planetary Final Drive 6.107
Excavator. Shovel. Crane. Final Drives 6.110
Questions Track Machine Final Drives 6.112
Final Drive Maintenance and Repair 6.113
Daily. Routine Maintenance 6.113
Scheduled Maintenance 6.113
Service Repair on Final Drives 6114
Questions Track Machine Final Drive Maintenance and Repair 6.119
Answers Track Machine Final Drives 6120
Answers Track Machine Final Drive Maintenance and Repair. 6121
Tasks Track Machine Final Drives 6.122

TRACK MACHINE STEERING

How Tracks Are Turned 6.123
Steering Clutches and Brakes 6.123
Multiple Disc Steering Clutches 6.123
Planetary Steering Clutch 6.125
Shovel and Crane Steering 6.127
Hydrostatic Steering 6128
Controls for Multi-Disc Planetary and Hydrostatic Steering 6134
Basic Lubrication and Cooling of Steering Systems 6:141
Questions Track Machine Steering 6.142
Maintenance. Troubleshooting and Repair on Single and
Multi-Disc and Planetary Steering 6.143
Daily. Routine Maintenance 6.143
Scheduled Maintenance on Steering Systems 6.145

12
Troubleshooting on Steering Systems 6147
Service Repair of Track Machine Steering 6150
Questions Crawler Steering Maintenance and Repair 6156
Answers Track Machine Steering 6157
Answers Crawler Steering Maintenance and Repair 61 55
Tasks Track Multi-Disc Steering System 6159

WHEEL MACHINE SUSPENSION

Purpose of Wheel Suspension 6161
Rigid Suspension 6161
Spring Suspension 6.166
Frames. 6166
Springs 6.168
Tandem Axle Suspension 6170
Equalizer Beam Leaf Spring Suspension (Hendrickson) 6:171
Four-Spring Tandem Suspension (Reyco) 6*172
Rockwell Leaf Spring Tandem Suspension 61 73
Mack Leaf Suspension 6:174
Rubber Suspension 6175
Hydro-Air Suspension 1.178
Air Suspension 6.181
Questions Wheel Machine Suspension 6184
Maintenance and Service Repair on Rigid and Spring Suspension 6185
Preventive Maintenance Loader. Grader & Skidder Rigid Suspension 6.185
Service Repair on Rigid Suspension 6186
Questions Rigio Suspension Maintenance and Repair 6190
Service of Truck Frames and Rear Suspension 6191
Daily. Routine Maintenance on Truck" Rear Suspension 6191
Scheduled Maintenance of Track Rear Suspension 6192
Service Repair of Truck Frames and Rear Suspension 6194
Repair on Non-Heat-Treated Frames 6194
Repair of Heat - Treated Frames 6195
Service Repair on Scing Suspension 6196
Axle or Bogie Misalignment 6198
Service Repair of Hydro-Air Suspension Cylinders 6.201
Questions Spring Suspension Maintenance and Repair 6.204
Answers Wheel Machine Suspension 6.205
Answers Rigid Suspension Maintenance and Repair 6.206
Answers Spring Suspension Maintenance and Repair 6:207
Tasks Wheel Machine Suspension 6.208

TIRES, RIMS AND WHEELS

Tires 6.209
Tire Construction 6.209
Tire Size and Load Range. 6.215
Rims and Wheels.. 6.216
Types of Heavy Duty Wheels and Rims . 6.217
Ballast 6.223
Tire Traction and Protection Devices 6.224
Questions Tires. Rims and Wheels. Ballast. Traction Devices 6.226
Maintenance and Service Repair on Tires. Rims and Wheels 6.227
Daily Routine Checks on Tires 6.227
Service Repair of Tires and Rims 6.229
Scheduled Maintenance on Tires 6.231
Mounting Wheels 6.233
Damage and Repair of Rims. Studs and Hubs 6.237

13
Service of Traction Devices 6.239
Questions - Tires. Rims. Wheels. Maintenance an Repair 6.241
Answers - Tires. Rims and Wheels, Ballast. Traction Devices 6 242
Answers - Tires. Rims. Wheels. Maintenance a.:d Repair 6.243
Tasks - Tires. Rims and Wheels. Traction Devices 6.244

WHEEL MACHINE FINAL DRIVES

Purpose of Wheel Final Drive 6.245
Single Reduction Spur Gear Final Drive 6.245
Sprocket and Chain Final Drives 6.246
Planetary Final Drives es 246
Maintenance and Service Repair of Wheel Machine Final Drives 6.250
Daily. Routine Maintenance Checks 6250
$nheduied Maintenance 6-21C
Service Repair of Wheal Final Drives 6.20
Questions - Wheel Final Drives 6.254
Answers - Wheel Final Drives 6-255
Tasks - Wheel Final Drives 6.256

WHEEL MACHINE STEERING AND FRONT SUSPENSION

How Wheels Turn 6.257
Manual Steering Systems 6.258
Manual Steering Gears 6.258
Front Suspension and Front Axles 6.261
Steering Axle 6.264
Steering Linkage 6.267
Power Steering 6.269
Power-Assist Steering 6.269
Full-Power Steering 6.270
Hydrostatic Steering 6.273
Steering Geometry 6.277
Wheel Balance and Unbalance 6.281
Questions - Wheel Vehicle Steering 6.283
Maintenance and Service Repair of Wheel Machine Steering and
Front Suspension 6.286
Daily Routine Maintenance 6.286
Scheduled Maintenance 6.286
Steering Lubricants 6.286
Removing Front Wheel Bearings 6.288
Installing Wheel Seals 6.290
Adjusting Bearings 6.290
Service Repair of Front Suspension and Steering 6.291
Steering Alignment 6.295
Wheel Balancing 6.299
Troubleshooting Steering 6.299
Articulated Steering Repair 6.300
Manual Steering Gear Repairs 6.300
Questions: Wheel Steering Maintenance and Repair 6.302
Answers - Wheel Vehicle Steering 6.304
Answers - Wheel Steering Maintenance and Repair 6.305
Tasks - Wheel Machine Steering and Front Suspension 6.306

14
WORKING ATTACHMENTS
Crawler Dozers 6.309
Crawler Loaders 6.315
Wheel Loaders 6.316
Hydraulic Excavators . 6'319
Crawler Shovels 6122
Hydraulic Cranes 6.323
Skidders 6.324
Graders . 6:325
Machine Balance and Counterweights 6.327
Canopies 6.329
Maintenance and Service Repair of Working Attachments ... 6:330
Daily. Routine Maintenance 6.330
Service Repair on Working Attachments 6132
Questions Working Attachments 6137
Answers Working Attachments 6138
Tasks Working Attachments 6:339

15
 BLOCK

Shop Equipment
and Practices

16
 SHOP EQUIPMENT AND PRACTICES 1:1

THE HEAVY DUTY MECHANICS TRADE SERVICE LITERATURE, PARTS usrs,

AND REPORTS
A heavy duty mechanic apprentice learns how
to maintain and repair such heavy duty 3 rvice Manuals
machines as tractors, dozers, !ogler%
graders. cranes, shoveia end trucks. The work W lh today's sophisticated equipment, service
ranges from simple daily maintenance checks manualr, are very important fools for
to complex rebuilding of major components. A mechanics. The mam.als usua=ty give a
goof mechanic has a basic knowledge of description of the part and its operation, then
mechanics *hat ne/arie can apply when con- give step by step procedures for dailV, routine
fronted with a problem. knows how to use ser- maintenance and scheduled maintenance, k
vice manilas. toots and equipiront to best ad- removal anc' installation of components, and
vai aage, Rm.!? .5 resOurceful when the need for dleassernbly. repair and ast)mbly. Tools
arises needed for the work are gene-ally Indicated.
Many manuals_ file° give cOduies to
There are many opportunities for qualified diagnose and troubleshoot malfunctions.
heavy duty mechar es. Some of the areas they Some people mink the, opening a service
can work in are; light and heavy duly con- manual is a sign of weakness showing a lack
struction. trucking. mining, logging. farming. of knowledge. Nothing con', be further from
public entities. the marine industry, and the truth. Smart mechanics, except when the
manufacturing. Heavy duty mechanics may are doing a job they are very familiar with,
work on a number of different types of always have the service manual nearby.
machines of they may specialize on one. Also.
they may specialize further by doing only one Mr..::t manufacturers issue service manuals for
type of repair, e.g., transmission work. There their equipment. Besides these, several com-
is room for advancement in the trade if panies publish general service n.unuals that
mechanics are so inclined; they can become contain information on man:* different types of
charge hands. foremen. superintendents or components and machines. Although these
service managers. Becoming an instructor in general mantials can be helpful. the manufac-
schools or for companies is an,.ther op- turer's manual is usually best. Remember.
portunity for experienced mechanic,. however. that aS much information as service
manue;s contain. they are not textbooks. They
UNION JURISDICTION do not give you the general theclf that lies
behind a part or component's design.
Some jobs require the skills of several trades operation, or servicing. Nor do they compare
at once: for example. a job may need a welder, similar types of components or parts used by
electrician. mechanic . millwright. operator, other manufacturers.
pipefitter. To protec' jobs in their individual
trades, unions have jurisdiction over their Manufacturers use different formts in their
parts cf the job. Crossing a trade line. e.g.. manuals. Before you use a spr.cific service
welding when a welder should be called in. manual. it is important to understand hc.:y its
can cause a lot of hard feelings. Most likely information is organized. If you are not
trade jur.adiction will be clearly explained to familiar with a mans".' read the introductory
you by your supervisor or union represen- section that explains new to use it. An exam-
tative. Follow jurisdiction rules. Remember, it ple from an introduction in a service manual
works both ways. you protect the jobs in other for a General Motor's truck is given below.
trades. and they in turn protect yours.

17
1:2 SHOP EQUIPMENT AND PRACTICES

IMPORTANT RIAD THIS PAGE used in many instances in the "Specifi-

cations" tabulations. These numbers are
MODELS COVERED provided primarily for unit identification or
truck model application eference, and should
This manual contains "On-The-Vehicle" main- be referred to when ordering parts. All detail
tenance and light repair information on Series service part numbers must be obtained from
70 through 9502 except M,N 9003-9502. Since the applicable Parts Book.
truck models with various combinations of
equipment are covered in this manual, the SPECIAL TOOLS
reader must necessarily refer to truck model
applications and methods of distinguishing Special tools and equipment are mentioned,
design differences in enoh manual section. and in many instances illustrated, throughout
the text. These tools are specially designed to
All standard equipment and the most com- accomplish certain operations efficiently and
monly used regular production iptions are in- readily. Such tools are mentioned in the text
cluded in this manual. Many special equip- by tool vendor's numbers.
ment and accessory items are available on
these trucks, however. these items are too Information regarding availability of these
numerous to permit their coverage in this tools can be obtained from your Zone Office,
manual. or directly from the Service Publications
Department. at Central Office.
MANUAL ARRANGEMENT
OPERATION
This manual is divided into major sections and
sub-sections in the sequence shown on the Operating instructions from the standpoint of
margin of the title page. A black tab bearing the drivbr are included in a booklet entitled
the major section number is placed on the "Owner's and Driver's Manual" which is
first page of each major section which in- placed in the cab of every new truck.
dexes with the tab on the title page. A section
contents is also included on the first page of ALPHABETICAL INDEX
each major section, when the major section is
divided into sub-sections. Important subjects, with manual page number
references, are alphabetically listed in the In-
PAGE AND ILLUSTRATION dex in the back of this manual.
NUMBERS
The manual pages are numbered con- Courtesy of Generel Motors Corporation
secutively within each section and sub-
section. Illustrations are numbered con-
secutively within each section, or within each
sub-section when the major section is so
divided.

METRIC CONVERSIONS
In the event metric conversions are required,
refer to conversion tables at the back of this
manual.

SPECIFICATIONS
Service data, fits. and tolerances are listed at
the end of each section or sub-section under
the heading "Specifications". In some cases
reference must also be made to these
"Specifications" for model application and
methods of distinguishing the various design
and construction differences.
Manufacturer's model or part numbers are

18
 SHOP EQUIPMENT AND PRACTICES 1:3

TABLE OF CONTENTS

1977 SEC. NAME

GENERAL INFORMATION

SERVICE 0 OA.
OB.
General Information
Lubrication

HEATING & AIR CONDITIONING

MANUAL 1 1A.
1B.
Heating
Air Conditioning

FRAME AND CAB

2A. Frame and Body Mounts
2B. Cab Maintenance
2 2C. Steel Conventional Cab
2E. Aluminum Tilt Cab
2G. Sheet Metal and Fiberglass
_
STF,ERING, SUSPENSION,
WHEELS AND TIRES
3A. Front End Alignment
3B. Steering
3 3C. Front Axle and Suspension
SERIES 70 3D.
3E.
Rear Suspension
Wheels and Tires
THRU 9502 REAR AXLE AND PROPELLER SUFI
4 4A. Rear Axle
4B. Propeller Shaft
EXCEPT M, N BRAKES

9003-9502 5 5B. Air drakes

50. Air Compressor and Governor

ENGINE
6A. Engine Mechanical
6B. Cooling
NOTE 6 6C. Fuel System
60. Engine Electrical
When reference is made in this 6E. Emission Controls
manual to a brand name. number. or 6F. Exhaust
specific tool, an equivalent product
may be used in place of the recom- TRANSMISSION & CLUTCH
mended item.
7A. Automatic Transmission
7 7B. Manual Transmission
7C. Clutch

8 CAB AND CHASSIS ELECTRICAL

SPECIAL TOOLS
Courtesy of General Mows Corporation INDEX

19-
 r.

1:4 SHOP EQUIPMENT AND PRACTICES

Parts Books Parts books. like service manuals. have in.

troductory sections explaining how to use the
Besides a service manual. heavy duty equip- book. A typical example from a Case Parts
ment has a parts book. Parts books illustrate book is shown below.
components in exploded-view diagrams
(Figure 1-1). in the diagram the parts are
given a reference number and the reference
key gives the part number, a description of the
part. and the quantity needed.

CLARK
L 1PM MT

TS - '7117

PROP SHAFTS - DOUBLE

Item Part No. Qty. Description
A 1900059 1 Prop shaft. front axle input
B 944862 2 Spider and bearing ass'y. (1nel. items 1.6. 8)
C 940093 1 Slip yoke ass'y. (Ina items 11 & 12)
1 N.S.S. 2 Spider (See item B)
2 N.S.S. 8 Seal, dust (See item B)
3 N.S.S. 8 Bearing (See item B)
4 N.S.S. 248 Roller (See item Et)
5 8 Seal and retainer (See item El)
6 10H-35 2 Fitting, grease
7 940089 16 Bolt
8 N.S.S. 4 Wire. weld (See item El)
9 1990114 1 Tube assembly
10 80-06 16 Nut
t1 N.S.S. 1 Slip yoke (Se item C)
12 10H-25 1 Fitting. grea.1
13 940091 2 Washer. retainer
14 940092 Washer. felt
15 940090 1 Retainer
Courtesy of Clark Equipment Company
 SHOP EQUIPMENT AND PRACTICES 1:5

GENERAL INFORMATION ORDERS

INDEXES Orders should plainly specify correct part

number, full description, quantity required,
This Parts Catalog is arranged for easy iden- machine model and engine model. machine
tification of Genuine CASE Service Parts. An and engine serial numbers, method of ship-
alphabetical index is provided at the front of ment and shipping address.
this Catalog to locate the major groups or
assemblies. A numerical index at the rear of CHANGES
the Catalog gives the part numbers and the
pages on which they are described. When changes to the machine make it
necessary, revised pages for this book will be
ILLUSTRATIONS issued. The revised pages will be issued with
the same page number as those they replace
All parts are illustrated in "Exploded Views" and the "Issue" number and date will be ad-
which show the individual parts in their nor- vanced.
mal relationship to each other. Reference
numbers are used in the illustrations. These It is imperative that revised Parts Book pages
numbers correspond to those in the be inserted into their respective Parts Books
"Reference Number" column and are followed as soon as received. Failure to do so will lead
by the part number. description and quantity to confusion and 'defeat the purpose of the
required. book.

INDENTED DESCRIPTION
Indented parts in the description list are a part of the preceding assembly or sub-assembly. The
quantity shown in the "Number Required" column is the number of parts used on a machine except
where parts are indented in descriptive list. In this case the quantity shown is the number required
for the preceding assembly or sub-assembly.

REF. PART NO. DESCRIPTION REQ'D.

A 55159 CYLINDER ASSY. - rear steering 1
28 A 56208 SOCKET ASSY. - rear cylinder I
29 A 55956 PLUG - adjusting, socket assy. 1

30 A 55957 SEAT - socket ball 2

31 A 56210 SPRING - socket
-,
32 A 56209 SEAT - socket spring 1

33 G 45175 CLAMP ASSY. - socket assy 1

34 16. 836 HHCS - 1/2" - 20 NF x 2-1/4" 1

35 132 104 PIN - cotter. 3/16" dia. x 3" 1

TERMS "RIGHT HAND" AND "LEFT HAND"

"Right Hand" and "Left Hand" sides of the crawler are determined by sitting in the operator's seat
facing the direction of forward travel. "Right Hand" and "Left Hand" sides of the backhoe are deter-
mined by sitting in the operator's seat facing the backhoe.

0670160
Issued March, MN

Couriesy of J.I. Case

z1
1:6 SHOP EQUIPMENT AND PRACTICES

Parts Lists (b) Parts book is not available, but the

part is stamped: record the numbOr
You will be expected to write parts lists for the stamped on the part. mentioning that
machinery you work on. Some general points this is where the number is taken
about parts lists are: from (See the example for (c) ).
1. Always include with any parts list the (c) No parts book and no number stam-
make, model. and serial number oi the ped on the part: parts for which you
machine. This is the most important piece have no numbers must be described
of identification on heavy duty equipment. as shown below:
Also. when ordering parts, for example for
an engine or transmission. include their Clarke Ranger Skidder Series 600
serial numbers as well. Location of serial Serial Number C-9046-240
numbers on a Case crawler tractor are
shown in Figure 1-2. Rear wheel planetary final drive
and hub
2. Name the component that the parts come
from and. as mentioned above, the aerial Parts Required:
number of the component if it has one. 1 only hub inner oil seal
3. When referring to a part or component I only hub inner bearing cone
write the name that the manufacturer uses (number on bearing) 799408
in the service manual or parts book, rather 1 only hub inner bearing cup (num-
than the name you personally may use for ber . l.-. -ring) 658985
it.
1 only nu -% outer Gaming cone

4. When listing the parts. keep the related (number on bearing) 672181
items together, i.e., don't give a bearing, 1 only hub outer bearing cop
then a gear, then a gasket and back to (number on bearing) 672182
another bearing. This makes the list hard
for a parts person to follow, and increases 1 only axle sna4t (left side)
the chances of missing a part. 1 only sun gear
5. State the quantity of each part required. 1 only internal gear
3 only planet pinion gears
6. When parts are received, check im-
mediately for quantity, correctness and 3 only planet pinion gear shafts
condition of parts. Advise the distributor 6 only planet pinion thrust washers
of any error, and make claims for any ship-
ping damages immediately with the
carrier.
7. There are three situations you can be
faced with when ordering parts:
(a) Parts book is available: this is fairly
straight forward as you lust list the
part numbers from the parts book as
in the example below:
Case Crawler Loader: Model 1150,
Serial #7108999. Parts for a Track
Roller:
1 only #36406 Shaft
2 only #36043 Bushing
2 only #35267 Seals
2 only #30116 Bearing cones
2 only #55807 Bearing cups
4 only #31329 Shims
1 only #36465 Hub double
flange

22
 SHOP EQUIPMENT AND PRACTICES 1:7

MODEL 1150 INDUSTRIAL CRAWLER TRACTOR

SERIAL NUMBER LOCATIONS

CRAWLER SERIAL AND

MODEL NUMBERS

ENGINE
SERIAL NUMBER

i.'"iEEcill;Ns,
1,3Mli TRANSMISSION SERIAL NUMBER

Counesy of J.1. Case

23
1:8 SHOP EQUIPMENT AND PRACTICES

Service Report
A service report should be short and concise.
A service report written before a repair is
made should contain:
1. What is to be worked on, and what is
wrong with it.
2. List the parts needed.
3. Statement to the effect that with the parts
listed the component can be rebuilt.
A service report written after repair is done
should:
1. List the parts used.
2. Briefly state what work was done.
An example of a service report satement for
the Clarke Skidder mentioned under the sec-
tion, Parts List, is given below (note that the
lists of parts would be included in the report,
in addition to the make. model and serial num-
ber of the machine):
"When the left rear final drive was
disassembled and inspected, the parts
listed were found to be worn or
damaged to the point of needing
replacement.
The spindle. hub. cover and wheel
assembly are all in good condition. In
my opinion it is economical to rebuild
this final drive."
Although service reports are discussed here,
it should be pointed out that the apprentice or
for that matter iourneyperson, in many cases,
will be given a work order and will not have a
say in what work is to be done. However,
when carrying out the work order, always
bring to the attention of your supervisor other
work that you find needs doing. Disregarding
it and following only the work order does not
make a responsible mechanic.

24
 SHOP EQUIPMENT AND PRACTICES 1:9

SHOP SAFETY
Most accidents don't just happen: they are
caused by carelessness. Always be con-
cerned with your own safety and with that of
others around you. The following cautions and
illustrations (courtesy of Mack Truck of
Canada Limited) show how ignoring common
safety rules can cause injury. even death.

GENERAL SAFETY PRACTICES IN

THE SHOP
CARBON MONOXIDE THE QUIET KILLER! 1. Do not run engines in enclosed areas
without adequate ventilation (Figure 1-3).
2. When checking the coolant, turn the
pressure cap slightly to release pressure
before removing the cap.
3. When raising a vehicle, chock the wheels,
and use a jack of sufficient capacity. Do
not extend the jack beyond its see limits.
Be sure the vehicle's handbrake is set
(Figure 1-3).
4. When workrtg under a vehicle, use axle
stands or rigid jacks, after raising the
vehicle to working height. Wear goggles
whenever needed; a drop of high-
detergent oil or other fluid could cause
the loss of your sight.
5. Knew what to expect from a part before
(1, assembling it. A hidden spring-loaded
bail dr shaft, can be a lethal weapon,
maybe not to you, but to someone else in
the near vicinity (Figure 1-3).
(1-3)
Counesy of Mack Truck of Canada Limited 6. Always awl off a machine before at-
tempting repairs, cleaning, adjusting.

7. Jtay out from under a suspended load

Figure '14).
8. Open doors slowly otherwise, you could
seriously injure someone (Figure 1-5).

(1.4)
Courtesy of Mack Truck of Canada Li Gated

(1-5)
Courtesy of Mack Truck of Canada Limited

25
1:10 SHOP EQUIPMENT AND PRACTICES

9. Watch for other floor traffic when moving 13. Keep jack handles up where they won't
material, especially at blind openings. be tripped over
10. Do not use carbon tetrachloride for 14. Stand creepers up when not in use.
cleaning. This fluid can cause serious in-
ternal injury, even death, if its fumes are 15. Keep work areas as tidy as possible.
inhaled (Figure 1-6). Cluttered surroundings can cause ac-
cidents.

11!=
4 1.. FIRE PREVENTION PRACTICES
Carelessness is the major cause 4:4 fire and
explosion in repair shops. Fire prevention
practices are listed below.
Airtzkilt
11181
1. Keep all inflammable fluids and materials
in their proper containers.
2. Heed No Smoking signs. They are there
for a purpose (Figure 1-8).

(1-6)
COUtteSY of Mack Truck of Canada Limited

11. Take precautions with compressed air

and gases:
Do not use air pressure for cleaning your
clothes or body. Serious injury to your-
self and others who are in the jet stream
may result (Figure 1-7).

(1-8)
Courtesy of Mack Truck of
Canada Limited

3. When discarding a cigarette, don't flip it:

make sure it is out. Use an ashtray or
container.
4. Keep fire doors clear: don't block them.
5. Keep fire fighting equipment in good
operating condition:
(1-7)
Courtesy of Mack Truck of Canada Limited Test fire hoses at regular intervals.
Extinguisher pressure should also be
never horse play with an air hose checked at regular intervals, Many
know the procedure for tapping a new modern extinguishers have a pressure
tank of any compressed gas before at- gauge that tells when they need
tempting the job recharging.
use a spray mask when spray pain- Refill extinguishers immediately after
ting. they have been used.
12. Clean up spills immediately. Knees and
backs have been thrown out when
people have stepped unexpectingly on
spilled fluid and slipped.

26
 SHOP EQUIPMENT AND PRACTICES 1:11

6. Watch where you point a lighted torch. 11. Gasoline is very volatile; its vapors can
You could injure someone (Figure 1-9), be set off by a spark. When working on
or light the place on fire. or near a fuel system, be very careful not
to do anything that would cause a spark.
12. Clean with non-inflammable solvents.
which are non-toxic and of high flash
point (100°F. or more). Do not use
questionable cleaning fluids in the
vicinity of open flames (such as welding
operations) or high heat sources.
Petroleum-based solvent is most com-
monly used in the trade for washing
parts, although diesel fuel is also used
for this purpose. Hot and cold caustics
(1-9) are also used for washing in some shops;
Courtesy of Mack Truck of they must be used with caution. If your
Canada Limited shop has a caustic wash tank obtain in-
7. Do not overload any one circuit with structions for its proper use.
plugs. Octopus connections (Figure 1-10)
are dangerous
IN CASE OF FIRE
wires have been divided into four main
cAsses: A, 13, C and D. The extinguishers
used to fight these fires are similarly classed
as an A, B, C or 0 Extinguisher.

Class "A" Fires occur in ordinary com-

bustibles such as wood, paper and textiles.
They are best extinguished by cooling below
the burning point with water or an ex-
tinguisher which has "A" on its lable.

Class "B" Fires occur in gasoline, oils

(1-10) and other petroleum products. Extinguish
DANGEROUS OCTOPUS CONNECTIONS such fires by smothering (i.e., depriving them
Courtesy of Mack Truck of of oxygen). Smothering can be accomplished
Canada Limited by using a "B" extinguisher, a wet blanket,
sand, CO2 (carbon dioxide) or in some cases,
8. When using an extension light under a a lid covering.
vehicle, protect the lamp from breaking
with a lamp guard. Lamps breaking near Class "C" Fires occur in live electrical ap-
accumulated oil or fuel have caused pliances and equipment. To put out an elec-
many fires. trical fire a non-conductor type of ex-
9. Keep a fire extinguisher handy when tinguishing agent is used. DISCONNECT the
welding. One small hot spark from a power supply before applying any ex-
siding torch can set off a major fire. tinguishing agent. Use an extinguisher
labelled "C". Note that often when the elec-
10. Good housekeeping is important in tricity is disconnected, a class "C" fire of ter
preventing fires. Keep the floor clean and reverts to a Class "A" or "B" fire.
clean up spilled combustible fluids such
as gasoline and oil immediately. Oily Class "0" Ares occur in certain com-
rags can ignite spontaneously: keep bustible metals. To fight these high intensity
them in a closed metal container, or bet- fires use a dry chemical "D" extinguisher.
ter still, dispose of them. Note that "0" fires are not likely to occur in
repair shops

t_.'t
1'. *....
27
1:12 SHOP EQUIPMENT AND PRACTICES

Locate the fire extinguishers in your shop. All fire occurs. you won't have time to waste
extinguishers have directions for use printed studying directions how to use the ex-
on the cannister. and include the letters tinguisher. The type of extinguishers you are
referring to the type of fire they can be used likely to find in a mechanical shop are
on. Study these directions beforehand so that illustrated in Figure 1-11.
you will be prepared for an emergency. It a
Type Contents Kinds of Fire How to :art Discharge

CARBON DIOXIDE CLASS B

Liquid (oil. gasoline.

Carbon Dioxide paint. grease) Puff pin 6 to 8 feet
under and
pressure. open valve about 42 sec.

(15-lb. size)

Type Contents Kinds of Fire How to Start Discharge

DRY CHEMICAL CLASS B

Bicarbonate of Three types:
soda with other These
dry chemicals extinguishers Pull pin
and cartridge of also have or collar, then
carbon dioxide some effect on 1) Open valve About 14 feet
gas CLASS A Or
FIRES 2) Press lever 22 to 25 sec.
(wood, paper. Or
textiles) 3) Turn over (30-1b. size)
and bump
then
squeeze
nozzle.
Contents Kinds of Pre How to Start Discharge

CLASS A
and for
Solution of CLASS B 21/2 gal.
aluminum size
sulfate and (off,
bicarbonate gasoline. Turn over 30 to 42 feet
of soda grease.
paint) 50 to 55 sec.

Courtesy of Mack Truck at

(1-11) ARE EXTINGUISHERS
Canada Limited

28
 SHOP EQUIPMENT AND PRACTICES 1:13

PERSONAL SAFETY 5. Operating a steam cleaner or dipping

parts in a cleaner.
Eyes
The Workers' Compensation Board, states
that properly fitting goggles (Figure 1-12).
face shields or other eye protective equip-
ment. appropriate to the work being done.
must be worn when performing any work in
which there is a hazard of eye injury (Figure 1-
13). Remember there are no second chances
with eyes: sight cannot be restored. Note that
there are 14 companies in North America
making glass eyes.

(1-14)
Courtesy of Mack Truck of
Canada Limited

Seek
1. Don't overestimate your strength. Many
back strains have been caused by people
lifting something that was too heavy for
them. Get help with heavy objects. or use
a lifting device.
(1-12)
Courtesy of Mack Truck of 2. Lift from a squatting position with the
Canada Limited back straight (Figure 1-15). Never reach
and lift.
3. Push a heavy object: don't pull it.

(1-13)
Courtesy of Mack Truck of
Canada Limited

Use a face shield or goggles when:

1. Grinding (Figure 1-14).
2. Hammering on hardened surfaces with a
ball peen hammer.
3. Electric welding (shield), acetylene
(goggles). (1-15)
4. Chipping with a hammer and chisel. Also.
you should put up some type of screen, to
protect others nearby from flying bits.

29
1:14 SHOP EQUIPMENT AND PRACTICES

Hands
Your hands are the most important tools you
have. Protect them. Remember it's hard to
count to ten on your hands when some of the
digits are missing (Figure 1-16).

(1.18)
Courtesy of Mack Truck of
Canada Limited

7. One of the best ways to protect your hands

is to use the proper tool for the job. Being
too lazy or impatient to get the right tool is
(1.16) a good way to smash up your hands.
Courtesy of Mack Truck of
Canada Limited 8. Never have a loose sleeve, tie, or shirttail
when operating a machine or working
Look after your hands: around a moving machine. Your hand or
1. Use gloves on jobs that require them. body could get drawn into the machine
with some pretty horrible results.
2. Use the guards provided on all machinery.
Feet
3. Take proper care of nicks, cuts, and scrat-
ches: blood poisoning can result from the The Workers' Compensation Board, states
slightest scratch. Treat cuts with first aid that safety-toed shoes must be worn in any oc-
(Figure 1.17). It's better to be sure today cupation where there is a danger of injury to
than hospitalized tomorrow. the toes. In accordance with this law, heavy
duty mechanics should wear safety boots.
4. Sweep up broken gless: don't try to pick
up the pieces with your hands. Head
5. Wash hands thoroughly. Stop skin trouble The Workers' Compensation Board, states
before it starts. that a hard hat must be worn in work areas
6. Never use a file or rasp without a handle where there is a potential hazard to the head
(Figure 1.18). from falling, flying or thrown objects or from
other harmful contacts. Many companies that
employ heavy duty mechanics now specify
that hard hats must be worn. Signs such as
Hard Hat Area are posted, and everyone must
wear a hard hat in that area. In most mills,
manufacturing plants, mines, logging areas,
and construction camps this is usually the
rule.

Ears
Hearing is as important as sight. It's as com-
mon nowadays to see sound muffs being worn
as it is hard hats. When working around
(1.17) machinery, noise levels can reach a level that
Courtesy 01 Mack Truck of
causes shortterm deafness. Continued ex-
Canada Limed posure to these levels can cause long term
deafness. Always wear ear protection when
working in areas of high noise levels.

30
 SHOP EQUIPMENT AND PRACTICES 1:15

HAND TOOLS
This section is intended as a basic in-
troduction to hand tools. For more detailed in-
formation. there are several good tool books
on the market. One of these is Peterson's
Tool Book No. 1, Basic Automotive Tools and
How to Use Them.

HAMMERS
Bail Peen Hammers (Figure 1-19): are
frequently used by shop servicemen. The flat
face is for hammering and the ball part is for
rounding off rivets and similar jobs. They are
available in various sizes rated according to
their weight.

Solt Hammers (Figure 1-20): are used in place

of steel hammers to protect machined sur-
faces or fragile parts. These hammers are
commonly made of lead. rawhide. plastic,
brass nr rubber.

Correct Use
1. The proper grip and striking angle of a
hammer are illustrated in Figure 1-21.
(1.20) SOFT HAMMERS
2. If the wedge in the hammer handle starts
Courtesy of John Deere Ltd.
to come out. drive it in again to tighten the
handle. If the wedge is lost, replace it
before using the hammer. Never work with
a hammer having a loose head.
3. Never use a steel hammer on a machined
surface: use a soft hammer.
BALL PEEN

(1-19)
BALL PEEN HAMMER
'FACE
X 2268 Courtesy of John Deere Ltd.

WRONG RIGHT
X 2.2$6

(1-21) CORRECT USE OF A HAMMER

Courtesy of John Deere Ltd.

31
4
1:16 SHOP EQUIPMENT AND PRACTICES

WRENCHES
Common wrenches are illustrated in Figure 1 -22.

STRIKING
WRENCH
OPEN END
WRENCH
COMBINATION
WRENCH
SPANNER
WRENCH

BOX
WRENCH
12-POINT
SOCKET
ADJUSTABLE TUBING
WRENCH WRENCH

SOCKET WRENCH
WITH RATCHET TORQUE WRENCH

(1-22) Common Wrenches For Bolts, Cap Screws, and Nuts

Courtesy of John Deere Lid.

Open-End Wrenches: have openings at either Adjustable Open-End Wrenches: have a

end of close but different sizes. The openings sliding jaw that is moved by an adjusting
are offset so that the wrenches can be flopped screw. Adjustable wrenches should mainly be
to give them more swing in cramped spots used when an odd sized nut or bolt is en-
(Figure 1-23). Note: never hammer on a stand- countered; otherwise an open-end wrench
ard wrench. Hammer only on a striking should be used. These wrenches aren't in-
wrench. Also don't use a bar or pipe to in- tended for hard service: treat them with care.
crease leverage on a wrench. Use a pipe only When using an adjustable wrench:
when an extension is needed because the nut
is hard to reach. 1. Always place the adjustable wrench on
the nut so that the pulling force is applied
to the stationary jaw side of the wrench
(Figure 1-24). This side can withstand
much greater force.
2. After placing the wrench on the nut,
tighten the adjusting screw so that the
wrench fits the nut snugly (Figure 1- 25).1f
the jaws are loose, they will round off the
nut.
3. Keep the wrench clean. Wash it oc-
casionally in cleaning solvent and apply a
light oil to the adjusting screw and slide.

(1-23) LOOSEN NUTS IN CROWDED PLACES

BY "FLOPPING" THE WRENCH
Courtesy of John Deere Ltd.

32
 SHOP EQUIPMENT AND PRACTICES 1:17

Special open-end and box wrenches come in

many different shapes and thicknesses
(Figure 1-27) for Jobs where nuts or bolts are
difficult to remove with ordinary wrenches.

(1-27) VARIATIONS OF BOX AND

X COMBINATION WRENCHES
?.:ourtesY of John Deere Ltd.
(1-24) Courtesy of John Deere Ltd.
Tubing Wrench: has an opening that fits over
hydraulic tubing. Tubing wrenches can only
be pulled in one direction; pulling in the other
direction, allows the Jaw to ride over the nut.
Tubing wrenches are available in six and
twelve points.
WRONG
Don't Pull On An
Adjustable Wrench
Until It Has Been
Tightened On The Nut
X 2281 (1-25)
Courtesy of John Deere Ltd. (1-28) TUBING WRENCH

Box Wrenches: both six and twelve point box Courtesy of John Deere LW,
wrenches (Figure 1-26) are available, but
twelve point are most common. Box wrenches Spanner Wrenches: are usually special toots
are sometimes referred to as 12-point wren- supplied with a machine. Some types of span-
ches. Because of their 12-points, box wren- ners are illustrated in Figure 1-29.
ches can turn with a minimum swing of 15
degrees compared with 30 degrees or 60
degrees for an open-end wrench.
Box wrenches won't slip off a nut since they
completely surround the nut. Combination box HOOK TYPE WRENCH
and open-end wrenches can speed up nut and
bolt installations. The box end is used to
break loose or snug down the nut, while the
open-end is used for greater speed for the rest
of the turning. These combination wrenches
are the most popular hand wrenches

r
COMBINATION OX AND OPEN-END WOO

(1-29) VARIATIONS OF SPANNER WRENCHES

Courtesy of John Deere Ltd.

I30X WRENCH
X 2E82
(1-26) BOX WRENCHES
Courtesy of John Deere Ltd,

33
1:18 SHOP EQUIPMENT AND PRACTICES

SOCKET WRENCHES
Modern socket wrenches have done more to
make a mechanic's job easier and faster than
any other tool. A full socket wrench set con-
tains sockets as well as various accessories
that allow the sockets to be pJt to best ad-
vantage.
) SINGLE HEX

Several types of sockets are available (Figure

1-30): single-hex sockets have 6-points:
double-hex sockets have 12-points; double DOUBLE HEX
square sockets have 8-points (for use on
square nuts). Extra deep sockets (Figure 1-31)
are made to remove spark plugs or nuts that
are a long way down on the bolts, such as U-
bolts. Each socket has a square hole in its top DOUBLE SQUARE
(Figure 1.30) to accept any one of a variety of
drive units. The square lug of the drive unit
comes in standard sizes of 1/4, 3/8, 1/2 and (1-30) TYPE OF SOCKETS
3/4 inch. The sizes most often used are 3/8 Courtesy of John Deere Ltd.
and 1/2 inch. Heavy duty 1 inch and 1-1/2 in-
ches are also made.
Socket wrench accessories (Figure 1-32) are
described below:
1. The speed handle is used for quickly in-
stalling or removing loose nuts that spin
freely. However, it does not allow enough
twisting force for final tightening.
2. The ratchet allows a nut to be removed
without lifting the socket off the bolt. Rat-
chets can be set so that they will pull in
both tightening and loosening directions. (1 -31)
Courtesy of John Deere Ltd.
3. A universal joint is used to work on nuts in
places where a straight wrench won't SPEED
reach. With a universal joint the wrench HANDLE
handle can be worked at an angle with the
socket.
4. A sliding "1" handle and extension can be
used where there isn't space to get the SLIDING
HANDLE
"r
ratchet handle in.
RATCHET
5. A torque wrench is another socket set ac- HANDLE
cessory. Torque wrenches are discussed EXTENSION
separately.
6. Adapters are available that accommodate UNIVERSAL
a ratchet to different size sockets (1/4, 3/8. JOINT
1/2, 3/4 inch).
7. Flex handles are used for the hard pulling
when disassembling and reassembling
components. Generally, flex handles are SOCKET
about twice the length of the ratchet
handle. (1-32) SOCKET SET ACCESSORIES
e.ro...... .0.16...,, SW* ........1............. ..lak FLEX
HANDLE
(1-32)

34
 SHOP EQUIPMENT AND PRACTICES 1:19

Adapters Multipliers
Adapters are used to change the wrench or Multipliers (Figure 1-34) are socket wrench at-
socket drive size up or down one size. For tachments that give a mechanical advantage.
example, if you have a 1-inch drive flex handle A multiplier consists of a handle, a small
and want to use a socket for a 3/4 drive set, planetary housing and male and female
use a 1-inch to 3/4 inch adapter (Figure 1 -33), square socket adapters. To use a multiplier.
Conversely. if you want to use a 1 inch drive install a flex handle or ratchet into the female
socket on a 3/4 inch drive flex handle, use a adapter and a socket onto the male adapter.
3/4 inch to 1 inch adapter. bold the handle of the multiplier with or.e
hand, and turn the flex handle or ratchet with
/....._,.....r....Z....%
1" the other. The socket is turned at a reduction
...1.1. FEMALE /'44).- , 4,6.3/4" thus multiplying the force applied to the
FEMALE sockets. Multipliers are available in 3/4 inch
and 1 inch drive sizes with a torque
multiplication of 4 : 1.
Cj--3/4" MALE -4- -V' MALE
FEMALE
SOCKET ADAPTER
(1-33) ADAPTERS
HANDLE

4-PLANETARY
HOUSING

(1-34) MULTIPLIER MALE

SOCKET ADAPTER

TORQUE WRENCHES
On modern machinery, torquing bolts is an im
portant procedure. Uneven torquing can
cause warping, leaks, cracks, and stressed
areas. Under and over torquing also causes
problems. Thus the need for torque wrenches.
Torque wrenches (Figure 1-35), like other
wrenches, tighten or apply torque to a nut, but
there is a difference. With ordinary wrenches
you rely on touch or feel to tell if a nut is tight.
whereas with a torque wrench a scale gives
exactly how much torque has been applied to
the nut. Torque wrenches take the guesswork
out of tightening nuts. You look up in the ser-
vice manual what torque should be applied,
then turn the torque wrench until the scale
reaches the recommended value. Most torque (1-36) TOROUE WRENCH
wrenches have a signalling device: the
desired torque is set on an indicator and when
that torque is reached the wrench gives a
signal. There are a number of good torque
wrenches on the market, and it's a matter of Courtesy of Owatonna Tool Company
personal preference which to buy,

35
I
1:20 SHOP EQUIPMENT AND PRACTICES

Torque 3. Take the torque reading while the wrench

is moving.
Note that the recommended torques in service
manuals are calculated according to this law. 4. Handle torque wrenches very carefully. If
For a bolt to stay tightened. it must be the wrench is dropped check it for ac-
tightened enough so that the load in the bolt curacy before using it again. Use the
is greater than the loads which the bolt must following method:
absorb during operation.
(a) Hang the torque wrench on a fixed
Torque is simply the lever principle of force nut as shown in Figure 1-37.
being applied at a distance. Torque is (b) Set the indicator to 'V". (To com-
measured in foot-pounds if the distance is pensate for the weight of the
measured in feet, or inch-pounds if the wrench.)
distance is measured in inches (Figure 1-36).
To change loot-pounds to inch-pounds or vice (c) Hang a known weight from the
versa, use the following formulas: wrench handle at any known
distance (one or two feet) from the
Foot-pounds multiplied by 12 = inch- center of the nut.
pounds (d) The known weight in pounds
Inch-pounds divided by 12 = foot-pounds multiplied by the distance In feet will
give you the feet-pounds of torque.
r-----12 This figure should agree with the in-
dicator reading on the wt./Inch. Exam-
ple shown: 50 lbs. x 2 ft. = 100 feet-
k pounds. The wrench indicator should
900
...... read 100 feet-pounds.
TORQUE = 12 INCH-POUNDS
Remember that any weight or
distance can be substituted in the
1 POUND formula. weight times distance
equals torque.

1 FOOT

HORIZONTAL
90°
TORQUE w 1 FOOT-POUND
x vf:.:)o 1 POUND
(146) UNITS FOR MEASURING TORQUE
Courtesy of John Deere Ltd

A I Center Line of Nut B = Point of $uoeneion

To torque nuts accurately, it is important to I 2192
select the proper size (i.e.. capacity) torque
(1-37)
wrench for the job. A good rule of thumb is to
select a torque wrench so that your working CHECKING TORQUE WRENCH FOR ACCURACY
range is within the middle two quarters of the Courtesy of John Deere Ltd
scale. For example, for nuts requiring between
150 and 450 foot-pounds of torque. use a 600
foot-pound capacity torque wrench.
Using A Torque Wrench
1. Torque wrenches can be pulled or
pushed. Apply the force steadily.
2. If a seizure occurs while tightening. back
oil the nut and retighten it with a steady
sweep of the handle.

36
 SHOP EQUIPMENT AND PRACTICES 1:21

PLIERS Diagonal Cutter Pliers: (Figure 1-39) are ideal

for pulling cotter pins, especially from slotted
Combination Pliers: have a slip joint which nuts. They may also be used for spreading the
allows them to open wider. These pliers are ends of cotter pins and cutting light gauge
intended for holding, twisting, pulling; they wire. Never use diagonal pliers for cutting
should not be used for tightening nuts (Figure large-gauge wire.
1-38).
Side Cutter Pliers: used to cut large gauge
wire.

Needle-Nose Pliers: are used primarily for

handling small objects and for reaching into
restricted areas, Never force them beyond
their gripping capacity.

Lock -Grip Pliers (Vise-grips): are specially

designed to clamp and hold round and flat ob-
jects. One jaw is adjustable to fit different
sizes of nuts, bolt heads, pipes, or rods. Never
(1-38) use these pliers on material where you don't
X ,?271
DON'T USE PLIERS ON NUTS want to mar the finish.
Courtesy of John Deere Ltd.

DIAGONAL CUTTER PLIERS SIDE CUTTER PLIERS

.,1,,

f ter' ------
0 7/
749Y.

NEEDLENOSE PLIERS LOCK-GRIP PLIERS

(1-39) Courtesy of John Deere Ltd

37
1:22 SHOP EQUIPMENT AND PRACTICES

Snap Ring Pliers: Snap rings fit into a bore or SINGLE DOUBLE RASP CURVED
casing (internal) or fit on a shaft (external). CUT CUT CUT TOOTH
Snap ring pliers are made tc spread or close
the rings just enough to allow removal or in-
stallation (Figure 1-40). Several types of pliers
are available to work with the different types
of snap rings.

X 2341 MILL MACHINIST'S RASP CURVED

FILE FILE FILE TOOTH
(1-40) SNAP RING PLIERS FILE
Courtesy of Owatonna Tool Company (1 -42)
Courtesy of John Deere Ltd.
Other Types 01 Pliers: Following are some
special types of pliers: battery (terminal nut)
pliers, water pump nut pliers. ignition pliers. Correct Use
hose clamp pliers. brake spring pliers, 1. Put handles on files: don't use them
retaining ring pliers, groove-grip snap ring without handles. Tighten handles as
pliers, horseshoe lock ring pliers, and slip- shown in (Figure 1-43)
joint (channel) pliers.
2. Cut only on the forward stroke. Apply only
enough pressure to keep the file moving.
FILES Lift the file on the return stroke.
Three important factors in identifying files 3. Get into the habit of tapping the file at the
are: length. type and cut. Length is measured end of a stroke to clear the teeth of chips.
from tip to heel (Figure 1-41), type refers to
shape or style. and cut refers to the kind and 4. Don't use a file when it is full of chips.
coarseness of the teeth. Clean it with a file card (Figure 1-43).
Four common types of cuts of files are shown A file card is a brush with short, stiff wire
in Figure 1-42. Mill files are generally used for bristles. If chips are left after using the file
tool sharpening and removing sharp edges card, they should be lifted out with a poin-
and burrs from cut and worn parts. Machinist's ted or flattened cleaning wire called a
files are used for filing and finishing machine "scorer" which is included with most file
parts. Rasp files are used for cutting wood cards.
and very soft metals. Curved tooth files are
used on aluminum and steel sheets. 5. The terms rough, smooth, and dead
smooth are used to indicate file finishes.
6. Keep oil away from files: it inhibits their
EDGE TANG cutting ability.
TIP
7. Draw-filing is the stroke used to finish flat
surfaces such as a gasket surface. To
FACE draw-file, take a machinist's file (Figure 1-
HEEL 43) and draw the file crossways over the
LENGTH surface with light pressure (Figure 1-43).
8. To keep files sharp. protect their surfaces
(1-41) when not in use. Do not throw files around
Courtesy of John Deere Ltd on the bench or into a drawer. Keep files
away from water to prevent rusting.

38
 SHOP EQUIPMENT AND PRACTICES 1:23

VISES
The size of a vise refers to the measurement
across the jaws. Four to six inch vises are
commonly found in heavy duty shops.

Correct Use
1. Never use a hammer to tighten or loosen a
vise; arm strength is sufficient.
2. Always use a vise big enough for the part
or type of work to be held.
3. When round parts must be held, soft metal
or hardwood jaws can be used to prevent
slipping or damage to parts. Whenever
X 2.302 finished surfaces must be held, be sure to
(1-43) TIGHTENING FILE HANDLE use soft metal jaw covers as shown in
Figure 1-44 so that the finish isn't marred.
4. Use a drill press vise (Figure 1-45) when
drilling small pieces of metal.

PROTECTIVE
JAW COVERS

X4211

(1-43) CORRECT METHOD OF DRAW-FILING

X 2.308
(1-44) MACHINIST'S BENCH VISE
Courtesy of John Deere Ltd.

X 2304 _
FILE CARD

(1-43) CORRECT US! OF FILES X 2403

CourtesY of John Deere Ltd. (1-45) DRILL PRESS VISE
Courtesy of John Deere Ltd.

.39
1:24 SHOP EQUIPMENT AND PRACTICES

HACKSAWS

Use And Care

1. Hacksaws can be adjusted to accept dif-
ferent length blades. A properly stretched
blade will vibrate with a clear humming
sound when plucked.
2. The teeth on a blade must point towards RIGHT WRONG
the front of the hacksaw frame. BLADE BLADE
X 2306
3. Blades are made with 14. 18, 24 and 32 (1-46) SELECTING THE CORRECT
teeth per inch. The rule of thumb for HACKSAW BLADE
selecting the correct blade is that two Courtesy of John Deere Ltd.
teeth should always be contacting the
material when cutting (Figure 1-46).
4. Apply cutting pressure only on the forward
stroke. Relieve the pressure on the return
stroke (Figure 1-46).
5. For efficient cutting of average metal,
work the blade at 40 to 50 strokes a
minute. Reduce this rate for harder
metals. There is a limit to the hardness of
metal that can be sawed with a hacksaw.
6. When cutting very thin material, such as
tubing, shift the angle of the saw blade as CORRECT WAY TO USE A HACKSAW
cutting progresses to allow as many teeth
as possible to contact the work at one (1-46) HACKSAWING
time (Figure 1-46). Courtesy of John Deere Ltd.
7. Except when starting, use the full length
of the blade on every stroke.
8. Usually hacksaw blades are not shar-
pened; they are thrown away when dull.
9. Wipe the blade occasionally with an oily
cloth to keep it from rusting. Also, keep
the blade away from other tools to
eliminate the possiblity of teeth being
broken or dulled.

bTILT BLADE
FOR MORE CONTACT

(1-46)
SAWING THIN TUBING
X 2.307 Courtesy of John Deere Lid

40
 SHOP EQUIPMENT AND PRACTICES 1:25

TAPS AND DIES

Taps
Taps are used for cutting internal threads. TAPER
There are many styles of taps; common ones
are taper, plug, bottoming. and machine
screw (Figure 1-47). A taper tap is used to tap
completely through the hole; it has a long PLUG
gradual taper that allows the tap to start
easily. A plug tap is used to tap threels part- 111011WW111!11111
way through. A bottoming tap is use° to cut UMEM *MIMIPPIIPPPPPOPIPPM11
threads all the way to the bottom of a blind
BOTTOMING
hole. A plug tap should precede a bottoming
tap, as the bottoming tap will not start well. A
machine screw tap is good for small diameter,
fine thread jobs. The plug tap is the most Z4213 MACHINE SCREW
widely used tap, and except for running
threads completely to the bottom of a blind (1-47) FOUR KINDS OF TAPS
hole, will cut satisfactory threads for most
jobs. Courtesy of John Deere Ltd.

Taps are also made to cut pipe thread. Since

pipe thread is tapered (3/4 inch in one foot)
only one tap is made for each pipe size.

Correct Use Of Taps

After determining the diameter and number of
threads per inch of the screw or stud that will
enter the tapped hole, use a tap drill-size
chart to find what size hole to drill. For exam-
ple, a 3/8 inch coarse thread stud requires a
5/16 inch hole. Place the tap in a tap handle, TAP WRENCH
and carefully start the tap in the hole (Figure KEEP TAP
1-48). Lubricate the tap with cutting oil. After SQUARE
threading the tap one or two turns, back it up WITH HOLE
a quarter to one-half turn to break the chip.
Repeat this process as you continue tapping. USE TAP
Be cz.-Ci.ful the hole does not clog with chips LUBRICATION
and ..:ause the tap to break. It may be WHEN WORK
necessary to withdraw the tap and remove the REQUIRED
chips. Taps are quite bratle: use them with
care. If they break off in the hole they are dif-
ficult to remove.

X4214

(1-48) USING THE TAP TO THREAD

A DRILLED HOLE
Courtesy Of John Deere Ltd.

41
1:26 SHOP EQUIPMENT AND PRACTICES

Dies Special taps and dies are illustrated in Figure

1-49. One form of rethreading the tool is
Dies are used to cut external threads. A die of shown in A. It is placed on the thread and
the correct size is placed in a diestock (hand- turned. 8 shows an internal thread chaser
le). The diestock is turned around the rod to used to clean up dirty or damaged internal
cut the threads. The rod end should be threads. The thread restorer. C. is handy for
beveled to make it easier to start the die. quickly reconditioning external threads. The
When cutting the threads, use cutting oil, axle rethreader, D, is placed around the good
back up the diestock every one or two turns. thread area, clamped shut. and then turned
and keep the die free of chips. Don't force; back over the damaged area. Nut or
turn easily. rethreading dies, E and F, can be turned on a
Dies are often adjustable in size so that you damaged thread. An ordinary box wrench can
can slightly enlarge or reduce the outside be used to turn them. G and H are spark plug
diameter of threads and improve the thread fit. hole taps. These are very handy to clean up
damaged or carboned plug hole threads. A
combination tap and die set for tube flare fit-
tings is illustrated in J. and a combination tap
and die set in K.

_..... 4

ca:Cro
imi= =120
cznto co=

c= 1.-11=1 %,1/4.19 p®

A Rethreading Tool D Axle Rethreader .1 Tap and Die Set for

13 Internal Thread Chaser E-F Rethreading Dies Tube Flare Fittings
C Thread Restorer G-H Spark Plug Hole Taps K Combination Tap and Die Set

(1-49) TAPS AND DIES

Courtesy of John Deere Ltd.

42
 SHOP EQUIPMENT AND PRACTICES 1:27

CHISELS PUNCHES

Flat Cold Chisel (Figure 1-50): the most com- Starting Punch (Figure 1.151): used to knock
mon chisel used by the servicemen. They are out rivets and to start or knock out straight or
used for cutting metal. Common uses of tapered pins.
chisels for a mechanic are to break rivets and Pin Punch: used for driving out pins after the
split nuts. starting punch can no longer be used. Don't
use a pin punch to start a pin moving: the slim
Cape Chisel: used for cutting keyways. shank could bend or break.
narrow grooves, and square corners.
Center Punch: used to mark the center of a
Round Nose Chisel: used for cutting semi- hole that is to be drilled. The mark ensures
circular grooves and chipping inside corners that the drill will bite in the right spot and
which have a fillet or radius. won't wander.

Diamond Point Chisel: used for cutting V- Aligning Punch: used to shift parts to line up
grooves and square corners. corresponding holes. Never use an aligning
punch as a center punch.

HANK

FLAT COLD CHISEL STARTING PUNCH

LI
t----.... 1
PIN PUNCH
CAPE CHISEL

ROUND NOSE CHISEL

CENTER PUNCH

X 2:::5 DIAMOND POINT CHISEL

X 2298 ALIGNING PUNCH
(1-50) CHISELS
Courtesy of John Deere Ltd
(1-51) PUNCHES

Courtesy of John Deere Ltd.

43
1:28 SHOP EQUIPMENT AND PRACTICES

Drift Punches (Figure 1-52): are long punches Correct Use Of Chisels And Punches
usually between one and two feet in length;
they are used for reaching hard-to-get-at 1. A chisel (or punch) should be held fairly
spots and for lining up. Some drifts are loose, so that the jarring vibrations are not
tapered, while others such as a brass drift are all transmitted to the hand. Also, the hand
a straight rod (Figure 1-53). is less likely to get injured in case of a
miss.
2. Wear safety glasses when using a chisel.
3. A chisel will cut any metal softer than it-
self. Always use a chisel that is big
enough for the job and a hammer that is
heavy enough for the size of the chisel.
This also applies to punches.
4. When grinding a chisel or punch never
hold it against the grinding wheel too
long. Dip it frequently in water or coolant
to keep it cool. Otherwise it will lose its
DRIFT PUNCHES temper and aecome soft

Tool Point 5. The end of chisels and punches will tend

No. Size Lengt h SST: to flair out after repeated blows from a
hammer. Keep the head ground back as
DP5 5132" 8" 318"
shown in Figure 1-54.
DP6 3116" 9" 112"
DPS 114" 12" 518"
DM 5116" 11" 518"
DP12A 318" 16" 314"

(1-52)
Cot'nesy of Mac Tools

klgt° BRASS DRIFT

BD8 x '':',7 WRONG

(1-54)
RIGHT

To get at driving jobs where a soft GRIND BACK CHISEL AND PUNCH HEADS
punch is reciuired. 8" long, 3/4" stock.
Courtesy of John Deere Ltd.
(1-53)
Courtesy of Mac Toots

44
 SHOP EQUIPMENT AND PRACTICES 1:29

TWIST DRILLS . curately; for example, if the length of the cut-

ting edges are unequal from grinding, the
Twist drills are made of either carbon tool hole will be larger than the diameter of the
steel or high-speed tool steel. Carbon steel drill.
will lose its temper if excessively heated and
allowed to cool, whereas high-speed steel can Figure 1-58 illustrates the most commonly
become red hot and then cool and still not used drill shapes. The lips do the cutting and
lose its temper. Twist drill terminology is therefore must be ground to a sharp edge.
shown in Figure 1-55. These lips or cutting edges must be of
uniform length. The portion behind the lips is
Twist drills have four classifications: frac- ground down on an angle to provide lip
tional drills rise in size from 1/84" by 84ths up clearance.
to 1" and larger. number drills rise in size
from No. 80 to No. 1, with diameters For steel and cast iron, cutting edges are
measuring from .0135 inches to .228 inches; ground on a 59 degree angle to the drill axis
letter drills range in size from A to Z. with or 118 degrees included angle as shown in
diameters from .234 inches to .413 inches: "A". Note that the lip clearance angle on "A"
metric drills are generally listed from 1 mm is 12 degrees to 15 degrees. "Er illustrates a
upwards in .5 mm increments. drill ground to drill heat-treated steels and
LIP OR CUTTiNG DEAD drop forgings. Note that the included angle is
EDGE CENTER greater and the lip clearance angle is 12
degrees. When drilling softer material such as
wood. hard rubber, fiber, or soft cast iron, a
FLUTE BODY much smaller included angle can be used as
CLEARANCE shown in "C". When any unusual material
such as spring steel must be drilled, consult a
MARGIN BODY machinist's handbook to obtain the correct
angles and shapes.
AXIS OF
DRILL Note: Always be sure to keep drills cool
while grinding by dipping them oc-
casionally in water or oil.
IW

DEAD
MARGIN CENTER

CUTTING
LIP
SHANK

o
THE POINT

LIP CLEARANCE

(1-55)
X 2311 TWIST DRILL
Courtesy of John Deere Ltd.
o
Sharpening Drills
To drill accurately drills must be sharp. Drills
are sharpened by grinding them either
freehand or with a jig that attaches to a grin-
der. It is important that drills be ground ac- o
X 2313
(1 -56) COMMON SHAPE OF DRILLS
Courtesy of John Deere Ltd.

45
1:30 SHOP EQUIPMENT AND PRACTICES

Correct Use
1. For low speed drilling, carbon tool steel
drills can be used.
2. For high-speed drilling, use drills of high-
speed tool steel.
SHANK
3. Always center punch before drilling. X 2260
4. After the drill has enlarged the center (1-56A) COMMON SCREWDRIVER
punch mark slightly and before the whole Courtesy of John Deere Ltd.
point has entered the material. check to
see that the hole is correctly centered. If
the drill is not entering the right spot. it Phillips-Head Screwdriver (Figure 1-60): will
can be drawn over by making a chisel cut
rot slip sideways out of the cross slots of a
on the side to which the drill should be Phillips-head screw. but more force must be
drawn (Figure 1-57). exerted in keeping it in the slots. If the bit gets
damaged, it is not practical to repair it.
5. Always use a lubricant to cool the drill.
Clutch-Head Screwdriver: is used with
CHISEL. screws for sheet metal and trim where a neat
CUT appearance is desired. The tip of the
screwdriver is very strong and stays in the
screw opening with only moderate pressure.

Offset Screwdriver: used where space is

limited and the screw is hard to reach. Bits
are normally at right angles to each other,
allowing the screw to be turned a quarter turn
CENTER PUNCH
MARKS
at a time by using opposite ends alternately.
Y La t1 Use the offset screwdriver cautiously as the
(1-57) HOW TO DRAW THE DRILL BACK bit has a tendency to jump out of the slot and
TO CORRECT CENTER chew up the screw head.
Courtesy of John Deere Ltd

6. In work where extreme accuracy is Correct Use

specified drill the hole just under the 1. Never use a common screwdriver as a
finished size. Follow the drill with a boring
cold chisel, a punch. or a prying bar. If you
tool to correct any eccentricity and then must tap on the screwdriver, use one
bring the hole to the exact diameter with a
made for tapping.
straight reamer.
7. Note that as the diameter of the drill in-
2. Don't twist the shank of a standard
screwdriver with pliers or a wrench. If
creases the recommended speeds necessary, use a heavy-duty screwdriver
decrease proportionally, also that as the with a square shank made for this pur-
rate of feed is increased the recom. pose.
mended speeds increase more or less
proportionally. 3. Never use a screwdriver to check an elec-
trical circuit where the amperage is high.
SCREWDRIVERS 4. A good rule is never put any part of your
body in front of a screwdriver bit. It could
Common Screwdriver: one of the most injure you.
frequently used tools by a mechanic. It is
made for straight slot screws and comes in 5. Be sure the screwdriver bit fills the slot in
various shank lengths and thicknesses and bit the screw head (Figure 1-588). Too small
widths and thicknesses (Figure 1-58A). a bit will twist and chew up the screw.

46

1
 SHOP EQUIPMENT AND PRACTICES 1:31

o o
PHILLIPS-HEAD
HOW A SCREWDRIVER POOR FIT DAMAGES
SHOULD FIT THE SCREWDRIVER MO
SCREW SLOT SCREW SLOT
X 2261

(1-58B) BE SURE THE SCREWDRIVER FITS

THE SCREW SLOT
Courtesy of John Deere Ltd.

6. If a screwdriver bit becomes rounded or

broken. it can be reground as follows:
grind the tip until it is straight and at right CLUTCH HEAD
angles to the shank (Figure 1-59). The X 2283
sides should have very little taper and
should never come to a sharp point at the
tip. Never hold the screwdriver against the

it
grinding wheel for long periods. Dip the
bit in water to keep it cool.

STARTING (SHOWN HOLDING SCREW)

RIGHT WRONG

X 226 2
(1-59)
GRINDING A SCREWDRIVER BLADE
Courtesy of John Deere Ltd. OFFSET

Starting Screwdriver: used for removing and (1-60) SCREWDRIVERS

installing screws in places difficult to reach Courtesy of John Deere Ltd.
with the hand. Once a screw is started, a com-
mon screwdriver can often be used to finish
the job. Other starting screwdrivers have
twisting centers or are magnetized to hold the
screws.

47
1:32 SHOP EQUIPMENT AND PRACTICES

SOLDERING TOOLS 5. Soldering a copper wire connection is

illustrated in Figure 1-61. Remove heat af-
Soldering is the process of joining two pieces ter fhe solder has thoroughly penetrated
of metal by using a third metal as an adhesive. the joint, and hold the two pieces rigid un-
Unlike welding. soldering does not involve til the solder cools and sets. Always use
melting the two metals being joined. Standard rosin core solder when doing electrical
solder melts at 800°F., far below the melting work.
point of most metals.
Solder is a mixture of varying combinations of
ROSIN CORE
tin and lead. Hard solder contains a high SOLDER
proportion of tin, whereas soft solder has a
low proportion of tin. Solder is available in
stick and in wire rolls. Some types contain
their own flux, while others must be dipped in
flux or have flux applied to the joint areas.
(Flux is a substance such as borax or rosin
that cleans the metal of oxides and helps the
solder fuse the two metals together.)
There are three common methods of X 2324
soldering: (1-61) SOLDERING COPPER WIRES
1. Soldering Irons electric soldering irons Course Sy of John Deere Lid.
come in various sizes ranging from 18
watts for a small pencil iron to 400 watts 6. Soldering a lap joint is illustrated in Figure
for a large iron. The area and amount of 1-62.
heat required for a job will decide which

2.
size iron is most suitable.
Soldering Guns electric soldering guns
are used to solder electrical connections.
The :rigger switch can be turned on and
/
()SURFACES
LAPPED
ARE

off as required.
SEAM IS
3. Torches oxyacetylene torch or a HEATED
propane torch kit can be used to heat TO FUSE
metals for soldering. (A propane torch kit SOLDER\
has a disposable propane cylinder and
soldering tips. as well as other ac- THIN SOLDER HERE X4216
cessories.) Broad areas can be soldered
faster with a torch because it supplies (1-62) SOLDERING COPPER WIRES
more heat. There is a danger with torches,
however of overheating the material and Courtesy of John Deere Ltd.
of damaging nearby parts such as hoses.
Soldering Hints
So Merino Procedures 1. Keep soldering irons or tips smooth by
filing them.
1. Thoroughly clean the work to be soldered,
removing all rust scale and oxidation. A 2. Excessive solder can be removed from a
quick brush over with a wire brush is not tip with a cloth when the iron is hot.
good enough.
3. Don't let irons overheat: turn them off
2. Before using a soldering iron or tip, it when not in use.
must be tinned. To tin an iron. heat it and
apply solder to it. 4. Metal is ready for soldering when the
solder melts freely and sizzles.
3. Heat the pieces to be soldeeed and apply
flux if it isn't included in the solder. 5. When using a propane torch kit for
soldering in an area where nearby parts
4. Always apply solder to the work, not to the could be damaged, heat the tip and then
iron. turn the propane off before using the tip.

48
 SHOP EQUIPMENT AND PRACTICES 1:33

THREAD RESTORER KIT

When threads in castings or other expensive
parts are damaged or completely stripped.
they can be repaired with a thread restorer.
Helicoil thread restores (Figure 1-63) are the
most common type. A basic Helicoil kit con-
tains a Helicoil insert of a certain size and a
corresponding tap and Helicoil installation
tool. More complete kits are available that
contain various sizes of Helicoil inserts. taps.
and winding tools. Procedures to install a
Helicoi are as follows (Figure 1-64).

DRILL

(1.63)
Courtesy ol Helicoil Products

TAP
1. Drill out damaged or stripped threads
using the drill size specified in the
Helicoil kit. Drill to an adequate depth
right through. or for blind holes. to the bot-
tom.
2. Using the tap supplied with the kit, cut the
threads that will receive the insert.
3. Taking the installation tool supplied
(Figure 1-65). screw the helicoil insert on
the tool. The insert should be screwed far
enough so that the tang (Figure 1-66) is
engaged in the slot at the bottom of the
tool. Now screw the insert into the tapped
hole until it is one-quarter to one-half turn
below the surface of the hole. INSTALL
4, Finally the tang must be removed. Place
the square end of a punch (no bevel) on (1-64) INSTALLING A HELICOIL
the tang and strike it sharply with a ham-
mer. The tang will break off at the notch. Courtesy ol Helmoil Products

49
1:34 SHOP EQUIPMENT AND PRACTICES

Once installed. Helicoil inserts stay in place BRUSHES AND SCRAPERS

for this reason: in their free state the inserts
are larger than the taped hole (Figure 1-67). Brushes and scrapers are used for cleaning
Thus when they are installed they are com- lobs, for removing dirt. grease. carbon build-
pressed, and the spring action of compression up. rust, scale and paint from parts and equip-
presses them against the sides of the tapped ment. Some types of scrapers likely to be
hole, holding them in place. found in a repair shop are illustrated in Figure
1-68. The illustrations are taken from a tool
HELI -COIL. INSTALLATION TOOLS catalogue. Common types of brushes are
shown in Figure 1-69, and specialty brushes in
Figure t-70.

STANDARD TYPE

(1-65)

CARBON SCRAPERS
PREWINDER TYPE
long blade
Courtesy of Helicon Producis
Tool No. 1 Type Noodle Imp
HELICOIL STAINLESS STEEL INSERTS 5111 Wood Handle 114'a

TANG
SPH1
SP.
Plastic Handle
Plastic Handle r
1144"

(1-68) SCRAPERS
NOTCH CourlesY of Mac Toots

S"'""IgC:::14
STANDARD SPARK PLUG CSIO

(1-66)
Courtesy Of Neircod Products
FLEXIBLE WIRE
CARBON SCRAPER
coo 10" long, 1" wide.

STANDARD PUTTY KNIFE

P1(1 LW' blade.
PK2 Heavy-duty, Thick Stiff Blade-
14i".
PKtO Heavy-duty, Thick, Stiff Blade
3".
PK12A Standard-duty, Flexible Blade
3".

(1-67) HEILI-COIL INSTALLATION Counesy of Mac Tools

Counesy of Hewed Products

50
 SHOP EQUIPMENT AND PRACTICES 1:35

WBIO

HAND WIRE BRUSH SHOE HANDLE WIRE BRUSH

W810 Length 14.'.

HEAVY-DUTY CARBON
CLEANING BRUSH
W115 End Brush. W diameter with W
shank.
W86 Similar to the WB8. r in diam-
eter. Vi shank.
WB7 Cable Twist 1" diameter with ve ADAPTOR FOR
shank. DRILL CHUCK
CAI W shank. WW4
CA2Adaptor for Drill Chuck. W shank.
CA3Adaptor for Drill Chuck. rh~ shank. STANDARD
OBIS
WIRE WHEEL BRUSH
NYLON BRISTLE (1-69) COMMON BRUSHES
Courtesy of Mac Tools
MOTOR CLEANING BRUSH

CRANKSHAFT OIL HOLE CUMMINS DIESEL BRUSH PW34 Aluminum handle economy
size polypropylene.
BRUSH SET NH1 Stainless steel bristle handle
CSN Set of two Tynex nylon brushes to be used when changing injector while NYLON OIL LINE BRUSH KIT
5/is and 7132 x 2 x 10. in truck. OLK Tynex nylon brushes for: feed
DETROIT DIESEL BRUSH CUMMINS DIESEL BRUSH line, block oil return lines, overhead rocker
001 NH2 Stainless steel bristle cut for feed lines, valve guides, cam and crank-
Stainless steel bristle with handle
to be used when changing injector while power, cleans or polishes entire copper. shaft.
in truck. Best used as a bench tons VALVE GUIDE BRUSH SET
314" PARTS WASH BRUSH VOCK Set includes sizes V4. 5116. "ht.
'3/32, Yu, and 1/2.

(1-70) SPECIALTY BRUSHES Courtesy of Mac Tools

SNIPS
Snips are used for cutting sheet metal and
other sheet material like that used for gaskets.
In a repair shop snips are used for such lobs
as cutting shim stock, sheet metal for small
fabrication jobs, and gasket material.
Both straight cutting and circle cutting snips
are available (Figure 1-71).

CIRCLE SNIPS
STRAIGHT SNIPS (1-71)
Courtesy of Gray Tool Company

51
1:36 SHOP EQUIPMENT AND PRACTICES

REAMERS Screw Extractors

Reamers (Figure 1-72) are used for cleaning. When a stud. pipefitting or nipple breaks off
enlarging, shaping holes. Some uses for below the surface. a stud extractor is needed
reamers in the heavy duty shops are removing to remove it. Several types are available. the
burrs. aligning holes in sheet metal. starting most common known as an "Ezy Out". It is a
taps. and resizing holes when new bushings hardened tapered rod with coarse, sharp, left-
are installed. handed spirals. It has a square on top. it is for
turning the extractor with a wrench. To use
Reamers are available singly in fixed and ad- the extractor. a hole is drilled in the exact
justable sizes or in sets: they can be turned by
center of the stud. This must be done carefully
hand in a tap wrench or be put into an electric as most studs are hard and difficult to drill.
drill. Adjustable reamers are usually turned by Some extractor kits are available with guides
hand. Note that reamers must never be turned (Figure 1-73) that center the drill in the hole
anticlockwise in a hole as they may jam and and keep it straight. If a guide isn't available.
the cutting blades could break Always turn a small pilot hole drilled first will help. Turn
reamers clockwise. the extractor into the hole, apply a firm
pressure on the wrench and back out the stud.
This must be done carefully. as it is easy to
break off the extractor in the hole further com-
plicating the problem.
At times you will find broken studs and pipefit.
tings so tight an extractor can't remove them.
In this case drill out the piece close to its
threads. then tap the hole with the correct
sized tap.
Getting out broken studs and fittings is an art
learned through practice. Observe the tricks
and techniques of experienced mechanics
doing the job. For example. one trick you
might see is heating the stud or surrounding
casting with a torch, then quenching the stud.
STRAIGHT
This will sometimes shrink the stud enough so
REAMER
it can be removed with an extractor. The point
Courtesy of Mac Tools
to remember about removing broken studs or
fittings Is that they broke off because the
threads were extremely tight or frozen in the
first place and so they will probably be dif-
ficult to get out.

r--- DRILL
i i
I 1 DRILL
GUIDE
K02043
KD2044

REPAIRMAN'S REAMERS flW REMOVING

rIl BROKEN
*02043ReamerRange W to W. STUD
*02044ReamerRange VI( to r. KA
STUD i.) WITH
EXTRACTOR EXTRACTOR
xnut
(1 -72) REAMERS Ab

Courtesy of Mac Tools

EXTRACTOR FOR REMOVING BROKEN STUDS
(1-73)
Courtesy of John Deere LW

52
 SHOP EQUIPMENT AND PRACTICES 1:37

Extractor sets contain extractors in several WIRE SPLICERS

sizes. guides in several sizes to center the
drill, and other useful stud extracting items. Wire splicer (Figure 1-76) are special pliers
made for use with electrical wiring; they strip
In an emergency, a diamoi;d-point chisel insulation from wire, cut wire, and crimp ends
sometimes can be used to remove a broken to wire.
stud (Figure 1-74). Drive the chisel into the
stud after drilling a small hole in the center of
the stud. Then turn the chisel carefully with a
wrench.

(1.76)
WIRE SPLICER

PULLERS
Three basic pulling problems are illustrated in
Figure 1-77. The solutions to these problems
are shown in Figures 1-78, 1-79 and 1-80.
Examples of pulling jobs are shown in Figure
1-81.
(1-74) USING CHISEL AS EMERGENCY
STUD REMOVER
Courtesy of John Deere Ltd
4--- PULL

STUD PULLER
4111 PUSH
To remove unbroken studs, use a stud puller. pulling
Drop the stud puller over the stud to be something
removed (Figure 1-75). Use a "T" or flex hand- PULL
le to turn the stud out. The puller off a shaft
automatically grips the stud with a knurled ec- Removing a gear, bearing. wheel. pulley. etc . to replace
centric as pressure is applied. One size fits it or get at another Part
almost all studs. In all stud removals, use a
generous amount of penetrating oil.

PULL

pulling
something PULL

out of a hole
Internal bearing cups. retainers or oil seals are usually
pressfitted and are difficult to remove

111. PUSH

1110 PULL
pulling
(1-75) STUD PULLER FOR UNBROKEN STUDS
a shaft out 01 PUSH
Courtesy of John Deere Ltd
of something
A transmission shall or pinion shalt 4 often hard to
remove from a bore or housing.

(1.77) BASIC PULLING PROBLEMS

Courtesy of Owatonna Tool Company

53
1:38 SHOP EQUIPMENT AND PRACTICES

the tools to use...

nithe problem...
to grip and pull
a gear, bearing, iii lit
Vtt
t.
wheel, pulley, etc.,
from a shaft... Hydraulic jaw.
type puller. for
Jaw -type puller.
de extra force and
convenience.
the solution... either Haw Or
3jaw. depending
Both Haw and
3-jaw versions
upon the job. are avalleble.

otzjGet a grip on
the outer
circumterence Puller with bearing pulling
attachment. Provides "knife-
like" edge to get behind
component.

Use a pulling
attachment to
gel behind

,;:mUse threaded
adapters On
threaded studs
Pushpotter with attachments.
Above, matefemale adapters
can thread directly Into tapped
holes on component. Right.
splutter gets behind Component
to prevent damage.
Slide hammer
Get a firm grip
through spokes Special pullers
designed to do
Vr puller with
selected
attachments.
specific jobs.

OE Adapters
Variety used to protect shaft. bridge a hole. thread
Loa Utilize tapped
holes to pull
into tapped holes. assist inStaltatIOn of component.

(1-78) PULLING FROM A SHAFT

Couttesy of Owatonna Tool Company

54
 SHOP EQUIPMENT AND PRACTICES 1:39

the tools to use...

the problem ...
to grip and pull
an internal
bearing race, Designed for use with
Push-putters or stole
hammer pullers. internal
retainer, oil ti..,
pulling attachments
provide a straight pull.
seal, etc.... prevent damage to
housings. Various sizes
are offered.

the solution ...

Push-puller in combination
with internal pulling attach-
ment. Both mechanical and
hydrauncaiippowered
versions are available
........ .<1.L i

I li II

Here a slide hammer

puller is combined with
an internal pulling
attachment Ideal for
removing pads from
blind holes. especially
Whole pads within a "blind hole" in a housing when there is no housing
do present a challenge. there are pullers to to brace puller legs
solve it By extending the narrow jaws of an against.
internal pulling attachment through the center
of the part to be pulled. a straight pull is
assured, and damage to the housing is avoided.

- /
When there is a shalt to
bear against. a forcing
screw of proper size may
be used in cOmbination
with an internal pulling
attachment.

.
(1-79) PULLING FROM A HOLE
Courtesy of Owatonna Tool Company

55
1:40 SHOP EQUIPMENT AND PRACTICES

iS3the problem...
the tools to use...

to grip and pull Pushpuller With

threaded adapter
Use a mechanical or
a press-fit hydraulic puller,
depending on the site
Of the shalt to be
shaft from pulled.

a housing...
the solution...
Female threaded
adapter allovirs you to
thread onto shaft
directly tot pull.

=) Malefemale threaded
adapter threads into
tapped hole of shaft
for direct pull,

You can *Vet a hold** on the shaft if its end

is threaded.
When the housing lacks
sufficient surface for
the puller legs to bear
against. a pulling
attachment (shown
above) may be used to
provide support,

ADAPTERS
FEMALE ADAPTERS
Fasten to the male
Or, use a malefemale adapter to engage a threaded end of shalt
.011 to pull while pushing
tapped hole in the end of the shaft. against the housing.
selir
Sometimes. we can push a shaft through a Slide hammer puller MALEFEMALE
housing. rather than pulling it out. In with threaded

ift
ADAPTERS
applications of this type, the puller legs must adaptereither Thread into shalt to
be securely fastened to the housing and the malefemale or putt shaft white pushinc
female. against the housing.
screw may simply bear against the shaft.

(140) PULLING OUT A SHAFT Courtesy of Owatonna Tool Company

56
 SHOP EQUIPMENT AND PRACTICES 1:41

EXAMPLES OF PULLING JOBS Correct Use Of Pullers

1. Don't use a hammer or a pry bar: use a
puller.
2. Select the right size puller: the puller
must have the correct reach and spread
for the job.
3. Don't overload a puller:
(a) For manual. screw-powered pullers.
the puller screw must be at least
hall as large (in diameter) as the
shaft of the pulling job.
A roller bearing cone is removed by jaw-type (b) For hydraulic pullers. the maximum
puller "knife-like edges of pulling at- force exerted in tons should be 7 to
tachment fit behind bearing 10 times the diameter of the shaft in
inches. e.g..

For Shaft Use Hydraulic

Diameter Puller With

0 - 2" 171/2 ton ram

2" - 31/z" 30 ton ram

31/z" - 51/2" 50 ton ram

4. The tonnage capacity of a Push-puller is

Reverse idler shalt is pushed from trans- reduced as the legs get longer. Also.
miStOn case Legs of Push-puller are con- longer legs increases the chances of the
nected to housing with malefemale adapters. legs bending. breaking or misaligning.
Always use the shortest legs possible to
/. do the job.
5. Place a shaft protector over the end of
shaft before installing a puller.
6. Tighten the adjusting strap bolts when
using a jaw puller.
7 Be sure the set up is rigid and the puller
is square with the work.
8. Apply force gradually. The component
should give a little at a time. Do not try to
speed the removal by using an impact
An internal pulling attachment is used in wrench on the screw.
combination with a slide hammer to remove
an oil seal from a housing 9. If you have applied maximum force and
the part does not move. go to a larger
(1-81) capacity puller.
Courtesy 0 Owatonna Tool Company
10. Clean and lubricate the forcing screw
frequently. from threads to tip. to give it
long service life.
11. When installing parts that must be forced
into place. normally go to a shop press
rather than trying to use a puller. When
in doubt ask for help.

57
1:42 SHOP EQUIPMENT AND PRACTICES

PIPE AND TUBING TOOLS

Tubing Cutter: used to cut tubing made of

copper. aluminum. or steel (Figure 1-82). The
cutter is clamped around to the tube and turn-
ed. As the tool is turned, a sharp wheel cuts
into the tubing. Pressure is slowly increased
by turning the knob on the end until the tube
is cut off cleanly. Once cut, the end of the
tube must be reamed back to size. otherwise
flow in the tube could be restricted. The
reamer attached to the cutter is used for this
purpose. Tubing cutters are sold separately or SINGLE FLARE DOUBLE FLARE
sometimes in kits which include a cutter, a (1.84)
tube flaring tool. and a tube bending tool.
Bending Tool: is used to bend tubes uniformly
without crimping them. To use a spring ben-
der (Figure 1-85), slide the correct size bender
over the tube. and bend it applying pressure
with your thumbs. To use a plier-type bender
(Figure 1-86). place the tubinc, in the shaped
groove of the bender and squeeze the han-
dles.
(1-82) TUBING CUTTER

Flaring Tool: is used to flare the end of cop- )igina);)1»doiliikwillisimap)

TB1
per. brass, steel, or aluminum tubing in
preparation for a connection. To make a (1-85) SPRING-TYPE TUBE
single flare the tubing is placed in the correct BENDER
sized hole in the split support clamp (Figure 1- Courtesy of mac Tools
83) with the end of the tube protruding just
beyond the clamp surface. Then the yoke part
of the tool is placed over the clamp, and the K-D 2189
threaded taper is tightened down on the end
of the tubing. The taper causes the tube end T17,

to flare, providing a seal when the fitting is

tightened. Note: don't forget to install the fit- (1-86) PLIER -TYPE
ting before flaring the tube. because you can't TUBING BENDER
put it on afterwards.
Courtesy of mac Tools

(1.83)

Single flares are adequate for some jobs. but

in places where a stronger connection is
required a double flare is used. A double flare
is made in two steps. Using a part provided in
flaring kits. the end of the tube is first folded
inward (Figure 1-84). Then. the end is flared as
described above.

58
 SHOP EQUIPMENT AND PRACTICES 1:43

QUESTIONS HAND TOOLS, SHOP 9. Snap ring pliers are made for removing
SAFETY, SERVICE LITERATURE either or snap
rings.
1. The three basic pieces of information
that should be in a parts list are: 10. After cutting a piece of tubing with a
tubing cutter. the end should be:
(a) make. color. and size of the
machine (a) filed smooth
(b) type. model. and size (b) reamed
(c) make. model. and serial number (c) left as is
2. True or False? A parts book and a ser- (d) expanded
vice manual are essentially the same.
3. Fires are divided into how many classes?
11. True or False? Use a double flare on
tubing when a double nut is required.
(a) 2
12. The average lip clearance angle of a drill
(b) 4 is from:
(c) 5
(a) 59`' to 65°
(d) 3
(b) 8° to 12°
4. True or False? Fire extinguishers are (c) 118° to 130°
classed according to the type of fire they
will extinguish. 13. If a drill bit runs off center when starting.
it can be brought back by:
5. List the six parts of the body a heavy duty
mechanic can most commonly injure. (a) using a larger drill bit
fb) leaning the drill to one side
6. Which is a properly ground screwdriver.
A or B? (c) making another center punch mark
(d) making a chisel cut on the side to
A which the drill should be drawn
14. The narrow raised rib that runs the
length of the twist drill and finishes the
hole to size is called the:
(a) lip
(b) flute
B
(c) margin
___----_ (d) web
15. The size of a twist drill can be measured
with a micrometer:
(a) over the land
(b) over the flutes
7. Soft faced hammers are used rather than (c) over tho margin
steel hammers because they: (d) over the web
(a) apply softer blows 16. Number drill sizes range from:
(b) are quieter
(a) No. 1 to 80
(c) jar the hand less
(b) No. 1 to 95
(d) protect machined surfaces
(c) No. 1 to 26
8. True or False? Combination pliers are (d) No 1 to 75
intended to be used as substitutes for
wrenches.

59
1:44 SHOP EQUIPMENT AND PRACTICES

17. For general purpose work the cutting lips 23. What precaution must be taken with a
of a drill should be ground to an included reamer not to dull its cutting edge?
angle of:
24. A multiplier is a geared attachment that
(a) 135 gives a mechanical advantage through:
(b) 118
(a) bevel gears
cc) 180 (b) helical gears
(d) 145
(c) planetary gears
18. The difference between a tap and die is:
25. What are four common types of chisels
(a) a tap cuts threads in a hole. and a used in the heavy duty trade?
die cuts threads on a rod
(b) a tap cuts threads on a rod. and a
26. The terms rough. smooth. and dead-
die cuts threads in a hole smooth refer to:
(c) a tap cleans threads. and a die cuts (a) hacksaw Wades
new threads (b) drill tips
19. Three types of taps are: (c) file cuts
(a) taper. pin. and bottoming
27. Name three common types of punches.
(b) taper. plug. and bottoming
(c) taper. bottom. and cape
28. Name four types of screwdrivers.
29. Name four types of material used for
20. A plug tap is used: hammer heads.
(a) to thread a blind hole 30. Name four types of pliers.
(b) after a taper tap
31. The file with the largest teeth is a:
(c) before a taper tap
(a) double-cut file
(d) alter a bottom tap
(b) flat file
21. Which of these taps is referred to as a (c) rough or coarse-cut file
plug?
32. A file that has two series of diagonal
rows of teeth cut across its face is
(a) called:
(a) rasp cut
(b) doubll cut
(c) single cut
(b) jiN10111111111iiii
PPOPPI/PlimPPPwri (d) fine cut
33. What does the term "drawli!e" refer to?
34. What are the minimum umber of
(c) hacksaw teeth that should be in contact
with the work?
35. When culling with a hacksaw. pressure
should be applied to the blade:
22. To remove a broken stud. center punch (a) in both the forward and reverse
it. then' stroke
(a) drill a large hole in the center (b) on the forward stroke only
(b) drill a hole 'art way down (c) on the reverse stroke only
(cl drill a pilot hole
(d) drill it right out to the threads

Go
 SHOP EQUIPMENT AND PRACTICES 1:45

36. In reference to hacksaw blades, pitch 46. What is the advantage of a tubing
refers to the per inch. wrench over a standard open-end
wrench?
37. When really tightening a vise, it is ad-
visable to tighten it with: 47. Identify the following socket drive ac-
cessores.
(a) the handle of the vise only
(b) a piece of pipe on the handle to get 2.
leverage .iiiirmakt' i
wo
(c) a hammer to strike the handle and
secure the vise
38. What is the purpose of soft jaws for a
bench vise?
39. Normally, hacksaw blade teeth should
point:
(a) toward the right hand
(b) toward the handle
61=. 5.
(c) away from the handle
40. A typical box wrench has:
48. A torque wrench is recommended to
(a) 10 notches provide:
(b) 8 notches (a) extra leverage
(c) 12 notches (b) adaptability of sockets
(c) safeguard on over stressing parts
41. Wrench sizes are governed by the: (d) "non-slippage" of sockets
(a) thread length
(b) length of the bolt 49. When the torque wrench lever length is
12 inches and the force applied to the
(c) width of the bolt head across the handle is 5 pounds. the torque produced
flats is:
(d) width of the bolt head across the
corners (a) 10 ft.-lbs.
(b) 50 ft.-lbs.
42. What is the main rule when using an ad-
justable wrench? (c) 2 ft. -tbs.
(d) 5 ft.-lbs.
43. Open and box end wrench sizes increase
in steps of: 50. In selecting the right sized puller, it must
have the correct and
(a) 1/8 inch for the job.
(b) 1116 inch
51. For hydraulic pullers. the maximum force
(c) 1/32 inch exerted in tons should be
(d) 1/46 iiicn times the diameter of the shaft in inches:
44. Spanner wrenches are used on nuts with: (a) 1 to 2
(a) 12 points (b) 4 to 5
(b) 6 points (c) 12 to 15
(c) notches (d) 7 to 10
(d) flanges
45. Why is the head of an open end wrench
made with an offset?

61
1:46 SHOP EQUIPMENT AND PRACTICES

52. A good rule with pullers to prevent bend-

ing. breaking or misaligning the puller
legs is to use:
(a) the largest legs possible
(b) the shortest legs possible
(c) the smallest legs possible
(d) the straightest legs possible
53. The point of a soldering iron must be
before being used for
soldering.
54. What is the purpose of soldering flux?
55. Soldering electrical wiring should be
done with solder and:
(a) resin flux
(b) acid flux
(c) caustic flux
(d) soap flux
56. The figure below shows installation of a:
(a) bolt
(b) hell-coil
(c) spring

11;111;;;;; et I

62
 SHOP EQUIPMENT AND PRACTICES 1:47

AIR, ELECTRIC, AND HYDRAULIC

POWER TOOLS

IMPACT WRENCHES
Impact wrenches are driven by air (Figure 1.
87) or by electricity: they work in either direc-
1" DRIVE IMPACT WRENCH
tion, and come with 3/8" 1/2". 3/4" and heavy
duty 1" drives. Their advantage over hand (1.87) IMPACT WRENCHES
wrenches is that they are much quicker and Courtesy 0 Mac Tools
require less effort to use. The time taken to do BENCH GRINDER
such jobs as loosening or tightening wheel
nuts or U-bolt nuts will be cut in half by using All repair shops have bench grinders (Figure
an impact wrench. A rule of thumb on when to 1-88). They are used for sharpening. cleaning.
use impact wrenches is to use them wherever shaping. wire brushing. buffing. Bench grin-
possible to save time and energy. However. ders have two drives. Often a medium-grit
where torque is critical, do final tightening grinding wheel will be on one side and a fine
with a torque wrench. wheel or wire brush on the other.
Correct Use Correct Use

Some impact wrenches have an adjustment to I The shaft that holds the right-hand wheel
gauge the amount of torque the wrench has right-hand threads, while the shaft
delivers, but most don't. Since it's very easy to that holds the left-hand wheel has left-
overtighten nuts with an impact wrench, it's hand threads. Remember this when
necessary to develop a feel for how much changing grinding wheels
torque the impact wrench puts on nuts. To 2. Tool rests should be approximately 1/16"
help get this feel. tighten a few nuts with an from the wheel and should be at or below
impact wrench and then put a torque wrench the center of the wheel. Rests can be set
on the nut and see how much torque you have at various angles for sharpening tools.
applied. Be alert when using an impact
wrench don't damage parts by overtightening 3. Take the following safety precautions
them. when grinrong: always wear safety
glasses even if the grinder has a shield.
Air impact wrenches require lubrication. See Never wear loose clothing or jewelry.
the maintenance instructions for the wrench Don't have anything near the grinder that
or ask a journeyperson. Three methods of a spark could explode.
lubricating air wrenches are (1) a special
lubricator located in the incoming air line, (2) 4. Place the work on the tool rest when grin-
an oil reservoir in the handle or (3) squirting ding: don't lift it up.
lubrication into the air intake by hand. Electric
impact wrenches are usually lubricated by the
5 Move the work back and forth across the
wheel so that the wheel doesn't develop a
manufacturer on assembly. but should oc-
groove. Don't use a wheel that is cracked
casionally be cleaned and relubricated.
or flawed.
6. Dip the work frequently so that it doesn't
lose its temper.
7. Give a wheel a chance to warm up: don't
start right in heavily grinding on a cold
w heel.

1/2" DRIVE AIR WRENCH

(1-88) BENCH GRINDER
Courtesy of Mac Tools

63
1:48 SHOP EQUIPMENT AND PRACTICES

PORTABLE GRINDERS
Hand held. electric and air grinders are also
available. They are made in sizes ranging
from small light-duty models with specially
shaped grinding bits to larger heavy duty ones
suitable for continuous grinding. Many port-
able grinders have accessories that can do
other jobs such as sanding, brushing, buffing.
filing. Portable grinders are used when the
work can't be brought to a bench grinder. or,
in the case of small specialty grinding jobs
when the bench grinding wheel is not the
right shape. Always use two hands on a port 01160
able grinder: never try to operate it with one 1/2" SINGLE SPEED
hand_
ELECTRIC DRILL
The same precautions that apply to bench (1-89) HAND DRILLS
grinders also apply to portable ones. In ad-
Courtesy of Mac Tools
dition. keep the electric cord or air hose free
of the grinding wheel.
Correct Use
HAND DRILLS 1. Select the ccrrect size hand drill for the
Electric and air (pneumatic) hand drills job.
(Figure 1-89) are available in 1/4", 3/8" and 2. Insert drill bits fully into the chuck and
1/2" chuck sizes. Larger sizes are made but tighten the chuck with a key.
they are not very common. Of the three drill
sizes. the quarter-inch drill has the fastest 3. Avoid excessive pressure when drilling. In
speed but the lowest torque. It is made for other words, keep twist drills sharp.
drilling holes in steel up to one-quarter inch in
diameter. Similarly. a 3/8 inch drill (medium 4. When drilling steel keep the twist drill and
speed. medium torque) is used for drilling work cool by using lubricating oil, The oil
holes up to 3/8 inch diameter. and a 1/2 inch will also aid the bit in cutting.
drill (low speed. high torque) for holes up to 5. Don't let hand drills overheat. Remember
1,2 inch. Within each electric drill chuck size. light duty drills are not intended for long
various strengths and qualities of motors are periods of continual use.
made, some for light occasional use and
others for heavy continual use. The motors 6. Air drills, like air impact wrenches, require
and switches on hand drills are either straight lubrication. See the drill maintenance in-
on-off or are variable speed (air drills are all structions or ask a journeyperson. Air
variable speed). Some drills have forward drills also have air strainers that oc-
drive only while others have reverse and for- casionally need cleaning.
ward.
7. When using an electric drill. or any elec-
tric hand tool. make sure it is properly
grounded.
8. If you have to use an electric drill a long
ways from the source of electricity, have
an extension cord of proper size to
prevent voltage drop.

3/8" AIR DRILL

64
 SHOP EQUIPMENT AND PRACTICES 1:49

A drill press (Figure 1-90) is an electric ver-

tical drill that is moved up and down a
carriage by a hand lever. The press stand has
a bed plate on which the work can be clam-
ped. Drill presses are capable of greater
drilling accuracy than hand drills because
once the work is securely clamped to the bed-
plate these can be no movement of the drill bit
in relation to the work. The hole is drilled
exactly where you want it and is perfectly
straight (or at the desired angle). Drill press
speed-torque ratios can be adjusted on most
presses by adjusting the V-belt to different
sized pulleys on the drive and driven shafts.
On large floor models having gear drive, the
gears are shifted to give speed and torque
changes. Typical uses for drill presses in a
heavy duty shop are:
Drilling steel plates or angle and chan-
nel iron when fabricating.
Drilling out broken studs or parts that
can be moved to the drill press.

Correct Use
1. Keep the bedplate clean.
2. Use a piece of wood or steel under the
work you are drilling to protect the
bedplate.
3. Use the correct drill speed.
4. Keep drill bits sharp.
5. Clamp the work securely.
6. Don't force the drill.
7. Use ample lubrication for cooling and cut-
ting.
(1-90) DRILL. PRESS
Courtesy of Malkin and 8. Remove the chuck key after removing the
Pinion Industrial Supplies drill.
FEATURES
1. Hinged Steel belt and pulley cover.
2. Ring-lock depth stop for positive depth control.
3. Sall bearing quill.
4. Quill stroke. approximately 31/2".
5. 1/2" capacity 3 jaw key-type belt tension
device for quick speed changes.
7. Machined column.
8. Slotted cast iron worktable. machined surface.
(approximately 9'/2" square).
9. Table tilts 45 degrees right and left. Pointer
and degree scale.
10. Geared table raising-lowering mechanism with
positive lock.
11. Cast base with machined top and ..r slots.

65
1:50 SHOP EQUIPMENT AND PRACTICES

HYDRAULIC POWER TOOLS

Heavy duty mechanics use the following
hydraulic tools: presses, pullers, jacks and
hoists. These tools can be either portable or
stationary and are basically used for pushing,
pulling or lifting.
PRESSES
Presses are rated according to their pushing
capacity in tons. They range from small 10-ton
bench models to large 150-ton (and higher)
standing models, Presses are a shop tool and
are not considered portable. They are made
with either the table or the adjustable
hydraulic head assembly. Note in Figure 1-91
the large pins supporting the hydraulic head
assembly and the holes in the side rack for
varying the height. A small hand winch on the
left side of the press has a cable arrangement
connected to the hydraulic head assembly to
raise and lower the head. Plates across the
top of the table are used for pressing on. The
press's hydraulic pump can be a hand type. as
shown, or be electric. depending on the size
of the press. A gauge mounted on the pump
gives the force in tons being applied.

Correct Use
1. A press is used with parts having an in-
terference fit. Always keep in mind that
presses can apply a tremendous force.
Not paying attention when pressing could
cause injury to you or to someone working
nearby and in addition break the parts
2. Press on the correct spot. e.g.. to remove
(1-91) STANDING HYDRAut.le PRESS a bearing on a shaft press on the
bearing's inner race.
Counesy of Owatonna Tool Company
3. Stand to one side white operating the
press.
4. Observe the amount of force being ap-
plied.
5. Wear a face mask in case something
should break.
6. Carefully support Ile part being disassem-
bled.
7. Know flow the pieces come apart before
attempting to apply force.
8. Make sure weight is off the cables and
support pins are fully installed.

66
 SHOP EQUIPMENT AND PRACTICES 1151

PULLERS Examples of various puller adapters in use are

shown in Figure 1-94.
There are many types of hydraulic pullers all
of which are portable. A hydraulic puller
assembly has a puller. a pump and reservoir. 0141 ).00.
and an adapter.
Hydraulic pullers are made with single and
double-acting rams and with a variety of
pulling capacities. Examples of single and
double-acting pullers are shown in Figure 1-
92.
REMOVAL OF ALLIS-CHALMERS SPROCKET

R.

INSTALLATION OF CATERPILLAR SPROCKET

(1-94) PULLERS IN USE

Courtesy of Owatonna Tool Company

DOUBLE-
ACTING

-
(1-92)
PULLERS .1.41;k

Courtesy of Owatonna Tool Company

ra&
Pumps are available in different sizes, and (1 -94) PUSHING OR INSTALLING PINS
have quick couplers on their hose ends.
Single acting pullers require pumps with
single hoses. while double-acting pullers
need pumps with two hoses and valving to
allow the oil to be pumped in either direction.
A pump and reservoir for a single acting
puller is shown in Figure 1.93.

REMOVING LARGE TAVERED REMOVING A SLEEVE

ROLLER BEARING CONE
(1-94)
The same safety rules apply to portable
pullers as to shop presses. Know how an
(1-93) PUMP AND RESERVOIR assembly comes apart before applying force,
Courtesy of Owatonna Tool Company and apply the force with caution.

67
1:52 SHOP EQUIPMENT AND PRACTICES

STEAM CLEANERS 3. Have complete circulation of the water

before turning the heat on.
There are a number of steam cleaners, each
with its own specific instructions for start and 4. Let the machine adequately cool before
stop procedures. General information on port- shutting off the circulating pump.
able steam cleaners is discussed here.
5. Clean the steam cleaner after use. Oil and
To operate, steam cleaners need the grease will soon deteriorate it.
following:
6. After cold weather operation. store the
power supply. either 120 V or 220 V machine in a warm area.
adequate water supply 7. Always make sure the machine has an
fuel oil or natural gas. depending on adequate water supply.
the machine.
Procedures for starting a steam cleaner are
usually done in this order
1. Connect the power supply.
2. Connect the water and turn on the tap.
3. Turn on the motor switch and let the
machine run until the water is fully cir-
culating, i.e., water is discharging from
the steam nozzle.
4. Turn on the fuel and ignite it. Let the
machine warm up.
5. Adjust the discharge pressure and
cleaning solution, as directed by the
machine's instructions.
Caution: Always wear a face mask, tubber
gloves. and a waterproof apron or
waterproof clothing when steam
cleaning.
For shutdown:
1. Shut off the fuel.
2. Let the machine run until it cools, then
shut off the motor switch. Note that some
machines are equipped with an automatic
shut off when the temperature drops to a
safe level.
3. Shut off the water supply and disconnect
the hose.
4. Disconnect the power supply.
To obtain maximum life l -n1 a steam cleaner
follow these few simple lutes.
1. Use only the recommended cleaning
soap.
2. Use clean fuel and service the filter
regularly.

68
 SHOP EQUIPMENT AND PRACTICES 1:53

QUESTIONS AIR, ELECTRIC AND

HYDRAULIC POWER TOOLS
1. On a bench grinder, the maximum
clearance between the wheel face and
tool rest should siot exceed:
(a) 318"
(b) 1/16"
(c) 1/4"
(d) 1/8"
2. True or False? Air impact wrenches
require lubrication.
3. When grinding, it is important to keep the
work

-
4. What is the advantage of a drill press over
a power hand drill?
5. When using impact wrenches. care must
be taken not to nuts.
6. What should you know about parts before
pressing them apart?
7. What are the three essential parts of a
hydraulic puller assembly?
8. What is the difference between a 3/8" and
a 112" power hand drill?
9. True or False? To start a steam cleaner
first ignite the fuel. then turn on the water.

69
1:54 SHOP EQUIPMENT AND PRACTICES

MEASURING TOOLS

CALIPERS AND DIVIDERS

Having no scales of theit own, calipers and
dividers (Figure 1.95) are used in conjunction
with steel rulers. The caliper or divider
measures a part and then is transferred to a
ruler to find the measurement in inches or
centimeters. Or vice versa, the caliper is set
on a ruler first and then the measurement is
"
OUTSIDE CALIPER HELD AGAINST A STEEL
transferred to the Dart. RULE TO CHECK OR SET A SIZE

Depending on the quality of the caliper, the

care with which the measurement is taken.
and the accuracy of the ruler, calipers can be
accurate to within 1/32 to 1/64 of an inch.
Common shop uses for calipers and dividers
are:
Outside Calipers: to find a shaft or pipe out- INSIDE CALIPERS HELD AGAINST A FLAT
side diameter when a rough measurement is SURFACE AND ALONG THE EDGE OF A STEEL
needed. RULE TO CHECK OR SET A SIZE
Inside Calipers: To take the inside diameter (1-96)
of a hole and compare it to the ID of a seal or
FEELER GAUGES
bearing.
Feeler gauges (Figure 1-97) are precision
Dividers: To transfer a dimension from a ruler measuring tools for checking small clearan-
to something you are making. A divider can ces. There are two common types of feeler
also be used to scribe a circle on a piece of gauges: standard and stepped.
metal.
Standard feeler gauges have several blades
r", arranged around a common pivot. The
thickness of each blade is marked in
thousandths of an inch. For example. "066" in-
dicates six-thousandths of an inch. A blade
marked "6" indicates the same thing.
Stepped feeler gauges (also referred to as a
go-no-go gauge) have blades that have two
thidknesses. The tip of the blade is one
thickness. while the rest of the blade is two-
,.....
thousandths of an inch thicker. Stepped feeler
OUTSIDE gauges are convenient for making quick, ap-
CALIPERS proximate measurements.
INSIDE
CALIPERS (1-95) DIVIDERS
For thicknesses more than about 25 thousand-
Courtesy of L W Steffen Company ths of an inch, wire feeler gauges are often
Correct Use: used. Wire feeler gauges are used. for exam-
ple, to measure spark plug gaps.
1. When using outside calipers, adjust the
legs so that they are just a little wider than
the part. Then tighten the adjusting nut
until the legs touch the part. With inside
calipers do the opposite'. start with the
legs a little shorter and adjust them out-
ward.
2. The method of transferring caliper STANDARD FEELER GAUGE STEPPED FEELER GAUGE
Measurements to a ruler are illustrated in X 2323 Courtesy of John Deere Ltd.
Figure 1-96.

70
 SHOP EQUIPMENT AND PRACTICES 1:55

Correct Use 1. Take the reading from the zero

on the bottom scale. the Vernier
1. Never wedge blades of the gauge in the scale, and read the whole in-
clearance space. If the blade being tried ches first (the 0 comes between
cannot enter the space without forcing it, 1 and 2 inches). 1.000
use a thinner blade. or adjust the
clearance to conform to the blade. 2. Read the tenth divisions next
(just over 7). .700
2. Never bend or twist the blades.
3. Read the fortieth divisions next
3. When in doubt about the thickness of a (each of the four divisions be-
blade, measure it with a micrometer. tween 7 and 8 tenths counts
4. Occasionally wipe the blades clean with .025 inch). The 0 doesn't quite
an oily cloth to remove dirt and prevent reach the first mark, and so
rusting. there is nothing here. Note
some Vernier scales will have
5. If blades on a standard feeler gauge get only two divisions between the
rough, worn, bent at the tips, cut off the tenths and each of them will
damaged portion of the blade. count for .05 inch). .000
4. Read the Vernier last (find the
VERNIER CALIPER point on the Vernier that per-
fectly lines up with a line on the
Some precision made parts require more ac- scale above. In this case it is 23.
curate measurement than standard calipers Note this Vernier goes up to 25.
can give. To measure these parts a Vernier Some will go to 50). .023
caliper (Figure 1-98) can be used; it is ac-
curate to within one thousandth (.001) inch or 5. Now add these up and the
one hundredth (.01) millimeter. Many Vernier reading is: 1.723
calipers have two sets of jaws, une for inside
and one for outside measurements. Three
types of Vernier calipers are available. A
quick change Vernier caliper has one ad-
justment: the moveable jaw is slid into contact
with the part and the measurement is read. A
master Vernier caliper has two adjustments: it
has a fine adjustment that is used after the (1-98) VERNIER CALIPER
moveable jaw has made contact. There are
also Verniers with dial indicators instead of Another example; read the Vernier scale
scales; these are easier to read than scales. at the right:
Directions follow on how to read a Vernier
scale:

To read the Vernier

scale at the right:

1. Whole inches 3.000

2. Tenths 300
3. Fortieths (2 x .025
= .050 .050

4. Vernier .007

5. Reading 3.357 inches

71.
1:56 SHOP EQUIPMENT AND PRACTICES

Try these Vernier readings: the answers are

given below.

1 2

7 ci 2 3

ill 1111103A11[411T1116 III III MP 1111000"i

0 5 10 115 20 25 0 5 10 15 20 25

3 4
4

illiti.«;10m;Iliri

Answers:

1. 1.025 3. 1.550
2. 2.759 4. 3.735

72
 SHOP EQUIPMENT AND PRACTICES 1:57

MICROMETERS Depth Micrometers: used to measure the

depth of openings or protrusions (Figure 1-
Outside Micrometers: used to accurately 102). Depth micrometers are adjusted and
measure the diameters or thicknesses of read like the other micrometers. Also. like the
parts Standard micrometers (Figure 1-99)
other micrometers. their travel is limited to
have an adjusting range of one inch Outside one inch. thus they are made with various ex-
micrometers are available in sets as shown in tensions.
Figure 1-100. The sets contain four or five
micrometers. one to measure distances be-
tween 1 and 2 inches, another to measure
distances between 2 and 3 inches, and so on
up to 5 or 6 inches. Micrometers can also be
purchased individually. A third type of
micrometer arrangement on the market is a
single micrometer that will measure distances
in a range. for example. from 0-6". In this case
the micrometer has a 6" frame with one inch SMALL INSIDE DIAMETER MICROMETER
travel on the spindle and replaceable anvils in
the increments of 1", i.e., 5". 4". 3". 2". etc.

ANVIL SPINDLE THIMBLE

,.___...-..,

DZI
BARREL RATCHET
STOP 01==
X 2311.7
FRAME 0:= t
(1-99) OUTSIDE MICROMETER
Courtesy ol John Deere Ltd
121==
X 2330 LARGE INSIDE DIAMETER MICROMETER
(1-101)
Courtesy of John Deere Ltd

M4ORL

(1-100) OUTSIDE MICROMETER SET

Courtesy 01 Mac Tools

Inside Micrometers: used to accurate'y

measure Inside diameters or distances. Inside
micrometers, like outside micrometers. also
have an adjusting range of an inch. There are
two types of inside micrometers: one for
measuring small dimensions and the other for
large dimensions. The latter has several ex- (1-102)
tensions (Figure 1-101). .( '33:, DEPTH MICROMETER
Courtesy of John Deere Ltd

73
1:58 SHOP EQUIPMENT AND PRACTICES

READING MICROMETERS Another Example (Figure 1-104):

Inside and Outside Micrometers 1. Highest tenth (1) .100

Inside and outside micrometers are read in 2. Number of marks beyond one
the same way. Refer to Figure 1-103. Note the tenth (three so 3 x .025 = .075) .075
gradations on the barrel and the thimble: each 3. Thimble reading (3) .003
mark on the datum line on the barrel
represents twenty-five thousandths (.025) of 4. Total .178
an inch, while each mark on the thimble
repreSents one thousandth (.001) of an inch.
On the datum line 4 marks make one-tenth (.1)
of an inch, since 4 x .025 = .1. Therefore, the
0. 1. 2. 3. etc., that you see on the datum line
represent tenths of an inch, e.g.. 3 is .3 of an
inch. The numbers on the thimble. 0, 5, 10,15,
20. represent thousandths of an inch, e.g., lY
is .017 of an inch.
The reading on Figure 1-103 is taken as
follows: (1-104)
1. Highest tenth visible on datum
line (2) .200
2. Number of marks beyond the 2
tenths (one so 1 x .025 = .025) .025
3. Thimble reacting (21. Note if
thimble mark doesn't line up
exactly with datum line read to
the nearest mark). .021

4. Add to get the reading. Now

depending upon the size of the
micrometer the measurement of
the part would be 1.2, 3 or 4 in-
ches plus the .246 inches. 246

DATUM LINE

(1-103) MICROMETER GRADUATIONS

COuttesY Of John Deere Lb

74
 SHOP EQUIPMENT AND PRACTICES 1:59

Try these micrometer readings; the answers

are given below.

'I 2

4
3

Answers:
1. .340 3. .132

2. .125 4. .158

75
1:60 SHOP EQUIPMENT AND PRACTICES

Depth Micrometers Try the following depth micrometer readings.

The answers are given below:
Although the basic procedure for reading a
depth micrometer is the same as for reading
inside and outside micrometers, there is a dif- 'I
ference. In the former you read on the barrel
what is covered up by the thimble. whereas in
the latter you read what is exposed on the
barrel.
Look at the depth micrometer reading in
Figure 1-105.

(1-105)

The reading is taken as follows:

1. Highest tenth covered by the
thimbles (7) .700

2. The number of marks beyond 3

the seven tenths (two since
there's only one remaining. so 2
x .025 = .050) .050

3. Thimble reading (20). .020

4. Total. .770

Answers:
1. .665 3. .968

2. .612 4. .952

76
 SHOP EQUIPMENT AND PRACTICES 1:61

Vernier Micrometers Correct Use Of Micrometers

if more accurate readings are desired, use a 1. Select the right size micrometer: Adjust
Vernier micrometer (Figure 1-106). This (1) an outside micrometer so that it is a lit-
micrometer has a Vernier scale on the barrel tle larger than the part to be measured, (2)
which divides thousandths on the thimble into an inside micrometer so that it is a little
tenths making it possible to make a smaller and (3) a depth micrometer so that
measurement to one ten-thousandth (.0001) of it is a little shallower. Adjust the thimble
an inch. Vernier micrometers are read the until contact is made. If the micrometer is
same as outside micrometers except with one equipped with a ratchet stop, turn it until
extra step: look for a mark on the Vernier at least two clicks can be heard. Some
scale that lines up with a mark on the thimble. micrometers do not have a ratchet stop;
That mark on the Vernier scale is the number for these a feel has to be developed to
of ten thousandths of an inch. know when the correct contact pressure is
made.
VERNIER SCALE THIMBLE
2. Never tighten micrometers so tight that
work cannot be drawn from them.

DATUM LINE
3. Do not slide a micrometer back and forth
excessively across the work because this
will wear away the contact surfaces and
make the micrometer inaccurate.
4. To get a more accurate reading, take the
x :::329 BARREL reading, if possible, before removing the
micrometer from the work. If this can't be
(1- 106)MICROMETER WITH VERNIER SCALE done, remove the micrometer very
Courtesy of John Deere Lid. carefully so as not to disturb the setting.

Metric Micrometers Caring For Micrometers

There are two sets of marks on the datum line 1. Avoid placing micrometers where they will
of a metric micrometer (Figure 1-107). The become heated.
marks above the line represent whole
millimeters (mm). The marks below the line 2. Check micrometers periodically with a
are half millimeters (.5 mm). The graduated master gauge or standard to ensure their
marks on the thimble represent hundredths of accuracy (Figure 1-108).
millimeters, e.g., 24 would be 24 mm. To find 3. Keep micrometers in cases or boxes to
the reading in Figure 1-107: protect them from grit and dirt.
1. Whole millimeters (4). 4.00 4. Never allow a micrometer to become rusty
2. Half millimeter (yes) .5 or dirty. Wipe them with a clean cloth
oiled with a few drops of fine machine oil.
3. Thimble reading. .33
5. Always be sure micrometer contact faces
4. Add to get the reading. 4.83 mm are clean before measuring..Never use
anything abrasive for wiping faces clean.
6. If a micrometer is dropped, don't use it
agaii , til it has been checked on a
master gauge or standard.

x f.,i,rs
(1-108)
(1-107) METRIC MICROMETER READING CHECKING MICROMETER WITH STANDARD
Courtesy of John Deere Ltd.

77
1:62 SHOP EQUIPMENT AND PRACTICES

TELESCOPING GAUGES AND DIAL INDICATORS

SMALL HOLE GAUGES
Dial indicators (Figure 1-111) measure the
For hard to reach
inside or outside movement in shafts or gears which have ad-
measurements. use standard calipers to justable end-play or back lash. e.g , the drive
measure the part and then transfer the axle ring gear. Some other uses are to ac-
measurement to a micrometer: an inside curately measure travel such as injector
micrometer for an outside caliper. and vice movement, to measure wear such as on a
versa, an outside micrometer for an inside cylinder taper, and to measure runout. They
caliper. Or. if a more accurate inside reading are available in various accuracy ranges from
is required. use a telescoping gauge or a .001" to .00005". and in various lengths of
split-ball gauge. Telescoping gauges are "T" travel measurements from 12" to .003".
shaped with spring-loaded plungers (Figure 1-
109). When the gauge is put into a hole. a lock
is loosened and the spring plunges move out
against the walls. The lock is then tightened.
tilted and carefully withdrawn. An outside
micrometer is used to take the measurement
across the plungers. Telescoping gauges are
available in different expansion ranges and
handle lengths.
The split-ball gauge (often called a small-hole
gauge Figure 1-110) is used similarity to a
telescoping gauge. The ball is inserted in the
hole, allowed to expand, then locked. An out-
side micrometer is used to take the
measurement across the ball.

(1.111) DIAL INDICATOR

1 (1-109) Courtesy of Owattona Tool Company
TELESCOPING GAUGES
Courtesy of Correct Use and Care
L or enliven company
1. Dial indicators must be securely mounted
so that the contact rod is in line with the
movement of the bearing or shaft to be
measured. Some indicators have a
magnetic base with a sliding adjustable
arm. while others have bolt on brackets.
To record full movement of the part, pry
the part in both directiens. noting the full
range of movement on the indicator dial.
(1-110) 2. Dial indicators, like micrometers, are sen-
SMALL HOLE sitive instruments and require special care
GAUGES
to keep their readings accurate. Store in-
dicators in a clean. dry place. Never drop
them. Don't allow the spring loaded
plunger to snap back when depressed as
it could damage the meter movement.
courtesy of LW Starrett Company

78
 SHOP EQUIPMENT AND PRACTICES 1:63

QUESTIONS MEASURING TOOLS 5. The reading on the illustrated three inch

to 4 inch outside micrometer is:
1. Calipers are generally used in con-
junction with a: (a) 3.157
(a) dial indicator (b) 3.467
(b) steel rule (c) 3.187
(c) inside micrometer (d) 3.012

(d) vernier caliper

2. Find the following vernier caliper
readings:

(a)

6. The reading on the illustrated three to

four inch depth micrometer is:
(b)
(a) 3.812
(b) 4 982
(c) 3.892
(d) 3.875
(0) L115f((loUlp8112011

3. Identify the numbered parts:

3.

1.13$ 1".01/
3 4310

1 IR ! 41;1
,er,
I 3 'As
, 103
Isi.tt7
1.43v44.1414 fat'
ifinS it wi
:i411$ I hinle

4, A four-inch micrometer measures objects

with a diameter:
(a) of three inches or less
(b) between three and four inches
(c) of more than four inches

79
1:64 SHOP EQUIPMENT AND PRACTICES

7. Find the following depth micrometer

readings.

(a) (b)

(c) (d)

8. Find the following metric outside

micrometer readings:

(a) (b)

(c) (d)
 SHOP EQUIPMENT AND PRACTICES 1:65

9. Find the following outside micrometer

readings:

(a) (b)

w) (d)

10. Find the following metric debt:,

micrometer readings:

(a) (b)

81
1:66 SHOP EQUIPMENT AND PRACTICES

(c) (d)

11. Inside diameters can be measured with

a:

(a) outside micrometer

(b) telescoping gauge and outside
micrometer
(c) measuring hole gauge
(d) small hole gauge and ruler
12. A telescop g gauge is used for
measuring the:
(a) circusrference of a circular piece
(b) diameter of a hole
(c) thickness of a square piece
13. True or False? Feeler gauges can
either be stepped or be the same
thickness from heel to toe.
14. A stepped feeler gauge is often called a:
(a) shim
(b) round wire gauge
tc) co-no-go gauge
15. When standard feeler gauge blades oe-
come rough or bent they should be:
(a) straightened
(b) tapped gently with a soft face ham-
.ner
(c) replaced
(d) cut off to remove the damaged por-
tion

82
 SHOP EQUIPMENT AND PRACTICES 1:67

FASTENERS 5. A bolt head is measured across the flats.

Head size determines what size wrench or
There are many types of fasteners used in the socket must be used to turn or hold the
mechanical field; a brief description of the bolt. Foi example, a 3/4 inch wrench
common ones are given in this section. (Figure 1-115) is needed to turn a 1/2 inch
bolt.
BOLTS AND CAP SCREWS

General Infer anon

I. Bolts are h ,Id in place with a mating nut,
while cap screws are generally used in
threaded holes without a nut (Figure 1-
112)
X4637

(1-115) BOLT HEAD SIZE

011 SQUARE HEAD

6.
courtesy of John Deete Ltd

Threads are measured by counting the

CAP SCREW
HEX HEAD BOLT number of threads per inch (thread pitch)
(Figure 1-116). Thread pitch on metric
(1-112) bolts is given in millimeters and is defined
Courtesy of John Deere Ltd. ri the distance from crest to crest.
2. Bolt heads are either square or hexagonal Threads are either course or fine (Figure
1-117). Course threads have deep grooves
(sixsided). Hex are most common.
and are used for applications such as at-
3. The tops of threads are called crests, and taching accessories with nuts and bolts
the bottoms roots (Figure 1-113). and threading into castings. Fine threads
are used where coarse threads are not
CREST
suitable, for example, when the parts
being fastened have thin walls and when
greater torque is required. Many intern?!
engine part. are attached with fine
threaded bolts and nuts.

X4633 ROOT
(1-113)
Courtesy of John Deere Ltd. BEEE\\\I
4. The size of a bolt is determined by the
diameter of the crest of the threads
(Figure 1-114). The lensoh of a common
bolt is determined by oftisuring from the
RULER ve
bottom of the head to the end of the (1-116) THREADS PER INCH
threads. Courtesy of John Deere Ltd.

-BOLT LENGTH -41

BOLT
SIZE

COARSE FINE
(1-114) THREAD
(1-117.) THREAD
Courtesy of John Deere Ltd. Courtesy of John Deere Ltd.

83
 1:68 SHOP EQUIPMENT AND PRACTICES

7. Bolts and screws normally have right- Note that in the past. NC standing for
hand threads: that is, they are turned to National Course, and NF for National Fint
the right or clockwise when threaded into were used to identify threads he modern
a nut or part (Figure 1-118). In a few ref : system of bolt ider lficatIon has been
cases, bolts. screws and nuts with left- used since 1948.
hand threads are needed. Turnbuckles
(Figure 1-119), for example, have one bolt 9. The Society of Automotive Engineers
with left-hand threads, and some wheel (SAE) has stablished certain standards
nuts have left-hand threads. for gradir bolts and screws based on
their maten., d treatment and on their
tensile strength or as it's sometimes
(CLOCKWE
IS
called, elastic limit. Tensile strength is the
ON)
amount of pull bolts can stand without

C14114 distorting or breaking. These standards

are being accepted as international stan-
dards by the International Standard
Organization (ISO). SAE designates
markings (slashes) to be put on bolt and
14642 screw heads to indicate grades, and all
\krefte, high-quality bolts and screws of recent
(1-118) RIGHT-HAND THREADS manufacture have them. The grade of a
Counesy of John Deere Lid.
bolt is found by counting the number of
slashes on the bolt and then adding two.
For example. if a bolt has three slashes. it
is a grade five bolt; if it has five slashes
it's a grade seven.

RIGJ"T -HAND LEFT-HAND

THREADS THREADS

(1-119)A TURNBUCKLE HAS BOTH RIGHT -HAND

AND LEFT-HAND THREADS
Courtesy of John Deere Lid

8. The modern system for identifying bolts

can be seen by :coking at the tollowing
bolt size: 1/2-20 UN C - 2A x 3. T:'d
system is explained in Figure 1-120.

Solt size (diameter)

Number of threads per inch
Stands for Unified Screw Thread Standard

Coarse
Fit symbol (1, loose fit: 2, tighter lit: 3.
tightest tit)
r Thread
Length
nto
hread (A. external bolts: S. Internal nut)

I!
1/2-20 UN C - 2A x3

(1-120) BOLT IDENTIFICATION

Courtesy of John Deere Lid

84
 SHOP EQUIPMENT AND PRACTICES 1:69

The chart in Figure 1-121 identifies the Types Of Bolts

various bolt grade:. and their charac- Common bolts: the bolts discussed so far are
teristics. Most modern manufacturers are
referred to as common bolts.
using Grade 5 or better bolts in their
products. Even if grades lower than live Plow bolts: used on plows and blades where
are used in manufacture, grade 5 or the bolts must be flush with the mold board
higher is usually specified for (Figure 1-122). They have flat tapered heads
replacement. Grade 8 and better are ex- and fit into countersunk holes. There are three
tensively used in heavy duty mechanics. types of plow bolts identified by the numbers
3. 4 and 7 (Figure 1-123).

SAE GRADE MARKINGS FOR STEEL BOLTS AND SCREWS

Tensile
Strength
Grade Marking Specification Material
4in.. psi.

SAE-Grade 0 Steel

1.1
SAE -Grade 1 Low Carbon Steel 5:5.000

SAE-Grade 2 Low Carbon Steel 69.000'

SAE-Grade 5 Medium Carbon Steel. 120.000'

Quenched and Tempered

( )

glrf SAE-Grade 7 Medium Carbon Steel.

Quenched and Tempered
133.000

SAE-Grade 8 Medium Carbon 150.000

Alloy Steel.
Quenched and Tempered

'Small Size bolls. Larger bolts may have lower values. X4646
0-121) SAE GRADE MARKINGS AND STRENGTH SPECIFICATIONS
Courtesy of John Deere Lid

(1-122) PLOW BOLTS ON DOZER BLADE (1-123)PLOW BOLTS

Courtesy oe John Deere Lie Courtesy of John Deere Lid

li
85
1:70 SHOP EQUIPMENT AND PRACTICES

Hex socket head bolts: sometimes used in Types Of Nuts

recessed (sunken) holes (Figure 1-124) or in
confined spaces where the small head size is He nuts: the most common nuts are made of
an advantage. Its head has a hexhole for a steel and are hexagonal or square. Most hex
hex (Allen) wrench. These bolts are available nuts have chamfered (beveled) corners on
in UNC and UNF. both sides (Figure 1-126) so that they can be
installed with either side down.

HEX CHAMFER
SOCKET BOTH SIDES (1-126) HEX NUT
HEAD Courtesy of John Deere Ltd
114680
(1-124) Castle nuts and slotted nuts: the top part of a
Courtesy of John Deere Ltd castle nut is smaller in diameter than the body
of the r. . (It should be noted that castle nuts
are no longer recommended for new
machinery.) A slotted nut is simply a hex nut
with slots (Figure 1-127). Both nuts are mated
with bolts having a hole drilled through the
end. When the nut is tightened a cotter pin
(Figure 1-128) is inserted through the slots
USED IN A and hole to hold the nut firmly ln place.
RECESSED HO! E Steering parts are often secured with slotted
USED IN A nuts.
X4661 CONFINED AREA

(1-124) HEX SOCKET HEAD. BOLT

Courtesy of John Deere Ltd

12-point head bolts: used when high strength

bolts with small heads are required (Figure 1-
125). They are turned by a small double hex
socket or a 12-point box-end wrench.
X4690 CASTLE NUT SLOTTED NUT
(1-127)
Courtesy of John Deere Ltd.
12-POINT HEAD BOLT

(1-125) Courtesy of John Deere Ltd

NUTS
There are literally hundreds of nuts of all
shapes and sizes. The nuts discussed here Plol BEING
PIN BENT
are the ones you are most likely to encounter. INSERTED
TO S!CURE
Nuts have three important dimensions: (1)
thickness. (2) distance across flats. and (3) in- (1-126)
side diameter (ID). Note that the ID of a nut is X4691
the same as the OD of its mating bolt. A COTTER PIN SECURES A CASTLE
OR SLOTTED NUT
Courtesy of John Deere Ltd

88
 SHOP EQUIPMENT AND PRACTICES 1:71

Self locking nuts: once tightened stay firmly vibration. Most chemical locks (Figure 1-120)
in place. There are many types of self locking are free-flowing plastic material. Wnen ap-
nuts, having many ingenious means of staying plied to threads. the chemical will fill the
tight The most common ones are called spaces between the threads and harden. i:or
prevailing torque nuts and plastic-insert nuts critical applications a primer caii be sprayed
(often referred to by their trade name Elastic on the threads to clean them and speed up the
nuts) drying time 'a the chemical lock. Chemical
locks are excellent for keeping nuts and bolts
A prevailing-torque nut has a means of grip- tight. and have the advantage that the bond
ping the mating threads. One popular can be broken. if necessary. to remove the
prevailing-torque nut (Figure 1-129) resembles nut.
a castle nut the top is split into sectors bent
inward. When the nut is threaded onto a bolt.
the sectors are forced outward and tightly grip
the bolt. Prevailing- torque nuts can be reused.
Plastic insert nuts (Figure 1-129) which are
actually a special type of prevailing-torque
nut. contain a relatively soft collar of un-
threaded material built into the head. This
collar may be a fibrous material or a plastic
such as nylon. When the nut is threaded onto
a bolt, threads are impressed into the collar.
Being elastic. the collar has a tendency to
return to its original shape when the nut is (1-130) SEALANTS AND PRIMERS FOR
removed. Although plastic insert nuts can be NUTS AND DOLTS
reused. it is usually recommended that they Gourley" of John Deere Ltd
be replaced.
Miscellaneous nuts: are illustrated in Figure
Interference nuts are similar to plastic insert 1-131.
nuts except that the top two threads are bent
in slightly in a few placeS giving an in.
terference that prevents the nut from coming
loose. Once removed these nuts are replaced

NYLONG WELD FLANGED

INSERT

PANEL ACORN SERRATED

PREVAILING TORQUE PLASTIC INSERT

LOCK NUT LOCK NUT
X4602

(1 -1 29) PREVAILING-TORQUE AND INSERT.TYPE

SELF- LOCKING NUTS SPRING
SINGLE THREAD SPEED NUT
Courtesy of John Deere Ltd

Another feature of self-locking nuts is a good

ability to seal out moisture.
Chemical lock for nuts: regular nuts can be ANCHOR
locked with i liquid lock (Loctite, for in- SPECIALTY NUT
stance) to p. went loosening, especially from X4$114 (1-131)
CoortesY of John Deere Ltd

414. !.

...
NJ' ..' 87
 ..-

1:72 SHOP EQUIPMENT AND PRACTICES

Removing Stubborn Nuts

Sometimes, due to dirt, rust, or other
corrosion. nuts are very difficult to remove.
Some shops have a power impact wrench that FROZEN
can be used to loosen tough nuts. If an impact THREADS
wrench isn't available, and the location of the
nut permits, try a striking wrench as shown in
Figure 1.132.

GAS TORCH FOR HEAT

USE CAREFULLY!

X4697

(1-134)
STUBBORN
HEAT IS OFTEN HELPFUL BUT USE IT WISELY
NUT
Courtesy of John Deere Ltd
In many cases, because of the high cost of
labor, stubborn nuts and bolts are cut off with
a cutting torch and the bolts and nuts are
replaced. If a torch isn't available stubborn
STRIKING WRENCH
nuts can be cracked off with a nut splitter
(Figure 1-135). If all else fails. use a sharp
chisel or hacksaw (Figure 1-136), but take
(1-132) USING A STRIKING WRENCH TO REMOVE care not to damage other parts.
A STUBBORN NUT
Courtesy of John Deere Ltd
Sometimes hard-to-remove nuts can be
loosened with penetrating oil (Figure 1-133) or
special liquids made for this purpose. Heat
can also be used, and is usually the quickest
(Figure 1-134). However. heat must be used
with caution in areas where it could damage
other parts.

FROZEN
THREADS X9690
(1-135) USING A NUT SPLITTER TO REMOVE
A STUBBORN NUT
PENETRATING Courtesy of John Deere LW
OIL

X968
(1-133) PENS' BATING OIL IS OFTEN HELPFUL
IN REMOVING NUTS
X4699
Courtesy of John Deem LW (1-136) USING A CHISEL OR HACKSAW ''0
REMOVE A NUT

.. Courtesy of John Deere LW

.a1MILIammr 1 .4 -0J

IM'SM1i111=112,
88
_..... .....

SHOP EQUIPMENT AND PRACTICES 1:73

RESTORING THREADS Plain washers: are steel discs with a hole

through the center (Figure 1-139). Though
Even though you try to be careful, sometimes simple parts, washers are very important in
threads may be damaged. If a replacement many applications. When used under the head
isn't available, threads may be touched up of a bolt or under a nut, a plain washer
with a rethreading tool or a thread file (thread distributes the load and thus the stress over
chaser) (Figure 1-137). an area larger than the head of the bolt or nut.
Washers also protect surfaces from being
damaged by bolt heads or nuts.
Plain washers are identified by the bolt size of
their inside diameter and by their outside
diameter. The inside diameter is a little over-
sized (about 1/32 of an inch) so that the
RETHREADING TOOL washer will slide easily over the bolt. Washers
come in various thicknesses; they are made of
mild steel for general use. and hardened steel
for locations such as under cylinder head
A47V nuts. Hardened steel washers are designated
by a part number.
THREAD FILE
(1-137) USING A RETHREADING TOOL AND Split-ring lock washers: are frequently used
THREAD RESTORER to keep nuts and bolts tight, especially when
Cou item, 01 John Deere Ito they are subject to machine vibration (Figure
Another means of cleaning or restoring bolt 1-140) When the nut or bolt is tightened, the
and stud threads is a rethreading die or die ends of the washer bite into the nut or bolt
nut available in kits of both UNC and UNF heat, and Into the fastened part. helping to
thread from 114" to 1- (Figure 1-138). Internal keep the nut or bolt from turning. Lock
holes can be recut with an internal thread washers are identified by bolt sizes except for
chaser or hand tap. although regular taps are ones under one-quarter inch which are iden-
generally used. tified by numbers.

RETHREADING
DIE
E E9:1
INTERNAL THREAD
13
CHASERS
LOCK
WASHER LOOSE TIGHT
(WASHER GRIPS)

(1.140)
HAND TAP Courtesy o$ John Deere Ltd
X11:2
'1-1381 OTHER THREAD-RESTORING TOOLS
Col.nesv of John Deere Lid

WASHERS

'4' (1-139) A FLAT STEEL WASHER

Courlesy ol John Demo Lid

89
1:74 SHOP EQUIPMENT AND PRACTICES

Tooth lock washers: are used when special NUT

holding power is required because they have
many sharp. heat-treated teeth to dig into con-
tacting surfaces (Figure 1-141). Tooth washers
are identified by bolt sizes except for ones un-
der one-quarter inch which are identified by
numbers. Often known by their trade name.
Shakeproof, they may have outside or inside
teeth. or have both outside and ins:de teeth
for extra holding ability (Figure 1-142). Cone-
shaped tooth washers are made for use with
countersunk. fiat -head screws.
(1-143)
RELATION BETWEEN A COTTER PEN.
NUT. AND BOLT
Courtesy of John Deere Ltd.

EXTERNAL INTERNAL EXTERNAL

INTFRNAL
(1-141)
X4706
TOOTHED LOCK WASHER STYLES
Courtesy of John Deere Ltd

CORRECT:
BEND PRONGS CORRECT:
BEND PRONGS

EXTERNAL TOOTHED
LOCK WASHER
_

(1-142)
X470$ CASTLE NUT SLOTTED NUT
HOW A TOOTHED LOCK WASHER GRIPS
Courtesy of John Deere Ltd. (1-144) X4709

Counes:0 of John Deere Ltd

COTTER PINS
Cotter pins hold a nut and bolt tightly together
and keep the nut from coming off. Cotter pins
are slipped between the nut slots and through
a hole in the end of the bolt (Figure 1-143).
They are made of soft metal so that the prongs
can be bent around the nut. Note that when
tightening a nut and the hole in the bolt does
not line up with the nut slots. the nut must be
tightened just enuugh so that the pin can be
inserted. Never loosen a nut to align the colter
slot unless manufacturer's instructions say so.
Some bolls may have two holes for more
precise adjustment. Cotter pin installation is
illustrated in Figures 1-144 and 1-145. (1-145)
Courtesy of John Deere Lid

90
 SHOP EQUIPMENT AdO PRACTICES 1:75

LOCKWIRES FLAT METAL LOCKS

Sometimes lock or safety wire are used to an- Another way of locking bolts or nuts to keep
chor bolts in place. The bolts have holes them from turning is with flat metal locks
drilled through their heads. The lockwire is (Figures 1-147 and 1-148). These are usually
pushed through the bolt holes (Figure 1-146) made of soft metal. although some are har-
and twisted in such a way that the wire will dened. Some have special shapes for specific
tighten if a bolt loosens. applications. Flat metal locks must be in-
stalled properly to be effective. Bend one end
Occasionally it is important to prevent of the lock sharply around the edge of the part
unauthorized tampering with critical :Figure 1-147). Bend the other end sharply
mechanisms or adjustments. In such a case a against one flat surface of the nut or cap-
seal is attached to the tockwire as it is screw head. Do not bend the lock against
twisted: the se. 'I must be broken before the more than one side of the nut.
lockwire can be removed. A special sealing
tool is t'sed t close the seal after it is in-
stalled on the lockwire. The diesel fuel in-
jection pump on a modern tractor is an exam-
ple where a lockwire and seal are used.

(1-148) FLAT METAL LOCKS HOLD FLYWHEEL

X4711 LOCKWIRE
BOLTS IN PLACE
(1-146) Courtesy of John Deere Ltd
courtesy of John Deere Ltd,

?HARP BENDS

RIGHT RIGHT WRONG

(1-147) 'low TO INSTALL FLAT METAL LOCKS
C ,nesy of Caterpillar Tractor Company

91
1:76 SHOP EQUIPMENT AND PRACTICES

KEYS born gear or other key-held part will likely

damage the part. Special pullers that fit the
One very common way of holding a gear. parts and apply force evenly are often the an-
pulley or other part to a shaft is by means of a swer. or a shop press if the parts can be taken
key (Figure 1-149). In some ways the name is to the press.
misleading because these fasteners do not
look like keys in the usual sense. Most are
simple lengths of steel cut from square or rec- STRAIGHT
tangular stock, or are round stock cut in half. SLOT
WOODRUFF
The gear or other part. and the shalt have KEY
grooves cut into them called keyways. In most
cases the key is placed into the shaft keyway.
and the gear is pressed onto the shaft over the
'4=6.
40II I
key.

SEMICIRCULAR
SLOT

KEY
INSTALLED
BETWEEN
MATING
PARTS
(1-149) A KEY AND THE KEYWAYS IN A
GEAR AND SHAFT
Courtesy M John Deere Lid X$201

Woodruff Key (1-150) HOW A WOODRUFF KEY IS USED

A semicircular key made from round stock cut Courtesy of John Deere Ltd.
in half (like a half moon) is called a Woodruff SPLINES
key. This key is t'sed to lock a shaft and gear
in one position. rather than simply to anchor a Splines are similar to keys and keyways ex-
gear onto a shaft (Figure 1-150). In some ap- cept rather than having one keyway in the
plications a straight. square key has a ten- shaft there are a number of keyways called
dency to rock because it cannot be sunk splines. The splines are cut lengthwise into
deeply enough into the shaft. In such a case a the shaft, and are evenly spaced around the
Woodruff key is used because its keyway is shaft. The part that fits on the shaft has an
much deeper than an ordinary one. Woodruff equal number of matching splines around its
keys have two dimensions, diameter (or inner diameter. The part may be a sliding fit
length) and thickness, and come in many on the shaft or a press fit. depending on its
sizes. application. Figure 1-151 shows a typical
splined shaft.
For a Woodruff key. a semicircular keyway is
cut in the shaft. The gear to be mated to the 11--............_
shaft has a straight slot cut on it (Figure 1-
150). The Woodruff key is placed in the curved
slot in the shaft and projects above the shaft
far enough to lilt the gear slot. The gear is
/8
then driven or pressers onto the shalt.
Installing and removing key-held parts such
as gears requires special care, and often
special tools. since these parts usually fit on 19
their shafts very tightly. Always follow the in- OUTPUT SHAFT ASSEMBLY
structions of the manufacturer. Using ham- 14013 3 17Dearing 1dPtStOn ring seals
mers, pry bars and chains to remove a stub- 19Snap ring
(1-151) CATERPILLAR
courtesy of Caterpillar Tractor Company

92
 SHOP EQUIPMENT AND PRACTICES 1:77

PINS Pivot pins: serve as small axles for parts to

pivot on. The pivots for governor flyweights
Some common pins are illustrated in Figure 1- are a goon; example. Pivot pins are usually
152.
headless and are drilled or grooved for cotter
pins or snap rings.
Pivot pins are often tight in their holes. Wirer
DOWEL PIN
tight-filling pins are removed, they must be
driven out with a hammer and a pin punch
that's nearly the size of the pin. Pivot pins are
often staked in place (Figure 1-154) so that
they won't fall out. A small center punch is
used for this purpose. The center punch, when
struck with a hammer. slightly (lairs the end of
OUIK-LOCK the pin pressing it firmly against the sides of
PIN the bore.

PIN

CENTER PUNCH
GROOVED
PINS XS2.11
k \
x6211 (1-154)
STAKING A PIN TO HOLD IT IN PLACE
Courtesy of John Deere Ltd
(1-152) SPRING LOCKING Taper pins: parts that must fit tightly are often
PIN fastened together with a taper pin (Figure 1-
SOME FREQUENTLY USED PINS 155). The taper on the pin helps to line up the
Courtesy of John Deere Ltd. holes in the parts being assembled. The pin is
driven into a specially reamed hole until it is
Clevis or Headed pins: the simplest pin is a fully seated. Taper pins are driven out with a
headed pin, often called a clevis pin because hammer and a punch held against the small
it is used to attach a part to a U-shaped yoke end of the pin (Figure 1-155).
known as a clevis (Figure 1.153). Headed pins .....--.1110--
are usually drilled on the end opposite the 1111%.........

head for insertion of a cotter pin, a quiklock

pin or a spring-lock pin. S
(4
PUNCH
'1,45.. SMALL
4", END OF
PIN

TAPER PIN
CLEVIS PIN
X5212 (1.153)
A CLEVIS PIN USED TO ATTACH
A TURNBUCKLE XS215 (1 DRIVING OUT A TAPER PIN
-155)
Courtesy of John Deere Ltd. A T AVER PIN AND HOW IT IS REMOVED
Courtesy of John Deere Ltd

93
1:78 SHOP EQUIPMENT AND PRACTICES

Dowel pins: are frequently used to assure that

fastened parts align exactly as they are sup-

L1 L
posed to. The dowel pins that lir.e up the TYPE 2 TYPE 3
TYPE 1
timing gear cover and gasket with the engine
cranke:ase are a good examplv) (Figure 1-156).
A dowel pin is d tiny bit larger in diameter
than the hole into which it is to go. and so it TYPE 4 TYPE 5
must be pressed or driven in. Once in place X5228
the press-fit assures that the pin will not come (1-157) TYPES OF GROOVED PINS
out. The outer end of a dowel pin projects
Courtesy of John Deere Lid.
above the surface of the part .ito which it is
pressed and males with other holes in the ad- Convenience Pins
joining parts. Dowel pins are usually per-
manent and need not be replaced unless they Several types of pins are made for quick and
are damaged. easy removal, e.g., spring locking pins and
quiklock pins.
Spring locking pins: often called a hairpin
cotter (Figure 1-158), is used when parts must
be separated for adjusting or for changing
replaceable parts. Usually a spring locking
pin is inserted into a hole drilled through a
clevis pin to hold the parts together.

DOWEL
PINS
X5276

(1.156) HOW DOWEL PINS LINE UP PARTS (1-158) TYPICAL SPRINCi LOCKING PINS
FOR EASY ASSEMBLY .Corptesy 0 John Deere Ltd.
Courtesy of John Deere Lid

Spring pins: often called roll pins, are hollow CluikLock pins: (Figure 1-159) are another
cylinders of spring steel (Figure 1-152). They handy convenience pin. A common use of
are split lengthwise and beveled at each end these pins is to fasten removeable at-
for easy starting. They are used in areas tachments to a machine such as three-point
where loads are not too great. Spring pins ure hitch parts to a loader-backhoe.
made slightly oversize so that when they are
driven or pressed into place. they are com- Ouik-lock pins have a split steel ring. The
ends of the ring fit into two holes drilled in dif-
pressed it is this tension that holds the parts
ferent planes in the pin head. Once the pin is
in place. To remove a spring pin. drive it out of
its hole with a punch lust a little smaller in in place, the steel ring is rotated down and
diameter than the hole. around the end of the clevis pin (Figure 1-
159). The difference in the two planes of the
Grooved pins: are solid, having slots or ring ends develops an over-center spring ac-
grooves cut along all or part of their length tion which holds the ring firmly around the
(Figure 1-157). Their holding power comes clevis pin holding the quik-lock pin in place.
from a tendency to expand when driven into Some quik-lock pins have a short chain which
place. Grooved pins come in standard types. can be fastened to a convenient nearby part
In the past the type designations were letters to keep the pin from getting lost.
A, B. C. etc. but now numbers are used: Type
1. Type 2. etc.

94
 UM

SHOP EQUIPMENT AND PRACTICES 1:79

rivet (the shank) with a ball peen hammer or a

riveting machine. When hammering the
PIN second head, the first rivet head must be
pressed against something solid, otherwise
the second head will not be formed properly.

BALL PEEN
HAMMER

001K-LOCK RING SNAPS

PIN INSTALLED DOWN OVER END
X5223
FORMED
(1-159) OUiK-LOCK PIN PROPERLY INSTALLED SHANK
Courtesy of John Deere Ltd
RIVET
Shear pins: sometimes it is important that a
pin be lust strong enough to carry the normal
load imposed upon parts. Such a pin is called
a shear pin. The pin is made of a softer metal SOLID SUPPORT
than the shaft and part it aligns. It acts as a
X5230
safety device and wiii shear. or be cut off,
when the parts are overloaded, preventing (1-161) PEENING THE SECOND HEAD OF A RIVET
more serious damage to the machine. A shear Courtesy of John Deere Ltd
pin is used for example on an outboard motor
propeller.
Mind rivets: are intended for light duty use
RIVETS where the joint is accessible from only one
side (the other side is blind). One common
Rivets are soft metal pins with a head on one type (Figure 1-162) known as a pop rivet
end Some common rivets are shown u Figure requires a special tool to install it. After the
1-160. rivet Is inserted. the tool pulls a stem with a
bulb on the end up through the hollow center.

9 9 V thif IRON RIVETS

The bulb causes the blind end of the rivet to
flair, thus securing the rivet. The stem is then
broken off.

SPECIAL
TOOL

(:::/ ti RIVET
TUBULAR. SPLIT AND COMPRESSION RIVETS

BLIND RIVETS
X5228
(1-160) RIVETS
Courtesy of John Deere Ltd

Common iron rivets are used primarily to hold

two or more Hat. parallel parts together. The X5232 (1-162) INSTALLING A POP RIVET
parts are drilled or punched, a rivet is inserted
into t: e matching holes (Figure 1-161), and a Courtesy of John Deere Lid
second head is formed on the other end of the

it
1
"95
..,,...

1:80 SHOP EQUIPMENT AND PRACTICES

Another type of blind rivet also has a stem, but

instead of pulling on it. the stem is driven into
the rivet (Figure 1-163). The stem flares the
lower end of the rivet to hold it firmly in place.

SHANK

RIVET

STEM FLARES TO
HOLD RIVET

Az.f..14

(1-163) TYPE OF BLIND RIVET

Counesy of John Deem Ltd

96
 SHOP EQUIPMENT AND PRACTICES 1:81

QUESTIONS FASTENERS 9. Hex head. phillips, and alien are terms

used to describe different types of:
1. Bolt head markings are usually:
(a) screw threads
(a) slash marks
(b) studs
(b) letters
(c) screws
(c) dots
(d) numbers 10. A castle nut requires:
2. How is the length of a bolt determined? (a) a lockwasher
(b) a jamnut
3. Thread size refers to the:
(c) a flatwasher
(a) number of threads per inch
(d) a cotter pin
(b) length of the threaded part
11. True or False? The cap screw has fine
(c) diameter of the bolt or screw thread on one end and Coarse thread on
4. A threaded pitch refers to the: the other.
(a) diameter of the bolt or screw 12. To determine the wrench size a bolt is
measured:
(b) number of threads per inch
(c) length of the threaded part (a) across the shank
(b) across the points on the head
5. The marking on the head of the
illustrated bolt indicates the (c) across the flats on the head
of the bolt:
(a) size
(b) length
(c) the grade
(d) thread type

6. What grade is the bolt in question 5?

7. The screw pitch gauge is used to deter-
mine:

(a) the depth of the thread in inches

(b) the length of the thread in inches
(c) the number of threads per inch
(d) the lead of the thread per inch
8. Hex. square. and castle are terms used to
refer to different types of.
(a) screws
(b) bolts
(c) nuts

97
1:82 SHOP EQUIPMENT AND PRACTICES

13. Match the numbered illustrations to their

name:

9 101

hex head bolt 14. Name three ways of removing stubborn

plow bolt nuts.

hex socket head 15. What is the advantage of a Woodruff key

over a straight key?
12point head boil
hex nut 16. True or False? When a bolt has been
tightened and the bolt hole does not
castle nut quite line up with the (kit slots, slightly
lock washer loosen the nut so that you can insert the
lock nut cotter pin.
flat washer 17. True or False? To properly secure a nut
with a flat metal lock, try to bend the lock
slotted nut
against two fiats of the nut head.

98
 SHOP EQUIPMENT AND PRACTICES 1:83

HOSES, PIPES, TUBES, Hose Construction

FITTINGS AND ADAPTERS
Flexible hose has three basic parts: an inner
HO SE tube, reinforcement layers, and an outer cover
(Figure 1-165). The inner tube is an oil
Flexible hoses with reusable Sittings are one resistant synthetic rubber layer. it must be
of the most important parts that require smooth, flexible, and able to resist heat, and
replacement on modorn machinery. Hoses corrosion. The reinforcement layers vary with
and fittings are used lor diesel fuel, tube oil. the type of hose and pressure requirement of
air and water lines. They are also used on the system. The layers (or plies) are con-
most hydraulic systems. having the ad- structed of natural or synthetic fibers. braided
vantages that they allow for motion. absorb wire, or a combination of these. The outer
vibration and noise, withstand pressure cover protects the reinforcement layers. A
surges and are easy to route and connect. special rubber is used for the outer cover that
resists abrasion and exposure to weather, oil.
Hoses are available in tow, medium. high and and dirt.
very high pressure ratings. Hose sizes and
pressure ratings are generally stamped on the
outer cover Another way of identify;ng hose is OUTER COVER
by its dash number. The dash number
represents the triside diameter of the hose in
sixteenths of an inch. For example. a half inch REINFORCEMENT
hose has a dash number of 8. meaning an in- LAYERS
side diameter of 8/16ths or 1/2 inch,
INNER TUBE
Some hoses on machines are replaced by cut-
ting bulk hose to the required length and then
attaching to it either the old fittings or new
ones. Others are assembled hoses with crim-
ped on fitting:, and must be ordered from the (1 -165)
manufacturer. FLEXIBLE HOSE CONSTRUCTION
Figure 1-164 shows a cutaway view of a Courtesy of Jonn Deere Ltd
flexible hose with typical screw-type
replaceable fittings. Coarse. left-hand threads Types Of Hose
on the inside of the socket (2) grip the hose's
outer cover as the hose is turned into the There are four common types of hoses. each
socket. A recess in the end of the socket per- differing in the strength of their wall con-
mits the insertion of the tapered end of the struction (Figure 1-166). From a repairman's
nipple into the socket so that the fine threads point of view. the important point to note
on the nipple can engage with the matching about differnt types of hose is that each hose
threads in the end of the socket. As the nipple is constructed to withstand the conditions and
is threaded into the socket, it forcefully pressures of a certain system. Therefore.
squeezes the inner liner and other layers of when a hose is replaced, the new one must be
the hose out against the socket. Once assem- exactly the same type and size as the one
removed.
bled properly, the fitting requires no
lightening or adjusting.

1 2

1Nipple 2Socket 3Hose 4Nipple

(1-164 CUTAWAY VIEW OF A TYPICAL FLEXIBLE HOSE Courtesy of Ts/ex. Division of

AND REUSABLE FITTINGS General Motors Corporation
 1

1:84 SHOP EQUIPMENT AMC PRACTICES

COVER-.
COVER- RUBBER DR COTTON
-FULMER OR COTTON
SINGLE WIRE BRAID
FABRIC BRAID REINFORCEMENT
REINFORCEMENT
COTTON
INNER BRAID
SYNTHETIC RUBBER
INNER TUBE SYNTHETIC RUBBER
INNER TUBE

IFABRIC BRAID HOSE! SINGLE WIRE BRAID HOSE

(For Lower Pressures) (Medium Pressure)
............________.RUBBER COVER

.,1r.,..7.11vRUBBER COVED. .....1N.WLTIPLE

........----
SPIRAL
WIPE WRAP
REINFORCEMENT
BRAID
co ..
MULTIPLE WIRE BRAID COTTON BRAID
REINFORCEMENT
SYNTHETIC RUBBER
SYNTHETIC RUBBER INNER TUBE
INNER TUBE

(DOUBLE WIRE BRAID HMI 'SPIRAL WIRE HoSil

(High Pressure) (Very High Pressure)
(1.166) THE FOUR TYPES OF HOSES
Courtesy of John Deere Ltd.

1. Fabric Braid Hose

(a) Reinforcement. Woven fiber rein- Use: Lines for Petro'eum-base hydraulic
forced with spiral wire to prevent oils. gasoline or fuel oil. In suction
collapse. lines or in low-pressure return fines.
(b) Reinforcement. One-fiber braid. Use: Hydraulic oil return lines only. or
general-purpose fuel oil. gasoline.
water. anti-freeze mixtures, air and
other chemicals.
(c) Reinforcement Two fiber braids. Use: Hydraulic oil return lines only. or
general purpose fuel oil, gasoline.
water, anti-freeze mixtures. air. and
other chemicals.
te: Fabric braid. tow-pressure hose is not recommended for hydraulic pressure lines

100
 SHOP EQUIPMENT AND PRACTICES 1:86

2. Single Wire Braid Hose

Seinforcement: one braid or high tensile Use Hydraulic oil lines. fuel oil. gasoline or
steel wire. water lines.
3. Double Wire Braid Hose
Reinforcement: Two or more braids of Use: High pressure hydraulic oil lines. fuel
high tensile steel wire. oil. gasoline or water lines.
Note'. Both single and double wire braid hose are widely used in the heavy duty mechanics field.
4. Spiral Wire Hose
Reinforcement. Multiple spiral of high ten- Use: Very high pressure hydraulic oil lines
site steel wire and one fiber braid. or fuel oil lines.
Note: Spiral wire hose is recommended for systems having high surge peaks. Surges can cause
weak spots in wire braid hose. bu; spiral wire reinforced hose does not weaken under high
surges.

Selecting Hose
The following chart will help you to select the proper hose for any pressure application. Find the size
of the hose you need and read across. to the system working pressure nearest your application. If
you find it In column 1. use a single wire braid hose, if in column 2, use a double wire braid hose; or
in column 3. a spiral wire hose.

SELECTING HOSE FOR VARIOUS PRESSURES'

--
Hose
Size in
Inches
,4,,
3/.0 0
ih
1 Use SINGLE WIRE BRAID
Hose II System Working
Pressure Equals ...

3000 psi
2250 psi
2000 psi
-
2. Use DOUBLE WIRE BRAID
Hose If System Working
Pressure Equals ...

5000 psi
4000 psi
3500 psi
3. Use SPIRAL WIRE Hose
If System Working
Pressure Equals .. -
A

5000 psi
4000 psi
1/2"
34"
1750 psi 2750 psi -.-
1500 psi 2250 psi 3000 psi
1" 800 psi 1875 psi 3000 psi
11/2" 600 psi 1625 psi 3000 psi
1 1/2" 500 psi 1250 psi 3000 psi
2" 350 psi 1125 psi 2500 psi

Note how larger hoses are recommended for lower pressures rather than Smaller
ones of the same construction.

101
 1:86 SHOP EQUIPMENT AND PRACTICES

Hose Fittings
Fittings are couplers at the ends of hoses that
connect the hose to a component or to
another line. There are male and female fit-
tings. male fittings have a socket and a nipple
with a hex nut (Figure 1-167), while female Ft-
tings have a socket and a nipple with a swivel
nut (Figure 1-168). Female fittings are
sometimes called swivel ends. Hose fittings
have several methods of sealing the threaded
end (Figure 1-169).
$

SOCKET HEX NUT

'tam SW. 611!111

MALE FITTING FEMALE FITTING
4°1"111111111111
:j"Imr (1-168)
as mrd.WPia' "a I

I Courtesy of John Deere Ltd.

NIPPLE
(1-167) MALE FITTING
Courtesy 01 Jahn Devi. Ltd
0 THREAD SEAL Some fittings (called permanent) are thrown
METAL-TO-METAL away when the hose is replaced, where as
(NATIONAL PIPE others (reusable) are saved from damaged
THREAD) hose and attached to a new hose cut from
o DRY SEAL TO
stock. Permanent hose fittings are crimped or
swedged onto the hose (Figure 1-170).
Reusable fittings are either pushed, screwed,
30 DEGREE or clamped onto the hose. Make-up
CONE SEAT
procedures for reusable fittings are illustrated
©
FLARE SEAL .f
in Figure 1-171.
.
TO CONE SEAT There are low pressure, medium-pressure and
(ALSO AVAILABLE high-pressure fittings. High-pressure fittings
IN FEMALE SIAM/El are usually marked with a notch. whereas
medium and low pressure fittings have no
notch (Figure 1-172). Never intermix a male
J1 C FLARE SEAL TO 37 DEGREE and female coupler of different pressure
CONE SEAT rating.
Besides identifying high pressure fillings. the
S A E FLARE SEAL TO 45 DEGREE notch markings also act as a gauge for the
length of the outer cover that must be
0 CONE SEAT
,z4p;
removed (skived) from the hose so that the
socket will fit. Note, however, that hose is
O -RING available called no-skive hose that does not
SEAL
require the outer layer be removed for the
socket to fit. Be sure when using noskive
0 r-
'::7)
* hose that you match it with the right size fit-
ting.
SPLIT FLANGE
0-RING SEAL

?,
(1 -169)
FIVE MAJOR WAYS OF SEALING HOSE FITTINGS
Courtesy 0 John Deere Ltd

102
 SHOP EQUIPMENT AND PRACTICES 1:87
NOTCH
SOCKET HEX NUT

A3407
PERMANENT REUSABLE NIPPLE MEDIUM PRESSURE FITTING HIGH PRESSURE FITTING
(1 -170) (1-172) HOSE FITTINGS

/1114111111A.

SOCKET AND NIPPLE

SOCKET AND NIPPLE (High Pressure Notch
SOCKETLESS
(Medium Pressure.
(Low Pressure) on Socket)
Single Wire Braid Hose) (Multiple Wire Braid Hose)
ASSEMBLY

I Cut hose to length with

lone tooth hacksaw or cut-off 1 Cut hose to length To
wheel Skive if required (See stop off protective cover til
at right) Screw hose coun necessary) cut around hose
terclockwise into socket un down to me.al wire rein-
Cut hoSe to length with a til it bottoms Back off %- forcement. then cut cover
sharp knife Oil onside of turn lengthwise and pull off
hoSe and nipple liberally cover Clean wire with wore
a. brush or soft were wheel
Avoid flaring or Waying wort
reinTorcentai

2 For male ends. If

2 Push hose on lilting until required insert assembly
tool mandrel (01 correct 2 Screw hose coun-
it bottoms underneath terclockwise into socket un
protective cap size) into nipple and oil nip-
ple threads. assembly tool. id et bottoms
DISASSEMBLY 7 and inside of hose If a man reA_
drel is not available. a drill
bit of the size that lots into ,
the letting works well InSert
t the bit shank. first through
the kiting. then into the
e
hose Doing this will prey rit i,f=c,
;-.1
the inner toner of the hose
from bunching up snside of
I Slit hose from protective the fitting and causing an 3 Oil nipple threads and in-
cap to end a nipple unwanted check value side of hose liberally Use
grease for target sizes

3 For ma e ends. screw nip-

2 Bend hose and snap it oft ple clockwise onto socket
until snug against socket
4 Screw nipple clockwise
*are a quick pull into socket Leave lit in to
%. In clearance

(1-171)
Courtesy of John Deem Lid
INSTALLING REUSABLE HOSE
FITTINGS 4 For tomato ends. tighten Leave ' in to ' i. on
nipple and Out on assembly clearance between nut and
tool d required Screw nip. socket
Pie Clockwise _socket

03
1:88 SHOP EQUIPMENT AND PRACTICES

Installation of Hose Hose Adapters

See Block 3. Hydraulics. See S.A.E. Flared Tube Fittings a few pages
on.
Good Practices When Installing Fittings
Failure Of Hose Fittings
1. Be sure the working pressure rating of
the fitting corresponds to that of the Leakage is the most common failure of hose
hose, Also. the make of the hose and fit- fittings: it is usually the result of stripped
tings should be the same. threads. damaged 0-rings. or mismatched
seals. Failures can be caused by:
2. Be sure seal replacements match the fit-
ting. improperly assembling fittings in hose
ends.
3. Use flared adapters or elbow hose fit-
tings where possible instead of pipe overtightening swivel nuts while
adapters. leaving pipe threads loose
the fitting being hit during operation.
4. Improve the line routing by use of 45
degree and 90 degree adapters or using too much sealing compound
elbows. (pipe dope) which restricts the flow.
Attach male ends of hose assemblies using a low-pressure socket in a high-
5.
before female ends so the hose does not pressure system.
twist. mismatching fittings and hoses.
6. Tighten swivel nuts only until snug. Do
not oiertighten them. Swivel nuts, unlike
p.pe threads, don't require compression
of the threads to seal. U a rule. tighten
the fitting until finger tight, then use
wrenches to tignteq the lilting two extra
flats. If leakage occurs after operation.
tighten one extra flat.
7. Tighten only the nipple hex nut and not
the socket.
8. Use open-end wrenches for assembly: do
not use pipe wrenches.
9. Use two wrenches where necessary to
prevent twisting of hoses. one wrench to
hold the hose and one to tighten the
swivel nut.
10 Tighten the fitting on the Fuse. not the
hose on the fitting.
tt Use pipe sealing compound on male
threads only and make sure the com-
pound is compatible with We hydraulic
oil. Do not use sealing compound on
swivel nuts.

104
 SHOP EQUIPMENT AND PRACTICES 1:89

PIPES AND TUBES Strength and Line Size

Pipes and tubes are referred to as rigid lines Strength and line size are two other important
(Figure 1-173) The choice between pipe or characteristics of pipes and tubes. Wall
tub. 3 depends on the system's pressure and thickness determines the strength of the line.
flow The, advantages of tubing include easier the thicker the wall, the stronger the line. The
bending and flaring. fewer fittings, nicer ap- inner diameter of the line determines its size.
pearance, better capacity for reuse, and kss Note the importance of line size. too small a
leakage However, pipe is cheaper and will line would cause pressure drops. restrict flow.
carry larger volumes under higher pressures. and create heat (i.e., power loss). A line too
Pipe is used where straight-line hook.ips can- large is cumbersome and costly.
not be avoided and where more permanent in-
stallations are needed. The sizes of tubes are given as fractions of an
inch or as dash numbers representing six-
Materials teenths of an inch. These sizes give the
nominal dimensions of the tube's outside
Pipes for hydraulic lines should be made of diameter.
seamless cold-drawn mild steel. Galvanized
pipe should not be used because the zinc Pipe sizes are given by the nominal dimen-
coating may flake or scale and damage the sions of their inside diameters, and by a wall
hydraulic valves and pumps. Tubing can be thickness rating Wall thickness ratings are
made from a variety of materials: represented by schedules:

Copper limited to low pressure hydraulic Schedules 40: standard pipe

systems with little vibration. Copper tends to 80: extra heavy pipet
become brittle when flared and subjected to 160: double extra heavy
high heat.
Aluminum has good flaring and bending
characteristics, but is limited to low pressure Failures
use.
If pipes and tubes are of good quality and are
Plastic used in low pressure hydraulic ap- well maintained. failures should rarely occur.
plications only. Maintenance on pipes and tubes includes
checking for:
Steel has become the accepted standard
in hydraulics where high pressures are en- loose clamps that cause vibrations.
countered There are two types of steel lines that may have been accidentally
tubing' seamless and electric welded. hit. bent. or pinched during operation.
wet spots that could mean a pin-hole
leak in the line.

Pipe Fittings
Pipe is normally connected by taper threading
its outside diameter with a die and then
screwing it into a taped hole. Sealing com-
(1-173) TUBING pound is applied when the pipe and taped
Courtesy 01 John Deere Ltd hole do not have dryseal or precision cut
threads.
Besides sealing compounds. pipe threads and
connections can also be sealed by using fit-
tings with pipe lock nuts. These fittings have a
free nut with a Teflon seal ring. When
positioned and tightened. the nut forms the
seal and lock the fitting in position. Pipe fit-
tings are available in many differnt styles.
(1.173) PIPE both male and female. They are constructed
Courtesy of John Deere Ltd of three types of material:

105
1:90 SHOP EQUIPMENT AND PRACTICES

1. Brass in small sizes for low and medium

pressures.
2. Cast iron In large sizes for low and
medium pressures (Figure 1-174).
3. Steel in varying sizes for high pressure
hydraulic applications. Note that for high
pressures. i.e.. pressures above 1000 psi.
fittings must be welded.
IRON PIPE THREAD FITTINGS
Made with tapered pipe threads and machined to fit perfectly in conformity with
the modified standards of the Society of Automotive Engineers. Only the finest
brass castings and rods are used.

. ,

( )1 71 04=1 k14,' qil

_
I
11 1 I

1-100 Elbow 11-101 Tee 5.10$ Coupling 1.11$ Lone Nipple

-- Pros Thread Pare Thread

_ __ ___ 1,8_ Pure Thread Pee Thread

1/8
Length

1-1/2
, _. 1 8 18
_ _ ___

_
14 I4 I/4 I;4 1.1/2
38 38 3:8 3/8 1 1 /2
1 2 1 2 1 2 1/2 1.1/2
1 /8 2

- 1,'4

(*)
2
_- ._
i. i ---2--

--
__2.1/2
--- _
1

110 1
___
1,1
1/8
- - --__ _ _
2

2.1/2
-
,

_
4
. -
3/8 2.1/2
11-104 Union 1.109 Plug II. t 10 Bushing 1/2 2.1/2
_

Pope TWA Pare Thread Pipe Thread 1 /8 3

.__
_
18 18 1'4x1 8 __ ..__
3/8
114
_ 3

1 4 1 4 3 8x1 4 3
38 38 3 8)08
_ __._ _ _
1/2 3

12 12 1 2x3'8 1/8 34/2

1 2)11 4 1/4 -----1----
3.1/2
__ ._ . _

_.
3 03 '8
3. 4x 1 '2
3/8
____
1 /2
---.
3.1/2_--
3.1 12

, 1 [ . AL ,o,,;,, ,1 ,1,11, It

o
1

1 .124
43°
,,,,.. ",s 1.112 1.116 1.121
1.122 Hex Nipple Elbow - Close Nipple Street Elbow Square Need Plug

_
_ --.
Pipe Thread
_ Pipe Thread Pipe Thread Pups Thread
...--..
Pipe Thread

1 8x1 8
1;4 al /4
1/8
1/4
__ 1/8 _..._ _
1/4
-'Y" 1.8
1r 4
__ --..--1/8
1/4
-- -
3'8x3 8 3r9 3.8 318
i2
---1 '2
1 /2 1 '2

Courtesy of E Edelman and Co

(1.174)

106
 SHOP EQUIPMENT AND PRACTICES 1:91

Good Practices For Installing Pipes and Pipe Tube Fittings

Couplers
Fittings connect tubes to components: they
Installing Pipes must form a seal without the tube having to
turn. Tubing. unlike pipe. is too thin to be
1 Always replace pipes with ones of iden- threaded, so another method must be used to
tical size, shape and material Do not attach the tube to the fitting. Although there
make substitutions. are many types of tube fittings available, they
can be classified into two basic groups: flared
2. Where possible. avoid straight-line fittings and compression fittings.
hookups, especially for short distances.
because they do not allow for enough ex- Flared fittings: are used with the thin-walled
pansion or contraction during heat and tubing that is easily flared. Sealing is by
pressure changes. metal-to-metal contact. The flared end of the
tube is squeezed between the mating surfaces
3. When installing long pipe lines, use as the fitting is firmly tightened to another
brackets and clamps to reduce strain and
connection. There are two common types of
fatigue on the pipe. Pipe-fitted com- flared fittings used in the mechanical trade:
ponents or heavy fittings should also be inverted flare tube fittings and $AE flare tube
bolted down to eliminate stress on the fittings.
Pipe.
4. Use bulkhead fittings where lines pass
through a wall or beam. They not only
provide ease of dismantling, but also give
added support.
5. Replacement pipe must be clear. and free
from rust and scale-

Installing Pipe Fittings

1. When cutting pipe threads. use sharp
standard pipe taps or dies. and a good
cutting oil. These threads will keep
leakage to a minimum.
2. Remove burrs from both the inside (with a
reamer) and outside of the pipe end.
3. Clean all foreign matter from pipes and fit-
tings.
4. Use union connectors at various points to
aid later removals,
5. When using pipe sealing compound.
cover only two-thirds of the threaded male
end. Never apply pipe compound to
female threads. Make certain the pipe
compound is compatible with the
hydraulic Iluid. Never use shellac as a
sealer.

107
1:92 SHOP EQUIPMENT AND PRACTICES

Inverted flared tube fittings: are illustrated in

Figure 1-175. Note especially the mate elbow
and straight male connector. In making a con-
nection the nut Is first placed over the tubing
with countersunk ends towards the tubing
end. The tubing is then flared, and the nut
when tightened against the flare provides a
seal. Note in Figure 1.175 that when iden-
tifying an inverted flared fitting, the tube size
is given first. then the pipe thread size of the
fitting.

INVERTED
FLARED TUBE
FITTINGS
ASSEMBLY OF B-24 CONNECTOR CUT-AWAY OF 8.24 CONNECTOR
COMPLETE WITH B21 NUT COMPLETE WITH B21 NUT
,-

mo
M1,,,,,
11
., aztit WI 'qlfl ,

iiiiii i 0! ' --'

r c..
(
i 1 CIP001 ?....... !
!
1,w!.,____
1.21 Nut 1.22 Mate Elbow 8 -23 Union 1.24 Note Connector 11-28 45° Elbow
Tube Tube Poe Tube Tube Poe Tubs 1 Pipe
She Site Thread She the Thread She 11 Thread

3,16 3/16 I 1/8 3/16 3/16 1/8 3/16 1/8

1.'4 1.'4
_.---.___
1/8 1/4 1/4 1,8 1/4 1/8

5;16 1'4 14 5/1r. 1/4 1/4 06 1/8

38 5,16 10 3/8 5,'I6 1/8 3/8 1/4

---___
1 2
___ .
5,'16
_
3,6
_.
1;4
_._____
1/4
__ 5/16
3/8
1/4

1/4

I 2 3;8

(1-175) Courtesy of E Edelman and Co

108
 SHOP EQUIPMENT AND PRACTICES 1:93

SAE tube fittings (Figure 1-176): are the most SAE flaiod tube fittings are manufactured to
common fittings found on heavy duty equip- the exact specifications of the Society of
ment, They are used not only to connect Automotive Engineers. In making a con-
tubing but also as adapters for replaceable nection with these fittings, first place the nut
hose fittings. For example. the Bob male con- over the tubing end with the large threaded
nector is the adapter fitting used with a hole towards the tube end. then flare the end
female swivel fitting on a hose end. Figure 1- of the tubing. The fitting has a tapered seal
177 illustrates places where adapters (i.e.. and the tubing is held between the tapered in-
SAE flared tube fittings) are used. When or- side of the nut and the beveled face 'A the fit-
dering SAE flared tube fittings, as with in- ting. This makes a very tight seal and secure
verted fittings. the tube size is given first. then joint that will withstand great pressure.
the pipe size.

.11.01.111111-
'4111Lauglemm *Aar'
ASSEMBLY OF B-42 UNION CUT-AWAY ASSEMBLY OF
WITH B-41 NUTS B-48 CONNECTOR WITH B-41 NUT

S.A.E. FLARED TUBE FITTINGS

.1- '

am.
, I

+) IR 110. 1 i;H- IHrT

- ____.

._
1-41 Nut

Um Site
iiiT_ _ _ .
1/4
5.16
_
3-4 IS
Short Nut
Tube S3I0

3116
1

$'16
4
_
_ _ _ --
8.42 Union

Tube Site

3/16
I '4
5/16
_.
1.44 Too

Tuba Site

.-._ _ -

__
_-
3/16
14
5/16
_ _

_-
Tube She
3/16
1 :4
14
11.4$
Male Connector

.
SeieeT:Iseed
18
18
1 4
3' 16
14
i4
B-49
Melo Elbow

Tube Ski I ripe "reed

18
18
1 4

38 38 3/8 3/8 5/16 18 5 16 18

1.2
_
1.2 1/2 -172--- 5 /16 14 5.16 i 4

5/8
......._______,. _ _
S'8 .518
... ___ . _ _ _. __
5/8 _ _ 3/8
__.. _ . _
1 4 38 1 4

3 l4 3 '4 34 3/4 3/8 11 .31 , 1 8

---3/8 3/8 38 38
i /2-
1 .1
----i/8
._---- -
1/2
---1 /2
1/2
- 38
12

(1. 176)
./8 1 1/2 5/1-1--- 1 2
3/4 1/2 3/4-- 12

Courtesy of E Edelman and Co

109
1:84 SHOP EQUIPMENT AND PRACTICES

JOIN HOSE TO COMPONENT

CONNECT LINES

REDUCER (1.177)
BULKHEAD COUPLER
FOUR USES OF HOSE FITTINGS counesy of John Deere lid
Compression fittings: the advantage of com- seat. To assemble these fittings insert the
pression fittings is that a flaring tool is not copper tubing through the nut into the body of
needed to install them. There are two common the fitting as ,ar as the shoulder of the body
types of compression fittings used in the permits. Tighten the nut to the body and the
mechanical trades. double compression fit- assembly is complete The sleeve end of the
tings and solderless compression fittings. nut is wedged by the tapered seat of the body
and bites into the copper tubing to form a
Double compression fittings (Figure 1-178). liquid tight seal. Since it is crimped to the
consist of a nut with an integral sleeve and a tube. the fitting also provides a swivel for
body internally threaded with a machined removing the tube.

DOUBLE
COMPRESSION

B-12 CONNECTOR FITTINGS CUT-AWAY OF 8 -12 CONNECTOR

COMPLETE WITH B-11 NUT WITH B-11 NUT ASSEMBLY
DOUBLE COMPRESSION FITTINGS

11-11 NO 1-12 Mole Connecter 5-15 Mole Elbow

Tube Pipe Tube Apt
Site
Tube Sue Mod Site Thteed

1/8 1/8 1/8 1/8 1/8

3116 3/16 1/13 3/16 1/8

1 '4 3/16 1/4 1/4 1/8

5.16 1/4 1/0 5/16 1/8

3/8 5/16 1/8 3/8 1/4

1/2 3/8 1/4 1/2 3/8

1/2 3/8

(1-178) Counes, of E Edelman and Co

110
 SHOP EQUIPM ENT AND PRACTICES 1:95

Common solderless compression fittings: are Solderless compression fittings consist of a

shown in Figure 1-179 They are used on low nut. a double tapered sleeve. and a body. To
pressure circuits such as gasoline supply make a connection. place the nut and sleeve
lines They should not be used on brake tines over the tubing and insert the tube into the
body of the fitting as tar as possible. The
wedging action 01 the sleeve between the
body and the nut makes a tight joint.

CUT-AWAY VIEW OF ASSEMBLY OF B-62 FITTING

8-68 CONNECTOR

SOLDERLESS COMPRESSION FITTINGS

1.10 Sleeve B..' Nut 1.62 %den 1.64 Tee 11-11 Elbow

Tube Sue Tube S.te Tube Site Tube She Tube Site

1,8 18 18 1/8 1/8

3116 3 16 3'16 3/16 3/16
-
-14 14 Ti 4 1/4 1/4
S 16 5,16 S 16 5.16 5/16
38 38 38 3'6 3/8
7 16 7 16 .
12 1/2 1/2
12 12 58
58 S8 34 3/4 3/4
34 34
(1.179)

Courtesy of E Edelman and Co

Iii Mole
Connector 1.19 Male Elbow

Tube Poe Tube Pspe

Sue vitae Sue Tweed

18 1 13 18 18
3 16 1 8 316 18
14 1 8 14 18
14 1 4 14 14
5 16 18 $16 18
5 16 1 4 5 16 14
38 1 38 i4
38 1 8 38 18
38 3B 38 38
7 16 1 4 12 3.1
12 38 1 1/2
12 12 S8 1/2
/2-
58 3 '4 1,2
34 2

111
 111F,

1:96 SHOP EQUIPMENT AND PRACTICES

Good Practices When Installing Tubes and

Tube Fillings
Installing Tubes
1. Always replace tubes with ones of iden-
tical shape. size and material. A

2. Use as few fittings as possible by making

bends in the tubing where practical.
3. Route the tubing as follows:
(a) Use as few sharp bends as you can
X PO
and make the bends as gradual as AGood Bend CKinked Bend
possible. Use the proper tube ben- B Flattened Bend DWrinkled Bend
ding tools to prevent flattened. 1

kinked. or wrinkled bends (Figure 1- (1-180) GOOD AND BAD BENDS IN TUBING
180). The bends shouid be accurate
Courtesy of John Deere i.td
and smooth so that they do not
restrict flow. As a general rule. the
radius of the bend should be three to
live times the diameter of the tubing. Installing Tube Fittings
but follow the manufacturer's recom-
mendations.
1. The most important rule for tightening
tube fittings is: tighten only until snug. Do
(b) Avoid routes that interfere with the not over tighten. More damage has been
operator. moving parts. access doors done to tube fittings by over tightening
or controls. Keep the lines from than by any other cause.
protruding if possible.
2. Where necessary. use two wrenches on
(c) Avoid straight-line hookups where the fittings to avoid twisting the lines.
possible (Figure 1-181). They rnake
the line difficult to remove and do not 3. If a fitting starts to leak and appears
allow for enough expansion and con- loose. retighten it only until the leak stops.
traction.
(d) Support long tubing runs with
brackets or clamps. Group lines and
clamp them together for a neater ap-
pearance.
(e) Do not route tubes through
bulkheads or walls if you can avoid it.
However. if it can't be avoided. use
bulkhead connectors.

WRONG WRONG

(1-181) ROUTING OF TUBES

Courtesy of Jowl Deere Ltd

112
 SHOP EQUIPMENT AND PRACTICES 1:97

QUESTIONS HOSES, PIPES, TUBES, 8. Tubing is sized by its:

FITTINGS AND ADAPTERS
(a) ID alone
1. The dasn number used for sizing (b) OD alone
hydraulic hose refers to its inner
diameter in: (c) ID and wall thickness
(d) OD and wall thickness
(a) 1/8th of an inch
(b) 1/32nd of an inch 9. Piping is sized by its:
(c) 3/16ths of an inch (a) OD
(d) 1/16th of an inch (b) ID

2. Generally speaking as the size of a hose

(c) ID and wall thickness
increases its working pressure: (d) OD and wall thickness
(a) decreases 10. Match the following illustrations of fit-
tings with their name:
(h) increases
(c) stays the same
(d) none of the above
3 When making up a hose that requires the
end to be skived to install the
replaceable fitting. the amount skived is:
(al two times the diameter of the fitting
(b) VI the diameter of the hose
(c) the length up to the notch on the fit-
ting socket
(d) the length of the fitting
Flexible hydraulic lines must be long 3
2nough to allow for
ta) vibration
(b) heat expansion
(c) full extersion or action of he ac-
tuator
(d) all of the above
5 JIC and SAE are the two types of
reusable hose end fittings used in
hydraulic system piping. These fittings.
(a) are completely interchangeable
(b) have different seating angles and
thread pitches
(c) have the same seating angles and
different thread pitches

6. Why is galvanized pipe not recom

mended for hydraulic lines?
iron pipe fitting
7. Why is copper tubing not recommended solderless compression fitting
for hydraulic system piping?
inverted flared fitting
double compression fitting
SAE flared fitting

113
 1:98 SHOP EQUIPMENT AND PRACTICES

LIFTING AND BLOCKING Shop Cranes

Lilting and blocking equipment and lilting and Some shops have overhead cranes that run on
lowering heavy components is a routine part tracks. These tracks may be over top of 3 sec-
of a mechanic s work. This section discusses tion of the shop or they may run the complete
common types of lifting equipment. chains. length of the shop. The crane hoist may be
strings. rigging hardware. and stands end electric. air or hand operated, depending on
blocking found in heavy duty shops. Safety its size and lifting capacity which can range
when lilting Is stressed. from one or two tons to over fifty tons.
TYPES OF LIFTING EQUIPMENT Gantry A-frame cranes (Figure 1-183) are
common in smaller shops. They are equipped
Cranes Mobile with large castor wheels permitting them to be
Shop (overhead bridge, and port- moved around the shop to where ever they are
able gantry A-frame) needed. They have either heavy wall pipe or (-
beam construction. Hoists used with A-frames
Fork lifts (Figure 1-184) are usually hand operated,
although smaller ones may use a lever-
Hydraulic Hoists and Jacks operated come along (Figure 1-185). Lifting
capacities of gantry A-frames depend on the
Mobile Cranes strength of the frames material and on the
There are many makes and sizes of mobile capacity of the hoisting equipment. Note that
cranes with lilting capacities ranging from all overhead lifting equipment must have its
one or two tons to over a hundred tons. Mobile lifting capacity clearly marked on it
cranes can be diesel or gasoline powered.
can have cable or hydraulic lift. and can have
two. four. or six wheel drive depending on
their size. A large hydraulic mobile crane is
shown in Figure 1-182: the advantage of a
crane like this is it can be moved quickly from
lob to job.

(1-183)
GANTRY A-FRAME CRANE

4r* JIMI.all.
...----111111)..11Lr.....-

(1-182) Courtesy of Harnischfeger Corporation. P&H

114
 SHOP EQUIPMENT AND PRACTICES 1:99

C 47
(1-184) HAND HOISTS (1-185) COME ALONGS
Courtesy of Clark Equipment Co. Courtesy of Clark Equipment Co.
Fork Lifts
HYDRAULIC HOISTS AND JACKS
Forklifts (Figure 1-186) have become common
pieces of lift equipment around mechanical Hydraulic hoists lift from above, while
shops mainly because of their mobility and hydraulic jacks push from below. Both have
versatility. Originally intended for moving single acting hydraulic cylinders, and have
loads on pallets from one spot to another, pumps and reservoirs integral to their
forklifts can also do various hoisting jobs in a assemblies A typical mobile floor hoist is
shop. They are, however, limited in reach and shown in Figure 1-187. The lifting reach can
height. Forklifts are available in lifting be changed by extending the boom in or out.
capacity from 2 to 20 tons and more. However, keep in mind that as the boom ex-
tends, the lifting capacity decreases. Note
that the lifting capacities of these types of
mobile hoists are rated wain the lift arm fully
retracted.

(1-1P6)
(1-187) HYDRAULIC FLOOR HOIST
Counesy of Clark Equipment Co Courtesy of Owatonna Tool Company

115
1:100 SHOP EQUIPMENT AND PRACTICES

The hydraulic jacks used in heavy duty shops

are: floor jacks. transmission jacks, and wheel
dollies (Figure 1-188). These are all portable
and have single-acting cylinders. The lilting
capacities of these jacks range from 114 ton to
100 tons. Following are some rules for correct
use of jacks:
1. Select a lack with sufficient lifting
Capacity to do the job. FLOOR
JACK
2. To prevent a vehicle from rolling, block
wheels that are not being jacked.
3 Always place the jack on a firm footing.
4 When placing the jack. select a good flat
area to lack against
5 When jacking one side of a vehicle or
piece of equipment. place the jack as far
to the outside as possible.
6 DJn't trust a lack to support the vehicle or
machine once raised. Block it with ap-
proved blocking or stands. WHEEL COLLIE
ogiMass.

-z_z--.-

16

TRUCK JACK

TRANSMISSION JACK

(1-188) HYDRAULIC FLOOR JACKS

Courtesy of Neon-Werner

.116
 SHOP EQUIPMENT AND PRACTICES 1:101

CHAINS AND SLINGS Care and Use Of Chains

To lift a load from above. regardless of the 1. Don't overload chains. Know the lifting
types of lifting equipment used. requires capacity of the chain. and know the
chains or slings. Chains and slings are often weight of the object you're lifting.
used interchangeably. whatever is available at
the time. 2. Don't put a knot ir a chain to shorten it.
nor try to shorten it with a bolt.
CHAINS 3. Never replace links in a chain with shop-
A general rule of rigging is don't use chain if made ones.
you can use wire rope. The reason for this is 4 Never weld or heal alloy steel chain links.
simple: if one link on a chain breaks. the
whole chain breaks. whereas all the hundred 5 Don't try to lift a load with the tip of a
or so wires on a wire rope must break before it chain hook.
will break. However, there are some jobs such
as lifting engines. suspension parts and large, 6 Be sure that chain fittings are the correct
heavy castings where chain is better than wire size. type and grade for the chain.
rope. The chain is flexible. it doesn't kink like
wire rope, it holds the piece well, and stands
up to rough treatment. Note that all chain safe
for lifting has an "A" stamped on its links
standing for heat-treated alloy steel.
Chain is available in link thicknesses starting
from 1/4 inch and increasing in increments of
1/8 inch. The lifting capacity of chain is rated
according to link thickness, e.g.. 3/8th inch
chain has a capacity of 6600 pounds and 1/2
inch chain 11250 pounds.

Inspecting Chains
Inspect regularly used chains at least once a
month. Each link of the chain must be
checked. Chain inspecting procedures are:
1. Wash the chain in solvent.
2. Place the chain on a flat surface or
suspend it.
3. Check for elongated or stretched links.
Two signs of this are links that stick
together. or a chain that won't hang
straight. Stretched links are caused by
overloading.
4. Check for worn, twisted. bent links. Also
look for large nicks. cuts. gouges that
could make the chain unsafe. Tables are
available that show the allowable amount
of wear or depth of cuts for chains.
5. Closely .heck for cracks in the links. If
cracks me found. the chain is unsafe to
use. *rid should be discarded.

117
 1:102 SHOP EQUIPMENT AND PRACTICES

WIRE ROPE SLINGS Common configurations of wire rope slings

are single (Figure 1-189). choicer (Figure 1-
Wire rope slings are used for straight lifting 191) and bridle (two. three and four part)
from lilting eyes. and for lifting objects of a (Figure 1-192).
shape that allows the rope to have gradual.
uniform curvature when wrapped around it.
Wire rope slings should not be placed around
sharp corners because they will kink and
thereby loose much of their lilting capacity.
Wire rope slings are available in a number of
diameter sizes. lengths and ends. Diameter
sizes vary from one-quarter inch to two inches
(See Figure 1- 1i89). Lengths vary with the sling
application. but there is a minimum length.
Ends of slings are usually eye splices. the
best being a mechanically crimped Flemish
eye splice. Thimbles are recommended in the
eyes (Figure 1.190).

Standard
Rope Loop Sizes Minimum
Diameter Inches Sling

H Inches
A B
Length

T %
5/16
2
2 Y2
4
S
1'6"
2'
i_ 3 6 2'
7116 3 6 2'6"
1/2 4 8 2'6"
9/16 4 8 3'
5 10 3' (1-191) CHOKER SLING
6
3,6,,
SLING SL % 12 Courtesy of MartonBlack
LEN 3TH % 7 14 4' Wore Ropes Ltd.
1 8 16 4'6"
1% 9 18 5'
1% 10 20 5'6"
1% 11 22 6'
1 1/2 12 24 7'
134 13 26 8'
1% 14 28 8'
17/it 15 30 9'
2 16 32 9'

(1-189) BASIC SLING SIZES

Courtesy of MartmBlack Wire Ropes Ltd

EYE WITH THIMBLE

EYE WITHOUT THIMBLE

(1-190)
Courtesy of MartonBlack Wore Ropes Ltd

118
 SHOP EQUIPMENT AND PRACTICES 1:103

-1Bh-
A

LENGTH
LENGTH OF
OF SLING
(SL)
SLING
(SL)

2-PART
3-PART

LENGTH
OF
SLING
(SL)

4-PART
Courtesy 01 Marton-Black Were Ropes Ltd
(1 -192) BRIDLE SLINGS

119
1:104 SHOP EQUIPMENT AND PRACTICES

Lifting capacity is an Important consideration 2. Check for kinks and twists Badly kinked
with slings. it depends on wire rope diameter. or twisted ropes should be discarded
sling configurations and lifting angle. Figure
1-193 shows the lifting capacities of single 3. Check the eye for signs of failure at the
slings making both a vertical lift and a basket outer end and at the crimped loin.
hitch lift. Note the greater lifting capacity of
the two part basket hitch. The lilting capacity
of bridle slings depends on the Idling angle of Care and Use Of Wire Rope Slings
the line parts For example. on a half inch. 1. Hang up the slings when not using them.
three part bridle sling. if the lifting angles are
30 degrees from the vertical. the sling's lifting 2 Use shackles to connect sling eyes to lift-
capacity is 9730 pounds. but if the angles are ing eyes.
increased to 60 degrees the lifting capacity is
reduced to 5600 pounds. In other words, the 3 Protect the rope with blocking or pads
greater the lifting angle of the line parts of a when it passes around sharp corners.
bridle sling the less its lifting capacity.

BASKET HITCH VERTICAL LIFT

Rope Diameter
Inches Pounds Pounds

% 1,840 920
% 4,040 2,020
% 7,470 3740
34 11,210 5,600
34 16,160 8,080
% 21,790 10,900
1 28,360 14,180
1% 33,320 16,660
1% 41,480 20740
134 50,680 25,340
1% 61,240 30,620
BASKET HITCH VERTICAL LIFT 134 71,800 35,900
1% 82,330 41,170
1% 96,640 48,320
(1-193) 2 105,520 52,760
CointesY of Marlin-Black Wire Ropes Ltd 4. Don't pull slings from under loads be-
cause this causes unnecessary wear on
Inspecting Wire Rope Slings the rope and can kink it.
Wire rope slings. like chains. should be in- 5. Don't drop loads on slings or run over
spected on a regular basis. although. because them with heavy equipment as crushing
of their construction. they don't require as limits the service life of slings.
careful examination as chains To inspect
wire rope slings. 6. Whenever possible keep the sling lifting
angle from the vertical to 45 degrees or
1 Look for broken outer wires and signs of less. Figure 1.194 shows the effects of
stretching. sling angle on sling load. Note that once
the angle reaches 60 degrees. double the
amount of strain is put on the sling com-
pared to lilting vertically.

1000 LBS 11000 LBSI

( 1-194 ) EFFECT OF SLING ANGLE ON SLING LOAD

120
 SHOP EQUIPMENT AND PRACTICES 1:105

RIGGING HARDWARE

HOOKS
Common types of hooks are slip hooks. safety
hooks. grab hooks. and choker hooks An eye
slip hook and a clevis slip hook are shown in
Figure 1-195. Safety slip hooks in solid or
swivel forms are also available (Figure 1-196).
Figure 1.197 shows an eye grab hook and a
clevis grab hook A sliding choker hook is
shown in Figure 1-198).
Slip hooks and grab hooks are generally used
with chains. although sometimes slip hooks
SAFETY HOOK SWIVEL SAFETY HOOK
are attached to the eye of a sling such as on
bridle slings The clevis type of slip or grab (1-196) SAFETY HOOKS
hook is handy as it can be put on or taken off Courtesy of Martin -Black Wore Ropes Ltd
to suit the lob Choker hooks are made to
slide on wire rope.

Inspection, Care and Use Of Hooks

1. Critical inspection points for hooks are
shown in Figure 1-199). Severely worn.
twisted or spread hooks are unsafe and
should be discarded.
2 Lift only in the saddle of the hook )n't
lilt at the point The further 11 ad is
moved from the saddle to tht point the
less the hook is capable of lifting. For
example. a hook at the point can carry CLEVIS GRAB HOOK
only approximately 400o of its rated load. EYE GRAB HOOK
(1-197) GRAB HOOKS
3. Ensure that grab hooks are the correct Courtesy of Crosby-Laughlin
size to fit the chain they are used with.
4. Whenever possible use hooks with safety
catches.

CHECK FOR SPREADING

OR TWISTING

CHECK FOR WEAR

EYE SLIP HOOK CLEVIS SLIP HOOK

(1.195) SLIP HOOKS 411111111011
Courier -,8 crosuy-Laughum (1.198)
SLIDING CHOKER HOOK
CHECK FOR Courtesy of CrosbyLaughlut
TWISTING
AND
CRACKS CHECK FOR WEAR IN THE
SADDLE AND FOR CRACKS
(1-199) INSPECTING HOOKS

.
121
 1:106 SHOP EQUIPMENT AND PRACTICES

SHACKLES
PACKINGS HOOK
Shackles are used to couple a chain or sling
to a lifting hook or to a load. Two common
types of shackles are bow-type and D-type
(Figure 1-200). The D-type is usually longer,
whereas the bow-type is wider and will fit a
larger lifting hook. Shackles are sized ac-
cording to the diameter of the body of the
shackle rather than pin diameter. Safe
working loads of shackles depend on their
size, e.g., a three-quarter inch diameter forged
alloy steel shackle has a safe working load of
four and three-quarter ions.

WRONG RIGHT
LOAD OFF CENTER LOAD CENTERED
(1-202)
LIFTING EYES.
Lifting eyes are used to lift odd shaped parts.
Components such as transmissions. cylinder
BOW-TYPE D-TYPE
heads and engine blocks often have con-
veniently taped holes for lifting eyes to be
(1-200) SHACKLES threaded into. Lifting eyes are available in a
counesy of Crosby-Laughlin
variety 01 thread sizes but generally only in
Inspection, Care and Use Of Shackles N.C. thread. They are made from forged alloy
steel and are most useful when equipped with
1. Figure 1-201 illustrates the critical in- shoulders or collars. Plain eye bolts (Figure 1-
spection spots on a shackle 203) are okay for vertical hits but when angle
2. Use only forg d alloy steel shackles loaded they are subject to bending and have a
reduced safe carrying toad. A pipe sleeve with
3. Don't use a bolt in place of a shackle pin a thick washer on the top (Figure 1-204) will
as it may be of a lower grade steel and will support a plain eye bolt when a shoulder eye
bend. bolt is not available
4. Discard spread, twisted or bent shackles.
5. Loads must ba centered on the shackle. If (1-203)
PLAiN EYE BOLT Courtesy of Owatonna
need be use washers or spacers to center
a load on the pm (Figure 1-202). II the load Tool Company
AC-754
is lifted off-center, the shackle has
reduced lifting capacity, and it will likely
be damaged. 1 8" THICK
FLAT WASHER
6 Fully install screw pins
7. Lock all round pin shackles with cotter
pins.

CHECK FOR WEAR

AND BENDING PIPE
CHECK FOR WEAR
(DISCARD IF MORE
THAN 10%)
CHECK FOR
CHECK THAT PIN SPREADING OR ISOM
SEATS PROPERLY TWISTING (1-204) LiFTiNG EYE WITH MAKEUP COLLAR
(1-201) Counesy of CrosbyLaugnim %,ourtosy of Caterpillar Tractor Co

122
 SHOP EQUIPMENT AND PRACTICES 1:107

Bolt-on lilting eyes made for lifting light loads SPREADER AND EQUALIZER BEAMS
are also available (Figure 1-205). They are
made of forged alloy steel and the link is per- Spreader beams (Figure 1-207) balance long
manently attached. The Mt must be made in loads during lifting. preventing them from tip-
line with the angle of the link ping. laming or sliding. Equalizer beams
(Figure 1-207) equalize the load over the
length of the object lifted.
Spreader and equalizer beams are often made
up in the shop. rather than gurchased. and are
used for jobs such as lifting heavy engines.
Shopmade beams should have the lifting
capacity marked on them. in addition to the
job the beam is intended for.

(1-205) BOLT ON LIFTING EYE

Use and Care 01 Eye Bons
1. The taped hole for the eye bolt should be
of adequate depth: at least one and a half
&4)
times the diameter of the bolt.
1111[] 1i11111111111MNIMINI1111111111111111Ii

2. When puling an angle load on an eye.

make sure that the load pulls in line with
the eye rather than at right angles to it.
Otherwise. the eye will bend (Figure 1-
206). Shims may be necessary to line the SPREADER BEAM
bolt up and at the same time to keep it
tight.
3. Always use a shackle with an eye bolt:
never put the point of a hook into an eye
bolt.
4. Don't run a sling through two eye bolts.
Attach a separate sling to each bolt.
5 Angular loading is not recommended for 1111111111111111111111111111111111111111111111111111111ifill

plain eye bolts without shoulders.

6. Angle loading greater man 45 degrees
from the vertical is not recommended with
eye bolts.
EQUALIZER BEAMS

..- c;
11111111114111111111111111111111MIIIIM1111111111111111[1[111

ci

RIGHT WRONG
PULLING IN LINE AT RIGHT ANGLES (1-207)
(1-206)
123
1:108 SHOP EQUIPMENT AND PRACTICES

BLOCKING AND STANDS

Wnenever raising a piece of equipment or a
vehicle to work on it. proper blocking or
stands must be used to support it. Both wood i seat t dig all ilk
blocking and stands are acceptable for shop
work. es long as they are heavy enough for I
the lob Examples of truck stands are shown
in Figure 1-208 and equipment stands in
Figure 1-209
.47

T10

(1-210) BLOCK BRIDGING

Courtesy of Caterpillar Tractor Co.

In the field, if possible. move the machine or

equipment to firm level ground before jacking
(1-208) TRUCK STANDS and blocking. Make a bridging with wood
Courtesy of NeinWerner blocks. the largest ones at the bottom to form
a sound base.

A
lie

CY
BLOCKING UNDER
THE SCRAPER
DRAFT TUBE

.. Th1413

111111%;71(1;
(1-209) EQUIPMENT STANDS
Courtesy of Caterpillar Tractor Co
At,
When wood blocking is used. select firm
square blocks, and place them as shown in
Figure 1-210. This arrangement ci! blocks is
called bridging: it provides a wide, solid base
for the machine. In this example note also
how blocks have been placed at the front and
rear of the tires to prevent the machine from
rolling Other examples of blocking are shown
in Figure 1-211

19949
BLOCKING THE FRONT OF
THE TRACTOR
Counesy of Caterpillar Tractor Co

124
 SHOP EQUIPMENT AND PRACTICES 1:109

LIFTING PROCEDURES AND PRECAUTIONS 2. If the center of gravity of the object being
lifted is not in line below the hook, the
Lifting procedures and equipment depend on load will shift. In Figure 1-213 the center
four factors:
of gravity of the transmission is not quite
the object to be lifted in line with the hook so a bolt has been in-
its weight stalled through the chain link just un-
derneath the hook. This bolt will prevent
the lifting and blocking material the transmission from shifting. Note the
available lifting eyes and the angle iron lifting
the decision to lift from above or jack bracket that have been installed for this
from below lift. Lifting brackets can be easily made in
a shop (Figure 1-214), or purchased from
Good Practices When Lifting manufacturers or tool companies (Figure
1.215).
1. Find the weight of the object to be lifted;
service manuals are the best source for
this information. The diesel engine shown
in Figure 1-212 could weigh, with all its
accessories, from 2000 to 4000 pounds.
Note the equalizer beam and lifting
brackets.
A

(1-214) SHOP-MADE LIFTING BRACKET

Courtesy of Caterpillar Tractor Co.
Hoist Chorus

At-

V10005 1. w.
(1-212) LIFTING AN ENGINE
Courtesy of Cummins Engine Co.
"";

0;4 r. .1k9
.' .cgt

,:%440fr

(1-213)
REMOVING OR INSTALLING TRANSMISSION

411=.-- c
Courtesy of Ford Motor Company

125
1:110 SHOP EQUIPMENT AND PRACTICES

6. Never attempt to work on a machine or

component while it is jacked or hoisted
up. Block it or put it on stands first (Figure
1-218).

,'2

1 lirl
(1-215) LIFTING BRACKET
Courtesy of Owatonna Tool Co
7.
8.

9.
Never walk under a lifted object.
Lift an object only as high as necessary,
then lower it as soon as possible. Never
leave it suspended.
Always keep the load under control. If
necessary tie a tag line on the load to
prevent excessive swinging.
10. Keep your hands clear of sling pinch
points when the sling tightens for the lift.
11. Keep others away from a load that you
are lifting or lowering.
12. Never ride on a load while it is being
raised or lowered.
13. Raise and lower objects slowly.
14. In a situation where lifting brackets or
lifting eyes are not available and a chain
must be wrapped around a component to
lift it, be careful to place the chain so
(1-216) HYDRAULIC JACK that it does not slip and does not apply
Courtesy of Hem-Werner pressure to accessory parts.
3. Before using a hydraulic jack, be sure it
has the capacity to lift the load (Figure 1-
216).
4. When using a hydraulic jack make sure
the threaded jack extension is well within
its limit.
5. Use an equalizer bar to distribute the
load whenever possible (Figure 1-217).

INCORRECT

(1-217) LIFTING ENGINE

Courtesy of Caterpillar Tractor Co

(1-218) SOUND BLOCKING

Courtesy of Construction Industry
Manufacturer's Association

126
 SHOP EQUIPMENT AND PRACTICES 1:111

QUESTIONS LIFTING AND BLOCKING 12. A spreader or equalizer bar made in a

shop should:
1. What are the three basic types of lilting
equipment? (a) be painted so it can be easily seen
2 For safety. what must all overhead lifting ib) have its lifting capacity marked
equipment have? clearly on it
(c) have the job it was intended marked
3. Once a vehicle is ja;:ked, what must be on it
done?
(d) both (b) and (c) are correct
4. What is the main disadvantage of chain
compared to wire rope for lifting? 13. Two acceptable methods of supporting
raised machinery are and
5. Why are chains better than slings for lift-
ing irregular shaped objects?
14. When blocking is placed in a crisscross
6. On a two part sling, does the loading in- pattern. it is known as
crease or decrease as the angle between
the sling and load becomes less than 90 15. Where would you look to find the weight
degrees? of a component?
7 The lifting angles on two or three part 16. When you discover a crack in a chain:
wire rope slings should be kept under (a) cut out the cracked link and join the
degrees.
chain up
8. True or False? Slip hooks and grab (b) make up a new link in the shop
hooks are both made for use with wire
rope slings. (c) discard the chain
(d) ignore the crack
9. The size of a shackle is given by:
17. Name three things to look for when in-
(a) the width of the bow specting the chain.
(b) the length of the bow
18. If a wire rope sling has to pass over a
(c) the diameter of the material in the sharp corner on the object its lifting.
bow what should be done?
10. When a shouldered lifting eye is not 19. True or False? Hooks are designed so
available. a plain eye can be used if: that lifting is done on the tip of the hook.
(a) it is large enough 20. When attaching a sling to a lifting hook.
(b) it is screwed further into the casting use a
(c) a shackle is used as well
(d) a pipe sleeve and washer are used
to support it and prevent it from
bending
11. A taped hole for a lilting eye should have
a minimum depth of:
(a) two times the bolt diameter
(c) one and one-half times the bolt
diameter
(c) three times the bolt diameter
(d) at least equal to the bolt diameter

127
 fa)

1:112 SHOP EQUIPMENT AND PRACTICES

WELDING 10. Do not refer to oxygen as air or to

acetylene as gas. Refer to them as
WELDING AND CUTTING oxygen and acetylene.
Heavy duty mechanics use oxyacetylene 11. Handle cylinders carefully and never
equipment to cut materials for fabrication, for drop them. Use a cradle or a holder when
removing seized parts. and for removing lifting them with a crane. Never use a
welded parts. They may also do some basic magnet to lift cylinders.
flat welding and brazing, for example, when
fabricating exhaust systems and repairing 12. 8e sure the cylinders are fastened so
broken components on various types of equip- that they cannot move during trans-
ment. Heavy duty mechanics, however. unless porting. Lift. rather than slide a cylinder
they have a welding certificate, should not from the vehicle and keep the cap in
consider themselves as qualified welders. place.

The purpose of this section is to give the 13. Never roll cylinders or use them as
essential information needed for safe handl- rollers.
ing, set up. and operation of oxyacetylene 14. Keep oil and grease from the cylinder
welding. cutting, and healing equipment. valves.
CYLINDERS HANDLING, STORAGE 15. Store cylinders securely where they can-
AND SAFETY not fall or be struck by mechanical or
other objects. and where they cannot
1. The storage and handling of oxygen and contact salt or corrosive chemicals or
acetylene cylinders are governed by the fumes.
Fire Marshal's Regulations. These
regulations also specify the safety 16. Cylinders should be kept in an upright
precautions that must be taken when position when in use and in storage.
welding and cutting. Although general
precautions for the handling and storage 17. Cylinders should be used in the order
of cylinders vs given here, take the Fire that they are received from the supplier.
Marshal's Regulations as the authority. 18. Cylinders should not be placed in
2. Be sure the cylinders contain the proper locations where sparks or flame from
gas and are stored with like gas cylin- welding or cutting can contact them.
ders. Never mix unlike gas cylinders. 19. Extreme care must be taken to ensure
3. Protect the cylinders against the weather that the arc from an electric welder never
when stored outdoors, particularly touches a cylinder.
against ice, snow, and direct rays of the 20. Cylinders should never come into con-
sun. tact with bare electric wires.
4. Store empty cylinders separately from 21. To prevent serious explosions. oily and
lull cylinders, and mark the empty ones greasy substances must be kept from
so they can be recognized. oxygen cylinders. valves. hoses and ap-
Do not store cylinders close to hot sur- purtenances.
5.
faces such as radiators or stoves. 22. Do not attempt to repair cylinder valves.
6. Be sure cylinder storage rooms are well 23. Make sure the valve is tightly closed
ventilated. when handling the cylinder. Do not
7. Chain or fasten cylinders to a carrier. or remove the key from the valve while the
to a fixed object, when in use. cylinder is in use.

8. Protection caps should be in place on 24. Remove a leaking cylinder into the open
the top of the cylinders when they are in
air at a safe distance from any type of
flame.
storage and when they are being moved
to and from the shop or storage area. 25. Do not tamper with the fusible safely
plug on acetylene cylinders.
9. Always close the cylinder valves when
the equipment is not in use. 26. Keep the top of acetylene cylinders away
from tools and other objects.

128
 SHOP EQUIPMENT AND PRACTICES 1:113

HOSE AND CONNECTIONS 8. Never use oil or grease to make con-

nections.
Hoses and connections carry the oxygen and
acetylene at reduced pressures from the cylin- 9. Never use tape to repair a hose.
ders to the welding or cutting head at-
tachment. Following are rules for safe use of REGULATORS
hose and connections:
The regulator is a device connected to the
1. Use only first-grade quality hose. cylinder that reduces high pressure in the
cylinder and maintains a constant working
2. Hose should be protected at all times pressure. The basic principle of operation of a
against damage and misuse. single stage regulator is that a spring. con-
3 Hose should be placed so that it will not nected to a handle. exerts pressure on a
create a tripping or stumbling hazard. diaphragm (see Figure 1-219). The diaphragm
in turn is connected to a valve which controls
4. Oxygen hose should be green and the flow of gas from the cylinder through the
acetylene hose red. regulator to the torch. When adjusting screw
is turned in. the spring presses onto the
5. Connections should be either the ferrule diaphragm opening the valve and permitting
or the clamp type. capable of withstan-
the gas to flow at a certain pressure.
ding. without leakage. a pressure equal
to twice the maximum delivery pressure Any pressure higher than the set 'working
of the pressure regulators provided. pressure' tends to close the valve. thus
reducing the flow and maintaining a constant
6 Standard oxygen equipment has right- working pressure Only the stem. seat. and
hand threads. and acetylene equipment
diaphragm are likely to need replacement on
left -hand threads. The connections must a single stage regulator.
never be forced.
7. Hose should be frequently examined for
leaks and defects.

VALVE REDUCES INLET

PRESSURE TO DELIVERY
PRESSURES UP TO 150
LBS. PER SQUARE INCH

OXYGEN ENTERS THE

INLET AT PRESSURES
/ PRESSURE
ADJUSTING
UP TO 2200 LBS. PER SPRING
SQUARE INCH eN

VALVE SEAT
INLET PRESSURE Af
FILTER ADJUSTING *...)
QUA ET 0- SCREW

DIAPHRAGM

(1.2 19) CROSS-SECTION OF SINGLE-STAGE

OXYGEN REGULATOR

k 129
1:114 SHOP EQUIPMENT AND PRACTICES

Two stage regulators are also available: they

are actually two regulators in one in which the
incoming gas pressure is first cut to an in-
termediate pressure and then to working
pressure. They have greater accuracy of ad-
justment than single stage regulators and are
recommended for precision cutting or VALVE STEM PACKING
welding. for heavy hand-cutting or welding.
and for production machine welding or cut-
ting operations. SEAT #2

OXYGEN AND ACETYLENE CYLINDERS

Oxygen Cylinders RUPTURE DISC E::::

Oxygen cylinders are rented rather than sold. SAFETY DEVICE
remaining the property of the oxygen
manufacturer. At the slightest indication of
weakening or sign of damage. the cylinders
are withdrawn from service. Cylinders are
made in a variety of sizes ranging from 55
cubic feet to 244 cubic feet. A large full cylin-
der weighs 152 pounds. The oxygen is com-
(1-220) HIGH PRESSURE OXYGEN VALVE
pressed to 2700 psi at 20°C. As the tem-
perature decreases the pressure decreases Liquid oxygen cylinders are another type of
e.g.. at -18°C oxygen pressure in the cylinder oxygen cylinder. They are mainly used where
is 1780 psi. large quantities of oxygen are needed, having
The cylinder valve (Figure 1-220) is made to the advantage of reducing the size and weight
operate at high pressures. The double seat of the container. These cylinders are refilled
construction prevents leakage of oxygen from a liquid oxygen tank wagon. Note that
around the ;tem when the valve is turned the oxygen in liquid oxygen cylinders is not
open all the way. The safety device in- under very high pressure. but it should be
corporated in the valve. consists of a pressure drawn from the tank at a fairly steady rate.
or rupture disc which will bursi and release Closing down the oxygen draw for a period of
the oxygen before the cylinder will rupture time will result in a pressure build-up which
due to excessive heat. The valve outlet fitting will activate the safety valve and release
is a standard male thread to which all stan- oxygen.
dard made pressure regulators may be at- Acetylene Cylinders
tached. Before attaching. the valve should be
cracked (opened briefly and reclosed) to Acetylene cylinders (Figure 1-221) are filled
remove any dirt that may be lodged in the seat with a porous material such as asbestos. char-
which might plug the regulator. coal. balsa wood. etc.
No attempt should be made to repair a The porous filler material is saturated with
damaged valve or seat. Notify the supplier acetone. a special liquid which is straw-
colored and belongs to the hydrocarbon
family. It is flammable. quite volatile and has a
strong odor. Acetone has the ability to absorb
acetylene gas and is used in cylinders to
make them sale at high pressures. One
volume of acetone will absorb twenty volumes
of acetylene gas at atmospheric pressure.
This ratio increases as the pressure is in-
creased. Acetylene cylinders have capacities
to 350 cubic feet and a pressure of ap-
proximately 250 psi. Note that acetylene cylin-
ders must be used in an upright position.
otherwise the acetone will flow into the
regulator. hose, and torch and plug them.

130
 SHOP EQUIPMENT AND PRACTICES 1:115
SAFETY
CAP

RECESSED
TOP
VALVE

FUSIBLE PLUGS

POROUS FILLER

WELDED STEEL
SHELL

FINE ASBESTOS

FUSIBLE PLUGS
-____,
(1-221) ACETYLENE CYLINDER

OXYGEN AND ACETYLENE GASES atoms of hydrogen. It is flammable and burns

within a range of 3% acetylene and 97% air to
Oxygen 87% acetylene and 13% air,
Oxygen (symbol 0) is a colorless, odorless, Acetylene gas is colorless. but has a strong
and tasteless gas at ordinary temperatures pungent odor. Thus as little as one per cent
and is slightly heavier than air. Oxygen forms acetylene in the air can be smelled. Acetylene
approximately 20 per cent of the air we is explosive. If any is smelled extinguish open
breathe, the remainder being composed of flames and ventilate the room.
about 78 per cent nitrogen and the rest other
gases Oxygen cylinders contain pure oxygen. Acetylene is an unstable compound, that is. it
has a tendency to break down or undergo a
Combustible items burn much more rapidly in chemical change without much provocation.
pure oxygen than in air. Steel is not con- When this occurs. acetylene is said to have
sidered a combustible material, but when reached its critical point. The critical point of
heated red-hot and oxygen is applied it will acetylene is 28 psi pressure at 21 C. At this
burn quite rapidly, reducing the reacted metal point. acetylene breaks down into its com-
to iron oxides Oxyacetylene flame-cutting is a ponents (carbon and hydrogen). releasing its
controlled burning process Oxygen is always endothermic heat. which usually results in
a potential_ danger because it tends to speed spontaneous ignition. In other words. it ex-
up the combustion of known flammable plodes. The critical pressure is affected by the
materials, and combines readily and often temperature of the gas. If the temperature is
violently with materials not generally con- higher than 21-C the pressure at which the
sidered combustible. acetylene becomes critical will be lower than
28 psi. Thus it is understandable why the
Acetylene pressure In the acetylene hose and torch is
The chemical symbol for acetylene is C4Hj. always kept below 15 psi.
which means that an acetylene molecule is Fittings on acetylene lines must be made of
composed of two atoms of carbon and Iwo yellow brass. iron. or steel. Never use copper

131
1:116 SHOP EQUIPMENT AND PRACTICES

or red brass fittings or tubing because the WELDING TORCHES

acetylene gas will react with the copper and
form a residue that may cause an explosion at A typical welding torch of the type heavy duty
the slightest shock mechanics are likely lo use is shown in Figure
1.222. Its basic components are the acetylene
Weighing is the only accurate method of torch valve. the oxygen torch valve, the hand-
determining the amount of acetylene that has le. the brass mixing chamber, and the tip
been used on a lob or is left in a cylinder. One Note also that the acetylene hose (red) is con-
pound of acetylene gas equals 14.5 cubic feet nected to the acetylene valve on the welding
at 21 C. Thus, if you multiply the weight of gas torch and that the oxygen hose (green) is con-
by 14.5 you have the cubic foot content of nected to the oxygen valve on the torch It is
acetylene in the tank. The weight of the cylin- difficult to confuse these hoses and valves be-
der including the acetone content is stamped cause all components of the acetylene
on the cylinder. systems have left-hand threads. while those
on the oxygen system have right-hand
threads.

CYLINDER CYLINDER ACETYLENE HOSE RED

WORKING
CAP PRESSURE
PRESSURE OXYGEN HOSE GREEN
GAUGE GAUGE

OXYGEN
tv HAND WHEEL

REGULATOR

WORKING CYLINDER. CYLINDER

PRESSURE PRESSURE CAP
GAUGE GAUGE WHEEL OR
VALVE ADJUSTING
SCREW NOTE:
WRENCH
ACETYLENE OXYGEN All oxygen fittings
REGULATOR right-hand thread.
CYLINDER

All acetylene fittings

ADJUSTING telthand thread.
SCREW
ACETYLENE
CYLINDER
ACETYLENE
TORCH WELDING
OXYGEN VALVE TORCH
HOSE opiiii.. . Q

o
---111:!......,
OXYGE
BRASS COPPER SECTION
TORCH
VALVE MIXING
HANDLE CHAI1/4"3ER

ACETYLENE
HOSE

.
W.44iM 7t7k9rAWA/4M f iriX/MgifiC fA //Wife//0.4
(1-222) OXYACETYLENE WELDING SET-UP

132
 SHOP EQUIPMENT AND PRACTfCES 1:117

Cleaning Tips To clean a torch tip using a drill:

The tips of welding torches must be kept Select the correct size of drill. (do not use a
clean and in good condition. Tip cleaners or drill that is larger than the orifice). Small drills
drills are used for this purpose. The are very brittle and care must be taken not to
procedures for cleaning a torch tip with a tip apply too much pressure nor to bend them
cleaner are given below: sideways because they will break in the
orifice and create other problems.
1. Select a cleaner needle one size smaller
than the orifice in the tip. Do not force a If orifices on welding or cutting tips become
larger cleaner needle into the orifice flared they will not perform properly. To
(Figure 1-223). recondition flared orifices. remove about
1/16th inch of the tip (see the dotted line in
2. The up-and-down motion with the cleaner Figure 1-224) using a file or emery cloth so
needle has to be straight to prevent flaring that the face is square to the axis of the Up.
the orifice.
Remove with a drill the slight burr left by the
3. After withdrawing the cleaning needle. filing.
open the oxygen valve slightly to blow out
any dirt. CUTTING TIP WELDING TIP
TIP CLEANER

(1-223) FLARED ORIFICE

If
FLARED ORIFICE
(1-224) REPAIRING FLARED ORIFICES
Tip Sizes
The following tab:e is a guide to the selection
of tip sizes. oxygen and acetylene pressure.
and tip-cleaner size. Note the relationship be-
tween the tip Aze and the recommended
pressure. For more specific information. con-
sult torch manufacturers' instructions.
.
Thickness Oxygen Acetylene Tip
Tip Of Metal Pressure Pressure Cleaner
Number (Inches) (Pounds) (Pounds) Size

00 1164 1 1 7
0 1/32 1 1 8
1 1116 1 1 10
2 3/32 2 2 14
3 1/8 3 3 18
4 3/16 4 4 22
5 114 5 5 26
6 5/16 6 6 30
7 3/8 7 7 34
8 1/2 7 7 37
9 5/8 7% 7'et 42
10 3/4 & up 9 9 45

133
1

1:118 SHOP EQUIPMENT AND PRACTICES

Correct Use Of Welding Torches 9. Set the correct working pressures by

turning in the regulator adjusting screws
1. Goggles must be worn at all times when until the working pressure gauge
welding or cutting. There are many dif- registers the correct pressure.
ferent types of goggles. Some have darker
glass than others. and some are designed 10. Test for leaks (see information below).
for use by workers who normally wear
glasses. Never depend on ordinary 11. Open the acetylene needle valve on the
glasses to provide eye protection when torch handle one-quarter turn and ignite
welding. Leather gloves are essential to the gas with a spark lighter. Adjust for a
Protect the welder from flying sparks and smokeless flame.
hot materials. Leather aprons should also 12. Open the oxygen needle valve on the
be worn when welding. torch handle and adjust until you get the
2. Torches should be lit by a friction lighter. desired flame.
and never by a match.
3. When torches are changed or welding is
stopped for longer than about five
minutes, all cylinder valves should be
closed.
4. A clear, unobstructed space should .be
maintained between the working point
and the cylinders so the pressure
regulators can be reached quickly.
5. Torches should not be relit from hot metal,
especially when operating in a small con-
fined space: because if the gases do not
light instantly, ignition may be violent.
SET UP OXYACETYLENE EQUIPMENT
See Figure 1-225 for illustrations of these
procedures.
1. Secure cylinders in an upright position.
2. Stand clear and crack lylinder valves to
clean out dirt and water.
3. Attach regulators making certain the
regulator adjusting screws are turned
out. loose.
4. Attach hoses to regulators.
5. Stand clear and open cylinder valves
slowly. Acetylene: one and one-quarter
turns maximum. although one-half turn is
usually sufficient. Oxygen: all the way.
6. Turn in the regulator adjusting screw.
Blow out the hoses and turn out the ad-
justing screw again.
7. Attach the torch handle.
8. Attach the proper size tip.
 SHOP EQUIPMENT AND PRACTICES 1:119

"CRACK" OXYGEN CYLINDER VALVES . . THIS

BLOWS OUT ALL OUST WHICH MAY BE 2
PRES ENT
ATTACH REGULATORS SET THE NUTS UP
SNUGLY WITH A WRENCH. NOT "PLIERS". BE-
WARE OF GREASE

3 4
ATTACH HOSE TO REGULATORS BE SURE ALL RELEASE REGULATOR ADJUSTING SCREWS
CONNECTIONS ARE CLEAN AND GAS TIGHT. AND OPEN CYLINDER VALVES

TURN JUST ENOUGH GAS TO BLOW OUT HOSE. OPEN NEEDLE VALVES OF TORCH INSERT
OXYGEN HOSE IN TORCH HEAD AND TURN ON A
LITTLE OXYGEN TO BLOW OUT INTERIOR OF
TORCH.

(1-225)

135
1:120 SHOP EQUIPMENT AND PRACTICES
AI

8
7
INSERT TIP IN TORCH HEAD AND TIGHTEN WITH
CONNECT HOSE TO TORCH TAKE CARE TO AT- WRENCH. BE SURE THE TIP IS CLEAN. USE JUST
TACH OXYGEN HOSE TO OXYGEN INLET ON ENOUGH PRESSURE TO MAKE TIP GAS TIGHT.
TORCH MAKE CONNECTIONS CLEAN AND GAS CONSULT MANUFACTURER'S CHART WHEN
TIGHT. SELECTING TIPS.

9 10

OPEN ACETYLENE NEEDLE VALVE AND TURN OPEN NEEDLE VALVES OF TORCH AND TURN
REGULATOR ADJUSTING SCREW UNTIL OXYGEN REGULATOR ADJUSTING SCREW UN-
DESIRED ACETYLENE PRESSURE IS OBTAINED. TIL DESIRED WORKING PRESSURE IS IN-
DICATED THEN CLOSE OXYGEN NEEDLE VALVE.

11
12
IGNITE ACETYLENE WITH TORCH LIGHTER
AVOID USE OF MATCHES OR OPEN FLAME. OPEN OXYGEN NEEDLE VALVE AND ADJUST
FOR NEUTRAL

(1 -228)

136
 SHOP EQUIPMENT AND PRACTICES 1:121

Testing For Leeks

Before using oxyacetylene equipment.
pressurize it by opening the cylinder valves
and turning the regulator adjusting screw un-
til the desired working pressure is shown on
the low pressure gauge. Close the cylinder
valves and observe the high pressure gauge.
A leak will be indicated by a drop in pressure
(make sure the valves on the torch handle are
closed properly).
If a leak is present locate it by using soap
suds made from a non-detergent soap (ivory)
brushed on the fittings. Hoses may be tested
by immersing them in water. Bubbles will in-
dicate a leak. Never test for a leak with an
open flame (Figure 1-226). Leaks should be
properly repaired before using the equipment.

IF Te" .HES. HOSE OR REGULATORS LEAK.

REPORT THEM TO YOUR PUSHER OR FOREMAN NEVER LOOK FOR A LEAK WITH A MATCH
IMMEDIATELY. THIS IS ESPECIALLY IMPORTANT OR OTHER LIGHT .
IF THE LEAK IS IN THE ACETYLENE GAUGE OR
CYLINDER

(1-226) LE. ,KS

137
1:122 SHOP EQUIPMENT AND PRACTICES

Oxyacetylene Flames
Three types of flames (Figure 1-227) are
produced by adjusting the needle valves con-
trolling the amounts of acetylene and oxygen
being burned.
I Neutral Flame this is the ideal flame for
welding or cutting steel. The ratio of
acetylene and oxygen supplied to the
torch is approximately 1 : 1. Melted steel
flows easily and is clear and clean
Main Use Cutting
Fusion welding of
mild steel WHITE PALE BLUE
Copper LUMINOUS OUTER ENVELOPE
CONE
Cast Iron (1-227) NEUTRAL FLAME
Temperature 3260 C. approximately
2. Reducing Flame carburizing, car-
bonizing, excess acetylene.
More acetylene is supplied to the torch
than the 1 1 ratio, producing an inner
cone with a feather. The length of the
feather indicates the amount of acetylene
and is expressed in relation to the inner WHITE
cone. e.g.. "three times reducing" means INNER
that the white feather is three times the WHITE PALE BLUE
CONE
length of the inner cone. When steel is FEATHER OUTER ENVELOPE
melted the puddle is boiling and not clear.
(1-227) REDUCING FLAME
Main Use Aluminum welding.
aluminum brazing. fusion
welding of stainless steel.
silver brazing and hard
surfacing
Temperature 2980 C to 3200 C ap-
proximately
3. Oxidizing Flame excess oxygen
More oxygen is fed to the torch for this
type of flame than the 1 1 ratio of the
neutral flame, producing a shorter, more
bluish cone and somewhat shorter outer
envelope. Melting steel with this flame OUTER ENVELOPE
produces excessive foaming and sparking SHORTER. REDUCED IN SIZE
of the metal. BLUISH INNER CONE

Main Use Braze welding: Fusion (1-227) OXIDIZING FLAME

welding of manganese
Temperature Maximum 3480'C ap-
proximately

138
 SHOP EQUIPMENT AND PRACTICES 1:123

SHUTTING OFF OXYACETYLENE HEATING

EQUIPMENT
The oxyacetylene flame is a useful tool for a
When welding or cutting is stopped. first close variety of heating operations. Metals will sof-
the blowpipe acetylene valve, then the ten and become pliable when heated. Heating
blowpipe oxygen valve (Acetylene is on and may be used to straighten or bend bars and
oil first )11 the welding or cutting is to be stop- angles. Once heated. the straightening or
ped for considerable periods of time such as forming operation of the metal is done by ex-
for lunch or over night. the cylinder valve ternal force. The torch. whether a regular
should be closed and all gas pressures welding torch or a specially designed heating
released from the regulators. Take the torch such as a rose bud. should be moved
following steps: constantly to avoid overheating a small area
and possibly melting the metal.
1. Close the oxygen cylinder valve.
Heating has numerous applications in heavy
2. Open blowpipe oxygen valve to
the
duty shops. Two examples are heating seized
release all pressure from the hose and nuts or studs to help in removing them. and
regulator. heating large press-fit parts for ease of
3 Turn out the pressure-adjusting screw of removal and installation.
the oxygen regulator. When using heating equipment be careful not
4 Close the blowpipe oxygen valve. to overheat parts and not to damage parts ad-
jacent to the one being heated. Set the
5 Close the acetylene cylinder valve. regulator pressures according to tip size and
6 Open the blowpipe acetylene valve to do not hold the tip too close to the work as
release all pressure from the hose and this could cause a backfire (see upcoming in-
regulator. formation on flashbacks and backfires).
7 Turn out the pressure-adjusting screw of FLAME-CUTTING
the acetylene regulator.
Flame-cutting is accomplished by rapid
8 Close the blowpipe acetylene valve. oxidation of combustion of heated steel when
Note that the acetylene and oxygen pressures a jet of pure oxygen from a cutting torch is
should not be released simultaneously. and directed against it. The steel is cut by first
care should be taken that the release of heating a small area to the kindling tem-
acetylene does not create a fire hazard. perature with preheating flames. then direct-
ing a jet of oxygen against the preheated
area.
To prepare the welding torch for flame-
cutting. remove the welding tip and the tip nut
and attach a cutting torch assembly. as shown
in Figure 1-228.

OXYGEN VALVE
VALVE LEVER OXYGEN
TORCH HEAD ASSEMBLY
LEVER PIN FITTING CONNECTION
90 HEAD NUT
TORCH HANDLE
\ . ...i.L JU G WLL4LJULi
,
t. .
f 1: 1. JUL :1..KilttIliltl
ormseemesemoctoonc,

! TIP NUT
If )-- OXYGEN
BODY PREHEAT VALVE
TIP NUT REAR END ----- HOSE
STEM ASSEMBLY FUEL GAS CONNECTION
I. 1 CUTTING TIP VALVE ASSEMBLY GLANDS
FUEL GAS
CONNECTION
(1-228) TORCH WITH CUTTING TIP ASSEMBLY NUT
Courtesy of Air Reduction Canada Limited

139
1:124 SHOP EQUIPMENT AND PRACTICES

CUTTING TORCH TIPS Hold the torch at a very flat angle about
1'4" to 2" away from the surface of the
Cutting tips are interchangeable end pieces metal (Figure 1-230).
for cutting torches that contain openings for
the preheating flame and for the cutting Complete the cut as quickly as
oxygen stream. Tips are supplied in a variety possible to avoid undue melting of the
of sizes and styles to meet different cutting metal.
requirements. Torch manufacturers supply
their own range of tips and charts that I
'Ir..... VA"
.4---- -
Al

correlate tip sizes with material thickness. 1

recommended pressures for acetylene and

oxygen. and anticipated consumption of
oxygen and acetylene in cubic feet per hour.
For example. one manufacturer recommends
that their L-2 tip be used to cut metal one to
one and a half inches thick at an acetylene (1-230)
pressure of 5 psi and an oxygen pressure of CUTTING TORCH DISTANCE FROM THE METAL
50 psi. This cutting process will consume 15.3
cubic feet of acetylene per hour and 150 cubic An alternative cutting technique can be
feet of oxygen. used to ove:come difficulties in
following a straight-line (Figure 1-231).
For satisfactory cutting. tips must be clean Instead of running the torch straight
and in good condition (see the information make an arc while keeping the torch in
earlier on cleaning and filing tips). Note tha' the same relative position. However.
cutting tips can be adjusted to produce a only cuts of short length can be ac-
desired line of cut as illustrated in Figure 1- complished with this technique.
229

SQUARE CUT BEVEL CUT REPOSITION AND

START AGAIN ,/ ,o,4, 0
LINE OF i
i hvf IsI' 0

CUT

(1 -229) CUTTING TIP ADJUSTMENT ---APPROX.

14...

Cutting Procedures
--1..
Factors affecting the quality of a cut:
Size of cutting tip (opening)
Oxygen cutting pressurc
Speed of travel
Material thickness
Type of material (1-231)
Surface condition ARCING TECHNIQUE FOR SHORT LENGTH CUTS

Amount of preheat Cult: ig Medium Thickness Metals

Angle of cutting stream to surface (3/16" to 1 1/2")
Condition of cutting Stream opening --- Hold the torch directly above the cut-
ting line approximately 1/4 inch to 1/2
Condition of the er:d of cutting tip inch from the metal (depending upon
the length of the preheat flame).
Cutting Thin Metals
(less than 3/16" thick) Release the cutting oxygen stream only
when the metal has reached proper
Use the smallest cutting tip available. preheat temperature.
Reduce cutting oxygen pressure to 15 Tilt the torch slightly to direct the tip
psi toward the forward line of the cut.

140
 SHOP EQUIPMENT AND PRACTICES 1:125

Cutting Rounds
The technique for cutting rounds involves
holding the torch perpendicular to the work
for preheating and then following the outline
of the round (Figure 1-232). A method of star-
ting the cut is to raise a chip in the metal With
a chisel (or by welding on a drop of metal),
and to commence the cut on this raised por-
tion.

EID17Z3 (1-232)

Piercing Holes Through Metal

Since piercing holes requires a great deal of
heat. choose a tip that is at least one size
larger than the one recommended for the
thickness of the metal. Hold the torch per-
pendicular to the work until preheating is
achieved. then turn the oxygen jet on very
gradually (Figure 1-233). As the cutting
oxygen is fed. draw the tip back from the work
just enough to ensure that the slag is not
blown back into the tip openings.

(1-233) PIERCING A HOLE IN METAL I

141
1:126 SHOP EQUIPMENT AND PRACTICES

To Prevent Fires and Explosions 9. Welding areas should be properly ven-

tilated. Make sure that oxygen con-
1 Keep flames and sparks away from cylin- centrations above normal cannot
ders and hose. develop in the work area:
2 Keep protective equipment dry and free (a) Do not bring cylinders into confined
of oil. Take care that your own clothing is spaces.
not oily and that pockets and cuffs are
not open and ready to receive sparks or (b) Also if possible, light the torch out-
hot slag. side, and bring it in when lit.
(c) Avoid oxygen leaks in enclosed
3. Move the job, if possible, to an area free
spaces. Do not leave torches in en-
of combustibles. Never WOrk near ex- closed spaces when not in use.
plosive atmospheres. Avoid paint spray
rooms. dip tanks. storage areas. ven- (d) Never use oxygen for ventilation,
tilators. i.e.. never try to replace atmospheric
oxygen consumed during a welding
4. If possible move combustibles at least 30 or cutting operation. Ventilate with
to 40 feet away from the job. Sweep Me air.
floor before lighting the torch. Wet down
wooden floors. 10. When working on tanks and containers:
5. Cover combustibles with fire resisting (a) Be familiar with standard practices
shields or covers. H they cannot be for welding containers.
moved. Covers should be large enough (b) Don't weld or cut containers such as
to completely shield the material and be drums, barrels. tanks. until you
tight enough to prevent sparks from know there is no danger of fire or
going under, over, or between the covers explosion.
to the material. Use heat resisting
asbestos shields to protect nearby walls. (c) Don't depend on your eyes or nose
ceilings and floors. to decide if a closed container is
safe to weld or cut. A very small
6. Use stand-by watchers equipped with amount of residual flammable gas or
suitable lire extinguishers where the risk liquid can cause a serious ex-
of fire is great. plosion. Find out what was in the
container or use an explosimeter.
7 Inspect the area on completion of the job
to make sure that it is free of sparks. (d) Figure 1-234 illustrates the proper
glowing embers and flames. Where there way to weld a container.
is a possibility that a smoldering fire may
have been started. a watcher should be
assigned to inspect the area for half an
hour after work has been completed. or
as long as is necessary to ensure that
there is no outbreak of fire. VENT

8 Take special precautions with oxygen:

(a) Never use oxygen to dust off
clothing or work. A spark will cause
clothing in an oxygen atmosphere to
burst into flame immediately. If your
clothing becomes contaminated
with oxygen don't weld or cut for at
least 15 minutes.
(b) Never use oxygen in pneumatic
tools. in oil preheating burners. to
start engines. to blow out pipelines.
to create pressure in a container. or
anywhere. as a substitute for com- X2777 (1-234)
pressed air or other gases.
PROPER WAY TO WELD A CONTAINER
Courtesy of John Deere Ltd

:A
142
.

wry
 SHOP EQUIPMENT AND PRACTICES 1:127

BACKFIRES AND FLASHBACKS

Backfires and flashbacks are a burning back
of the preheat flames inside the equipment. In
a backfire the burning goes into the mixing
chamber. In the more serious flashback the
burning goes into the hoses and regulators
(Figure 1-235).

AREA
SUSCEPTIBLE
REGULATORS
ITO BACKFIRES
I& SURNBACKS AREA SUSCEPTIBLE TO FLASHBACKS (Includes Regulators) .7
941)
I KIT NEEDLE VALVES

HOSE
TIP
MIXER HANDLE
(1-235) BACKFIRES AND FLASHBACKS

When a backfire occurs, i.e.. the flames disap-

pear. followed almost immediately by a
squealing noise from inside the blowpipe and
by sparks coming out of the nozzle. the flames
are burning in the chamber inside the
blowpipe where the two gases oxygen and
acetylene are mixed. You should quickly do
the following: Causes Of Backfires
1. Close the blowpipe preheat-oxygen valve. 1. Too little gas flow may be caused by
low pressures or by failure to open needle
2. Close the blowpipe acetylene valve. valves enough to avoid the smoke range.
3. Close the oxygen regulator. 2. Obstruction of gai flow may be caused
4. Close the acetylene regulator. by holding the torch too close to the work,
by dipping the tip in the puddle. or by
If heavy smoke comes out of the nozzle. and if passing the rod end too close to the lip.
the blowpipe handle becomes not, chances
are a flashback has travelled beyond the 3. moose or faulty seat connections between
mixing chamber of the blowpipe and is the tip and mixer results in popping.
somewhere in the hose. You must act quickly! 4. A dirty tip metal particles collecting on
Shut off both gases at the cylinders. While the tip end. tend to retard gas flow and
closing the cylinder valves stand behind and may cause backfires. Dirt in the tip
away from the regulators. Before relighting passage causes obstruction and back-
the blowpipe, it is advisable to examine the fires.
various pieces of equipment for possible
damage caused by the flashback. 5. A hot tip may be caused by a series of
backfires, or by working in deep grooves
Should a flashback travel back very rapidly or blind holes. The heat in the tip preheats
and cause a fire to burst through the the gases, causing a rise in the speed of
acetylene hose. close the acetylene cylinder flame propagation and a rapid series of
valve immediately. backfires result. To cool the tip close the
Repeated flashbacks or repeated backfires in- needle valves, open the oxy-needle valve
dicate that something is seriously wrong with slightly and quench the torch in water.
the blowpipe or the manner of operating it. Plow out the water with oxygen. then
Shut down the entire system and try to find the relight the torch.
trouble.

143
1:128 SHOP EQUIPMENT AND PRACTICES

Causes Of Flashbacks Six main factors have to be considered when

fusion welding mild steel:
1. Grossly unequal pressures cause the
higher pressure gas to back up into the 1. Correct Size Tip
lower pressure line. and explode if the Different tip sizes (Figure 1-236) are
pressure and mixture are right. manufactured according to the different
2. Mildly unequal pressures along with an heat requirements of various thicknesses
obstruction if a tip blockage occurs. of steel. Unfortunately. the numbering
always close both needle valves im- systems for various tip sizes are not stan-
mediately. then clean the tip. dardized and therefore the recom-
mendations of different manufacturers
3 Failure to purge each line individually must be followed. Every tip size has a
before lighting the torch a torch that maximum and a minimum flame setting.
has been sitting idle for awhile. may have The preferred setting is one that delivers
an explosive mixture present in one line. maximum heat without a harsh blowing ef-
The explosive mixture could be created by fect.
the torch being bumped or dropped.
causing the needle valves to open slightly.
Any obstruction of the tip would further in-
crease the danger of this condition.
4. Faulty manipulation of valves such as
lighting a torch with both needle valves
open. or otherwise failing to operate
equipment in the recommended manner.

FUSION WELDING 2. Flame Setting

In fusion welding two pieces of metal are The recommended flame setting (Figure 1-
brought together and the edges are melted 237) is neutral although some authorities
with the oxyactylene flame. The molten metal suggest a very slight excess of acetylene.
will flow together with the metal of the
welding rod until each edge is completely INNER CONE
fused with the other. After the metal has
cooled. there is a single continuous piece OUTER ENVELOPE
with no seam. In fusion welding. the base
metal and the welding red generally have (1-237)
essentially the same composition.
In all oxyacetylene welding. it is essential that
the weld penetrates into the metal. With fairly
light metal up to 1/8th inch. a distance equal
to the thickness of the metal may be left be-
tween the pieces to be welded. This rule may
also be used in welding standard pipe up to.
but not over. one and one-half inches in
diameter. Where the thickness of the metal is
such that it would be difficult to secure full
penetration if the edges were simply butted
together. it is customary to bevel the edges
before welding. Placing the two beveled
pieces together forms a vee nearly through to
the underside of the pieces. Thus the weld
can penetrate right to the bottom of the joint.
Welding or filler rods used in fusior welding
vary in size from 1/16th to 3/8ths inch in
diameter. Filler rods are made from first grade
steel with deoxidizers added and are gover-
ned under various specifications. e.g.. ASTM.
ASME. CSA.

444
 SHOP EQUIPMENT AND PRACTICES 1:129

3. Torch Angle 5. Speed Of Travel and Movements

Depending on the requirements of heat The speed of travel depends on the heat
and penetration. the torch may be held at requirement. The faster the torch is moved
an approximate angle of 45° for puddling forward the less the heat will go into the
or fusion without a filler rod (Figure 1-238). steel. Generally speaking, for forehand
For the penetration necessary for full welding the speed should be such that the
strength butt joints, the angle of the torch inner cone will be at the leading edge of
Should be between 60' and 80', and the puddle (Figure 1-240). For small,
Sometimes even 90' for flat position work. narrow beads the motion will have an oval
The steeper the angle the deeper the pattern. In some cases where a wide weld
penetration. If one side is heavier, the bead is required, the torch may be moved
angle should be such as to bring both from side to side in semi-circular motions.
sides to the melting temperature at the alternating with the rod. For backhand
same lime. welding the torch is held at the front of the
puddle and may be moved straight back
and forth.

--
APPROXIMATELY 45'

i=
APPROXIMATELY 90
FILLER /
ROO
LEADING EDGE

PUDDLE DEPOSIT

'1505333:Vc
(1-238) DIRECTION OF TRAVEL

4. Distance Between Work and Flame

The hottest point of the flame is ap- FILLER ROD MOTION
TORCH
proximately 1/16th inch in front of the in- MOTION
ner cone (Figure 1-239). If the cone is
touched against the puddle the metal will
carbonize and may become porous. On
the other hand, if the cone is too far away,
.4_
FOREHAND TECHNIQUE
the effect of the protective outer envelope
will be reduced and unnecessary
oxidation (burning) might take place. MOTIONS
BACK AND FORTH
FOREHAND TECHNIQUE

BACKHAND TECHNIQUE

mom (1-240) WELDING TECHNIQUES

DISTANCE OF CONE 1/16" 1/8"

(1-239)

145
1:130 SHOP EQUIPMENT AND PRACTICES

6. Operator Comfort and Position

The operator must position himself com-
fortably, as this will enable him to produce
the same high quality deposit in minimum
time. even after many hours of work.
Note: ALWAYS MELT THE PUDDLE
FIRST. THEN ADD THE FILLER
ROD.
Weldfaults
Weldfaults are illustrated in Figure 1-241.
1. Lack of penetration:
(a) Land too heavy
small.
root opening too
( 1->

(b) "V" too narrow.

(c) Insufficient heat.
Tip too small.
Flame too small.
(d) Speed too fast.
The faster the speed the less
heat goes into the metal. (e) tcri
(e) Flame too far away from
base metal.

2. Lack of fusion:
(a)

(b)
insufficient heat.
Tip too small.
Wrong angle of torch.
=11
(c) Improper manipulation. (b)

(d) Filler rod too large.

(e) Filler rod melted firt.

(1-241)

146
 SHOP EQUIPMENT AND PRACTICES 1:131

3. Poor appearance.
(a) Improper manipulation.
Uneven distance of flame.
Irregular torch and rod movement.
(b) Wrong flame setting
Result of oxidizing or reducing flame.
(c) Insufficient heat.
(d) Dirty surface (oil paint. etc.).

4. Crystallization (coarse grain structure).

(a) Overheating.

5. Undercut and overlap.

-\=
(a) Improper torch angle.
(b) Excessive heat and/or
insufficient filler material.
(c) Puddle too large
(does not solidify in time). TORCH POSITION
(d) Base metal too hot
(puddle does not solidify in time).
(e) Incorrect torch and rod manipulation.

6. Porosity great number of small gas

pockets.
(a) Dirty surface (oil. paint. etc.) ROD POSITION
produces gases.
(b) Speed too fast. Gases cannot escape.
(c) Improper torch and rod manipulation.
insufficient puddling.
(d) Touching inner cone to puddle.
(e) Improper flame setting. reducing or
oxidizing flame.
(1) Excessive heat (boiling puddle).

7- Cracks in welds surface. internal.

longitudinal. transverse. crater and hair
cracks.
(a) Joint too rigid.
(b) Faulty preparation. restrained weld.
(c) Weld stressed while in blue brittle
range
(d) Brittle base metal.
(e) Lack of preheat Of required).
(f) Secondary faults such as lack of
penetration or fusion. porosity. hair (1-241)
cracks. etc

147
1:132 SHOP EQUIPMENT AND PRACTICES

Fusion Welding Of Cast Iron 8. To avoid hard spots in cast iron:

Equipment needed: (a) Never add cold rod. Always heat the
rod end before adding to the puddle.
A tip at least as large as would be used
on steel of the same size and (b) Never allow the cone of the flame to
thickness. Use a neutral flame. touch the puddle.
Cast iron rod. There are two types: (c) Use only enough flux to keep the
"Fusewell #11" rod for plain castings. puddle clean and free flowing. Too
and "Fusewell Alloy #66" rod for much flux is just as bad as too little.
higher grade alloy castings. (d) Avoid any rapid heating or cooling.
Cast iron welding flux such as Rapid cooling could occur from
Hematox. drafts or by lust laying completed
castings on cold plate.
Welding Procedures
9. Whenever possible try to make the weld
1. Prepare the break up to a 90' included in one pass. Working slightly up grade
angle. Tracers. small sections of the will assist in flowing heavier beads, but
original break not removed in due to the high fluidity of the cast iron
preparation are recommended to align puddle, cast fusion welding is only done
the work. The tracers are later melted in. within the limits of the flat position. A
helper handy with tongs can make the
2. Align and tack the work securely. job easier. He should be able to an-
3. Support the work to prevent it from ticipate the welders needs.
sagging while hot. Where more than one pass is required to
4. Totally preheat intricate castings to a full fill the groove. it is necessary to even out
red temperature. Small simple shapes the temperature right across the joint
may be locally preheated red, but be sure before starting each subsequent pass.
to raise the temperature slowly, evenly Otherwise cracking of the root bead at
and right across the weld area. Local the starting point will occur. The
preheating should be fairly wide and full cracking may not be visible to the naked
red. eye. but on a break test a dark colored
oxidized section makes it obvious that a
5. With a neutral flame, heat the rod end crack existed.
and dip it in the flux. Then heat the start-
ing point until a water puddle is formed. 10. Keeping a temperature even. flow in weld
ends and build them up if necessary.
6. Add the rod by stirring the rod end in the Build up should not exceed 10% of the
bottom of the puddle to loosen the thickness of the material.
oxides. Let the oxides float to the sur-
face. Oxides appear as white spots under 11. Total post heat intricate castings to a lull
the flame and if left will cause pinholes red heat. Once again take precautions
or blowholes. Often pinholes do not show against sagging. Cooling should be as
up until the second pass is being made. slow as possible. It may be done in the
In this case slowly lower the torch, cup- oven. by tightly closing all openings to
ping the molten puddle, and follow the retard cooling. or slow cooling may be
pinhole down till the oxide appears. Flick accomplished by burying the casting in
it loose with the fluxed end of the rod. slaked lime, dry ashes, or dry sand.
float it out, and slowly raise the torch Even simple shapes should be post
allowing the cupped metal to flow in- heated and slow cooling is essential.
ward. If the torch is raised quickly the
metal rushes in and may trap gases 12. Where welds are to be machined. the ap-
causing further pinholes. plication of monoclinic stick sulphur or
bar laundry soap to the hot weld area im-
7 Work the puddle not only by stirring the mediately prior to burying will promote
rod. but also by circling the torch or by softness and good machinability.
moving it from side to side, always
watching for oxides and pinholes.

148
 SHOP EQUIPMENT AND PRACTICES 1:133

BRAZE WELDING In some cases where brass or bronze is to be

joined to iron, steel, or copper, only the brass
In a true braze weld. the parent metal does not or bronze side of the joint will melt. However,
melt during the welding process. The joint is the joint is still referred to as a braze weld.
properly prepared and cleaned. then heated to
a point where the grain structure opens up The metals to which bronze will adhere with
and tinning or amalgamation takes place satisfaction are: irons and steels (except
(Figure 1-242) The tinning process is similar those high in nickle or chromium such as the
to soldering, with the exception that tobin or stainless group), copper, brass and bronze.
manganese bronze is used as a filler metal Bronze will not take to non-ferrous materials
and of course the heat is considerably higher, such as nickle. Advantages of braze welding
usually in the dull red to medium red range. are:
On the other hand. where brass or bronze is 1. Where less heat is used, there will be less
joined using bronze rod, the joint is a true warpage or distort ion.
fusion weld. Both sides of the joint melt and
flow in with the tiller maw to form the weld 2. Braze welds tend to be much lower in
(Figure 1-242). residual stress.

BRONZE 3. Dissimilar metals may be easily joined

using the brazing process.
STEEL OR COPPER 4. Joints up to 60,000 psi tensile strength are
CAST IRON
possible.
5. Braze welds offer some joint flexibility or
give.
6. The process is quick, clean and relatively
cheap.
Braze welding id not used (rather. fusion
welding is used):
BRONZE 1. When the work is subjected to intense
heal. such as in the case of exhaust
STEEL
vi BRONZE
manifolds and lines on gasoline engines.
Bronze is weak when too hot and will
break down.
(1-242) BRAZE WELDS
2. Where the work is subjected to alkali
corrosion.
3. Where color match is essential.
4. Where rigid joints are required, since
bronze has some give to it.
5. On second or third repairs when braze
weld has originally been used. You can't
trust old braze weld a visual inspection
will tell you nothing about the weld.

149
1:134 SHOP EQUIPMENT AND PRACTICES

Braze Welding Procedures

Cast iron and malleable cast iron have by far
the narrowest tinning range. Slightly too cold
and tinning is shallow and weak. Slightly too
hot and surface acids hinder or prevent tin-
ning The information here deals with braze
welding cast iron. although the braze welding
of other metals is similar. with the following
exceptions:
E The type of flame used and the type of flux
used will change with the metal being
brazed as the following table shows:

Metal To Be Joined Flame Type Flux Type'

Cast iron, malleable cast iron Slightly carburizing "Braze Weld"

or coated rod

Wrought iron and steels Slightly carburizing "Copox" or

to neutral coated rod

Galvanized iron and copper Slightly oxidizing "Copox" or

coated rod

Fusion of brass or bronze Slightly oxidizing "Copox" or

coated rod

'Note: Generally, coated bronze rods Joint Preparation

have a universal type of flux. This
IS handy for most brazing jobs. Since the strength of a braze weld depends
but in heavy bronze build up entirely on the amount of properly tinned joint
work, it is often wise to go to bare surface, the use of wide Vee"s is recom-
bronze and add flux sparingly mended, A 90° included angle should be con-
after the first layer has been sidered a minimum (Figure 1-243). The
deposited. Don't use too much shoulders of the joint should be cleaned back
flux as it can cause problems in so bronze may flow over the shoulders, Weld
machining the work. When bare ends should be cleaned to the full bead width,
rod is used, dip the heated end of so they can be floated over with bronze,
the rod in the flux pot to pick up Double-V preparation is. of course, better than
the needed amount of flux. When
single-V, but if the latter must be used. round
off the root of the joint and clean back the un-
more is required, dip the red
again.
der surface so the bronze may flow through
the root and spread on the underside (Figure
2. Only cast iron and malleable cast iron will 1-243).
require searing with an oxidizing flame to
remove carbon smear. Where cast iron
surfaces have been prepared by grinding,
the free graphite in the cast iron smears
across the ground surfaces, and retards
tinning action. Since oxygen has an af-
finity for carbon, the oxidizing flame
quickly removes this smear. Care should
be taken in searing, not to oxidize the
metal surfaces. At the first sign of any
DOUBLE-V PREPARATION
temper colors such as straw yellow, stop
the searing. (1-243)

150
 SHOP EQUIPMENT AND PRACTICES 1:135 1

When preparing a joint sharp corners and 2. Sear joint surfaces with strongly
edges should be avoided as they tend to oxidizing flame to remove carbon smear.
overheat and oxidize. Once oxidized they will Do not overheat the work so the ground
not tin properly and the joint will be weak. surfaces are discolored. Sand blasted
surfaces or chipped grooves, are best.
The use of fluted joints will further increase but grinding is more common.
tinning surface, but again avoid sharp edges
(Figure 1-244). 3. Align and tack the work securely.
SHOULDER CLEANED BEYOND 4. Support the work adequately to prevent
THE VEE sagging. Intricate castings should be
totally preheated to a grey color. Even
simple shapes should receive a local
slow even preheat right across the entire
joint area.
5. Slightly carburize the flame (11% times)
to neutral. Hold it back from the work.
and keep it moving to promote even
SINGLE VEE ROOT ROUNDED AND
PREPARATION CLEANED BACK
heating. Bring the joint temperature at
starting point to a red dull.
6. Put a drop of braze (with flux) on the
work and watch the reaction.
(a) If the drop of bronze flows quickly.
evenly, and smoothly, with little or
FLUTED JOINT SURFACES no fuming. the temperature of the
work is approximately right.
(b) If the work is too cold. the bronze
drop sits like a ball. and refuses to
flow. Add further heat around the
drop of bronze till it spreads and
flows evenly. Do not add heat on the
(1-244) JOINT PREPARATION bronze drop as it will burn quickly.
giving off a puff of white zinc-oxide
Braze Welding Cast Iron fumes. which normally would mean
1. Properly prepare the joint. The use of too much heat. In this case.
(r :cers is recommended to help in however. its the bronze drop that is
aligning the parts of odd shaped pieces. too hot. and the work is still too
Since cast iron does not take a per- cold. When good smooth even flow
manent bend belore it breaks. the pieces is established. the tinning tem-
may be fitted back together on the perature has been reached.
breaks and proper alignment is assured
(Figure 1-245). Tracers should be small (c) If the work is too hot when the
enough to tin through. bul not small bronze is added. a puff of white
enough to oxidize or burn. fumes appears. often accompanied
TRACERS ON BOTH by blue flame in the puddle. The
PIECES FITTED bronze flows very quickly and
TOCF YHER
unevenly, leaving islands of oxides
that refuse to tin. The oxides appear
as white spots under the flame. Sub-
SHOULDERS sequent passes of d metal will
CLEANED cover these spots biAt they still are
BACK not tinned and they seriously
weaken the joint. Where
overheating occurs, reclean the sur-
faces. removing the oxides.
ENDS CLEANED

(1-245) JOINT PREPARATION

151
1:136 SHOP EQUIPMENT AND PRACTICES

7. When the tinning temperature is

reached. add the rod almost continuously
by circling or moviflg it from side to side.
At the same time keep the torch moving
to promote even heating and to prevent
burning of local areas.
If the work shows signs of becoming too
hot
(a) Reduce the heat slightly.
(b) Inline the torch more towards the
rod to melt it faster. The weld will
progress faster and lessen the heat
put into the work.
(c) Hold the torch slightly further away
from the work to lower the tem-
perature.
If the work shows signs of being too
cool. remove the rod for a short period of
time or increase the heat.
8. Wherever possible try to make braze
welds in one pass. Tinning. filling. and
beading should progress simultaneously.
Working up grade will assist in flowing
heavy beads.
if more than one pass is required to com-
plete ice weld. the first pass should seal
the root and completely tin the loin% sur-
faces. otherwise oxides will form on the
untinned areas Subsequent passes be-
come bronze (own welding and the
flame should be changed to slightly
oxidizing to both reduce fum:r.g and the
tendency of the bronze to become
spongy
9. In completing the weld, be sure to float
Over weld ends. thus eliminating ,notch-
mg.

10 Intricate castings should receive a total

post heat to dull red. Even simple shapes
benefit from post heat treatment. Allow
the work to cool slowly.

152
 SHOP EQUIPMENT AND PRACTICES 1:137

QUESTIONS WELDING 6 What is the maximum sale operating

pressure when using acetylene gas for
1. A recommended practice is to store full welding or cutting?
and empty oxygen and acetylene cylin-
ders* (a) 45 psi
(a) under cover in one common room (b) 25 psi
(b) in the open. but separated (c) 15 psi
(c) under cover. in separate rooms. with (d) 5 psi
empty and lull cylinders separated 7. In what position should acetylene cylin-
(d) Both (b) and (c) are correct ders be stored?
2 The identifying colors for oxygen and 8. Acetylene is sold by
acetylene hoses are:
(a) gallons
(a) red. oxygen: green. acetylene weight
(b)
(b) red. acetylene: green, oxygen pressure
(c)
(c) red. acetylene: blue. oxygen liters
(d)
(d) blue. acetylene: red. oxygen
9 If oil or grease contacts pure oxygen.
3 It is standard on oxygen and acetylene what is likely to occur?
welding equipment to have:
(a) right hand threads on oxygen lines 10 Tips of welding or cutting torches are
left-hand threads on acetylene lines cleaned with.
(b) lefthand threads on oxygen lines (a) special brushes
right-hand threads on acetylene (b) hot soapy water. then blown dry
lines
(c) solvent or any petroleum type
(c) right-hand threads on both lines cleaner
only hose color is used for iden- tip cleaners or tip drills
tification (d)

(d) left-hand threads on both lines only 11 True or False? Torches can be safely
hose color is used for identification relit from hot metal.
4 The regulator is a device connected to 12 Before installing regulators on cylinders,
the cylinder that high a good practice is to:
pressure in the cylinder and maintains a oil the threads
(a)
pressure
(b) crack the cylinder valves to blow
5 Pressure in a lull oxygen cylinder is 2200 out dirt
psi at 21 C As the temperature in-
creases (c) Both of (a) and (b) are recom-
mended
(a) the weight and pressure increases
13. Once gauges are installed. open the
(b) the weight stays the same and the cylinder valves first the
pressure increases acetylene. normally turn. then
(c) the weight increases but the oxygen
pressure decreases 14. Briefly explain how to check for leaks
(d) no change takes place in either the once the torch is set up.
weight or pressure
15 For fusion welding. what type of flame is
recommended?
(a) neutral flame
(b) oxidizing flame
(c) reducing flame
(d) fusion flame

153
1:138 SHOP EQUIPMENT AND PRACTICES

16. When shutting down welding equipment

which cylinder is turned off first?
17. List three signs that indicate a flashback
has occurred.
18. List the four steps in order. that must be
taken if a flashback occurs.
19. Fusion welding is a process whereby two
pieces of metal are brought together and
the edges are with the oxyac-
tylene flame.
20. As opposed to a fusion weld. in a true
braze weld the parent metal does not
during the welding process.
Only the rod does.
21. List three causes of backfire.
22. Briefly explain how flame cutting of steel
is accomplished.
23. For your safety and protection list the
necessary protective equipment that
should be worn when using oxyacetylene
welding or cutting equipment.
24. After fusion welding cast ir On the work
should be:
(a) c000led quickly
(b) cooled very slowly
(c) cooled in the air
25. When fusion welding two pieces of metal
it ts best to ____ the edges of the
metal on the weld line.
26. When preparing a Joint for a braze weld.
Viol/Its are recommended with included
angles of _______ degrees.
27. If the work is too hot when bronze
welding. spots will appear
that won't tin properly.
28. True or False? Flame cutting requires
preheating.
29. The tip selected for a cutting lob will
depend on the of the metal
to be cut.

154
 SHOP EQUIPMENT AND PRACTICES 1:139

ANSWERS - HAND TOOLS, SHOP SAFETY, 32. (b) double cut

SERVICE LITERATURE
33. Lightly drawing the file crosswise over a
1. (c) make. model. and serial number surface to finish it.
2 False 34. two
3 (b) 4 35. (b) on the forward stroke only
4. True 36, number of teeth
5 eyes. back. hands. head. feet and ears 37. (a) the handle of the vise only
6. 13 38. To protect finished surfaces.
7. (d) protect machined surfaces 39. (c) away from the handle
8. False 40. (c) 12 notches
9. internal or external 41. (c) width of the bolt head across the
flats
10. (b) reamed
42. Pull on the permanent side of the
11. False wrench. not on the adjustable side.
12. (b) 8 to 12 43. (b) 1/16th inch
13. (d) making a chisel cut on the side to 44. (c) notches
which the drill should be drawn
45. The offset allows more swing when the
14. (c) margin wrench is flopped.
15. (c) over the margin 46. The tubing wrench holds like a box
16 (a) No. 1 to 80 wrench yet is open on the end like and
open-end wrench.
17. (b) 118
47. 1. ratchet
18. (a) a tap cuts threads in a hole. and a 2- flex handle
die cuts threads on a rod 3, speed handle
4. universal joint
19. (b) taper. plug. and bottoming
5. extension
20. (b) alter a taper tap 48. (c) safeguard on over stressing parts
21. (b)
49. (d) 5 feet-pounds
22. (c) drill a pilot hole 50. reach and spread ....
23. Do not turn it backwards. 51. (d) 7 to 10
24. (c) planetary gears
52. (b) the shortest legs possible
25. cold chisel, cape chisel. round nose 53. ... tinned ....
chisel and diamond point chisel
54. To clean the meta' of oxides and help the
26. (c) file cuts solder fuse the metals.
27. center. starting and pin (a) resin flux
55.
28. common, phillos, clutch head and offset 56. (b) heli-coil
29. rubber. brass. plastic and rawhide
30. combination. needle nose. vise grip and
diagonal
31 (c) rough or coarse-cut file

. 155
1:140 SHOP EQUIPMENT AND PRACTICES

ANSWERS AIR, ELECTRIC AND

HYDRAULIC POWER TOOLS
1. (b) 1/16"
2 True
3. . . cool.
4. The drill press has greater accuracy.
5. . . overtighten . . ..
6. Know how they come apart.
7. Puller. pump and reservoir. and adapter.
8. The 3/8th inch is faster than 1/2 inch. but
has less torque.
9 False

156
 SHOP EQUIPMENT AND PRACTICES 1:141

ANSWERS MEASURING TOOLS

1. (b) steel rule
2. (a) 3.890 (b) 5.370 (c) 3.375

3. 1. anvil
2. frame
3. spindle
4. lock
5. ratchet
6. thimble
7. barrel
4. (b) between three and four inches
5. (c) 3.187
6. (a) 3.812
7. (a) .812 (b) .770 (c) .665
(d) .875

8. (a) 2.80 (b) 5.04 (c) 10.5

(d) 10.33
9. (a) .187 (b) .246 (c) .340
(d) .125
10. (a) 22.65 (b) 19.29 (c) 15.00
(d) 15.34

11. (b) telescoping gauge and outside

micrometer
12. (b) diameter of a hole
13. True
14. (c) go-no-go gauge
15. (d) cut oil to remove damaged portion

157
1:142 SHOP EQUIPMENT AND PRACTICES

ANSWERS FASTENERS
1, (a) slash marks
2. The distance from under the head to the
end of the threadeo part.
3. (c) diameter of the bolt or screw
4. (b) number of threads per inch
5. (c) the grade
6. Three slashes indicates grade t..
7. (c) the number of threads per inch
8. (c) nuts
9. (c) screws
10. (d) a cotter pin
11. False
12. (c) across the flats on the head
hex head bolt 3
plow bolt 9
hex socket head 5
12-point head bolt 2
hex nut 6
castle nut 8
lock washer 10
lock nut 4
flat washer 1

slotted nut 7

14. striking wrench, cutting torch. nut split-

ter. hacksaw and penetrating oil
15. A woodruff key sits deeper in a shaft
thereby giving more support.
16 False. Tighten it.
17. False Bend it against one flat only.

158
 SHOP EQUIPMENT AND PRACTICES 1:143

ANSWERS HOSES, PIPES, TUBES,

FITTINGS AND ADAPTERS
t. (d) 1/16th of an inch
2. (a) decreases
3. (c) the length up to the notch on the fit-
ting socket
4. (d) an of the above
5. (b) have different seating angles and
thread pitches
6. The galvanizing may flake off and con-
taminate the system.
7. Because it becomes brittle when sub-
jected to heat and will break at the flared
joints.
8. (b) OD alone
9. (c) ID and wall thickness
10. iron pipe fitting 2
solderless compression fitting 1

inverted flared fitting 5

double compression fitting 4
SAE flared fitting 3

159
1:144 SHOP EQUIPMENT AND PRACTICES

ANSWERS LIFTING AND BLOCKING

1. Cranes. forklifts and jacks.
2. The lifting capacity of the equipment
must be clearly marked on it.
3. Block the vehicle with approved
blocking or stands.
4. If only one link is weak a chain can
break, whereas many strands of wire
must break before the wire rope would
break.
5. Chains cannot kink and will more easily
take the shape of the object being lifted.
6. Increase.
7. ... 45 degrees.
8. False
9. (c) the diameter of the material in the
bow
10. (d) a pipe sleeve and washer are used
to support it and prevent it from bending
11. (b) one and one-half times the bolt
diameter
12. (d) both (b) and (c) are correct
13. ... stands and square wood blocks.
14. ... bridging.
15. In the service manual.
16. (c) discard the chain
17. cracks
nicks. gouges
stretched links
bent. twisted links
worn links
18. Protect the wire rope with blocking or
pads.
19. False
20. ... shackle.

160
 SHOP EQUIPMENT AND PRACTICES 1:145

ANSWERS -- WELDING 22. A jet of pure oxygen from the cutting

torch is directed against the heated steel
I. (c) under cover. in separate rooms, with
causing rapid oxidation and combustion
empty and full cylinders separated
of the metal.
2 (b) red. acetylene: green. oxygen 23. goggles
3. (a) right-hand threads on oxygen lines leather gloves
left-hand threads on acetylene lines leather apron. if available
4 ... reduces ... constant working 24. (b) cooled very slowly
pressure. 25. ... bevel ....
5. (b) the weight stays the same and the 26. .. . 90 degrees.
pressure increases.
6. (c) 15 psi
27. ... white oxide . .

28. True
7. Upright.
8. (b) weight
29. ... thickness ...
9. An explosion.
10. (d) tip cleaners or tip drills
11. False
12. (b) crack the cylinder valves to blow
out dirt.
13. ... slowly.... half a turn ... all the way.
14. Turn on the cylinder valves. set the
working pressures. turn the cylinder
valves off. If there's a pressure drop on
the high pressure gauge. there's a leak.
15. (a) neutral flame
16. acetylene
17. squealing or hissing noise from inside
the blowpipe
sparks coming out of the nozzle
heavy black Smoke coming out of the
nozzle
18. close the blowpipe oxygen valve
close the blowpipe acetylene valve
close the oxygen regulator
close the acetylene regulator
19. ... melted ...
20. ... melt ....
21. faulty seat conditions between tip and
mixer
too little gas flow
tip too hot from being too close to the
work
dirty tip

161
1:146 SHOP EQUIPMENT AND PRACTICES

TASKS SHOP EQUIPMENT 13. Using a small hammer. snips. and hole
AND PRACTICES punches. make:

HANDTOOLS, POWER TOOLS a paper gasket (e.g.. water outlet

gasket.)
AND BENCH WORK
a cork gasket (e.g., oil inspection
1. Gain experience using the hand tools cover gasket)
and power tools discussed in this block.
an asbestos gasket (e.g., an exhaust
2. Steam clean an engine or transmission flange gasket)
so that it is clean enough to work on.
starting, using and stopping the steam
machine without assistance. MEASURING TOOLS

3. Clamp in a vise a piece of mild steel. e.g.. Using the indicated precision measuring in-
x 2", and cut a 3" piece with a strument, take the following measurements:
hacksaw. 1. With an outside micrometer. measure the
4. Clamp the 3" piece of steel with the cut throw on a crankshaft for taper and out
end up. and square the end with a file. of round to within .001" (.025 mm) of
manufacturer's specifications.
5. Select the correct size drill bit for %" NF
thread, and using a drill press, drill a 2. Using an inside micrometer. measure the
hole through the flat of the metal. bores on an engine for taper and out of
round to within .001" (.025 mm) of
6. Using a taper and then a plug tap, thread manuisc:turer's specifications.
the hole to V:" NF.
3. With a depth micrometer. measure the
7. Using a vise and hacksaw, cut a piece of counter bore depth on an engine block
1/4" round stock 6" long. to within .001" (.025 mm) of manufac-
turer's specifications.
8. Clamp the 6'' piece of round stock ver-
tically in a vise. taper its end with a file, HOSES, TUBES, PIPES,
and thread it with a '4" NF die for 2". FITTINGS AND ADAPTERS
When complete, the rod should thread in
the tapped hole (made in Task 6) with Hose and Fittings
ease.
1. Matching the correct size and type of
9. Locate a broken stud which has broken hose with replaceable fittings, make up a
at or below the surface. Using the low, a medium. and a high pressure hose.
correct drill and stud-removing equip- using the correct procedures and hose
ment, remove it without damaging the make-up tool kit or hand tools.
threads of the tapped hole.
Tubing and Fittings
10. Locate a worn hole in a casting
(preferably aluminum) and using a thread 1 Using a tubing cutter. cut a 10" piece of
restorer kit install a thread restorer 'he 5/16" copper tubing from a roll Ream
same size as the original. the ends in preparation for flaring.
11. Clean and flux two pieces of 20 gauge 2. Using a flaring tool kit. flare one end of
metal, then with a torch and solder make the tube with a single I:are. Then put two
a lapped joint. 5/16" SAE flare tube nuts onto the tube
from the end not yet flared. Make sure
i2. With a soldering iron and rosin core the nuts face the right way. Now double
solder. clean and solder two pieces of 12 flare the other end of the tube. The flares
gauge wire to form a good connection. must be straight and square with the
tubing. and be large enough to support
the fittings yet not so large that they in-
terfere with the nut or won't fit inside the
nut.
3. When the flaring is complete bend the
tubing.

162
 SHOP EQUIPMENT AND PRACTICES 1:147

Pipe and Fittings WELDING

1 Clamp a piece of 112" pipe (black or The following tasks are to be preformed under
galvanized) in a pipe vise. and using a the supervision of a qualified mechanic who
pipe cutter. cut an 18 inch piece. has a working knowledge of oxyacetylene
cutting and welding equipment.
2. Clamp the 18 inch piece of pipe in a pipe
vise and ream both ends in preparation 1. Using the cutting head attachment for
for threading. oxyacetylene equipment, make a clean,
straight cut on the metals listed below,
3 Using half inch pipe dies and cutting oil, selecting the correct size tip for the job
cut threads on both end: approximately and correctly assembling and adjusting
one inch long. The threads are ac- the tip:
ceptable if none are torn or damaged
and ii you can turn a pipe fitting onto the plate or flat bar up to one-half inch
threads three turns by hand. material
angle iron
channel iron
LIFTING AND BLOCKING H-beam iron
Do all the following lifting tasks for which the rusted iron
equipment is available to you:
Also. use oxyacetylene cutting equip-
1. Using an overhead crane with the ment to:
correct slings or chains. lift and securely
block a truck or wheel loader at a height split welded plates and brackets
suitable to allow working on the wheel cut off rivets. bolt heads and nuts
assembly. Lower the vehicle safely.
pierce bolt holes
2 Using an overhead chain block hoist with
the correct slings or chains, lift and
2. Get experience using a large rosebud
securely block a truck or wheel loader at
heating tip on jobs that require heating
to remove components, e.g., removing
a height suitable to allow working on the
press-fit parts.
wheel assembly. Lower the vehicle
safely. 3. Make a fusion weld to join two pieces of
Using an appropriate size hydraulic jack.
exhaust tubing. using the right size
3
welding tip. The joint should be gas tight.
lift a crawler tractor in the shop or in the
field and securely block it with wood 4. Make a brazed lapped joint on two
blocking or metal stands at a height pieces of gauge metal using the right
suitable to allow working on the un- size welding tip.
dercarriage. Lower the tractor safely.
4. Operating a forklift. lift several objects
such as a loaded pallet board. an engine
assembly. a track frame. Move the object
to its desired location and lower it safely.
Park the forklift and lower the forks.

163
ellmMt,

BLOCK

Moving and
Stopping Equipment

164
 STARTING, MOVING AND STOPPING EQUIPMENT 2:1

Starting. moving and stopping equipment is There are also some good publications such
part of a heavy duty mechanic's job. The as the Construction Industry Manufacturer's
mechanic must know: Association (CIMA) Mantwts that deal with
general procedures and safe practices to
1. What to check prior to starting a machine follow when moving or working on heavy
(pre-start checks). equipment. Some examples of CIMA Manuals
2. How to start a machine under varying are.
climatic conditions. Motor Grader Safe 'anual for Operating
3. How tc safely move a machine. and Maintenance Personnel
4 How to shut down a machine for both Crawler Tractor/Loader Safety Manual for
overnight and extended periods. Operating and Maintenance Personnel
(Figure 2-1)
One of the best sources of information on the
operation of equipment is manufacturer's Hydraulic Excavator Users Salety Manual
Operating Manuals. Some manufacturers
have information for the operator and the
maintenance man in one manual. where as
others supply two manuals: an Operator's
Manual and a Lubrication and Maintenance
Manual.

CRAWLER TRACTOR/LOADER

Safety Manual
FOR OPERATING AND MAINTENANCE PERSONNEL

CONSTRUCTION INDUSTRY MANUFACTURERS ASSOCIATION

111 E. Wisconsin Ave. Milwaukee,Wisconsin 53202

(2-1)
c011 1 le,'Sy (A C 01151 rtti:Ito m industry
Adlailli IA, WHIM ASSW;I:111, fil $(,IMA I

165
2:2 STARTING, MOVING AND STOPPING EQUIPMENT
Obviously it is not possible to be familiar with Fasten the safety bar on machines with
the operation of all heavy duty machines. articulated steering.
However. you should acquire and read
Operator's manuals for each piece of equip- Stop the wheels from rolling by putting
ment that you service in your shop. Find out blocks against the tires (if applicable).
all you can about the machines you work on;
the knowledge will make your job easier, and
will make you a better mechanic. This is the SAFETY ALERT
Initial experience moving a machine should SYMBOL You will see it
used throughout service and
be done under the guidance of a qualified per-
operator's manuals
son.

PRE-START CHECKS
A pre-start check is a systematic series c!
checks on engine di iven equipment prior to
starting. The checks are intended to see that To do a Pre-Start Inspection. also called a
the machine is in good. safe running con- Daily Walk Around Inspection. refer to the
dition before it goes out to do its day's work manual for the machine you are working on
Besides protecting people from injury and the Although pre-start checks vary from machine
machine from negligent damage, pre-start to machine. there are checks common to most
checks are part of a good maintenance machines. These include:
program. Any minor problems on the machine
will be noticed and can be repaired before 1. Record the service hours or miles.
they become major ones. 2. Locate. check and top up. if necessary. all
Generally. pre-start checks are the respon- fluid levels including coolant. fuel. battery
sibility of the operator. However. the policy of electrolyte. tube oil. Keep records of fluid
some companies is to have mechanics do pre- additions.
start checks to prepare the machine for its 3. It is best to fill the fuel tank at the end of a
daily shift. In any case. you should be aware
shirt to reduce condensation. Drain a
of pre-start procedures since they are'part of
small amount of fuel from the tank at the
machine maintenance. In addition. you will start of a shift to remove any water and
have to move machines. and even though you
wouldn't do as thorough a pre-start check to
sediment. Also check the water trap.
move a machine as you would to prepare one 4. Check the condition and tension of drive
for a shift. you will still make some of the belts.
checks
5. Drain air reservoirs (if so equipped).
Before beginning pre-start checks put the although this is also best done at the end
machine in the service position: of a shift.
Put all the attachments on the ground 6. Do a walk around inspection to review the
and put an hydraulic controls in machine's general condition (Figure 2-2).
neutral
visually inspect the undercarriage,
Apply the parking brake and the trans- frame and suspension for loose bolts
mission neutral safety lock. and missing parts.
Turn the ignition key to the off position. check to see that mountings of hang-
(and pull the engine stop handle if the on components are tight.
machine is equipped with one).
check for fluid leaks: lube oil. hydraulic
Remove the ignition key from the oil. coolant, fuel.
ignition switch and open the master
switch -- examine pipes and hoses for damage
or leaks and gasket joints for leaks.
Fasten a red warning flag to the canopy
upright or attach a DO NOT START check tire pressure and wheel studs.
TAG to the steering wheel

166
 STARTING, MOVING AND STOPPING EQUIPMENT 2:3

check the conde.on of working at-

tachments buckets and teeth. booms.
arms. hydraulic cylinders. blades. wire
ropes
do minor repairs and make recom-
mendations 14r map( repairs. C't
Alk
_I...2V%
i .7431:"."-....- ,///
...1.-"'t ;;;/
-------
// 14 Nt

Or ;A1
or
(2-2)
,
0
..-
.....
Courtesy of Construction Industry
Manufacturers Association (LIMA)

Some companies will make up Pre-start Check Lists for their own machines. An example is shown
below

Date

--
Model Hour Meter

I Check fuel . OK _ Added _

2 Check fan belts. OK Replace

3 Check hydraulic pump belts OK_ Replace ____

4 Check water pump belts OK Replace

5 Check hydraulic hoses for leaks or chafing. . OK Replace

6 Check hydraulic fittings and valves for leaks . OK Repair

7 Service air cleaner ... .. ........... . OK Replace

8. Service compressor air cleaner OK Replace ___

9 Check air system (Brakes) OK Repair ______
10

11
Drain air tanks

Check wheel studs

.

visually ...
.....

....
OK

OK Replace

--
---
_
12 Check for loose nuts and bolts .. . OK Loose

13 Check all welds . OK Repair

14 Check electrical system .. OK _______ Repair _.

15 check operating controls OK . Repair

167
2:4 STARTING, MOVING AND STOPPING EQUIPMENT

Following are two examples of manufacturer's WALK AROUND INSPECTION

Prestart or Walk Around Checks The first is
for a hydraulic excavator. and the other is for HYDRAULIC EXCAVATOR
an off-1»ghway dump truck For further exam- (Caterpillar)
ples check operator s manuals at your shop
For maintenance and operator personnel
safety. and maximum servicl life of the
machine. make a thorough wa:l. around in-
spectiOn when doing lubrication and main-
tenance work Inspect under and around
machine for such items as loose or missing
bolts. trash build-up. oil. fuel or coolant leaks.
ENGINE COMPARTMENT condition of bucket. teeth and tracks
Inspect for oil and fuel leaks
and trash build-up.
SPROCKETS
Inspect for wear.

Z:701!
HYDRAULIC SYSTEM C Mil COOLING SYSTEM
Inspect leaks, worn Inspect for teaks, worn
hoses or damaged lines. riff uses and trash build-up.
%"---"'."-.1 . Observe coolant level.
COVERS AND GUARDS - U 4

Inspect for dam..ge . INDICATORS AND GAUGES

or looseness. Inspect for damage.

TRACK ROLLERS IDLERS

Inspect for wear or Inspect to; wear or
leaks. leaks.
SWING DRIVE
COMPARTMENT
Inspect for leaks. TRACK
Inspect for broken or
missing shoes or bolts.
SWING GEAR
COMPARTMENT
Inspect for leaks.

r.
J.
M..
OPERATOR'S COMPARTMENT
Inspect for loose items and
cleanliness.

BUCKET
Inspect for wear
or damage. BUCKET TEETH
Inspect for worn,
damaged, or missing
teeth.

Courtesy 01 Caterpillar Tractor Co.

168
 STARTING, MOVING AND STOPPING EQUIPMENT 2:5

Ten hour service procedures for the excavator

are given below

ITEM SERVICE
EVERY 10 SERVICE HOURS OR DAILY
C) Radiator Observe coolant level
® Air Cleaner Precleaner Inspectclean
C) Engine Crankcase Inspect oil level
® Fuel Tank Drain moisture and sediment
® Warning Systems Test

OFF-HIGHWAY TRUCK
(Wabco)

.t
[Ji

BODY
FENDERS
NOT SHOWN

Courtesy of Wabco Construction and

Mining Equipment
10 HOURS SERVICE CHECKS (2-4)
5. Tires Check for proper inflation
1 Shutters Check for proper operation pressures. (36:00 -51. 42 ply. Front and
01 shutter control. Rear 55 psi: 33:00-51. 50 ply optional.
Front and Rear 70 psi.)
2 Radiator Check level of coolant.
Capacity 120 gallons. 6. Fuel Tank Drain condensation from
fuel tank at drain cock near bottom 01
3. Fan Check for proper operation of fan
tank. Capacity 500 gallons.
and condition of fan belt.
7 Brake Fluid Reservoirs Check !eve,
4 Wheels Check wheel mounting bolts Fill with SAEJ1703 hydraulic brake fluid.
for proper torque 270±25 ft. lbs.
Capacity 2.5 pls. Sub-zero temperatures
torque
use SAE-J17028.

169
2:6 STARTING, MOVING AND STOPPING EQUIPMENT

8. Mr Starter Lubricators Fill to oil level. Stopping a diesel engine can be more dif-
Type Oil SAE-WW. ficult. A diesel fires its fuel by the heat of com-
pression (see Block 7. Engines). Once the
9. Turbo-Chargers Check for leaks. engine is cranked and fuel is supplied to the
vibration or unusual noise combustion chamber (assuming temperature
10 Crankcase Check oil level Capacity conditions are right). the engine will start. The
with fillers 40 gal : without filters 37 gal. only way the engine can be stopped is (1) by
shutting off the fuel (2) by cutting off the air or
11. Fuel Filter Drain condensation from (3) by de-compressing the cylinders (on some
filter engines).
12 Fuel Strainer Drain condensation The speed of a diesel engine is controlled
from filter. strictly by the amount of fuel delivered to it.
All diesel engines have a governor that sen-
$3. Air Reservoirs Drain condensation ses engine RPM's and controls. through
from all reservoirs. linkages. the amount of fuel delivered to the
14 Air Cleaner Check service indicators cylinders. thus preventing the engine from
on dash panel. Service filters if indicator over speeding. The governor limits the
shows red when engine is shut down. maximum RPM's to an amount safe for the
engine. The throttle position controls the
RPM's within the governor setting.
STARTING AND MOVING EQUIPMENT
For normal engine shut down. either the throt-
Once pre-start checks have been made. the tle is moved to the No-Fuel position or the fuel
engine can be started. The points below are is shut off by an electric solenoid control
common to starting and stopping all heavy valve. In either case there should be no
duty vehicles and are discussed in order in problem in stopping the engine. However.
the rest of th's block. should a fuel system malfunction during start
Emergency shut down procedures. up or while the engine is running. excessive
fuel feeding could cause an uncontrolled
Starting procedures to include the safe speed increase in the engine. Such an RPM
use of cold starting devices. increase can happen in seconds, and if
emergency procedures are not taken im-
After start checks. checking
e.g.. mediately. the engine will over speed to
gauge readings and warning devices destruction. If the malfunction is in the gave:
and testing brakes. nor. it may not be possible to cut off the fuel
Safely moving the machine and safely supply. The other alternatives left are to cut
operating the working attachments. off the air supply or to decompress the cylin-
ders.
Stopping and Safe parking.
Some engines, for example Detroit Diesel.
Procedures for extended shut-down or have an emergency shut down device that
storage. cuts ol the air supply to the engine. A flapper
valve ;Figure 2-5) is located in the air inlet of
Safe practices when working on or the engine and is operated by a cable at-
around machines with articulated tached to the control panel. Pulling the con-
steering
trol reeeases a catch. allowing spring pressure
to close the flap and shut off the air supply. If
EMERGENCY SHUT DOWN PROCEDURES
the engine has reached a runaway speed. the
Before you start a machine. know how to stop flap may not stop the engine but will slow it to
it. A gasoline engine can be stopped by sim- a point where you can safely get near and
ply turning off the ignition switch. Since the disconnect the fuel line. Note that the flapper
engine is fired by spar ignition and the valve is to be used for emergencies only and
ignition switch controls current flow that not for normal shut down: regular use of it can
creates the spark. turning the switch off slops damage seals within the scavenge blower.
the engine

170
 STARTING, MOVING AND STOPPING EQUIPMENT 2:7

1. the engine overheats

2. the oil pressure becomes low
3. the engine overspeeds (Only on some
sentinel systems. One manufacturer's
signal device actuates when the engine
reaches a speed that is 18% greater than
full load speed).
Remember. a runaway diesel engine is a
dangerous and frightening thing to be near.
Know how to stop one.

STARTING PROCEDURES, COLD STARTING

AIDS AND STOPPING PROCEDURES
SAFETY POINTS ON STARTING
Your safety and the safety of these around you
depends upon your using care and judgment
(2-5) FLAPPER VALVE in the operation of equipment. Know the
Cearpsy of Detroit IDoeSQ1 General MotorS Col Potation positions and the functions of all controls. All
equipment has limitations. Understand the
The other method of stopping the engine is by speed, braking. steering. stability and load
decompressing the cylinders Some engines characteristics of the vehicle before starting
are equipped with a decompression to operate it
mechanism which lifts either the intake or the
Before moving a machine. or its attachments.
exhaust valves from their seats. The be sure people in the area are clear of the
mechanism is an erig.ne starting aid. but in an
machine Walk completely around the
emergency it can be used to stop the engine.
machine before mounting it. Sound the horn.
Service manuaM will recommend that decom-
pression mechanisms not be used to stop an If the engine is to be started indoors. ensure
engine especially not at high RPM's but in proper ventilation to remove deadly exhaust
the event of a runaway engine anything is bet- gases.
ter than letting the engine destroy itself. On a Never leave the machine unattended with the
regular basis. though. do not use the com- engine running.
pression release to stop the engine because STARTING PROCEDURES, INCLUDING
this couid result in the push rodF, being pulled SAFE USE OF COLD STARTING AIDS
from their sockets and also cause extensive
wear on the balls and sockets Manufacturers have specific procedures to
follow when starting their engines. Some o
Precautions must be taken when starting a the concerns when starting an engine are:
diesel engine after it has been shut down for a
period of time. o.' after it has been overhauled. maximum cranking time to avoid
because there is a danger of these engines damage to the starter and its com-
running away The best precauttne is to get a ponents.
piece of smooth plywood larger than the in.
take manifold opening Leave any piping off desirable RPM upon start-up (i.e.. not to
and have the plywood ready to cover the idle or not to over rev.) to give tube oil
manifold opening to cut :he air supply in case a chance to reach all the vital areas so
the engine races Poss.bly it won t be needed. that engine parts are not damaged by
but in the event that it is you'll be prepared lack of lubrication.
Don i take chances cold Starting aids' should be used
Diesel engine sentinel Systems should be safely so that internal engine parts are
mentioned here Although they are not. not damaged
technically speaking. emergency shutdown Why do diesel engines require cold starting
oevices they are related Sentinel systems are aides/ Basically. there are Iwo reasons:
signal devices which automatically (through
an electric solenoid control) cut off the fuel I Ignition of the fuel in a diesel engine is
supply or move the Wet control to the no-fuet accomplished by heat of compression
position 11 When the temperature drops below 10 C

171
2:8 STARTING, MOVING AND STOPPING EQUIPMENT

(50 F.). compression may not be able to 3. Applying an ether starting kit (Figure 2-7).
bring the cool air to a high enough tem- The kit has mounted on the control panel
perature to ignite the fuel. a hand operated pump that injects ether
vapor directly into the intake manifold.
2 The diesel fuel itself is less volatile in cold The ether capsule in the kit is good for
weather and therefore harder to start several starts and then must be replaced.
Two common types of starting aides are used
with diesel engines:
1. Ether
2 Pre-Healer or Glow Plugs

ETHER
CAUTION, ETHER CAN BE DANGEROUS
Never handle ether near an open flame
Do not breathe the fumes
Do not use excessive amounts of ether.
Too much ether will cause unusually high
pressures and detonation which can
severely damage engine parts. Use ether
sparingly.
Ether must never be used when the electric
Glow Plug 's on (Manifold Type).
Ether is used as a starting aid because it is Air Box Fiteng 4 Piercing Tool
very volatile and readily combustible. It is 2 Capsule 5 Cap
taken into the combustion chambers with the 3 Tubing 6 Pump
air. Three methods of using ether are.
(2-7) ETHER-STARTING KIT
1. Pouring a small amount of liquid ether on
Courtesy of Detroit Diesel. General Motors Corporation
a rag and holding it near the air cleaner
inlet while the engine is turned over (takes PRE-HEATER AND GLOW PLUGS
two persons).
A pre-heater in the intake manifold (used in
2. Spraying a small amount of ether into the relation with a pump and atomized fuel) or
air cleaner intake while turning the key to glow plugs in precombustion chambers heat
the start position (Figure 2.6). the air that is taken into the combustion
chambers to aid in starting.
CAUTION: Never use ether with a pre-heater
or glow plugs because severe in-
jury can result from the ether ex-

a ploding. Use one starting aid. not

both.
ENGINE Ob. AND THE BATTERY
IN COLD STARTING
.14
E Two other factors that effect cold Starting are
the oil and the battery:
OH a lighter engine oil. or an oil with lower
viscosity. is used in winter weather. Lower
viscosity od makes the engine easier to turn
MUM over at colder temperatures.
(2-6) ETHER SPARY APPLICATION Battery Probably the most important point
Courtesy 01 Cummins Engine Co
in cold weather starting is to make sure the
battery is fully charged. Not only does a bat-

172
 STARTING, MOVING AND STOPPING EQUIPMENT 2:9

tery have a harder job to do in turning over an COLD WEATHER STARTING

engine in cold weather. but also it is not as ef- When Colder than 5°C (40°F)
ficient at lower temperatures. For example. a
fully charged battery at -9°C (15 °F.) IS Detroit Diesels are not equipped with cold
capable of delivering only 70% of its rated weather starting aids. it is recommended that
current In addition. keep the terminals clean starting fluid (ether) be sparingly sprayed into
and the connections tight. Dirty or loose con- the air cleaner intake as the engine is being
nections offer high resistance to battery started An alternative to hand-spraying the
current (Batteries are discussed in detail in ether is to install an ether starting kit. See the
Block 9 Electricity). service manual for directions on how to use
the starting kit.
Below are examples of procedures for start-up
(including the use of cold starting aids) and SHUTTING DOWN A DETROIT
shut down on three common engines that are DIESEL. ENGINE
used in a number of different machines It IS important that the engine be idled for
Detroit Diesel. Cummins Diesel. and Cater- three to five minutes before shutting it down
pillar Diesel. The starting and stopping to allow the lubricating oil and water to carry
procedures discussed for these three engines heat away from the combustion chambers.
probably cover those for most other diesel cylinder head. bearings, and shafts. Residual
engines.
heat left alter the engine stops can damage
DETROIT DIESEL many parts ranging from valves to fuel pumps.
(taken from a Clark-Skidder manual) In addition. the physical stresses from heat
expansion and contraction can cause distor-
NORMAL STARTING
tion. permanent warping. and gasket failures.
CAUTION Walk around the machine. Make It is a good practice to idle any engine long
certain that no one is in the enough to gradually reduce extreme
danger area before entering the operating temperatures.
operator's compartment.
To shut down a Detroit Diesel turn the ignition
1 Set directional shift lever in NEUTRAL. switch off. and then pull tt.e standrd engine
stop control (Figure 2-81. This operation cuts
2 Depress and release accelerator to reset off the fuel supply. Hold the stop control out
governor throttle control lever in IDLE until the engine stops operating. After the
position. engine IS stopped. move The control back to
3. Turn ignition switch on: rotate key to start
its original position.
position. and very lightly depress ac- If. after pulling the standard engine stop con-
celerator to feed additional fuel. Operate trol. the engine continues to operate. the
cranking motor no more than 30 seconds emergency engine ,top (Figure 2-8) must be
at a time to avoid overheating motor. used. By pulling the emergency engine stop
If engine fails to start. wait control, the air supply to the engine is out off
CAUTION.
until cranking motor stops thus choking and stopping it.
rotating before repressing
starter switch. Serious
damage to the cranking
motor may result if this
precaution IS not complied
with. If engine fails to start
after lour periods of
cranking. refer to Operation
and Maintenance Manual of
engine manufacturer
4 After engine starts. check oil pressure
gauge II no pressure IS indicated within
15 seconds. shut down engine Im-
mediately and determine cause.
5 Allow engine to reach operating tem- ,,-, , ,:-.,,,, 2!...-.. ,.;

perature before driving or operating I Engine Shutdown 2 Emergency Shutdown

machine. Knob (2 -8) Knob
Courtesy of !Detroit these. General Motors Corporation

173
2:10 STARTING, MOVING AND STOPPING EQUIPMENT

Whenever the emergency stop control has starting fluid is used with the
been used. it is necessary to manually reset glow plug hot. Do not use
the emergency stop cable latcharm (Figure starting fluid in any form with
2.9) at the engine air intake a preheater.
SHUTTING DOWN THE ENGINE
For the same reasons mentioned with a
Detroit Diesel. idle a Cummins Diesel for three
EMERGENCY STOP to five minutes before shutting it down. The
CABLE pre-shut down idle is especially important
LATCH with turbo-charged engines. The turbo-
charger contains bearings and seals that are
subject to the high heat of combustion
exhaust gases. While the engine is running
this heat is carried away by oil circulation but
if the engine is stopped suddenly. the turbo-
charger temperature may rise as much as
LEVER ARM 47 C (100'F). The results of this temperature
increase in the turbo-charger may be seized
TSI0177 bearings or loose oil seals.
411IMI
t2 -91 RESETTING THE LATCH HANDLE Note on idling an engine: As was just stated.
Counesy of Clark Equipment Co idling an engine for up to five minutes prior to
shut down is a good practice. However, long
CUMMINS DIESEL periods of idling are not good for an engine
because temperatures in the combustion
NORMAL STARTING chamber drop so low that the fuel may not
burn completely. Carbon from the unburnt fuel
Cummins normal start procedures are the will clog the infector spray holes and the
same as those listed for a Detroit Diesel.
piston rings. and may cause the valves to
COLD WEATHER STARTING
stick. Also. if the engine coolant temperature
becomes too low. raw fuel will wash
Cummins Diesels are not equipped with cold lubricating oil from the cylinder walls and
weather starting aides. The following cold dilute the crankcase oil Diluted crankcase oil
starting aide procedures are recommended. means that other moving parts of the engine
will suffer from poor lubrication. II the engine
I Pour three tablespoonfuls of ether on a is not being used. shut it down.
Cloth. One man holds the cloth close to
the air cleaner intake while a second man To shut down a Cummins Diesel that has an
cranks the engine. electric shut down valve. turn the switch key
to the off position. The key controls the elec-
2. Or spray a small amount of ether into the tric shut down valve and will stop the engine
air cleaner intake while cranking the unless the override button on the valve has
engine An alternative cold starting aide is been locked in the open position. In this case
a preheater. available as optional equip- to stop the engine the override button will
ment for a Cummins engine This equip- have to be manually turned clockwise. The
ment consists of a single glob. lug moun- engine can always be stopped. under normal
ted in the intake manifold, and a hand conditions. by turning this button.
priming pump to force atomized fuel into
the manilold. Depressing a glow plug CAUTION. Never leave the switch key or the
switch heats the glow plug igniting the override button in the valve open
fuel that has been pumped into the position when the engine is not
manifold thereby heating the intake air en- running. if this is done. fuel from
tering the combustion chamber. See the overhead tanks will drain into the
service manual for directions on how to cylinders causing hydraulic lock.
use the preheater. To stop a Cummins engine without an electric
CAUTION Since primary ignition takes shut down valve. turn the manual shut down
place within the manifold. valve knob.
serious damage may result if

174
 STARTING, MOVING AND STOPPING EQUIPMENT 2:11

CATERPILLAR DIESEL ENGINE Above 60° F (16° C)

These starting procedures (Figure 2-10) are
taken from an operator's manual for Cater-
pillar loader. Note the two sets of procedures
7 and 8. one for temperatures above 16 C and
one for temperatures below 16 C.

.,
6 Depress accelerator just past 7 Turn HEAT-START switch to
detent. START Release switch when
engine starts.

Below 60' F (16° C)

41111111160MIX.
I Place speed a direction con-
trol in NEUTRAL

&
6. Depress accelerator lust past 7 Turn switch to START. Re-
detent and turn switch to HEAT lease switch when engine starts.
for indicated time. It may be necessary to return
.4 Switch to HEAT until engine
runs smoothly
Starting Aid Chad

2 Engage safety lock. STARTING TEMPERATURE GLOW PLUG HEAT TIME

Above 60° F (16° C) NO
609F (16° C)-32°F (0°C) 1 MINUTE
32° F (OP C)-0° F (-18° Cl 2 MINUTES
Below 0° F ( 18° C) 3 MINUTES
* Heating of coolant and crankcase oil and starting fluid or extra
battery capacity may be required.
NOTE: if engine does not start after cranking for 10 seconds, switch
to HEAT for 30 seconds then START. If engine still does not start,
let starter cool for 2 minutes then repeat starting procedure.

(2-10) Courtesy of Caterpillar Traclor Co.

a Engage parking brake.

lk
The "Heat" mentioned is provided by glow
plugs. The Cummins Diesel just discussed
had a single glow plug in the intake manifold.
This plug ignites atomized fuel pumped in by
hand, and the burning fuel heats the air that
goes to the combustion chambers. A Cater-
pillar Diesel has a glow plug for each cylin-
der. The plugs are located in precombustion
chambers and heat the air prior to it going to
the combustion chamber.
U111111111104 .

4 Move bucket and equipment

controls to HOLD
5 Turn disconnect switch ON

175
 2:12 STARTING, MOVING AND STOPPING EQUIPMENT

The glow plugs are small heating elements.

Depending on how cold it is, they can take
from one to three minutes or longer to heat
the air sufficiently for starting. If the Cat
Diesel won't start with the aid of the glo.v
plugs then starting fluid may be used. as
directed in Figure 2.11
When Starting Fluid is Required
tv
3. Lift accelerator past detent
to stop engine.
.1
:fa

7. Depress accelerator to Just 8. Push in and turn switch to

-
past detent. HEAT for indicated time.

O
4. Turn disconnect switch OFF
and remove key.

(2-12)
A
Counesy of Catatonia' TraCtor Co.

_ -1
A ,
9. Push in and turn switch to 10. When engine starts. it may
START. and spray starting fluid be necessary to return switch AFTER START CHECKS
sparingly into precleaner while to HEAT until engine runs
cranking. smoothly. After starting the engine. some routine checks
should be made. Warm-up chetics are virtually
WARNING
use starting fluid sparingly. F4liow manufacturer's instructions carefully. the same for all engines, no matter what the
make. Below are two examples of warm -up
Never switch to HEAT when engine Is warm and running.
checks taken from Operator's Manuals.
(2-11)
Counesy of Caterpillar Tractor Co Example 1:
WARM-UP CHECKS
(Clark Equipment Company)
STOPPING THE ENGINE
Hold the engine at idle speed for ap-
proximately two minutes after starting-, then,
while the engine continues to warm-up for the
next few minutes. perform the following
checks (refer to the section. Under 250 Hours
Operations. for warm-up procedures):
1. Engine Oil Pressure Gauge 10 to 25
psi at engine idle. If less than 10 psi is
registered after 15 seconds of running.
AVvIr 1 ill shut down the engine and refer to your
t. Before stopping the engine, 2. Reduce engine speed to low engine Service Manual to correct
operate at reduced load for 5 idle for 30 seconds.
minutes and stop loader. 2. Ammeter high rate of charge to the
battery at engine start: charging rate will
decline as the charge is restored in the
batteries.

176
 STARTING, MOVING AND STOPPING EQUIPMENT 2:13

3 Mr Cleaner Indicator Check that the charger reduces oil available for bearings.
red flag indicator is not at its top position. Watch engine oil temperature or pressure
or a new filter or cleaning of this filter is gauge for a warming trend before increasing
required. Refer to the section. Under 500 engine idle RPM.
Hour Operations. for cleaning in- After a couple of minutes of idling at 600 RPM,
structions.
increase engine speed to 900 or 1000 RPM
4 Converter and Transmission Oil Tem- and continue warm-up. This procedure allows
perature Gauge 130 to 200 F is the oil to warm up and flow freely while
operating temperature. pistons, liners. shafts. and bearings expand
slowly and evenly. Idling the engine too slowly
5. Engine Water Temperature Gauge- does not allow sufficient splash lubrication of
170 to 185 F is operating temperature. cylinder walls and may result in excessive
6. Converter and Transmission Fluid wearing of pistons and liners. Idling too fast
Level checked at operating tem- during warm-up will cause too rapid and
perature as per instructions in the section. uneven expansion and also excessive wear.
Under 8 Hour Operations. Continue the warm-up until temperature
reaches at least 130 °F. (54"C), when part
Visually check for leaks at the drain and fill throttle operation is permissible. Do not
plugs in the axle assemblies. torque converter operate at full throttle until temperature is at
and transmission. and at all hose couplings least 160 'F. (71'C).
and fittings in the hydraulic. luel. air intake,
brake and cooling systems. Correct all MOVING VEHICLES
leaking conditions. and repair or replace the
gauges that are not functioning bele e con- Before attempting to operate any machine,
tinuing the operatic I of the machine. read the operator's manual and become
familiar with the purpose and use of all
Example 2: operating ontrols. Ask an experienced per-
son to show iou how to move the machine.
BEFORE DRIVING VEHICLE Then ask him to observe while you put the
(Kenworth Truck Company) machine through a trial run of its operations.
ENGINE WARM -UP When operating or moving heavy equipment.
After engine start:. let it idle while you check you shout(' be guided by some fundamental
oil pressure. air pressure and generator cwt. rules of safety that will protect you, your
put. The engine should be brought up fellow workers. and (he machine. The
following d - 'ngs taken from C.I.M.A. (Con-
operating temperature gradually while o.i
struction Industry Manufacturers Association)
films are re- established between pistons and
liners. ehafts and bearings. Safety Manuals. illustrate safe and unsafe
operating rules for heavy equipment.
In colder areas, where temperature is often
below 32°F (0°C). the warm-up period for Before mounting the machine walk cr.lm-
plelely around it making sure that there is no
turbo-charged engines is especially im-
one nearby (Figure 2-13).
portant. The chilled external oil lines leading
to the turbo-charger will tend to slow oil flow
until the oil warms up Slow oil flow to turbo- Courtesy of Consiruction Industry
Manufacturers Association (CNA)

-,..-1..

(2-13) CHECK THE AREA

177
 0.

2:14 STARTING, MOVING AND STOPPING EQUIPMENT

Mount the machine carefully. Always use the Know that the area is safe for vehicle
steps and grab rails provided (Figure 2-14). Do operation. If it is necessary to start an engine
not grasp the steering wheel or other controls- within an enclosed area. provide adequate
Don't get on the machine or operate it with ventilation. Remember, exhaust fumes can kill
wet or greasy hands or with muddy shoes (Figure 2-16).
(Figure 2-15). Never try to mount a machine in
motion. If someone else has been operating
the machine, check the seat adjustment.
Stay seated while operating a vehicle. If the
machine has a roll-over structure. you should
use a seat belt (if equipped). Also. make sure
the seat is adiusted correctly.

(2-16)
Courtesy of Construction Industry
Manufacturers Association (CIMA)

vaillir'" Prior to starting the engine, warn others by

sounding the horn (Figure 2-17).

Courtesy of Construction Industry (2-14)

Manufacturers Association (CIMA)

(2-17)
Counesy 01 Construction Incwstry
manuitiolurors Association (CimA)

401 %simile

(2-15)
Courtesy of Construction Incttbstry
Manufacturers Association (CIMA I

17&
 STARTING, MOVING AND STOPPING EQUIPMENT 2:15

During warm-up check all gauges carefully. Test the engine speed control (Figure 2-20).
Don't operate a vehicle if gauges aren't
working (Figure 2-18).

i,

(2-18) (2-20)
Courtesy of Conetr-ction tqductry
Manufacturers Association (CIMA)
Courtesy 01 Construction Industry
Manufacturers Association (CIMA)

Check the controls. the steering. brakes.

working attachment levers. Get the feel of
levers and the response of the attachments Watch out for the other guy. Prior to moving.
(Figure 2-19). warn anyone who is servicing the machine or
standing in its path (Figure 2-21).

1.

(2-21)

Courtesy of Construction Industry

Manufacturers Association t:IMA)
(2.19)

Courtesy of Construction Industry

Menulactutess Association (CIMA)

179
. ..
2:16 START'i'G, MOVING AND STOPPING EQUIPMENT

Check lights. bark-up alarms. emergency

brake. and other like equipment (Figure 2-22).
AIso. test brakes against engine power on
machines with a torque converter, and test
brakes against ground speed on all tractors

(2-25)

Don't obstruct your vision when moving: keep

the attachment low (Figure 2-26).

WRONG

Never operate any piece of equipment from

other than the operator's seat (Figure 2-23).

(2-26)
Besides obstructing the vision, carrying tne
load high also makes the machine top-heavy
(Figure 2-27).

(2-23)

Never allow anyone to ride on the machine,

the attachment or the load. This is an ex-
tremely dangerous practice (Figures 2-24 and
2-25)

(2-24)
- (2-27)
Courtesy of Construction Industry
Manufacturers Association (COM)
1.80
 STARTING, MOVING AND STOPPING EQUIPMENT 2:17

When operating a machine that has limited V it is necessary to move equipment through
vision sound the horn before making any areas where other machines are working. be
moves It is also a bystander's responsibility to courteous Give loaded equipment the right of
an operator to stay clear of a moving machine Way (Figure 2-30).
(Figure 2.28)

(2-30)

Never swing attachments over men working.

Also. never work under a raised attachment
without first blocking it securely (Figure 2.31).
Remember. all that holds up an attachment is
(2.28) oil trapped in a hydraulic cylinder. If you have
to work under it. block it.

Always be aware of the size of the machine

you are moving. Its a good practice to have
one or more signal men when moving in a
tight spot (Figure 2-29) When driving heavy
equipment on a public road make sure
clearance flags. lights and other required
warnings are cn the machine

(2-31)

Courtesy of Construction Industry

Manufacturers Association (CNA)

181
2:18 STARTING, MOVING AND STOPPING EQUIPMENT

When temporarily parking a machine. set the

parking brake and shift the transmission to
neutral. If the tractor is equipped with a trans-
mission lock. engage it. Lower all at-
tachments to the ground. Never leave a
machine unattended with the engine running.
When parking a machine. try to select level
ground. If parking on a slope cannot be
avoided. position the vehicle so that it can't
roll down the slope (Figure 2-32).

(2-32)

When parking a machine. lower all at-

tachments and relieve all hydraulic controls
so that the cylinders are at rest. Set the
parking brake and Shut down the engine
before leaving the cab (Figure 2-33).

Other good parking practices:

Park a reasonable distance from other
vehicles.
Courtesy of Construction Industry
Haul roads are not parking areas (Figure 2- Manufacturers Association (CIMAI
34). If you must park on one. pick the safest
place.
When parking where traffic is heavy. or
when machine is disabled. mark vehicle
with flags in the daytime and flares at
night.

(2-34)
182
 STARTING, MOVING AND STOPPING EQUIPMENT 2:19

SAFETY PRECAUTIONS WITH

ARTICULATED STEERING
Articulated steering means that the vehicle
has fixed axles and a frame that hinges in the
middle to steer the vehicle (Figure 2-35). Skid-
Jers. some graders and wheel loaders are
examples of machines that have articulated
steering
(2-35) ARTICULATED VEHICLE

-"14111111111111r

Courtesy of Teren. General Motors CorOoration

Machines with articulated steering present a there while the machine was turning. he
particular safety problem When the machine would be crushed. Most articulated machines
hinges or articulates to turn. the two frame will have an Area Warning Decal. like the one
sections of the machine come close together below. on each side of the front frame. Be ab-
in the pivot area on the side nearest the direc- solutely sure when the engine is running or
tion of turn There is no clearance for a person when you're moving an articulated machine
in this pivot area If someone happened to be that no one is in the pivot area.

WARNING
NO ROOM FOR A MAN IN THIS AREA
WHEN MACHINE IS TURNED.
DO NOT STAND OR WORK IN THIS
AREA WHEN ENGINE IS RUNNING.
USE SAFETY LINKS WHEN SERVICING
MACHINE.

183
 2:20 STARTING, MOVING AND STOPPING EQUIPMENT

All articulated machines are equipped with a To lock the two frames in a full turn position
safety bar which will lock the two sections of some machines use the bar (Figure 2-38).
the machine in a straight ahead position or in whereas others just insert the pin between the
a lull turn position. Never make any checks or two frames (Figure 2-39).
do any service on an articulated machine
without first installing this safety bar Before
locking a safety bar. shut off the engine,
relieve the hydraulic pressure. and attach a .-: -- r-
00 NOT OPERATE TAG on the steering
wheel. The safety bar is stored alongside the
frame (Figure 2-36). 40
., F ..{ 4. ...,

AA&

....--
(2 -38) FRAME LOCKING BAR IN
ARTICULATED POSITION
Courtesy of Fiat -Albs Construction
Equipment Inc.

(2 -36) FRAME LOCKING BAR IN

STORAGE POSITION
Courtesy of Fiat-Albs Construction
Equipment Inc

To install tne bar in a straight ahead position.

remove it from its st'rage position and attach
it to the front frame with the pin provided
(Figure 2-37). Besides being used when
working on a machine. the straight bar
position IS also used when transporting the
vehicle

-_F o
(2-39) PIN ONLY IN FULL TURN
LOCK POSITION
Courtesy of internalsonal Harvester

COMMON CAUSES OF INJURY IN THE

HEAVY DUTY FIELD
To summarize the information on safely
moving heavy equipment. always respect the
potential danger of big machines. Care and
common sense when moving or working on
(2-37) FRAME LOCKING BAR IN heavy machines will go a long ways in
STRAIGHTAHEAD POSITiom protecting yourself and fellow workers from
injury. Keep in mind the foliowing list A thc
Courtesy of FiatAllts Construction
Equipment Inc

184
 STARTING, MOVING AND STOPPING EQUIPMENT 2:21

most common causes of injury to those 4 Unexpected violent shocks or pars to the
working on or arouad heavy equipment. machines
1 Repairing and servicing equipment in 5 Uncontrolled traffic involving other
dangerous positions vehicles.
2 Sink png other persons or vehicles with the 6 Hazards from limbs of trees or overhead
machine obstructions
3 Unexpected violent tipping of the equip- 7 Leaving earth-moving or other equipment
ment in dangerous positions unattended.

WOW SAFELY
---'021VE
1

SAFE Y
2:22 STARTING, MOVING AND STOPPING EQUIPMENT

MACHINE STORAGE hot climates. the batteries should be

stored where they will be protected from
Prepare g machinery for storage is an im- temperature extremes.
portant maintenance procedure Failure to
take the necc.>sary steps to protect certain 5 Rust Prevention Clean and repaint all
components prior to storage will result it an rust spots. In addition. cover all exposed
expensive overhaul lob and a costly time machine surfaces with a good rust preven-
delay in getting the machine back to work. tive
Eveiy service manual or lubrication and main- 6 Supply Tanks Open the drain cocks at
tenance guide has a section devoted to the bottom of the unit's air tanks Fill fuel
machine storage. The steps may vary from and hydraulic tanks to prevent moisture
one machine to another but the purpose is the condensation within the tanks
same to protect the machine so that there is
minimum cost and time delay when the unit 7. Tires Inflate alt tires to the correct
returns to work An example of storage pressure. During storage. check lire
procedures for a Terex wheel loader are given pressures approximately once every lino
below The procedures are divided into lour weeks.
categories 8. Engine Consult the ENGINE SERVICE
temporary storage MANUAL for complete information on
storing the engine for periutis shorter than
- extended storage under 6 months 30 days.
- extended storage over 6 months
S. Tranarnizzion Fill trenselisSion sumps
- remove/ from extended storage fo the proper level.
TEMPORARY STORAGE
When storing the loader for a period of 30 EXTENDED STORAGE
days Or less. the fallowing precautions must UNDER StX MONTHS
be taken
When storing the loader for periods of longer
1 Inspection and Repair Thoroughly in- than 30 days but under six months. the
spect and test the unit and make any following procedure must be followed
repairs or adjustments which may be
necessary to prepare the unit for service. Do steps 1. 2. 3 5 and 6 from temporary
This will enable you to put the unit back storage, in addition to the following
into use immediately after taking it from 1 Batteries Remove the batteries from
storage the unit and store them in a suitable place
2 Lubrication Lubricate the unit com- wnere thf v can be inspected and charged
pletely according to the instructions given at least every 30 days or placed on a
in the lubrication section of the manual trickle charger
3 Parking Alter thoroughly cleaning the 2. Tires With the mot up on blocks.
entire unit park it on a hard. dry. level sur- deflate the tires to 10 tbs. pressure Clean
face that is free from grease and oil. The off all grease and oil and protect the tires
oil and grease cause tire deterioration from direct sunlight and water with a
Lower attachments to the ground and set suitable cover.
the parking brake Cover the exhaust 3 Engine Consult the ENGINE SERVICE
stack to keep out rain water MANUAL for complete storage data for
4 Batteries - Where moderate tem- periods longer than 30 days
peratures are expected. the batteries may 4 Vents and Breathers Remove all vents
be left in the unit If the unit is not going to and breathers and plug the openings with
be used for about 30 days. the batteries pipe plugs If this is not possible. seal the
will require a booster at the end of the vents and breathers with waterproof tape
storage period In some cases it would be
advisable to place the batteries in the
shop where they can be inspected and
brought up to full charge In very cold or

186
 STARTING, MOVING AND STOPPING EQUIPMENT 2:23

EXTENDED STORAGE 6. Vents and Breathers Remove seals

OVER SIX MONTHS and plugs from all breather openings.
and install breathers and vents.
Same procedures as for extended Storage Un-
der Six Months in addition to the following. 7. Engines Consult the engine service
manual for instructions on removing an
Wheel Bearing Remove. clean. inspect engine from storage.
and repack all wheel bearings (two
bearings per wheel). 8. Paint Check unit for rust. Remove all
rusty spots and repair rusted areas.
All procedures for extended storage over six
months must be repeated (at least all the ones 9. Transmission Consult the TRANS-
that can be repeated such as. lubricating and MISSION SERVICE MANUAL for in-
rust proofing) for ev y six month period the structions on removing the transmission
machine is in storage from storage.
Engine storage procedures referred to above
would include
I Properly drain the coolant. or make sure
that the cooling system has an adequate
antifreeze solution
2 Remove the infection nozzles Spray about
one Oinice ni firacip SO lisbncahr19 oil ri
each cylinder. Crank the engine saveral
revolutions Clean the infector seats. in-
stall new gaskets (it used). and re-install
the 'rectors
Also. :he hydraulic system should bci treated
in the following way
Coat the exposed portion of the hydraulic
cylinder rods and rod bearings with
chassis grease If the attachment is taken
off for storage secure the cylinders to the
tractor to avoid damage

REMOVAL FROM EXTENDED STORAGE

GENERAL PROCEDURES
I Lubrication Completely lubricate the
i nit according to instructions.
2 Batt' ries Install batteries being sure
they have a rull r:harge and the wale
level IS J/8" if) 1/z" above plates.
3 Tires infiato tires up to the proper
level
4 Air Tanks Check drain cocks to en-
sure that they are closer'
5 Fuel, Hydraulic and Steering Cylin.".er
Tanks - Drain sumps. fill tanks to
proper level. remove breather covers and
install air breathers Be sure breathers
are cleaned before installation

187
2:24 STARTING, MOVING AND STOPPING EQUIPMENT

QUESTIONS STARTING, MOVING AND 12. True or False? An engine decompressing

STOPPING EQUIPMENT mechanism is intended lo be used as an
engine starting aid but in an emergency
1 One of the best sources of inlormation it can be used to stop the engine.
on the operation of equipment is
13. To play it safe when starting a diesel
engine after an extended storage period
2 What is a pre-start check')
or an overhaul. what precaution should
3 What is the purpose of pre-start checks? be taken?
4 Good safety practice when making pre- 14. List three things that would cause the
stars checks is to sentinel system to automatically shut the
engine down.
tai lower all attachments to the ground
15. Why do diesel engines require cold star-
(b1 apply the parking brake
ting aids?
(c) attach a DO NOT START TAG to the
steering wheel 16. The two common types of starting aids
used with diesel engines are
(d1 remove the ign;tion key and open and
the master switcn (if equipped).
(e) all of the above 17. True or False? Ether can be used with a
pre-heater or glow plugs.
5 It is best to fill the fuel tank at the end of
a shift because 18 To avoid damaging an electric starting
motor. the maximum cranking time when
Cal it is easily forgotten in the morning starting me engine should not exceed:
(1)1 condensation in the tank is reduced (a) 45 seconds
(c) the tank will hold more when it is (b) 30 seconds
warmed up
(c) 60 seconds
(d) sediment will have time to settle out
of the fuel (d) 15 seconds

6 Referring to the walk around inspection 19. When using ether as a cold starting aid.
diagram for the Caterpillar excavator. use it ____ to avoid
what should the track be checked for? damaging internal engine parts.

7 Referring to the pre-start checks for the 20. Why is it a good practice to idle an
Haul-Pack off-highway truck. what type engine three to five minutes before
of brake fluid is used at above 0 F tem- shutting it down?
peratures to top up the brake reservoirs/ 21. If the emergency stop is used on a
8 What is the most important thing to know Detroit diesel. what must be done before
before starting an engine? restarting the engine?

(a) how many speeds the transmission 22 Why are long periods of idling not
has recommended for diesel engines'
OA of all the lights are working properly 23 How should an engine be brought up to
operating temperature?
(c) where the starter switch is located
(dl how to stop the engine 24 Should the electric solonoid fuel shut-off
on a Cummins engine fail. how can the
9 List the three wuys diesel engines can be engine be started or stopped/
stopped
25 The glow plugs discussed for Caterpillar
10 True or False') The main purpose of an engines are located in
engine governor is to prevent the engine
from overspeeding. (a) the intake manifold
(b) the intake ports
11 If vie emergency stop is used regularly
to slop a Detroit diesel engine. what (ci combustion chamber
damage is likely to occur? (d) pre-combustion chamber

188
 STARTING, MOVING AND STOPPING EQUIPMENT 2:25

26. When the pre-start checks are complete.

what should you do prior to mounting the
machine to start and move it?
27 What is the recommended practice when
moving a large piece of equipment in
tight surroundings?
28. List the basic steps to be taken to park a
machine safely.

29. The steering safety bar used on ar-

ticulated machines is used for two pur-
poses. One is for safety when working on
the machine. What is the other?
30. Why are specific steps taken to prepare
a machine for short or extended storage.
rather than just parking it?
31. Referring to the storage procedures for
the Terex loader. what should be done to
the vents and breathers when storing thd
machine for four months?

189
2:26 STARTING, MOVING AND STOPPING EQUIPMENT

ANSWERS - STARTING, MOVING AND 22. When idling for long periods of time the
STOPPING EQUIPMENT temperature of the combustion chamber
drops so tow that fuel does not burn com-
1. ... manufacturer's operating rianuals. pletely causing carbon build-up.
2 A pre-start chec:. is a systematic series clogging of injector spray holes.
of checks on engine driven equipment clogging of rings and even sticking of
prior to starting, the valves.

3. To ensure that the machine is in good, 23. By gradually increasing the idling speed.
safe running condition before beginning
its shift. 24. By pushing the manual override button
on the solonoid.
4. (e) all of the above
25. (d) pre-combustion chamber.
5. (b) condensation in the tank is :educed
26. Walk completely around the machine to
6. Broken or missing shoes and bolts. ensure that all persons are clear.
7. SAE J1703 27. Use one or more signal men to guide the
operator.
8. (d) how to stop the engine
28. - park on the flattest ground possible
9. 1. shut off the fuel
- lower all attachments
2. cut off the air
- set parking brakes
3. de-compress the cylinders
- shut engine down and neutralize all
10. True. hydraulic controls
11. Using the emergency stop on a regular 29. To keep the frames parallel when ship-
basis will damage the scavenge blower ping the machine.
seals.
30. To protect the machine so that there is
12. True. minimum cost and time delay when it
returns to work.
13. Remove the air intake and have a piece
of smooth plywood ready to cover the 31. Remove all vents and breathers and plug
inlet. the openings with pipe plugs. If this is
not possible. seal the vents and
14. 1 The engine overheating breathers with waterproof tape.
2. Low oil pressure
3. The engine over-speeding
15. 1. Ignition of the fuel is accomplished
by heat of compression. Cold air
when compressed may not reach a
high enough temperature to ignite
the fuel.
2. Diesel fuel is less volatile in cold
weather.
16. ether and pre-heaters or glow
plugs.
17 False
18 (b) 30 seconds
19 . sparingly .

20 To allow the engine to cool off gradually.

2t Go to the engine and manually reset the
latch handle.

120
 STARTING, MOVING AND STOPPING EQUIPMENT 2:27

TASKS (b) normal shut down mechanism

STARTING, MOVING AND (c) emergency shut down mechanism
STOPPING EQUIPMENT 2 Start the engine. Check all gauge
readings and warning devices.
PRESTART CHECKS
3 When the gauges read normal. before
On each of the following heavy equipment moving the machine. release the parking
units that is available to you. carry out the pre- brake. check the operation of the brakes.
start and walk around checks listed below: and give a signal for forward or reverse
truck and tractor truck direction.
off-highway truck 4. Move the machine in both a forward and
crawler tractor (current) reverse direction and activate all working
attachments.
front end loader (articulated)
grader
5. Park the machine. lower all working at-
tachments. apply the parking brakes and
shovel. log loader or crane do a normal shut down.
back hoe excavator 6. Consulting the service manual. prepare
one of the above machines for an ex-
PRE-START AND WALK AROUND tended shut down.
CHECKLIST
7 On a machine with articulated steering in-
Make any minor repairs. Do not start the stall and remove a steering safety rod.
machine if major repairs are needed.
1. Consulting the vehicle's service manual.
locate all fluid check points. Check the
fluid levels and top up any that are low
with the recommended fluid.
2 Check the complete machine for oil leaks.
and for fuel and coolant leaks.
3 Look to see if there is a "Do Not Operate"
Tag(s) on the controls.
4. Check the machine over for missing or
loose components
5. On wheel machines visually check tire
condition and pressure.
6. On track machines check for missing or
loose track shoes and track components.
Also check the track tension.
7. Set parking brakes.
8 Put controls in neutral.

START, MOVE AND SHUT

DOWN VEHICLES
On each of the above heavy equipment units
that is available to you. carry out the start.
move and shut down procedures listed below.
1 Before starting locate and check (if equip-
ped) t"e operation of:
(a) cold starting aid

191
 BLOCK

3
Principles and Theory
of Hydraulics

192
 PRINCIPLES AND THEORY OF HYDRAULICS 3:1

Hydraulics is the science of transmitting

force and motion by a confined fluid. The
material in this block is intended as a basic
CROWD
introduction to hydraulics. At a later stage in CYLINDER
training the subject will be dealt with in
greater detail.
A trend in modern machinery has been to BOON
CYLINDER BAC(HOE
replace manually operated components with CONTROL
hydraulically operated ones, Virtually every LEVERS

modern heavy duty machine uses one or more

hydraulic systems.
BACKHOE
CONTROL
Below are some of the common applications VALVES
of hydraulics.
Brakes Many machines use
hydraulic brakes in one
form or another.
Steering Just about all steering
today is hydraulically
powered. In fact without
LEFT-HAND
hydraulics it would be im- STABILIZER CYLINDER
possible to steer some of
the larger machines. Sworn
Y tto/ CYLINDER
Transmissions All power shift trans-
missions use hydraulics to
obtain speed and ratio
(3-1), Backhoe Operating Pans
changes.
Working and Buckets. blades. rippers. FORK n *a
Attachments hoist& winches, are all $1 la
f
hydraulically operated.
.
Propel Hydraulic propel has been i

used on many small lti

machines such as It? f9
agriculture tractors, and is
tt
be
now becoming very i
popular on larger equip- (3-1)
ment such as excavators, Forklift Operating
John Deere makes one of Positions
its dozers with hydraulic
propel and steering com-
bined.
X 1 let
Winches Hydraulically driven win-
ches are becoming more 4-;?;:k1
popular. both for tractor-
mounted and hoist win.
ches.
(3-1)
Loader Operating
o ie
/
,;P;;11
e

Positions CONTROL (4ee,i4ve

Examples of hydraulically operated working LEVER k(4,3; =PING
attachments are shown In Figure 3-1. CONTROL
,,e09 BUCKET
VALVES
BUCKET
CYLINDER

// / BOON CYLINDER BOOM --"t4

Courtesy of John Deere Lid

193
3:2 PRINCIPLES AND THEORY OF HYDRAULICS

The reasons for the popularity of hydraulic 1. Liquids have no shape of their own; a
systems can be seen by looking at their ad- liquid takes the shape of its container
vantages: (Figure 3-2).
1. Hydraulic systems are simple in con-
struction. A few basic hydraulic com-
ponents will replace complicated
mechanical linkages. With less moving

2.

3.
parts. there are fewer points of wear.
Since hydraulic systems are controlled by
relief of safety valves, vital parts of the
system are protected from damage.
Hydraulically operated parts move very
smoothly.
X 1071
se
(3-2) Liquids Have No Shape of Their Own.
4. Hydraulic systems give a wide range of
Courtesy of John Deere Ltd
speed and force.
5. Hydraulic force is multi-directional; it can
push, pull or rotate. Having the property of shapelessness, oil
in a hydraulic system will flow in any
Of course. no system is without some disad- direction and into a passage of any size or
vantages: shape.
1. Hydraulic systems are subject to leaking. 2. Liquids will not compress. For example, if
When a hydraulic system is working. it is the cork of a tightly sealed jar was pushed
submitted to high pressures. shock down, the liquid in the jar would not com-
loading and heat, and leaks can occur. press. The jar would shatter first. For ob-
2. Heat from friction in a hydraulic system vious safety reasons. Ws not recom-
causes some loss of efficiency. mended you try this experiment (Figure 3-
3).
3. Hydraulic systems have to be kept clean.
They must be protected against rust,
corrosion. dirt. and oil contamination. any
of which can ruin their precision parts.

BASIC PRINCIPLES OF HYORAULICS

A hydraulic system in a machine operates ac-
cording to a few, simple principles;
Liquids have no shape of their own.
deb

Liquids will not compress,

Liquids transmit applied pressure in all 110

directions. X 1072 4 4
Liquids provide great increases in work (3-3) Liquids Will Not Compress
force. Courtesy of John Deere Ltd
Liquid displaced is equal to liquid gained.
NOTE: to be totally accurate it should be
pointed out that liquids will com-
press slightly under pressure (1/2
to 1% at 1000 lbs. per sq. in.). In
the present discussion. however,
fluids will be considered in-
compressible.

194
 PRINCIPLES AND THEORY OF HYDRAULICS 3:3

3. Liquids transmit applied pressure in all The first cylinder has a surface area of
directions. The experiment in (2) shattered one square inch and the second has a sur-
the glass jar and also showed how liquids face area of ten square inches- A force of
transmit pressure in all directions when 1 pound is put on the piston in the smaller
they are put under compression. Here is cylinder. Once again the one pound per
another experiment: square inch pressure is spread throughout
the oil. Since the larger cylinder haS, 10
Take two cylinders of the same size (one square inches at its surface. each one of
square inch) and connect them by a tube those 10 square inches exerts a force of 1
(Figure 3-4). Fill the cylinders with oil to pound. Together they exert a force of 10
the level shown Place in each cylinder a pounds. the force needed to balance a 10
piston which rests on the columns of oil. pound weight. In this way the fluid has
Now press down on one cylinder with a greatly increased the work force: an input
force of one pound. This pressure is force of 1 pound has given an Output force
created throughout the system, and an of 10 pounds.
equal force of one pound is applied to the
other piston. balancing the 1 ib. weight A work force increase made hyOraulically.
put on the second cylinder. as in the above example. is similar to a
work force increase that can be achieved
by mechanical leverage. In the following
diagram the 1 pound force acting at 10"
from the fulcrum will balanCe a 10 pound
force acting at 1 inch from the fulcrum.

- (3.4)

Courtesy of John Deere Ltd

This experiment shows that when

pressure is applied to one area of a con-
fined liquid. the liquid will spread th.at
pressure to all its other areas. When 1
pound of pressure is applied to the area of 5. In a confined system of joining cylinders
oil in the left hand cylinder. the oil spreads the amount of fluid displaced from one
the 1 pound pressure to the part of itself in cylinder is equal to the amount of fluid
the other cylinder, making the pressure gained by the other cylinder. For example:
the same throughout the liquid. (a) When the cylinders (i.e.. the pistons)
4. Liquids provide great increases lc work are of equal size. movement of one
force. Take two l.ylinders of different sizes piston will cause an equal movement
end connect them, as shown in Figure 3-5. in the other piston (Figure 3-7).
I_ if.
i--1---1
q=11.
ti.1

T
1.,

.1=10 .1=10 /ROO OPM 4MP INN 1

1"

Courtesy of John Deere Ltd

(3-7)

195
 3:4 PRINCIPLES AND THEORY OF HYDRAULICS
1

(b) When the cylinders are of unequal PRESSURE, FORCE AND AREA
size. the smaller piston will move far-
ther than the larger one. In the exam- The words pressure. force and area were used
ple below the 1" diameter piston above when describin3 the experiments that
moves 10 inches while the 10" demonstrated the basic principles of
diameter piston moves 1 inch. The hydraulics. Given here is 4 definition of these
fluid lost from the first cylinder, hydraulic words and a formula that shows the
though. is equal to the fluid gained relationship between the two.

141- '''41
14-- 10"-01
by the second (Figure 3-8). Force

Area
a push or a pull measured in
units of weight (lbs.).
the surface space on which a
I force is applied. Measured in sq.
ins.
1"
Pressure a force applied to a certain area.
I
the force is measured in lbs..
T and the area it is applied to in
square inches. Pressure is
measured in pounds per square
10" inch (F.S.I.); r.e., if 30 lbs. of
pressure were applied to 10
square inches, the pressure
would be 30 ÷ 10 = 3 lbs. per
square inch.
The following relationships exist between
pressure force and area.
Pressure = Force ; P=F
i
.i,rea A
(3.8)
Force = Pressure x Area; F = PxA
Note the factor of piston speed here.
Since the fluid is displaced by one cylin- Area = Force ; A=F
der and gained by the other at the same Pressure P
time, the smaller piston travels 10" in the
same time it takes the larger piston to An easy way to remember these formulas is by
travel 1". The smaller piston therefore using the following triangle.
travels much faster (10 times fastee).
In points 4 and 5 above. fluid was confined be-
tween two interconnecting cylinders. In point
4 force was transmitted by the fluid; in point 5
motion was transmitted. Now combine the two
points and you have force and motion applied
to one cylinder (:vaster cylinder) transmitting To understand how it works, look at the
a force and motion to the other cylinder triangle as you read the formulas:
(working cylinder). The amount of force and
motion transmitted to the working cylinder F = PxA P =F A=F
depends on the relative sizes of the two cylin- K -1:7

ders. Such an arrangement is a basic con-

fined hydraulic system es would be found in
hydraulic brakes. The brake master cylinder To do basic hydraulic problems involving P,
sends force and motion by fluid to operate the F. and A, you have to know how to square a
brake wheel cylinders. number and how to use the formula for the
area of a circle.
Note that a confined hydraulic system is being
discussed here. A circulating hydraulic
system using a pump and reservoir will be
discussed later.

196
 PRINCIPLES AND THEORY OF HYDRAULICS 3:5

t. To square a number multiply the number Solution

by itself.
Knowing that F = P x A. you must find the
examples: pressure (P) and the area (A) of the large
(a) 22 (read two squared) = 2.<2=4 cylinder before you can find the force (F).
(b) 32 = 3x3=9 Step 1 First of all the area of each piston
(c) 14 = 14x14=196 should be found. Since the
diameters are given. use the Area
form:* with the diameter in it.
2. Area of a circle = wr2 where w is equal to
22 or 3.14. and r is the radius of the circle. (a) A = .79D2
7 A= .79 x 1 x 1
The formula can be written:
A = .79 sq. in. is Area of small
Area of a circle = 22 xrxr cylinder top.
7
(b) A = .79 02
If the diameter (0) ratner than the radius A = .79 ,. 3 x3
of the circle is given this formula can be
useo:
A = .79 x9
A = 7.11 sq. in. is Area of large
Area of a circle = .79 x D' cylinder top.
Example Area problem: What is the area of a Step 2 Now find the Pressure of the small
circle of 2" diameter?
A = .79 x 02
cylinder using . since you
A = .79 x 2" x 2"
A= .79 x 4 sq. in. know the F and the A. The pressure
A = 3.16 sq. inches in the large cylinder will be the
same.
EXAMPLE PRESSURE, FORCE, AND p F
AREA PROBLEMS
A
If a 100 lb. force is applied to a 1" diameter
piston. what force %%911 be exerted on a 3" P = 100
diameter piston tFiciure 3.9)? .79
7
f
100 lbs. Force P = 126.5 P.S.I.
That means that the pressure throughout the
system is 126.5 P.S.I.
Step 3 Since you now know the (P) and the
(A) fo, the large cylinder. you can
find the force.
F=PxA
F= 126.5 x 7.1t
1" 3" diameter piston
F = 899.4 lbs.
dia
899.4 pounds will be exerted at the larger
piston cylinder. Thus the work force has increased
from 100 lbs. to 899.4 lbs.

(3.9)

J.97
3:6 PRINCIPLES AND THEORY OF HYDRAULICS

PRINCIPLES OF HYDRAULIC CYLINDERS 3. If tne fluid oressure remains constant xi

the area of the working cylinder
The formula, Pressure Force can be used creases. the outward force on the work in
Area piston increases because there are more
to verify basic principles of hydraulic cylin- square inches of force acting on it (Figure
ders. 3-12).

1. Given the same applied force, as the area

of the cylinder decreases, the pressure in-
creases. In Figure 3-10 the pressure in-
creases because the force is con-
centrated on less area. Instead of the 100 100 lbs. 200 lbs.
lb. pressure being applied to 1 sq. in.. it is
applied to '/2 sq. in.
100 lbs.
100 P.S.I.
P=F
A
= 100
1

= 100 P.S.I.
F=PxA
. WO x 2
P=F = 200 lbs.
A
= 100 (3-12/
5
= 200 PS.I. 100 lbs. 400 lbs.

(3-10)
i 4
sq. in.1 4 sq. ins.
2 Conversely. if the size of the cylinder in- L--I1

creases. the pressure decreases (Figure

3-11).

I100 P.S.I.
100 lbs. 100 lbs.
T 100 P.S.I. lir 50 P.S.I.

2 sq. ins. F -:. P x A

= 100 x 4
-.: 400 lbs.

P=F
(3-11) A
= 100
2

= 50 P.S.I.

198
-211114:4 iiiMMINIXIIMEMIPM1574:3,is__01
 PRINCIPLES AND THEORY OF HYDRAULICS 3:7

HYDRAULIC FLOW the greater the friction. Since line size is

directly related to fluid velocity, it is important
Flow is defined as the movement of a fluid. that lines be of adequate diameter so that the
The discussion so far has considered con- fluid does not travel at too high a speed and
fined hydraulic systems of one cylinder or of cause overheating in the line. For this reason
two interconnecting cylinders where fluid always replace hydraulic lines with the same
flows back and forth between the cylinders. In size as the originals.
a circulating hydraulic system fluid flows from
a reservoir to a pump to a working cylinder FLOW IN CYLINDERS
and back to the reservoir again. Flow is
measured by velocity tnd by fk.w rate.
1. Velocity is the average speed of a fluid
141-- 2 Ft. Ill
past a given point. Velocity is measured ;n
feet pe- second (F.P.S.) or feet per minute
(F.P.M.). Flow velocity must be taken into 1011.
account by a mechanic when sizing
hydraulic lines.
(3-14)
2. Flow rate is the measure of the volume of
fluid that passes a point in a give. t time. It
is usually measured in gallons per minute
(...; P.M.). Load
FLOW IN LINES
Velocity and flow rate are close; related.
Given that a fluid is traveling through a cer-
tain line size. flow rate will di,-snnine :he
v:.locity at which fluiJ will have!. To illustrate In the two cylinders in Figure 3-14 one G.P.M.
this point. pump a fluid at J constant TPA:. of 1 ta pumped into each cylinder. The piston in
G.P.M. through two 1 gallon pipe sect .ins of the smaller diameter cylinder must travel
different diameter. Eac.i section will be err.- twice as far. and therefore twice as fast, as the
tied and refilled every minute ( Figure 3-13). piston in the larger diameter cylinder. The
smaller piston can do this because the
A 13 velocity of the fluid in its cylinder is twice as
fast. This example illustrates that given an
4 1 Ft. 1 14---- _ ._
2 Ft --ri! equal flow rate of fluid into two cylinders the
.,,,...,..... ...10.
piston in the smaller cylinrier travels farther
and faster than the piston in the larger.
..-0.- However. the advantage is not all on the side
....1.41.
1 Gallon of the smaller cylinder. Rememter that the
...._,.. Velocity -- 2 F.P.M. bigger the cylinder area, the bigger ti-,I force
on the cylinder. The piston in the larger cylin-
I
--
Velricity 1 F.P.M.
(3-13)
der will not move as fast or as fat, hut it moves
with a greater force. A counter balance exists:
what you get in speed yo..t give up in force.
Manufacturers have this counter balance in
To have a flew rate of 1 G.P.M. the fluid in mind when choosing the size of a hydraulic
pipe suction A has a vs:Jcity of foot per cylinder. They must balance the load a piston
mlft..lie. To have the SP:Tle flow rate of 1 G.P.M. is expected to lift against the speed and
the fluid in pipe scction B must travel at 2 feet distance it has to move. Looking at the
Per minute. This to get the same flo 4 rate hydraulic cylinders on the back hoe in Figure
through .14terent size pipes, the smaller the 3-1, the boom cylinder, the crowd cylinder and
diameter of the pipe, the faster the velocity of the bucket cylinder are all a different size and
the fluid has to be to move through it. length. Each of the hoe's cylinders is
designed weighing the force with which its
Wfs.,:, fluid travels through a pipe. friction is component acts against the speed and
cre.ated; the greater the velocity of the fluid, distance the component must travel.

t
_

199
3:8 PRINCIPLES AND THEORY OF HYDRAULICS

HYDRAULIC OIL BASIC CIRCULATING HYDRAULIC SYSTEM

The oil in a hydraulic system is the medium The purpose of a hydraulic system is to con-
which transmits power. It is also the system's vert mechanical energy into hydraulic energy
lubricant and coolant. Although the manufac- which will perform work. Figures 3-15 shows a
turer's service manual will say what type of oil basic circulating hydraulic system with the
to use in its hydraulic systems. it is worth ccotrol valve in neutral position.
mentioning the factors that go into selecting
an oil that will give good performance and
long life to a hydraulic system. A basic hydraulic system consists of the
following parts:
I. Viscosity Viscosity is the measure of
fluidity. in addition to dynamic lubricating 1. A reservoir stores the oil.
properties. oil must have sufficient body to 2. The Pump supplies the push or force
provide adequate sealing effect between which causes fluid to flow and thus to
working parts of pumps. valves, cylinders back up and create pressure. The pump is
and motors. but not enough body to cause driven by the engine and is designed to
pump cavitation or sluggish valve action. supply a maximum amount of gallons per
minute.
2. Viscosity Index Viscosity index reflects
the way viscosity changes with tem- 3. Relief Valve keeps the system from
perature. The smaller the viscosity change overpressurizing. A hydraulic system is
the higher the viscosity index:. The designed to operate at a certain pressure.
viscosity index of hydraulic oil should not The relief valve is set at this pressure.
be less than 90. When the setting is exceeded. the valve
opens releasing pressure and safeguar-
3. Additives Research has developed a ding the system from damage.
number of additive agents which improve
various characteristics of oil for hydraulic 4. Control Valve directs a flow of
systems. These additives are selected to pressurized oil from the pump to the cylin-
reduce wear, increase chemical stability, der. It also directs the oil coming from the
inhibit corrosion and depress the pour cylinder back to the reservoir.
point. The most desirable oils for
hydraulic service contain higher amounts 5. Cylinder converts the hydraulic flow
and pressure to mechanical work energy.
of antiwear compounding.
The following are examples of three types of
oil that have the viscosity, viscosity index and
additives necessary to meet SAE and API ser-
vice ratings for n hydraulic system.
I. Series 3 Diesel Engine Oil
2. Automatic Transmission Fluid Types. A, F,
and Dexron Courtesy of John Deere Lid
(3-15)
3. Hydraulic Transmission Fluid C-1 and C-2.

. ... ............................

RELIEF
VALVE

PUMP
CONTROL
VALVE

CYLINDER

200
 PRINCIPLES AND THEORY OF HYDRAULICS 39

At*:: ........ ........

tTHIS OIL
\t
RETURNS
TO RESERVOIR

O
PRESSURE /ar
OIL RAISES
VALV! IS PISTON AND
SHIFTED. LOAD
DIRECTING
OIL AS SHOWN

(3-16)
Courtesy of John Qeere Lid.

Figure 3-16 shows the hydraulic system in

operation.

The control valve is in the raised position. Oil GRAVITY

from the pump flows through the control valve RETURN

to the bottom of the cylinder where it exerts a

force and drives up the cylinder. Oil from the
top of the cylinder flows through the control
valve and back to the reservoir. There are two
ways that the piston can return to its original
position. One way is by gravity; if pressure is
released from the bottom of the piston the
piston will gravity drop and in so doing will
push the oil out the bottom of the piston
through the control valve and back to the
reservoir. A cylinder that operates like this is
called single acting (Figure 3-17). The other Raise Louts
way of returning the piston is by supplying SINGLE - ACTINGI
pressurized oil to the top of the piston and
driving it back to the bottom of the cylinder.
(3-17)
Pressure is first released from the bottom of
the piston and the return driven piston forces
the oil out through the control valve to the in*
reservoir. This cylinder is called double acting
(Figure 3-17).

Extend

Rkago

I DOUBLE - ACTING

Courtesy 0 John Clem Ltd.

201
3:10 PRINCIPLES AND THEORY OF HYDRAULICS

HYDRAULIC COMPONENTS FILLER

RETURN
ETURN
Reservoirs while reservoirs are the shn- AIR \ f LINE
plest of the components of a hydraulic system. VENT 11 *OUTLET
they are vital to its proper operations. I TO PUMP

Every hydraulic system must have a reservoir.

The reservoir not only stores the oil. it also
helps keep the oil clean. free of air. and
relatively cool.

CAPACITY OF RESERVOIRS
A reservoir should be compact. yet large OIL
enough to: LEVEL
GA('GE BAFFLE INTAKE DRAIN
1. Hold all the oil that can drain back into FILTER
the reservoir by gravity flow. :::. (3-18) Reservoir SCREEN
2. Maintain the oil level above the suction Courtesy of John Deere Ltd.
line opening.
3. Dissipate excess heat during normal 4. Outlet and Return Lines are designed
operation. (See also "Oil Coolers". which to enter the reservoir at points where air
follows.) and turbulence are least. They can enter
4. Allow air and foreign matter to separate the reservoir at the top or sides, but their
from the oil. ends should be near the bottom of the
tank. If the return is above the oil level. the
return oil can foam and draw in air.
FEATURES OF RESERVOIRS NOTE: Be careful when placing extra
To serve its purpose. the reservoir (Figure 3- returns from auxiliary equipment
18) must have several features. in the reservoir. if not placed
correctly, they can cause foaming
1. Filler Cap should be air tight when of return oil.
closed. but may contain an air vent which
5. Intake Filter is usually a screen used in
filters air entering the reservoir to provide
a gravity push for proper oil flow. The air series with the system oil filter which may
vent filter must be kept clean to prevent also be installed in the reservoir.
partial vacuums which restrict gravity flow 6. Drain Plug allows all oil to be drained
from the reservoir. from the reservoir. Some drain plugs are
NOTE: Ideally, a system may be designed magnetic to help remove metal chips and
with a sealed reservoir and no air burrs from the oil.
vent. However. since most systems The location of the reservoir depends upon
have changing oil levels and tem- the design of the machine. the available
peratures and different piston space and the size of the reservoir (Figure 3-
sizes. air venting is needed. 19).
2. Oil Level Gauge gives the level of oil in
RESERVOIR IN SEPARATE TANK
the reservoir without opening it. Dipsticks
are still widely used, however.
3. Baffle helps to separate return orl from
that entering the pump. This slows the cir-
culation of oil. gives the return oil time to
settle. and prevents constant reuse of the
same oil. However. no baffle is needed in
many modern systems because the same
separation of inlet and return oil is
achieved by placement of lines and filters

(3-19) Courtesy of John Deere Ltd.

202
 PRINCIPLES AND THEORY OF HYDRAULICS 3:11

FILTERS The most common type of filtering system is

called a full flow system which filters the oil
The function of filters in a hydraulic system is each time it circulates through a cycle. The
to catch and retain contaminants that get into number and arrangement of filters will vary
the oil. Since hydraulic oil is a lubricant as from machine to machine. One basic
well as a power transmitter, the oil must be arrangement is to have a filter on the inlet line
free of contaminants so as not to score or and another on the return line to the reservoir.
damage precision parts. Contaminants will The inlet filter will be a course filter called a
inevitably enter into the oil from dust in the air strainer which will not restrict flow to the
(machines often work in very dusty con- pump. The return line will have a finer grade
ditions) and from normal wear which causes filter that will sift out the contaminants before
chips and burrs to break off from the metal they get into the reservoir.
pads. There are many kinds of filters made
having a broad range of filtering capabilities. PUMPS
A filter has to be fine enough to catch con-
taminants, yet still allow the oil to freely cir- The primary purpose of any pump is to create
culate through it. Filters will hold only so flow. Pumps work on a principle called
many bits and particles before they start to displacement; fluid is taken in and then
restrict the flow of oil. and therefore they must displaced (i.e., made to flow) to another point.
be changed regularly. Hydraulic pumps are referred to as positive
Two main types of filters are a cartridge filter displacement pumps. They not only create
that fits into a housing and a spin-on filter flow but support the flow, creating a pressure
threaded onto a housing (Figures 3-20. 3-21).
in the' system. The combination of flow and
pressure is the source of working power in a
hydraulic system.
tt-
; A hydraulic pump creates positive
displacement or pressure in the following
.0, way. The pump is constructed to run with
close tolerances between the moving and the
stationary parts. thereby forming a seal be-
tween the inlet and outlet. When the pump ap-
plies a force to the fluid on the outlet side of
the pump, the fluid can't flow back to the inlet
side because of the seal. The fluid, therefore
must flow from the outlet. As it does it meets a
resistance to flow and in counteracting this
resistance a pressure is built up in the fluid.
FILTER EL":MENT The output of a pump is rated by the number
of gallons per minute that the pump can
deliver at a given RPM and pressure. Most
FILTER COVER
pumps are rated at a higher capacity than is
needed for the job that they must do. A pump
(3-20) Cartridge Filter tt, with reserve capacity will wear slower than
couriesly_ 01 John Deere Ltd one without the reserve, and when it does
begin to wear it has some margain before
falling below the system's requirements. Signs
that a pump is wearing out will be a slowing of
cylinder action because of a reduced flow of
fluid. and a loss of system pressure.
Three basic types of pumps are used in
hydraulic systems: gear. vane. and piston
pumps (Figure 3-22). Each type has charac-
teristics that make it suitable for a certain
system.

(3-21) Spin on Filter

203
3:12 PRINCIPLES AND THEORY OF HYDRAULICS

VANE PISTON
GEAR (3-22) Three Types of Hydraulic Pumps Courtesy of John Deere Ltd

HYDRAULIC MOTORS Motor Is

Poop Delves Driven By
In the discussion of a basic hydraulic system. Its Fluid Its Fluid
a pump supplied hydraulic pressure and flow
to drive a cylinoer. A pump can also be used
to drive a hydraulic motor.
A hydraulic motor works in reverse to a
hydraulic pump". the pump drives its fluid
while the motor is driven by its fluid (Figure 3-
23). A pump draws in fluid and pushes it out.
converting mechanical force into fluid force.
Conversely. a motor has fluid forced into and
out of it, and in the process fluid force is con-
verted into mechanical work force. PUMP MOTOR

(3-23) Hydraulic Pump and Motor Compared

Courtesy of John Deere Ltd.
The basic operation of a hydraulic motor is
explained in Figure 3-24.

4. The shoft is
mechonically linked

S. Fluid is discharged
I,cre of tow pressure
and routed back to the
3. This motion in turn
rotates the attached
shaft. r to the work load and
provides rotary mech.
anical motion.

pump.

Nif.;:....

2. This fluid forces

the motor's movable
elements into motion.

1. High Pressure fluid

from the hydraulic pump
enters the motor here.

(3-24) Basic Operation of Hydraulic Motor

Courtesy of John Deere Ltd.

204
 PRINCIPLES AND THEORY OF HYDRAULICS 3:13

Like hydraulic pumps, there are gear, vane Pressure Control Valves are used to limit or
and piston hydraulic motors. The motors are reduce pressure, unload a pump, or set the
rated by motor horsepower, a combination of pressure at which oil enters a circuit.
force and speed. Horsepower = Force x Pressure control valves include relief valves.
Speed. pressure reducing valves. pressure sequence
valves, and unloading valves.
Directional Control Valves control the
CONTROL VALVES direction of oil flow within a hydraulic system.
They include check valves, spool valves, and
Valves are the controls of the hydraulic rotary valves.
system. They regulate the pressure, direction,
and volume of oil flow in the hydraulic circuit. Volume Control Valves regulate the
volume of oil flow. usually by throttling or
Valves can be divided into three major types: diverting it. They include compensated and
non - compensated flow control valves and flow
1. Pressure Control Valves divider valves.
2. Directional Control Valves Some valves are variations on the three main
3. Volume Control Valves types. For example, many volume control
valves use a built-in pressure control valve.
Figure 3-25 shows the basic operation of the
three types of valves. Valves can be controlled in several ways:
manually, hydraulically. electrically, or
pneumatically (compressed gas). In some
modern systems. the entire sequence of valve
operation for a complex machine can oe
made automatically.
Hydraulic valves may or may not be ad-
justable. depending on their location and pur-
pose.
Generally speaking if the hydraulic systfn is
kept clean. valves will give little trouble.

PRESSURE DIRECTIONAL VOLUME

::,# CONTROL CONTROL CONTROL

(3-25) TheThreeTypesolValves

Courtesy of John Deere Ltd

,..
205
3:14 PRINCIPLES AND THEORY OF HYDRAULICS
HYDRAULICS While most accumulators can do any of these
ACCUMULATORS four functions, their use in a system is usually
limited to one of them.
A hydraulic accanulator is basically a cylin-
der with a piston that is opposed by a spring Accumulators which Store Energy are often
or compressed gas. Fluid from the hydraulic used as "boosters" for systems with fixed
system enters the cylinder and pushes against displacement pumps. The accumulator stores
the piston. The piston in turn pushes against pressure oil during slack periods and feeds it
the spring or the compressed gas. Thus the back into the system during peak periods of
piston. with the compressed spring or the oil usage, The pump recharges the ac-
compressed gas exerting a force against it, cumulator after each peak. Sometimes the ac-
becomes a source of potential engergy. This cumulator is used as a protection against
potential energy could be used. for example, failure of the oil supply, for example, on power
in a brake system to apply the brakes if, for brakes on larger machines. If the system oil
some reason, the hydraulic system pressure supply fails. the accumulator feeds in several
failed. charges of oil for use in emergency braking.
Besides storing energy for the hydraulic
system. accumulators can absorb shocks,
build pressure gradually, and maintain a con-
stant pressure (Figure 3-26).

STORE ENERGY IABSORB SHOCKS

4 4

}BUILD PRESSURE GR_ 'MAINTAIN CONSTANT PRESSURE}

COorlosy of John Note LW

206
 PRINCIPLES AND THEORY OF HYDRAULICS 3:15

Accumulators which Absorb Shocks take in range it must at least keep the oil under
excess oil during peak pressures and let it out 250 F. Beyond 250°F a chemical change
again after the surge is past. This reduces takes place in the oil. causing it to oxidize at a
vibrations and noise in the system. The ac- high rate.
cumulator may also smooth out operation
during pressure delays. as when a variable TYPES OF COOLERS
displacement pump goes into stroke. By
discharging at this moment. the accumulator Air-to-Oil Coolers use moving air to dissipate
takes up the slack. heat from the oil (Figure 3-27). On mobile
machines. the cooling system (radiator) fan
Accumulators which Build Pressure may supply the air blast. The cooler has fins
Gradually are used to soften the working which direct the air over long coils of oil tubes
stroke of a piston against a fixed load. as in a which expose more oil to the air. The cooler
hydraulic press. By absorbing some of the may also have a tank to store a reserve of
rising oil pressure the accumulator slows cooled oil. A bypass valve is also sometimes
down the stroke. used as a safety valve in case the cooler oil
tubes become clogged.
Accumulators which Maintain Constant
Pressure are always weight-loaded which OIL
COOLING
places a fixed force on the oil in a closed cir- OUT
FINS
cuit. If the volume of oil changes from leakage ...-'''' w- _ ' "-
or from heat expansion or contraction. this ac-
cumulator keeps the same gravity pressure on
the system.
.=='----
Pneumatic or Gas Loaded are the most com- 1)
mon types of accumulators used on mobile
hydraulic systems. Gas loaded accumulators OIL --.4"
.,,-----------' I A1R
use the principle that gas will compress while IN AIR-TO-OIL COOLERS FAN
fluid will not. In an accumulator gas and oil (3 -27) Courtesy of John Deere Lid
occupy the same container, but are usually
separated by a diaphram or a piston. The Water-to-Oil Coolers use moving water to
cylinder is charged with an inert gas, dry carry off heat from the oil (Figure 3.28). The
nitrogen (not oxygen), to a specified pre- water flows through many tubes and the oil
charge When the oil opposes the compressed circulates around the cooling tubes as shown.
gas, the gas will compress !tut' providing a On mobile machines, water from the engine
static pressure over the entire system. The radiator is often used for cooling.
compressed gas also acts as a cushion for the
system.
OIL OUT OIL 1N
Pressurized systems can be dangerous.
Always bleed down a system that uses a gas
charged accumulator, before working on it. To WATER
discharge the accumulator. shut down the WATER TUBES
engine and move all the hydraulic controls OUT
through all their operating positions. 41.- WATER
IN
OIL COOLERS
On modern high-pressure hydraulic systems. WATER-T0-01L COOLER
cooling the oil can be a problem. Often nor-
mal circulation of the oil in the system will not (3-28) Courtesy of John Deere Ltd
provide adequate cooling. Thus the need for
oil coolers. Air-to-oil coolers such as the one shown are
usually mounted in front of the engine
The purpose of the oil cooler is to keep the oil radiator, making use of the fan's air blast.
at an ideal operating temperature, 180° to Other coolers can be mounted in a variety of
200°F. If under extreme conditions the cooler locations, but are usually placed near the
cannot keep the oil temperature within this reservoir or the engine cooling fan.

207
3:16 PRINCIPLES AND THEORY OF HYDRAULICS

HYDRAULIC CYLINDERS
A double acting hydraulic cylinder is shown in
Figure 3-29. Cylinders will vary in their
diameter and stroke length.

BLEED VALVE

PISTON
ROD STOP
BLEED (ADJUSTABLE)
HOLES
OIL Stop Valve Arm
OUTLET STOP VALVE

(3-29) PISTONTYPE CYLINDER

Courtesy ot John Deere Ltd.

Some cylinders have a safeguard built into

them to prevent the piston from bottoming out
with a damaging force. As the piston nears
either end of its stroke, passages in the cylin-
der allow the oil to bypass the piston. thus
taking away the pressure that would force the
piston into the ends of the cylinder.
Packing glands are used to seal the cylinder
at the point where the rod extends from the
cylinder. Some of these packings can be ad-
justed to prevent oil leaking from the cylinder.
Adjusting and replacing rod packings and
seals are covered in the discussion of
bearings and seals in Frames, Suspensions
Running Gear and Attachments.
 PRINCIPLES AND THEORY OF HYDRAULICS 3:17

QUESTIONS HYDRAULIC THEORY (b) Indirect displacement pumps.

1. Give at least live uses of hydraulics on (c) Positive pressure pumps.
Heavy Duty Equipment.
(d) Positive displacement pumps.
2. Give at least two advantages and disad-
vantages of a hydraulic system. 10. Hydraulic pump output is rated in terms
of:
3. One of the basic principles which makes
hydraulic action almost instantaneous is (a) Pressure and speed.
that liquid is: (b) Gallonage at a specific R.P.M. and
(a) Compressible: transmits power by pressure.
compressing. (c) Horsepower.
(b) Non-compressible; transmits ap- (d) Gallonage.
plied pressure in all directions
throughout the liquid. 11. What is the effect on the velocity of the
(c) Full of fluid. flow of oil if the line size is decreased?
(d) Frictionless and flows quickly. 12. If a smaller line size was mistakenly put
on a hydraulic system that operated a
4 The pressure (PSI) in a hydraulic hydraulic implement, what would the ef-
system is determined by: fect be on the implement?
(a) Multiplying the force x area =FxA 13. Basically, what is the difference between
a hydraulic pump and a hydraulic motor?
(b) Dividing the area by the force =11
F 14. Name the three basic types of valve!
found in a hydraulic system.
(c) Dividing the force by the pressure
15. An accumulator may be used in a system
__
_ F
to:
(a) Store energy.
id) Dividing the force by the area =F
A (b) Absorb energy.

5. Briefly explain the terms velocity and (c) Maintain a constant pressure.
flow rate. (d) All of the above.
6. The teem viscosity is the measure of 16. The purpose of an oil cooler in a
in hydraulic oils. hydraulic system is to:
Viscosity Index reflects the way viscosity
changes with (a) Keep the oil as cold as possible.
With respect to additives the most (b) tool the oil and ict as additional
desirable oils for hydraulic service con- reservoir.
tain high amounts of Keep the oil at an ideal operating
(c)
temperature.
7. What are the five basic parts required to
(d) Filter and cool the oil.
makeup a hydraulic system?
17. There are two basic types of cylinders
8. The function of filters in a hydraulic used in a hydraulic system:
system is to catch and hold
that get into the acting and
oil. acting.

Pumps used in hydraulic systems are Briefly explain the difference.

9.
referred to as: 18. If you increase the size of the piston in a
basic hydraulic system, what is the effect
(a) Direct displacement pump.
on the output force of the piston? On the
speed of the piston?

209
3:18 PRINCIPLES AND THEORY OF HYDRAULICS

19. What advantage does a small hydraulic

cylinder have over a larger one?
20. What is the effect on a hydraulic system
when the pump becomes worn?
(a) pump heats up.
(b) gallons per minute output is
decreased.
(c) the hydraulically operated working
implement will slow down.
(d) both (b) and (c)
21. What is the function of an accumulator in
a hydraulic brake system?

210
 PRINCIPLES AND THEORY OF HYDRAULICS 3:19

DAILY-ROUTINE AND SCHEDULED (c) Hydraulic cylinder: The weight of an

MAINTENANCE. ON HYDRAULIC SYSTEMS implement pushing against oil trap-
ped in the cylinder(s) creates a
A daily-routine check on a hydraulic system is pressure within the oil.
done as part of the walk around inspection of
the machine and should include: To release the pressure:
1. A careful inspection of the components (a) With the engine off, move all of the
and hoses for leaks and signs of damage. hydraulic controls through all of their
operating positions.
2. A Reservoir oil level check: some
machines use a "dipstick" and some a (b) Loosen the reservoir cap a few turns
sight glass. The machine must be Level for or open the vent screw. Never open
this check. the filler cap of a pressurized reser-
voir without first releasing the
Repair any leaking or damaged hoses and fit-
pressure in the reservoir.
tings right away. Minor repairs, if not attended
to can turn into major repairs and costly down
SAFETY PRACTICES FOR A
time.
SCHEDULED MAINTENANCE CHECK
Scheduled maintenance procedures will be All of the above, plus:
outlined in the service manual. These
procedures will include: 1. Install a steering safety lock on ar-
ticulated machines.
Changing filters
Cleaning screens 2. If the machine has a power shift trans-
mission, apply the shift safety lock.
Cleaning breathers
Adding or changing oil 3. If the machine has a master switch, turn it
off and remove the key.
Replacing damaged hoses and fittings
4. Hang a Do-Not-Operate tag on the con-
Checking hydraulic rams for scores or
burrs trols (Figure 3-30).
S. If implements have to be serviced on the
Scheduled maintenance on a hydraulic raised position, use only the approved
system may also include flushing the system.
Flushing is described near the end of this sec-
blocking to support it.
tion.
When servicing hydraulic systems, practice
the following habits of safety, cleanliness and
good workmanship.

SAFETY PRACTICES ON A
HYDRAULIC SYSTEM
1. Shut down the engine.
2. Unless stated otherwise in the service
manual. lower all implements to the

3.
ground, and level them if necessary.
Apply the parking brake and chalk the
DO NOT
wheels on wheeled /elides.
4. Bleed off pressure in the system so that
you don't get showered with hot oil.
Pressure in a hydraulic system comes
OPERATE
from three sources:
(a) Resistance to pump flow.
(b) Accumulators. (3-30)
CourtosY of Ji Case

2.11
3:20 PRINCIPLES AND THEORY OF HYDRAULICS

It is ab;.r)lutely essential that hydraulic 5. Wrong hose selection Wrong size or

systems be kept clew Practice the follow.ng wrong pressure rating can cause failure.
hat-As of cleanliness when working on or Refer to the hose selection in Block 1.
around hydraulic systems.
1. Clean around filler caps before removing
Ihem.

2. Wash off filter housings. hose fittings and

lines, before removing them.
3. Use only clean containers. funnels. cans.
etc. to transfer oil.
4. Always install cap plugs on disconnected
lines and fittings.
5. Observe good storage practices for
hydraulic oil.
6. When changing a hydraulic pump. clean
the complete area around the pump
before disconnecting it.
Good work practices to follow when removing
and installing hydraulic hoses.
Many hose failures can be related to improper
installation such as:
1. Improper hose length When a hose is
under pressure it expands. Hoses which
are too short have no room for expansion.
and therefore will pull apart. Hoses which
are too long can be exposed to hazards
from moving parts.
2. Rubbing Rubbing will chafe the outer
cover and soon weaken the hose to a
point of failure. Secure the hose by dam-
ping to avoid it coming into contact with
moving parts.
3. Heat Route all hoses away from
exhaust pipes and cooling system pipes
because heat will rapidly deteriorate
hoses.
4. Twisting Hoses should lie naturally.
without any twist. You can tell if a hose is
twisted by looking at the laylines on the
hose. Twisting can occur when a hose is
connected to two moving parts which
have relative movement between one
another. To deter such twisting. split the
movement in the hose by supporting the
hose at its mid point. Use a proper fitting
clamp: don't use one that is too large.
Twisting can also occur if a hose is in-
stalled without using two wrenches to
tighten the fittings. one wrench to hold the
hose. and one to tighten the swivel con-
nector.

212
 PRINCIPLES AND THEORY OF HYDRAULICS 3:21

!WA-- WRONG

'11------(A MKT

I. AVOID TAUT HOSE'

D. AVOID LOOPS

WRONG

D. AVOID TwISTINO

14. AVOID RUBBING'

V. AVOID SHARP BENDS

J. AVOID HEAT'
(3-311 INSTALLING HOSES Courtesy of John Deere Ltd

When removing hydraulic hoses:

1 Probably the most important point when 3. As was said for installation. should the
removing a hydraulic hose is to know swivel fitting be tight. use two wrenches to
what you are disconnecting so that you loosen or tighten fittings to avoid twisting
know what pressure or oil flow to expect the hose.
wnen it's taken off. For example. removing
an intake line from a pump on a system FLUSHING PROCEDURES
with a rer,etvoir mounted high with no shut
off coule result in a pretty big puddle of oil Occasionally a hydraulic system may have to
on the floor. be flushed to remove build up of con-
taminants. Flushing procedures will be found
2. If a number of hoses are being discon- in the service manual; a typical example is
nected in the same area. tag the hoses so shown on the following page.
you know which is which when recon-
necting them.

213
3:22 PRINCIPLES AND THEORY OF HYDRAULICS

GENERAL FLUSHING CHANGE FILTER ELEMENT

METHOD 1 4 CHANGE ALL ELEMENTS IN
THE SYSTEM. INSTALL 10
CYCLE THE MACHINE MICRON ELEMENTS DURING
FLUSHING. f---.,
FOR 15 MINUTES TO STIR UP
1 ANY DIRT PARTICLES IN THE
HYDRAULIC SYSTEM.

REFILL TANK
5 WITH RECOMMENDED
GRADE OF SERIES 3 OIL.
DRAIN THE TANK
RAISE THE BUCKET. EXTEND
2 ALL CYLINDER RODS, DRAIN
THE HYDRAULIC OIL. THEN
ALLOW BUCKET TO LOWER
BY GRAVITY FOR MAXIMUM
DRAIN.

(3.32)
6 FLUSH SYSTEM
SLOWLY CYCLE
CYLINDER OR PAIR OF
EACH

CYLINDERS FOR 10 MINUTES

EACH WITH ENGINE AT HIGH.
IDLE. -....
....7,....

CLEAN TANK
3 REMOVE BOTTOM OR SIDE
IF POSSIBLE AND CLEAN
THOROUGHLY.

7 REPLACE FILTER ELEMENT

CHANGE ALL ELEMENTS IN
THE SYSTEM. INSTALL
ELEMENTS WITH PROPER
FILTERING MEOIA.

If a hydraulic system is very badly con-

taminated, as would occur when a pump
failed and caused a large accumulation of
metal particles in the oil, flushing would not
adequately clean the system. In this case all
the components would have to be completely Courtesy of Caterpillar Tractor Co
disassembled and cleaned. The job would be
a major one and would require the help of a
journeyman.

214
 PRINCIPLES AND THEORY OF HYDRAULICS 3:23

QUESTIONS MAINTENANCE OF
HYDRAULIC SYSTEMS
1. List the things that would be done to a
hydraulic system during scheduleo main-
tenance.
2. Before doing a daily maintenance check
on a machine's hydraulic system. what
safety practices must be carried out?
3. Premature hose failure can occur after in-
stallation because of:
(a) Improper length and twisted.
(b) Being too close to moving parts.
(c) Too near a heat source.
(d) All of the above.
4. What is the most important thing to know
when disconnecting a hydraulic hose? Ex-
plain why.

215
3:24 PRINCIPLES AND THEORY OF HYDRAULICS

ANSWERS - HYDRAULIC THEORY 11. If the line size is decreased. the velocity
of the fluid will increase. When fluid
1, 1. brakes travels at higher speed. greater friction
2. steering and thus heat is created in the lines.
3. working attachments 12. With the smaller lines. the velocity of the
4. transmissions fluid will increase. but it won't increase
5. propel
enough to maintain the flow rate. With
less flow. the implement will operate
2. Advantages. more slowly.
1. Simple in construction 13. A pump drives the fluid while a motor is
2. Gives a wide range of speed and driven by the fluid.
force. 14. pressure control valve
3. System is protected against damage volume control valve
by relief valves.
directional control valve
Disadvantages:
15. (d) All of the above.
1. Subject to leaks from high pressure,
shock loading and heat.
16, (c) Keep the oil at an ideal operating
temperature.
2. Heat from friction causes some lc 4s
of efficiency. 17. ... single ... double
3. Need for cleanliness, must be kept The single acting cylinder can be
clean. powered only in one direction (in ex-
tension), whereas the double acting
3. (b) Non-compressible: transmits ap- cylinder can be powered in two direc-
plied pressure in all directions tions (extension and retraction).
throughout the liquid.
18. The output force will be greater because
4. (d) Dividing the force by the area _F there will be a greater area for the
A pressure to act against. The speed of the
piston. however, will be decreased.
5. 1. Velocity is the average speed of a
fluid past a given point. 19. The smaller cylinder will act with greater
speed.
2. Flow rate is the measure of the
volume of fluid that passes a point in 20. (d) both (b) and (c)
a given time.
21. An accumulator is a safety device in a
6. fluidity hydraulic brake system which supplies
temperature enough fluid to stop the vehicle should
the system fail.
anti-wearing compounding
7. 1. a reservoir
2. a pump
3. a relief valve
4. a control valve
5. a cylinder

8. insoluble contaminants
9. (d) positive displacement pumps
10. (b) gallonage at a specific r.p.m. and
pressure

216
 PRINCIPLES AND THEORY OF HYDRAULICS 3:25

ANSWERS MAINTENANCE OF
HYDRAULIC SYSTEMS
I. changing filters
cleaning screens
cleaning breathers
adding or changing oil
Replacing damaged hoses and fittings
and repairing leaks. Checking hydraulic
rams for scores or burns and leaks.
Sometimes flushing.
2. I. Shut off engine.
2. Lower all implements to the ground
and level them.
3. Apply parking brake or block wheels.
4. Neutralize or bleed off all pressure by
operating all controls and open vent
on reservoir.
3. (di All of the above.
4. Know what you are disconnecting. A head
of oil and/or pressure in the line when
disconnected could prove messy or even
harmful.

217
3:26 PRINCIPLES AND .THEORY OF HYDRAULICS

TASKS HYDRAULICS

PREVENTIVE MAINTENANCE SERVICE SERVICE REPAIR

ON HYDRAULIC SYSTEMS
On a loader. backhoe or similar hydraulically
SAFETY operated machine:
Practice safety when working on hydraulic 1 Completely flush the hydraulic system.
systems by: following flushing procedures outlined in
the service manual.
1. Installing safety bars on raised working
attachments. 2. Remove and clean the screens, install
Bleeding the pressure before
new filters. refill the system with the
2. down
disconnecting lines, removing com- correct type and amount of o:',
ponents or opening the reservoir. 3. Start the engine, activate all controls, and
3. Installing steering safety rod on ar-
check to ensure there are no oil leaks.
Stops the machine and recheck the oil
ticulated machines.
level.
DAILY AND ROUTINE
MAINTENANCE CHECK
1. On a loader backhoe or similar
hydraulically operated machine: inspect
the complete hydraulic system for in-
dications of failure such as leaks at hoses,
at fittings, at cylinder rod seals and pump
seals. for damaged or chafed hoses or
damaged piston rods, and for loose cylin-
der or pivot point pins. Report any suspec-
ted problems to a journeyman.
2. Vent the reservoir. check the oil level and
fill if low.
SCHEDULED MAINTENANCE
On a loader. backhoe or similar hydraulically
operated machine. after consulting the ser-
vice manual:
1. Drain the hydraulic system.
2. Remove and clean screens. install new
filters. and refill the system with the
correct type and amount of oil.
3. Start the machine. activate all controls.
and check to ensure there are no oil
leaks. Stop the machine and recheck the
oil level.

218
 BLOCK

Brakes

I
219
 BRAKES 4:1

BRAKE OPERATION 2. Rubber has a much higher coefficient of

friction than ice and therefore requires a
The function of brakes is to stop or slow a much greater force to be pulled across
vehicle's rate of travel. Brakes operate on a
principle of friction: a fixed. non-turning sur-
face (brake lining) is pressed into contact
with the turning wheels (the. brake drum or
disc) causing a resistance to the wheels' :,

motion which slows and eventually stops the

wheels. In this frictional process. energy of 55 tb.
55 lb.
Ice i!---
motion from the wheels is turned into heat
energy in both the linings and brake drums or
Rubber 1/ 0111111=-1 4 to.

discs. The transfer of motion energy to heat ofilm 33 tb.

energy is in accordance with the Law of Con-
servation of Energy which says that energy CONCRETE
cannot be created or destroyed. only trans-
formed from one tom to another. The linings (4-2)
and drums or discs must quickly absorb and
dissipate the heat, in order that braking action
continue over the lime it takes to stop the Thinking about point 2 you can see that by
vehicle. using different brake lining materials. the
coefficient of friction of the brake can be
BASIC FRICTION THEORY varied. In other words, brake performance can
RELATED TO BRAKES be altered by changing the brake lining
materials. For example. a lining with a high
Friction is the force that resists the movement
coefficient of friction will slow a vehicle with
of one surface over another. The strength of less application pressure than will a lining
frictional force between two surfaces is called with a low C.O.F. Brake linings are often made
the coefficient of friction. Coefficient of fric- of a composition of materials which will suit
tion depends on the types of materials in con-
the braking requirements of a certain vehicle.
tact. the condition of their surfaces, the tem- Some brakes will use both a high friction
peratures of the surfaces, and the contact lining and a low friction lining on two shoes in
speed.
the same brake; this system balances the
In mathematical terms the coefficient of fric- braking effort between the two shoes.
tion is the ratio of the weight of a body to the While discussing brake friction materials. it's
amount of force required to slide it over a sur-
worth noting the other friction materials in
face. For example. if it takes a 60 pound force vehicles. Figures 4-3 and 4-4 illustrate the fric-
to slide a 100 pound block of rubber over a tion materials in a family car and in a shovel.
concrete floor. the coefficient of friction of
rubber over concrete would be: 1. Front disc brakes (pads)
60 = .6 C.O.F. 2. Fan belt
100 3. Clutch facing
4. Rear brake linings
Figures 4-1 and 4-2 illustrate two points about
coefficients of friction.
1. The force needed to pull a material across
a surface is proportional to its weight.

10 lb.
11:1111; 2 lb.
100 lb
mmilligb. 20 lb.
Courtesy of Don
Friction Materials UM
(4.1)

(4-3) THE LOCATION OF FRICTION MATERIALS

IN A CAR.

220
4:2 BRAKES

O Engine Clutch
Hoist Clutch Hoist Brakes
co
(4-4) THE LOCATION OF FRICTION Hoist Clutch Hoist Brakes
MATERIALS IN A SHOVEL
O Crowd Blake
Retract

Crowd Clutch

8 O Swing Clutch
4 7
1 23 5 6 O Tripper Clutch

9 O Swing Brake

10 (1) Travel Brakes

Courtesy of Don Friction Materials Ltd

FACTS ON BRAKING
1. To give an example of the tremendous for- 3. Speed has an even greater effact on
ces involved in braking a commercial braking power than does weight. A
vehicle consider the following: vehicle will need 5 times as much stop-
ping power at 70 km/h, and 9 times as
The average truck having an engine much at 100 km/h as it needs at 35 km/h.
capable of developing 100 horsepower
requires about one minute to accelerate to 4. Other factors affect braking power such
a speed of 60 miles per hour, whereas the as brake shoe leverage. number of tires
same vehicle should be capable of easily and road surface deceleration: these will
stopping from 60 miles per hour in not be discussed in a ,ter course.
more than six seconds. Ignoring the
unknown quantities such as rolling fric- BRAKE CAPACITY
tion and wind resistance which admittedly
play a part in all stops. the brakes must Brakes are classified according to their stop-
develop the same energy in six seconds ping power or horsepower absorption
as the engine develops in 60 seconds. In capacity. Brakes have a limit to the amount of
other words. the brakes do the same horsepower they can absorb without damage
amount of work as the engine in one-tenth to themselves other than normal wear on the
the time. This means that they must brake linings and drums. No control. however.
develop approximately 1,000 horsepower is built into brakes as to how much horse-
during the stop. power they will absorb. If called on to absorb
more horsepower than they are built for.
2. Braking power is directly proportional to brakes will do so and destroy themselves in
vehicle weight. For example a 10,000 the process. It is very important. therefore.
pound vehicle would need twice as much when brakes are designed for a vehicle that
braking power to stop it as would a 5.000 they be of adequate capacity to absorb the
pound vehicle travelling at the same horsepower that a vehicle of a given engine
speed. size. weight and travelling speed will produce.

221
 BRAKES 4:3

TYPES OF BRAKE SYSTEMS Service Brakes slow or slop the vehicle. They
are designed to have a braking capacity suf-
Generally a vehicle or machine will be equip- ficient to stop the vehicle when travelling
ped with two types of brakes: within a speed and load limit. If the speed and
1. parking brakes load limit are exceeded, service brakes will
not perform satisfactorily.
2. service brakes
Figure 4-5 shows a typical automobile or light
Parking Brakes secure a vehicle when stop- truck brake system. Note that this vehicle has
ped. Parking brakes can be used in an disc brakes on the front and drum brakes on
emergency should the service brakes fail, but the rear.
if they are applied when the vehicle is
travelling fast or is heavily loaded, they will
burn out, Parking brakes will be looked at in
greater detail later on in this section.

POWER BRAKE
MASTER CYLINDER
BRAKE PEDAL

z BRAKE HOSE
PARKING BRAKE

"11---- BRAKE LINE

METERING VALVE

BRAKE WARNING
LIGHT SWITCH
\
I
PROPORTIONING VALVE
DRUM BRAKE
DISC BRAKE (REAR)
(FRONT)
(4-5) TYPICAL MODERN BRAKE SYSTEM
Courtesy 01 Elendoi Corporation

222
vf
4:4 BRAKES

SERVICE BRAKES 5. Foundation Brake Assembly

Three types of service brakes are used on (a) drum brakes
heavy duty vehicles: (b) disc brakes
1. Standard Hydraulic brakes
In a standard hydraulic brake system a brake
2. Power-assisted hydraulic brakes pedal is connected to the master cylinder
which acts as the pump for the system.
Vacuum-assisted Pushing down the brake pedal forces a piston
Air-over-oil in the master cylinder against confined fluid
Oil-over-oil creating a pressure in the fluid and causing it
to flow. The pressurized fluid flows to the
3. Full Air-Brakes hydraulic wheel cylinders mounted at each
wheel between the two brake shoes, and the
STANDARD HYDRAULIC BRAKES cylinders exert a force on the shoes moving
them against the brake drums. When the
Standard hydraulic brakes are usually found
on automobiles and light trucks. They operate brake pedal is released, the wheel cylinder
on the basic hydraulic principle of trans- pistons are returned, by springs to their
mitting force and motion through a confined unapplied position and the fluid is returned to
fluid. the master cylinder.
Variations on the basic hydraulic brake
A standard hydraulic brake system (Figure 4-
6) consists of:
system use different numbers and
arrangements of the components. Some large
I. Master cylinder vehicles have two cylinders per wheel. Trucks
use larger cylinders and shoes on the rete
2. Wheel cylinders wheels since the load is carried on the rear of
tie truck. Cars and light trucks. on the other
3. Connecting lines hand. use larger cylinders on the front wheels
4. Brake fluid to get increased braking force in the front
shoes.

DUAL
MASTER PRIMARY RESERVOIR
CYLINDER (FRONT BRAKE SYSTEM)

MECHANICAL
STOP LIGHT
SECONDARY RESERVOIR SWITCH
(REAR BRAKE SyS QM)

WARNING LIGHT

BRAKE
IGNITION PEDAL
SWITCH REAR DRUM BRAKES
FRONT DISC
BRAKES SELF ADJUSTING

DIFFERENTIAL/PROPORTIONING
METERING VALVE
HIOSSI
(4-6) HYDRAULIC BRAKE SYSTEM
MANUAL BRAKES
Courtesy of Ford Motor Company

223
 BRAKES 4:5

FOUNDATION BRAKE shoe return springs and shoe holddown

parts
Drum brakes and Disc brakes are the two
major types of wheel brakes used on cars, a means of adjusting the shoes to com-
light trucks, and heavy duty vehicles. pensate for lining wear
a drum
DRUM BRAKES
The drum brakes on the rear of most
A typical drum brake (Figure 4-7) includes: passenger cars and light trucks also normally
include the additional parts required for
a backing plate or support plate parking brakes.
two lined brake shoes attached to the
backing or support plate

WHEEL CYLINDER BACKING PLATE

PRIMARY SNOE SECONDARY SHOE CABLE GUIDE

ADJUSTER CABLE

ADJUSTER LEVER
SPRING

I OJUSTER
LEVER

PARKING
PIVOT
BRAKE STRUT

ADJUSTING NUT
ADJUSTING SCREW

SHOE HOLDDOWN PARTS

AUTOMATIC ADJUSTER PARTS
P.2460740

(47) TYPICAL DRUM BRAKE Courtesy of Bendjx Corporation

(DUOSERVO TYPE)

There are two main types of drum brakes. Duo- On a duo-servo brake, the shoe toward the
Servo and Non-Servo. front of the vehicle is called the primary shoe,
and the shoe toward the rear is called the
DUO-SERVO BRAKES secondary shoe. The primary shoe normally
has a shorter piece of lining than the secon
The distinguishing feature of a duo-servo dary,
drum brake is that a single anchor holds the
shoes at their upper ends and the shoes are
linked together at the bottom ends by an ad-
justing screw.
The duo-servo brake obtains its name from
the servo principle of brake action which was
introduced in the late twenties. During a brake
application, each shoe serves the other. and
the motion of the vehicle actually helps to ap-
ply the brakes.

224
4:6 BRAKES

When a vehicle with duo -servo brakes is ANCHOR PIN

moving forward and the brakas are applied.
the brake shoes are forced outward into the SECONDARY
rotating drum. As the linings contact the SHOE
drum, the primary shoe tends to move in the
direction of drum rotation as shown in Figure
4-8. The upper end of the primary shoe is
pulled away from the anchor pin. (The shoe
has room to move on the pin.) The force
p:oduced by the tendency to rotate with the
drum is transmitted from the primary shoe
through the adjusting screw to the secondary
"PRIMARY
shot. The result is that the secondary shoe is SHOE
forced into tighter contact with the drum, and
brake efficiency is greatly increased. FORWARD BRAKING
During reverse braking, the upper end of the
secondary shoe pulls away from the anchor ANCHOR PIN
pin and helps to apply the primary shoe.
SECONDARY
SHOE
Duo-Servo brakes often have an automatic ad- PRIMARY
justing mechanism. The automatic adjuster SHOE
uses the action of the brake shoes during a
reverse brake application to adjust the brakes
if an adjustment is required. During a reverse
brake application. the secondary shoe tries to
rotate with the drum. and the upper end of the REVERSE BRAKING
shoe moves away from the anchor pin. This (4-8) DUO-SERVO BRAKING ACTION
places tension on the cable. and the cable Courtesy ol Bericfni Corrioration
pulls the adjuster lever upward. The amount of
lever movement depends on how far the
secondary shoe moves away from the anchor
pin. If the lining has worn enough to require
adjustment. the shoe movement will be suf-
ficient to cause the lever to engage the next
tooth on the adjusting screw star wheel.
ANCHORS
S-SHAPED
iCAM

(4 -9)
NON-SERVO BRAKES

Courtesy of Grey Rock Onn SiOn of

RaybeSto$ Manhattan Inc
NON-SERVO BRAKES
On Duo-Servo brakes the two brake shoes
have an interrelating braking action (in effect
one shoe serves the other). On Non-Servo
brakes each shoe has a separate anchor and
the shoes act independently against the drum.
Non-Servo brakes are actuated by a hydraulic
cylinder or a cam (s-shaped or flat). A retrac-
Courtesy of Grey Rock. Division of ting spring holds the shoes together against
RaybeStos Manhattan Inc. the activator (Figure 4-9).

225
 BRAKES 4:7

The shoe which is first in direction of rotation

on non-servo brakes is referred to as the
primary shoe; the other is the secondary shoe.
Often dif;erent types of lining material are
used on the two shoes to improve the braking
action.
Non-servo brakes actuated by hydraulic cylin-
ders usually have separate adjusters for each
shoe. Those having cam actuators are ad-
justed by a slack adjuster (discussed later).

DISC BRAKES
Disc brakes are becoming more common on
modern automobiles and trucks. There are
two main types of disc brakes: caliper disc
brakes and multi-disc brakes.
CALIPER DISC BRAKES
Caliper disc brakes (Figure 4-10) have:
a disc or rotor that is secured to and
rotates with the wheel hubs.
a caliper assembly that squeezes the
rotor on both sides to give the braking
action. There are three designs of
calipers: fixed. floating and sliding (4-101 TYPICAL FIXED CALIPER DISC BRAKE
calipers. Coulter, of Swint Corporation
hydraulic wheel cylinder(s) or air to ac-
tivate the caliper.

ADVANTAGES OF CALIPER DISC BRAKES MULTI-DISC BlAKES

Disc brakes offer three major advantages over Multi-disc brakes have Lcen used for some
conventional drum brakes. time on heavy equipment such as wheel
loaders. large haulage trucks and graders.
1. Resistance to Heat Fade. Disc brakes are Each brake has a number of smooth faced
generally more resistant to heat fade stationary discs splined to the wheel hub. The
during high speed brake stops or repeated rotary discs fit between the stationary giving
stops. The design of the disc brake rotor an alternating pack of rotating and stationary
exposes more surface to the air and thus discs. Braking action occurs when the
dissipates heat more efficiently. stationary discs are compressed against the
rotating discs. Disc activation is by air or
2 Resistance to Water Fade. Disc brakes hydraulics. The discs are generally oil cooled
also are affected very little by water fade to help prevent the brakes from fading.
because the rotation of the rotor tends to
throw off moisture.
3. More Straight-Line Stops. Due to their POWER-ASSISTED HYDRAULIC BRAKES
clamping action. disc brakes are less apt There are three types of power-assisted
to pull and generally produce more brakes in common use today.
uniform straight-line stops.
Vacuum
A number of truck manufacturers are using
caliper disc brakes as original equipment and Air-over-oil
its quite conceivable in the near future that Oil-over-oil
most trucks will be using disc brakes.

226
4:8 BRAKES

Why are power-assisted brakes necessary? booster is frame mounted away from the
master cylinder; its control valve is operated
1. Large vehicles require greater braking by hydraulic pressure from the master cylin-
forces than manually operated brakes can der.
supply.
POWER BOOSTER OPERATION
2. Vehicles travelling at higher speeds
require power brakes for a similar reason. An integral booster consists of a power sec-
tion. a master cylinder section. a vacuum line
3. Power brakes are easier to operate from the intake manifold and a brake pedal to
requiring less effort from the driver. operate it. as shown in Figure 4-11.
All three types of power-assisted brakes The power section is a vacuum chamber (the
operate according to a hydraulic principle vacuum is created by the intake manifold)
similar to standard hydraulic brakes. The dif- divided into two by a piston or a diaphragm. In
ferelce between the two is that power- the centre of the piston is a control valve. In
assisted brakes have an additional released position the control valve is open
mechanism that increases the braking force. and a vacuum exists on both sides of the
piston. A slight movement of the brake pedal
VACUUM-ASSISTED BRAKES closes the control .valve. Atmospheric
pressure (air) is then fed into the rear of the
Vacuum-assisted brakes use a vacuum brake piston. Since the pressure in air is greater
booster to increase the braking force of a than in a vacuum, the air will force the piston
conventional hydraulic brake system. into the vacuum. Thus the piston is pushed by
Boosters are standard equipment on all large the atmospheric pressure trying to take up the
trucks with hydraulic brakes and on many vacuum. The piston in turn pushes on the
light trucks and automobiles. Truck boosters master cylinder which activates the wheel
are commonly referred to as Multiplier cylinders. What has happened is that 4 slight
boosters (Hydrovacs), and automobile force on the brake pedal has resulted in a
boosters as integral boosters. strong force being applied to the brake
Integral and multiplier boosters operate master cylinder. The actual force on the
similarily, but are mounted differently. The In- master cylinder would be equal to the at-
tegral booster is firewall mounted directly to mospheric pressure on the booster piston
the master cylinder; its control valve is times the surface area of the rear of the piston
operated by the brake pedal, The multiplier (Force = Pressure x Area).

me-FIREWALL

MASTER CYLINDER ---s.

VACUUM HOSE

INTAKE D
"4"".'-BRAKE PEDAL

) --.)
POWER SECTION VALVE ROD

0.24613749

(4-11) FLUSH-MOUNTED MASTER-VAC

Courtesy 01 Bench* Corporation

227
 BRAKES 4:9

The multiplier booster or hydrovac functions

in a similar way except that its control valve(s)
are operated by hydraulic pressure from the
master cylinder. Figure 4-12 shows a split
hydraulic brake system with dual hydrovac
boosters. Figure 4-13 shows a hydrovac in
detail. 0-12)
WWI ATARIFOLO VACUUM UWE Is
Mg%

CLEAR

NER 111

0. MARINO LIGHT

oottco
sotto
OIF I faEldnAu
MoRORTscR000r AMER
4111MEME1
VALVE

111011%

hi
YAMPA
U II
Cola
VALVE
VVEAHEC"ALCICVE

U VACUUM
ROOSTERS 11

FRONT (IRAQ S RAuEAR EIRMIES

AUTOMATIC ISTORAVLIC PRESSURE -WCYL, TO NoSTERS rOmATIC
AI:MUSTERS NOSTRILS TONSILS ADJUSTERS
doloOvVie - AIR CLEANER To NoSTERS
Nolo SUPPLY Tomo -Nog ANEW) TO NOSTRILS
11 I is . FRONT *RAKES ONLY Courtesy of Ford Motor Company

DIAPHRAGM VACUUM
POPPET
ATMOSPHERE
POPPET

4....--ATMOSHPERE
TUBE

PORT TO
WHEEL BRAKES

BALL CHECK VALVE

(CLOSED) RESIDUAL
HYDRAULIC PRESSURE
PISTON CHECK VALVE
PISTON STOP (4-13)
HYDROVAC IN THE APPLYING POSITION
PISTON
POWER PUSH RETURN Courtesy of Grey Rock. Division of
PISTON ROD SPRING Raybestos Manhattan Inc.

228
 4:10 BRAKES

AIR-OVER-OIL BRAKES they have only a small line leading to each

(also called Air-Over-Hydraulic) wheel assembly: and are therefore less likely
to be damaged.
Air-over-hydraulic brakes are essentially con-
ventional hydraulic brakes that are power-
assisted. Power assist is gained through the
power cluster (Figure 4-14). A power cluster is
an air cylinder joined to a standard hydraulic
master cylinder. Air pressure is applied in
graduated amounts to the power cluster by a
foot operated valve. The air pressure activates
the air cylinder in the cluster which in turn ap-
plies force to the master cylinder. The master
cylinder then sets the hydraulic system in
motion to apply the brakes.
AIR Courtesy of Wagner Electric
INLET "..,................

0 t
P25247CC

/ (4-15)
NYDROBOOST HYDRAULIC SCHEMATIC
..&-:,... Courtesy of Bendix Corporation
9Iblial..
,

lr.

MOUNTINGb.
BRACKET ,...1.
HYDRAULIC
(4-14)POWER CLUSTER WITH HYDRAULIC OUTLET
CYLINDER AND AIR CYLINDER POWER SECTION OIL-OVER-OIL BRAKES
Power clusters are capable of producing a With the help of a booster assembly equipped
pressure ratio increase of 15 : 1. For example. with an accumulator. oil-over-oil brakes corn-
100 P.S.I. air pressure applied to the air cylin- bine hydraulic pressure from a power steering
der will create 1.500 P.S.I. master cylinder out- system with a conventional hydraulic brake
put. system. The accumulator is a safety system
that supplies enough fluid to stop the vehicle
Air-over-hydraulic systems differ in the num- when the engine stalls, Figure 4-15 shows an
ber of power clusters and differ. as do most oil-over-oil brake system.
hydraulic systems. in the number of wheel
cylinders size of lining and diameter of brake Pushing the brake pedal. opens a control
drums. valve in the power booster and pressurized oil
from the steering system enters the booster.
Airover-hydrauliC brakes are often prelerred This oil pushes the piston in the booster
to air brakes on larger off-highway vehicles which in turn applies force to the master cylin-
such as trucks and loaders because the air- der. The master cylinder then sets the
_ _____ovel-Ctil _brakes are less. .vu In erable to rough
terrain. Air brakes have a number of relatively
hydraulic system in motion to apply the brake
shoes. Note that there is no mixing of steering
large exposed parts that would be subject to fluid and brake fluids. The oil from the
damage by the uneven. rocky ground that off- steering system stops at the power booster: it
highway vehicles work in. Air over hydraulic does not mix with the brake fluid from the
brake& on the other hand. are more compact: hydraulic brake system.

229
 BRAKES 4:11

Power boosters in oil-over-oil brakes, like If the spring is compressed. it then has poten-
power clusters in air-over-hydraulic brakes. tial energy which can be put to work. Com-
are capable of producing a high increase in pressed air has a similar work potential
force with a minimum effort from the operator. (Figure 4-17).
Oil-over-oil brakes should not be confused
with straight hydraulic brakes such as those
found on a cat loader. These brakes may ap-
pear to be power-assisted but they are not;
they use pressure from the machine's
hydraulic system in graduated amounts to ap-
ply the brakes,
The common name for oil-over-oil brakes is
hydro-boost brakes. Hydro-boost brakes are
used by General Motors on some of their light p.
to mid-weight trucks. Larger trucks that use
oil-over-oil brakes have an emergency system
other than an accumulator in case the truck
engine stalls An electric motor will cut in and
run a hydraulic pump. allowing the vehicle to
be safely braked. (4-17) Courtesy of Bendix CorPoratton

AIR BRAKES
Air brakes are the most common brakes used
on both on-highway and off-highway trucks
and trailers. Many types of construction
equipment too numerous to mention also use
air brakes. Air brakes transmit force and
motion through compressed air. Compressed
air is defined as air that is forced to occupy a
space less than it normally would in the at-
mosphere. Atmospheric air pressure at sea
level is 14.7 P.S.I. Compressed air is measured
in P.S.I. above atmospheric pressure. For
example. a compressed air measurement of 50
P.S.I. means 50 P.S.I. above standard at-
mospheric pressure of 14.7.

The energy of compressed air can be com-

pared to the energy of a coil spring. A coil
spring in its free state and a container full of
air at atmospheric pressure have no potential
energy (Figure 4-16).

(4-16) CourtesY of Bendix Corporation 230

A
4:12 BRAKES

A standard air brake system (Figure 4-18), is 6. Brake Chambers receive the gradu-
made up of the following components. ated amounts of compressed' air and con-
vert it into the mechanical force and
1. Compressor pumps air under pressure movement needed to apply the brakes.
into the reservoir. It is driven, cooled and
lubed by the main engine. 7. Slack Adjuster part of the mechanism
that applies the force from the brake
2. Reservoirs receive and store the com- chamber to the brake shoes. Slack ad-
pressed air. justers also provide the means to adjust
3. Governor controls the air in the reser- air brakes to compensate for normal run-
voirs. ning wear.

4. Valves control the application and 8. Foundation Brake Assemblies supply

release of the brakes. the braking action.

5. Safety Valves protect the tractor and

trailer air supply in case of an emergency.
TRACTOR PROTECTION TRAILER
CONTROL VALVE VALVE BRAKE CHAMBERS

SAFETY VALVE

FRONT
BRAKE CHAMBER

00 0
HANO VALVE
COMPRESSOR
EMERGENCY
covcmcH

TEE OR QUICK
TEE OR QUICK RELEASE VALVE
RELEASE VALVE

FRONT OF
TRACTOR
BRAKE
VALVE

REAR
TRACTOR BRAKE CHAMBER TRAILER
Courtesy of Grey Rock. Division of
Raybestos Manhattan Inc.

Many improvements have been made on this

basic air brake design. For example changes
in piping (referred to as schedules) have
made a faster acting brake that has a greater
degree of safety. Such improvements to the
PUSH ROD
basic design will be dealt will' in later cour-
ses. The present material is only concerned
with a star.dard air brake system.
The wheel assembly is the most likely area of
the air system you will be involved with at this
level of training.
DIAPHRAGM
The brake chamber shown in Figure 4-19
illustrates the action that takes place at the
wheel assembly. Air enters the chamber at SLACK ADJUSTER
point (A) and acts against the diaphragm to
move the push rod against the slack adjuster.
(4-19) Courtesy of Grey Rock. Division of
Raybestos Manhattan Inc.

231
 BRAKES 4:13

Turning to Figure 4-20, the slack adjuster

rotates the cam shaft which forces the shoes
out against the brake drum. When air is
released from the brake chamber, return
springs in the brake assembly and in the
brake chamber move all the parts to released
BRAKE CHAMBER
position.

SLACK ADJUSTER
BRAKE DRUM*.

4: :"

4: eNt' 4

ADJUSTING NUT

BRAKE CAM

0 CAM ROLLER

AXLE
--BRAKE SHOE

RETURN SPRING
Courtesy of Grey Rock. Division of
(4-20) Raybestos Manhattan inc.

EMERGENCY OR PARKING BRAKES

RIGHT REAR
An emergency or parking brake is standard
equipment on all vehicles. It may be a
separate braka on its own, i.e., a drive shaft
parking brake, or may be an integral part of PARKING BRAKE PEDAL
the service brakes.

INTEGRAL PARKING BRAKE

Integral parking brakes (Figure 4-21) are con-
trolled by a brake pedal or hand lever and
cables. The cables operate mechanical levers
which force the service brake shoes against CABLE
the drum. EQUALIZER

Since integral parking brakes are primarily LEFT REAR

used on automobiles arid light trucks. they
won't be dealt with any further here. (4-21) TYPICAL INTEGRAL PARKING BRAKE
p.240744
Courtesy of Bendix Corporation

232
4:14 BRAKES

DRIVE SHAFT PARKING BRAKES

Drive shaft parking brakes are mounted at the
rear of the transmission where the drive shaft
is connected to the output shaft. These "0 PARKING BRAKE LEVER
parking brakes are mechanically applied by a
hand lever connected to cables or rods. CABLE
Figure 4-22 shows an external band drive
BAND AND LINING
shaft parking brakb.

P24607.43

Three common types of drive shaft parking

brakes are:
TRANSMISSION CASE o-
1. Internal expanding shoe parking brake
(Figure 4-23). Note the control lever (4)
that applies the brake and also note the (4.22) EXTERNAL BAND PARKING BRAKE
adjusting screw (10). Courtesy of Bendix Corporation

3 External contracting band parking brake

4 5 2.
(Figure 4-24). Note that the brake band is
outside of the drum.
1

18 3
19 4

S
--

-
6 17 4,1

16
4 6

14 7
.7
11
8
7
10 9 8

9
Return Springs 7 Brake Shoe 13 10
12 11
2 Anchor Pin Link 8 Plate Bolt
3 Camshaft 9 Adjusting Screw 1 Brake Band 11 Lock Nut
4 Control Lever Spring 2 Cams 12 Lock Washer
5 Link 10 Adjusting Screw 3 Links 13 Brake Linings
6 Relay Lever 11 Support Plate
4 Clevis Pins 14 Release Springs
5 Cam Shoe 15 Brake Drum
(4.23) INTERNAL EXPANDING BAND 6 Lock Nut 16 Adjusting Bolt
PARKING BRAKE 7 Adjusting Nut 17 Anchor Bar
8 Locating Bolt 18 Anchor Screw
Courtesy of General MOrtOrS Corpoation 9 Washer 19 Lock Wire
10 Adjusting Nut

(4-24) EXTERNAL CONTRACTING BAND

PARKING BRAKE

233
 BRAKES 4:15

3. Disc and pads (Tru Stop) (Figure 4-25). (4-26) HOW THE SPRING BRAKE WORKS
Note the disc 12 between the two brake
shoe friction pads (9) and (10). This disc
and pad construction is a very effective
parking brake and is used on many
vehicles.
1

trso
of
44 e .-
3
4

Normal Brakes Released

Mr pressure from service system acting on
the piston compresses the spring. releasing
the brakes.

01(4(7quiliii6o6
-

16 14
16
a k fr
17
le no
1 Brake Suppon 8 Brake Shoe Pin
Bracket 9 Front Brake Shoe
2 Parallel Adjusting 10 Rear Brake Shoe
Screws 11 Front Lever Arm
3 Front Lever Arm Pin 12 Brake Disc Service Brake Application
4 Pin Retaining Screw 13 Tension Spring
5 Brake Cable Clews 14 Spring Air pressure from the service brake system
6 Brake Lever 15 Rear Lever Arm acts on the diaphragm applying the brakes.
7 Brake Shoe Pin 16 Adjusting Nut
Retainer 17 Tie Rod
(4-25) TRU-STOP TYPE PARKING BRAKE
Courtesy of General Motors Coroorairon

SPRING BRAKES
Vehicles with air brakes may have a drive
shaft parking brake. but they are more likely
to have spring brakes. Spring brakes could be
referred to as integral parking brakes be-
cause they work on the service brake shoes.
There are a number of types of spring brakes
but they all operate on the basic principle of
spring applied and air released. Once applied, Parking Brake Application
the brakes cannot be released until sufficient
air pressure is fed into the chamber to retract Exhausting the air from the chamber releases
the spring. Spring brakes are very positive the piston, allowing the spring to force it and
and very safe. Operation of a typical spring the push rod forward, applying the brakes.
brake is illustrated in Figure 4-26. Courtesy ot the Government ot &dish Columbia
Artbrake Manual

234
4:16 BRAKES

BRAKE FLUID CHANGING BRAKE FLUID

Brake fluid is one of the more important com- Due to Usage
ponents of the hydraulic brake system be-
cause it ties all the other components of the Through use. brake fluid loses some of its
system together into an operating unit
original qualities and may become con-
Hydraulic brake fluid is a specially blended taminated. When performing major brake
liquid that provides a means of transmitting work. it is good practice to flush the hydraulic
hydraulic pressure from the master cylinder to system to remove old fluid and replace it with
the wheel cylinder. The fluid is a composite of clean brake fluid. Also. if any of the hydraulic
glycerine alcohol and performance additives system parts are corroded or the fluid is
It is important to note that brake fluid is not a discolored. the hydraulic system should be
petroleum product and should never be mixed flushed and filled with clean brake fluid.
with oil. Brake fluid and oil are incompatible.
Any oil added to brake fluid in a hydraulic Due to Contamination
brake system would quickly destroy the Soft or swollen rubber parts in the hydraulic
system's rubber parts. For this reason it is a system are an indication that the brake fluid is
good habit to refer to the fluid in a brake contaminated. If this happens:
system as brake fluid and not brake oil.
the old fluid should be drained from the
Having cautioned against the use of the term system.
brake oil. an exception must be mentioned By
far the majority of hydraulic brake systems all cups and seals should be replaced.
use brake fluid. but there are a few that use the hydraulic system should be Hushed
oil. For example. large mine haulage trucks with clean brake fluid or alcohol.
use a petroleum based oil in their hydraulic the system should be refilled with clean
brake systems. brake fluid.
Federal laws require that brake fluid must
meet SAE (Society of Automotive Engineers) HANDLING AND STORING BRAKE FLUID
specifications The current SAE specification
for Brake Fluid is J1703. Fluids used should The following basic rules should be followed
meet or exceed this standard. when handling and storing brake fluid.

the following 1. Keep the brake fluid clean. Do not get any
Brake fluid must possess
characteristics: foreign material in the fluid.

1. Viscosity (free flowing at all tem-

2. Be very careful to keep any petroleum
product (gasoline. kerosene. oil. grease,
pe ratu res).
etc..) from getting into the brake fluid.
2. High boiling point (remain liquid at
highest operating temperature). 3. Use only clean containers for dispensing
brake fluid. Do not use containers con-
3. Non-corrosive (must not attack metal or taminated with dirt. oil. grease, rust. etc.
rubber parts).
4. Always cover or cap brake fluid con-
4. Water tolerance (must be able to absorb tainers when not actually dispensing the
and retain up to 2% moisture that collects fluid. If containers are left open or ion
in the system). covered. the fluid tends to absorb
moisture from the air.
5. Lubricating ability (must lubricate piston
and cups to reduce wear and internal fric- 5. Discard old brake fluid drained from the
tion). hydraulic system. Used brake fluid is con-
taminated to some degree.
6. Low freezing point (must not freeze even
at lowest operating temperatures). 6. Store brake fluid containers in a clean. dry
place.

235
 BRAKES 4:17

QUESTIONS BRAKES 12. What are the three main parts of a

caliper disc brake?
1. Brakes convert a vehicle's motion energy
into: 13. What does the oil-over-oil Hydro-Boost
power brake system use as a source of
(a) drag energy assist?
(b) friction energy
14. Air brakes work on the principle of trans-
(c) heat energy mitting force and motion through the
(d) all of the above medium of:
2. The strength of frictional force between (a) compressed fluid
two surfaces is called their (b) compressed air
(c) compressed fluid and air
3. What are two vehicle operating practices (d) none of the above
that can be very hard on brakes?
15. Spring brakes operate on the principle
4. What are the three types of brake of:
systems used on heavy duty vehicles?
(a) air applied and spring released
5. Hydraulic brakes work on the basic prin-
ciple of transmitting force and motion (b) spring applied and air released
through the medium of: (c) spring applied and hydraulic
trapped air released
(a)
(d) spring applied and spring released
(b) hydraulic lines
(c) a confined fluid 16. Is the fluid used in the majority of
hydraulic brakes a petroleum product?
(d) all of the above Briefly describe the composition of brake
6. In a hydraulic brake system what hap- fluid.
pens to the flow of pressurized fluid that 17. What does the phrase bleeding the
the master cylinder sends out to the brakes refer to?
wheel cylinder to apply the brakes.
7. List the three common types of power-
assisted hydraulic brakes.
8. Briefly explain the differences between
an Integral and a Multiplier vacuum
assist brake system. Give an example
where each is used.
9. Briefly explain the difference between a
duo-servo and a non-servo foundation
brake.
1U. In an air-over-oil hydraulic brake system.
what applies force to the master cylinder
setting the hydraulic system in motion to
apply the brakes:
(a) air reservoir
(b) air compressor
(c) air cylinder or power cluster
(d) none of the above
11. An advantage of multi-disc brakes is that
the disc can be _ in
oil,

236
4:18 BRAKES

PREVENTIVE MAINTENANCE AND BLEEDING HYDRAULIC BRAKES

ADJUSTMENTS ON BRAKES
Hydraulic braking systems will only work if
Good preventive maintenance practices on they are free of air. Whenever work is done on
brakes is essential since brakes are so im- the wheel or master cylinders, air gets into the
portant to the safe Operation of a vehicle. As a system and has to be released Each wheel
first year apprentice you will likely do brake cylinder has a bleed valve and some master
checks and adjustments. and make minor cylinders also have one. Figure 4.27 shows
brake repairs. Until familiar with the location typical bleeding points.
and number of adjusters and adjusting
procedures read the service manual before
attempting to make any brake adjustments.
BLEED AT MASTER
CYLINDER OUTLETS
= v - -----

BLEED AT BLEED AT EACH

EACH CALIPER WHEEL CYLINDER

(4-27) TYPICAL BLEEDER POINTS

Courtesy 01 Bend's Corporation

There are two methods of bleeding:

1. Manual bleeding
2. Pressure bleeding
To manually bleed a hydraulic system first fill
the reservoir. Then while one person slowly
pumps the brake pedal. another person opens
each bleeder. one at a time. to free the air.
Use a bleeder hose and a glass jar to collect
the fluid. as shown in Figure 4-28.
Press slowly on
brake pedal.
MASTER CYLINDER .

REAR BRAKE

BLEEDER HOSE

GLASS JAR
(4.28) MANUAL BLEEDING
P251620
Courtesy of Berdix Corporation

237
 BRAKES 4:19

To pressure bleed a hydraulic system connect

a pressure bleeder tank to the master cylinder
(Figure 4-29) and then open one bleeder at a
time to free the air. Again. collect the fluid in a
glass jar.
ADAPTER

REAR BRAKE

*""" BLEEDER NOSE

"6 GLASS JAR

PRESSURE 5LEEDER
TANK
P.251620
(4-29) PRESSURE BLEEDING
Courtesy of Bendy( Corporation
If at any time a brake line has to be discon- 5. Tighten the adjustment until the wheel will
nected. be sure to clean the area around the not rotate. and then back it off until the
fittings before disconnecting it. Cap the line wheel is free and a very slight drag is felt.
once it is unfastened. As a rule the system will
Be sure you know how many adjusters are
require a slight bleeding when the line is used on each wheel. Some wheels have
reconnected. To complete the job of bleeding
two adjusters. one for each shoe. Also
the brakes, one Person should pump the watch for adjustable anchors (a threaded
brakes while another person checks for leaks. bolt with a lock nut projecting from the
backing plate) on some brake systems. Do
ADJUSTING HYDRAULIC BRAKES not adjust these anchors: they are ad-
Not all brakes require adjusting; some are self justed only after a major brake overhaul.
adjusting and some require no adjustment.
Brakes that do require adjustment need to The following figures show some of the
have the wear on the brake linings com- methods used to adjust hydraulic brakes. A
pensated for. The frequency of adjustment manual adjuster. as shown in Figure 4-30,
depends on the condition and type of brakes, usually has an access hole in the backing
the type of work the vehicle is doing, and the plate. A hook shaped tool fits through the hole
operator (some operators are harder on and turns the adjuster wheel.
brakes than others).

GENERAL POINTS ON BACKING

BRAKE ADJUSTMENT PLATE -"--41"
1. Determine the need for adjustment by
checking the amount of Pedal travel. If the
pedal travels more than half way to the
floor. adjustment is usually indicated.
2. Park the vehicle on a level area.
3. Block one front wheel and one back
wheel for safety.
ADJUSTING TOOL
4. Jack up one wheel at a time so each STAR WHEEL
wheel can be rotated while it is being ad- Itx.........
justed. 4607.26
(4-30)
Courtesy of Elendix Corporation

238
4:20 BRAKES

Some self adjusters may require an initial Figure 4.32 shows a large wheel assembly
adjustment. or may have to be adjusted that has a star wheel brake adjuster.
manually if they are not self adjusting Probably there is another adjuster located
properly. They can be adjusted by holding 180 from this one.
the internal adjusting lever away from the
star wheel. and then turning the wheel
with a hook shaped tool. The method of WHEEL
holding the adjusting lever away from the CYLINDER BOLTS
wheel will depend on where the access
hold or adjusting slot is located (Figure A JU TII
4-31). TOOL

4..
BACKING PLATE

BLEEDER VALVE
ADJUSTING TOOL
CONNECTOR
TUBE

ADJUSTER
LEVER

STAR WHEEL
SCREWDRIVER
P.24607.26

WITH ADJUSTING SLOT IN

(4-31)
BACKING PLATE REAR AXLE
Courtesy of Bendix Corporation BRAKE LINE

BACKING PLATE DRUM T2939

ADJUSTER (4 -32)
LEVER Courtesy of General Motors Corporation

HOOK
TOOL

STAR WHEEL ADJUSTING TOOL

P.24607.26

(4.31) WITH ADJUSTING SLOT IN

BRAKE DRUM
Courtesy of Bendix Corporation

239
 BRAKES 4:21

The wheel assembly in Figure 4-33 uses a lid. This practice will prevent dirt from get-
stud adjuster. The direction that the stud ting into the fluid. Figure 4-34 shows
is turned to adjust the shoes will vary (see various types of reservoir filler caps and
service manual). Note there are two studs. lids. FILLER CAPS
one for each shoe.

--- FRONT SHOE

ADJUSTING STUD

WHEEL CYLINDER
BOLT

LEED
VALVE

.,,---- RESERVOIR COVER

AP
1

COPPER (4-34)
GASKETS

RESERVOIR COVER RETAINER BOLT

,
CONNECTOR
TUBE

REAR SHOE
ADJUSTING STUD (4-34)
1.2938 RESERVOIR 1124607-43
DIAGHRAGM RESERVOIR COVER
(4-33)
RETAINER COVER
Counesy of General Motors Corporation

6. While making brake adjustments. be ob-

ITEMAirr=1 ROD RETAINER
servant for damaged lines. leaks. etc. If a
brake line has to be disconnected on a P448074
machine such as a wheel loader which
has full hydraulic brakes and an ac-
cumulator. be sure to shut the engine
down and apply the brakes several times
to bleed the accumulator. This practice is usy gooT PUNS ROD
to prevent you from being showered with (4-34)
Courtesy of Bendix Corporation
oil. Similarly bleed down the accumulator
on an oil-over-oil system and the air from Note that all current master cylinder reser-
an air-over-oil system. voirs have a diaphragm across the top of
the fluid to prevent air from getting at the
7, After the brake adjustment is completed. fluid. The diaphragm is necessary be-
always check the fluid level. If the level is cause brake fluid has an affinity for taking
down. clean the area around the top of the moisture from the air. The diaphragm is a
reservoir before removing the filler plug or soft flexible membrane which follows the

240
4:22 BRAKES

fluid level as it goes down in the reservoir. or slightly greater. as shown in Figure 4-
The membrane keeps air away from the 35. When the angle is less than 90° there
fluid, but still allows a normal atmosphere is too much push rod travel and the slack
pressure above the fluid. adjuster should be adjusted.
Brake fluid can be topped up. if low with ANGULAR ADJUSTMENT
the approved brake fluid. However. if very (Brake Applied)
much fluid is needed. it's quite possible
there is a leak. Normally. little brake fluid .1P.,,,,
has to be added and it shouldn't have to
be added very often. -, (4-35)

If the vehicle is equipped with vacuum-

assist power brakes. a quick method to
check booster operation is as follows: Co\unesy 0
Wagner COFOOtat1011
(a) Before starting the engine, pump the
brake pedal several times to exhaust Having found the applied push rod and
all the vacuum. slack adjuster angle is less than 909. the
most accurate method of correcting them
(b) Hold your foot firmly on the brake is to:
pedal. (a) Jack up the wheel. as was done with
hydraulic brakes.
(c) Start the engine. If the booster is
functioning the pedal will drop (b) Turn the adjusting nut on the slack
slightly as the engine starts. adjuster to rotate the cam anc bring
the shoes in contact with the drum.
Obviously. the brakes can also be Figure 4-36 shows a typical slack ad-
checked by moving the vehicle and ap- juster. Note how the worm shaft ad-
plying the brakes. juster bolt (7) turns the worm (6)
which in turn rotates the gear (8). The
ADJUSTING AIR BRAKES
gear then rotates the shaft of the cam
Air brakes. like hydraulic brakes. need to be which is splined to it.
adjusted to compensate for running wear. (4-36)
Although adjustment is important on both
types of brakes, adjustment is probably more
critical on air brakes. A driver has a chance to
counter-act faultily adjusted hydraulic brakes.
but he doesn't have the same chance on air
brakes If the pedal is low on first application
PUSH LOCK StE Eve DI tO
of a hydraulic brake. pumping the pedal will DISENGAGE NEAD Of WORM
displace more fluid which will further expand Riot tO FAME ADIUSWENE

the wheel cylinders and apply the brakes. The

brake chamber on air brakes. on the other
hand. has a specific volume and stroke and
once the maximum stroke is reached. the
brakes cannot be pumped up. For this reason
it is most important that air brakes be kept
properly adjusted. It's worth noting that very
few air brakes have failed from loss of air: the
most likely cause is that the brakes were
badly out of adjustmPre.. c.=3
LOCK SEIM MUSE CONE OW
Air brake adjustment for an S-cam brake AND ENGAGE HEAD OF WORM
should be done as follows: SNAFT TO IOCK ADAFSPAINt

Two persons are needed. one person I Lock Sleeve 6 Worm

should apply the brakes while the other 2 Spring 7 Worm Shaft
checks. at each wheel. the angle between
3 Dowel 8 Gear
the slack adjuster and the push rod of the 4 Lever
brake chamber. The angle should be 900 9 Cover Plate
5 Rubber Plug 12325
Courtesy of General Motors Corporation
 BRAKES 4:23

(c) Adjust the brake until the wheel is CHECK BELT TENSION
tight and then back it off enough to
get the shortest possible push rod if the compressor is a belt drive. check the
stroke without the brakes dragging. belt tension.
as illustrated in Figure 4-37). 1. Use a V-Belt Tension Gauge to check belt
Shed As Paula.
tension (Figure 4-39).
Without Brakes Dragging

Applied
Position
/
V -BELT TENSION
GAUGE

(4-37)
Courtesy of General Motors Corporation

DRAIN THE RESERVOIRS

Some further important service checks for air 14964
brake systems are: (449)
Courtesy of General Motors Corporation
All reservoirs have a drain cock that should
be drained after each shift (Figure 4-38). 2. Or, if a gauge is not available, place a
straight edge across the two pulleys and
SAFETY VALVE depress the belt with your thumb. The
)1( slack should be approximately 1 inch (21/2
cm).

REPLACING AIR LINES

Air brake lines are either metal tubing. nylon
tubing or flexible hose.
The metal lines are annealed copper tubing
DRAIN COCK
with a three piece compression fitting (flared
fittings should not be used for air lines). When
replacing metal lines the cut end should be
(4-38) free of burrs and the lines blown clear with
Courtesy of the Government of British Columbia compressed air; metal particles can ruin the
Air Brake Manual seating surfaces of the control valves. Make
Draining reservoirs is usually an operatrl's sure when replacing any type of line that the
new line is the same size as the one taken out.
job. but a mechanic may do it as part of a p.m.
check. Draining is necessary because air from Nylon tubing has replaced many lines that
the atmosphere has moisture which con- used to be metal. Nylon is flexible. durable.
denses and settles in the reservoir. A small and weather resistant making it suitable for
amount of oil will usually be present as well. many air brake applications. such as con-
This mixture of oil and water is milky white necting lines between stationary components
when drained. If an excessive amount of oil is and long lines that run the length of the frame
present in the drainings. trouble may be in- rails. Nylon is not suitable. though. for use in
dicated in the compressor. areas where temperatures could exceed

242
4:24 BRAKES

200 F (93 C) or for use between the vehicle 1. install the hose so that it lies naturally.
frame and moveable axle housings where the without twist
brake chambers are located. Because nylon
can be used only on certain lines. never 2. guard hose that is near heat
replace a metal line with a nylon one unless it 3. support long lines
is in an approved nylon location. When a num-
ber of nylon lines run alongside one another. After any air line has been installed. carefully
tape them together for added support and check the connections for leaks. One com-
protection. mon way to look for a leak is to put soapy
water on the connection and when the brakes
The fittings (Figure 4-40) for nylon tubing are are applied check for bubbles.
easy to install, requiring no special tools. Sim-
ply cut the line to the required length and in- ADJUSTING PARKING BRAKES
stall the fitting. Avoid tight lines or lines that
are longer than they have to be. Figure 4-41 Since parking brakes are mechanical and
shows a cut away of a nylon line connection. usually not too difficult to get at. they are
generally easy to adjust. Check the service
NUT FITTING SLEEVE INSERT NUT TUBE manual for the method of adjustment on any

&a a 4 given type of parking brake. Below are two

examples of adjustments on drive shaft
parking rakes. Be sure not to adjust the
brake too tightly because overheating can
result.
Internal expanding parking brake: adjust
_....... JIB 1.

ar----- a star wheel through an access hole in the

drum (Figure 4-42). ',

INSERT PARTIALLY INSTALLED

dlOileeze.r......m..'
(4-40) NYLON AIR LINE FITTINGS
Courtesy of General Motor's Corporation

TUBING NUT
SLEEVE
BODY
..--/ j/s"v...evvvvv. cl,

i
SYNFLEX TUBE INSERT
NYLON TUBE
(4.41) MOM
Courtesy of Bendix Corporation
(4-42)
Courtesy of General Motors Corporation
Flexible hose. or more specifically, wire braid
hose. is used for air lines between the brake
chambers and the frame and axle housings.
and for trailer connections. Flexible hose. like
nylon tubing. has also replaced some lines
that used to be metal. Wire braid hose is
available in a variety of sizes. #4. #6. #8. etc.
When making up flexible hose. be sure the fit-
tings are compatible with the hose. Follow the
same make up procedures mentioned for
hydraulic hoses with replaceable fittings:

243
 BRAKES 4:25

2. External contracting band parking brake:

three adjustments at points (1). (4) and (6)
in Figure 4-43.

V
t ------",-41

7
6
-

(4-43) PROPELLER SHAFT PARKING BRAKE

(BAND TYPE)

1 Anchor Screw 5 Adjusting Bolt

2 Locating Bolt 6 Lock Nul
3 Lock Nut 7 Adjusting NW
4 Adjusting Nut
Courtesy of General motors Corporation

A final word about brake work. Because they

are so important to the safety of a vehicle, use
extra care when working on or near brakes,
no matter how minor the task may be. A ser
vice man must be certain that the brakes are
safe.

244
,..
4:26 BRAKES

QUESTIONS BRAKE MAINTENANCE

1. What are the two methods of bleeding
brakes?
Which one is the most effective?
2. What is the most obvious indication of a
need for brake adjustment?
3. To quick check a vacuum-assist power
booster. put your foot on the brake pedal
and start the engine. The pedal should:
(a) move up slightly
(b) go to the floor
(c) go spongy
(d) drop sii:'":y
4. Adjustable anchors should be adjusted
each time that the shoes are adjusted.
True or False?
5. Briefly explain why brake adjustment is
so important on air brakes.
6. Air brakes are properly adjusted if. when
applied the angle between the push rod
and the slack adjuster is:
(a) 180°
(b) 35°
(c) 90°
(d) 70°
7. Air reservoirs should be drained:
(a) after every shift
(b) before every shift
(c) once a week
(d) all of the above are acceptable
8. What test must be made after installing
or replacing any air line?
9. If hydraulic brake fluid is discolored the
brake system should be

245
 BRAKES 4:27

ANSWERS BRAKES
1. (c) Heat energy
2. coefficient of friction.
3. over/ceding the vehicle and braking at
high speeds
4. standard hydraulic brakes, power-
assisted hydraulic brakes, full air-brakes
5. (c) a confined fluid
6. When the force on the master cylinder
piston is released. springs return the
wheel cylinder piston to its non-applied
position and in doing so push the oil
back to the master cylinder.
7. Vacuum
Air-over-oil
Oil-over-oil
8. The multiplier vacuum-assist brake is
frame mounted and the control valve is
operated by pressure from the master
cylinder. It is generally used by trucks.
The integral vacuum-assist brake is
firewall mounted and the control valve is
operated directly by the foot pedal. It is
used by automobiles and light trucks.
9. The two shoes on a duo-servo brake
have a single anchor and they have an
interrelated action against the drum. The
two shoes on a non-servo brake have
separate anchors and the shoes act in-
dependently against the drum.
10. (c) air cylinder or power cluster
11. cooled
12. Disc or rotor, caliper, hydraulic wheel-
cylinder.
13. Power steering oil pressure.
14. (b) compressed air
15. (b) spring applied and air released
16. No. Brake fluid is a composite of
glycerine, alcohol and performance ad-
ditives.
17. Forcing fluid through the entire hydraulic
system after working on it to remove the
air.

246
4:28 BRAKES

ANSWERS BRAKE MAINTENANCE

1. 1. Manual bleeding
2. Pressure bleeding
Pressure bleeding is the most effective.
2. Excessive pedal travel.
3. (d) drop slightly
4. False
5. The brake chambers have a specific
volume and stroke, and once the
maximum stroke has been reached, the
brakes cannot be pumped up. Therefore,
the stroke must be kept at a minimum.
6. (c) 90"

7. (a) after Peery shift

8. Check it for leaks.
9. flushed.

24 7
 BRAKES 4:29

BRAKE TASKS AIR-OVER-OIL POWER BRAKES

PREVENTIVE MAINTUANCE Routine Maintenance Check

SERVICE ON BRAKES 1. To check the operation of air-over-oil
SAFETY power brakes run the engine unlil the
reservoir pressure is maximum. and then
Practice safety when working with brake move the vehicle forward and apply the
systems by: brakes. The brakes should respond
quickly to stop the vehicle.
1. Chalking the wheels.
2. Applying the emergency brake before OIL-OVER-OIL POWER BRAKES
working on or near the vehicle. Routine Maintenance Check
3. Bleeding pressurized systems before
1. To check the operation of oil-over-oil
disconnecting any hoses or removing any
components.
power brakes run the engine until the
brake pressure gauge reads maximum.
and then turn off the engine. The gauge
HYDRAULIC BRAKES pressure should remain up. Apply the
Rou':ne Maintenance Checks brakes and the pressure should drop with
each application.
1. Check the brake fluid reservoir and. if low.
fill with the correct type of brake fluid. EMERGENCY BRAKES
2. Consulting the service manual. make Routine Maintenance Check
brake adjustments to compensate for nor-
mal running wear. Consulting the service manual. make
minor adjustments on an emergency
AIR BRAKES brake and lubricate the related linkages.
The service will be done correctly if the
Daily and Routine Maintenance Check emergency brake works easily and will
Following procedt.igs from hold the vehicle on an incline.
the service
manual:
1. Drain the reservoir.
2. Check the tension on the compressor
drive belt and adjust if loose.
3. Clean the compressor air filler.
4 Make brake adjustments to compensate
for normal running wear.
5. Start the engine and build up the air sup-
p ; Stop the engine. and check the
system for air leaks, repairing any that are
found.

VACUUM POWER-BRAKES
Routine Maintenance Check
1. To check the operation of vacuum power-
brakes pump the broke pedal several
times with the engine 4topped, and then
hold your loot on the pedal and starl the
engine. The brakes are working properly if
the pedal moves down slightly when the
engine is started.

248
 BLOCK

Power Trains

249
 POWER TRAINS 5:1

POWER TRAINS To do these jobs. three main parts are

needed:
BASIC FUNCTION OF POWER TRAINS
1. clutch to connect and disconnect
Power trains transmit power from the engine power.
to the drive wheels or to the tracks. The four
basic functions of power trains are: 2. transmission to select speeds and
direction.
connect and disconnect power
3. differential to equalize power for turn-
se!ect speed and torque ratios ing
provide a means of reversing the
vehicle Other parts of power trains are final drives.
torque converters, universal joints, drive
equalize power to the drive wheels for shafts, axles and retarders. Power trains for a
turning wheel loader and a crawler dozer are shown
in Figure 5-1 and 5-2.

10 6 5 4

(5-1) WHEEL LOADER POWER TRAIN

Courtesy of tmemaironal Harvester

1 Oil Cooler 6 Transmission

2 Radiator 7 Rear Lower Drive
3 Engine Shaft
4 Front Axle 8 Upper Drive Shaft
5 Front Drive Shaft 9 Torque Converter
10 Rear Axle

General Arrangement

250
5:2 POWER TRAINS

6 7
1Transmission hydraulic controls. 2Universal joint. 3 Diesel engine. 4Steering
clutches. 5Final drive. 6Range transmission. 7Torque divider. 8Track.
(5-2) CRAWLER DOZER POWER TRAIN
Courtesy of Caterpillar Tractor Co

HOW A POWER TRAIN WORKS

The first part of a power train is the clutch.
The clutch's job is to disconnect the engine
from the power train, allowing the engine to
run while the machine is standing still. The
clutch also engages this power to move the
machine.
The principle of a disc clutch can be simply
described. Think of a clutch as two discs.
each on a shall (Figure 5-3). ONLY ONE DISK IS TURNING
(5 -3)

"0" BOTH DISK ARE TURNING

Courtesy of John Deere Ltd.

25.1
 POWER TRAINS 5:3

As long as the discs are not touching. one can gear with 24 teeth. When the small gear has
spin without affecting the other. But if the made one complete revolution. it has gone a
discs are moved together when one is spin- distance equivalent to 12 teeth. The larger
ning, the other begins to turn and almost in- gear also turns through 12 teeth but this
stantly both shafts rotate as one unit. in an ac- represents only one-half a revolution.
tual disc clutch (Figure 5-4) the discs are for- Therefore. in this gear arrangement. the
ced together by strong springs. and are smaller gear makes two revolutions for every
separated by pushing down on the clutch one of the larger. In other words. the smaller
pedal. gear travels twice as fast as the larger.
FLYWHEEL CLUTCH PRESSURE PLATE SPRING COVER
DISK

TO DRIVE
FROM ENGINE WHEELS

SHAFT
CLUTCH
'AY"- PEDAL
DOWN TURNING
4 CLUTCH
m"- PEDAL
TURNING TURNING UP

NOT TURNING
FLYWHEEL

CLUTCH DISK AND PLATE CLUTCH DISK AND PLATE

DISENGAGED IN CONTACT WITH FLYWHEEL

7.
CLUTCH D1SeNGAGED CLUTCH ENGAGED
(5-4) DISK CLUTCH IN OPERATION Courtesy of John Deere Ltd

In a transmission several combinations of

smaller and larger gears are arranged so that
The next pad of the power train is the trans- the desired wheel to engine speed ratio can
mission. The transmission's function is to be selected.
change the speed of the drive wheels in
relation to engine speed. Both automobiles (5-5)
and heavy duty vehicles require a trans- DRIVING GEAR MAKES
mission. THE DRIVEN GEAR
t REVOLUTION
HAS 24 TEETH
Automobiles need more turning force on the
rear wheels to start moving than they need to
cruise along a highway. The transmission
provides this increased turning force and also
allows the engine to accelerate. The ac- DRIVEN GEAR MAKES
celeration is important because the engine 1/2 REVOLUTION
does not develop very much power at low THE DRIVING GEAR
RPM's. When the car has picked up speed. HAS 12 TEETH
the transmission increases the wheel to SMALL GEAR ALWAYS
engine speed ratio until a direct drive be- X70'I TURNS FASTER
tween the engine and the wheels is achieved. HOW THE TRANSMISSION SELECTS A SPEED
Tractors and other field machines require an
even greater turning force or torque than an Courtesy of John Deere Ltd
automobile to get traction and to pull heavy
loads.
A transmission is a system of gears. In Figure
5-5 a small gear with 12 teeth drives a larger

252
5:4 POWER TRAINS

After power passes through the transmission. 2. Gears in mesh

it travels to the differential before getting to
the rear axle and wheels. The differential, like
the transmission, is a system of gears. The
ring and pinion gears (Figure 5-6) allow the
power to turn a 90° corner from the drive
shaft, running lengthwise on the machine, to
the drive axles running across it.

RING GEAR
(5-7) GEARS
Courtesy 01 John Mere LW

r
ANION GEAR 3. Fluids (the water wheel principle)

p0.412 "TURNS /7rik

THE CORNER"

(5-7) FLUIDS
(5 -6) RING GEAR AND PINION FOR REAR AXLE Courtesy of John Deere Ltd
Courtesy of John Deere Ltd
FRICTION DRIVES
Not seen in Figure 5.6 are other differential
gears that are needed to permit the wheels to Friction drive is the result of bringing tegether
travel at different speeds when cornering. two surfaces made from materials that will
These gears are discussed later in this sec- transmit motion from one surface to the other.
tion. Slippage between the surfaces is a matter of
design and for now will be assumed to be
HOW POWER IS TRANSMITTED negligible. The engine clutch is a prime exam-
ple of a friction drive.
Earlier it was shown that clutches use friction
to transmit power. whereas transmissions and A simple form of useful friction is obtained
differentials use gears. A third way of trans- when a rubber-tired wheel contacts the
mitting power is by fluids, as in automatic ground (Figure 5-8). The friction between the
drives. These three basic ways of transmitting wheel and the ground causes the wheel to
power are illustrated in Figure 5-7. move forward when it is rotated by hand.

1. Friction (Wheels and belts).

WHEEL MOVES
FORWARD

FRICTION HERE
401°.
FRICTION (5.8) FRICTION BETWEEN WHEEL AND GROUND
X3309
(5-7) Courtesy of John Deere Ltd
Courtesy of John Deere Lid

253
 POWER TRAINS 5:5

Another friction drive occurs when two wheels GEAR DRIVES

are suspended so that their outer cir-
cumferences touch (Figure 5-9). When a Gears are the most common way to transmit
rotating force is applied to one wheel. the power. When two gears are in mesh, there is
other wilt turn. Power is transmitted from one no slippage For this reason gear drives are
wheel to the other through their frictional con- widely used for high-power applications.
tact. Note that the two wheels rotate in op- A variation on gear drive is chain drive. The
posite directions. gears (sprockets) are not in mesh but are con-
FRICTION BETWEEN WHEEL AND GROUND
nected by a linked chain which also
eliminates slippage.
BOTH FRICTION
WHEELS HERE
TURN
FLUID DRIVES
Fluid drive is both the oldest and most modern
way of transmitting power. In the past water
was used to turn a mill wheel to grind flour.
(Figure 5-11).

X2029 FRICTION BETWEEN TWO WHEELS

(5-9) Courtesy of John Deere Ud

Add a belt to the two wheels and you create

yet another type of friction drive (Figure 5-10).

to%

Ili
ail

(5.11) FLUID DRIVE IN WATER WHEEL

am* Courtesy of John Deere Ltd.
X2030 (5-10) BELT FRICTION
Courtesy of John Deere Lid

In modern times automatic drives use fluid to

When one wheel is turned. the frictional transmit power. Figure 5-12 illustrates the
coupling of the belt transmits power to turn principles of fluid coupling in automatic
the other wheel. This arrangement permits the
drives.
wheels to turn at some distance from one
another. Belt drives are more efficient than
just having the two wheels touch because the Courtesy of John Deere Ltd
belt gives more wheel surface contact area.

V.43.; (5-12) FLUID COUPLING BETWEEN TWO SHAFTS

254
5:6 POWER TRAINS

Picture A is a disc connected to a rotating slower. Thus. as gear torque increases, there
shaft. The discs contain vanes which are filled is a corresponding decrease h. gear speed
with fluid. In B the disc is rotated at high (Figure 5-14).
speed and centrifugal force causes the fluid
to move out as shown. In C a second disc is
placed above and close to the first disc. Fluid
now flows into the second disc as shown. The
force of the fluid on the second disc will
cause it to rotate in the same direction as the
first. forming a fluid coupling which transmits
power. When the discs are seated and the
fluid is under pressure. a solid coupling is for-
LARGE GEAR SMALL GEAR
med. Fluid drives. such as torque converters DRIVING SMALL DRIVING LARGER
and fluid clutches. operate according to this GEAR GEAR
basic principle. MORE SPEED
BUT LESS TORQUE
LESS SPEED
BUT MORE TORQUE

GEARS
(5-14) HOW TORQUE VARIES WITH GEARS
The basic elements of almost all conventional Courtesy of John Deere Lid
power trains are gears. Gears are simply a
means of applying twisting force. or torque. to The gears in a transmission are selected to
rotating parts. The amount of torque obtained give the operator a choice of both speed and
from a source of power is proportional to the torque.
distance from the center at which it is applied.
(The larger the distance the greater the Lower gear range = less speed but more
torque.) torque.
The principle of leverage can be used to ex- Higher gear range = less torque but more
plain gear torque. A lever (Figure 5-13) has speed.
more torque as the distance from the fulcrum
to the line of force increases (i.e.. the radius of GEAR RATIO
the applied force increases).
Gear ratio is a measure of the changes in
speed and torque in meshed gears. The for-
LEVER mula for gear ratio is:
OBJECT
8
ratio = number of teeth of driven gear
'TORQUE number of teeth of drive gear
1
In Figure 5 -15 the top gears are the drive
FULCRUM gears.
FULCRUM CLOSER TO OBJECT EQUALS
MORE TORQUE FOR LEVER
BUT LEVER MUST MOVE FARTHER RATIO 2 TO 1
RATIO 1 TO 1
(5.13) HOW TORQUE VARIES WITH LEVERS
Courtesy of Jahn Deere Ltd
15 SPEED
i15 TEETH

The radius of the applied force on the lever is TEETH 100 RPM
analogous to the radius of the driven gear.
The torque output of the gear increases as the
radius of the gear increases. In other words.
the larger the driven gear. the greater its
torque. SPEED
50 RPM
Gear torque can't be discussed without also 30
discussing gear speed. As a driven gear gets TEETH
larger the distance that the teeth must travel (5-15) GEAR RATIOS
for one revolution increases. Since this
Courtesy of John Deere Ltd
distance is greater. the gear will have less
revolutions per minute. i.e., it will travel

255
 POWER TRAINS 5:7

The gear ratio of the first set is _1 = _.1 or There are many different types of gears, each
15 1 having its own application. The four most
1.1 (read: ratio of 1 to 1). A gear ratio of 1:1 common you will encounter at this stage of
means that both gears turn at the same speed training are:
with the same torque. The gear ratio of the
1. Straight Spur Gears (Figure 5-17)
second set is) = _2 or 2:1 which means that These gears have straight teeth cut
15 1
parallel to the axis of rotation. Normally.
the drive gear travels twice as fast as the mating gears have two pairs of teeth
larger driven gear, but that the driven gear engaged at all times. These gears are
has two times more torque. 'noisy and are used mainly for slow
Consider another example: a 10 tooth gear speeds. At higher speeds spur gears tend
drives a 60 tooth gear. The gear ratio would to vibrate.
be: Uses: Straight spur gears are used in
driven gear = 60 = 6 or 6:1 devices such as hand or powered
winches. Sliding gear bans-
drive gear 10 1
missions also use spur gears for
The smaller drive gear travels six times as fast speed changes because the shape
as the larger driven gear, but the driven gear of the teeth allows a sliding gear
has six times more torque. These three exam- to easily mesh and demesh with
ples of gear ratios demonstrate the law of stationary gears.
gear operation that states: any reduction in
gear speed gives an equal increase in gear STRAIGHT SPUR
torque. (5-17)
Further information on gear ratio and torque
can be found in the first part of Chapter 47,
"Gears ". in Automotive Mechanics, Seventh
Edition.

TYPES OF GEARS
Courtesy of John Deere Ltd
Gears are normally used to transmit torque
from one shaft to another. The shafts may be 2. Helical Spur Gears (Figure 5-17) The
in line or they may be parallel or be at an teeth of helical spur gears are cut
angle to one another. obliquely across the perimeter of the gear
instead of straight across. Engagement
Gears that mesh must have teeth of the same between two teeth starts at the tooth tip of
size and design. and must have at least one one gear and rolls down the teeth to the
pair of teeth engaged at all times. Some gear trailing edge. This angular contact tends
teeth are designed to have contact between to cause side thrusts which the bearings
more than one pair of teeth. Gears are nor- must absorb. However. helicat spur gears
malty classified by: are quieter in operation, and have greater
strength and durability than straight spur
1. Type of teeth. gears because their contacting teeth are
2. Surface angle on which teeth are cut. longer.

Figure 5-16 shows two categories of gear Uses: Helical spur gears are widely used
teeth. in machine transmissions because
they are quieter at high speeds
and are durable.
HELICAL SPUR
(5-17)
STRAIGHT
CUT

(5-16) Courtesy of John Deere Lld

Courtesy of John Deere LW

25? ?
5:8 POWER TRAINS

3. Spiral Bevel Gears (Figure 5-17) These

gears were developed for use where high
speed and strength are required while
changing the angle of power flow. Their
teeth are cut oblinuely on the angular
faces of the gears The angle is deter- "e- 4
mined by the angle between the two
shafts. ......
..'" '';
Uses: Farm and industrial machines use
spiral be:el gears in ring and
pinion gear sets at the drive axles.
The ring and pinion gears not only (5-17} SPIRAL BEVEL
change the angle of power flow, Courtesy of John Deere Ltd
but also reduce speed and in-
crease the turning force.
4. Planetary Gears A Planetary gear is a
set of three gears:
Ring or Internal Gear
Planet pinions and carrier
Sun Gear
A side and end view cf a planetary are
shown in Figure 5-18. Notice how the
gears fit inside one another.

SUN
GEAR

PLANET RING OR
CARRIER INTERNAL
GEAR

(5-18)

257
 POWER TRAINS 5:9

The ring gear has teeth on its inner Two main advantages of planetaries are:
diameter which mesh with the teeth on the
planet pinions. The planet pinions are (a) the load is spread over several gears
held by the carrier and in turn mesh with reducing the stress and wear on any
the sun gear. The type of teeth used on one gear.
these gears may be straight spur or (b) a high reduction can be obtained
helical spur (as in the diagram). within a limited space.
To obtain a power flow through a planetaries are very common gear sets
planetary gear set: found on both track and wheeled
machines. Transmissions, drive axles,
(a) Hold one gear by a brake or clutch. final drives, and wheel reductions for
or by solidly anchoring it. large machines are just a few areas where
(b) Drive one gear. planetary gear sets are used.
(c) The third gear will be driven (power
output). BACKLASH IN GEARS
These three gears all remain in constant Backlash is the clearance or play between
mesh and give many speed changes and two gears in mesh. Too much backlash can be
torque outputs depending on which gear caused by worn gear teeth. by an improper
is held and which gear is powered. It is meshing of teeth or by bearings which do not
possible to get four forward speed ratios. support the gears properly. Extreme backlash
two reverse speed ratios. as well as direct can result in severe impact on the gear teeth
drive and neutral from a planetary gear from a sudden stop or reverse of the gears.
set. However. on any given planetary only Figure 5-20 shows both normal gear mesh.
one or two ratios would be used. A com- and gear mesh that permits too much
mon combination of planetary gears is backlash.
illustrated in Figure 5-19. The sun gear is
driven and the ring gear held. causing the PITCH DIAMETERS
planet pinions and thus the carrier to walk
around the inside of the stationary ring
gear. The result is a speed reduction to
the carrier. This gear combination is often
used to give a gear reduction in a final
drive.
RING GEAR
RESTRAINED

X2042
NORMAL GEAR MESH
POWER
OUTPUT
(5-20) BACKLASH IN GEARS

SUN GEAR DRIVEN

BACKLASH
(5-19) OCCURS HERE
Courtesy of John Deeere Ltd TOO MUCH BACKLASH

Courtesy of John Deere Lid

258
5:10 POWER TRAINS

On normal gears the clearance of the teeth at FRICTION DISC

the pitch diameters is very small. On worn (DRIVEN-PLATE ASSEMBLY)
gears the clearance is widened. and the
resulting backlash causes greater movement
FLYWHEEL
and impact which can bounce the gears or, at
worst, break them.

POWER TRAIN COMPONENTS

CRANKSHAFT
CLUTCHES
At this level of training the clutches you are
most likely to come into contact with are:
Disc or plate clutches
(5-21)
single disc engine clutches
double disc PRESSURE- PLATE -AND-
multi disc used in crawler COVER ASSEMBLY
steering and power Courtesy of General Motors Corporation
shift transmissions
When a clutch is engaged, the pressure plate
2 Jaw clutches used in shovel steering squeezes the clutch disc against the flywheel
causing the whole assembly to turn as one.
SINGLE AND DOUBLE DISC When disengaged, the pressure plate draws
ENGINE CLUTCHES back from the clutch disc interrupting the flow
of power from the engine to the transmission.
The purpose of the engine clutch is to con-
nect and disconnect the power flow from the The single plate clutch is generally used on
engine to the transmission so that the driver automobiles and on light trucks and industrial
can shift gears to take up the load gradually. vehicles.
The clutcn also allows the vehicle to stop A double disc clutch (Figure 5-22) has an ex-
without stalling the engine. tra friction disc and pressure plate. This
A clutch uses friction to transmit power. A second pressure plate is slotted into the
single plate clutch consists of a flywheel con- flywheel and it presses against the extra fric-
nected to the crankshaft, a friction disc tion disc. Thus more friction surface is ob-
splined to the transmission shaft and a tained within the same clutch diameter,
pressure plate assembly bolted to the flywheel making a stronger clutch. Double disc clut-
(Figure 5-21). ches are used on large trucks with high
horsepower engines.

FLYWHEEL FRONT REAR RELEASE BEARING

HQUSMG DRIVEN DISC DRIVEN DISC ASSEMBLY
STEEL
FIBER WASHER
DISC
/FIBER
DISC

------------ CLUTCH
BRAKE

INTERMEDIATE
INTERMEDIATE PRESSURE PLATE FLYWHEEL RING DRIVE PIN SET
PLATE DRIVE PM AND PRESSURE SCREWS
PLATE ASSEMBLY 4121112-A
(5-22) DOUBLE DISC CLUTCH
Both single and double disc clutches require
Courtesy Fora Motor Co adjustment to compensate for running wear.

A
1
 POWER TRAINS 5:11

MULTI DISC CLUTCHES Jaw Clutches

Multi disc clutches are used for steering on A jaw clutch (Figure 5 -25) is the simplest of all
crawler dozers and loaders. They are also clutches, consisting of two toothed jaws
used as clutch packs in both power shift facing one another, one jaw fixed to a drive
transmissions and winches. Their main ad- shaft the other to a driven shaft. When
vantage is a high holding capacity for their engaged the two shafts act as one: when
limited size. disengaged each shaft can turn in-
dependently of the other. There is no friction
A multi disc clutch consists of a set of In- involved with a jaw clutch: it is either
ternally and externally splined discs. The engaged or disengaged.
clutch is assembled with the discs placed
alternately, one lined, internally splined disc
and one unlined. steel externally splined disc 8
(the order can be reversed). JAWS
The internally splined discs fit over a hub and SHIFTING
the externally splined discs fit into a drum. COLLAR \
The discs are engaged and disengaged by
DRIVE
one of two methods: SHAFT
1. spring applied and hydraulically released,
or
2. hydraulically applied and spring released.
(5-25)
Figure 5 -23 shows an exploded view of a multi DRIVEN
disc clutch or clutch pack. Note the alternate SHAFT
arrangement of internally and externally
splined discs. A

(5-23) Courtesy 01 Clarke Equipment Co

I
Clutch packs generally run in oil and therefore
must use a type of lining material not affected
by oil. Unlike single and double disc engine
Clutches. clutch packs are not adjustable.
Figure 6-24 shows a steering clutch with the
outer drum removed. This assembly is spring
applied and hydraulically released.
r-
i

(5 -24)
STEERING CLUTCH OPERATION
1Piston. 2Pressure plate. 3Retainer.
Courtesy of Caterpi liar Tractor Co T3 41)$ I

260
5:12 POWER TRAINS

The driven jaw has a groove cut on its cir-

cumference for a shift fork to ride in. The shift
fork pulls the jaw back to disengage the
clutch and pushes it forward to engage the
clutch. Obviously jaw clutches have to be
engaged or disengaged when the machine is
stopped and the power off.
The athantages of jaw clutches are that they Colones, vo Harnoschieger Corporation POI
are cheap to make and their contact is
positive having no slippage once engaged. A L.H.
disadvantage is that jaw clutches do not SHIFTER FORK
engage and disengage smoothly.
Jaw clutches have many applications. One
you are likely to encounter is on a shovel
drive. such as show., in Figure 5-26.

(5-26) v...._ JAW

CLUTCH

R.H.
SHIFTER
FORK

Jaw clutches need no adjustments. Their only

requirement is that they be engaged fully. TORQUE CONVERTERS
A torque converter is an automatic drive using
fluids driven at high speeds and low pressure
to transmit power from the engine. A trans-
mission (i.e.. a gear train) is combined with a
torque converter to give extra speed ranges.
Acting as a clutch. the toroue converter con-
nects and disconnects power between the
17) engine and the gear train (Figure 5-27). As a
transmission. the converter gives many more
.s...ced-torque ratios than are practical with a
FLYWHEEL
mechanical gear box. No gear train could give
SHORT the infinite variations in speed and torque that
RIVE SHAFT a torque converter can.
TRANSMISSION

'NE

DRIVE AXLE COunesY 01 John Deere 11.1

261
."ffiffimiMMINNINEEINNI=IMMIENIIMI
 POWER TRAINS 5:13

TORQUE CONVERTER OPERATION

To understand how a torque converter works.
first look at a basic fluid coupling. Inside an
oil-filled housing are two parts: the driving
Courtesy of John Deere Ltd
half. or pump: and the driven half. or turbine.

irA71`1
l I

B
I
.)
C D
FLUID LIES BOWL IS SPUN TORQUE IS
LEVEL IN BOWL AND FLUID TRANSMITTED TO
SPILLS OUT UPPER BOX BY
A
FORCE OF FLUID
FLUID (5-28)
COUPLING

As the pump is turned by the engine, cen- The combined action of the two oil flows will
trifugal force causes oil to be forced radially transmit torque but not increase it. Here is
outward and because the housing is curved where the torque converter goes beyond the
the oil crosses over and strikes the vanes of basic fluid coupling: the converter can
the turbine causing the turbine to rotate in the multiply torque.
same direction. Thus the power is coupled.
A torque converter (Figure 5-30) looks much
Two types of flow are produced in the like the fluid coupling above. The main dif-
revolving coupling (Figure 5-29). The circular ference is that the converter has, in addition
flow of oil between the pump and turbine is to the driving pump and the driven turbine, a
called vortex flow. The f It i around the pump third member: a wheel of blades or vanes
and turbine that forms the coupling is called called a stator. The stator is mounted on a one
rotary flow. way clutch. When the turbine is slow or stop-
ped the stator wheel is stationary. In this
position the stator vanes change the direction
Droviag
Member
of oil flow after it has gone through the tur-
(Pump) Driven bine and sends the flow back to the pump.
Member
(Turbine)
The velocity of this returned flow is added to
the velocity already existing in the pump.
Thus. the pump velocity or output is in-
creased. In this way the converter multiplies
the torque.
Torque is increased as long as the turbine is
turning slower than the pump. This occurs
when the machine first starts to move. But as
the machine speeds up, the turbine, which is
directly splined to the transmission. also
speeds up. causing the vortex flow of oil in the
converter to decrease and the rotary flow to
increase. As the turbine approaches pump
speed. the stator free-wheels (in the same
direction) and there is no longer a torque in-
crease. Total rotary flow has been reached.
X 2199
The torque converter now acts as a single
fluid coupling sending the same torque it
(5.29) VORTEX AND ROTARY FLOW IN A receives onto the drive wheels.
FLUID COUPLING
CounesY of John Deere Lld

262
A
5:14 POWER TRAINS

Number of speeds
Number of countershafts
Location and number of transmissions
used (there are main transmissions.
auxiliary transmissions and transfer
cases).
1. The number of transmission(s) speeds will
depend on the size of the vehicle and the
C To kind of work it does.
Nye
Wheels
Light duty machines may have Three or
four speeds whereas heavy duty machines
may use one or two transmissions that
give 15 or more speeds.
2. in the past transmissions had single coun-
tershafts and this design is still used on
automobile and light trucks. However.
many heavy duty vehicles now have trans-
missions with two or even three coun-
(5-30) TORQUE CONVERTER tershafts.
Courtesy of John Deere Lid
The advantage of the multi-countershaft
The torque converter is able to automatically. design is that the torque is divided evenly
reduce or increase torque in infinitely small over two or more shafts. Dividing the
steps to match the needs of the machine and torque reduces the load on the gears.
its driver. The converter has the same effect shafts and bearings. thereby allowing the
as shifting speeds in a gear transmission ex- overall size and weight of the trans-
cept that it is done smoothly and mission to be reduced.
automatically while on the go-. Figure 5-31 shows power flow through a
The above is only a basic explanation of how single countershaft transmission. This is a
a torque converter works. simplified figure: an actual transmission
would have many more gears.
Many variations of converters are made to MAIN SHAFT
meet the demands of different machines. CLUTCH SHAFT DRIVE GEAR AND
GEAR
STANDARD MECHANICAL TRANSMISSIONS
A mechanical transmission is a train of gears
that transfers and adapts the engine power to C
the drive wheels of the machine. Usually the
transmission is located to the rear of the
engine and clutch. and in front of the dif-
ferential or ring gear. COUNTERSHAFT AND GEARS
The transmission does two jobs: (541)
Courtesy of Eaton Corporhon
selects speed-torque ratios
reverses the direction of the machine The clutch shaft drive gear turns the coun-
For information on the operation of a basic tershaft gears: the countershaft gears turn
transmission. read pages 457 to 461 (Chapter the mainshaft gears.
471 in Automotive Mechanics, Seventh
Edition.
TRANSMISSION CHARACTERISTICS
There are a number of mechanical trans-
missions. The types can be classified ac-
cording to the:

263
 POWER TRAINS 5:15

Figure 5-32 shows the power flow through

a twin countershaft transmission. In this
transmission the clutch shaft drive gear
turns two countershafts.
TWIN COUNTERSHAFTS

14 '141 COUNTERSHAFTS MAINSHAfi

(5-32)
Courtesy of Eaton Corporation

REVERSE GEAR SET

Figure 5-33 gives more detailed views of
single and twin countershaft trans-
missions.

Courtesy of Ford Motor Co

INPUT SHAFT

(5-33) TWIN COUNTERSHAFT TRANSMISSION

ENERGIZED SYNCHRCNIZER
IN NO ANO 3RD GEAR

THIRD SPEED GEAR

THRUST RETENTION RING

\mown SPLINES
FOR DRIVE YOKE

LARGE DIAMETER
BEARING RETENTION BOLT

dr STEEL man HARD BRONZE BUSHING IN 2N0 GEAR

...tt NFAVY DUTY
TRUNNION MOUNTED
REVERSE IDLER
GEAR ASSEMBLY
FULL JOURNALS UNDER MO. 3PD AND 4TH GEARS
C2124.A

(5-33) SINGLE COUNTERSHAFT TRANSMISSION

Counesy 01 Ford Motor Co
5:16 POWER TRAINS

3. Location and number of transmissions A transfer case can also be coupled to a

used: main transmission. A transfer case is used
for vehicles with four wheel drive
Large vehicles require multiple speeds. providing power flow to the front drive
and may couple an auxiliary three or four axle and giving a super low gear for off-
speed transmission to the main trans- highway work. The idler or transfer gear
mission. For example. coupling a four lowers the power from the main driveshaft
speed auxiliary to a five speed main trans- to the front shaft. In Figure 5-35 a transfer
mission will give a total of 20 speeds. gear is shown with the case removed.
The main and auxiliary transmission
shown in Figure 5-34 is a multi-
countershaft design which allows both
transmissions to be coupled as one.

(5-34)
COutIOSY Oa Eaton Corporation INPUT SHAFT
SLIDING
REAR ORIvE
AND GEAR LOw
CLUTCH

REAR ORM
OUTPUT SHAFT

---L401--11XER GEAR
IDLER SHAFT

L
FRONT ORWF
LOW

FRONT DRIVE
OUTPUT, SHAFT

C21134.

FRONT DRIVE SLIDING

HIGH CLUTCH Courtesy ol Ford Motor Co.
(5-35)

265
 POWER TRAINS 5:17

POWER SHIFT TRANSMISSIONS the gear ratios of planetary gear sets or

the ratios of spur gears on parallel shafts.
Power shift transmissions are one of the most
important inventions in modern machinery. 3. If a final drive section is used. its purpose
Most heavy duty equipment made today has a is to transfer the power flow down to a
power shift transmission. lower level where it can then travel out to
the front and rear wheel drive. The final
A power shift transmission in a heavy duty drive provides a reduction in some cases.
vehicle performs a lob similar to an automatic However. in others where no reduction is
transmission in an automobile. Like an made. the input final drive gear is on a
automatic transmission, a power shift allows one to one ratio with the output gear.
shifting without releasing an engine clutch.
Unlike automatic transmissions however. 4. The hydraulic control system gives life to
shifts for speeds are not made automatically. the powershift assembly. It uses oil to:
but are made by the operator.
lub:icate and cool all the parts
Power shift transmissions can be grouped into
two general types: (1) planetary gear type and
engage the clutch packs
(2) spur gears on parallel shafts. Regardless drive the turbine in the converter
of the type. power shifts have four major com-
The transmission housing general:y ser-
ponents (Figure 5-36):
ves as the oil reservoir. A converter driven
converter pump picks up oil from the housing and
range gear section
filters it. Then the pump pressurizes the
system. The pressurized oil charges the
final drive section (on some) converter. and circulates throughout the
hydraulic control system transmission. lubricating all the critical
areas. A control valve directs the oil to the
various clutch packs to give the correct
combination of speed and direction
required by the operator. An oil cooler is
an essential part of the hydraulic control
system. Oil from the converter is cir-
culated through the cooler and returned to
the transmission. The cooler prevents the
oil from over-heating and destroying the
assembly.
A planetary powershift is shown in Figure
5-37. and a spur gear powershift in Figure
5-38.
Vro
r
gimionmck,..1-7-
Courtesy of
John Deere Ltd
r,

1. The converter replaces the clutch of the

manual transmission. coupling ti J engine
and transmission together. There are
many variations in the size and torque out- (547)
put of converters. PLANETARY
POWER SHIFT
2. The range gear section provides speed
and direction changes. It uses
hydraulically applied clutch packs to alter

266
5:18 POWER TRAINS

FORWARD

REVERSE

INPUT

(5-38)
SPUR GEAR POWER SHIFT

OW
IGH
UTPUT

Courtesy of Clarke EqurOrnent Co

DRIVING SPIDER
DRIVE LINES
YOKE
The drive line transmits the driving torque DRIVEN YOKE
from the transmission(s) to the drive axle(s). A
drive line may have one drive snatt or it may
have multiple shafts. depending on the size
and drive axle arrangement. Each drive shaft
has a universal joint at either end which TRUNIONS
allows the shaft to hinge. Being able to hinge
makes the shaft flexible and enables it to
transmit power at an angle. A universal joint is (5-39) SIMPLE UNIVERSAL JOINT
a double hinged joint consisting of:
1. two "Y" shaped members called "yokes".
2. a cross shaped member called the
"spider".
3. Four arms on the spider called "trunions".
LOCK
4. bearing caps and needle bearings in- PLATE
stalled on the ends of the trunions. BEARING
CAP
Two illusrations of universal joints are given
in Figures 5-39 and 5-40. The first is a sim-
plified view. The second is more detailed
(note that only one yoke is shown).
LOCK
PLATE

(5-40) BOLTED ENO CAP TYPE U-JOINT

Courtesy of Ford Motor Co

267
 POWER TRAINS 5:19

In a power train the transmission is mounted

rigidly, but the axle housings are moveable.
Thus. splined slip joints are needed to allow
for change in shaft length as the housings
move up and down. In the drive line of the tan-
dem axle truck. shown in Figure 5-41 the inter
transmission shaft. main drive shaft and in-
teraxle drive shaft all have splined slip joints
to allow for length change of the shafts as the
components move in relation to one another.
Cowie Sy of Ford Motor Co
MAIN TRANSMISSION
AUXILiARY TRANSMISSION

INTER-
TRANSMISSION
SHAFT
/ MAIN DRIVE SHAFT REARWARD REAR AXLE

INTERAXLE DRIVE SHAFT

COUPLING
FORWARD
SHAFT REAR AXLE

(5-41)

Long drive shafts will often use a support

bearing caled a center bearing part way
down the shaft length (Figure 5-42). The cen-
ter bearing will be pressed on the drive shaft. As was seen earlier. a basic drive axle con-
A rubber casing is installed over the bearing. sists of a pinion and a ring gear. Power from
and the whole assembly is supported by a the engine is transmitted via the drive shaft to
bracket attached to the frame. the pinion which drives the ring gear. At this
FRAME BRACKET
point in the power train two things are hap-
(5.42) pening:
N4
1. A gear reduction occurs as a smaller gear
is driving a larger gear.
T 2. The flow of power is turned 90° out to the
CENTER BEARING wheels.
Cowesy of Ford Motor Co If the machine went straight and never turned.
the ring and pinion would be all the gears
required at the rear axle. But vehicles do turn
so the outside wheel must travel farther than
the inside and thus must travel faster. To
DRIVE AXLES allow the wheels to travel at different speeds
when turning a differential is required. The
The drive axle. often called the differential. differential has four bevel pinion gears and
does three lobs: two side bevel gears (Figure 5-43). The bevel
pinions and side gears are enclosed in a case
1. Provides a gear reduction. that is bolted to the ring gear. The two side
2 Changes the direction of the power flow. bevel gears are splined to the axle shafts that
go to each wheel. Since it is very difficult to
3. Allows the outside wheel to turn faster understand in words how the differentia;
than the inside wheel when the vehicle gears work. study the gear movement of an
turns a corner. actual differential.

2B8
 5:20 POWER TRAINS

LEFT AXLE SHAFT

RING GEAR

DIFFERENTIAL PINION
ONLY ONE SHOWN
DIFFERENTIAL
CASE DRIVE PINION
SIDE BEVEL
GEAR

RIGHT AXLE
SHAFT

(5-43)

Cowcresy of Ford Motor Co

A problem can occur with differentials when ferential to the wheels is a live axle Live axles
one wheel looses traction and starts spinning. are also referred to as floating axles
Various devices have been made to prevent
this spinning and a differential equipped with Dead axles can be made of either tubular or
one is called a locking differential. These solid steel. Live axles are constructed of solid
locking devices may be mechanical. steel capable of withstanding the twisting
hydraulic. or automatic: the automatic is most stress of the torque that the axle transmits.
common today. Essentially. the locking device One end of a live axle is splined to fit into the
locks out differential action in poor traction differential gears. The other end can be con-
conditions but allows normal action under nected to the wheal in various ways such as a
good ground conditions. bolted flange. a ...plined end :hat fits into 3
flange cap. or a splined end that fits into the
TYPES OF DRIVE AXLES sun gear of a planetary gear set.

There are many variations in drive axle Live Axles

designs. Some variations are:
Two kinds of live axles arc used in
single reduction front mount au.omobiles and trucks today:
double reduction top mount
single speed Standard differential Full-Floatin Axles.
two speed ;ocking differential ti .ns wheels. but doesn't carry the Weight
Axle shafts are divided into two general ..,f the vehicle.
groups. ii Floating Axles,
dead axles turns wheels as we as carrying the
live axles weight of the vehicle:.

A dead axle doesn't move it is stationary Fe:I-Floating Axles

while a wheel turns on it. Examples of dead
axles are a trailer axle and a front wheel spin- Full-floating axles (Figure 5.44) are used in
dle many heavy duty trucks. Each drive wheel and
hub turns on One outer end of the axle housing
A live axle moves. it IS attached to a wheel on a pair of tapered roller bearings. The
and the wheel and axie turn together. The bearings are positioned outside the axle
axle shalt transferring power from the dif housing. In this way the axle housing takes

269
 POWER TRAINS 5:21

the full weight of the vehicle and absorbs all Semi-Foating Axles
stress or end thrust caused by turning. skid-
ding. etc. The axle shaft only transmits the Semi-floating axles (Figure 5-45) fit into the
torque from the engine and is said to float in differential and turn within the axle housing
the axle housing. The most common full- the same way as full-floating axles. However.
floating axle is splined at the differential and there is a critical difference in the two axles.
has a flange at the other end. The flange is With a full-floating axle. the wheel and hub
bolted to the outside of the wheel hub. On turn on the axle housing and the axle shaft
machines with planetary final drives the axle just transmits drive torque. On the other hand.
will be splined at both ends. with a semi-floating axle the wheel and hub
are attached to the outer end of the axle.
Full-Floating Axle Courtesy of John Deere Lid Therefore. the axle shaft supports the
vehicle's weight as well as transmitting drive
DRIVE
WHEEL
WHEEL HUB torque. It must take all the weight and all the
AXLE HOUSING stresses caused by road impact. turning. and
AXLE SHAFT ONLY TAKES FULL WEIGHT skidding.
TURNS WHEEL OF VEHICLE
The outer end of a semi-floating axle is sup-
ported by one bearing that is pressed onto the
axle shaft and fits into'the axle housing. Two
types of bearings are used: tapered roller
bearings or ball bearings. Where tapered
roller bearings are used. an adjustment for
axle shaft end play is provided. The ad-
justment is made with shims or a nut located
at one end of the axle housing. In order to
transmit equally shaft end thrust to the
bearings at both ends of the axle housing. a
thrust bloc or spacer is located between
SLEEVE NUTS
RETAIN BEARING the inner ends of the two axle shafts within
WHEEL HUB SUPPORTED the differential carrier.
BY BEARINGS ON
I 4: AXLE HOUSING
Semi-floating axles are commonly used in
(5-44) FULL-FLOATING AXLE SHAFT automobiles and light trucks. The outer ends
of the shaft may be flanged or tapered as
shown below. When the shaft is tapered. the
wheel hub is keyed to the shaft and locked in
place with a nut.

Beonng
Axle
Shoff
Acliustmg Axle
Shims Sho It

I 7 TAPERED ROLLER BEARINGS AND SHAFT x ':is-4 B -L BEARINGS AND FLANGED SHAFT

Courtesy of John Deere LW

(5-45) SEMI-FLOATING AXLE SHAFTS
TWO TYPES

270
111W....111l.INIIIMM11
5:22 POWER TRAINS

RETARDERS
A retarder (Figure 5.46) supplements the main
braking system of a vehicle. A retarder cannot RETARDER
stop a vehicle by itself. Rather, it assists the VAN
TRANSMISSION W.A. LAr
brakes in stopping the vehicle. From outward
appearance, a retarder looks similar to a
torque converter. In actual fact though, the
retarder performs an opposite function to a
converter. absorbing torque rather than trans-
mitting P.
Hydraulic retarders are mounted in the power
train at one of three locations:
1. In the engine behind the flywheel. 4 IMPELLER
CONVERTER
CONTROL
VALVE HOUSING
2: In the transmission between the converter
and the transmission.
a Within the drive line. (5.46) TRANSMISSION RETARDER
,w!,721 Courtesy of General Motors Corporation
A retarder consists of three bask. oarts: a
housing. rotor. and stator (Figure 5-47).
(5-47) a

In addition, the retarder requires some means "*.

of applying oil under pressure (a load cylin-
der) and a means of cooling the oil (an oil
cooler).
Figure 5-48, is a diagram of an engine retarder
system:
ROTOR
STATOR
(5.48) SCHEMATIC OF ENGINE RETARDER HOUSING Courtesy of Caterpillar Tractor Co.

Courtesy of Caterpillar Tractor Co.

OIL COOLER

oil
system

1
OIL
CONTROL
VALVE

27i
 5,

POWER TRAINS 5:23

In a retarder the housing is the stationary The degree of retarding effect produced by a
component and the rotor is the moving one. retarder is controlled by the operator through
The rotor is driven by the engine. transmission a foot or a hand controlled valve. When using
or drive line. The internal surface of the the retarder. the operator should keep in mind
housing has fins on one or both sides of the that the retarder is only meant to assist the
rotor The rotor may also have fins on one or brakes not to replace them. and that the
both sides, depending on how the housing is engine RPM's should be kept up to provide
made. The rotor runs with a very close sufficient air flow for the retarder cooler.
tolerance to the housing.
GREASE AND OIL
When the retarder is in the unapplied position. I
oil freely circulates within the retarder Before getting into preventive maintenance
housing, causing little or no drag on the rotor on power trains a discussion on grease and
(i.e.. the drive train). When the retarder is ac- oil is necessary.
tivated by applying air pressure to the oil, the
pressurized oil is churned and sheared be- Grease
tween the closely tolerated housing and rotor. Grease consists of an oil of a certain viscosity
causing a strong resistance which slows the range (viscosity is the resistance of a liquid to
rotor and thus the drive train. By resisting flow) combined with a thickening agent such
drive train motion. the retarder helps slow as soap. Additives are included to give
down the vehicle. stronger wear and performance qualities to
Friction in the retarder creates heat that must the grease:
be dissipated. This is done by circulating GREASE = OIL + SOAP + ADDITIVES
through a cooler and back into the retarder
(Figure 5-49). The following additives go into grease (and
into oil):
The source of a retarders oil depends on its
location An engine retarder uses engine oil oxidation. corrosion and rust inhibitors.
and a transmission retarder uses transmission extreme pressure and anti-score agents
oil. A drive line retarder. not having an im-
mediate source of oil. has its own oil supply. Types of Grease
Some common types of grease are:

AIR CONTROL vAlvE

1. lithium soap grease -- multi-purpose
2. calcium cr lime soap grease cup
(549) grease
SCRAPER BRAKE
CONNECTOR
4 3 aluminum soap grease excellent
chassis grease

2/ 4. sodium or soda soap grease

bearings
wheel

5. barium soap grease not common

t special application
Out COOLER
Each grease has qUalitites that allow It to do a
certain job. Note that some greases are in-
m oil compatible and should never be mixed
0 AIR
together. All manufacturers specify what
grease must be used on different parts of their
LOAD CYLINDER
equipment. Whenever a part is to be greased.
always refer to the service manual for the
BREATHER LINE correct type of grease to be used. Here is an
example from a service manual for a tractor-
--RETARDER scraper stating what kind of grease to use:
BRAKE MAIN VALVE RETARDER TEMPERATURE INDICATOR lINE

COHOOSY 0: Caierodiar Tractor Co

2 72
5:24 POWER TRANS

LUBRICATING GREASE CARE OF LUBRICANTS

Use Multipurpose-type Grease (MPGM) Lubricating oils and greases are highly
which contains 3 - 5% molybdenum refined products. made to meet rigid
disulfide conforming to MIL-M-7866. specifications. Lubricants must be correctly
and a suitable corrosion inhibitor NIG,
No 2 Grade is suitable for most tem- stored. handled and dispensed if they are to
peratures Use NLGI No. 1 or No 0 do the job they are designed for. Clean. un-
Grade for extremely low temperatures contaminated lubricant is essential to
properly service or assemble mechanical
Gear Oils equipment.
Oils have the same additives as grease GOOD PRACTICES IN HANDLING,
(oxidation. corrosion. rust inhibitors; extreme DISPENSING AND STORING LUBRICANTS
pressure and anti-score agents) but also in-
clude the following. friction modifiers. pour 1. Always use clean containers for dispen-
point depressants. foam depressants. sing lubricants.
Oils are classified according to their viscosity 2 Rinse and cover containers when not in
and their performance characteristics. The use to prevent dirt and moisture con-
Society of Automotive Engineers (S.A.E.) tamination. e.g.. wheel bearing grease
classifies oils by viscosity using numbers like: containers.
75W 3. When adding oil or changing filters clean
80W the higher the number the the oil cap or cover before removing it.
85W greater the oil's viscosity (the
thicker the oil) 4. Always clean grease fittings before ap-
90W
plying the grease gun.
140W
5. Keep lids on barrels and buckets when not
The American Petroleum Institute (API) in use.
classifies oil by performance. oy the type of
work the oil is suited for. API uses a num- 6. Wnenever possible store lubricants in a
bering system for gear oils as follows' clean. closed room or area and at a fairly
GL 1 straight mineral oil even temperature. Over long periods of
straight mineral oil with time extreme temperature changes can
GL 2
antiear additives alter the lubricants' characteristics.
GL s mild extreme pressure 7. If lubricants are stored outside. lay the
additives barrels on In& side or tilt them slightly.
GL 4 All have extreme I........:.ure ad- ...sitioning the bungs at the sides. Be
GL 5 ditives to handle increased sure the bungs are kept tight. This prac-
GL 6 loading. but each has different tice will prevent water from entoring the
specifications to meet manuiao- lubricant through expansion and con-
turer's requirements. traction of the barrels. If the barrels are
As with grease. manufacturers specify the not under cover. cover them with a tar-
type of oil that must be used in a given part or paulin whdn thy; are not in use Always
system. When lopping up or changing oil clean the top of a barrel before opening it
always check the service manual for the
correct type and amount of oil to use. For
example. the manufacturer will recommend.
that you use an oil equivalent to GL-5-SAE 90.
Each oil company will have a product name
for its oil, but it will also give the GL and SAE
rating.

273
 POWER TRAINS 5:25

CAUSE ie,/ //1/0V);/,51/ AU!

IRS

//ie/ z RAIN %/1.;/,../

//X./. z.//././1 wA TER

4/
/Am SPAC(
7-7 w.

PORERFUL
remota
CREATED

/
AS SPACE
REDUCED OIL AND AIR IN
BARREL EXPAND
0CLEAA OlLy WHEN WARM.
SOME OF AIR
/DELIVERED/ ABOVE OIL
ESCAPES.

1 4 A
WATER

PREVENTION

I. KEEP BUNGS DRAWN TIGHT,

USE WOODEN MALLET TO MAKE SURE.
2. STORE BARRELS INSIDE WHENEVER POSSIBLE.
(WARM STORAGE IN WINTER PREFERABLE) OR
3. AT LEAST UNDER COVER.
4. IF STORED JUTSIDE, LAY BARRELS ON THEIR SIDES.
5. IF BARRELS CANNOT BE LAID ON THEIR SIDES,
TILT THEN SLIGHTLY AS SHOWN BELOW.

WATER AROUND BUNG

WAY SE DRAWN INTO
ND WATER AROUND BUNG
BARREL.
TO BE DRAWN
INTO BARREL

VI 4.

(5 -50) STORAGE PRACTICES WHICH PREVENT

CONTAMINATION OF OIL
Courtesy of John Deere LW

274
5:26 POWER TRAMS

QUESTIONS POWER TRAINS 11. Give two advantages of a jaw clutch.

1. Match each component below with the 12. A torque converter can multiply the
job it performs listed at the right. torque it receives from the engine. True
or False?
(a) clutch 1. equalizes power
for turning 13. A torque converter consists of three main
1.insmission 2. connects and dis-
parts: a pump. a turbine and a _.
(b)
connects power 14. Briefly explain the advantage of a multi-
countershaft transmission over that of a
(c) differential 3. selects speeds and single countershaft.
direction
15. What are the two basic types of power
2. !1st the three basic methods of trans- shift transmissions?
mitting power and give an example of
each. 16. Shifts for speed and direction in a power
shaft transmission are made:
3. When a small gear drives a large gear
there Is a speed decrease and a torque (a) automatically
increase. True or False?
(c) manually
4. Calculate the gear ratio when a 13 tooth (c) semi-manually
gear drives a 52 tooth gear. If the small
(d) semi-automatically
gear travels at 600v RPM'S. whSt is the
speed of the larger gear? 17. What is the reason for having an
auxiliary transmission?
5. What IS the advantage of a helical gear
over a straight spur gear? 18. What is the purposrl of the splined slip
iornt on a drive shaft?
6. A planetary gear set consists of a:
19. What three jobs does the irive axle do?
(a) ring gear. one planet pinion and a
sun gear 20. The function of a locking differential is
(b) ring gear. a drive and a sun gear to:
(c) ring gear. carrier. and internal gear (a) sped the wheels up in poor traction
(d) ring gear. carrier and sun gear
conditions
(b) stop one wheel and allow the other
7. In a planetary gear set where the ring to drive in poor traction conditions
pear is held and the sun gear is powered.
there is a. (c) slop both wheels in poor traction
conditions
(a) speed increaFe to the carrier in the (d) lock Out differential action in poor
same direction traction conditions
(b) speed decrease to the carrier in the
same direction 21. Two general classifications of axle
shafts are:
(c) speed decrease to the carrier in the
opposite direction (a) long and short
(d) speed decrease and torque increase (b) dead and live
to the carrier in the same direction (c) small and large
(e) both (b) and (d) are right (d) left and right
8. When two gears are in mesh. what does 22. What is the difference between a live
the term backlash refer to? axle and a dead axle?
9. In an engine clutch. what is the ad- 23. How doe? a retarder differ from a torque
vantage of adding a second friction disc converter? Can a retarder be used to
and an intermediate pressure plate? stop k.: vehicle?
10. Why is the friction lining on clutch packs
usually different than the fritaion 1:ning
on an engine clutch?

275
 POWER TRAINS 5:27

PREVENTIVE MAINTENANCE SERVICE ches can go thousands of miles and not need
OF POWER TRAINS adjustment. Under very stressful conditions
#he clutch may need adjusting (Jai. Another
Preventive maintenance service of Power factor affecting clutch adjustments is the
Trains on a daily basis should consist of a operator. Some drivers or operators are hard
thorough visual check of all the drive com- on clutches and their clutches will need more
ponents from the engine out. Look for: frequent adjustment.
1. Loose parts Power train components Clutch adjustment vane, 'h the type of
involve many moving parts that carry clutch. A push clutch (i.e.. the release bearing
heavy torques and stresses. These parts is pushed to disengage) is used on smaller
can work loose Check especially the vehicles. This type of clutch has an adjusting
areas where power is transmitted from a mechanism such as a threaded rod located
stationary part to a moving one. i.e.. trans- externally on the linkage. Larger vehicles
mission and drive shaft. generally use a pull clutch (the release
2 Oil leaks There are a number of oil bearing is pulled to disengage) which is ad-
compartments. and in some cases con- justed internally or inside at the pressure
necting hoses, in power trains. Under plate Clutch brakes are used in conjunction
stress and heat, leaks will develop. Make with pull clutches. A clutch brake slows down
any minor repairs. and report major ones. the transmission input shaft on un-
Oil level checks will be made on a synchronized transmissions to aid in shifting.
scheduled basis. Clutch brakes are applied with the clutch
3 Faulty adjustment To compensate for pedal when the pedal is approximately one
running wear. adjustments need to be inch from the floor boards. Adjustment to
made on belts, chains. clutches. Adjusting clutch brakes are made externally on the
clutches will probably be the most com- linkage.
mon adjustment a first year apprentice will Clutch Clearance
do. and is detailed below.
Clutch clearance is the amount of clearance
CLUTCH A:.aJUSIMENT between the reloase bearing and the release
levers. point #1 in Figure 5-51 showing a sim-
A major factor in clutch adjustment is working plified view of a push clutch.
conditions. Under ordinary conditions clut-
PR ESSURE PLATE RELEASE LEVER
(or Release Fingers)

SPRING

FREE CLEARANCE
BEARING RETURN
RELEASE
EASE
SPRING

RELEASE BEARING RELEASE

(5-51) SLEEVE
PUSH CLUTCH -- ENGAGED POSITION
RELEASE YOKE
ATTACHED HERE Courtesy of lipe.Floilway C000rairon
5:28 POWER TRAINS

The correct clearance prevents the release 3. The proper clutch pedal free travel is ap-
bearing from riding constantly against the proximately 1t/2". The gradual reduction
release fingers of the pressure plate. As wear from this amount is a normal condition
occurs on the disc lacir.gs. the release levers caused by facing wear.
move towards the release bearing taking up
the clearance If the movement of the release 4. If inspection indicates clutch pedal free
levers is not compensated for. the pressure travel is less than V2". immediate ad-
against the release bearings will cause the justment should be made to restore the
clutch to slic. under load proper 11/2" travel. This 11/2" of free travel
normally results in Vs" clearance between
The clutch adjustment for this push clutch the release bearing and the release
would be a threaded rod located outside the levers. Figure 5-53 shows a correctly ad-
clutch housing. Adjusting the threaded rod justed push clutch.
would pull the release bearing back on the
release sleeve making a gap (ttl) between
the bearing and the release levers of the
pressure plate. This gap has to be wide
enough to let the release bearing be free of
the release levers when the clutch is fully
A
engaged. but narrow enough to allcw the PEDAL FREE TRAVEL

release bearing to fully disengage the

pressure plate when the clutch pedal is com- FLOORBOARD CLEARANCE
pletely depressed.
Correct clearance between the release
bearing and release levers will usually give
approximately 1 1/2" of free travel at the pedal.
Therefore. a check of clutch pedal free travel
will tell if the clutch needs adjustment.
( \1\ 11111010l1111AJ

1 FREE PLAY
Below is a typical section from a service
manual on clutch adjustment. The clutch
referred to is a basic push clutch. (5-53)
Clutch Pedal Adjustment
Courtesy of lipe.R011way Corporation
1. The clutch must be kept in proper ad-
justment by frequent inspection of clutch
free travel, the first easy movement of the Below is a typical adjustment procedure for a
clutch pedal. puti clutch equipped with a clutch brake. Ad-
2. Check the clutch pedal free travel by hand justment to the clutch is made internally: the
(Figure 5-52) and be sure that the free release bearing assembly is reached by
travel IS a result of actual release bearing removing a cover on I"' nderside of the
clearance and is not caused by worn flywheel. Note: The clutcn or.ke may also
linkage or faulty hydraulic cylinde's, have to be adjusted (it is adjusted externally).
depending on what has previously been done
to it.

Clutch Adjustment
111PIPT"-- 1. Unlock sleeve locknut "D" (Figure 5.64).
., 2. Turn slotted spanner adjusting nut "E" for
proper clearance.
4.'1:F1.3rWW:4"P7.- 7/16" for 14"-2PT
1/2" for 1512"-212T
gtir 3. Lock sleeve locknut "D"

(5-52) CHECKING CLUTCH PEDAL "Ffti.E TRAVEL'

Courtesy of licre.R011way Corporation
277
 - 1410 Alw.-

POWER TRAINS 5:29

(5-54) SECTIONAL VIEW OF RELEASE BEARING

Rae* ermurriouilito C FRONT -- CLUTCH IN 06111IGAGLD POMPON APPLYING CIVICS' ORAN(

ARELEASE LEVER SPIDER BRAKE DISC.

Paha* ;
Iapagelatchalsa** r.

Fa PON
NM's* IracH

oc,

0SLEEVE LOCHNUT
f--CorttoOrsass
ESLOTIE0 ADJUSTING NUT Ito's. loRa

Trachoma
tadFULTIC FOR sr4 Elsonce WP
RELEASE TRAVEL
Strong tomoa
Courtesy of Ljoe-Rollway Corporation

cooler
Figure 5-55 shows a properly adjusted pull aelmol RN.
IRS Osinaglarmiecit
IracaP

clutch in engaged and disengaged positions. cactactaltbArlolloas

MEEK IN INGAGLO POSITION Amp PROPERLY AMSTED

(5-55)
Courtesy 01 Lioe.Rollway Corporation

Oa hat otala
lea
wdl may rascal**
NalsocattosworrMw
Lubricating Release Bearings
Lubrication of the release bearing is very im-
portant on large equipment. (Release
bearings for clutches in smaller vehicles are
prene.;ked). An example of lubrication in-
structions are shown below:
Milton Vaa calico erattv I. The release bearing housing has not been
pre-packed with grease! it must be
lahmessa lubricated when the clutch is installed in
Front IIMMS WP
the vehicle or Premature failure will occur.
haat Man Pad
Yea Cisaraset-ka
2. Only high temperature greases should be
a-rr-o-itsltaes tarsi
ca far Ta
Vs far TO .21, used. Chassis lube or all purpose
Ira for IS LP lubricants are not recommended.
'SRI Chsten Dna/ tr pd rood ab sperm:clad taitmishaa1-0*
Musa cm atust IM Nast 0115105 trautoat 4 be artariallat,
riternins PooSsolcaCaP.
3. Add lubricant at each chassis lubrication
period or more often if service is extreme.
(5-55) Only a small amount is required.
Courtesy of LopeRoilway Corporation 4. To assure adequate distribution of the
grease throughout the bearing, the engine
fshould he running while grease is being
adried.

278
 ...---.r.-.
5:30 POWER TRAINS

SCHEDULED MAINTENANCE ON engine be running when making the final

POWER TRAINS oil level check.
Scheduled maintenance on power trains LUBRICATION SERVICE EXAMPLES
specifically refers to checking the oil levels
and changing the oil. At the same time that Following are examples of power train
scheduled maintenance is carried out, lubrication service taken from Service
though. check for loose parts, oil leaks. and Manuals for three different machines:
make necessary running adjustments.
1. Manual transmission for an on or off-
Note that the manufacturers time schedule highway truck.
for checking and changing oil generally ap-
plies when the machine is working under nor- 2. Crawler Tractor with a power shift trans-
mal conditions. If a machine is working under mission.
severe conditions. the oil should be checked 3. Wheel loader with a power shift trans-
and changed more frequently than stated in mission and standard drive axles.
the service manual.
Note the different style in which each of these
The procedures to change the oil on a manual manufacturers present their lubrication in-
transmission. power shift transmission, drive formation.
axle or final drive are much the same.
although the locations of the drain. the fill
plug and level plug. filters and screens differ
from machine to machine. See service
manuals for specific instructions.
Some general points when changing oil are:
1. Before removing a drain plug be sure you
know the capacity of the housing and
have a drain bucket large enough to hold
all the oil.
2. Have the component up to operating tem-
perature before draining.
3. When removing the drain plug be careful
of the hot oil.
4. If the component is equipped with a
filter(s) remove it and clean the housings.
Install a new filter. Take a minute to cut
the old filter apart and see if it has trapped
any metal chips.
5. Clean all accumulated material from
magnetic drain plugs.
6. If the component is equipped with a sump
and screen. remove and clean them.
7. Some manufacturers recommend flushing
housings with flushing oil or with
kerosene. Flush only if recommended.
8. Be sure to refill the housing with the
correct (1) type and (2) amount of oil. Do
not overfill.
9. On oower shift machines run the engine to
cr ge the converter. Check the filters for
let....s and recheck the oil level. Note that
some transmiesinns require that the

279
 POWER TRAINS 5:31

LUBRICATION FOR ON AND OFF HIGHWAY MANUAL TRANSMISSIONS

(Courtesy of Eaton Corporation)
LUBRICATION
RECOMMENDED LUBRICANTS
ONHIGHWAY VSNICUS

Heavy.duty engine oil. Make sure to specify heavrdoty

Type

Heavy Duty Engine Oil

,1,-
Grade

SAE 30
Temperature

Above 4. 10.
type meeting MILL2104B specificaiions.
MIL11210413 SA E 30 below + 10F.

Mineral gear oil inhibited against rust. oxidation and Mineral Gear Oil SAE90 Above + 107.
foaming. Il and 0 Type SAE 80 Below tor.
Mild E.P. Oil, except SAE90 Above + 10F.
Extreme preSTure oils under some condilions might form
Sulforchlorinelead type SAE 80 Below + 10.F.
carbon deposits on gears, shafts, bearings and sYnchro Mil210g
niter discs, and may also glaze friction surfaces of
synchronize, discs conditions which will result in OFFHIGHWAY AND MINING EQUIPMENT
transmission matfanction and premature failure. It is
Heavy Duty Engine Oil SAE 30 Above + 10T.
suggested that if these conditions exist, and E.P. oil is MILL2104B SAE30 Below + 10F.
being used, a change should be made to mineral oil or
Special Recommendation For extreme told weather
hcavy-duiy engine oil as recommended.
where temperature is consistently below O'F.

Heavy Duty Engine Oil SAE 20W Below 0.

MRL2104B

(5-56) Courtesy of Eaton Corporation

These TRANSMISSIONS are designed so that

the internal parts operate in a bath of oil cir-
culated by the motion of gears and shafts.
Grey iron parts have built-in channels where
needed. to help lubricate bearings and shafts.
Thus, all parts will be amply lubricated if
these procedures are closely followed:
1. Maintain oil level. Inspect regularly.
2. Change oil regularly.
3. Use the correct grade and type of oil. - .,,I, -,
e-it):-.Iit
4. Buy from a reputable dealer.
To keep the gear oil clean between oil
changes use the Fuller Transmission Gear Oil
Filter which can be attached to the right-side
power take-off opening. This assembly in-
cludes a replaceable filter element that TRANSMISSION GEAR
removes the accumulation of metallic par- (5-57) OIL FILTER
ticles, road dirt and grit deposited in the Courtesy of Eaton Corporation
lubricant.

280
5:32 POWER TRAINS

Draining Oil Inspection

To drain the transmission remove the drain Gear oil is to be kept even with the level of the
Plug at bottom of case. Drain oil when trans- filler opening at all times. Check at the
mission is warm. After the transmission has following intervals:
been drained. and before it is refilled. the
case should be thoroughly flushed with a Highway Service 1 000 mites
clean flushing oil or kerosene. Do not use Off-highway Service 40 hours
flushing compound if unit is equipped with
side or front mounted pressure lubrication Gear Oil Change
pumps unless pump is removed and opening
covered with plate. Clean the drain plug Change the gear oil on all new equipment af-
before reinstalling. ter the first 3000 to 5000 miles ion - highway).
or first 40 hours (off-highway); thereafter.
Refiliing make oil changes as follows:
Before removing the filler plug on left side of Highway Service 25.000 miles
case, all dirt should be removed from the area
of the case adjacent to the tiller opening. Fill Off-highway Service
the transmission to the level of the filler Logging and associated
opening. metering approximately 25 pints to operations 1 000 miles
as pints of gear oil into the transmission. The Dirt moving, mining
exact amount will depend upon the inclination and associated
of the transmission and model designation. In operations 250 to 500 hours.
every instance. fill to the level of the filler as indicated by operation and con-
opening. tamination of lubricant.
Do not overfill. Overfilling will cause oil to be
forced out of the case through the mainshaft Special Recommendation
openings. The above oil inspection and change periods
are based on the average use and operating
Adding Oil conditions for the applications listed. It is
It is fere. mended that types and brands of ail recommended that the individual owner make
not be intermixed because of possible in- a periodic lab analysis of the lubricant to
compatibility. determine contamination based on the in-
citvidual's own operating conditions. After this
Operating Temperature nas been determined, the individual owner
can then set his own inspection and oil
It is imperative that the operating temperature change periods.
of the transmission does no' excs.ed 250 F.
Clutch Release Bearing
Extensive Operation at temperatures ex-
ceeding 25fr F will result in rap:d breakdown Follow vehicle manufacturer's chassis
of the oil and shorten transmission life. lubrication recommendations.
Transmissions used in stationary equipment. Oil Filter
or in vehicles operating at slow road speeds.
may have to be equipped with extornai If so equipped. replace filter element at each
coolers so that the 250 F temperature is not oil cnange: clean filter element housing.
exceeded.
Courtesy of Eaton Corporation

2,91
 POWER TRAINS 5:33

LUBRICATION AND MAINTENANCE CHECKS FOR A CRAWLER DOZER (CAT 06)

WITH A POWER SHIFT TRANSMISSION
(Courtesy of Caterpillar Tractor Co.)

Lubricating Grease
Use Multipurpose-type Grease, NLGI No. 2
Grade is suitable for most temperatures. Use
NLGI No. 0 or No. 1 Grade for extremely low
temperatures. Wipe all fittings, caps and
plugs before servicing.

Lubricating Oils
Superior Lubricants (Series 3): API Engine
Service Classification CD: Additive type oils
that meet rigid, high quality standards and are
certified for use in Caterpillar diesel engines.
Must contain zinc dithiophosphate when used
in a hydraulic system.
NIL-L-2104A Oil. API Engine Service
Classification CA; or MIL-L-2104B Oil, API
Engine Service Classification CC: Additive
type oils, but milder than Superior Lubricants
(Series 3).
Multipurpose-type Gear Lubricant (MIL-L-
2105B): AN Gear Lubricant Designation, GL-
5: Used in gear compartments where gear
loads and speeds are factors. In extremely
cold temperatures consult your oil supplier for
special Arctic Lubricants.
Your oil supplier is familiar with the oils
meeting those requirements.

RECOMMENDED LUBRICANT AT VARIOUS STARTING TEMPERATURES

COMPARTMENT OR I ABOVE 32°F 1 32°F Bs 10 °F I-12°C fe -23°C) 1 BELOW -WP 1

SYSTEM (0°C) I WC Be -12°C) [ 10°P to 16°P I I-23°C)

SUPERIOR LUBRICANTS (SERIES 3) ONLY
Dieml engine crankcase SAE 30 SAE tOW°' SAE IOW° SAE IOW°
Transmission, bevel gear and
steering clutches SAE 30 SA2 30 ME IOW SAE IOW
Cable control gear case SAE 30 SAE 30 SAE IOW SAE IOW
SUPERIOR LUBRICANTS (SERIES 3), MI1421041
Hydraulic system SAE IOW SAE IOW SAE I OW°' SAG IOW"'
MULTIPURPOSTYPE GEAR LUBRICANT M114021051
Final drives I SAE 14061 I SAE 90 SAE 90 # SEE NOTE°

"SAE 10W ea may be used in The diesel engine even if daytime ambient f*roperthwe rims to 70.1 (WC), Below 10F (23C)it
may be necessary to warm the enghe oil so tha engine an be stinted and the oil will circulate freely.
140,041in industriel4ype Hydraulic Oils may be used at arkornely low temperatures. Consult your oil supplier for oil moiling this re.
gvirement.
"SAG 140 musr not be used when the ambient ton:potato* k below 32F (VC).
"Consult your oil supplier for special Amtic Lubricants.

(5-58) Courtesy of Caterpillar Tractor Co

232
5:34 POWER TRAINS

IMM=.11.
ITEM
i SERVICE

EVERY 10 SERV!!"5. HOURS OR DAILY

Transmission. bevel gear and Check oil level. Change oil if it
steering clutch cor.partment becomes extremely dark in color
and has started to thicken.

EVERY 250 SERVICE HOURS OR MONTHLY

Transmission. bevel gear and Change filter element
steering clutch compartment wash magnetic strahier
Steering clutch brakes Check adjust if necessary

EVERY 1000 SERVICE liOURS OR 6 MONTHS

Transmission. bevel gear and Change oil and breather wash
steering clutch compartment suction screen
Universal joint and clutch brake Lubricate three fittings

WHEN REWIRED
Clutches Require periodic maintenance that
cannot be given a definite service
hour interval. Maintenance information
is given in the service manual.

KEY TO LUBRICANT
S3 Superior Lubricants (Series 3) only.
HYD Superior Lubricants (Series 3) containing zinc dithiophosphate. MIL-L-2104A. M`L-L-
21048 or approved industrial-type Hydraulic Oil.
MPG Multipurpose-type Grease
MPL Multipurpose-type Lubricant

283
M
 1.1.111.1.1!1IN

POWER TRAINS 5:35

LUBRICATION AND MAINTENANCE CHECKS ON A WHEEL LOADER WITH A

POWER SHIFT TRANSMISSION AND STANDARD DRIVE AXLES
(Courtesy of Clerk Equipment Co.)

HOURLY LUBRICATION & MAINTENANCE SCHEDULE

Warning: Except when specified, lower all attachments to the ground, apply the parking brake.
shut down the engine, remove the ignition key, turn the disconnect switch to the "OFF" position,
block the wheels. engage the articulation lock and tie a red warning flag on the canopy upright;
when servicing the ma'.:hine.

TEXT HOUR
SYS1EM OPERATION LOCATION INTERVALS

,§

Torque Check Fluid Level Daily. at the Transmission

Converter
Transmission Clean Torque Conv,rter & Transmission Eire ethers

Replace the Filter Element

Check System for Leaks

ehnck Converter Out Pressure

ChecK & Adjust Transmission Shift Linkage

Drain and Refill Transmission. Converter.

Winch, Hydraulic System

Check Transmission Clutch Operating Pressures

Axle Prop Check Tire Pressures and Castings

Shafts
ano Tighter. WI:eel Nuts & Inspect Rims
Wheels
Check Fluid Level of Differential & Planetary

Clean Breathers

Dram and Refill Differential & Planetary

Check for and Repair Drive Line Noises

1

Courtesy of Clarke Equipment Co

284
5:36 POWER TRAINS

HOURS KEY
TEXT
DRIVE LINE LUBRICATION LOCATION

80 i7
50 012 §2

27* I Universal Joints 9 LBG

28 I Split Joints 3 LBG

29 Transmission. Converter and Winch DX

30 Differential Check & Fill Pug (2) EPGL

1 31 Differential Drain Plug EPGL

32 Planetary Drain & Fill Plug EPGL

33 Planetary Check Plug EPGL

. _
34 Pillow Block Grease Line LBG
t_

I35 I Pillow Block Seal Area (Repack)

VI I I ill DA I

* Locate these numbers on the diagram on the nest page.

LUBE'r:AllON KEY

Lithium Base MultiPurpose Grease

LBG 0`F. and above -- Grade 2 _
Below 0°F. Grade 0

EPGL Extreme Pressure Gear Lube (* * SCL Type) SAE 75. SAE 90. or H090

Ambient Temp. Range [Lubricant to be used

SAE Grade API Class Military Spec.

1) 10W +MS MILL2104A. Supp. 1

DM or New MILL2104B
DX Above 0°F.
2)
Dexron Automatic Transmission Fluid

Below 0° Dexron Automatic Transmission Fluid

+ Sequence Tested

BA Heavy Duty Brake Fluid SAE J 1703 or equivalent

DA Shell Darina ""AX" Grease Or Equivalent

* *"SCL" Signifies Sulfo-Chloro-Lead type. Factory fill i' Tiede with SCL type tube and it is recommended
that the same type be used when adding or refillin.
Courtesy of Clarke Moment Co

285
 POWER TRAINS 5:37

DRIVE LINE LUBRICATION POINTS

(5-59)

Courtesy of Clarke Equipment Co.

286
5:38 POWER TRAINS

SCHEDULED MAINTENANCE ON the differential must be disassembled. as well.

RETARDERS to get the shaft out. The axle shaft and
bearing can then be pulled from the housing
In most cases hydraulic retarders are in- with a slide hammer puller. The bearing has to
corporated with either the engine oil tube be pulled from the axle shaft (and installed)
system or the transmission oil system. so that with a hydraulic press.
when the oil is changed in either of these
components the retarder's oil is also changed.
However, some retarders have their own sup-
ply of oil which should be serviced at recom-
mended intervals.
Caution: On retarders wtih a self-contained
oil supply be sure that the load
control is in the re.eased position
before attempting to remove the
reservoir cover. Failing to put the
control in release could result in a
shower of oil, hot oil if the machine
has just been working.

REMOVING AXLE SHAFTS

Although you will not likely be involved with
power train repairs at this level of training.
you will probably have to remove axle shafts.
For example. packing wheel bearings or
removing wheels to do brake work requires
removal of the axle shafts.
Removing a flange design full floating axle is
a routine job that can be done without raising
the vehicle. Remove the flange retaining bolts
or nuts. The flange now has to be freed from
the hub and lifted out by hand. Two quick
methods of freeing the flange are:
1. Prying it loose with a screwdriver or
2. Striking the center of the flange one or
two good blows. If the axle flange still
resists. locate two tapped holes 180.1 apart
(found on most axle flanges) that have no
corresponding holes in the hubs. Thread
two bolts into these holes with even
pressure on each and the two bolts will
push the flange free of the hub.
Whenever an axle shaft is removed always
check it carefully for worn splines and signs
of twisting. It is much better to replace a faulty
axle while it's out than to have the axle break
down shortly after its return to service.
A semi - floating axle is more difficult to
remove. The vehicle has to be raised because
the axle shaft not only supplies the torque but
also supports the vehicle's weight. Remove
the wheel and brake drum to gain access to
the bearing retainers. In some cases part of
 POWER TRAINS 5:39

QUESTIONS POWER TRAIN

MAINTENANCE
1. What should a P.M. visual check of the
power train include?
2. Clutch adjustment on a vehicle after a
number of hours sea/ice is necessary to:
(a) make it release easier
(b) compensate for clutch disc facing
wear.
(c) smooth out clutch action.
(d) make it release faster.
3. Before taking out a full floating axle, you
first have to jack up the frame. True or
False?
4. Briefly what should a scheduled main-
tenance of a power train include?
5. When servicing a power train component
how do you k now what type o' iyease or
oil it uses?
6. Referring to the Lubrication Instruction
for the Clarke Wheel loader. what type of
oil does the differential use?
7. All retarders are self-contained hydraulic
systems. True or False?
8. A properly adjusted clutch should have
approximately inches
of free pedal travel.

288
5:40 = POWER TRAINS

ANSWERS - POWER TRAINS 19. Provides a gear reduction. Changes the

direction of the power flow. Allows one
1. (a) 2 (b) 3 (c) 1 wheel to turn faster than the other when
2. 1. friction - clutch - turning a corner.
2. gears - transmission 20. (d) Lock out differential action in poor
3. fluids - torque converter traction conditions.

3. True 21. (b) dead and live.

4. Ratio is 4:1. Since the small gear travels 22. A live axle is attached to the wheel and
four times faster. the speed of the larger turns with it. A dead axle is stationary
is 6000 = 1500 RPM. and the wheel turns on it.
4 23. A retarder absorbs torque whereas a
5. A helical gear is stronger and runs converter transmits torque. A retarder
quieter than a straight spur gear. will not stop a vehicle. it only assists the
6. (d) ring gear. carrier and sun gear. brakes in doing so.

7. (e) both (b) and (d) are right.

8. The clearance between the two gear
teeth at the pitch diameters.
9. More friction surface is obtained within
the same diameter making a stronger
clutch.
10. Clutch packs run wet and need a lining
that won't be harmed by the oil. Most
engine clutches run dry. Oil will con-
taminate dry clutch facings causing the
clutch to slip.
11. 1. cheap to make
2. positive (i.e.. no slippage) once
engaged
12. True
13. ... stator.
14. Torque is divided over two or more shafts
reducing loading on the gears, shafts
and bearings. Therefore. the overall size
and weight of the transmission can be
reduced.
15. 1. planetary gear
2. spur gear on parallel shafts
16. (b) manually
17. An auxiliary transmission increases the
number of speed-torque ratios that the
vehicle can travel at.
18. To allow the drive shaft to change length
as the axle housings move up and down
with respect to the frame.

289
 POWER TRAINS 5:41

ANSWERS POWER TRAIN MAINTENANCE

I. Check for loose parts. oil leaks, and in
correct adjustments.
2. (b) Compensate for clutch disc facing
wear.
3: False
4. 1. Checking oil levels or changing the
oil.
2. Checking for loose parts. oil leaks
and running adjustments.
5. Look it up in the service manual.
6. Extreme Pressure Gear Lube: SAE 75,
SAE 90.
7. False.
13. ... 11/2 inches ... .

290
5:42 POWER TRAINS

TASKS POWER TRAINS DRIVE AXLE

CLUTCH AND CLUTCH BRAKE ROUTINE MAINTENANCE CHECK

(If equipped) 1. Check and tighten any loose drive axle
mounting bolts and components.
ROUTINE MAINTENANCE CHECK
2. Check for oil leaks and make necessary
1. On a truck or tractor truck check and ad- minor repairs.
just the clutch clearance (and clutch
brake if equipped) to manufacturers SCHEDULED MAINTENANCE
specifications. using the correct tools and
procedures outlined in the service 1. Drain the oil. check and clean magnetic
manual. plug. and change the filter (if equipped).
Refill the drive axle with the correct type
MANUAL TRANSMISSION and amount of oil.
ROUTINE MAINTENANCE CHECK 2. Check to ensure there are no oil leaks.
1. Check for and tighten any loose trans- HYDRAULIC RETARDER
mission bolts or components.
ROUTINE MAINTENANCE CHECKS
SCHEDULED MAINTENANCE
1. Check for and tighten any loose retarder
1. Drain the transmission oil. check and bolts and components.
clean magnetic plugs, change the filter (if
equipped) and refill with correct type and 2. Check for oil leaks and make necessary
amount of lubricant (see service manual). minor repairs.

2. Check to ensure there are no leaks. 3. Inspect the reservoir. cooler. retarder and
related hoses for leaks or damage and
POWER SHIFT TRANSMISSION report to a journeyman if a suspected
AND TORQUE CONVERTER problem or an unsafe condition exists.

ROUTINE MAINTENANCE CHECK 4. With the control valve in released position

to prevent a shower of hot oil, check the
1. Check for and tighten any loose trans- oil level and fill it low.
mission bolts or components.
2. Check for oil leaks and make any
necessary minor repairs.

SCHEDULED MAINTENANCE
1. Drain the oil. remove and clean the filter
housing' and install a new filter. Refill the
transmission with the correct type and
amount of lubricant (see service manual).
2. Start the engine and ensure there are no
oil leaks.

DRIVE LINE
ROUTINE MAINTENANCE CHECK
1. On a truck Or tractor truck check and
tighten any loose dr ee line bolts or com-
ponents. Also check the drive line for
wear at the universal joints. splines.
steady bearings and mountings. Report
any suspected unsafe operating con-
ditions to a journeyman.

291
 1
BLOCK

O
Frames, Suspension,
Running Gear and
Working Attachments

292
 BEARINGS AND SEALS 6:1

ANTIFRICTION BEARINGS

PURPOSE OF ANTIFRICTION BEARINGS

Friction is the force or resistance generated
when two objects are moved against one
another. Since friction causes heat and wear.
and thus damage. to surfaces in contact. ways
must be found to reduce it. On a machine.
anti-friction bearings are used to reduce fric-
tion between a shaft. wheel or gear that turns
within a support. The bearings do this by
providing 4 rolling contact for the surfaces.
Lubncatior. further reduces the friction.
Anti-friction bearings perform the following
functions'
allow parts in contact to move more
easily
support a moving part and hold it in
perfect alignment.
reduce the wear between moving parts
provide a replaceable wear surface. It
is more economical to replace a
bearing than to replace a shaft or a
gear.

Figure 6-1 shows where bearings would be

found in a typical tandem truck.

TRUCK
REAR
REAR
WHEEL AXLES

FULL
FLOATING

001.181REDOCTION
AXLE CENTER

MULTI.
COUNTERSHAFT PINION OIFFERENTIAL
TRANSMISSION CROSS SHAFT
FORWARD REAR
COUNTERSHAFT
43P
or
AXLE CENTER AXLE CENTER
di
INPUT OUTPUT HIM TAIL II DIFFERENTIAL
DODEILEDDCEON
SHAFT ly*-SHAFT SHAFT RAFT PINION
IOLER th AXLE CENTER
OIFFERENTIAL
COUNTERSHAFT SHAFT CROSS 11

PINION
th SHAR DIFFERENTIAL

PINION
1114

IOW left hand

U 111441 eh tight head
f flout h head
Greer tail
I inner 0 outer
a nose p pocket
(6.1)
COorteSy of Tonkin Conirmy

294
6:2 BEARINGS AND SEALS

TYPES OF ANTI-FRICTION BEARINGS IDENTIFYING BEARINGS WHEN

ORDERING REPLACEMENTS
Anti- Iriction bearings are used when low fric-
tion and exact alignment are required. There 1. Most bearings have a number or num-
are numerous different types and sizes ber/letter combination stamped on them
manufactured today. but they can be grouped To order a bearing simply ask for that
into three basic designs. ball. roller. and stamped number. There is no need to
needle (Figure 6-2). Ball and roller are the identify the bearing location For example
more common bearings. Needle bearings are a bearing for a shaft in a generator could
used in compact spaces where extra stability be stamped 62032RS To order this
IS required. Bearing terminology is given in bearing lust request a 62032RS bearing
Figure 6-3,
2 Sometimes for one reason or another the
stamped numbers are difficult to read. In
this case, knowing the location 01 the
bearing. look up the bearing number in
the parts book. Note that parts books. as
well as giving part numbers. also show the
relationships of the parts by means of ex-
ploded view diagrams.
3 A general rule when ordering any part is
to err on giving too much information.
BALL ROLLER NEEDLE rather than not enough and then receiving
BEARING BEARING BEARING the wrong part.
16-2) ANTI-FRICTION BEARINGS
4. Always save the bearing being replaced
CourIosY of John Deere Ltd
so that you can compare it with the new
one. In this way you will be sure you are
WIDTH 14* installing the right bearing.
BEARING
BALL WIDTH
CUP LENGTH

OUTSIDE
OUTSIDE DIAMETER
DIAMETER
INNER RING
I
BALL RACE
BORE CONE

CAGE

OUTER RING ROLLER

BALL RACE
CAGE
(6-3)
BALL BEARING
TAPERED ROLLER BEARING

295
 BEARINGS AND SEALS 6:3

BEARING CAPACITIES SIX COMMON TYPES OF BEARINGS

Bearings are built with different capacities or Single Row Deep Groove Ball Bearings
load ranges.
The single row deep groove ball bearing (also
Bearing capacity is determined by many fac- called "limited-, non-loading groove and
tors most of which are not visible and cannot "conrad- type) has one row of balls rolling in
be appraised without special equipment In a single. deep groove in each race. Because
general though the capacity of a bearing 01 the height of the lands and the close fit of
depends on the balls to the grooves. these bearings can
stand a substantial thrust load even at very
size of bearing high speeds. Careful installation is necessary
number of rolling elements as these bearings demand more careful align-
ment between the shaft and housing than self
type of races aligning bearings. Single row deep groove
ball bearings are used for radial loads and
RADIAL AND AXIAL LOADING radial-thrust combinations. Because there is
ON BEARINGS little relative movement between the inner and
outer races. these bearings are often equip-
Each type of bearing is designed to do a ped with seals and shields. to exclude dirt and
specific lob One of the main factors affecting retain lubricant
the design of a bearing is whether the bearing
takes a radial or an axial load. A radial load is
a load carried al right angles lo the rotating
shaft An axial load (also called a thrust load)
is a load or a thrust parallel to the shaft.
Radial loading is a force acting vertically.
while axial loading is a force acting horizon-
tally
An example wilt illusliate the difference be-
tween the Iwo kinds of loads When a car is
running straight on a road the wheel bearings
take an upand clown radial load When the (6.5) DEEP GROOVE BEARINGS
car turns a corner there is a sideways or
horizontal thrust on the wheel bearings and Loading Groove Ball Bearings
the load shifts to an axial load
Ball bearings manufactured with loading
Some bearings are designed to take mainly grooves (known as "maximum" type (have a
radial loads le g . straight roller bearing). high radial capacity because they have many
some to take only axial loads 0 e . ball thrust balls between the races. However. they are
bearings) and others lo take combinations of not as tolerant of thrust loads.
axial and radial loads le g . tapered bearings)

RADIAL LOADS
SHAFT

LOADING
NOTCHES

(6-5)
AXIAL LOADS LOADING
BEARING GROOVE BEARINGS

(6 -4) LOAD FORCES ACTING ON BEARINGS

Courtesy 01 John Deere Lid

296
6:4 BEARINGS AND SEALS

Bali Thrust Bearings

Ball thrust bearings are designed for axial
thrust loads only. The load line through the
bearing balls is parallel to the shaft resulting
in high thrust capacity and minimum axial
displacement.
(6-5) BALL THRUST BEARINGS
Straight Roller Bearings
Straight roller bearings have very high radial
capacity, but low tolerance for misalignment
or thrust loads. They may be operated at high
speeds. Those which have locating ribs on
only one race allow for some axial movement
of the shaft in relation to the housing and are
easy to dismount. even it both rings are "press
fir. They are sometimes made with two or
more rows of rollers.

Tapered Roller Bearings (6-5) STRAIGHT BEARINGS

Tapered roller bearings are constructed so

that the roller centerlines and raceway sur-
faces form an angle with the shaft centerline.
They are. therefore. suitable for carrying
heavy combined radial and thrust loads. They
are separable the cup is mounted
separately from the cone (inner race and
rollers). Tapered roller bearings are usually
installed in pairs with one bearing facing the
other and both bearings must be adjusted for
preload or clearance.

Needle Bearings (6-5) TAPERED BEARINGS

Needle bearings are constructed of a series of

small diameter rollers. or needles. often in a
formed shell. Usually there is no inner race.
and sometimes no outer race or shell as the
needles run directly on the shaft or housing o:
inside the gear hub. They are usually used
only for light load. no thrust applications.
Some have rather high internal friction be-
cause no separator is used to keep the
needles from rubbing against each other.
Needle bearings are used mostly to align or
guide shafts. or to separate shafts where one
is inside another or where one is piloted into
another. However. there are some ap- (6-51 NEEDLE t'EARINGS
plications. particularly where space is at a
premium. where special-made. extremely high
capacity needles are used for heavy radial
loads. Needles used in these heavy ap-
plications are of a size and/or hardness to
classify them with roller bearings.

297
 BEARINGS AND SEALS 6:5

LUBRICATION OF ANTI-FRICTION needed to remove or replace it. If the outer

BEARINGS ring is a press fit in the housing. as in a wheel
hub bore. the outside diameter of the ring is
Lubrication is essential to the proper per- slightly larger than the housing bore.
formance of anti-friction bearings. The kind of
lubricant used is governed by the design of This fit or interference usually amounts to a
the bearings, the bearing load and the con- few ten-thousandths of an inch (.0001") in the
ditions the equipment is being operated un- case of small bearings. to several thousand-
der Lubricants perform the following func- ths in the case of large bearings.
tions for bearings:
Certain bearings are applied with tight fits on
can), away heal both rings and some with a loose ht on both
rings.
protect bearing surface from rust and
corrosion Tools For Removing Bearings
reduce friction between the bearing An arbor press. a hydraulic press. various
and its load. kinds of pullers. or some improvised tools can
Bearings are lubricated by either a grease or be used to remove a bearing. An arbor press
an oil Grease is used when a thickened and a hydraulic press are generally used to
lubricant is required mainly to overcome seal remove bearings in a shop. while pullers or a
leakage for example. in a wheel bearing. Oils nortable hydraulic press are used to remove
are used where a more liquid lubricant is bearings in the field. Whichever tool is used
required The oil must be contained by a the object is to remove the bearings without
housing and requires a good seal. The oil is damaging the bearing or the shaft. The
distributed to the bearing by splash or by bearing may be perfectly serviceable and can
Pressure feed. be reinstalled in the machine. Even if a
bearing is to be thrown away. it should still be
PRELOAD ON ANTI-FRICTION BEARINGS pulled or pressed out correctly as there is a
danger of a bearing exploding it it is
Preload is a load put on a tapered roller carelessly removed.
bearing prior to the bearing taking on its ac-
tual working load On some tapered roller Prior To Removing A Bearing
bearings the preload is built in. while on
others the preload must be adjusted. The Wash off the bearing housing. taking care to
means of adjustment is usually a threaded keep loose dirt from getting into the housing.
locking device or shims Take a few moments to study the assembly
Preload maintains exact alignment of a shaft and determine the best way to undertake
or gear. By making the rolling elements of the bearing removal.
bearing lay flat on the inner and outer races.
preload ensures that the load is carried evenly
and not just on the inner or outer ends of the
rollers.
Adjusting the preload is a very important ser-
vice procedure when installing tapered roller
bearings Specific adjustment procedures will
be clearly stated in the service manual.

REMOVAL AND INSTALLATION

OF BEARINGS

Bearing Fit
Ball and roller bearings are usually installed
with either the inner ring or the outer ring a
tight fit. If the inner ring is a tight fit it means
that the bore of the ring is slightly smaller
than the shaft diameter and some force is

298
6:6 BEARINGS AND SEALS

REMOVAL OF BEARINGS

General Rules For Removing Bearings

These rules apply whether using an arbor
press, a hydraulic press (shop or portable). or
pullers
1 Press or pull wherever possible only on
the ring which is tight.
2 Press or pull straight and square to keep
the ring from cocking which might score
the shaft or housing and could damage
the bearing.
3 Never press or pull against bearing dust Adiust tools to pull bearings straight and
shields or cage square
(6.6)
Various types of pullers are shown in Figure
6.6

(6-61
Where there is enough space behind a
bearing or bearing ring to admit a puller
always be sure that the puller is adtusted so
that it will not slip over the inner ring when
pulling pressure is applied U this happens
bearing parts can be severely damaged
(6-6)

Typical bearing pullers which may be used

Separately or in various combinations to puil
or push complete bearings or individual
rings
(6-6)

299
 BEARINGS AND SEALS 6:7

Removing Bearings With Arbor and Improvised Tools For Removing Bearings
HYdraulic Presses
Using proper care. bearings can be removed
Figure 6-7 shows the right and wrong methods quite safely with improvised methods when
of removing a bearing with an arbor or the right tools are not available (Figure 6-9).
hydraulic press. The press ram is pushing
down against the shaft on which the bearing A vise will do instead of an arbor press and a
inner ring is tightly fitted. The stripping is drift will take the place of the press ram. If the
being done by the support blocks under the shaft is held in the vise, protect its surface
nngs. The blocks must be the same size and with copper sheet or by hardwood blocks.
squared on all sides. When using a tube, drive alternately on one
Note. as shown in the wrong method that if the side and then the other to keep the bearing
support blocks are spaced too far out the from cocking.
pressure will be against the outer ring or If it becomes necessary to remove a bearing
shield. Damage will result as a heavy stress is by pressure not directly applied to the tight lil-
put on the balls or rollers which can injure ting ring, do not pound it off: use a puller or
them and cause indentation of both races. pry it off exerting even pressure.
Keep the press table and the blocks clean and Sometimes a separable inner ring is installed
square. Provide some means to keep the shaft against a shoulder of equal diameter so that
from falling to the floor. If the shalt and there is no way to get hold of it. Leave the
bearing are very large and the shaft end can- bearing ring on if it is usable. II not. cut it off
not be squared up with the press ram. turn up with a torch. Burn it part way through in order
two steel blocks to make a self-aligning fix- not to harm the shaft. It may loosen enough to
ture between the ram and the shaft. Protect pull off. If not. crack it through the rest of the
the end of the shaft with a pad of lead. copper way with a hammer and cold chisel, using
or other soft metal. precautions to prevent personal injury by
flying parts.

I
4.."
. .k
4 4..

ClItOTHER 0.
SOM MEM
MOLLER
SEARING SORE

A
$

TAPE OR
TO MANY
BLOCKS 1Amate6 cur
- n4cm.oaeR
WRONG Blocks RIGHT Blocks con. otos
contact the bearing tact inner ring - or 7 i-d
outel ring only both rings it bearmy is
flush faced
(6-7)

:4-144E,41:6'
"
To drive shall out of bearing. use a soft metal
slug which will not mar the 'bail
(69)
5

ARBOR PRESS HYDRAULIC PRESS

(6-8)
300
6:8 BEARINGS AND SEALS

BEARING REPLACEMENTS
As a rule when bearings are taken out they
are discarded and new ones installed. It is
more economic& to replace a bearing while a
machine is down than to reinstall the used
one, even though the used bearing may still
be serviceable. The reasoning is simple: a
new bearing contains more serviceable hours
than a used one Another consideration is that
it makes more sense to replace a bearing than
to risk damage due to bearing failure to the
more expensive part the bearing supports.
Note: Save the used bearing to compare it
with the new one so that you can be ir
roZt
sure you are installing the right f 7v-
bearing. Never pound directly on a bearing or ring. It
will likely damage both shaft and bearing.
When removing a bearing that has failed, take (6-9)
a half a mi:ute to examine the bearing for the
cause of failure. Some of the signs to look for
are:
1. metal fatigue bearing has worn out: it
ran over its serviceable life.
2. scored or scratched rolling elements
and/or races dirt contamination
possibly suggesting poor preventive main-
tenance. or metal chip contamination in-
dicating internal damage.
3. darkened or burned molal overheating tr. t:.

caused by lack of lilt- cation. If ring has been cut to remove. squeeze in
4. roller taper bearings worn on small vise and strike smartly at points indicated to
fracture it Be careful of shaft.
diameter the bearings were adjusted
too loose. (6-9)
roller taper bearings have darkening or
excessive wear on large diameter the
bearings were adjusted too tight.
5 rust, corrosion the bearings were not
lubricated properly.

30j
 BEARINGS AND SEALS 6:9

INSTALLATION OF BEARINGS

General Practices When Installing

Bearings
1. Clean shafts and bearing housings
thoroughly.
2. Clean dirt out of keyways. splines and
grooves. Remove burrs and slivers.
3. Clean and oil bearing seats.
A small amount of oil on bearing seat eases
4. Press bearings on straight and square. mounting helps prevent shalt scoring

5. Press only on the ring which takes the (6-10)

tight fit.
6 Press bearings until they are seated
against the shaft or housing shoulder
(See Figures 6-10 and 6.11.)
Bearing installation is lust the reverse of
bearing removal. Use an arbor press if
available and press the shaft into the bearing.
art
+14

supporting the inner ring on blocks as shown

in the sketch. Be sure the blocks don't scrape
the shaft or threads.
If the distance between the end of the shaft
and the bearing seat is fairly short. hold the
shaft in a vise and press the bearing onto the
shaft with a clean tube. This can be done
either in an arbor press or by tapping with a
hammer evenly around the tube.
-
Using tubing with squared ends to avoid
cocking bearing Center it before pressing
(6- 10)

(i;
_--r NEVER DO
THIS
OR
THI

Never use a hammer di, ocl on any Be Sure blocks will clear threads before A tough hardwood block used like
bearing it will result in damage forcing shaft into bearing this is 0 K protects end of tube
(6-1 1 I (6 -11) (6-1 1)

302
6:10 BEARINGS AND SEALS

If the end of the shaft is flush with the bearing.

use a drift or bearing installer. These are
made with flat ends to use with shafts which
are flush with the bearing and with coun-
terbores. as shown at the right to use where
the shaft projects beyond the end of the
bearing for a short distance. Tap lightly at first
to make sure the bearing or ring goes on
square and does not scrape or burr the
bearing seat. Be sure bearing is tapped to a
firm seat against the shalt shoulder.
Do not leave bearings exposed in partial
assemblies (Figure 6-12). Cover the bearings
until ready to complete the assembly. to
prevent damage by moisture. dirt or other
foreign matter. Any clean cloth or paper will
do so long as the bearings are well covercd.

The inner rings of large bearings are generally

Shrunk on shafts. This is a very simple Alter bearing os on far enough to align itself
operation consisting of heating the bearing or with shaft, drove to form seat against shoulder
inner ring in clean oil or temperature con- (6-11)
trolled oven to a temperature of between 200
and 250 F. (Figure 6-13). This expands the in-
ner ring sufficiently so it should slip over the
shaft to the bearing seat. Don't overheat the ain
oft
bearing or it will lose its hardness. Equipment
and methods as shown on preceding page are
still advisable for best results. a
If expanding the ring is not enough to get it
on. freeze the shaft in dry ice to make it shrink
smaller

Bearings on partial assemblies like this will

collect harmful dust or dirt if left standing too
long.
(6-12)

seo°41
IQ

Support bearing on blocks. well away from

bottom. Don't keep bearings on hot oil cr
oven alter correct temperature is reached
(6-13)

303
 BEARINGS AND SEALS 6:11

Good Practices When Handling

Bearings (Figure 6-13)
1. Keep bearings in original cartons or wrap-
pings until ready for use. If a package is
opened and gle bearing is not used im-
mediately. protect it by re-wrapping.
2. Keep the bearings clean and away from
moisture.
3.

4,
Don't scratch or nick bearing surfaces.
Handle bearings with clean hands and use
,t,
Get the habit of wiping tools and work
clean tools. Handle bearings as little as benches. Clean tools are half the battle in
possible. Finger marks are hard to wash keeping bearings clean.
off and perspiration starts corrosion
(6-13)
6. Don't take new bearings apart. They were
assembled correctly in the first place.
7. Don't spin any bearings with compressed
air.

Keep bearings in their original boxes and Never wash the grease Oil out of new
wrappings until they are to be mounted bearings. It is carefully selected and put
(6-13) there for bearing protection.
(6-13)

Clean hands plus clean rags mean cleaner

bearings and less chance of corrosion 'rom
perspiration.
(6.13)

,
304
6:12 BEARINGS AND SEALS

METHODS OF LUBRICATING 2. In a splash system check the oil level

ANTI-FRICTION BEARINGS regularly. Also inspect seals and vents
regularly.
Anti-friction bearings are lubricated by:
3. Clean the grease nipple before applying
1. a grease gun. e.g.. a pillow block bearing the gun. Clean the oil cap before
such as the one in figure 6-4. removing it.
Note: Grease guns are used less and
less as more bearings are pre- 4. Don't overfill. Too much grease or oil can
greased and sealed by the be just as harmful as too little. II overfilled.
manufacturer. grease or oil will ooze out of the housings
past the seals and enclosures. collect dirt
2. packing with grease (the bearing can be and cause problems such as overheating
packed by hand or 't can be prepacked The churning of overfilled lubricant. par-
and sealed by the manufacturer). e.g.. ticularly on high speed bearings. will
wheel bearings. cause the bearing to run excessively hot
and will result in it failing prematurely.
3. splashing or pressure feeding oil con-
tained in a housing. e.g.. transmission 5. When a wheel bearing is properly packed
bearings. the grease will completely fill the area
around the rolling elements of the race.
The frequency of lubrication is determined by With the hub properly cleaned, place
the load a bearing carries. the speed it moves enough grease in the hub to fill the area
and the temperature it operates under. For between the inner and outer cups as
example. a wheel bearing may not require shown by the shading in figure 6-14. This
lubricating as often as a pillow block bearing will act as a dam to prevent the grease in
used on a conveyor roller. Service Manuals the bearing from running out when heated
will give bearing lubricating schedules in operation. Set the inner bearing into the
hub and install the grease seal. The wheel
Good Lubricating Practices assembly should then be installed on its
I Consult the service manual for lubrication shaft, the outer bearing installed and ad-
schedules and for the correct type and justed.
amount of lubricant to use. 6. On oil hubs. the hub must be partially
filled with oil before assembly.

FRONT WHEEL (6.14) REAR WHEEL

Courtesy 0 Tsmksn Company

305'
 ...
BEARINGS AND SEALS 6:13

BEARING ADJUSTMENT
Tapered roller bearings must be adjusted to
give the bearing the correct running
clearance or pre-load and then must be
locked into position. Below are some common
bearing adjusting devices. The list is intended
to give a general idea of bearing adjustments.
Service manuals will give the exact
procedures for how to adjust specific
bearings. Always use a torque wrench to get
an accurate adjustment.

Common Bearing Adjusting Devices

1. Slotted hex nut. cotter pin. on a threaded
shaft. e.g.. front wheel bearings on
automobiles or light trucks.
Method of adjusting:
rotate the wheel. tighten nul till slight
bind. back off nut. lock the nut with the
cotter pin.
2. Two standard lock nuts and a tongued
washer. e.g.. highway trailer wheels.
Method of adjusting:
rotate the wheel. tighten the adjusting
nut until a slight bind. back off adjusting
nut. tighten the jam and lock nut.
3. End cap and shims e g.. transmission
bearings and axle carrier bearings.
Method of adjusting:
(a) A shim pack is selected that will
give the correct bearing running
clearance.
(b) Or sufficient shims are removed or
added to give a slight bind or pre-
load on the bearings.
The end cap is locked with cap screws
and lock washers or lock wires.
4. Threaded cup followers, cap screw and
locking plate. e.g.. dillerential bearings:
Method of adjusting:
adjust the follower to specified
clearance and lock the follower by sit-
ting the plate in the lugs or holes in the
follower.

306
6:14 BEARINGS AND SEALS

BEARING TERMINOLOGY Press fit mounting with interference. i.e..

(Courtesy of International Harvester Co. bore of bearing is smaller than OD of shaft. or
of Canada Ltd.) OD of bearing is larger than bore of housing.
or both.
Axial parallel to the shaft or bearing bore.
Push fit this means that the part of the
Carburixinj addition to metal of the bearing termed ''push ht can be slid into
element carbon for hardening purposes place by hand. if it is square with its mounting.
Case harden hardening the outer surface Raceway the surface of the groove or path
of metal to a given "case" or "shell" depth. on which the balls or rollers of a bearing roll.
while leaving the inner portion "soft" to ab-
sorb shocks and squeezing (see carburizing). Radial perpendicular to the shaft or
bearing bore.
Creep the very slow, steady rotation of a
'push fit- bearing race. either inner or outer. Radial clearance (Radial displacement)
in order to constantly keep changing the area clearance within the bearing and between
of greatest load, to increase bearing life. balls and races perpendicular to the shaft
"Push fit" bearing races creep because of the
squeezing action of the bearing balls, causing Radial load a 'round the shaft" load. that
the relatively loose push fit race to act like a is. one that is perpendicular to the shalt
cam and propel itself around and around its through the bearing.
mounting. Remember that one rotation of a Separable either the inner or outer race or
race by creep may result only after several both may be removed from the bearing assem-
thousand revolutions of the rest of the bly.
bearing.
Spherical ball-like. rounding. or like a por-
Crowned a very slight curve in a surface tion of a ball.
(may be on a roller or raceway).
Thrust load -- a load which pushes or reacts
Deflection bending or movement away through the bearing in a direction parallel to
from normal due to loading. the shalt.
End play (Axial displacement) that
amount of axial movement in a shaft due to
clearance in the bearings.
End shake end play (see above) within a
bearing.
Heat treatment heating. followed by fast
cooling to provide required hardness or
metallurgica I structure.
Loading grooves filling notches machined
into side of races to permit loading of more
balls or rollers.
Load line a centerline indicating the points
of contact within a bearing through which the
load would pass.
Load line angle the anale of a load line
with respect to the shaft center or bearing
radial centerline.
Misalignment when bearings are not on
the same centerline within good functional or
working limits.
Pre-load a load within the bearing. either
purposely built in. or resulting from ad-
justment.

30 7
 BEARINGS AND SEALS 6:15

QUESTIONS BEARINGS
1. Name three main purposes of anti-
fric lion bearings.
2. What are the two load forces acting on
bearings? Describe them.
3. What are three basic types of anti-
friction bearings? Give the type of load
each will carry.
4. II the stamped number is not readable on
a used bearing, how would you go about
ordering a new one?
5. The genera: rule is to
bearings when they are taken out.
6. What are the three factors that govern
the capacity of a bearing?
7. How do tapered roller bearings differ in
their load carrying ability from straight
roller or ball bearings? Give two exam-
ples where tapered roller bearings are
commonly used.
8. What three functions must a lubricant
perform for bearings? Where would
grease be used instead of oil to lubricate
a bearing?
9. Referring to tapered roller bearings. what
does the term pre-load mean? Why is it
necessary?
10. What tools are commonly used to remove
bearings in a shop? In the field?
11. Where should the stripping blocks be
placed when removing a bearing with an
arbor press?
12. If a bearing is press-fit on a shaft, at what
point would you apply pressure to
remove it?
(a) the outer race
(b) the inner race
(c) either the inner or outer race: there
is no difference
13. True or False? Grease bearings liberally;
extra grease won't hurt them.
14. A small amount of ______ on a
bearing seat makes mounting the
bearing easier and helps prevent shaft
scoring.
15. True or False? It's an acceptable prac-
tice to spin dry bearings with com-
pressed air.

308
 6:16 BEARINGS AND SEALS

ANSWERS -- BEARINGS 9. Pre-load is a load put on tapered roller

bearings prior to the bearing taking on
1. Support a moving part. its actual working load.
Reduce friction. It makes the rollers lay flat on the inner
Reduce wear between moving parts. and outer races to ensure that the load is
Provide a replaceable wear surface. carried evenly and not just on the inner
or out..( ends of the rollers.
2. Radial load a load acting at right
angles to the shaft. 10. Shop arbor press. hydraulic press
Axial (thrust) load a load acting Field pullers. portable hydraulic press
parallel to the shaft. 11. Under the inner ring close to the shaft.
3. Ball bearing radial and some axial or 12. (b) the inner race
thrust loading depending on the par-
ticular bearing construction. 13. False.
Roller bearing basic straight roller 14. .... 011...
bearing carries only radial loading.
Tapered roller bearings carry radial and 15. False. Never spin bearings with com-
axial loads. pressed air.
Needle radial loading. or axial depen-
ding on how it is made.
4. Knowing the location. look up the
bearing number in the parts book.
5. .... replace ...
6. Size of the bearing
Number of rolling elements
Type of races
7. Tapered roller bearings carry heavy.
combined radial and axial (thrust) loads.
They are used in:
wheel bearings
final drives
drive axles
transmissions
steering gears
8. The lubricant must:
carry away heat from the bearing
protect the bearing surface from rust
and corrosion
reduce friction between the bearing
and its load.
Grease is used mainly to overcome
leakage in places where oil would be
difficult to contain.

309
 BEARINGS AND SEALS 6:17

SEALS Seals are required to do one of the following

jobs:
PURPOSE OF SEALS
1. Retain fluids
Wherever metal parts fit closely together and
one part turns within the other. e.g.. a shaft ex- 2. Exclude dirt.
tending from a transmission case, something 3. Hold a pressure.
is needed to keep the oil from leaking out and
to prevent dirt from entering the case. The 4. Hold a vacuum.
metal parts could be made precisel, enough
so that no fluid would leak. but this kind of Figure 6-15 shows the location of grease seals
precision would be too costly to manufacture. most often replaced in tractors, trucks.
Thus the need for seals. trailers, and buses.

Seals are essential parts of modern

machinery. For example, the seal in the
hydraulic cylinder of a dozer holds the oil un-
der pressure allowing the blade to be raised
and lowered. Seals are necessary to seal in
the fluid in the brake system. or. if the brakes
are power assisted. to seal the vacuum cham-
ber.

GREASE SEALS IN TRACTORS, TRUCKS, TRAILERS AND BUSES

ACCESSORY TRANSMISSION AUXILIARY TRANSMISSION SEALS ALSO

OIFFERENTIAL
FRONT DRIVE FRONT TRAILER
PINION I
WHEEL SEALS SEALS TRANSMISSION WHEEL
SEALS ii SEALS
AXLE DIESEL REAR
SEAS BLOWER SEALS
SEALS 1

) I

)
I
) I

REAR
STEERING CRONY REAR POWER WHEEL
SEALS CRANK CRANK TAKEOFF (INNEMOUTER)
SEALS SEALS SEALS SEALS

(6-15)
CourteSy of C R Industries

310
6:18 BEARINGS AND SEALS

TYPES OF SEALS Since each seal is designed to do a specific

job. replacement seals must be the exact type
There 'e two basic types of seals" shown an the manufacturer's parts book. Note
1 Dynamic seals used to seal moving that seals are usually harder to identify than
parts. e.g.. wheel seals. bearings because the numbers on a removed
seal are often very faint or completely
2. Static seals used to seal stationary unreadable. Always check a new seal
parts. e.g.. gasket. carefully to be sure it is the right one. i.e.. its
outside and inside diameter. width and
Its inaccurate to think of seals as being sim-
sealing surface.
ple parts. Many complex factors are con-
sidered in designing a seal. factors such as: DYNAMIC SEALS
What pressures on the seal are ex- Six types of dynamic seals are.
pected (if any)?
1. Radial lip seals.
At what temperatures will the seal
operate? 2. Exclusion seats.
Is the seal material compatible with the 3. Metal ring seals.
fluid it will seal? 4. Metal face seals.
Will the seal fit sufficiently tight to do 5. Compression packings.
its job without wearing too rapidly or
causing excessive friction? 6. 0-rings.
Will the seal material score or scratch
the polished metal surface? Radial Lip
Radial lip seals generally are used to seal
Will there be flexing as well as rotary or
revolving shafts which extend from housings
axial movement of the part? containing fluids. They are usually called
rotating shaft seals. A typical lip seal is shown
in Figure 6-16.

1 Outer metal shell

2 Inner metal shell
3 Steel garter spring
4 Auxiliary dirt lip.
5 Synthetic bonded seal-
ing member. Its sealing lip
Is held against the shaft
with an exact uniform
pressure by the garter
spring. The sealing lip
should always face the
lubricant being sealed. FRONT

Courtesy 0 C R Industries

au
 BEARINGS AND SEALS 6:19

A lip seal can be bonded. its flexible sealing Lip Seal Operation
material formed and bonded onto a metal
case. or it can be assembled. its parts made A radial lip seal is press fitted into a housinV
separately and then assembled and crimped bore The lip of the seal contacts the shaft
to an outer case (Figure 6-17). thus retaining the fiuid contained within and
helping to prevent dirt from getting into the
system. Note that complete sealing is not
desired. What is wanted is a slight leakage
which leaves a thin film of oil on the shaft that
lubricates and helps to cool the moving parts.
The tension of the lip contact is usually set by
a spring in the seal. This spring tension is very
important to the correct operation of the seal.
Excessive tension would cause too much fric-
tion. loss of oil WM, premature failure of the
seal and even wear on the shaft. Insufficient
X2997 tension would allow excessive leakage.
BONDED SEAL ASSEMBLED SEAL Exclusion Seals
Courtesy of John Deere Lid
Exclusion seals are used to exclude or
prevent entry of dirt and other unwanted con-
Lip seals are classed by the type of lip. Single taminants that would damage the moving
lip not spring loaded. single lip spring loaded. parts. For example. an exclusion seal is
and double lip are three of the most common needed to prevent scoring of a piston rod on a
lip types (Figure 6-18). hydraulic cylinder. Figure 6-19 shows a typical
radial exclusion seal.

SEALING EDGE It
CONTACT
1. LIP HEIGHT
PRESSURE
CONTACT
WIDTH LIP

BORE

0 SINGLE LIP SEAL 0 SINGLE LIP SEAL CONTACT

SURFACE GROOVE
Nor SpringLooJed Lip SptingLooded
HOUSING
4.----------<"-- ,)
V JJ;

Il XJ063 I' SHAFT 4-.1CLEARANCE

(6-19) RADIAL EXCLUSION SEAL
Courtesy of John Deere Lid

Exclusion seals are often used in conjunction

with a single lip radial seal: the exclusion seal
keeps out unwanted materials while the lip
seal retains the fluid. The two seals are in-
stalled next to one another with the lips facing
in opposite directions. These seals are not in-
terchangeable.
0 DOUBLE LIP SEAL
One Lip SpringLooded

(6-18) BASIC LIP TYPES OF

RADIAL LIP SEALS
Courtesy Of John DOOM LW

312
6:20 BEARINGS AND SEALS
Types 01 Exclusion Seals
Wipers sealing is done by a wiping action
of a stationary leather or rubber lip, often on
reciprocating shafts.
Scrapers stationary metal lip scrapes
heavy clinging material off reciprocating SEALING POSITION
shafts (Figure 6-20).
(6-22) STEP SEAL RING
Counesy of John Deere Ltd

t
SEALING POSITION
CONICAL SCRAPER RING SCRAPER

(6-20) SCRAPERS (6-22) STRAIGHT-CUT SEAL RING

Courtesy of John Deere Lid
X3004
Counesy of John Deere Ltd

Boots boots differ from the above seals in OMPRESSION

that there is no actual se. g by frictional RINGS
contact. A boot is a I. "'dr flexible cover
EFOIL CONTROL
(Figure 6-21). RINGS
RI

PUSH ROD

$tr
tkat

:5'

X 2862 mmoiwn
(6-23) SPLITING SEALS ON
AN ENGINE PISTON
(6-21) Counesy of John Deere Ltd
Courtesy of Bendix Corporation

Metallic Ring Seals

Metallic ring seals are used to seal
pressurized fluids or air on reciprocating
parts. e.g.. piston rings in an engine. They
also are used to form a channel on a shaft to
direct oil from a housing to a shalt. e.g.. rings
on a shaft in a power shift transmission. The
expanding split ring design (Figure 6.22) is
the most common metallic ring seal. Figure 6-
23 shows ring seals on a piston.

313
 BEARINGS AND SEALS 6:21

A metallic ring seal in a free state is larger Metallic Face Seals

than the cylinder bore it will fit into. When in- (Floating Ring Seals)
stalled in the grooves on the piston and com-
pressed to lit the bore. the ring applies a Metallic face seals (Figure 6-24) do an ex-
pressure contact to the cylinder walls forming cellent job of sealing under severe conditions.
a seal. Having exclusion as well as inclusion
capabilities makes them ideal for use in heavy
Ring seats require a thin film of oil between equipment in such places as:
the outside of the seal surface and the bore it
runs in to reduce friction and prevent scoring. Track Rollers
Idler Rollers
Note that the ends of a split ring when com-
pressed are required to have a slight Front Idlers and
clearance to allow for expansion. The type of Final Drives
end joint will depend on what is being sealed
and under what amount of pressure. Two
types of joints are shown in Figure 6-22.
RUBBER WASHERS

SEALING RINGS

SEALING SURFACES
(6-24) Courtesy 0$ J I Case

SEAL CONTACT AREA Tne two mated seal rim?) s of metallic face
seals are precisely lapped to one another. In
operation the sealing faces have a narrow
contact at the outside diameter (Figure 6-25)
and the remainder of the faces are tapered
back slightly. As the seals wear the area of
contact increases. moving across the width of
the seal.

0-RINGS (TORRIC SEAL RINGS)

(6-25)

314
6:22 BEARINGS AND SEALS

The metal sealing rings are held in contact by

0-rings also referred to as torric seal rings.
One metal seal ring and its 0-ring is fitted into
a housing bore of a stationary part, while the
other seal ring and 0-ring is fitted into a bore
of a moving part as is shown in Figure 6-26.
SPRING-LOAOING
OEVICE
METAL CORE BRAIDED CORE
(OPPOSED USHERS)

STATIC STATIC
SEAL SEAL
METALLIC PACKINGS
X3018
ROTATING (6-27) STRING PACKINGS
SHAFT
Courtesy of John Deere Ltd
HOuSING Molded. compressed pack ings are circular
(STATIONARY)
rings made of various materials compressed
into definit "U" or "V" cross - sectional pat-
terns. The compressed rings come in various
sizes depending on the shaft bore they are to
fit. Several of these molded rings are used
with metal back up rings on either side. one of
which may be spring loaded. Figure 6.28
shows molded "V" packings (with back up
STATIONARY ROTATING rings) used to seal a reciprocating shaft.
SEAL RING SEAL RING
X30 IS
(6-26) ADJUSTING NUTS
Courtesy of John Deere Ltd
Compressed Packings
Placed in a stuffing box next to a moving shaft
or rod. packing material is compressed to
form a seal against the shaft or rod. For exam-
ple. packing is used to seal rotating shafts in
pumps. or to seal reciprocating shafts such as
a piston or a piston rod in a hydraulic cylinder.
4FEMALERING
SUPPORT

There are two basic kinds of packing: string

packing and molded ring packings ("U" or PACKINGS
"V'' types). 4
String packings are generally woven and MALE ERSINIPORTO
twisted asbestos fibres or strips of soft metal
formed into round. square or rectangular
shapes of various thicknesses (Figure 6-27).
GLAND
The packing strands are treated with grease
and/or graphite. or with teflor.. which fs be-
(6.28)
coming Increasingly popular. String packings
are sold in rolls and cut at the required
lengths.
Compression packing is installed in a stuffing
box or counter bore over the shaft t will seal
and squeezed to a proper fit by an adjustable
gland. This gland may be a bolted flange as in
Figure 6-28 or a threaded adjuster ring.
Glands require frequent adjustment to com-
SOFT BRAIDED D AGONAL pensate for packing wear.
CORE CORE LAMINATED

FABRIC PACKINGS
The size of compression packing is very im-
portant. If too small. it will require too much
(6-27) compression to seal. If too large. it will cause
Courtesy of John Deere Ltd

315
r=MNid

BEARINGS AND SEALS 6:23

the joint to be tight and overheat. Com-

pression packing. like other seals discussed.
needs a slight film of oil between it and the
shaft. otherwise it will wear rapidly.

0-Rings (Dynamic Seals)

0-rings are the simplest and yet the most
common of all Beals. They can be used to seal INCORRECT. NO ROLLING AC.TION
revolving shafts. reciptocating piston or
piston rods. or oscillating parts that move in a
forward and reverse direction.
There are many types of 0-rings differing
mainly in their cross-sectional shapes (flat.
rectangular. square. round). and in the
materials they are made of. The most common
ones are round and are made of a synthetic
material such as neoprene which is im- c=i filik 1E*
pervious to most fluids. 0-rings generally
have a slash of color paint to identify
operating temperature or compatibility with CORRECT ROLLING ACTION
fluids. (6-29) Courtesy 01 John Deere Ltd

0-rings are designed to fit in a groove and to

be squeezed slightly. The groove is a little STATIC SEALS
wider than the ring to allow it to spread out Static seals are used to seal non-moving
when squeezed and to move from side to side parts. Three types of static seals are:
in the groove. In some places, where 0-rings
are under high pressure. back up rings will be Gaskets non-metallic paper, cork
used to reduce chipping of the seal. asbestos. rubber and plastic.
Figure 6-29 shows the use of incorrect and metallic corrugated thin metal
correct sized 0-rings with respect to squeeze (copper steel aluminum), metal
and rolling action. jacketed, with soft filler (copper
steel aluminum with asbestos
FORCE 43. filler).
0-Rings rubber, neoprene, plastics (nylon.
teflon) and metal.
Sealants Hardening. non-hardening. and
tapes.

CUT
INCORRECT: TOO-LARGE RING

4 FORCE

CORRECT: SLIGHT SQUEEZE

(6-29) 0-RING SQUEEZE

Courtesy of John Deere 1.1d

316
6:24 BEARINeS AND SEALS

Gaskets Minimum stress required depends on:

Gaskets provide a seal against the movement Material cork would not require as much
of fluids or gases across two mated surfaces stress as an asbestos gasket.
of a housing or across the mated surfaces of a
housing and a connecting container. Same Pressure higher pressures require more
gaskets are installed with sealing pastes or stress to seal.
liquids. while others are installed dry. Figure Fluid sealed type and viscosity of the
6-30 shows some common types of gasketed sealed fluids affect the required stress.
joints.

BASIC FLANGE

MER_

METAL-TO-METAL
ELL

THREADED

(6-30) COMMON TYPES OF GASKETED JOINTS Flange finish a rough flange surface
COMESY of John Deere Ltd. requires greater stress for the gasket to con-
form than does a smooth flange surface
The joints between two stationary. mated sur- would.
faces is only as good as its gasket. Gaskets
must be of suitable material to seal the sur- 0-Rings (Static)
faces and they must be installed correctly.
Gasket fit refers to the term "minimum stress A static 0-ring is a type of gasket that seals
required". the minimum amount of stress it the movement of fluids across two mated sur-
takes to make the gasket material conform to faces. Figure 6-32 shows two static 0-ring in-
the irregularities of the flange faces and thus stallations.
for a seal (Figure 6-31).

FLANGE

GASKET

1.--;LANGE
NO CONFORMATION FULL CONFORMATION
Bad Good

(6-32)
X3033 NON-METALLIC STATIC 0-RINGS
X3031 IN FLANGE JOINTS
(6-31) CONFORMATION OF GASKET TO FLANGE (TWO TYPES OF RECTANGULAR
GROOVES SHOWN)
Courtesy 01 John Deere Lid
Courtesy of John Deere Ltd.

327
 BEARINGS AND SEALS 6:25

Like dynamic 0-rings. static 0-rings fit in a 3. Be sure the seal. the shaft. the seal bore
groove and are squeezed or compressed by or groove is absolutely clean on assembly.
about 10% of their thickness. It is important to
install the correct size 0-ring as one too large 4 If a seal is leaking don't just replace the
will squeeze out between the flange, and one seal take a quick look for the cause of
too small will not have sufficient tension to the leak.
seal. As well as normal frictional wear. possible
Sealants causes could be (Figure 6-34):
Sealants perform a job similar to that done by worn shaft support bearings allowing
(a)
gaskets. Where a gasket is a set shape and excess movement of the shaft.
size though. a sealant is applied in liquid or
paste form. Sealants are generally applied to (b) plugged vent creating excess
a joint that has less pressure and lower tem- pressure within the housing.
perature than a joint where a gasket would be (c) worn or scored shaft seal surface
used. Sealants are also used to provide a high temperature.
(d)
protective coating, to reduce noise and to aid
in sealing gaskets. Sealants can be applied by (e) what looks like a seal leak could be
brush, tube. or spray (Figure 6-33). In fact a loose bolt. a cracked
housing. or a worn gasket.
O e..

V046 BRUSH TUBE SPRAY

Sealants may be broadly classed as: Courtesy of John Deere Ltd

(6-33)
Hardening these may be rigid or flexible GASKET BOLT-ON
when dried. HOUSING

Non-Hardening these never really dry and

are used on low stress joints more as SEAL
adhesive than as sealants.
Sealing tapes are also available. They come
in a variety of types, but the most common one
is teflon tape. The main purpose of the tape is
to seal brass or iron pipe threaded fittings.
The tape is wrapped around the male thread
one or two times and as the fittings are
screwed together, the tape spreads between
the threads to help form the seal. SHAFT
GOOD PRACTICES WHEN REMOVING AND
INSTALLING SEALS
1. Never install an old seal. If a seal is BORE
removed. it should be replaced wtih a new GASKET i LEAKAGE
one.
X MO LEAKAGE i I
2. Use only the correct seal recommended (6-34) COMMON TYPES OF OIL LEAKS
by the manufacturer. Do not substitute Courtesy of John Deere Ltd
seals.

318
6:26 BEARINGS AND SEALS

REMOVING AND INJTALLING SEALS Installation

Following are some tips and procedures for The installation points given for lip seals and
removing and installing radial lip and ex- for the other seals following are general; for
clusion seals. metal face seals. compression specific procedures see a service manual
packing. 0-rings and gaskets.
1. Clean and file smooth any nicks or burrs
RADIAL LIP AND EXCLUSION SEALS from the housing bore and the shaft.
Removal 2. Coat the seal surface with oil or light
grease.
Remove the seal by using one of the following
methods: 3. If the seal has a metal case, coat its out-
side diameter sparingly with a light film of
slide hammer puller with reverse jaws gasket cement.
drift and hammer 4. Place the seal in the housing. putting the
lips toward the fluid it will seal. Using a
heel bar or pry bar. hammer and the seal installation tool
Once the seal is removed carefully examine it (Figure 6-35) with the correct I.D. and 0.0.
for signs that may point to the cause of failure. adapters. carefully drive the seal into
e.g.. position. Do not strike the new seal
directly with the hammer or metal tool. If
seal is hardened possible over heating. the correct tools are not available, select
seal is soft or swollen incompatibility of a round ring such as an old bearing cup
fluid with seal material. which fits the 0.0. of the seal to drive in
the seal. A square block of wood would do
seal lip is worn normal fatigue. or as well. Be sure not to drive on the inner
possibly excessive shaft movement. diameter as this will damage the lip and
cause early seal failure.
5. A seal can be easily damaged. When a
shaft with splines or threads must be
passed through a seal improvise a sleeve
to protect the seal.

SOME OF THE FIXTURES USED FOR PROPERLY INSTALLING A LIP-

TYPE OIL SEAL:
0 AN INSTALLATION TOOL IS EMPLOYED TO PRESS FIT THE SEAL
IN A HOUSING BORE PRIOR TO INSTALLING THE SNOT. THE 0.0.
OF THE TOOL IS SLIGHTLY SMALLER MAN THE 0.0. Or THE SEAL

0 A CONE IS USED TO PERrl THE SEAL TO PASS OVER SHARP

CORNERED SHAFT ENOS.

0 A SLEEVE wILL PROTECT EDGES LIp wHEN PASSING OVER

KEYWAYS. SPLINES, SHARP EDGES OR ROUGH SURFACES.

0 A TOOL FOR ',WALLING AN OH. SEAL OVER A SHAFT MUST

APPLY PRESSURE EVENLY AND NEAR THE OUTER PERIPHERY
OF THE SEAL. SEAT SEAL WELL WHIN THE HOUSING BORE.
ALLOW FOR SHAFT AND BORE CLEARANCE IN AND AROUND
THE TOOL. MOS
(6-35) Tools For Properly Installing Lip-Type Oil Seals
Courtesy or John Deere Ltd.

...
319
 BEARINGS AND SEALS 6:27

METAL FACE SEALS GASKETS

(Floating Ring Seals)
Removal
Removal
Removing a gasket is a straight forward
After the part using the metal face seal is procedure. Even if a gasket is not damaged
disassembled. simply pull the seal halves from on removal. always replace It with a new one.
the housing.
Installation
Installation
1. Clean all old gasket material from the
1 Metal face seals are the exception to the housing and flange faces and clean all
rule that seals are not reused. Providing threaded holes. Smooth all burrs and
that the mating surfaces of the seals are sharp edges with a file.
not worn more than 1/3. the pair of metal
face seals can be reinstalled. 2. Check for cracked bolts. for flange cracks
or damage. Using a straight edge check
Note- Only install a pair that has run the flange faces for warpage. Make any
together: never install a new ring necessary repair or replacement.
seal with a used one. Toric rings
are never reused: always install 3. If a ready made gasket is not available
new ones. select the correct type and thickness of
gasket material and make one.
2. Clean: smooth and dry the seal support
bores. 4. On assembly carefully align the gasket
with holes in the housing. It may be
3 Ideally a metal face seal installation tool necessary or helpful to use an aid such as
can be used Be sure that the toric seal line up studs. gasket cement. or grease to
ring accompanying the metal face seal is hold the gasket in place.
installed flat and straight in the bore.
5. Some gasket locations require a sealant
4 If an installation loci is not available use to help form the seal. On the other hand.
finger pressure (not a screw driver) to in- cork gaskets and metal exhaust gaskets
stall the toric ring. and be sure the metal are usually assembled dry.
face seal is sitting level in the support
bore (Figure 6-36). 6. Torque all bolts in sequence to specified
pressure.
5. Clean the two metal faces and coat them
with a slight firm of light oil. COMPRESSION PACKINGS

Removal

FIG A Remove the packing gland. the back up ring.

1.."k"
and pry out the packings.

Installation
FIG 1 Clean the packing bore. the shaft. the
gland. and back up rings with solvent and
blow them dry. File or emery smooth any
burr or nicks on the shaft. bore or gland.
Replace worn or damaged parts.
FIG C
2. When installing packing rings:
INSTALLING FLOATING RING SEAL Lubricate liberally each ring of a new
AND TORUS SEAL packing.
iTorus seal 2Floating rir.g seal. 3Location
to press on seal X-Dimension Install the packings with the "V" point-
to be checked ing toward the gland.
(6-36) Stagger the diagonal split joints of the
packing rings.

320
6:28 BEARINGS AND SEALS

3. Cycle the unit and check the gland ad-

justment
4. Don't over tighten. The gland should be
tight enough to prevent leakage but loose
enough to coat the shaft or rod with a thin
film of oil.
0-RINGS

Removal
Removal of 0-rings is a straight forward
procedure.

Installation (Dynamic 0-rings)

Care must be taken not to damage the 0-ring
on installation:
1. Clean and smooth the seal groove.
2. Select the correct size and type of seal
(0-rings often have an identifying point
slash). Be sure. too. that the seal is com-
patible with fluid it wil! seal.
3. Lubricate the seal with the same fluid as
in the system.
4. Avoid stretching and twisting 0-rings on
installation Also. protect them from sharp
edges.
5. After installation. cycle the unit several
times to allow the seal to find its normdl
position.
6. Properly installed. 0-rings should pass a
slight film of oil for lubricaton to prevent
scuffing.

Installation (Static 0-rings)

There is a little more tolerance for installing
static 0-rings but care still must be observed:
1. Clean the groove and flange faces.
2. Select the correct size and type of 0-ring.
3. Align the parts carefully and the torque
flange evenly.

321
 BEARINGS AND SEALS 6:29

QUESTIONS SEALS
1. What are the two basic types of seals
and what is each used for?
2. Name three jobs a seal may be required
to do.
3. When installing a lip seal. is it desirable
to have a slight leakage? Explain.
4. When installing a lip seal. which way
should the lip go?
5. Which has more positive sealing action.
a lip seal or a metallic face seal? Under
what type of conditions are metallic face
seals used?
6. Should compression packings allow a
slight leakage when adjusted correctly?
Explain.
7. What effect does gasket material have
on minimum stress required to make the
gasket conform to the irregularities of
the flange faces?
8. When an 0-ring is used as a static seal.
how much should it compress? What
would happen if an 0-ring that is too
large is used?
9. Bores. shafts. and flange surfaces should
be before installing a new
seal or gasket.
10. Which is the accepted rule when an old
seal is removed?
(a) Carefully inspect it. and. if not too
badly worn. reinstall it.
(b) Replace it with a new one.
11. A tool should
be used when installing a lip seal.
12. Can metallic ring seals be reused? What
about the toric or tension 0-rings?

.. 322
6:30 BEARINGS AND SEALS

ANSWERS SEALS
1. Static seal seals stationary parts.
Dynamic seal seals moving parts.
2. Retain a fluid
Exclude dirt
Hold pressure
Hold a vacuum
3. Yes. a slight leakage lubricates the
moving parts and helps to cool them as
well.
4. Towards the fluid it will seal.
i
5. A metallic face seal. Metallic face seals
are used in severe conditions that
require a strong. positive seal (e.g.. track
rollers).
6. Yes. for the same reason as lip seals: to
lubricate and cool the moving part.
7. A soft material conforms easier than a
harder one and therefore less stress is
required to form a seal with a gasket of
soft material.
8. About 10%. Too large an 0-ring will
squeeze out between the flange faces.
9. . .. cleaned ...
10. (b) Replace it with a new one.
11. . . . seal installation . . .

12. Yes. metallic ring seals can be reused

providing that the sealing surfaces are
not more than 1/3 worn. The toric 0-
rings. on the other hand. should always
be replaced.
 BEARINGS AND SEALS 6:31

TASKS BEARINGS AND SEALS

SEALS
1. Remove front wheel seal. and install a
new seal using the correct size seal
driver.

ANTI - FRICTION BEARINGS

t Using the correct type and size of pullers
or pressing equipment. remove and install
bearings located. for example. in a track
machine final drive or in any location
where bearings are installed with a press
fit.
2. (a) Remove all the bearings from a front
wheel assembly. clean the bearings
with petroleum solvent and inspect
them. Replace any bearings that are
not serviceable.
(b) Using the correct type of grease
specified in the service manual pack
the front wheel bearings.
(c) Install the bearings.
(d) Taking a torque wrench. adjust the
front wheel bearing to the preload or
clearance specified by the manufac-
turer.

324
 TRACK MACHINE UNDERCARRIAGE 6:33

PURPOSE OF TRACK MACHINE CRAWLER LOADER AND CRAWLER

UNDERCARRIAGE DOZER UNDERCARRIAGES
The term undercarriage refers to the complete The undercarriage design for crawler dozers
assembly that supports a track machine. The and loaders is virtually the same a track
undercarriage of a dozer or loader includes chain with bolt-on shoes is driven by a
two track frames, the components mounted on sprocket located at the rear of the machine.
the track frames, and the tracks. The un- The track follows a path over the carrier
dercarriage of a shovel or excavator includes roller(s) attached to the topside of the track
the track frame unit (called the truck frame or frame, around an idler at the front of the
carbody), the components attached to the machine. under track rollers attached to the
track frames, and the tracks. underside of the track frame, and finally back
to the sprocket. Figure 6-37 shows a dozer un-
The purpose of undercarriages of crawler dercarriage, and Figure 6-38 a loader un-
loaders. crawler dozers, excavators shovels or dercarriage.
cranes is to:
support the machine
drive the machine
provide ground flotation
The question might be asked. wny are tracks
necessary? Couldn't rubber tires do the job?
The answer is no: rubber tires will not give the
flotation. traction and mobility that track
machines need to work in soft. rough. or
uneven terrain,

GROUSERS

TRACK
SHOES IDLER

PINS a
aUSHINGS

TRACK ROLLER
FRAME
TRACK ROLLERS \MP' LINKS
BASIC UNDERCARRIAGE COMPONENTS

(6-37) Courtesy of Caterpillar Tractor Co

32g
6:34 TRACK MACHINE UNDERCARRIAGE

Carrier rollers

Final
drive case

Links

Sprocket

Idlers
Track roller frame

Track shoes Double grousers

Track rollers Hardbar
End guiding gsard
Pin and bushings
Courtesy of Caterpillar Tractor CO.
(6-38)

327
 TRACK MACHINE UNDERCARRIAGE _ 6:35

The main difference between crawler dozer

and loader undercarriages is the way they are eAtTrifir 7,
mounted. Crawler dozer undercarriages are
mounted so that each track frame can move
up and down independent of the other. This
method of mounting permits maximum track
contact with the ground when the machine is
working on rough uneven terrain.
Figures 6.39 and 6-40 show dozer track
frames sitting on their tracks. The frames are 4c.

mounted separately on bearings at the ;,..i

diagonal braces. The weight of the front of the PINNED >-.

tractor rests on an equalizer bar. which in turn EQUALIZER

BAR
rests on the two track frames. The equalizer DI GONAL BRA E
bar pivots at its center allowing each track to
independently move up or down as the trac- (6-40)
tor's weight shifts white moving over rough. Courtesy of Caterpillar Tractor Co
uneven ground.
/EQU LIZER BAR

...-...a.L...../11111a_ _-,Mllur-_

Ia DIAGONAL BRACES

(6-39) Courtesy of Caterruliar Tractor Co

Crawler loaders. unlike crawler dozers, need

to be stable when operating. Thus the track
frames on loaders are mounted so that there
is no relative up and down movement of the
frames. Rigid bars (Figure 6-41) joining the
Solid Cross Bar
two track frames are bolted to the tractors
main frame and keep the two tracks on the
same plane,

(6.41) ,.,
Courtesy of Caterpillar Tractor Co

.: 328
6:36 TRACK MACHINE UNDERCARRIAGE

EXCAVATOR, SHOVEL AND

CRANE UNDERCARRIAGES
Excavator undercarriages (Figure 6-42) are
similar to those of dozer loaders. having the
basic sprocket. flanged rollers. track chain
and bolt-on shoes. Shovel and crane un-
dercarriages (Figure 6-43) differ in that they
have a drive ,umbler or bullwheel, straight
rollers. and shoes that are linked together to
form the track.
Excavators, shovels and cranes have a broad,
strong and rigid frame (the carbody. or truck
frame) necessary to support heavy upper
works which revolve 360' over the un-
dercarriage. The propel and steering
mechanisms, whether mechanical or
hydraulic. are housed within the carbody. Be-
cause of their greater weight and size. ex-
cavators. shovels and cranes move more
slowly than crawler loaders or dozers.
EXCAVATOR UNDERCARRIAGE

Major components of the undercarriage are: (6-42) CAT

1. Sox-beam roller frames.
2. Lifetimelubricated rollers. carriers. and idlers. Courtesy of Caterpillar Tractor Co
3. Sealed track (pin-and-bushing joints).
4. Hydraulic track motors.
5. Oil disc track brakes.
6. Box-section carbody.
7. hydraulic track adjusters.
8. Heavy-duty recoil springs.
9. Solton track shoes in several widths and
types.
10. Full-enclosed. triple.reduction final drives.
11 Internal swing gear.

329
 TRACK MACHINE UNDERCARRIAGE 6:37

CENTER GUDGEON
AND VERTICAL
HYDRAULIC
FINAL PROPEL SHAFT
STEERING COMPONENTS
DRIVE CRAWLER
GEAR ASSEMBLY
CASE CARBODY

":-

PROPEL
GEAR CASE
Courtesy of Harnistifeger Corporation POI

(6-43) SHOVEL UNDERCARRIAGE

UNDERCARRIAGE COMPONENTS
The undercarriage components shown in
Figure 6-44 are discussed below.

1. Front Idler
2 Carrier Roller
3. Recoil Cylinder
4. Final Drive Assembly
5 Track Chain Assembly
6. Track Roller
7. Track Roller Frame
8 Track Shoe
C rurleey of Tere* General Molars Corporation

IF;te 33o
6:38 TRACK MACHINE UNDERCARRIAGE

Track Frames
Track frames provide a housing onto which all
the other undercarriage components are
mounted. The frames are drilled and tapped or
have bolting strips to mount the various com
ponents. Track frames are usually made of
channel or box shaped steel (Figure 6-45). OPEN CHANNEL
BOX-SECTION SOLID STEEL
Box shaped is used on large machines as it is
more resistant to cracks and bends. Solid (6-45) CAT
steel is also used on some large machines. Courtesy ol Caterpillar Tractor Co

Dozers with oscillating (moving up and down) Some manufacturers attach the frame ahead
track frames require some way of keeping the of the sprocket centerline and they may or
frames in alignment. One way is to weld a may not use a diagonal brace. To further aid
diagonal brace to the inside face of the track frame alignment dozers have a guide roller or
frame. thus allowing the frame to be attached bar towards the front of the machine. The
to the rear of the tractor at two points along guide rollers in Figure 6-47 are located just
the sprocket centerline, points A and B in behind the equalizer bar.
Figure 6.46.

DIAGONAL BRACE
A

SPROCKET
SHAFT-0.
(PIVOT SHAFT)
WI nil IlDiLiTKR PAIN
1.111-11 iff in 111- ni ire II

din !Vr_tc11.t iii1011110 filn111141 Arm

(6-46)

PIVOT BALL DIAGONAL BRACE GUIDE PLATE

rrN1/41
, !I
I 1

11

-1111 EQUALIZER BAR PIVOT

GUIDE ROLLER OR BAR

(6-47) CourlesY ol International Harvester

ftk...,A,
 TRACK MACHINE UNDERCARRIAGE 6:39

Recoil Mechanism and Hydraulic

Track Adjuster
The recoil mechanism located within each
track frame is either a large coil spring(s). a
gas charged cylinder. or a slack of conical
discs The purpose of the recoil mechanism is
to:
Act as a shock absorber for lorces
striking the front of the track.
Provide some give for the track if debris 1Spring. 2Spring. 3(Cavity 4Pilot.
gets caught in the sprockets or chain 5 Bolt 6 Piston 7 -Rod
links, or if material builds up in the (6 -49) RECOIL SPRING AND HYDRAULIC
sprocket teeth. TRACK ADJUSTER

On machines using springs as a recoil The hydraulic track adjuster (Figure 6-49) con-
mechanism the springs are compressed to a sists of a piston (6) installed in a cylinder.
specific length Then they are held by a Grease is forced into the cavity (3) to push the
through-bolt and positioned between stops recoil rod. yoke and idler outward to tighten
welded or bolted to the track frame. Recoil the track. Venting the cavity will slacken the
springs on some crawlers are submersed in track. Figure 6-50 shows a more detailed view
oil within the frame. of a hydraulic track adjuster cylinder.
integrated with the recoil mechanism is a Caution: the adjuster cylinder is under high
hydraulic track adjuster. a device that pressure. Therefore. venting the
tightens or slackens the tracks. Many track cylinder to slacken the track must
adjusters are located between the recoil be done with care.
spring and the front idler (Figure 6-43). The
adjuster may be part of the recoil rod or it may
be fitted into the front spring seat to act
against the recoil rod. Other track adjusters
are positioned within the springs (Figure 6-
49).

173134

(6-50) HYDRAULIC TRACK ADJUSTER CYLINDER

1Cytonder 2Fill valve. 3Relief valve
4Washer. 5Packing. 6Pislon.
7Rings. 8Snap ring
RECOIL RC.)

RECOIL MECHANISM

HYDRAULIC TRACK ADJUSTER FRONT IDLER

YOKE '

(6-48)

.332
6:40 TRACK MACHINE UNDERCARRIAGE

Note that although most modern machines Front Idler

use a hydraulic track adjuster. some older or
smaller machines will have a mechanical The front idler (Figure 6.52) is a large wheel
(threaded rod) track adjustment. attached to the front of the track frame. Idlers
are mounted on bushings or anti-friction
Some machines. Terex for instance. use a gas bearings, sealed (on most modern machines)
charged recoil mechanism and hydraulic by metallic face seals. and permanently
track adjuster combined (Figure 6-51). This lubricated on assembly. The idler both sup-
system works opposite to the hydraulic ad- ports the track and guides it into position for
juster in Figure 6-49. Grease is added to a the track rollers. The links of the track chain
cavity to slacken the track and exhausted to ride on induction hardened surfaces on the
tighten the track. outer circumference of the idler. Most idlers
are constructed of a steel drum casting.

7 8 13

=
14e.--IIIL

1941:41re-0-11- =
18
_ 7-7
16 15

(6-51)
LINKS RIDE HERE

1. Poston Rod
2 Giant Grease Fitting
3. Rod Guide
4. Bearing
5. "0" Ring
6. Backup Ring
7. "0" Ring
8. Retainer Plate INTERNAL
9. Screw GUSSETS
10. Bushing
11. Backup Rings
12. "0" Ring
13. Nut
14. Charging Valve
15. Piston
16. "0" Ring
17. Cylinder
18. Bleed Valve CENTER FLANGE
19. Seal
(6-52) FRONT IDLER

CourtesY 0 Terex General Motors Corporation

*.
artCr. 3.3J
 TRACK MACHINE UNDERCARRIAGE 6:41

Some tractors have idlers which can oe ad- Sprockets

justed to provide either a high or low position
(Figure 6-52). When the idlers are in high Sprockets are a large toothed wheel (of ap-
position there is less track-to-ground contact proximately the same 0.0. as the front idler)
area. and the tractor is more maneuverable. located at the rear of the track frame. At-
Turning is easier there is less wear on the tached to the final drive unit, the sprocket
tracks. With the idlers in low position there is drives the track chain by using the bushings
a greater length of track contacting the in the chain as leverage points.
ground and greater stability when the tractor Sprockets are made of forged or cast steel.
is equipped with heavy, front-mounted equip- heat treated and tempered for long life.
ment The drawback of the low position is that Sprocket teeth are machined to close toleran-
the increased ground contact causes more ces in a pattern called the hunting tooth
strain In turning and therefore more wear on design. The hunting design has an odd num-
the tracks. ber of teeth spaced in such a way that each
The general rule-of-thumb for idler adjustment tooth contacts a chain bushing only once in
has been high position for drawbar work and two revolutions. thus essentially doubling the
low position for bulldozer work or for use with life of the sprocket. Four common sprocket
heavy front mounted equipment. However a designs are shown in Figure 6-53.
better rule would be. that for maximum track
service life idlers should be adjusted to the
high position except where the low position is
necessary for machine stability.

(6-53)
SPOKE SPROCKET

Courtesy of Caterpillar Tractor Co

III 111111

IDLER IN HIGH POSITION

SHADED AREA REPRESENTS

GROUND CONTACT

IDLER IN LOW POSITION

(6-52)

Courtesy of Caterpillar TraCtor Co

on
4 ' 0.r 1.
r

r, ii;
334
. fj V
6:42 TRACK MACHINE UNDERCARRIAGE

(6-53) RING SPROCKET

(6-53) Courtesy of Terex
SEGMENTED OR BOLT-ON SPROCKET General Motors Corporation
16-53) DISC SPROCKET
Courtesy of Caterpillar Tractor Co

Spoke sprockets were generally used on older

machines although a few are still found on
modern machines. The spoke design has
given way to the drive disc and bolt-on
segments which are easier, and thus cheaper,
to replace when worn. Disc sprockets are
usually found on smaller dozers and loaders
and on most excavators. Ring sprockets are
another common sprocket usually found on
larger machines. A ring sprocket is often used COARSE TAPERED
in conjunction with a planetary reduction gear SPLINES FROM THE
assembly. Drive tumblers are used on shovels FINAL DRIVE
and cranes. Having no track chain, the backs
of shovel and crane track shoes are shaped to
accept the lug of the tumbler as a leverage
point. (6-54) Courtesy of Internatson Harvester
Sprockets are mounted in different ways. One
of the most common methods is to have a
large tapered spline on the sprocket fitting
onto a matching spline extending from the
final drive (Figure 6-54). The sprocket is
press-fit and retained by a large nut. A por-
table hydraulic press is needed to remove and
to replace the sprocket.

Two other methods of mounting sprockets are

(1) the sprocket or sprocket segments are
bolted to a drive disc which is splined to the
final drive gear. and (2) the sprocket is bolted
to a final drive flange (Figure 6-55).

(6-55)

Courtesy of Massey-Ferguson Inc rily

335
 TRACK MACHINE UNDERCARRIAGE 6:43

Drive Sprockets and Tumblers Track Rollers

In place of a final drive and sprocket assem- Mounted to the bottom of the track frame by
bly many shovels and cranes have drive end brackets. the track rollers support the
sprockets, chains and drive tumblers (Figure machine and distribute its weight to the track
6-56) From the drive sprocket. power is trans- chain. The rollers run on the chain links.
mitted by a chain to another sprocket at the Figure 6-57 shows a track roller dropped to
drive end of the machine. This second the chain links. To lake this picture. the track
sprocket is connected to a drive tumbler has been slackened and the track frame
which drives the track. The drive chain runs in jacked u p.
the open and requires regular lubrication, and
adjustment to compensate for wear.

(6-56) Courtesy of Bucyrus-Erie Ca

-ft

'176:,
IA 1
Aft.
(t$1.

DRIVE TUMBLER
Ills Sprocket Is Behind DRIVE SPROCKET
The Tumbler)
SHOES (6-57) Courtesy of Massey Ferguson Inc
1" DRIVE CHAIN 1" SHIMS

;"'.
r7-7:744-i,\
41111.ii
Inn
117?;:u
,C*Z-

ti,17,
, . 1,#),

DRIVE END IDLER END

(6-56)

336
6:44 TRACK MACHINE UNDERCARRIAGE

Flanges aid in keeping the track on the rollers Oil is forced into this passage and into a
and thus in line. If the roller has outer flanges cavity between the roller shell and the
only. it is called a single flanged roller. if it bearings. With the roller in a horizontal
has both outer and Inner flanges. it is balled a position the oil is fed in with a special nozzle
double flanged roller. Figure 6-58 shows a screwed into the end of the shaft. As the oil
double flanged roller. enters. the vented nozzle allows air to escape.
Once filled to a point where oil comes out the
TRACK ROLLERS nozzle. a plug is inserted into the shaft to seal
it. The oil filled passage and cavity act as a
reservoir for the roller.
700.4011.'"'
Such a lubricated roller is referred to as
kA 404gre". lifetime lubricated. although it can be topped
up if required. Generally though, if a roller is
leaking. trouble is indicated and the roller
,should be removed and repaired. Individual
rollers can be removed without having to take
off the track frame. as is shown in Figure 6-
ti 57).

(6-58)
Courtesy of Caterpillar Tractor Co
6
1409 3
Crawler dozers. loaders. and excavators TRACK ROLLER LUBRICATION
usually have an equal number of rollers. 1- Shaft. 2-Metal floating ring seals. 3-Passage. 4-Plug.
starting with a double at the front of the 5-011 passage. a-Reservoirs. 7-Passage.
machine and ending with a single at the (6-59)
sprocket. If there is any variation in this pat- Courtesy of Caterpillar Tractor Company
tern it will occur at the front of the machine
because a single flange roller always comes
next to the sprocket. The number and size of Shovels and cranes generally use a different
track rollers will vary from machine to type of track roller. It has a solid center flange
machine.
which runs in a groove in the track (Figure 6-
60). However. if a shovel or crane is equipped
Track rollers for dozers. loaders and ex- with tractor-type tracks. it will use single and
cavators have a forged steel shell with double flange rollers like those used on
replaceable anti-friction bearings or bushings. dozers.
Most manufacturers favor the bushing be- SEAL
cause it has greater :oad carrying capacity. is
cheaper. and takes less space. The rollers
turn on a stationary shaft held by end caps
bolted to the tracx frame.
Rollers are sealed and lubricated on assem-
bly. Most manufacturers use a metal face seal
(floating ring seal). one pair on each side of
the roller. because it's the most durable type
of seal for the severe conditions under which
rollers perform. The shaft is drilled lengthwise
part way. and then cross drilled (Figure 6-59). (6.60) SHOVEL TRACK ROLLER
Courtesy of Bucyrus Erie Co.

'337
 TRACK MACHINE UNDERCARRIAGE 6:45

Carrier Rollers Toric seal ring.

Metal floating wig seal. Outer Bearing.
2
3 Inner Searing. 4
The carrier rollers (Figure 6-61) support the 1

upper portion of the track between the

sprocket and the front idler. Carriers are
mounted to the top of the track frame with a
cantilever-type support bracket. There may be
one or two carrier rollers depending on the
size of the machine. Carrier rollers are made
of a forged steel shell similar to that of track
rollers. but have only a center flange.
0 ring

6 7 8 9
End collar Seal support. 0-ring. End cover.
(6-61) CARRIER ROLLER CROSS-SECTION
Courtesy 0 Caterpillar Tractor Co

The roller is mounted on two tapered roller

(6-61) bearings. pressed on the stationary shaft and
Courtesy of Caieroillar Tractor Co adjusted for preload by a nut on the end of the
shalt. A pair of metal face seals is used on
one end of the roller. while the other end is
sealed by a cover bolted to the roller shell.
Removing this plate gives access to the ad-
justing nut.
Similar to track rollers. carrier rollers are
lubricated on assembly with a vented nozzle.
Carriers. too. are referred to as lifetime
lubricated.

TRACKS
Tractor tracks are made of a chain with shoes
bolted to it. The continuous chain (with the
master pin inserted) travels an elliptical route
from the sprocket, over the carrier roller(s),
around the front idler. under the track rollers
and back around the sprocket. providing a
running surface for the machine to travel on
(Figure 6-62).

(6-62) 41PP
-7041111piir
Courtesy of Caterpillar Tractor CO

V 338
6:46 TRACK MACHINE UNDERCARRIAGE

Track Chains Track chain seals are two conical washers in-
stalled back to back in the link counter bore.
Track chains for a crawler dozer. loader and The seals are compressed. one against the
excavator are virtually the same. differing link counter bore. the other against the
mainly in their size A track chain consists of bushing end. as shown in Figure 6-63. When
two rows of links pined together by pins and the chain bends. the two seal washers turn
bushings. The pins and bushings have a against one another forming a seal.
clearance fit with one another. but are press-
fit into the links (Figure 6-62). The track chain just described is called a
sealed track and is common among many
The links are drilled on the top surface to ac- manufacturers. The latest development in
cept the shoe and are flat on the bottom lo tracks from the Caterpillar Tractor Company
provide a running surface for the track rollers. is the sealed and lubricated track.
The links are paired left and right and in-
terlock with one another. One end of the link
has a large hole to fit the bushing (with pin in-
side) and the other end has both a counter
bore to fit the bushing and seals. and a
smaller hole to accept the part of the pin ex-
tending beyond the bushing. Since the pins
and bushings are slightly oversized in relation
to the link bores. they must be pressfit into
the bores. This press-fit both holds the chain
together and allows it to be flexible. i.e..
hinge.

....:- .

(6-62) TRACK CHAIN LINK SEALS SEALS NOT COMPRESSED SEALS COMPRESSED
Courtesy 01 Caterpillar Tractor Co
(6-63)
Courtesy of Caterpillar Tractor Co

SHOE
BOLT HOLES

BUSHING
SEALS
RUNNING SURFACE
PIN LINK

COUNTER BORE

(6-62) SEALED TRACK CHAIN

330
0
9,..
 TRACK MACHINE UNDERCARRIAGE 6:47

The sealed and lubricated track (Figure 6-64) identified by the way it is retained. e.g.. a snap
uses the same link-pin-bushing arrangement ring. lock pin or machined step on one side of
as the sealed track. but the pins are lubricated the pin. The master bushing. too. differs from
and the seals are more positive (i.e.. they give the other bushings in that it is shorter to per-
a more complete sealing action). mit joining the track.
SEAL ASSEMBLY Figure 6-65 shows a master pin being in-
stalled. Note on this particular pin the
machined flat and the matching hole in the
master link.

.44),.. PLUG &

.t.; -, STOPPER

CROSS ,)0
HOLE
ffrl.
THRUST RING s ''
T$4347
(6.641
(6-65) INSTALLING MASTER PIN
Coonesy of Caterpillar Tractor Co (Track Shoes Removed for Better Illustration)
ALink. B-- Master pin. CMaster link.
Couriesv of Caterpillar Tractor Co
The pin IS the same size and length as before
but harder for added strength needed be-
cause of the hole drilled through its center.
This hole is the oil reservoir. A cross hole
provides a passage for oil to gravity feed to
the pin and bushing contact area. Alter the
seals are installed in the counter bore the
lubricant (90EP) is added and the passage
plugged with an expandable stopper. This
rubber material at me end of the pin is a visual
indicator of lubricated tracks.
The bushing is shorter than that of the sealed
track to allow room for the wider seal. The
ends of the bushing are lapped (smooth) for
the 'seal to ride Against. A two stepped
bushing is used on larger machines, thicker in
the center to give added strength.
Track chains, in general. are made to lengths
that fit specific machines. Chains will also
vary in the size of the link and in the pitch
length. the distance pin center to pin centei.
Pitch lengths will depend on the pitch of the
sprocket that drives the chain.
Tracks need to be coupled and uncoupled. A
master pin is the most common method of
separating tracks. The master pin is slightly
smaller than the other pins and can easily be

340
6:48 TRACK MACHINE UNDERCARRIAGE

Large Caterpillar machines are now using a Contact area (width of shoe)
master link (Figure 6-66) in place of a master Bending resistance
pin This master link simplifies removal and
installation in that the link has only to be un- Self-cleaning action
bolted to be disconnected The link saves Wear
time. and thus money. needed to service the
tracks Most machines have a standard shoe width.
but narrower and wider shoes are available.
The rule of thumb to follow regarding shoe
width is to use the narrowest shoe that
provides flotation and. at the same time.
allows full penetration of the grouser in
average conditions. The width of the shoe is

(6-66) * Rc54*
critical because the wider the shoe the
greater the load on the other undercarriage
Courtesy 0 Caterorliar Tractor Co components. This point is illustrated in Figure
6-67: two different sized shoes walk over a
Track Shoes rock on the outside of the shoes. The longer -
shoe has a greater lever arm, and therefore
Track shoes are bolted to the track chain The greater force is imposed on its roller flange.
shoes distribute the machines weight over
the broad surface area where the shoes con-
tact the ground. There are many different
types of track shoes. each suited to a par-
ticular machine. job and terrain.
It IS important that a crawler machine have the
right shoes for the job to assure maximum
track shoe life and minimum wear on the other
components. Terrain is probably the most im-
portant factor In selecting track shoes. Three
broad terrain conditions are dirt. rock. and ice
or snow A dozer will work on everything from
flat. soft soil to steep rocky slopes. A loader.
on the other hand. will generally work on level
compact matenal. Excavators and cranes
work in much the same conditions as loaders.
but they require a different type of shoe. The
excavator shoe is broad and flat (traction is
not a main concern) to give the heavy
machine good stability and flotation because
the upper works revolve 360 Other factors to
consider in selecting the correct shoe are:
Flotation
Traction
Penetration

S.
341
 TRACK MACHINE UNDERCARRIAGE 6:49

AFFECTED AREAS_.

(6.67) Courtesy of Tore* General Motors Corporation

Track shoes can be grouped Into two

categories'
I Grouser shoes (dozers. loaders. ex-
c avators)
2 Flat shoes (cranes, shovels)

Grouser Shoes
Grouser shoes are a flat steel plate with one
or more vertica: oars (grousers) that vary in
height end width. The purpose of the grouser
is to penetrate the ground to give traction and
mobility. Figure 6.68 illustrates the heat treat-
ment in a single grouser shoe. The light area
is very hard while the darker area is softer.
The soft area is necessary to allow the shoe to
flex to prevent it from cracking.

(6-68)
Courtesy of Caterpillar Tractor Co , ... '

342
$ %.
6:50 TRACK MACHINE UNDERCARRIAGE

Types Of Grouser Shoes STANDARD

Standard Grouser GROUSER

The most widely used all-purpose shoe on the

market. Usually installed on machines as
original equipment.

Center Punched Shoe

Similar in design and heat treatment to stan- CENTER PUNCHED
dard shoes. SHOE
Center of plate is cut out to prevent packing
of snow (or mud) in sprockets.

Manganese (Current Tractor Style)

A severe duty shoe for use where shoes are
subjected to severe pounding and abrasive MANGANESE
(Current Tractor Style)
rock.
Made of manganese steel which work har-
dens to about Rockwell "C" 50. The harder
the shoe is used. the harder it gets.
Offset
Bolt holes offset right or left so that the tracks OFFSET
ride inside the scraper or dozer blade cut
reducing twisting and wear of undercarriage
components (Figure 6-70.
Used to advantage on all scraper push-
loading and bulldozer applications on larger
tractors.
Exceptionally wide offset shoes are available DOUBLE
on a made-to-order basis for use where ex- GROUSER
treme flotation is needed.
Double Or Triple Grouser Shoes Are
Genre Ily Used On Loaders And Excavators
Double Grouser
TRIPLE
Two low grousers for less grouser wear, less GROUSER
turning resistance and greater manoeuver-
ability.
Double grousers increase beam strength
making the shoe less vulnerable to breaking
and bending. (6-69)
Greater penetration than flat shoe for better
traction in occasional dirt work. Three grousers for beam strength. les4
chance of break's': or bending. particularly
Triple Grouser on hard surfaces.
Low grousers reduce penetration. reduce Center punched for self-cleaning in muddy
turning resistance. result in a high degree of conditions.
manoeuverability with minimum strain to un-
dercarriage components. An excellent all around 'Aloe for common soil
as well as hard, smooth surfaces.

a1; ::'.
3.43
 TRACK MACHINE UNDERCARRIAGE 6:51

Flat design for low penetration and "110

manoeuverability.
Extra thick plate withstands the roughest in-
dustrial abuse.

Besides grouser and flat shoes, a third kind of

shoe, a skeleton shoe with various detachable
fixtures, is also used on dozers, loaders and
STANDARD SHOE excavators, This shoe is mainly for severe ice
TRACKS RIDING or snow conditions.
ON RIDGE

SHOVEL AND CRANE TRACKS

Shovels and cranes use a very different kind
of track than crawler dozers and loaders.
Shovels don't have shoes bolted to a track
chain. Their track assembly consists of a num-
ber of identical shoes pinned together. as
OFFSET SHOE
seen in Figure 6 -72,
44.TRACKS RIDING
WITHIN BLADE CUT ''17:11q.11.6...-
(6-70)
Courtesy 0 Caterploar Tractor Co MC.;- 7 rS.-,..
:. ..1.4.":. ......,...
'r ....lit. :' f
40.,,
..."

Flat Shoes (For Dozers, Loaders, r 1. '4081

jr 7'..
and Excavators) . :e.
Flat shoes are a flat steel plate with no ver-
tical bars. They are made in various
thicknesses (i.e., t...rengths). Support. not trac-
tor. is the prime function of flat shoes. The use
of flat shoes is limited. generally confined to
Jonditions where minimum ground distur-
bance is required and traction is not
Courtesy of Bucyrus -Erie Co.
necessary.
The track is driven by a drive tumbler whose
Flat Shoe teeth fit into grooves in the backs of the
shoes, using these grooves as leverage
Flat gtouserless design has great resistance
points,
to wear.
Extra :hick plate is built to withstand bending
or .dreaking.
Flat design offers no penetration and thus has
least turning resistance of any of the rock
shoes.

Steel Mill Flat Shoe

Similar to standard flat shoe except that not-
ches for detachable Trousers have been STEEL MILL
eliminated to prevent shagging. FLAT SHOE

Stronger than notched flat shoe. Restis

breaking.
Designed for use in mills and industrial ap-
plication on flat surfaces. (6-71)

;
1, X 'to:'
%Is. *.
344
6:52 TRACK MACHINE UNDERCARRIAGE

Shovel and crane regular track shoes are flat

because these machines usually work on
level ground and don't require much traction.
"the shoes gain their strength through
thickness. Shovel and crane shoes can bend, . .0.
2... b.
crack or break when subjected to severe ser-
vice Figure 6-73 shows two shovel track pads
and pins. :

.a4;i411
(6-74) "TRACTOR TYPE" TRACKS
Courtesy of 8ucyrusErie Co.

SHOVEL AND CRANE SWING

ASSEMBLY
There are two methods used to support the
heavy upper works, the machinery deck, of a
shovel or crane and allow it to revolve 360°.
One method is to place a series of rollers,
referred to as house rollers. between the up-
(6-73)
Courtesy of BucyrusErie Co.
per deck and the truck frame on a circular
roller path. Figure 6-75 gives a view of the
in addition to the standard shovel track, a roller circle on the truck frame. Note the large
"tractor type- track (Figure 6-74) is also swing gear inside the circle.
available. This tractor shoe would be used on
a machine such as a log loader which
requires better traction than the flat shoe
would give.

.4ealillidtillik`").
,.. Ar.
-
-
.- 4-4
., -
'
..';'.. . ..1,15.,.___aaliak-

tis
4,ft
AR.

(6-75) Courtesy of EtucynosErie Co.

6
.t2

a.. 345
 TRACK MACHINE UNDERCARRIAGE 6:53

In addition to the house rollers, hook rollers

(Figure 6-76) are used to hold the upper works
in line and to prevent wear on the vertical
swing shaft and bushings. Hook rollers are a
tapered roller supported by brackets attached
to the upper deck. As shown in figure 6-77 ,
they run in a tapered groove in the swing cir-
cle just under the house roller path. Hook
rollers are adjustable to compensate for wear.
Note the adjusting shims on the hook roller in
Figure 6-78.

(6-76) Courtesy of BucyrusErie Co.

HOUSE ROLLER PATH

HOOK ROLLER PATH

."411
Xr..
C-

, .,
4,

-
(6-77) Courtesy of BucyrusErie Co.

SHIMS

(6-78) Courtesy of BucyrusErie Co.

346
6:54 TRACK MACHINE UNDERCARRIAGE

The other method used for support and swing

is a ball bearing circle. Many hydraulic ex-
cavators use this system. The ball bearing cir-
cle employs a large precision fit, anti-friction
tearing in place of house and hook rollers.
The outer race is bolted to the upper deck and
the inner race is attached to the swing gear.
Figure 6-79 shows an excavator truck frame
with a ball bearing swing. Figures 6-80 and 6-
81 give a closer view of the ball bearing cir-
c le.
rz.2.

4ad.. Lal_swalw

(6-79)

Courtesy of Bucyrus-Erie Co.

Ash.
Large diameter swing circles are fully en-
closed anti-friction ball bearings. They
are sealed to exclude dust and other
foreign material
(6-80)
Courtesy of BucyrusErie Co.

(6.81)
Courtesy of BucyrusErie Co.

347
 TRACK MACHINE UNDERCARRIAGE 6:55

UNDERCARRIAGE GUIDES
AND GUARDS
Track guides and guards (Figure 6-82)
generally apply to crawler dozers and loaders.

End Track Guiding Guards assure track

alignment and extended life by preventing
4
track jumping the sprockets or scuffing the
rollers during turns and severe sidehill work.
They are attached to the track frame at the
front and rear.

Center Track Guiding Guards help keep

tracks aligned on rollers and prevent track
lumping Guards allow mud and snow to fall
free of the undercarriage, reducing packing
effect.
./

Track Roller Guards extend undercarriage

life by helping keep rock away from the
rollers. pins and bushings. They also help
keep the track aligned, reducing un-
dercarriage wear. The guards bolt on each
track roller frame inside and out.

Guards are also available to protect the

sprocket from large debris and sometimes
even the idler will be equipped with a guard
(Figure 6-83).

(6-82)
Courtesy of Caterpillar Tractor Co

(6-83' TYPICAL SPROCKET OR

IDLER GUARD
Courtesy of Terex. General Motors Corporation

348
6:56 TRACK MACHINE UNDERCARRIAGE

QUESTIONS TRACK MACHINE

UNDERCARRIAGES
1 On a crawler dozer or loader the term un-
dercarriage refers to three main groups
of parts What are they?
2 Briefly explain the main difference be-
tween a crawler dozer and a crawler
loader undercarriage.
3. What is the purpose of the track frame?
4 List two methods used to keep track
frames aligned.
5. Where is the recoil mechanism located
on the track frame? Briefly explain its
purpose
6. Where is the track adjuster located?
What are three common types of track
adjusters?
7 What is the best rule to follow regarding
idler position (high or low)?
8 What is the purpose of sprockets? List
four common types.
9 Where are the track rollers located and
what is their purpose? Explain briefly the
term single and double flanged.
10 Why do track rollers generally use
bushing or plain bearings rather than
anti-friction bearings?
11 Where are the carrier or idler rollers
mounted and what is their purpose?
12. Explain the difference between a crawler
track and a crawler shovel track.
13 What does the term pitch length refer to
on a track chain/
14 Give two methods used lo couple or un-
couple dozer or loader tracks.
15 What is the main difference between a
dozer track shoe and a shovel track
shoe?
16 What type of track shoe is generally
found on a hydraulic excavator.
17 Why is width important in a shoe?
18. Briefly explain the location of house and
hook rollers on shovels and cranes. How
does this system differ from the system
used on most current excavators?
19 What is the function of track roller
guards?

349
 TRACK NW-NINE UNDERCARRIAGE 6:57

UNDERCARRIAGE MAINTENANCE From the owners point of view. maintenance is

AND REPAIR often neglected for other considerations. On
one hand. they may have the best intentions of
MAINTENANCE AND SERVICE LIFE keeping their machines well maintained. but
on the other hand. they want to keep the
When a machine is purchased. it is thought to machine working and earning money. These
have a certain life expectancy. The main fac- two desires are often in conflict. and it's
tor that will determine d the machine reaches
frequently maintenance that takes second
its life expectancy. or goes beyond it. is main-
place as it's hard to work on a truck when its
tenance. For one thing is clear: if a machine rolling down the highway. The two main
receives no maintenance. it win be in the questic.ns that owners must ask in deciding on
scrapyard long before its projected life span how much maintenance to have done are:
is up
1 How long do they want the machine to
Inspite of its importance. maintenance is often last?
overlooked both by mechanics and machine
owners Maintenance is often neglected by 2. How reliable do they want the machine to
mechanics because it is held in low regard. be?
Maintenance. the thini,,ng goes. is dull. or-
dinary stuff. it lacks the glamour of It is a proven fact that service life and
troubleshooting a failure. an ability that is reliability are directly related to the care and
supposed to set the average mechanic apart frequency of maintenance.
from the expert. Yet. if you think about it. what
maintenance really is is troubleshooting a
machine before the trouble has actually oc-
curred. surely a job as demanding and com-
plicated as trouble shooting a failure. Good
maintenance practices take a lot of thought
and planning. besides regularity in carrying
them out.
Good maintenance is more than doing the
kinds of things that mechanics have been
conditioned to think of as maintenance. such
as changing oil. changing filters. greasing. In
general. these areas are maintained fairly
well. and are rarely the cause of shortening a
machine's life span What is more likely to be
the cause is a worn belt. a busted hose. a
neglected leak. an ignored worn part the
simple little things that no one thinks are im-
portant. Take the lower rad hose. for example.
Many would think 0 a pretty insignificant part
of the engine. not worth much attention in
comparison. say. to some parts of the fuel
system But consider what happens if these
two parts fail: if the fuel part fails the engine
stops or won't start If the lower rad hose fails.
in 30 seconds you've got a burned out engine.
a worthless block of iron. Now which is more
important?
This manual attempts. wherever possible. to
point out these "little- maintenance checks
that are so important to the service life of
machines. The checks are usually given in the
Daily. Routine Maintenance sections.

I
350
6:58 TRACK MACHINE UNDERCARRIAGE

DAILY ROUTINE MAINTENANCE

CHECKS ON UNDERCARRIAGES
Although the undercarriage accounts for only
about 20% of the purchase price of a track
machine. it accounts for about 50% of the
total maintenance cost of the machine. Since
the undercarriage takes such a large prop
don of total maintenance cost. many own s
stress care and preventive maintenance of
their machine's undercarriages, At the same
time, though. it should be pointed out that
other owners, for various reasons. run their
undercarriages to destruction and then outfit
the track frames with completely new com-
ponents. One case where an undercarriage
may be run to destruction is on a machine
working In sand. The sand wears parts so
rapidly that it may not be economical to repair
them. This manual assumes that un-
dercarriages are serviced by a good preven-
tive maintenance program.
The main purpose of maintenance checks is
to spot potential problems and repair them
before ma* damage is done. Good preven-
tive maintenance is being observant.
Each manufacturer supplies an operator's
manual for his machine. This manual is the
best source of information on daily. routine
maintenance checks. The maintenance
checks will be divided into time sections such
as daily. weekly .... or 10 hour. 50 hours ....
Fleet owners and large companies often make
up their own preventive maintenance check
sheets for their mechanics to use. Following
are examples of a shift maintenance sheet for
a shovel (checks applying to the un-
dercarriage are circled). and a weekly main-
tenance sheet for a shovel (only un-
dercarriage checks are included).

l'i 1. 351
.to. .,`
 TRACK MACHINE UNDERCARRIAGE 6:59
AFTON MINE, KAMLOOPS

DATE: MECH:.

1900 AL SHOVEL Hr. Reading: 301___ 302__ 303 301 302 303
Dipper teeth. caps pins

Side cutters. keepers

Adapters. "C"-Clamps. wedges

Bail pins. equalizer pins. sheaves. keepers

Stick/bucket pins. pitch brace pins and keepers

Trip cable. chain latch assembly

Snubber brake assembly

General wear condition

1

Track pads. pins keepers LH RH

Sprockets. idlers. lower roller assembly LH RH

Propel gearcase bolts. clutch & brake assembly LH RH

Lower tube system

Hoist ropes. lubrication. condition

Auxiliary copressor Drain moisture. check belts

Swing & crowd rotor blowers

Generator bearings

Magnetorque lubrication

Drain lube station moisture trips. top up oil as required

Check grease & gear cover tanks
tttt

Shipper shaft side play

Saddle block adjustment

Gantry & boom pins. keepers

Ladders & handrails

COMMENTS/PARTS USED'

2
 6:60 TRACK MACHINE UNDERCARRIAGE

GIBRALTAR MINES

WEEKLY MECHANICAL PM FOR PH 21008 SHOVELS

DATE UNIT NO. . . HOURMETER READING

...
TRUCK FRAME CHECKED BY- .
I CIRCLE ROLLERS WEAR-CHECK PINS AND SPACERS FOR WEAR .
2 RAILS UPPER . . . ...... . . LOWER .
3 CIRCLE TEETH WEAR . . .......... ..... ... ..
4 CHECK SWING PINION WEAR AND NUTS. LOCKS' LH. .. .. .. .. . . , RH .. ..... .. .
CHECK PROPEL BRAKE ADJUSTMENT. BAND & DRUM BRAKE RELEASED SPRING MEASUREMENT 171/e
6 CHECK HYD LINES FOR LEAKS AND DAMAGE. CHECK SOLENOIDS AND PRESS. 600 LBS. .
7 CHECK CENTER GEAR CASE FOR LEAKS OR DAMAGE
8 CHECK TRANSFER CASE FOR LEAKS AND DAMAGE ... ... . . . .
9 CHECK PROPEL GEAR CASES FOR LEAKS OR DAMAGE- LH . .... RH.. .
10 CHECK TRAIL CABLES AND SUPPORT FOR DAMAGE- . ..
SIDEFRAMES CHECKED BY. . ..
I CHECK TRACK PAD ADJ . PINS AND LOCKS. LH. RH. .

2 ADJUSTING SHIMS. LOCK BARS- LH . ... . . . . .. . . . RH . .

3 CHECK LOWER ROLLERS. SHAFTS LOCK COLLARS FOR DAMAGE LH . . RH .

...... . ...
.

4 CHECK IDLERS FOR WEAR. LH .. . .RH . . .

5 CHECK SPROCKET-LUGS FOR WEAR LH. . . . RH.

"- 353
-,
...b '
 TRACK MACHINE UNDERCARRIAGE 6:61

Daily. routine maintenance checks on track

machine undercarriages are much the same
for all crawler machines. Walk around and
check the machines general condition:
1. Inspect the tracks for broken or missing
shoes. loose bolts and any signs of
misalignment. Check for proper track ten-
sion (discussion following). Track tension
and shoe bolts of new tracks should be
checked every 10 hours. until the tracks
are broken in and the bolts have set.
2. Inspect the Qcrockets for wear.
3. Inspect the rollers and idlers for wear. (6-83)
leaks and damage. Courtesy of Caterpillar Tractor Co

4. Inspectthe guards and covers for Loose tracks (Figure 6.84) will not stay
damage. and for loose or missing bolts. aligned. accelerating wear on the idler and
roller flanges. At high speeds a loose track
5. On shovel tracks. check the track pins will slip and damage the links, idler and roller
and keepers and the track tension. flanges. On a side hill or in adverse conditions
Any minor problems should be repaired and loose tracks have a tendency to jump off. A
major problems reported. loose track is also hard on the sprocket. In
reverse the track will bunch up at the back of
Also note that track undercarriages should be the sprocket (Figure 6-85). causing sprocket
cleared ol debris at the end of the day. a job jumping which puts extreme stress on the
usually done by the operator. This cleaning is teeth.
particularly important if the weather is cold
and if the machine is working in mud or in
material that compacts. Left overnight. the
debris could freeze solid in the tracks.
TRACK TENSION:
DOZER% LOADER% EXCAVATORS
Track tension is the most important running 4
adjustment to be matritained on any track
machine. There are several reasons why
tracks require frequent adjustment. One is TOO LOOSE
that material. such as clay. builds up on the (6 -84) LOOSE TRACKS
sprockets and track chain, and the track must Courtesy of Caterpillar Tractor Co
be adjusted to make allowance for it. Another
reason is that the track stretches due to wear
on the pins and bushings. Track stretch is
discussed in detail later.
Tight tracks (Figure 6.83) accelerate wear on
all undercarriage parts pins and oushings. V. I
links. sprockets. rollers. idlers and reduce 6.
the tractor's horsepower because of in
-1,1!
.4

creased friction. OPERATING

IN REVERSE ;
WITH A . -
LOOSE TRACK

Note the bunching up of the

track here. ( PL.
_

(6.85) ';1,1e,Fa".M.

Courtesy of Caterpillar Tractor Co

I +: 354
6:62 TRACK MACHINE UNDERCARRIAGE

Tracks with correct tension will have some

slack to allow for working material build up
(Figure 6-85). The most common method of
determining if a track has the correct amount
of slack is to measure the sag midway be-
tween the idler and the first carrier roller. as is
illustrated in Figure 6-86. At mid point be-
tween the two the track should sag Ile (38
mm) to 2" (50 mm). If the amount of sag is not
right, the track has to be loosened or
tightened until the correct sag is obtained.

When the track is fully tightened measure

back half an inch from the idler
bearing support and mark.
(6-87)
Courtesy of Caterpillar Tractor Co

CORRECT

(6.85) i1:--
Counesy of Caterpillar Tractor Co aLr-".-1 -
[

(6.86) Tighten track so the idler bearing support

Courtesy of Caterpillar Tractor Co
is at the mark.
(6-88)
Courtesy o Caterpillar Tractor Co
Inaddition to measuring the sag. another
method in determining the correct track ten- Slackening and Tightening Tracks
sion has recently been recommended by the
Caterpillar Tractor Co. This method involves To slacken the track, pressure in the track ad-
measuring .'re .dler movement. The track is juster must be released. As was mentioned
fully tightened and a mark is made on the earlier most modern machines will have
track frame /2" (13 mm) behind the idler hydraulic track adjusters. However, some
bearing supp. 't (Figure 6.87). The track Is machines such as Terex use a combined gas
slackened so the idler bearing support goes charged recoil mechanism and hydraulic
beyond the mark. and then tightened again so track adjuster that works opposite to the
the support is at the mark (Figure 6.88). straight hydraulic track adjuster. As well,
some smaller or older equipment may use a
threaded adjuster. To slacken the track on a
particular machine, follow the procedures in
the service manual or read the instruction
decal conveniently located in the opening in

355
 TRACK MACHINE UNDERCARRIAGE 6:63

the track frame where the adjuster vent is loar

found. Do not attempt to slacken a track
without first reading the instructions.
On hydraulic track adjusters, grease is added
through a fill valve (Figure 6-89) to move the
idler forward and tighten the tracks. To loosen
the track the relief valve is turned allowing I -.2m=1=11

grease to escape. As the grease escapes.

pressure on the idler is released and it
retracts, slackening the track. Figure 6-90
shows the relief valve being turned. On a gas
charged recoil cylinder and track adjuster the
opposite procedure is used: grease is vented
to tighten the track and added to slacken it.

(6-90) OPEN THE HYDRAULIC RELIEF VALVE

.1. Courtesy of Caterpillar Tractor Co

Safety Precautions With Track Adjusters

1. When the track adjuster is extended to its
limit and the track is severely worn, it is
possible to remove the master pin without
venting the adjuster. Don't do it. Always
vent the cylinder no matter how slack the
track is because there can still be high
(Le.. dangerous) pressure within the ad-
juster cylinder.
2. When exhausting the pressure, keep your
face away from the vent hole, and as an
(6-89) added precaution cover the vent with a
Courtesy of Caterpillar Tractor Co rag. If you wish to see if grease is
escaping look at the cylinder to see if the
piston rod is moving to the rear toward the
recoil spring or look at the track to see if it
has loosened.

RELIEF VALVE AND FILL VALVE

(Later Machines)
1Relief valve 2Vent hole. 4Fill valve.
(6-89)
Courtesy of Caterpillar Tractor Co

356
 6:64 TRACK MACHINE UNDERCARRIAGE

3. To ensure complete retraction of the TRACK TENSION:

hydraulic adjuster piston. SHOVELS, CRANES
place a large piece of wood or a track Correct tension oli shovel or crane tracks can
pin in the sprocket {Figure 6-90 be set by a similar sag method described for
turn the vent screw one turn counter dozers and loaders. In Figure 6-92 a one inch
clockwise sag is recommended for both the drive chain
and tracks. Note that on shovels or cranes
back the machine up having me, Nical chain drives, the drive
The hack will then be completely slackened. chain as we. as the tracks must have the
To remove the block of wood. move th9 correct tension. When adjusting to get the
machine toward. correct tensions always adjust the drive chain
first. The adjusting mechanisms are usually
two sets of shims as seen in Figure 6-92.
Shovels or cranes that have direct drive may
10: also have either a set of shims to adjust the
tracks or a track adjuster.
urritli IrCW1144n9

ti

(6-91)
Courtesy of Massey Ferguson Inc

SHIMS TO ADJUST SHOES

SHIM RETAINER DRIVE CHAIN SHIMS TO ADJUST
1" 1
TRACKS

-
b( mos (1.0.C._ttg!!_(..). P oz=b- (:47111Iiiks
C;f'

#r9
1114

IDLER END
DRIVE END (6-92)

357
 TRACK MACHINE UNDERCARRIAGE 6:65

Tracks 01 large shovels with gear or hydraulic

drives are adjusted by shimming the idler tum-
bler as shown in Figure 6-93. When maximum
adjustment has been reached with the shims.
it is recommended that the track be broken
and one shoe removed. A hydraulic jack is
necessary to push the take-up shalt and tum-
bler assembly outward.

SHIMS (6)
SHIMS (A)

DRIVING

/
TUMBLER
wi-01-"WW.1r
'0I I WijitrIA ri 1,,,at
14Im 111111.._iii HYDRAULIC
40;k---.....-w-7._.\.. JACK

AIIIMIII.'

tlir
__.._
,
7/1....o....,
.......
-_,.....7_
_ ......_,,,
w,

.
-r &
.......... As,..

TAKE UP
SHAFT HYDRAULIC PUMP

2229

(6-93) ADJUSTING TRACK TENSION

Courtesy of Hornishfeger Corporalson. POI

301,
6:66 TRACK MACHINE UNDERCARRIAGE

GUESTIOta UNDERCARRIAGE
DAILY, ROUTINE MAINTENANCE
1. What is the best source of information for
the daily, routine maintenance checks
that Should be carried out on a machine?
2. Why are maintenance checks necessary?
List at least four things that should be
checked during a daily walk around in-
spection of the undercarriage.
3. What is a common method used to
measure track tension?
4. Briefly explain why correct track tension
is important.
5. On a hydraulic track adjuster grease is
added to ___ hie track and
to loosen it. On a gas-
charged combined recoil mechanism and
track adjuster grease is _____ to
slacken the track and vented to
it.
6. What precautions must be observed when
slackening a track equipped with a
hydraulic track adjuster?
7. Some shovels and canes have two
"chains" on each side. a drive chain and a
track chain. If both needed adjusting.
which one must be adjusted first? What is
the usual method of adjustment?

359
 f

TRACK MACHINE UNDERCARRIAGE 6:67

SCHEDULED MAINTENANCE As was stated earlier. the undercarriage ac-

counts for a large percentage of the cost of
UNDERCARRIAGE WEAR maintaining a track machine. Knowing this.
trictor companies have track specialists who
Track rollers. idlers. carrier rollers. sprockets travel around the province doing un-
and track chains (links. pins and bushings) dercarriage inspections "free of charge" with
wear out like tires on trucks and eventually the intention. of course. of selling service.
have to be replaced.
The point of a good preventive maintenance Before looking at the methods of measuring
program is to maintair. the undercarriage so the wear and alignment of unde.carriage
that these components all wear out at ap- components. the subject of why and how a
proximately the same time. This is called component wears will be discussed.
matching wear on components. Matching
wear is not always possible because various PIN AND BUSHING WEAR
stress factors can cause one component to
Tracks are subjected to the severest wear of
wear faster than another. Some of these fac-
tors are: any of the undercarriage components and if
not maintained they can cause accelerated
Environment - Rocky terrain obviously wear to the other components.
causes more wear than soft earth. Sand and
Other gritty materials act as abrasives and can The sealed track (as opposed to the sealed
cause rapid wear and lubricated OW tuns dry with metal to
meta. contact. causing wear to the pins.
Type of Work The heaviness of the work in- bushings and links (Figure 6-94). External
volved: steep grades side hills. all will affect wear occurs to the bushing on the outer sur-
wear face area contacted by the sprocket tooth. an
Operator Operators have different working area amounting to about 1/3 of the bushing
and maintenance habits which will affect circumference Internal wear occurs to the pin
wear Some operators are much harder on and inside of the bushings and to the end of
machines than others the bushing where it fits into the link counter
bore (Figure 6.95).
Speed The faster a machir4 goes the
harder it is on the undercarriage.
TRACK ROTATION

NEW LINK
PIN
ASSEMBLY JOINT
BUSHING
PRESS Fit BUSHING WEARS PIN
(No movement between SPROCKET WEARS
link and bushingSr,.. BUSHINGS

PRESS FIT (6-94)

(No movement between Courtesy of John Deere Ltd
link and pins)
WORN LINK
ASSEMBLY JOINT
BUSHING WEAR PIN WEAR

BUSHING WEAR

4
CENTERLINE OF PIN 111- l oeCENTERLINE OF BUSHING
AMOUNT OF TRACK LENGTH
INCREASE PER LINK
(6-95) PIN AND BUSHING WEAR Courtesy of international Harvester

360
6:68 TRACK MACHINE UNDERCARRIAGE

As pins and bushings wear. the track pitch

(the distance from pin center to pin center) in-
creases and thus the track stretches (Figure
6-96). when the track is stretched. the track
pitch and the sprocket pitch no longer match.
Thus the bushing is picked up sooner by the
sprocket tooth. causing the wear line on the
tooth to rise (Figure 6-97). A raised wear line
on the drive side of sprocket teeth is a sure in-
dication of pin and hushing wear. when
bushings ride up on the teeth they also cause WORN PROFILE
rotating wear to the other side of the tooth as
the bushing exits the tooth. Figure 6-98 details
sprocket wear.

< >
Track s-t-re-t-ches
.0

(6-98) courtesy of Jotort Deere Lld

1 Drive Side Wear when operating

forward
WORN PINS AND BUSHINGS 2 Reverse Drive Side Wear when
operating in reverse.
(6-96)
Courtesy of International Harvester 3. Climbing Wear result of increased
track pitch
4 Root Wear when bushing SlideS
WEAR LINE WITH WORN PINS from side to side
AND BUSHINGS
-IR
ROTATION 5 Rotating Wear when bushing
rotates as it leaves (forward) or en-
ters (reverse) the sprocket
6 Reverse Drive Side Top Wear -
when sprocket pitch is greater than
track pitch

WEAR LINE WITH NEW PINS

AND BUSHINGS
Another damaging effect of worn pins and
bushings is a snakey track. The space created
X2663
by the wear between the pins and bushings
(6-97) WEAR LINES ON SPROCKET TEETH allows the track to cock. causing it to wander
IA ni tteiy of John Deere Ltd from side to side. or snake. A snakey track
leads to rapid wear on the links, idler. carrier
and track roller flanges. and track guiding
guards.
Track stretch can be compensated for by
tightening the track with the track adjuster.
Eventually though. the track adjuster will not
be able to tighten the tracks any further. and
the stretched track can only be corrected by
turning the pins and bushings 180. Turning
pins and bushings will be discussed later.

361
 TRACK MACHINE UNDERCARRIAGE 6:69

Undercarriage Wear On Sealed

and Lubricated Tracks
Lubricated tracks appear to reduce track and
undercarriage wear significantly. Track
stretch is virtually eliminated because there is
very little pin and bushing wear. The service-
life of sprockets, roller flanges, idlers and links
is increased because there is less stress on
them. Other advantages of lubricated tracks
include quieter machine operation. and
reduced friction which gives more efficient
use of engine horsepower. Lubricated tracks
are not the answer to all track and track
related problems. but reports on them to date
indicate an extended life of tracks and other
u ndercarri age components.

MEASURING UNDERCARRIAGE WEAR

An undercarriage component is measured
and recorded on a field check sheet. This
measurement is then looked up on a Per-
centage Worn Chart (usually accompanying
the field sheet) to find the percentage the
component is worn. Percentage worn chart
figures are calculated to a rebuild limit, i.e..
when a part is 100 percent worn. it is ready to
be rebuilt. If let go any longer the part may not
be economical to rebuild. Note that because a
part is beyond the rebuild limit (over 100%), it
is not necessarily worn out. The part may have
many hours of service left. Being over the
rebuild limit simply means that from a cost-
benefit point of view it is better to let the part
run out its service life than to rebuild it.
Following is an example of a field check sheet
and a percentage worn chart (courtesy of
Caterpillar Tractor Co.) Note that the chart is
given only as an example and should not be
used to calculate component wear because
the figures may be out of date.

362
,;(4,.. ,
6:70 TRACK MACHINE UNDERCARRIAGE

UNDERCARRIAGE FIELD INSPECTION REPDRT

ICUSTOMER MODEL
LOCATION 5/N SMR

DATE 110B No. REPORTED BY

INSPECTION CHECK LIST

LINKS LCIT rttUMT PINS & BUSHINGS SHOES tor
Height Pitch (4 sections) Grouser height
Port No.
Sections
Bushing 0.D.
Most wear:
I"" r"? I Grouser base width
Plot. thickness
Forward drive side Type:
Rebuildoble? Reverse drive side Standard
Crocks? ®1M Specie, application
Face weer? Sealed? Extreme service
Roil side wear? Turned? Other
Counterbore wear: Bushings cracked? Bolt bole size
Moderate Pins welded to links? % hardware reusable
Severe Missing shoes
KW CU
Regrou sered?
Bent shoes?
Loose .shoes?
-El
SPROCKETS I-o, tosekr IDLERS LeOPT I POIOIT CARRIER ROLLERS Ler? steamy
% worn Center flange height Treed diameter I
Most wears Flange condition Hong. condition
Forward drive side Internal coalition internal condition
Reverse drive side Spoke or disc?
Spoke or disc? 111711 ECM

Rebuildabie? Lifetime?
Rerliorned?
Lifetime? Rebuildoble? MEM
Anal drive leaks? Chipped?
Leeks?
Crocks?
Crocks?
Bolt on ? Reinforced?
TRAtZ ROLLERS SOURCE
Tread diameter Ls.? 1 mewl GENERAL torts reposentativa
Front Substitute parts Service department
Rear Track odjustment Machine salesman
Other Mechanical or hydraulic Mobile track press
Flange condition Tension spring condition Track Si roller shop
Inter/101 condition Alignment Used parts
Quantity; SF Frame cracks
DF Visible reinforcement
Condition of:
L if. time? Rock guard
Roby ihlable? Equalizer spring/bar
Leaks? Weer stripe & guides

Summary Percentage wens

SERVICEMAN MUST COMPLETE _

Dote Howe Links Pitch Bushing Shoes Sprockets Idler. C/Rollere T/Rollers Howe Call
___ Left Beck

--,,--
_.

PERCENTAGE WORN CHART APPEARS ON REVERSE

Courtesy of Caterpillar Tractor Co

363
 TRACK MACHINE UNDERCARRIAGE 6:71

UNDERCARRIAGE PERCENTAGE A. All MeaSurements are rn inches

WORN CHART 8. All % are precentage Worn figures
C. Pin & tustung - 17" scale used if abrasive condrtinna
consult .19' ' scale - CTS Handbook

For Additional Information Consult Your Custom Track Service Handbook

MODEL LINK PIN 6 BUSHING SHOES IDLER CARRIER TRACK ROLLERS

CK PITCH % 70926.20 BUSHING % O.D. cOrr.u00. it1.14.44C I
70244 % 404,64S % % "LLER % 444 440. % 72,172S.26., %
421927.26 essscs.z. PITCH 714104 2,42624 11,1927.26 t26,21.241

O 96 6.12 ' 0 5.69 0 41.04 0 3.37 0 3.44 0' 3.44 0 .88 0 0.62 t 0' 10.62 07. 10.62 0
10.2s- 4.00 27 5.60 25 41.15 23 3.34 25 2.80 26 2.90 28 .96 29 8.46 25 10.42 22 10.46 22
5.88 63 5.50 52 41.30 54 3.31 50 2.20 51 2.40 54 1.04 52 8.30 51 10.18 49 10.26 49
5.78 76 5.42 75 41.40 75 3.28 75 1.60 75 2.00 74 1.14 76 8.10 76 9.94 75 10.06 76
5.6 1.4 ii 11 LI 1.00 00 0 .. i.s . 100 9.62 100 9.87 OQ

09 t26 1 6 644264
240421.24 % 724444 % I 2 1426 % % Da / 423.24 %
9.03"
5.25 0 36.04 0 3.19 0 3.06 0 3.06 0 .90 0 8.432 0 lom 1 0
5.16 27 36.15 Z3 3.16 25 2.50 27 2.60 29 .96 29 8.46 25 10.46 23
5.06 51 36.30 54 3.13 50 2.00 51 233 49 1.04 52 8.30 51 10.26 52
5.00 75 36.40 75 3.10 75 1.50 76 1.90 74 1.14 76 6.10 76 10.10 75
4.90 100 38.52 100 3.07 100 1.00 100 1.93 100 1.24 100 7.87 100 9.93 103

De14983 lisle I.sz % e14es3.34 % % % nes., % swum % % % 769161.62 % 1240sss4 %

9.00" 0
!Oa Tliga*OtS
5.41 5.25 0 36.04 0 3.04 0 3.06 0 3.06 0 .94 0 7.50 0 10.00 0 10.00 0
5.30 24 5.16 . 23 36.15 23 3.01 25 2.60 22 2.70 23 1.02 28 7.34 2b 9.76 27 9.80 25
UK CIS 140.06Ca4
5.18 51 5.:: r 48 36.30 54 2.98 50 2.00 51 2.30 49 1.10 51 7.18 51 9.56 49 9.60 50
5.06 78 4.94 78 36.40 75 2.95 75 1.60 76 1.90 74 1.20 74 6.98 76 9.32 76 9.40 76
4.91 100 4.83 100 36.52 100 2.92 100 1.00 100 1.50 100 1.31 100 6.75 100 9.00 100 9.16 1100

De cosss.ss % 7is7e46011 % % % 746724 % w % % 1224S4.40 % 74,744444 %

e.00 4.97 0 4.80 31.98
0 0 2.75 0 2.81 0 2.81 0 .88 0 "..50 Or 9.06 0 9.06 0
4.88 27 4.82 1 23 32.10 25 2.72 26 2.34 28 2.48 27 .94 22 7.34 25 8.90 26 8.90 29
4.80 50 4.74 152 32.25 56 2.69 60 1.92 149 2.16 50 1.04 52 7.18 51 8.74 52 8.78 50
4.72 74 4.64 77 32.35 77 2.66 76 1.44 70 1.130 77 1.14 76 6.98 76 8.54 75 8.62 74
,ii 50 100 4.65 '100 32.46 100 2.63 100 100 00 1.50 100 1 24 ,00, 675 1001 8.31 100 8.40 100
D 7F 622S6f .90 % 20 74940 74 % % 140407 % oussso % % % sszsso.so % zsisssso %
5.50 10 0
remcrioc 146794
4.94 0 4 75 34.04 0 2.81 0 2.81 0 2.81 0 .88 0 7.50 8.75 0 8.75 0
xc CIS Oto. 4.84 25 4.66 , 27 34.16 23 2.78 25 2.34 26 2.46 27 .94 22 7.34 25 8.66 23 8.60 22
4.74 51 4.58 34.30 54 2.75 50 1.92 49 2.16 50 1.02 47 7 18 51 8.32 52 8.40 51
4.64 76 4.50 176 34.40 75 1.44 76 1.80 1.14 76 6.98 76 8.12 77 8.24 74
4.50 )0(1,
i SSSSS ss'
4.40
76
041, lija 75
1011
2.72
2.110 1404 J.01 1 1.50
77
100 1.24 )0(1. 6.75 100 7.87 160 8.06
12166244
100
D 7-977 IS I44S64 % % % 142766 54 7u7S2 % % % 1240,44 II
0.00" 4.53 0 0 2.62 0 2 81 0 2.81 0 .88 0 7.50 0 0.75 0
31.98
rmaimmocs
4.r.4 26 32.10 25 2.59 25 2.34 26 2.46 27 .94 22 7.34 25 8.56 26
sumo 6 'Sin* 4.46 49 32.25 56 2.56 50 1.92 49 2.16 50 t.1:1 52 7.18 51 8.36 53
xc cis 0.36 77 32.35 77 2.53 75 1.44 76 1.80 77 1.14 76 6.98 76 8.20 75
4.25 100 32.46 100 2.50 100 1.00 100 1.50 100 1.24 1001 6.75 1 8.00 100
710101.10
DISC
S.00"
4susesz % 94S321.2 % % % 427467 i % rsosss 96 % 11, :slziitsi: % OuS627.24 %
maims sr, 4.65 0 4.50 0' 31.98 0 2.62 0 2.38 0 2.38 0 .88 0 7.38 0 8.25 0 8.25 1 0
* IOU 4.56 25 4.44 ; 21 32.10 25 2.59 25 2.02 26 2.14 27 .94 30 7.22 25 8.06 26 8.10 25
MO CIS aatamegt 4.48 48 4.36 i 49 32.25 56 2.56 50 1.72 49 1.96 48 .99 49 7.06 51 7.90 40 7.94 53
4.30 76 4.20 177 32.35 77 2.53 75 1.38 74 1.72 77 1.06 77 6.86 76 7.70 75 7.82 73
4.27 J90 4.20 100 32.46 TOO 2.50 100 1.07 LSO 1.13 111* 6.63 100 7.59 100 7.66 030
% %
427661
% %
4, up IRMA in OS scum secs
1396.9611 21109.40 S WOO6S64 % 427644 Ss 6 77S . .. maisseocras Linsosocres
.
5.75" 4.00 0 3.91 0 26.98 0 2.17 0 2.12 0 .69 0 .78 9 6.75 0 8.00 0 8.00 1 0
3.92 24 3.08 21 27.10 25 2.09 25 1.80 26 .58 25 .84 30 6.84 24 7.88 23 7.84 24
3.84 49 3.78 53 27.25 58 2.06 60 1.48 52 .46 50 .90 57 6.52 49 7.72 55 7.64 53
3.76 73 3.70 75 27.35 77 2.03 75 1.20 74 .36 75 .96 77 6.40 75 7.60 75 7.48 77
3.66 100 3.61 10Q 27.41. 100_ 2.00 10 .68 100 .25 100. 1.03 ,100 6.25 100_ 7.41 100 7.32 100
sss.14 S I .440Mr0 74.440/144
WOW 14se,26142 -,0 % % S6424 64 TM
--., % % % roCas"a&Igua2 0:2°R;&:: / %
6:01" 4.03 0 27.67 0 2.31 0 2.25 0 1.00 0 .78 0 6.75 0 8.00 0 8.00 0
3.96 23 27.80 27 2.26 25 1.92 24 .00 26 .82 20 6.64 24 7.84 26 7.80 27
3.08 52 27.30 48 2.25 50 1.66 50 .84 47 AS 49 6.52 49 7.60 52 7.64 41
3.80 76 28.06 79 2.22 75 1.24 74 .44 74 .96 77 6.40 75 7.48 76 7.44 176
3.69 100 28.16 100 2.19 100 .68 1001 .24 100 1.03 100, 6.25 Al 7.26 100 'Ji_..26
100
_ 07'142 .f
04-941
0.76"
WHO- 24 .14
S64421.24
4 44444 44 % % % ...) 4776 % 4116444 % % S
201.1.CR
. Ws 4140 . 442 41212

swami sum sm.

X3.75'
5 ' 0 3.66 0 26.98 0 2.12 9 Les 0 .89 0 .68 0 5.88 0 8.00 0 8.00 0
res., w4m
3.69 24 3.50 24 27.10 25 2.09 7: 1.60 25 .58 25 .72 20 5.76 26 7.88 26 7.88 24
3.62 52 3.53 52 27.25 56 2.06 50 1.32 50 .48 52 .78 49 5.64 51 7.78 49 7.74 52
3.58 76 3.47 76 27.35 77 2.03 75 1.04 74 .38 75 .86 77 5.52 77 7.88 75 7.62 76
3.50 100 3.41 SOO 27.48 100 2.00 100 .75 100 .25 100. .93 100 5.38 100 7.50 100 7.50 100

Courtesy of Caterpillar Tractor Co

364
6:72 TRACK MACHINE UNDERCARRIAGE

Measuring Tools
Plastic track wear gauges (Figure 6-99) are
available for many machines. Gauges are not
always the most accurate measuring tool. but
they are handy and easy lto use. A ruler. depth 0
gauge. tape measure. and set of outside
calipers (Figure 6-100) will give reasonably foimpotisvie
accurate measurement of undercarriage com-
ponents in the field. (6-100)
38
6.4.1.7Of
1001,004
72" STEEL TAPE MEASURE
Courtesy 01 Caterpillar Tractor Co.

(6-99)
Courtesy of Caterpillar Tractor Co To perform a track measurement inspection,
move the machine to level, firm ground. clean
any accumulated material from around the
tracks. and do a walk around check. Before
measuring the tracks Check the top part of the
, bushing with your finger to make sure the pins
ipproirrir ,
and bushings have not already been turned.

External Rushing Wear

12" STEEL SCALE
Using outside calipers measure the bushings
(6-100) (Figure 6-101). Be sure to Jake the
measurement across the worn diameter of the
Courtesy of Caterpillar Tractor Co bushing. Measure three or four bushings in
different parts of the track to obtain an
average measurement.

BUSHINGS
(External

12" OUTSIDE CALIPERS

(6-100)
Courtesy of Caterpillar Tractor Co

0
(6-101)
(6-100) Ii
WIDE BASE DEPTH GAUGE
(Lufkin 509E depth gauge Shown here)
Courtesy of Caterpillar Tractor Co
365
 TRACK MACHINE UNDERCARRIAGE 6:73

Internal Pin and Bushing Wear Divide the measurement by four. the number
of links included. to get a figure for the
To take up the slack in the track. place a present track pitch. Look up this figure on the
block of wood or a steel pin in a sprocket wear chart to find the percentage the pitch is
tooth and then reverse the tractor. Measure worn. Note that some wear charts such as the
from the side of one pm to the same side of one shown give a four link measurement. and
the fifth pin away. This measurement will in- so it is not necessary to divide by four.
clude four links (Figure 6-102). The pins
measured should not be within two of the The same measurement procedure should be
master pin. and should be taken on a section repeated on the master track section to deter-
of the track that is not on the ground. mine whether the master pin and bushing
should be replaced. The master pin and
bushing always wear faster than the others
because there is a greater clearance between
them, necessary for breaking and connecting
the track. Of course. the second measurement
would not be applicable where a master link is
used rather than a master pin.
U the track pitch is not beyond wear limits and
if the bushings are not cracked. the pins and
bushing can be pressed out and turned 1130`..
Turning the pins and bushings will greatly ex-
tend track service life. Figures 6-103 and 6-
104 show the effects of rotating the pins and
bushings.
CENTERLINE OF SPROCKET PITCH

N./ lAk..CENTERLINE
OF WORN
TRACK PITCH

BEFORE TURNING
XVO9 (6-104)
CENTERLINE OF BOTH TRACK
AND SPROCKET PITCH
RE-ESTABLISHED

AFTER TURNING
(6-104)
Rotating Worn Pins and
Bushing 180 Degrees
excessive wear causes stretch between bushings; Courtesy 01 John Deere Lid
bushings then tide up on sprocket teeth

Cour leeY of Caterpillar Tractor Co

(6-103)

366
6:74 TRACK MACHINE UNDERCARRIAGE

It should be pointed out that not all machines number of hours before turning and after turn-
will have their pins and bushings turned. ing. For example. if by using method one you
Some abrasive working conditions wear parts have 800 hours before turning. 1100 hours af-
very quickly and make turning uneconomical. ter and 1900 hours total. the next time you
Also. some companies have a policy of sun- should try turning at 1000 hours You will
ning the undercarriage to destruction doing probably get 1000 hours after turning for a
little or no repair. total of 2000 plus hours.
The third method involves turning the Pins
and bushings at one half the expected link
life. Method three assumes that from past ex-
When To Turn Pins and Bushings perience you know what link life will be and
also assumes that the machine is working in
Correct timing of turning pins and bushings is similar conditions. This method will not
important.
usually work if link life exceeds pin and
bushing life by more than 50 percent.
WHEN DO YOU TURN PINS AND BUSHINGS?

Better late It's better tot Example Problems For Method Three:
than never. turn too early
'flan too") 1. Normal link life 3000 hours
Normal pin and bushing life
(without turning) 2000 hours
Solution: Turn at 1500 hours pins and
bushings should last 1500
hours after turning to give a
total of 3000 hours.
2. Normal link life 3000 hours
Normal pin and bushing life
(no turning) 1600 hours
i
Solution: In general replacing pins and
bushings at 1500 hours rather
than turning would be best.

WRONG!! RIGHT! 3. Normal link life 2400 hours

(6 -105) Normal pin and bushing life
(no turning) 2000 hours
There are three generally accepted methods Solution. Turn at 1200 hours pins and
for determining when to turn pins and bushings will easily make it
bushings. The first method consists of another 1200 hours.
keeping accurate measurements of track
stretch and consulting wear charts. as The advantage of this third method is that pin
discussed earlier. This method requires no and bushing life is matched to link life while
past experience of how long pins and track stretching is held to a minimum In the
bushings and links last. It is the most reliable last example.
of the three methods and is the only depend- 1. pin and bushing life is extended 400
able one for tractors working in various en- hours
vironments.
2. the links, pins and bushings can be ser-
The second method consists of making the viced at the same time.
number of service hours before turning equal
to the service hours after turning. Method two 3 the track never gets badly stretched
implies that you have past experience with the
machine in similar working conditions. that is. 4 sprocket life can be extended up to 100
you have applied method one and know the percent

367
 TRACK MACHINE UNDERCARRIAGE 6:75

Some owners question the cost of turning.

However. in most cases the expense is
Justified on a cost per hour basis. The
economics of turning can be figured in this
way' divide the initial cost of pins and
bushings by the number of hours they'll last if
run to destruction. Add together the initial
cost of pins and bushings and the cost of turn-
ing them. Divide this combined cost by the
total number of hours the customer will get by
turning. This will give you the cost per hour of
turning.
(6-106)
Also. from a cost standpoint. it cannot be Courtesy 01 Caterpillar Tractor Co
over-looked that running pins and bushings to
destruction increases wear on links. rollers.
idlers and particularly sprockets. The un- Link tread wear can be determined by com-
dercarriage works as a unit. Excessive wear paring the height of the worn links (Figure 6-
in one area. particularly pins and bushings. 107) with the height when new. If link
will cause accelerated wear on the other com- rebuilding is intended. check the worn chart
ponents. for the rebuild limit.

Link Wear
Links form the surface or rails that a machine
runs on. They are rugged parts that take a lot
of abuse especially if the tracks are allowed
to run loose. or if the machine is run at high
speed. Normal link wear is caused by the links
contacting the rollers and idlers.
Types of link wear are (Figure 6-106):
Rail tread wear
Rail side wear
Rail inside gouged
Pin boss worn
Bolt holes wallowed oul or elongated (6-107)
(shoes run loose)
Worn counter bore. Track Shoe Wear (Grouser Heighth)
Rest the crossbar of a depth gauge. or a steel
rule, across two grousers (Figure 6-108).
vieasure from the bottom of the crossbar o'
rule to the shoe plate to determine the grouser
height. Grouser wear is the difference be-
tween this height and the height when new.
RAIL
SIDE WEAR

WORN
COUNTER BORE

(6-106)
Courtesy 01 CaleMillar Tractor Co

'.
(6-108)
ass
6:76 TRACK MACHINE UNDERCARRIAGE

Shoes should nut be allowed to wear too much ll rock guards are installed roller diameter
if rebuilding is intended. As the grouser cannot be measured with a caliper. Here is an
wears. the shoe loses its beam strength and alternate method (Figure 6-110
will bend Also, once worn beyond the depth
of the hardening. the grouser will wear Measure vertically from the shoe to the center
rapidly Check the worn chart for the grouser of the roller shaft to get "B". Subtract link
rebuild limit height "C" to get roller radius "A ". Cocking or
tilting the shoe. or a bent shoe. will cause
Track Roller Wear inaccuracy. Take three or more
measurements and average them. Example: If
Roller diameter is calculated by calipering the the roller shaft center to shoe height. "B" is 9
roller tread (Figure 6- 109). The worn diameter. inches and rail height. "C" is 5 inches. then
when subtracted from the new roller diameter. roller radius. "A'S will be 4 inches. Taking this
gives the amount of surface tread wear. radius and doubling it will give the worn
Check the worn chart for the track roller diameter of the roller. 8 inches.
rebuild limit. Track roller wear is shown in
Figure 6-110. ROLLER RADIUS
(on machine with roller guards installed)
ROLLER DIAMETER

(6-1 11)

1.
R
A

Side hill operation caused this Contact ith link rails caused
roller flange wear. this roller tread wear ...
(6 -110)
Courtesy of Caterputfer Trocie Co

369
 TRACK MACHINE UNDERCARRIAGE 6:77

Idler and Carrier Roller Wear Sprocket Wear

Idler tread wear can be found by measuring Sprockets can be measured with a wear
the present height of the center flange and gauge (Figure 6-113). but generally a visual
comparing it with its height when new (Figure check of the sprocket for wear marks on the
6-112). Check the wear chart for the idler teeth will reveal how badly it is worn.
rebuild limit.
Carrier Roller tread wear can be found by
calipermg the tread surface and comparing it
with the tread surface when new. Check the
wear chart for Me carrier roller rebuild limit.

IDLER TREAD

rag.
s'474os °
t

(6-112)

:Eutaw/A
(T75449)
(6.113) CHECKING SPROCKET TPC:re WEAR
Courtesy of FiatAnn Construction
Machinery Ltd

370
 6:78 TRACK MACHINE UNDERCARRIAGE

Wear Gauges
Gauges for specific machines are available to
check the wear on various undercarriage
components (Figure 6-114). Wear gauges ap-
ply only to the machine they were made
they can't be used on others.

PIN AND BUSHING WEAR CARRIER ROLLER WEAR TRACK ROLLER WEAR

f. _

itiediro_n

(AK WEAR SHOE (GROUSER) WEAR DRIVE SPROCKET WEAR FRONT IDLER WEAR
AZ 558

(6-114) MEASURING TRACK WEAR WITH A SPECIAL WEAR GAUGE

Courtesy of John Deere Ltd

3n
,MIIMmob

TIVA:IC MACHINE UNDERCARRIAGE 6:79

ALIGPMENT Idler Alignment

Proper alignment of the roller frames and 4. Measure idler tilt
idlers is essential for long undercarriage life.
Improper alignment can cause scalloping of 5. Check lateral position of idler.
links by the sprocket. excessive flange wear 6. Measure idler toe-in or toe-out.
on rollers and idlers. accelerated pin and
bushing wear, and dgficully in steering the Move the tractor to hri vet ground. Special
machine. alignment tool kits ar6 ni,able but if one is
not at hand most of the env lent checks can
Proper alignment basically consists of be done with a tape measure and string lines.
keeping the sprocket. rollers and idler on Always take measurements from a machined
each track frame alIcned with one another surface, one that hasn't been built up with
and parallel to the centerline of the tractor. weld.
Detected early. misalignment may be correc-
ted with minor adjustments before costly TRACK FRAME ALIGNMENT
damage has been done. Be observant: look
for uneven wear patterns. the signs of Roller Frame Toe-In Or Toe-Out
misalignment. Be careful about making hasty
judgements. though. because wear patterns Using a tape measure. measure the distance
may look like they are caused by misalign- between the rear roller shaft ends. distance B
ment but are actually caused by stressful (Figure 6-115). Now measure the distance A
working conditions such as side hills. between the front roller shafts. For this
machine. Length A should be within 1/2 inch
Following are six alignment checks that can of length B. These same measurements can
be performed on the tractor in less than 30 be taken with an alignment kit adjustable bar
minutes. (Figure 6-116).
Track Frame Alignment
1. Measure roller frame toe-in or toe-out.
2. Measure roller fr.. -ne parallelism.
3. Determine which frame is misaligned.

.15.4 MAX. TOE OUT

45'1 MAX. TOE IN

TRACTOR CENTENLINE

PERFECTLY MACHU,
FRAME 19 PARALLEL
MTN TRACTOR
FRONT OF TRACTOR ........ CENTERLINE

1,/
J
a
ROLLER FRAME CENTERLINE
REAR ROLLER FRONT ROLLIR
SHAFT SHAFT 119317
THE RECOMMENDED MAXIMUM TOE AT THE IDLER SHAFT CENTERLINE IS .2510
(.635 CM.). THE MAXIMUM COMBINED TOE FOR 80TH FRAMES IS .50n (1,27 CM.).

(6-115) Courtesy of Caterpillar Tractor Company

: 372
 6:80 TRACK MACHINE UNDERCARRIAGE

'.... ...11.
A

..

--11.-- DISTANCE OF TOE

. . ...ic ._, 4011

«fi___fi

iwEASIJMNG BETWEEN ROLLER SHAFTS WITH AN ADJUSTABLE BAR AN3 COLLAR.

AN ENLARGED VIEW Or THE COLLAR IS SHOWN IN THE INSET.
(6-116) courtesy of Caterpillar Tractor Company

Roller Frame Parallelism

To further Check parallelism of the roller
frame. measure the two diagonals from the
front roller shaft on one roller frame to the
rear roller shaft on the other frame. The two
diagonals should be within the acceptable
tolerances Elated in the service manual.
In the Figure 6-117 the frames are misaligned
because the distances A and B are not the
same.

,:r
Z
3
ROLLER FRAME CENTERLINE
.MI

1.,..1
...-.'
.
,,,
...
z
.,
., TRACTOR CENTERLINE
......
..
,..

..
..,
--.-
'RENT OF TRACTOR

0
...
ROLLER FRAME CENTERLINE.
4.0
REAR ROLLER FRowi. ROLLER
SHAFT SHAFT
(6-117)

373
t.k
 TRACK MACHINE UNDERCARRIAGE 6:81

Which Frame Is Misaligned?

In check two the frames were found to be
misaligned. Check three will show which
frame is misaligned or will show if both are
misaligned.
(a) Two measurements are made with a
tape. distance A and distance B in
Figure 6-118. In this case A and B are
the same. anJ therefore the track
frame represented by the top line is
aligned.

ROLLER
SHAFTS
REAR
=1
2nd 3rd 4th 51h 6th 7th

FRONT OF
B TRACTOR

TRACTOR CENTERLINE

REAR 2nd 3rd 4th 5th 61h 7th

(6-118) METHOD OF DETERMINING RELATIVE
POSITION OF ROLLER FRAMES
(b) Now two more measurements are
taken. distance C and distance D in If the roller frames are misaligned
Figure 6-119. Since D is longer than beyond acceptable tolerances. the
C the track frame represented by the track frame would have to be
bottom line is toedout. If D happened removed to correct the alignment.
to be shorter than C. then the frame
would be toed-in
ROLLER REAR 2nd 3rd 4th 5th 6th 7th
SHAFTS UT 111- 71E- 111-
FFiONT OF
TRACTOR

TRACTOR CENTERLINE

DIFFERENCE IN LENGTH
INDICATES FRAME IS
TOEDOUT

.
REAR 2nd 3rd
T 5 14 94 4in 5th nth 7th
(6-119)

374
6:82 TRACK MACHINE UNDERCARRIAGE

IDLER ALIGNMENT
Idler misalignment is one of the most common
undercarriage problems. Located at the front
of the machine. the idler takes the brunt of the
shocks hitting the front of the track. Figure 6-
120 shows wear patterns of aligned and
misaligned idlers. To check idler alignment.
measurement must be taken for ideal till
lateral position and toe-in and toe-out.
1

I
FRONT TRACK ROLLER
1 Heavy Contact (Cutting If ToeIn Is 1/4 or
More) On Idler Outer Flange
2 Moderate Contact On Idler Inner Flange
3 Heavy Contact (Cutting If Toe-in Is 1,4" Or
Morel On inner Side 01 Outer Side Links
4 Heary Contact On Outer Side Of Inner Side
Links
5 Heavy Crntact On Inner Flanges
(6-120) WEAR PATTERN OF TOED-IN IDLER
enuolpsy of Foal Allis Construction IVIachinery Int.
FRONT TRACK ROLLER 1
2
I Light Even Contact On Each Side Of Idler
Flange ,..\<-
2 Light Even Contact On Both Sides Of Side
.....)
Links
3 Light Even Contact On All Flanges 01 Track
Rollers
(6-120) WEAR PATTERNTRACK AND
IDLER PROPERLY ALIGNED
Courtesy of FiaiAuts Construction MaChinery hu,

1 Heavy Contact On Idler Outer Flange

2 Light To No Contact On Idler Inner Flange
3 Heavy Contact On Inner Side 01 Outer Track
Link
4 Light To No Contact On Inner Sie, Of Inner
Track Link
5 More Contact On FlangeS

(6-120) WEAR PATTERN -IDLER OFFCENTER

TOWARD OUTSIDE
FRONT TRACT ROLLER
Courre 4y of Font AnrS ConStruChere Machretery 1.rtr.
 TRACK MACHINE UNDERCARRIAGE 6:83

Idler Tilt In some cases tilt can be corrected by moving

shims from one side to the other (Figure 6-
To check idler vertical alignment or till, a 122). In other cases tilt will be caused by wear
plumbed line is dropped from the outer edge on the bearing supports or track frame rails.
of a track shoe and a measurement is taken at
To correct this more serious Problem the idler
the top and at the bottom of the idler (Figure will have to be removed and wear strips
6.121) If the two measurements are not the
and/or bearing support brackets replaced.
same. the idler is tilled

PA-32715.A

(6-121) VERTICAL ALIGNMENT CHECK AT

TOP OF FRONT IDLER
Courtesy of International Harvester

Flm=._ (6.122) IDLER ADJUSTMENTS

Courtesy of Caterpatar Tractor Co
A

Idler Lateral Position

The idler can get shifted sideways (Figure 6-
123). A visual check lining up the center
flange of the idler with the first track roller will
tell If the idler lateral position is out. Also. a
wear pattern on a side of the idler center
flange. caused by a crowding of the links, will
indicate incrrect lateral position. To correct
the lateral position shims are moved from one
side of the ider to the other (Figure 6-124).
Note that this set of shims is different than
that used to correct tilt.

.
IDLER.,
i I 11

A-32714A
il! II
.141I II -
(6-121) VERTICAL ALIGNMENT CHECK AT
BOTTOM OF FRONT IDLER IDLER
Courtesy of International Harvester
BRACKET
1
11111 11
FRAME
1 II/0 II
III
LL Y
(6-123) IDLER NOT CENTERED
Courtesy of John Deere Ltd
376
 6:84 TRACK MACHINE UNDERCARRIAGE

ALIGNMENT OF EXCAVATORS, SHOVEL

AND CRANE TRACK FRAMES
Track frames for excavators. shovels and
cranes are usually an integral part of the
truck frame or car body. and are therefore not
prone to the same misalignment problems as
crawler dozers and loaders, However, the
components must still be mounted straight
and the front idler must be kept in alignment
so the track will lay straight with a minimum of
wear on the other components.

(6-124)
Cu4riesy of Caiespoihr Tractor Co

Idler Toe-In and Toe -Out

Measure from the inside front face of one idler
to the inside front face of the other idler Now
measure from the back inside face of one
idler to the back inside face of the other idler.
A difference of measurement will indicate a
toe-in or toe-out problem (Figure 6-125). To
correct toe-in or toe-out, the idler has to be
removed aid any worn wear strips or bearing
support brackets must be replaced.
IDLER LESS
'1 CLEARANCE
WILL APPEAR
ON THIS
SIDE
TO Al:GII
IDLER
REMOVE
SHIMS PATH OF
HERE TRACK TO ALIGN
CHAIN IDLER REMOVE
SHIMS !RE

TOE00i (6-125) TOE-IN

IDLER NOT ALIGNED WITH ROLLERS AND SPROCKET
Courtesy oi John Deere Lid

377
 TRACK MACHINE UNDERCARRIAGE 6:85

QUESTIONS UNDERCARRIAGE
SCHEDULED MAINTENANCE
1. List four stress factors that can cause ac-
celerated undercarriage wear.
2. Name the two types of wear that occur
on the track pins and bushings. and
briefly explain the damaging effects tha.
occur as the wear increases.
3. What are the advantages of sealed and
lubricated tracks over sealed tracks?
4. What will a Percentage Worn Chart tell
you?
5. Refer to the Percentage Worn Chart
given in this section to answer these
questions.
(a) If a track roller on a D9 was
calipered and found to be 10.1 inch.
what would be its percentage worn?
(b) If the links on a D8 (158839-40)
measured 4.3 inches. should the
links be rebuilt?
6. Briefly explain how to measure pin and
bushing wear.
7. What does turning pins and bushings
achieve?
8 if a sever elyworn sprocket is used with a
new track chain. would it cause
problems? Briefly explain.
9. Track alignment involves keeping the
and
aligned with one another
and parallel to the centerline of the trac-
tor
10. What is an obvious sign of misalign-
ment?
11. What is the most common cause of idler
misalignment?
12. In what three ways may an idi.e; be
misaligned?
13. Briefly explain how to tell if two track
frames are parallel.

3 78
 6:86 TRACK MACHINE UNDERCARRIAGE

SERVICE REPAIR ON TRACK Positioning The Master Pin Or

MACHINE UNDERCARRIAGE Master Link For Removal

REMOVAL AND INSTALLATION OF TRACKS The position in which the master pin or link is
put prior to removal is largely a matter of
Removal of a crawler machine undercarriage. preference. Depending on what service is to
although not highly technical. is a major job in be aone on the machine. one positron may be
that you are removing large. heavy pieces of more advantageous than another. For exam-
equipment Suitable jacking and lifting equip- ple. if work is to be done on the final drive a
ment is required. and solid blocking position toward the rear would be more con-
necessary to support the machine. Since venient.
working with heavy machinery is always
PotentlE 'If dangerous. safety must be Removing The Master Pin
foremost in mind when removing or installing
troilerca cage components. Safety Precaution to prevent injury to your
feet. before removing the pin place a block in
A track machine's service manual has step- front of the track to support the track when it
by-step procedures showing how to remove or is released. Always keep hands and feet clear
install the tracks. track frames and track when separating or joining tracks.
frame components. Until familiar with a
machine. you should have the martual in front The way master pins are held in position
of you and follow the steps. When the job be- varies Irom machine to machine. but the
comes routine the manual will no longer be as method of removal is similar A hydraulic pin
important. but you will always know where to press (Figure 6-126) is the accepted tool for
find any procedure you are uncertain of. removing pins When a press is not available.
a large hammer and drift may do the job
The relationship between this book and ser- (Figure 6-127). Master pins on large machines
vice manuals should be pointed out hare This however. can be very difficult to remove with a
book is not a substitute for service manuals. it hammer and drift. Caution: when hammering
will not present detz.led. step-by-step service out a pin use eye protection because of the
and repair procedures The material in these danger of flying metal chips.
pages is intended to supplement service
manuals. to indicate what service repair is
done on a component. to summarize service
procedures. to stress a certain procedure or a
safety Precaution. and generally to provide
helpful practical Service tips and information
not usually found in the manuals.

SUMMARY OF STEPS TO REMOVE

AND INSTALL TRACKS
1 Slacken the track
2 Position this master pm or master fink for
convenient removal
3 Rem, ,e the master pin or ..isconnect the
ruister link.
4 Remove the track and rot! and tie It for (6 -126)
777228

storage or shipping Cot; inSV 01 .1 i Case

5 Install the track
6 Adjust the track

Slacken The Trick

1 Slackening and tightening the tracks is
covered earlier in the dislussion on track ten-
sion in Daily Routine Maintenance

3 79
 TRACK MACHINE UNDERCARRIAGE 6:8T

Remove The Track

1. Elevating the machine (In the shop): with
the machine raised a few inches use an
overhead crane or other suitable lilting
device to lilt the upper part of the track
and lay It out on the floor. The track can
then be pulled clear of the machine with a
fork lift or crane truck. and roiled and tied
for storage or shipping (Figure 6-1213).

(6-128)
2. Without elevating the machine: once the
track has been separated at the front of
the machine start the machine and back it
(6-127) up until it reaches the end of the track.
Courtesy of Massey Ferguson Inc Place at the end of the track. a plank that
is approximately the same width and
height as the track and about the same
length as the machine. Back the machine
onto the plank (Figure 6-129).

.ee

Oa= 0000000 ffcmcilt*

Courtesy of Tere* General motors Corprrabon
(6-129) REMOVING TRACK CHAIN
Caution: When using the plank method
to remove both tracks. be sure the
machine is on level ground. Should it be
on an incline. the machine could roll be-
THIS END OF cause there is no way of braking it once d
SHOE SHOULD is oil the tracks.
LEAD
Installing The Track
Note: There is a right and wrong way to in-
stall tracks. The grouser bar is closer to one
side of the shoe than tho other aid it is this
side of the shoe that should lead the track
towards the front of the machine. as seen in
Figure 6-130.

(6.130)
380
..-
6:88 TRACK MACHINE UNDERCARRIAGE

1. Installing tracks on large machines 2. Installing tracks on a smaller machine

Figure 6-130 shows a track being installed Figure 6-132 shows a track being installed
on a large tractor. The top of the track is on an excavator_ The mechanic guides the
supported by an overhead crane while the track over the idlers while the machine is
machine is driven forward to the point of driven forward. This practice is suitable
recoupting. A come-along can be used. for smaller and lighter tracks.
especially on big machines. to draw the
two ends of the track together and make it
easier to install the master pin. Figure 6-
131 illustrates installing tracks on a large
shovel.

r. , a

444,t1,111.; , V=.7,

(6-130) INSTALLING TRACK 44,4.-:.** 4-.7'ffs.";

-r I. "tvsx,
Courtesy of Caterpoiter Tractor Co

(6 -132)
Courtesy of Massey Ferguson Inc

,=/ 0 .4). !rg

_O. r 1 =1;

(6.131) Courtesy of Harnesitieger Coq:u:Mon P8H

 TRACK MACHINE UNDERCARRIAGE 6:89

Joining the Track

When coupling the track be sure the seal:: are
in place. the oin is inserted correctly (Figure
6-133). and hie pin is 'ocKed by whatever
means the manufacturer suggests press fit.
lock ring, pin or bolt.

MASTER PIN CORRECTLY NSTALLED

(Later Tracks Illustrated)
4
INSTALLING SEAL WASHERS AND SPACER
(Later Tracks Illustrated)
I -Spacer 2Coned disc seal washer
3 -Coned disc seal washer 4Master link
5Track link
5 Courtesy ol Cater Pillar Tractor Co
(6-133)

Figure 6-134 shows the assembly sequence of

a track that uses a master link. When the split
links are mated. a track shoe is put on top and
four bolls inserted.

(6-134)
Courtesy of Caterpillar Tractor Co

382
6:90 TRACK MACHINE UNDERCARRIAGE

REMOVING THE TRACK FRAME 2. Disconnect the track frame at the

diagonal brace and outboard bearing or at
The machine must be jacked and blocked to the pivot point if the frame is mounted for-
remove the trace frame. As with tracks. there ward.
IS more than one way to remove track frames.
The size of the machine, the availability of lif- 3. Using a crowbar or suitable lever, pry the
ting equipment. and the machine's location fro. t of the frame out so that it clears the
are all factors influencing the removal of the equalizer bar. Tilt the frame inwards so
track frame. In terms of safety on this job. it's that the diagonal brace clears the under
enough to say that a track frame of a 09 side of the machine and roll t;le track
weighs about four and a half tons. frame forward on the track.
One way to remove the track frames in a shop Removing the frame as above may sound easy
IS with an overhead crane or a chain block. but in practise it can be quite difficult.
The slings are placed :round the carrier especially on larger machines Precautions
rollers which give a fairly good balance point should be taken with hands and feet when
(Figure 5-135). Once the frame has been doing this job.
disconnected at the outboard bearing and at
the diagonal brace. the frame can be pried Removing Track Frame Components
free of the equalizer bar and lifted clear
(Figure 6-136). When overhead lifting equip- If cleaning equipment is available (steam
ment is not available, mobile machines like a cleaner or high pressure washer) clean the
crane truck or fork lift can be used. frame before removing components.
Removing most of the components from the
track frame is a relatively straightforward job.
Refer to the service manual. though. before
removing the recoil mechanism and hydraulic
. 1:-.
adjuster, because the method of removing
i
..
, ;,..,.- \ h.
..)
,.
..1 them will vary from machine to machine.
"i
1 .4___
V t ...t1 1

144" Vr47,4VV...A .: After removing the components. the track

11'11.3: v:itY.:fire1171 .11§11.

ilm'Tqt:7414141 frame should be checked thoroughly for

cracks. twists. bends and any other evidence
-tintIllt fel of damage and wear. Minor repairs will in-
(6-135) clude:
REMOVING THE TRACK ROLLER FRAME 1. Removing any broken bolts.
Courtesy of Catefpillar Tractor Co
2. Tapping out all threaded holes and
repairing any worn holes.
3. Welding any cracks and worn areas. (This
will usually be done by a journeyperson.)
4. Sanding all bolting surfaces with a disc
sander and a coarse disc to remove paint
and rust build-up. Sanding will ensure a
good metal to metal contact on assembly
4
and prevent components loosening when
back in service.
(6-136) Should major repairs be necessary to the
Courtesy of Caterolioar rr ir.tor Co frames such as repairing bends. twists or
If no liftine equipment is available. as may doing extensive welding. the frames will
happen in the field. it is possible to remove generally be shipped to a shop equipped for
this kind of work. Special jigs and presses are
the track frame in the following way:
required and are not normally found in smaller
t. Leave the track under the track frame. shops.
Jack and safely block the machine high
enough so that the sprocket clears the
track chain.

= 383
 TRACK MACHINE UNDERCARRIAGE 6:91

SHOULD TRACK FRAME COMPONENTS 3 Parts Availability demands world-wide

BE REPAIRED OR REPLACED? for heavy equipment steel parts have in
Repairing or replacing track frame com- the past created a parts shortage. If a part
is difficult to gel. it is more likely to be
ponents is a controversial subject with op- maintained and repaired.
posing views held on what is the best policy to
follow The decision whether to repair or to A discussion follows on what types of repairs
replace track frame componects depends on are done to the different undercarriage parts.
a number of factors. Some of these are"
UNDERCARRIAGE REPAIRS
1 Working Conditions Some abrasive
Weld Build Up To Restore Running Surfaces
materials that a machine may work in will
cause accelerated wear on parts and Worn running surfaces and flanges of track
make repair impractical. rollers. carrier rollers and front idlers can be
built up with weld to their original diameters.
2 Economics the cost of parts. labor and The welding is done by a machine which
downtime must be balanced against the deposits a much more uniform surface than
cost of running the undercarriage to could be done by hand. Building up worn
destruction Some companies feel produc- tread surface with weld can extend the life of
tion is more important and they will run the part 70 to 90 percent (Figure 6-137 and
the undercarriage until it stops. Other 138).
companies consider it a proven fact that a
good preventive maintena ice program
combined with repair pays off.

:,
(6-138)
,r,41114 HuLLER, IDLER AND LINK
WITH BUILT UP TREAD SURFACE
PARTS WITH TREAD SURFACES
BUILT LIP
Courtesy 01 Terex General Motors Corportion

Recoil Mechanisms
The recoil mechanism generally requires little
repair. It is usually removed from the track
frame. visually inspected and reinstalled. If
11AI. veil"-
Mir'
any damaged or broken parts are found.
though. they should be replaced. Each type of
recoil mechanism coil spring. disc and
conical spring, or gas charged cylinder haS
w..

specific disassembly and reassembly steps

and safety precautions to be followed. Always
(6-137) WELDING MACHINE refer to a service manual before attempting to
work on a recoil unit.
Courtesy of Caterpillar Tractor Co

384
1
6:92 TRACK MACHINE UNDERCARRIAGE

Coil Spring Recsil Mechanism

When assembled. the springs are compressed
to a specific length and held by a through bolt
before being installed in the track frame.
Once installed. the nut (No. 1 in Figure 6-139)
on the tension bolt is backed off and locked.
and the spring is held by stops on the frame.
Attempting to remove the recoil mechanism
without retightening the nut could cause in-
jury; when the front stop bolts are removed
the extreme force of the spring could shear
the last few threads on the through bolt and
the mechanism would fly apart. TM?!
1- Cylinder. 2-Rings. 3-Packing. 4-Rellei valve. 5-Ball
1 2 3 check assembly. 8-Washer. 7-Snap ring. 8-Piston.
......... . ' ....,'.1.
,N ,At:z (6-140)
,
4 ''''S \ , Courtesy of Caterostlar Tractor Co

Gas Charged Cylinder

s, .,'7 :11'
..... The gas charged cylinder is the recoil
mechanism and the hydraulic track adjuster
i61$31 5 8 7 all in one. Since the cylinder is under high
pressure. caution must be used when working
RECOIL SPRING ASSEMBLY
on it. To remove the cylinder from the track
1 -Nut. 2-Recoll spring. 3-Housing. 4-Front cover. 5-Recoil
spring bolt. G-Front pilot. 7-Track adjusting mechanism. frame. grease is pumped into the adjuster
(6-139) cavity to retract the piston. The cylinder is
then disconnected and lifted out. Referring to
Courtesy of Caterpillar Tractor Co the service manual. grease is bled from the
cylinder and the gas charge is exhausted. To
Conical Spring Recoil Mechanism repair the gas charged cylinder. treat it as any
Conical springs require no maintenance and hydraulic cylinder.
should present no problems in removal and in-
stallation. Disassembling the spring unit once
it is out of the track frame requires a hydraulic
press because it is held together under ten-
sion.

Hydraulic Track Adjuster

The hydraulic track adjuster is an integral part
of the coil spring and conical spring recoil
mechanism. To repair the adjuster cylinder
(Figure 6-140). treat it as any hydraulic cylin-
der: replace seals. smooth burrs or scores.
and replace any worn or damaged parts. On
reassembly make sure the parts are clean and
lubricated.

385
 TRACK MACHINE UNDERCARRIAGE 6:93

Turning Pins and Bushings

Sealed Tracks
To turn pins and bushings on sealed tracks.
the track must be removed and taken to a
shop equipped with a track press (Figure 6-
141). Each pin and bushing is pressed out.
one at a time, rotated 180 degrees and
pressed back into the links. New sealing
washers are installed during the process.

REAR ABUTMENT HYDRAULIC RAM

SADDLE

I
ELEVATING
CONTROLS
TABLE

X2670

(6.141) TRACK PRESS DESIGNED TO Courtesy of John Deere Lid

DISASSEMBLE TRACKS

Lubricated Tracks Links

Bushings on sealed and lubricated tracks can Links can have their tread surface built up
be turned if their external wear becomes ex- with weld. Whether its practical or
cessive The pins. though. are not turned be- economical to do so would have to be
cause if they were the lube hole would be decided in the individual case, Generally
pointing up and could not feed oil to the pin speaking, a set of links will Iasi one Wu. -.g of
and bushing contact surface area (see Figure the pins and bushings and then will have to be
6-64). Anyway, the pins don't need to be turn- replaced.
ed because there is very little wear on them.

386
6:94 TRACK MACHINE UNDERCARRIAGE

Track Shoes Shovel and Crane Tracks

Worn track shoes can be reconditioned by Because shovels and cranes move slowly and
welding on new grouser bars (Figure 6-142). A most of their work is done standing still. they
shoe s beam strength comes from grouser are not subjected to the same kind of abuse
height. and so welding must be done before that dozers and loaders are. However. they do
the grouser becomes so worn that the shoe have some operating stresses. The machines
bends. Worn charts will give the point at are very heavy and back and forth movements
which the shoe should be rebu'lt as the machines dig and load or lift cause
some wear on the snoes. rollers, idlers and
drive tumblers. Repairs to shovel and crane
tracks are fairly limited. Some build-up or hard
surfacing is welded to the inner side of the
shoe to extend track life. Pins are replaced
when they are broken or when they become
extremely worn. Shoes are replaced when
0111111111111ir cracked or broken.

Sprockets
(6-142)
Sprocket Removal
Courtesy of Caierpiiiag Tractor Co

When the tracks and track frame are removed

Another repair that is made to standard shoes
is to deposit a hard surface weld on lop of the
from the machine. the sprocket remains at-
grouser bar The grouser should be worn tached. The method of removing a sprocket
varies because each type may be attached to
about 1'2 inch before being surfaced because
the final drive in a different way. (See the ser-
the heat from the weld will destroy the original
heat treatment.
vice manual or removal of individual
sprockets.) The most difficult sprockets to
Track shoes must he kepi tight to prevent remove are those that are pressed onto
damage to the shoes and links. Before in- splined final drive hubs To remove these
stalling new shoes on (a new or used) track sprockets requires a portable hydraulic press
chain be sure to sand all painted or rusted capable of pulling or pushing up to 100 tons.
surfaces. Paint or rust between the two sur- Such presses can be rented if a shop doesn't
faces will usually cause the shoe to loosen in have one When using a hydraulic press. it is
service. Shoe bolts should be tightened to ser- important to have correct adapters and to
vice manual specifications with a torque push in a place that won't damage the final
wrench. An example of torque Pressures is drive.
given in Figure 6-143,

PROPER TORQUE FOR TRACK HARDWARE

BOLT
DiAMETER THREADS
(INCHES) PER INCH TORQUE POUNDFOOT

9/16 18 65 + 15 plus 1/3 extra turn

5/8 18 130 + 30 plus 1/3 extra turn
3/4 16 220 + 40 plus 1/3 extra turn
7/8 14 250 + 50 plus 1/3 extra turn
1 14 250 + 50 plus 1/3 extra turn

Courtesy or calerpow Tractor Co

387
 TRACK MACHINE UNDERCARRIAGE 6:95

Caution: Before removing the sprocket. back

off the sprocket retaining nut only far enough
to allow 1/4 inch between the sprocket face .Sprocket;
and the nut. So positioned. the nut will prevent
all the parts flying onto the floor when the
sprocket is pulled loose.
Sprocket 41rive oil seal
Figure 6-144 shows an assembled press ready guard wit b lirt4eflector
to pull a sprocket. Note that the sleeve
presses against the end of the final drive gear JIAL
hub and rot against the dead axle. Figure 6-
145 shows the sprocket removed.
"A.
,d4

(6-1-16) REMOVING PIVOT BEARING

f Courtesy of International Harvester
1369111
a111141121
(6-144)
Courtesy of Caterpillar Tractor Co Pivoibeiriziir Oil seal on seal
guard
V
SEALS

4.

1110-s t
Pitot-
(
z

Pivot bracket
911 Tr"'

(6-146)
REMOVING PIVOT BRACKET ASSEMBLY
Courtesy of International Harvester
-Spam.
(6-145)
Courtesy of Caterpillar Tractor Co

Figure 6-145 shows a spoke sprocket being

removed from a small tractor having a pivot
bearing.

388
 6:96 TRACK MACHINE UNDERCARRIAGE
I
Sprocket Installation
-4.
.11
Consulting the service manual. reverse the
removal procedures. Be sure everything is
clean. the seals are in good condition and in
Place. and the splines are free of burrs. Press
on the sprocket (Figure 6-148). applying the
specified pressure. Sixty-five tons or more
may be needed. Tighten the retaining nut and

/
install the lock.

°I '''' l'. ikati-a

401111/kiir
*"..
.,.
SA

(6-146) REMOVING SPROCKET

Courtesy of International Harvester
*St SOXi
Figure 6-147 shows a sprocket segment being
removed. The segment can be taken off (6-148)
without removing the track. When installing CourtesY of Caterpillar Tractor C).
new segments be sure the bolting surfaces Sprocket and Drive Tumbler Repair
are clean and free of dirt, paint or rust, and
carefully torque all bolts in a sequence to In the past new rims were welded to some of
avoid distortion of the drive disc. the more expensive spoke sprockets and
sprocket teeth were built up. but today very lit-
tle sprocket repair is done. The hunting tooth
design, precision cut teeth. and now sealed
and lubricated tracks have greatly extended
sprocket life.
One service that is done to sprockets is swap-
ping them. if the forward drive side sprocket
wear is more severe than the revere drive
side. the sprockets can be interchanged.
Drive tumblers for shovels and cranes can be
repaired with welding build up. Shovel tracks
are not as precisely made as dozer tra-ks and
can tolerate this type of repair.

INSTALLING COMPONENTS TO THE

TRACK FRAME
Once the frame and component& are repaired
or new parts are obtained. reinstall all parts al
the reverse order in which they were removed.
(6-'447) Follow procedures given in the servft;e
Courtesy of CalorPillar Tractor Co manual. Some points to observe are
1. Mount singe and double flange roller&
alt.inately on the frame ending at the rear
with a single flange. Be sure all rollers are
mounted so thtit the tube till plug faces
the outside.

3$9
 TRACK MACHINE UNDERCARRIAGE 6:97

2. Be sure all end caps are torqued to ALIGNING THE INDIVIDUAL

specifications. TRACK SIDES
3 Install the recoil track adjuster assem- It is Important to recheck the alignment of all
bly. If d is the type that is submersed in oil. the components in respect to the sprocket
refill it to the correct level. once the track frame has been installed and
the rear roller has been aligned with the
4. If the idler is adjustable. be sure it is in- sprocket. An easy check is to attach a piece
stalled to the required low or high working of string to the rear side of the sprocket. as
height. Most important. align the idler shown in Figure 6-150. Pull the string tight at
once installed because idler misalignment an angle and move it toward the front idler as
can cause rapid wear on all the other indicated by the arrows. When the string is
parts.
parallel with the side of the sprocket check
5. Be sure to line up carrier rollers with the the relationship of the carrier rollers and front
front idler and recheck them with the idler and make any necessary adjustments.
sprocket when the frame is installed on
the machine.
6. To complete the assembly. the track
guiding guards and track roller guards are
bolted and welded to the track frame.
7. When all components are installed and
aligned. reinstall the track frame on the
machine using the same rigging and
safety practices described for removal.
8. The track frames must be checked for
alignment once installed. Figure 6-149
shows correct alignment of the track
frame with the sprocket. Note points 11
and 12 showing the clearances required
for proper operation. The sprocket must
clear the roller. Also note the diagonal
brace clearance. points 14 and 15. To ad-
just for clearance. the track frame is shim-
med in or out. STRING
2 3 4 5 10

14

15

112134 (6-145) 16

ALIGNING TRACK ROLLER FRAME WITH SPROCKET

1Cap. 2Lock. 3Nut. 4Retainer. SShints. 6Holder. 7Support. BRear
track roller. 9Drivo sprocket. 10Track roller frame. 11Clearance. ALIGN
12Clearance. 13Diagonal brace. 14Clearance. 16Clearance. (6-150)
16Steering clutch case. . TRACK
Courtesy of Caterpillar Tractor Co Courtesy of Caterpillar Tractor Co
6:98 TRACK MACHINE UNDERCARRIAGE

QUESTIONS UNDERCARRIAGE
SERVICE REPAIR
1. List steps required to remove a track.
2. Does it matter which way a track is in-
stalled on a crawler dozer?
3. If you are separating the track at the
front of the machine, what safety
precaution should be taken?
4. Running surfaces on various un-
dercarriage components can be built up
with This is done by a

5. When lifting out a track frame. where

should the sling be placed?
6. When removing a press fit sprocket. what
precautions must be taken to avoid in-
juring yourself or damaging the final
drive assembly?
7. Can sprocket segments be changed
without removing the track? What steps
are necessary when installing new
segments to ensure that they will stay
tight?
B. When a track frame is installed on a
machine, what points must be checked
for correct clearance? Briefly explain
how to correct inadequate clearance.
9. When the track frame, sprocket and idler
have been installed. what is a quick
method to check their alignment?
10. When a track is installed. the correct
must be put on the track.

391
 TRACK MACHINE UNDERCARRIAGE 6:99

ANSWERS TRACK MACHINE 9. Track rollers are bolted to the bottom of

UNDERCARRIAGES the track frame. They support the
machine's weight distributing it along
1. Two track frames the track chain as they run on it.
The components mounted on the The term single and double flange refers
frames
to whether the roller has flanges on the
The tracks outside edges (single) or on both the in-
side and outside edges (double).
2. The difference is the way the un-
dercarriages are mounted. 10. Bushings have greater load carrying
Dozer track frames can move up and capacity. Also, they are cheaper and
down independently of one another, require less space.
pivoting from a point near the rear of the 11. On the top of the track frame. Their pur-
tractor. This set up permits maximum pose is to support the top of the track as
track contact with the ground when it travels from the sprocket to the front
working in rough terrain. idler.
Loader track frames. on the other hind.
are mounted rigidly, providing a stable 12. A dozer or loader track consists Of two ,
working platform. rows of links joined together by pins and
bushings with shoes bolted to the links.
3. The track frame is a housing to which all A shovel track consists of heavy shoes
the undercarriage components are pinned together to form the track. The
mounted. backs of the shoes are grooved for the
rollers to run in. and notched to fit the
4. Diagonal brace drive lugs on the tumbler.
Guide roller
13. The distance center to center between
5. The recoil mechanism is located behind two pins.
the front idler. Its purpose is to act as a
shock absorber and provide some give 14. Master pin
for the track should something get Master link
caught in the tracks.
15. A dozer shoe has a raised grouser bar to
6. The track adjuster is located in the track give the machine traction. A shovel shoe
frame between the recoil mechanism and is flat.
the front idler. Three types of track ad-
justers are: 16. A double or triple grouser bar shoe.

Hydraulic 17. Because the wider the shoe the greater

the stress on other undercarriage com-
Manual (threaded rod) ponents.
Combined recoil mechanism and 18. House rollers are placed between the up-
hydraulic track adjuster (gas charged) per and lower works of the shovel or
7 Use the high position, which puts less crane and permit the upper works to
strain on the undercarriage when turn- make a 360° revolution. The rollers travel
ing. unless the greater stability of the low in a circular path on the lower works.
position is required when the machine is The hook rollers travel 'n circular
equipped with heavy front-end at- grooves under the house roller path and
tachments. keep the upper works in line.
8. A sprocket drives the track. Types of Most modern excavators use a large ball
sprockets are: bearing circle (an anti-friction bearing)
which essentially does the same job as
Spoke the house and hook rollers.
Disc 19. To protect the rollers. pins and bushings
Ring from rocks and other debris. Roller
guards also help keep the track aligned.
Segmented

392
6:100 TRACK MACHINE UNDERCARRIAGE

ANSWERS UNDERCARRIAGE DAILY,

ROUTINE MAINTENANCE
1. Operator's manual for the machine.
2. To spot potential problems and repair
them before major damage is done.
Check the:
tracks
track tension
sprockets. rollers. carrier rollers.
idlers
guards and covers
3. Measure the amount of track sag be-
tween the idler and the first carrier roller.
4. Tight tracks accelerate wear on un-
dercarriage parts and reduce drawbar
horsepower. Loose tracks also ac-
celerate wear on undercarriage parts
and increase the chances of a track jurn
ping off.
5. ... tighten ... vented. ... added ..
tighten ...
6. Read the venting instructions often
located on a decal inside the track ad-
juster opening. and only turn the vent
screw the recommended amount
(usually a part of one turn).
Keep your face clear of the vent
opening.
Cover the vent screw with a rag.
Place a block in the sprocket and
back the machine up to ensure that
the pressure is completely relieved.
7. The drive chain. Shims.

393
 TRACK MACHINE UNDERCARRIAGE 6:101

ANSWERS UNDERCARRIAGE 11. Wear on wear strips and bearing sup-

SCHEDULED MAINTENANCE ports.
1. Environment 12. An idler can be tilted. toed-in or toed-out.
Type of work or pushed to either side.
Speed 13. Measure the distance across the two
Operator front roller shafts. Measure the distance
across the two rear roller shafts. If the
2. Internal and external bushing wear and distances are not the same (within a
external pin wear. As this wear increases given tolerance), the tracks are not
the track stretches. When the track chain parallel.
stretches the pitch of the chain and the
pitch of the sprocket no longer match.
The sprocket wears and the tracks
loosen, causing accelerated wear to
other undercarriage parts.
3. Pin and bushing wear is almost non-
existent. This greatly reduces wear on
the other undercarriage components.
Quieter operation.
Less friction and thus more available
horsepower.
4. The percentage the component is worn
before it should be rebuilt.
5. (a) 75 percent _

(b) No. They have gone beyond the

rebuild limit and it would not be
economical to rebuild them.
6. Tighten the track. Place a block be-
tween the sprocket and track chain
and back the machine up.
Take a measurement on the top half of
track. staying at least two links away
from the master pin section.
Measure from the front on one pin to
the front of the fifth pin away. This
measurement will include four links.
The total measurement obtained
divided by four will give the average
worn pitch length. Compare it to the
original pitch length and calculate the
difference.
7. Turning restores the track pitch.
8. Yes the sprocket pitch would not
match the chain pitch, and therefore ac-
celerated wear would occur to the out-
side of the bushings.
9. ... sprocket. rollers, and idler , .. ,
10. Uneven wear patterns on undercarriage
components under normal working con-
ditions.

394
6:102 TRACK MACHINE UNDERCARRIAGE

ANSWERS UNDERCARRIAGE
SERVICE REPAIR
1. (a) Slacken the track.
(b) Position the master pin or master
link for removal. and separate the
track.
(c) Back the machine off the track onto
a plank or raise the machine and
pull the track clear of the machine.
2. Yes. The track must be installed so that
the grouser bar leads the track towards
the front idler.
3. Place a block to support the track when
it is released.
4. .... weld. ... welding machine.
5, Around the carrier rollers.
6. Back off the sprocket retaining nut
just enough to allow about 114 inch
clearance between the sprocket face
and the mit; this will prevent the
sprocket from flying off when pulled
free.
Use correct adapters with the putter
and pull only against the hub. not
against the dead axle.
7. Yes. Clean the bolting surface of drive
disc and segments so that they are free
of dirt. paint or rust. Torque the bolts
evenly and to the recommended
pressure.
8. Clearance between:
(a) The sprocket sides and rear roller
flange,
(b) The diagonal brace and the rear
housing on the pivot shall (if the
track frame has a diagonal brace).
Shim the track frame in or out.
9. Tie a piece of string onto the outside of
the sprocket and stretch the string to the
front of the idler center flange. Check to
see that the sprocket. carrier rollers. and
idler center flange all touch the string.
10. .... tension ...

395
 TRACK MACHINE UNDERCARRIAGE 6:103

TASKS TRACK MACHINE 2. Using the correct tools. lifting equipment

UNDERCARRIAGES and procedures outlined in the service
manual:
Do these tasks on one of the following
machines: crawler loader. crawler dozer. ex- (a) Jack and securely block the machine
cavator. shovel or crane. at a height at which the track frame
can be safely removed.
DAILY, ROUTINE MAINTENANCE (b) Remove the track frame.
CHECKS (c) Remove from the track frame the
1. Check the undercarriage and its related front idler. idler rollers and track
components for loose bolts. wear. cracks. rollers. Inspect the components for
chips. oil leaks. and any other visible wear and damage. and repair or
damage. Make any minor repairs; report replace any that are not serviceable.
any major service repair needed. (d) Inspect the track frame for bends.
2. Check the track tension. Adjust it if twists. and cracks. Make any minor
repairs; report any major service
necessary (refer to adjusting procedures
repair needed.
in the track adjuster opening or in the ser-
vice manual). (e) Repair or replace the track chain
assembly.
SCHEDULED MAINTENANCE (f) Remove and replace the sprocket or
1. Consulting the service manual. do a sprocket segments.
scheduled lubrication of undercarriage (g) Install the track frame components
grease fittings. on the track frame and install the
frame on the machine. Lower the
2. Using a tape measure and following the machine, and install the tracks.
procedures stated in the service manual.
measure the track frame alignment. With (h) Following procedures outlined in the
wear gauges (if available) or with a service manual. adjust the track
measuring tape. measure the wear on the tension and lubricate if applicable
track frame components listed below: the front idler. idler rollers. and track
rollers.
Front idler
Idler rollers
Track rollers
Pins and bushings
Record the measurements and look them
up on a Percentage Worn Chart. Report
parts that have reached or are ap-
proaching the rebuild limit. Report any
needed repairs or replacements.

SERVICE REPAIR
1. Following procedures outlined in the ser-
vice manual, slacken the track And
position the master link or master pin for
convenient removal. Taking safety
precautions. remove the master link or pin
and with the correct lifting equipment lay
the track flat on the ground.

396
 BLOCK

Track Machine
Final Drives

397
 TRACK MACHINE FINAL DRIVES 6:105

PURPOSE OF TRACK
FINAL DRIVES
As was seen if, elm< 5. Power Trains. several
assemblies are needed to transmit power from
an engine to the tracks. Power from the
engine's flywheel is transmitted through a
torque converter. transmission. a bevel gear
assembly, steering clutch. final drive, and
finally to a sprocket which drives the track.
A final drive is basically a reduction gear
assembly that converts engine horsepower
into powerful torque capable of pulling very
heavy loads. The question might be asked,
why are final drives necessary? Couldn't a
transmission provide this speed reduction and
torque increase? The answer is that the trans-
mission would have to be very large to provide
the required torque. Also. the tremendous
(6-151)
torque or twisting load would have to be
Courtesy of Calerptilar Tractor Co
carried by all the other power train com-
ponents from the transmission out. It is much The final drive pinion meshes with the large
more practical to provide the final reduction final drive gear. Although ifs not clear in
at the sprocket where the torque is needed. Figure 6-151. the sprocket is pressed onto a
Final drives have the advantage of giving hub which is either part of the final drive gear
torque increase while allowing the other or is bolted onto it. Thus. as the final drive
power train component: to carry lighter loads. gear turns. the sprocket turns.
TYPES OF TRACK Some machines have a solid hub. while others
FINAL DRIVES have a hollow hub that fits over what is called
the sprocket or pivot shaft (Figure 6-152). This
There are three types of final drives used on shaft is a non-moving "dead" axle pressed
crawler dozers and loaders: into the final drive housing. The final drive
Single reduction final drives gear. hub and sprocket assembly. supported
by inner and outer bearings. all turn on the
Double reduction final drives sprocket shaft.
Planetary final drives (outboard and
inboard)

Single Reduction Final Drives PIVOT SHAFT

Power comes into the final drive through a P. AL -.
drive pinion connected to the steering clutch
output drum (Figure 6-151). The pinion ex-
tends out from the steering clutch housing
and is supported
housing.
by bearings within the
*I
I
..,, It

SPLINES

(6-152)
Courtesy o! International Harvester

398
6:106 TRACK MACHINE FINAL DRIVES

Another function of the sprocket shaft is to

support the track frame. This function gives
the shaft its other name. pivot shaft. The track
frame is attached to the rear of the machine at
the sprocket shaft. which acts as a pivot point
for the track and track frame to move up or
down.
Note that not all machines use this kind of
sprocket shaft arrangement. The track frame
on these machines are mounted ahead of the
final drive housing to a shaft that is attached
to the front of the rear main housing. When no
sprocket shaft is used, the final drive, gear
hub. and sprocket are a live axle and are sup-
ported by bearings in the housing and in the
case. The final drive case. gears, and shaft 44.):1X.
can be removed as an assembly (Figure 6- .
153). Machines that don't have sprocket shafts
are generally either smaller tractors such as
fjtAN
crawler loaders. or have outboard planetary rt ira? ..44
final drives. (6-153)
Single reduction final drives use a splash Courtesy of Massey Ferguson Inc.
system of lubrication. As the gears move, oil is The single reduction pinion to final drive gear.
picked up and splashed throughout the either with or without a sprocket shaft. is the
housing. most common type of final drive found on mid-
dle sized dozers and loaders. There are
variations, though. in the way the gears are
mounted and the bearings and seals
arranged, and in the way the sprocket shalt is
Sprocket drive seat covet
installed and the sprocket retained. Figure 6-
&arias cap 154 shows a detailed cross-section of a single
Picks shaft *sari oil efts
reduction final drive.
Plods, daft User oil ftal
Speocket
MO par
Piaios daft osier heath,'
Fisica shaft

Sprocket driwe sear

Plain shaft hoer heaths aster aid deflector
Sprocket deiwe gear
Sprocket driwe gear
ismer dirt deflector
Sprocket delft lcaw Spode! ',tidier set
cow wear plate /
Sprocket drive osier oil :col
Sprocket driwefeaw Oster beating wdaiser set
/awe/ sealing ft.' I
Ostee bestir( testis' dog
Sawa ON Oster heathy
Maria' wade/
Trask frame Oft bogs'
scat Maisie spies Piwot Ireacisi
Sprocket Iriwe paw riftt shaft
(anus Insist
Sprocket drove osier brads'
sir Pivot beariag
tap gips
Old ---1--7,70v Teach ham piwot
enlist washer
Track frame pivot
heeded seal

PA- P t2

(6.154) CROSS-SECTION OF SPROCKET DRIVE

Courtesy of International Harvester

399
 TRACK MACHINE FINAL DRIVES 8:107

Double Reduction final Drive Lubrication for double reduction final drives
can be either a splash or a pressure feed
The torque requirements for large tractors system. depending on the size of machine and
with greater horsepower are such that they the manufacturer. !n the pressurized system,
need a double reduction in the final drive, The oil is picked up through a screen at the bot-
double reduction provides a greater torque to tom of the housing by a gear pump driven by a
the sprocket tnan a single reduction can give slot at the end of the idler gear. The oil then
in the same space. Figure 6-155 shows a sim- flows through a full flow filter and is fed to all
plified view and an actual view of a double the vital areas requiring lubrication. In-
reduction final drive. formation about the specific flow pattern,
ANAL DRIVE PINION pump location. filters and check valves. can
IDLER GEAR AND PINION be found in the service manual.
STEERING Planetary Final Drive
CLUTCH
Planetary final drives are found on many trac-
tors. small and large. A planetary gear system
has the advantage of:
performing a high reduction within a
limited space. and
FINAL DRIVE GEAR
allowing the first reduction gears to
carry less load and thus to be lighter
(reduced gear width).
The planetary final drive is actually a double
reduction unit. It uses a pinion-to-bull-gear
(6-155) DOUBLE REDUCTION arrangement for the first reduction and a
Courtesy of Caterpillar Tractor Co planetary gear set for the second reduction.
The gear combination used to obtain power
flow through the planetary final drive is to
hold the ring gear. power the sun gear and the
carrier is driven at a reduction. Power is sup-
plied to the sprocket from the carrier. Figure
6-156 shows an outboard planetary. outboard
meaning located outside the sprocket. There
are also inboard planetaries.
I

iftotvz-
(6-155) Courtesy of Caterpillar Tr:Ator Co
The gear arrangement is essentially the same
as in the single reduction except that there is
an additional pair of gears, an idler gear and
pinion. Sometimes referred to as an in-
termediate gear and intermediate pinion.
these gears are joined together to form a pair
or cluster. Power is transmitted from the drive
pinion to the idler gear, and then from the
idler pinion to the final drive gear, giving two
reductions. 1. Drive Gear 7. Sun Gear
Guilt Shaft 8. Drive Shaft
A double reduction final drive Is assembled 3. Driven (Bull) Gear 9. Planetary Pinions
simllarily to a single reduction except that the 4. Gear Cover 10. Ring Gear
double reduction requires extra support for 5. Sprocket It Sprocket Hub
the idler gear and pinion. The bearings have 6. Planetary Housing
to be adjusted for the final drive gear once the (6 156) FINAL DRIVE POWER TRAIN
sprocket is installed. Courtesy of Terex. General Motors Corporation

4^P
6:108 TRACK MACHINE FINAL DRIVES

To trace the power flow start at the chive

pinion (1), Power is transferred to the bull
gear (3) Attached to the bull gear by a shaft
18). is the sun gear (7). Therefore, the sun gear
IS the powered member of the planetary. The
ring gear (10) is held stationary (by splines on
the houSing) and the pinions (9) and their
carrier are attached to the sprocket
Lubrication for the planetary final drive.., will
vary Outboard planetaries are usually splash
fed while inboard planetaries are pressure
fed. Figure 6.S57 gives a view of a pressure
lubrication circuit on an inboard planetary
Note the location of the filter (1), oil pump (4),
the check valve (5) that prevents dirt cir-
culating throughout the system when the
machine operates in reverse. and the pickup
strainer (8). Figure 6-158 gives a detailed
cross-section of an outboard planetary.

FINAL DRIVE LUBRICATION

i -00 litter 2 Junction block. 3Final drive
pinion lubrication Irne 4 -0i) pump
5--Ba II check valve 6Lubricahon line
7 Sprocket shaft 8 --Strainer
(6-157)
Courtesy of Caterpillar Tractor Co

401
 TRACK MACHINE FINAL DRIVES 6:109

29-
28

27
16 26
25

17 24
1$ 23
is 20 2122 DRIVE CASE
REF. SW.I-I

1Planetary Cover 15Sprocket

2Bolts 16Bolts & Nuts
3Lock Bolts 17Bolts & Lockwire
4Sun Gear 18Key 29Bolts
5Snap Ring 19Lock Nut 30Seal 40Bearing Assembly
6Thrust Cover 20Gear Cover 31Quill Shaft 41Bearing Assembly
7Retainers 21Puller Disc 32Bearing Assembly 42Sprocket Hub
8Thrust Washers 22Snap Ring 33Axle Shaft 43 "O" Ring
9Gasket 23Bearing Assembly 34Bearing Assembly 44Snap Ring
10Planet Pinion Pins 24Lock Bolts 35Bearing Assembly 46Dowel
11Planet Pinion Gears 25Thrust Bearing 36Gear 46Internal Gear
12Bearing Assemblies 26Cover 37Bolts & Nuts 47Ring
13Ring 27Retainer Assembly 38Seal Assembly 48Body Fit Bolts & Nuts
14Bolts 28Gear 39Spacer 49Threaded Dowel Pins

(6458) Courtesy 01 %rex General Motors Corporation

402
A
6:110 TRACK MACHINE FINAL DRIVES

EXCAVATOR, SHOVEL CRANE DIRECT GEAR DRIVE

FINAL DRIVES
A direct gear drive system is usually found on
Final drives for excavators, shovels and larger mine shovels. It consists of direct
cranes serve the same purpose as those for mechanical drive from the upper works
dozers and loaders to reduce the speed through a series of gears to the horizontal
and incease the torque to the sprocket or propel shaft which in turn supplies power to
tumblers. These systems generally ust3 one of the pinion gear on the end of the shaft. Power
the following single reduction final drive is then transferred to the large final drive gew
systems: and out to the drive tumbler (Figure 6-16C).
The final drive gears are supported tv
Chain drive bearings in a housing that is partially filled
Direct mechanical with oil. Lubrication is by splash.
Hydrostatic to mechanical gears
Hydro-mechanical drive L.1-1. HORIZONTAL
PROPEL SHAFT
Chain Drive
Chain drive is the simplest of the four PINION...,
systems. Power is transmitted from the upper GEAR
works down to the horizontal propel shaft and
out to a small sprocket on either end of the
shaft (Figure 6-159). A chain links this small
sprocket to a larger sprocket connected to
the drive tumbler (see Figure 6-56). The reduc-
tion in speed is achieved by a small sprocket
driving a large one. Transferring torque by a
chain accomplishes the same results as two
gears in mesh. FINAL DRIVE

Lubrication on a chain final drive is as follows: DRIVE TuMBLE1

the cross shafts are lubricated by (6-160)

grease fittings and
Courtesy of Harmschleger CorPOra0Ort Pali
the chain and sprockets. since they run
in the open. require frequent
lubri-ation which would be done by the
service crew or the operator.

SPROCKET

-7-
HORIZONTAL PROPEL SHAFT
(6-159)
HORIZONTAL PROPEL SHAFT ViEWED Courtesy of Bucyrus Etie CO
FROM THE BOTTOM OF THE MACHINE
LOOKING UP

403
 TRACK MACHINE FINAL DRIVES 6:111

HYDROSTATIC FINAL DRIVE HYDRO-MECHANICAL DRIVE

Contrary to its name, the hydrostatic final Some of the large mining shovels use a
drive still uses a single reduction gear assem- hydraulic motor for propel, but transmit power
bly for the final drive. The hydrostatic refers to to the final drive pinions through a trans-
the method by which power is supplied to the mission and steering clutches. From the
final drive. A hydraulic motor, not a pinions out. the same single reduction gear
mechanical gear. drives the pinion of the final train is enclosed in a housing partially filled
drive. No transmission or steering clutches with oil and is splash lubricated.
are used. Hydrostatic is a common drive
system used on small hydraulic excavators. Figure 8-182 shows a complete propel system
for a large mining shovel. Note the final drive
Figure 8-161 shows final drive housings assemblies for each track and the similarities
located at the rear of the tracks. These to the others previously discussed.
housings are partly filled with oil to provide
lubrication by splash. Also note the hydraulic
propel motors. one for each track.

HYDRAULIC
FINAL DRIVE PROPEL MOTORS
HOUSING (6.161)
Courtesy of Caterpmar Tractor Co.
PROPEL
t BRAKE
HORIZONTAL
PROPEL SHAFT CRAWLER
DRIVE SHAFT

...-...,

STEERING
JAW CLUTCH

PROPEL
BRAKE PROPEL
STEERING PROPEL MOTOR TRANSMISSION
JAW CLUTCH
CRAWLER 77*
FINAL REDUCTION DRIVE SHAFT (6-162) PROPEL MACHINERY
PINION

Courtesy of Harnischfeger Corporation POI

404
6:112 TRACK MACHINE FINAL DRIVES

QUESTIONS TRACK MACHINE

FINAL DRIVES
1. What is the purpose of a final drive?
2. What are the three common types of final
drives used on crawler machines?
3. A sprocket shalt is a axle
press fit into the housing.
Supported by inner and outer bearings
the
and all turn on the
sprocket shaft.
4. What is the advantage of a double reduc-
tion final drive over a single reduction?
4. Does a planetary final drive give a single
or a double reduction?
6. What two methods are used to lubricate
final drives? Indicate which method is
used for each type of final drive.
7. Briefly explain how a reduction is ob-
tained by a shovel or crane chain drive.
8. True or False? Double reduction final
drives are usually found on medium to
small size tractors.
9. On a hydrostatic final drive used on
many hydraulic excavators. a
drives the pinion of
the single reduction gear assembly.

405
 TRACK MACHINE FINAL DRIVES 6:113

FINAL DRIVE MAINTENANCE SCHEDULED MAINTENANCE

AND REPAIR
Scheduled maintenance on final drives is
DAILY, ROUTINE MAINTENANCE basically checking and changing the oil and
replacing the filter (if there is one) at the time
Daily. routine maintenance checks for final intervals stated in the service manual.
drives are a relatively simple task that should
be included in the Daily Walk Around In- Whenever gears work together minute par-
spection. Although most final drives are en- ticles of metal break off the contacting sur-
closed in housings and not mu..h can be seer. faces Normal gear wear produces small
of their gears and bearings. there are some traces of metal filings in the oil. When parts
final drive checks that can be made from out- start to fail. however. many more particles
side the housing: chip off and accumulate in the housing. the
oil. the filter and also on the magnetic drain
1. Check for leaks or signs of leaks at the plugs found in most gear cases. Thus. by
housing joints and at the sprocket seals. checking for metal particles in the oil. filter
and drain plug. you can keep an eye on the
2. Check for damage under the housing. condition of the gears.
Housings can be damaged especially if
the machine is working in rough terrain. Many companies use a systematic oil sampl-
Bolt-on wear plates are available to ing program to keep on top of potential
protect the underside of final drive problems. Oil samples are taken regularly
housings (Figure 6-163) from each compartment on the machine and
laboratory tested. The results from these tests
3. Check the track tension. Tight tracks are can indicate minor problems before they be-
hard on final drive bearings and can come major and also determine the ap-
cause leaks at final drive seals. proximate time that major service repair
4. If the machine is a chain drive (shovel or should be done on a component. (See the
crane). check the condition of the chain. discussion on Oil Analysis in Block 7.
its lubrication and tension. Engines.)
A scheduled maintenance check on a final
drive should include:
1. Draining the oil from the final drive
housing.
2. Replacing the filter (if equipped).
3. Checking for metal accumulation or better
still. having an oil sample analyzed (on a
regular basis).
4. Refilling the housing with the correct
amount and type of lubricant.
5. Checking to ensure there are no leaks.

Steel Final Drive Guards are bolt-on

replaceable plates which protect the
exposed portion of the final drive
case from ripped rock. large slabs or
boulders.
(6-163)
Courtesy of eaten:01a Tractor Co

406
6:114 TRACK MACHINE FINAL DRIVES

SERVICE REPAIR ON shows a single reduction final drive being

FINAL. DRIVES removed. (the sprocket has already been
pulled). Figure 6-166 shows the removal of
Signs of final drive problems are (1) an ac- an inboard planetary final drive.
cumulation of metal chips in the final drive oil,
(2) leaks at the sprocket seal and (3) noisy
final drive gears Not paying attention to these
warning signs could lead to a complete break 2
down of the final drive.
Although machines have different sprockets
and final drives. the basic steps involved in
gaining access to the final drive and in
disassembling Its gears and bearings are
fairly similar. Following is some general in-
formation on final drive removal and repair.
Detailed service procedures for specific final
I
drives are found in service manuals.

Final Drive Removal

1. Depending on the machine. to get at the
final drive:
(a) The track has to be disconnected (ifs 3
most convenient to break the track at 141331
the sprocket end).
(6-164)
(b) The track may have to be removed. REMOVING FINAL DRIVE ASSEMBLY
(d) The track and track frame both may 1Rear bracket. 2Chain. 3-8M4856 Sleeve
have to be removed.
Courtesy of Caterpillar Tractor Co
2. Raise the machine and block it securely
with large wood blocks or with the correct
size metal stand.
3. A general rule before disassembling any
component 8S to clean the outside of the
housing(s) at the gasket joints. It is a poor
practice to open up a gear case without
first cleaning it (even if the gears inside
are damaged) because dirt can get inside
the case and once there. is difficult to
clean. Note that when reassembling a
gear case all dirt must be removed from
the housing because the dirt can damage s.
the moving parts.
A steam cleaner or high pressure washer
is ideal for cleaning housing joints. When
this equipment is not available (i.e.. in the
field), use a wire brush to remove the bulk
of the dirt, and a bristle brush and solvent
to complete the job.
4. After the outside of the housing is cleaned
drain the oil. ariee411111411r

5. There are various ways of removing and OP A.

disassembling final drives. Figure 6-164 (6-165)

shows a sprocket and final drive being REMOVING PINION SHAFT OUTER BEARING
removed as an assembly. Figure 6-165 Courtesy of International Harvester

407
 TRACK MACHINE FINAL DRIVES 6:115

I/

(6-165)
148341 1 2 40
(6-166)
Courtesy a International Harvester REMOVING FINAL DRIVE CASE
1Steering clutch case 2Ferial drive case.
Courtesy of Caterpillar Tractor Co

(6-166)
REMOVING SPROCKET
8Guards. 9Metal floating ring seals T44303
Courtesy 01 Caterpiilar Tractor Co (6-166)
PLANET CARRIER REMOVAL
1-8M4856 Sleeve
Courtesy 0 Caterpillar Tractor Co

408
6:116 TRACK MACHINE FINAL DRIVES

Removing and Installing Sprocket Shaft broken a thorough inspection for potential
failure spots should be made. A magnaflux
A hydraulic press is needed to remove a dead machine or similar crack testing equipment is
axle that is bent beyond allowable tolerances the most reliable way of checking gears if
(Figure 167). To install a new shaft, a threaded such testing equipment is not available. a
adapter is screwed onto the shaft. and then visual inspection may be sufficient. By ac-
the shaft is driven with a sledge hammer tight cumulating knowledge and experience of
on its taper in the housing (Figure 168). The gear wear, it's possible to tell by sight when a
shaft is then retained by whatever means the gear is worn to the point that it has to be
particular manufacturer uses. replaced. The apprentice should seek the
help of a journeyperson in judging whether a
gear can be reused.
Two factors should be kept in mind when
deciding whether to reuse or to replace gears:
1. Final drive gears have to carry extremely
heavy loads.
2. It is very expensive to have to repair a
final drive that breaks not long alter it
goes back into service.
Types of Gear Wear

(6-167) PULLING SPROCKET SHAFT Ig

Courtes ' Caterpillar Tractor Co.

(6.169) SPALUNG
Spelling Spalling is a common wear con-
dition which starts with fine surface cracks
and eventually results in large flakes or chips
leaving the tooth face. Case-hardened teeth
are most often subject to this kind of damage
rri9455 due to the brittle nature of the metal. Spalling
may occur on one or two teeth but the chips
(6-168) INSTALLING SPROCKET SHAFT may cause other damage to the remaining
1-5F9879 Adapter. teeth.
Courtesy of Caterpillar Tractor Co

When the shaft is driven fully in, measure the

distance from the end of the shaft to the
housing and check the figure against the
specifications in the manual. Should this
measurement be less than the required N:46.
amount (i.e.. the shaft is too far in). a worn
taper is indicated. The housing will have to be
bored and a sleeve installed, a job that would
be done by a machine shop. (6-169) ABRASIVE WEAR
Abrasive Wear Surface injury caused by
EXAMINING FINAL DRIVE GEARS fine particles carried in the lubricant or em-
bedded in the tooth surfaces. The causes are
If gear teeth are broken the gear is metal particles from gear teeth. abrasives left
automatically replaced; if the teeth are not in the gear case, or sand and scale from
castings.
 TRACK MACHINE FINAL DRIVES 6:117

Interference Wear This type of wear can be

caused by misalignment of gears which 4.tig01111111111N
places heavy stress on small areas. Also.
mating of two gears with teeth not designed to
work together will cause interference wear.
More than one wear pattern may show up, as
at teeth tips and roots. Possible causes of in-
terference wear on final drive gears could be
loose final drive bearings or a bent dead axle.
If the machine is run very long with these
problems, the interference wear would lead to (6-169) INTERFERENCE WEAR
gear failure.
Breakage Broken teeth may be the result
of many defects. Make a close study of the
other teeth before judging the cause.
Breakage can be caused by high impact for-
ces or defective manufacture. To determine if
breakage is due to overload or fatigue.
examine the broken area closely. If the break
shows fresh metal all over the break, an im-
pact overload was the cause. If the break -. .

shows an area in the center of fresh metal

with the edges dark and old-looking, the (6-169) BREAKAGE
breakage was due to fatigue which started
with a fine surface crack. Final drive gears
take great stress and often get broken.

Cracking These failures tend to be caused

by improper heat treating during manufacture.
Improperly machined tooth root dimensions 1
can also result in cracking. Most cracks
caused by heat treatment are extremely fine
and do not show up until a gear has been
used for some time.

(6-169) CRACKING

410
6:118 TRACK MACHINE FINAL DRIVES

FINAL DRIVE REPAIR 5. Thoroughly check the final drive housing

for cracks. and especially check the side
1. Generally speaking. when a final drive is for thin spots. This area of the housing
repaired, its bearings and seals are receives a lot of abrasive wear. As was
replaced. Always keep the old bearings mentioned earlier wear strips can be
and seals and compare them with the new welded to the housing underside, but if
to ensure that the right ones are put back the housing is too damaged it may have to
into the machine. The exception to the be replaced. Clean the bolting face of the
rule that final drive seals are replaced is housings with a file to remove burrs and
metal face seals (however, their tension high spots.
rings are always replaced). Examine the
face seals to see if they can be reused, 6. Before ordering parts, check all tapers
and if so, clean them, tie them together as and splines because wear at those points
a pair and store them in a dry place. will allow press fit parts such as sprockets
to work loose in a short time.
2. Pressurized oil systems on final drives
have to be completely disassembled and 7. Some installation points:
cleaned. Alt.o, the filter and any worn or
damaged parts should be replaced. pre-lube all final drive bearings and
gears before installing.
3. Whenever a major final drive gear failure use care not to damage seals when in-
occurs (and in general any gear failure), stalling them.
metal chips and filings will gather in every
possible corner. Be absolutely certain that when a sprocket is press fit be sure it is
the lubrication system and the ' . 4 ing pressed with the correct tonnage.
are free of these chips and filings or %le when the track frame is removed to
rebuilt final drive will be prematurely work on a final drive be sure on
damaged and fail. reassembly that the sprocket and rear
track roller have sufficient clearance.
4. Check that the dead axle is straight. and as well, that both sides of the
Bending of the axle usually occurs front to
diagonal brace have proper clearance
back because of the loads imposed on the
(see track frame service repair).
track frame from the front. A misaligned
dead axle can cause premature failure to after filling the housing with the correct
a rebuilt final drive. To check the dead type and amount of oil, check that the
axle, place a carpenter's square horizon- drain plug is tight and that there are no
tally on the machined faces of the housing leaks at the joints.
to the rear side of the dead axle (Figure 6- refer to service manual specifications
170), Keep the other leg of the square for all adjustments.
parallel to the shaft and measure the
distance between the end of the shaft and
the square. Take a similar measurement ai
the front side of the axle. The two
measurements should be the same. If they
are not, check the service manual for the
maximum bend allowable. As an example,
a caterpillar D6 tractor allows .125" (3.2
mm) maximum bend.
..

Courtesy ot;Caterpollar Tractor Co

411
 TRACK MACHINE FINAL DRIVES 6:119

QUESTIONS TRACK MACHINE FINAL

DRIVE MAINTENANCE AND REPAIR
1. How do tight tracks affect final drives and
what would be a sign of such an effect?
2. If a large accumulation of metal chips are
found in the oil drained from a final drive,
what would be the correct action to take?
(a) Reinstall the drain plug and put in
heavier oil.
(b) Flush out the housing. install a new
filter and oil.
(c) Report to your supervisor the
problem and schedule the machine
for repair.
(d) Start disassembling it right away.
3. List two obvious signs of a final drive
problem.
4. Briefly list the steps involved in removing
a final drive.
5. When removing a final drive, what should
be done with the metal face seals?
6. What is the most reliable way of checking
the serviceability of final drive gears?
7. What is the accepted practice regarding
bearings and seals when overhauling a
final drive?
8. How would a bent dead axle. if not detec-
ted during overhaul. affect a rebuilt final
drive?

412
6:120 TRACK MACHINE FINAL DRIVES

ANSWERS TRACK MACHINE

FINAL DRIVES
1. It provides a torque increase at the
sprocket allowing the other power train
components to carry lighter loads.
2. Single reduction
Double reduction
Planetary (outboard and inboard)
3. ... dead ... finaldrive ... final drive
gear. hub. and sprocket ....
4. Within approximately the same space. a
double reduction final drive provides a
greater torque increase than a single
reduction.
5. Considering tne whole assembly. it gives
a double reduction. The first reduction oc-
curs at spur gears. (pinion to bull or final
drive gear). and the second reduction at
the planetary.
6. Splash feed single reduction and
outboard planetary
Pressure feed double reduction and in-
board planetary
7. A small sprocket drives, by way of the
chain. a large sprocket creating a reduc-
tion; just as a small gear driving a large
gear creates a reduction.
8. False. They are found on large tractors.
9. ... hydraulic motor ....

. 413
 TRACK MACHINE FINAL DRIVES 6:121

ANSWERS TRACK MACHINE FINAL

DRIVE MAINTENANCE AND REPAIR
1. Tight tracks are hard on final drive
bearings and can cause final drive seals
to leak.
2. (c) Report to your supervisor the
problem and schedule the machine for
repair.
3. An accumulation of metal chips in the
final drive oil.
Leak at the sprocket seal.
Noise from the final drive gears.
4. Disconnect the track and lay it out of
the way.
The track frame may have to be
removed.
Clean the housing around the parting
faces.
Drain the oil.
Remove the sprocket.
Remove the cover and gears.
5. Examine them for possible reuse. If they
can oe reused. clean them. tie them
together. and store them in a dry place.
6. By magnaflux or similar crack detecting
equipment.
7. Replace them with new ones.
8. A bent dead axle would cause premature
failure of the gears or bearings.

414
6:122 TRACK MACHINE FINAL DRIVES

TASKS TRACK MACHINE

FINAL DRIVE

ROUTINE MAINTENANCE CHECKS

Check the final drive for leaks at seals and
gasket joints and for any other visible
damage. Report any major service repair
needed.

SCHEDULED MAINTENANCE
Scheduled maintenance procedures from the
service manual for final drives include the
following:
1. Drain the final drive housing. inspect the
oil for metal chips and signs of moisture.
Report any chips or moisture detected,
making recommendations for needed
repairs.
2. Replace the drain plug and refill the
housing with the correct type and amount
of lubricant.

SERVICE REPAIR
This task must be done when the track
machine is raised and has the track. track
frame and sprocket removed.
Using the correct tools, equipment and
procedures outlined in the service manual:
1. Take a suitable size container and drain
the oil from the final drive housing.
2. Clean the housing and remove the final
drive housing and gears.
3. Disassemble. clean. inspect the gears.
bearings and seals for wear and damage.
Write a service report or parts list and
repair or replace any parts that are not
serviceable.
4. Disassemble, clean, inspect and replace
non-serviceable parts in the final drive
lubrication system.
5. Practising cleanliness. prelubricate and
install the final drive gears and housing.
6. Install the sprocket, and adjust the
bearings.
7. Fill the final drive unit with the correct
type and amount of oil and ensure there
are no leaks.

415
Track Machine Steering

416
 TRACK MACHINE STEERING 6:123

HOW TRACKS ARE TURNED Operating controls (pedals or hand levers) for
steering clutches and brakeb vary with the
To turn a crawler. machine power has to be machine Some machines use separate clutch
cut to one track and then the driven track will and brake controls. whereas others combine
turn the machine in the direction of the track them Steering and braking controls are
that has lost power. Most crawlers interrupt discussed in greater detail later in this sec-
the flow of power to a track by means of tion.
steering clutches. There are three basic types
of steering systems: multi-disc clutch.
MULTIPLE DISC STEERING CLUTCHES
planetary gear. and jaw clutch.
Before looking at multiple disc steering, the
Another method of Interrupting power flow to
most common track steering system. it will be
a track is by the use of hydrostatic steering. helpful to give a brief review of the material
Hydraulically propelled machines. such as on clutches covered in Block 5. Power Trains.
hydraulic excavators. have a hydraulic drive
train component that controls power to the Clutches transmit power by friction. Engine
tracks. As well as transmitting power for clutches have three basic parts: a drive mem-
straight ahead travel. this component can cut ber. a driven member and a release
power to either track and thus provides a mechanism. Power is transmitted only when
means of steering the machine. Hydrostatic the driven member is held firmly against the
steering is a trend in modern crawlers; (or drive member. Clutch holding power or
example. John Deere is now using it on one of capacity can be increased by adding more
its crawler dozers. driving and driven plates. The capacity of an
engine clutch is increased for heavy duty ser-
Crawler steering is related to the type of vice by adding both an intermediate pressure
crawler and in some cases to the manufac- plate. driven by lugs in the flywheel, and a
turer. For example. International Harvester is friction disc splined onto the transmission
the main user of planetary clutches. Crawler shaft. For powershift transmissions still more
dozers or loaders use multi-disc or planetary plates are added to form what is called a
steering clutches. shovels and cranes use jaw clutch pack.
clutches; hydraulic excavators use
hydrostatic steering. A multiple disc steering clutch is a clutch
pack. In consists of e:
STEERING CLUTCHES AND BRAKES
1. Sp lined inner drum (the drive member) at-
Steering clutches are usually located in com- tached to a bevel gear shaft.
partments at the (ear of the machine. between
the bevel gears and the final drive assemblies. 2. Sp lined outer drum (the driven member)
There is one steering clutch for each track. In- connected to the final drive pinion shaft.
corporated with each steering clutch is a
brake. Besides providing braking for a
machine. this brake is also used as an aid in
making a turn. Cutting the power to one track
leaves one track driving and the other in
neutral (i.e.. free to move with the momentum
of the other track). The result is that the
machine makes a slow turn towards the track
in neutral. On the other hand. when a com-
bination clutch-brake turn is made (clutch
disengaged. brake applied same side). the
track without power will not be able to roll
freely but instead will slow down or com-
pletely stop depending on how much brake is
applied. Slaking the track causes the
machine to make anything from a gradual turn
to an abrupt sharp turn. This combination 1

clutch-brake turn is called a pivot turn.

417
6:124 TRACK MACHINE STEERING

3. Set of internally splined discs alternating

with a set of externally splined discs
(Figure 6-171). The internally splined discs
fit onto splines on the inner drum, the
drive member. The externally splined
discs fit into splines inside the outer drum.
the driven member. The discs are held in
contact by springs and pressure plates.
Note that the internally splined discs are
usually smooth steel, while the externally
splined discs are faced with an asbestos
material in dry clutches or a sintered
bronze material in wet clutches.

we
STEERING CLUTCH OPERATION
1Piston. 2Pressure plate. 3 Retainer.
4Uiscs. 5Steering clutch
04, -`11L.&&10`' driving drum. 6Bevel gear shaft.
(6-172)
Courtesy of Caterpillar Tractor Co.

Working in conjunction with multi-disc

steering clutches is a band-type brake wrap-
ped around the outside of the output drum
(Figure 6-173). There is one brake for each
track. The two brakes can be applied
separately along with a clutch release to give
a sharp turn, or applied together to slow or
stop the machine on a steep grade. A
variation of the band brake is a multi-disc
(6-171) brake, used by Terex; this disc brake is moun-
Courtesy of Massey Ferguson Inc ted on the outer perimeter of each steering
clutch as seen in Figure 6-174.
Figure 6-172 shows a typical multi-disc clutch.
The output drum. which also acts as the
clutch brake drum. has been removed to show CONTRACTING
the internal parts. This assembly is spring- BAND
applied and hydraulically released. Note the
number of coil springs in the center and the
hydraulic piston for release.
The same basic design of multiple disc clut-
ches has been used since the earliest
crawlers were made. There have been im-
provements in the design. though. such as the
addition of a hydraulic release and the
change to wet operation. Having the clutches
run wet in oil helps them to engage and
disengage more smoothly. run cooler and
wear longer. Wet clutches can withstand con-
siderable abuse and last much longer than dry
clutches.
(6-173)
Courtesy of Caterpillar Tractor Cu

41&
. .
 TRACK MACHINE STEERING 6:125

BRAKE APPLY
PISTON
CLUTCH APPLY
PISTON
STEERING CLUTCH
PACK
BRAKE CLUTCH Operation Of A Single Speed Planetary
PACK Steering Clutch

BRAKE RELEASE You may recall from Block 5, Power Trains,

PISTON.------ that a planetary gear set consists of three
parts: a sun gear, a planet carrier and a ring
gear. To obtain a power flow through a
BRAKE SPRING planetary, one gear must be held. one must be
(6-174) powered, and the third will be driven.
Courtesy of Terex. General Motors Corporation
In a planetary steering system engine power
Other differences in the Terex machine is transmitted to the bevel gear via the trans-
steering clutch ?nd brake are: mission and pinion. The bevel gear carrier
1 During normal operation with both tracks drives the planetary carrier and its gear
driving, the Terex clutch packs are clusters. The planet carrier (gear clusters).
hydraulically applied (not spring-applied) therefore. is the powered gear. The steering
and hydraulically released. brake disc is attached to the sun gear hub:
thus the sun gear is the held gear of the
2. When the machine is not running. the planetary. In the normal planetary gear set.
Tetex multi-disc brake is spring-applied. that would leave the ring gear as the driven
Once the machine is started, hydraulic gear. However, the steering clutch planetary
pressure (approximately 110 p.s.i.) causes is different in that there is no ring gear as
the spring to release the brakes. During such: the sprocket drive pinion shaft gear
normal operation the multi-disc brake is replaces the ring gear, and instead of running
hydraulically applied. Hence. the dif- on the outside of the planet gears. the pinion
ference with a band brake is that it shaft gear runs on the inside of them. The ac-
releases when the machine is not running tion of these three gears is very difficult to
unless it is manually applied. describe in words. but see if you can follow
the gear sequence described in the simplified
For more specific details of multiple disc planetary diagram below (Figure 6-175).
steering clutches refer to service manuals.
The following sequence occurs when a
PLANETARY STEERING CLUTCH planetary steering clutch is disengaged:
International Harvester has planetary steering 1. When the steering brake is applied the
systems on their mid and large size dozers sun gear is held.
and loaders. Single or two speed planetaries
are used depending on the size of the 2. The bevel gear powers the planetary
machine A multiple disc brake is employed in carrier and as it rotates causes the large
conjunction with single speed units whereas a gears in its gear cluster to walk around
single disc brake is used on the two speed. the stationary sun gear.
(The exception is the 1020E which has a drive
3. At the same time that the large cluster
clutch pack and a brake clutch pack. gears walk around the sun, the small
The steering planetary unit functions as an in- cluster gears, being mounted on the same
termediate drive; ifs located crossways in the shaft, walk around and drive the sprocket
tractor between the transmission and the final drive pinion shaft gear causing it to rotate.
drive. The planetary provides a gear reduction 4. The sprocket drive pinion shaft gear
and permits a power disconnection on each drives the sprocket drive pinion shaft
side for turning the tractor. Power to the which. in turn. drives the final drive pinion
tracks is transmitted from the bevel gear and so on Power is transmitted through
carrier to the planetary gear carrier and then the planetary to the find drive and finally
on through the planetary to the sprocket drive to the sprocket. which propels the
pinion shafts. machine.

419
.
6:126 TRACK MACHINE STEERING

(1) Steering brake applied,

DRIVE PINION PLANET GEAR CLUSTER Sun gear held.
ow

STEERING BRAKE
PADS

SPROCKET DRIVE PINION

SHAFT

..«
I

SUN GEAR
mo
1
PIVOT BRAKE
,I1WL-0.(MULTI-DISC)
SPROCKET DRIVE PINION
SHAFT GEAR
(Note: runs on inside of
planet gear cluster)
BEVEL GEAR & CARRIER 1..."STEERING BRAKE DISC
PLANET CARRIER
(3) Small cluster gears (2) Large gears in gear
drive sprocket drive cluster walk around
pinion shaft gear, (6-175) stationary sun gear.

in normal operation. when the machine is Planetary Operation

moving straight ahead. both steering brake
discs are applied so that both sun gears (one Planetary In Idling Motion
on each side) are held and power is trans- (Refer To Figure 6.175)
mitted with a slight reduction through the
planetaries to drive the machine. If the right 1. The sun gear is released and free to move.
steering brake (note that steering brakes are 2. The carrier (always moving) will drive the
sometimes referred to as clutches or clutch sun gear. Since the sun gear is not con-
controls) is released. the right side will idle nected to any shaft (the sun gear is
and. the machine will make a slow turn to the hollow, the sprocket drive shaft goes
right because the left track continues to drive. through it), it rotates freely.
Similarity. if the left steering brake is released
the machine will turn slowly to the left. 3. The sprocket drive pinion shaft gear is
driven by the momentum of the track and
On a Slow turn the track without power still sprocket. The swill cluster gears meshed
turns with the momentum of the machine just with the pinion shaft gear turn with it,
as the wheels on a moving car will continue to
turn when the transmission is shifted to Planetary With The Multi-Disc Pivot Brake
neutral, When the operator requires a sharper Applied (Refer To Figure 6.175)
turn, he applies the multi-disc pivot brake 1. The pivot brake slows or stops the
which will slow or stop the sprocket drive sprocket drive pinion shaft gear,
pinion shaft (and thus slow or stop the track),
allowing for a much sharper turn. The descrip- 2. The small cluster gears of the constantly
tions below tells what happens in the moving carrier walk around the pinion
planetary (t) when its idling and (2) when the gear,
multi-disc brake is applied. 3. The large cluster gears drive the freely
spinning sun gear.

:& 420
 TRACK MACHINE STEERING 6:127

Two Speed Planetary Steering Clutch SHOVEL AND CRANE STEERING

The planetary steering clutch described Shovels and cranes. like dozers and loaders.
above is a single speed model. On their larger require the interruption of power flow to the
dozers International Harvester uses two speed tracks in order to turn. However. the turning
planetaries (Figure 6-176) which have the ad- method in shovels and cranes is different than
vantage that during a gradual turn. power is that of dozers and loaders because their work
transmitted to both tracks. The two speed is requires a unique type of turn. Normally. a
essentially the same as the single speed ex- shovel or crane operates in one spot for a
cept that it has an extra brake giving it a high period of time then travels only a short
and a low range steering brake. The ad- distance before it stops and begins work
ditional steering brake has its own sun gear. again. Since the movement is slow and the
and the planet carrier has three (opposed to turns are few. a much simpler clutch than a
two) cluster gears to accommodate the extra dozer's can be used. Therefore. shovels and
Sun gear On most two speed planetaries both cranes employ jaw clutches for steering.
the low and high range brakes are single
discs while the recent TD2OE two speed has a Jaw clutches, as discussed in Block 5 Power
multi-disc steering brake. Note that only one Trains, are the simplest of all clutches con-
of the range discs on each side can be held at sisting of two toothed jaws facing one
any one time. another, one mounted on a drive shaft the
other on a driven shaft (Figure 6-177). One jaw
is fixed while the other moves on splines. for-
ward to engage the two jaws, backward to
disengagethem. Jaw clutches can be
engaged or disengaged only when the
HIGH RANGE BRAKE DISC machine is stopped and the propel clutch is
disengaged.
JAWS
SHIFTING
LOW RANGE BRAKE DISC
COLLAR
B
BEVEL. GEAR CARRIER

BEVEL GEAR
0111761 1°1! (6-177)
SHAFT

.DRIVEN
SHAFT

PIVOT BRAKE DISC

D B

A Sun Gear
B Large Planet Cluster
C Small Planet Cluster
0 Sprocket Drive Pinion Shalt Gear
(6-176) PLANETARY SYSTEM. SHOWING THE LINE OF POWER IN THE
1
HIGH RANGE POSITION Cotinesy of International Harvester

421
6:128 TRACK MACHINE STEERING

As shown in Figure 6-178. shovels use two jaw The brakes used with jaw clutches are ex-
clutches. one on either side of the bevel gear ternal contracting bands located toward the
on the horizontal propel shaft. outside of the clutches. When applied. the
bands grip a drum attached to the propel
The shift yokes operate the movable jaws On shaft. These brakes shown here are spring-
this model shifting is accomplished by air applied and air-released. Jaw clutch and
cylinders connected to the linkages The air brake controls will be discussed in detail later
cylinder controls are in the operator's com- in this block.
partment. SHIFT
YOKES HYDROSTATIC STEERING
If ....*S.}. Ar_241;-
was
The basic principles of hydrostatic steering
are dealt with here; it is covered in more
detail in later training.
Hydrostatic drive is an automatic fluid drive
using fluid under pressure to transmit engine
power to the drive wheels or tracks. In this
sytem mechanical power from the engine is
converted to hydraulic power by a pump and a
motor. The hydraulic power is then converted
back to mechanical power to drive the
machine (Figure 6-179).

The hydrostatic drive can function as both a

clutch and transmission. The final gear train
can then be simplified because the
hydrostatic unit will provide infinite speed and
JAW torque ranges as well as reverse speeds.
CLUTCHES
AL

(6-178)
Courtesy of Bucyrus Ene Co
CONNECTING
OIL LINES

PUMP

DRIVE
MOTOR WHEEL

CONTROL

X 2211 ENGINE
(6-179) HYDROSTATIC DRIVE IN A COMPLETE Courtesy ol John Deere Ltd
POWER TRAIN
9
422
 TRACK MACHINE STEERING 6:129

Figure 6480 shows the principle of PISTON CYLINDER

hydrostatic drive. Two cylinders. each con-
taining a piston. are connected by a line. The
line and parts of the cylinders contain oil.
When a force is applied to the piston on the
left. it moves against the oil. Fluids, as was 44 ....
FORCE
discussed in Block 3 Hydraulics. don't com- IN
EQUAL
press and thus the oil travels through the line FORCE
HERE OUT
and applies a force to the piston on the right CONNECTING HERE
&de. LINE
In an actual hydrostatic drive, two groups of (6-180)
pistons are used to transmit power: the group Courtesy of John Deere Lid.
sending the force is the pump and the group
receiving it is the motor (Figure 6-181). Similar
to the motor, the pump has a number of
pistons arranged in a circular block (Figure 6-
181).

CYLINDER FIXED
PISTONS OUTPUT
BLOCK SWASH PLATE
INPUT WHEEL
DRIVE
SHAFT

VARIABLE
SWASH PLATE
SWASH PLATE
ANGLE CONTROL
PUMP MOTOR
(VARIABLE DISPLACEMENT) (FIXED DISPLACEMENT)

(6-181) Courtesy of John Deere Ltd

Hydrostatic Pump
The pump cylinder block is splined to the in- As the pistons are driven into the bores by
put drive shaft and rotates with it. The shaft is their contact with the angled swash plate.
driven by the machine's engine and so rotates they apply a force which sends pressurized oil
at a speed set by the operator. Pistons in the to the motor. Thus the rotary motion of the in-
cylinder block have little rollers on the heads put drive shaft is changed first to the
which run on a sloping plate called a swash reciprocal motion of the pistons and then to
plate. The swash plate is held stationary. As the hydraulic pressure of the oil.
the cylinder block rotates, the pistons move in
and out, driven in by the closest section of the The slope or angle of the swash plate can be
tilted swash plate and out by oil pressure varied so that the vol'irne and pressure of the
coming back from the motor. The piston pumped oil varies: the greater the angle the
rollers are always touching the swash plate. greater the volume and pressure of oil. The
The workings of the circular block of pistons angle can also be reversed so that the direc-
and the swash plate. like a planetary gear set. tion of oil flow is reversed. A pump or motor
is difficult to grasp in words. However, once with a movable swash plate is called a
you see a dismantled pump or motor the variable displacement unit. A pump or motor
operation will become obvious with a fixed swash plate is called a fixed
displacement unit.

.0
423
6:130 TRACK MACHINE STEERING

5. AS THE PISTON PASSES THE

4. THE PISTONS. SHOE PLATE.
INLET. IT BEGINS TO RETURN
AND CYLINDER BLOCK ROTATE
INTO ITS BORE BECAUSE OF
THE SWASH PLATE ANGLE. TOGETHER. THE DRIVE SHAFT
EXHAUST FLUID IS PUSHED IS SFLINED TO THE CYLINDER
BLOCK.
INTO THE OUTLET PORT.

3. THE PISTON THRUST

IS TRANSMITTED TO THE
ANGLED SWASH PLATE
CAUSING ROTATION.
PISTON SUB
OUTLET PORT ASSEMBLY
SWASH
PLATE

DRIVE SHAFT
INLET PORT

SHOE RETAINER PLATE

1. OIL UNDER
PRESSURE AT INLET
2. EXERTS A FORCE
ON PISTONS. FORCING
THEM OUT OF THE
CYLINDER BLOCK

(6-182) HYDROSTATIC MOTOR

Courtesy of Sperry Vickers. Sperry Rand Corporation

Hydrostatic Motor
A hydrostatic motor is shown in Figure 6-182. As stated earlier. swash plates in motors can
Oil from the pump is forced into the cylinder be fixed or variable. A variable swash plate
bores through the inlet port. The force on the means that the displacement of the motor is
pistons at this point pushes them against the variable and thus its speed-to-torque ratio can
swash plate. They can move only by sliding be changed. When the plate is at maximum
along the tilted swash plate to a point further angle. the displacement is maximum because
away from the cylinder barrel. In so doing. the pistons travel maximum length. The motor
they cause the cylinder barrel to rotate. The runs slow but with lots of torque. As the angle
cylinder barrel is splined to the drive shaft is reduced piston travel shortens and the
(the shaft passes through a hole in the swash displacement is decreased. The motor speeds
plate). and so the shaft must turn too. up but it has less torque. Thus. by changing
the angle of the swash plate on the motor. a
The transfer of motion that occurs at the hydrostatic drive can give a broad range of
-motor is exactly opposite to what happens at speed-to-torque ratios.
the pomp: incoming hydraulic pressure is
converted to reciprocal motion in the pistons
and then to rotary motion at the output drive
shaft.

424
 TRACK MACHINE STEERING 6:131

Hydrostatic Drive System

The pump-motor is the heart of a hydrostatic
drive. However, other components are needed
to complete the drive's hydraulic system. A
reservoir is needed to supply oil, a filter to
remove dirt, and a cooler to remove excess
heat from the oil. A circuit for a hydrostatic
drive is illustrated in Figure 6-183.

FILTER

RESERVOIR COOLER

CHARGE
PUMP

I
PUMP MOTOR mom HIGH-PRESSURE OIL
LOW-PRESSURE OIL
=PRESSURE-FREE OIL
X$896

(6-183) COMPLETE SYSTEM FOR A HYDROSTATIC DRIVE

(CLOSED HYDRAULIC LOOP)
Courtesy of John Deere Ltd.
Although there is some circulation of oil Types of Hydrostatic Drives
through the cooler. reservoir and filter.
basically the pump and motor are joined in a Pumps and motors are classed according to:
closed hydraulic loop. The return line from the displacement size and
motor goes directly back to the pump. not to
the reservoir. Supply oil from the reservoir is displacement type
u ed mainly by a charge pump to maintain oil Displacement is defined as the amount of fluid
pressure. which a pump can move, or vice versa a motor
can use. during each revolution.
Displacement is directly related to the horse-
power output of the drive. As you have already
seen, pumps and motors can have a fixed or a
variable displacement. Four pump-motor com-
binations are possible:
1. Fixed displacement pump driving a fixed
displacement motor.
2. Variable displacement pump driving a
fixed displacement motor.
3. Fixed displacement pump driving a
variable displacement motor.
4. Variable displacement pump driving a
variable displacement motor.
The fourth one is the most common
arrangement used by hydrostatic drives.

42
6:132 TRACK MACHINE STEERING
VII

.0_2t,P1-

(6-184)

Hydrostatic Drives On Crawler Machines

in recent times hydraulic excavators have be-
come very common. Hydraulic propel. that is Courtesy of Caterpillar Tractor Co.
hydrostatic drive. has replaced the
mechanical propel of former excavators. Each
track side of a hydrostatically driven machine
has its own independently controlled
hydraulic motor. This motor provides both
brake and steering for the tractor. Figure 6-
184 shows the lower works of a typical ex-
cavator with hydrostatic drive. The hydraulic
motors are mounted to the final drive cases on
the inside rear of the track frames.

Hydrostatic drive allows for continuous and

independent control of the power flow to the
tracks. The tracks can be driven in-
dependently at any speed in the machine's
speed range. To steer a machine with
hydrostatic drive. power flow is reduced to
one track; the more it's reduced the faster is
the turn. For turning in tight situations power
can actually be reversed in one track so that
the tracks counter rotate enabling the
machine to spot turn within its own length.
Note that because hydrostatic steering has
continuous control of power flow to a track.
brakes are not needed as a turning aid but
they are required in multi-disc and planetary (6.185)
gear steering where power can only be cut Hydrostatic drive controls the speed and
completely and the brake is needed to stop power for each track from 0 to 6 5 mph
the neutral track from moving with the in forward and reverse. Thus. an infinite
momentum of the machine. Figure 6-185 speed range of turns is Possible
illustrates the steering advantages of a
hydrostatic system. Courtesy or John Deere Ltd

. 426
 TRACK MACHINE STEERING 6:133

Controls for the hydraulic motors are located

in the machine's cab. In Figure 6-186. the cen-
ter lever is a steering control which is used in
,IFHLirIllhlk I
conjunction with two floor pedals. one for for-
ward. and one for reverse. Most excavators
use a system of steering controls similar to
this.

(6-185) STEERING
CONTROL
Hydrostatic drive keePS the machine moving LEVER
straight ahead even when ifs corner loading
the blade during a heavy cut. Resistance on
the loaded side can be counteracted to give
uniform traCtion to both tracks.
Courtesy of John Deere Ltd

(6-186)
(6 -185) Courtesy of Caterpillar Tractor Co
With hydrostatic drive the tracks Can Counter
rotate allowing the machine to spot turn in
tight quarters.
Courtesy or John Deere Ltd

427
6:134 TRACK MACHINE STEERING

Hydrostatic drives are not only found on ex- linkages that connect the clutch control lever
cavators. Many agricultural wheeled vehicles in the cab with the clutch and connect the
use a hydrostatic drive. And. as was men- brake pedal with the brake bands Manual
tioned earlier. John Deere manufactures a controls are being phased out today and are
crawler dozer and a crawler loader that have used only on some small loaders and dozers
hydrostatic drive. They will also be found on older machines.
Controls For Multi-Disc, Planetary, and Machines with manual controls have two
Hydrostatic Steering steering clutch levers. one left and one right.
both held forward in the engaged position by
The following types of controls are used on springs. The clutches are disengaged by
crawler steering: pulling the levers fully back. Manually con-
trolled machines also have two brake pedals
manual which operate independently and are applied
boosters (manual and hydraulic) by depressing against spring tension These
full hydraulic brakes may be applied and held for parking by
a lock lever.
electric pneumatic
electric hydraulic Figure 6-187 illustrates simple manual con-
trols for one clutch and one brake. Remember
All early crawler machines had manual con- the machine will be equipped with two clutch
trols. Over the years demands for ease of con- levers and two brake pedals. Note the lock
trol. especially on larger machines. and for lever on the brake pedal. Threaded adjusters
less maintenance. have resulted in the are located within the linkage to compensate
development of the other four types of for normal running wear. Adjustment will be
steering controls. covered in the Service Repair Section.

Manual Controls (Multi-Disc Steering)

Multi-disc. although one of the oldest crawler
machine steering systems. is still Probably the
most common. Manual. hydraulic-boost and
full-hydraulic controls are used with multi-disc
steering but full-hydraulic is the most com-
mon. Manual controls are simply a series of

(6-187)
TYPICAL MANUAL CONTROL LINKAGE FOR BRAKE
Counesy of International Harvester

(6-187) TYPICAL MANUAL CONTROL LINKAGE FOR STEERING CLUTCH

Courtesy of International Harvester

428
 TRACK MACHINE STEERING 6:135

Clutch Boosters are located on the bevel gear case above the
steering clutch compartments. A separate
Mechanical and hydraulic boosters can be ad- hydraulic booster is used for each brake.
ded to manual controls to reduce the effort
required to disengage the clutch or apply the Oil is delivered to the boosters through a flow
steering brakes. Boosters are generally found divider. Regardless of their pressure
on large machines. but like manual controls requirements. the flow divider piston equally
they are being replaced by full hydraulic ac- divides the flow of oil to both of the brake
tuating mechanisms. hydraulic boosters. Thus, even though one
Mechanical clutch boosters are an over cen- brake is being applied for a turn. there is stilt
ter. spring-loaded assembly attached to the full pressure available at the other brake so
lower end of each steering operating lever that the machine can be safely stopped.
(Figure 6-188). The booster consists of a Oil from the flow divider is delivered by lines
spring-loaded plunger within a cylinder: to the hydraulic boosters and enters the
movement of the control lever causes the booster housings at the inlet port (3) in Figure
plunger to expand under spring pressure to 6-189.
assist in disengaging the clutch.
STEERING OPERATING LEVER

\ YOKE ASSEMBLY

\) BOOSTER ASSEMBLY
BOOSTER BOOT (6-189)
NOSE CLAMP HYDRAULIC BOOSTER OPERATION
CONTROL ROD PIVOT EYE BOLT
YOKE PIN
1Stop 2Valve. 3Inlet port. 4Booster piston.
5Passage. 6Lever. 7 Belicrank.
Courtesy of Caterpillar Tractor Co

When the brake pedal is not depressed. oil

RETAINING PIN flows through the passage (5) in the booster
, 8-19/32'' piston (4) and is dumped into the steering
FREANesETZBLY
clutch compartment. When the brake pedal is
OPERATING LEVER BRACKET BEFORE
depressed. the lever (6) is rotated. moving the
(6-188) valve (2) forward and restricting the flow of oil
Courtesy of Fiat Allis Construction through the booster piston (4). Oil pressure
Machinery Inc rises and moves the booster piston (4) to the
hydraulic clutch boosters do the same lob as right. The booster piston moves the bellcrank
mechanical boosters. but instead of using (7) and applies the brakes. A bumper (1) is
spring or mechanical power they use provided for each brake to prevent damage to
hydraulic pressure. Movement of the control the hydraulic booster when the brake pedals
lever activates a control valve which in turn are suddenly released.
applies hydraulic pressure to the booster
cylinder to aid in clutch release. In both cases
a small effort on the control lever has resulted
in an increased effort at the clutch yoke.
Brake boosters assist the operator in applying
the brakes both to turn and to stop the
machine. Hydraulic brake boosters are used
on most current tractors that have contracting
band brakes and full hydraulic controlled clut-
ches. Housings for hydraulic brake boosters

429
6:136 TRACK MACHINE STEERING

Full Hydraulic Controls disengagement due to clutch plate slip-

page. Even though the clutch plates may
There are many different types of hydraulic be wet or oil cooled. such slippage or par-
controls used to operate clutches and brakes. tial disengagement is not a good
Some of the common types are discussed operating practice on a regular basis.
below.
Brakes are separately controlled by two
1 Caterpillar uses a multi-disc clutch that is pedals. When a pedal is depressed. brake
spring-applied and hydraulically (lull application is hydraulically assisted by a
hydraulic. not hydraulic boosted) booster. One pedal is depressed to aid in
released. in conjunction with band brakes turning the tractor: both pedals are
that are hydraulically boosted. When a pushed to stop it.
steering clutch lever is pulled to the
released position, oil under pressure is Figure 6-190 shows a Caterpillar steering
directed through the control valve to the system with full hydraulic clutch release
clutch release piston (see Figure 6-172) to and hydraulic booster brakes. Note the
disengage the clutch. Releasing the con- two section pump; in this case the large
trol lever will dump the oil from the clutch section supplies the steering clutches and
piston, allowing the springs to engage the the small section the brake booster.
clutch again. Partial movement of the
clutch lever will, in turn, give partial

OIL FROM LARGER 1

SECTION OF PUMP I
im OIL FROM SMALLER
' SECTION OF PUMP
0 SUPPLY OIL
0 RETURN OIL
I/INACTIVE OIL

(6-190)
FLOW OF OIL
1 Brake booster 2Booster piston, 3Pressure rebel valve 4Flow divider 5Line.
6-- Steering clutch hydraulic control 7Orifice. 8Filter 9Filter by-pass valve. 10Pump
11Oil cooler 12Steering clutch pressure relief valve 13Suction line
14Screen 15Piston. 16Line
Courtesy of Caterpillar Tractor Co

4 .3 0
 TRACK MACHINE STEERING 6:137

2 Terex, also uses hydraulically controlled 3. international Harvester uses several types
multi-disc clutches. but instead of band of steering controls. The controls
brakes they use multi-disc brakes (See described here are their newest design
Figure 6-174). The disc brakes are spring- used on a TD2OE single speed steering
applied when the machine is stopped. On drive.
start-up. hydraulic pressure applies the
clutches and releases the brakes. The single speed steering drive contains
Movement of one of the steering clutch one drive clutch pack and one brake
control levers dumps oil from the steering clutch pack for each side of the machine
clutch to release it. Further movement of (Figure 6-191). The drive clutch packs are
the same lever will direct oil to the multi- hydraulically applied and spring released
disc brake to apply the steering brakes. whereas the brake clutch packs are
The amount of brake application is spring-applied and hydraulically released.
proportional to the amount of lever If a hydraulic failure occurs or the engine
movement. When the machine is shut is stopped, the steering drive will
down, oil pressure is released from the automatically apply the brakes.
brake spring caging piston cavity and the When the steering levers are in the drive
brakes are automatically applied by position. the drive clutch pack is held
spring pressure. engaged and the brake clutch pack is
Terex steering brakes (the brakes applied held disengaged by hydraulic pressure.
to either track to aid in steering the Power to the tracks is transmitted from the
machine). it has just been seen, are ac- pinion shaft to the bevel gear and through
tivated by the same lever that disengages the engaged drive clutch pack to the out-
the clutches. The brakes also can be ap- put shaft and sprocket.
plied together by a brake pedal. The brake When a steering lever is moved to the
pedal also has another function. On the brake position. the hydraulic pressure to
initial part of its travel an engine the clutch packs on one side of the
decelerator pedal is simultaneously steering drive is released. As the pressure
depressed. decelerating the engine before drops. springs engage the brake clutch
the brakes are applied. Further movement pack and disengage the drive clutch
of the brake pedal applies both brakes to pack. The brake clutch pack then locks
slow or stop the machine when working the output shaft with the steering drive
on steep grades. housing. thereby stopping rotation of one
track chain. The machine can be stopped
BRAKE DISCS BEVEL GEAR by moving both steering levers to the
STEERING DISCS brake position.
When the foot brake is applied, hydraulic
SPLINED HUB oil pressure to troth brake clutch packs is
released. As the pressure drops. springs
engage both brakes simultaneously.
However. the hydraulic oil pressure to the
drive clutch packs is not released and the
torque converter slips. The toot brake will
hold the machine stationary with the
transmission in second or third gear but
not in first gear at high idle.

OUTPUT PINION SHAFT FOR TRANSMISSION INPUT PINION SHAFT

INITIAL FINAL REDUCTION

(6 -191) STANDARD STEERING UNIT

courtesy el leiernIreeal Harvester

431
6:138 TRACK MACHINE STEERING

Hydrostatic Drive Steering Controls Jaw Clutch Steering Controls

There are a number of variations in Jaw clutches on shovels and cranes are
hydrostatic drive steering controls. Basically. usually operated by electric.hydraulic, elec-
though. the controls use hydraulic pressure. tric-pneumatic (air). or straight hydraulic
either through a pilot controlled circuit or a cylinders. The propel brakes on these
direct controlled circuit. to modify the speed machines are generally spring-applied and air
or direction of rotation of the propel motors or hydraulically released.
for turning. Remember that brakes don't play
a part in steering hydrostatic drive crawlers Below are two examples of turning
because hydrostatic drive allows for com- procedures for machines using jaw clutches.
plete. continuous control of power flow to the the first for a large mining shovel and the
tracks. second for an excavator.

The operations of a steering stick and propel

pedals for a hydrostatically driven Caterpillar
excavator are described below. A lever moun-
ted between the travel pedals (Figure 6-192)
provides gradual pivot. or counter-rotational
steering. Depress the forward or reverse pedal
and move the lever toward the right or left:
one track drives and the other is slowed down
giving a gradual turn in the direction the lever
is pushed. Move the lever farther into contact
with a resistance bumper spring. one track
drives and the other locks giving a pivot turn.
Push the lever beyond the bumper spring and
tne locked track will counter rotate for a spot
turn.

BRAKES BRAKES
LEFT MOTOR RIGHT MOTOR

REVERSES REVERSES
LEFT MOTOR
r;
11 1%
1
I
RIGHT MOTOR
%

REVERSE it 1, 1 I FORWARD
PEDAL I
t...-,
I " PEDAL
ft,....;

..1 STEERING (1

LEVER

TRAVEL
PEDALS
(6-192)

Coisiesy of Caforpaiar Tractor Co

432
 TRACK MACHINE STEERING 6:139

Procedures To Forward Len Steer A

P & H Mining Shovel
Lett Steer: To turn left. the steering toggle
switch (Figure 6.193) must be in the left steer
position. Electric and pneumatic control
sequencing will engage the right male jaw
clutch and disengage the left male jaw clutch.
This same sequencing releases the right
propel brake and sets the left propel brake. To
ensure that the proper jaw clutch is engaged.
the operator should slowly move the ex
cavator by moving the controller handle in the
direction opposite the desired direction of
travel until the excavator has moved ap-
proximately one foot. The operator should
then slowly move the controller in the desired
direction of travel.

PROPEL . O O O
FORWARD I=E
"to

LEFT HAND
CONTROLLER
0
0.
FORWARD

A
40.-7RIGHT
BRAKE
RELEASED
LEFT .
BRAKE
SET

LEFT RIGHT
STEERING STEERING
CLUTCH CLUTCH
DISENGAGED ENGAGED

(6.193) LEFT STEER. FORWARD

Courtesy of Harnischfeger Corporation. P&H

-0
433
6:140 TRACK MACHINE STEERING

Steering Directions For A Note: The poppet valve is spring centered

Bucyrus Erie Excavator 0 hold it in a vertical position and
has detents to hold it in positions 2
A poppet type air valve on the side valve stand and 3.
(Figure 6-194) controls the steering of the
machine. This valve works in conjunction with To insure proper engaging and
the propel foot pedal. The valve has three disengaging of the steering clut-
positions: ches. the propel foot pedal should
be in neutral position when moving
1. Vertical allows for propelling straight the steering clutch valve to
forward or straight backward with the positions 2 or 3. However. the valve
propel foot pedal. handle can be returned to the
2. Push forward steer to the left by neutral position while propelling in
pushing down on the propel loot pedal. a turn. and the machine will then
The poppet air valve supplies air to set the propel in a straight direction.
right steering clutch and to release the Always return the poppet air valve
right digging brake. It also cuts off air handle to the vertical position
from the propel foot pedal leaving the left before starting to dig with
clutch spring released and the left brake machine.
spring set. The machine will then propel
around the locked left crawler belt.
3. Pull backward steer to the right by
pushing down on the propel foot pedal.
The action is the same as steering left ex-
cept that opposite clutches and brakes STEERING CLUTCHES
are used.

ENGINE CLUTCH

ENGINE THROTTLE
AIR PRESSURE
REGULATOR
WRIST
HOUSE LOCK
DIG

SWING

BOOM HOIST

PROPEL

MANUAL DIG CONTROL

_.......---- DIVERTING VALVE

(6-194)

Courtesy of Bucyrus Erie Co

 TRACK MACHINE STEERING 6:141

BASIC LUBRICATION AND COOLING The oil received by the flow divider (6) is
OF STEERING SYSTEMS divided equally between the brake boosters
(1). When the boosters are disengaged. oil
Most modern wet steering clutches and flows through a passage in the booster
brakes are lubricated and cooled by oil that is pistons and is dumped into the steering clutch
part of a larger reservoir system that also sup- compartments When the boosters are
plies oil to the torque converter. transmission. engaged. oil pressure is forced against the
and bevel gear compartment. This oil system
booster pistons. Two relief valves in-
will have one or more hydraulic pumps driven corporated in flow divider (6). prevent
from the back of the engine or by the torque pressure from becoming excessive and
converter impeller. Pumps can be single or damaging the brake mechanism.
double section models. Often the double sec-
tion models have a large section that delivers The valves in the steering clutch hydraulic
oil to the transmission and torque converter control valve (14) direct oil to the steering
and a smaller section that pumps oil to the clutch pistons (11) in the steering clutch hubs.
bevel gear and steering clutches and brakes. These pistons move to disengage the steering
clutches. If the valves should stick. the
A description of the circulation of oil through pressure relief valve unseats and the oil
the oil system that includes steering clutches bypasses the steering clutch hydraulic con-
is given below The numbers refer to Figure 6- trols. v n the steering clutches are engaged
195. oil flows around the control valves to the
OPERATION torque converter inlet relief valve (12). A small
amount of oil is bled off through an orifice to
3 4 lubricate the control valve operating
mechanism and the bevel gear and beve'1ear
shaft bearings. Oil supplied to the torque con-
verter inlet relief valve (12) charges the torque
converter portion of the torque divider com-
ponents. The scavenge pump (17) returns
leakage oil from the torque divider housing (8)
to the sump in the transmission case (16).
Discharge oil from the torque converter
passes through the torque converter oulet
relief valve (7) to the oil cooler (10) on the
=SUPPLY OIL IIII PRESSURE OP. right side of the diesel engine. From the
666 I. 6 =RETURN OIL CI LUBRICATION OIL cooler. oil returns to the transmission
(6-195) FLOW OF Oil. SCHEMATIC lubrication regulator valve (13) where a por-
Courtesy of Caterproar Tractor Co
tion of the oil is supplied to the transmission
lubricating system. Oil not used for trans-
mission lubrication is directed from the valve
Oil is picked up by the pump (15) from the (13) to the inlet of the hydraulic pump (4).
sump in the transmission case (16). Before en-
tering the pump. the oil is drawn through the
magnetic strainer (19). The oil. under pressure
from the pump. is forced through the oil filter
(18) to the flow control and relief valve (2). if
the filter is clogged. a bypass valve in the
filter housing allows oil to bypass the filter
element.
The flow control relief valve (2) separates the
flow of oil. directing some to the steering
clutch hydraulic control valve (14) and the rest
to the flow divider (6). If the oil flow becomes
restricted. the relief valve will open and allow
the oil to return to the torque converter inlet
relief valve (12).

435
6:142 TRACK MACHINE STEERING

QUESTIONS TRACK MACHINE STEERING 14. Briefly list the changes of motion that
take place in a hydrostatic pump and
1. List the four main steering systems used
motor.
on crawler machines and give an exam-
ple of the type of machine where each 15. On a machine that has manual or
would be found. booster-assisted controls, which of the
following combinations of the two clutch
2. Briefly explain how a steering clutch is levers and two brake pedals is used to
used to steer a crawler machine, make a pivot turn to the right?
3. What function do the brakes serve in (a) Both levers pulled back and left
crawler steering? brake applied.
4. What are two types of brakes used for (b) Left clutch lever pulled back and
crawler steering? right brake applied.
5. List the major parts that comprise a (c) Right clutch lever pulled back and
multi-disc clutch pack, left brake applied.
6. What advantages do wet clutches have (d) Right clutch lever pulled back and
over dry clutches? right brake applied.

7. How does a single speed planetary 16. Booster controls are used to
steering system differ from a basic (a) Give a faster release.
planetary? In a steering planetary what
combination of gears is used to transmit (b) Allow bigger clutches to be used.
power? (c) Reduce the effort needed for con-
trol.
8. By what mechanism is the sun gear held
in planetary steering? (d) Give smoother clutch operations.

9. What is the main advantage of two 17. On multi-disc clutches with hydraulic
speed planetary steering over single controls, what are the two combinations
speed planetary or multi-disc clutch used for clutch apply and release?
steering? 18. What is the function of a flow divider for
10. Why do shovels use jaw clutches for hydraulic brake boosters?
steering rather than multi-disc clutches 19. A machine with hydrostatic drive has
or planetaries? steering lever and
11. How is a machine with hydrostatic drive direction control pedals.
steered? 20. List the three types of power controls
12. Which is the most common pump-motor used for jaw clutches on modern shovels
combination used on crawler machines and cranes.
with hydrostatic drive? 21. Most modern crawlers with wet clutches
(a) Fixed displacement pump driving a and brakes share a common oil supply
fixed displacement motor. with:
(b) Variable displacement pump driving (a) Torque converter and final drive.
a fixed displacement motor. (b) Bevel gear compartment and final
(c) Fixed displacement pump driving a drive.
variable displacement motor. (c) Torque converter, transmission, and
(d) Variable displacement pump driving bevel gear compartment.
a variable displacement motor. (d) Torque converter, transmission, and
final drive compartment.
13. True or False, in a hydrostatic pump or
motor the swash plate rotates and the
circular block of pistons is held
stationary.

436
 TRACK MACHINE STEERING 6:143

MAINTENANCE, TROUBLE SHOOTING AND 4" FREE MOVEMENT

REPAIR ON SINGLE AND MULTI-DISC
AND PLANETARY STEERING i
)4
DAILY ROUTINE MAINTENANCE
Daily routine maintenance checks for steering
clutches and brakes is part of the Walk-
Around-Inspection of the machine. Like final
drives, steering clutches and brakes are en-
closed within a housing and therefore little
can be seen of them. However. there are
checks and adjustments (on some machines)
that can be made to ensure continued service:
1. Check the oil level on wet clutches (this A-6601
check point ;^^Iudes the brakes usage. MEASURING FREE MOVEMENT OF STEERING
and add oil 81 needed. Should a clutch CLUTCH LEVERS
require regular topping up, further checks (6-196)
should be made to find the reason. Keep Courtesy of International Hance Sler
in mind that most wet clutch units share a
common reservoir with a number of other To adjust the clutches, stop the engine and
components. Therefore, low oil in the find the adjusters. Some are located ex-
clutch doesn't necessarily mean the ternally but others are found inside the
problem is in the clutch; the trouble could steering clutch compartments. and the com-
be with one of the other components partment covers will have to be removed to
sharing the oil. get at them. Consulting the service manual.
adjust the clutch release bearing clearance to
2. Some machines require adjustments on give the correct dutch free travel. Figure 6-
clutches and brakes to compensate for 197 shows an internal clutch adjustment
normal running wear. As was seen in the being made.
discussion of crawler steering, there are
many different methods and controls for
steering. Therefore. it follows that there
are many ways of adjusting steering and
brake mechanisms. Some of the common
ones are covered here. ,..011111
Multi-Disc Clutches
(Manual Controls)
Manual controls have direct mechanical con-
nections between the levers and the clutches
and between the pedals and the brakes,
making adjustment fairly simple. The need for 4.
adjustment is determined by checking lever
travel on the clutch (Figure 6-196) and pedal
71474
travel on the brakes.
ADJUSTING STEERING CLUTCH
As the clutch multi-discs wear. the lever free
travel becomes less and less, finally reaching 2Adjusting screw. 3Locknut
a point where the release bearing is con- (6.197)
stantly riding. If the release bearing is left to Courtesy of Ceierpoter Tractor Co
ride, the bearing will be ruined and the clutch
will slip under load.

437
 6:144 TRACK MACHINE STEERING
3 free
govern....a
Band Brakes (Manual Controls)
When brake pedal free travel becomes ex-
cessive. brake bands require adjustment for 1,
efficient and safe operation. One manufac-
turer. for example, recommends adjusting t,
ti, '
when free travel exceeds three inches. (6-198)
STEERING BRAKES ADJUSTMENT

c)

®
110415 C

4) Courtesy of International Harvester

Multi-Disc Clutches, and Multi-Disc Brakes

00 0 (Full Hydraulic Controls)
Multi-disc clutches with full hydraulic controls
The type of adjustments vary with the
machine. Dry brakes, like the one in Figure 6- are non-adjustable. or self-compensating as
198. have two points to adjust. the brake band they are called No adjustment is needed be-
support screw (C) and the band adjusting bolt cause (1) they don't have a release bearing.
(E). having instead a piston and (2) the clutch
units are wet which reduces wear on the
Refer to the machine's service manual for the clutch plates.
number and location of brake adjusters. and
for the adjusting procedures. Note before ad- Like multi-disc clutches, multi-disc brakes are
justing brakes. always shut off the engine and also non-adjustable Thus a machine with
block the machine if it is not on level ground. hydraulically controlled multi-disc clutches
and brakes requires very little clutch and
Booster Aided Clutches and Brakes brake maintenance.
Booster assisted dry. multi-disc clutches and Band Brakes (Hydraulic Controls)
band brakes usually are adjusted in a manner
similar to manually controlled clutches and Like manually controlled dry band brakes.
brakes Check specific service manuals for hydraulically controlled wet band brakes
require adjustment. They are easy to adjust.
adjusting procedures.
as seen in the example in Figure 6-199.
'---..,, 41, L.

-. --Ari:
e".
I
I

t$w

.1
. 2 4# - . 40........
Woos

Check adjustment Adjust brakes To Adjust: 2 Turn adjusting screw in until

when pedal travel reaches 6 to 6- 1 Remove guard and cover tight Back screw out 1-11
1.2 inches (160 to 165 mm) turns.
(6-199) Courtesy 01 Catercorner TraciOr CO

438
 TRACK MACHINE STEERING 6:145

Planetary Steering and Braking Oil Service

(Single Disc)
Steering systems usually require some type of
Single disc planetary steering brakes and oil service at time intervals of 50 hours. 100
pivot brakes require periodic adjustment hours. 250 hours. 500 and 1000 hours. The ser-
When a steering brake drifts in one direction vice can be anything from changing filters to
under a heavy load. it's an indicator that the draining the complete system and (1) cleaning
brake is slipping and needs adjustment. Signs screens (2) changing filters (3) checking
that indicate the pivot brake needs adjust.rig screens. filters, and the sump for con-
are excessive pedal free travel or slipping of tamination (4) refilling. When you drain a
the brake on turns Access to the pivot ad- system be sure to have a large enough con-
juster is gained by removing a threaded plug tainer to take all the oil; some machines hold
from the side of the brake housing above the 65 gallons or more.
final drive case (Figure 6-200). Steering
brakes have similar access holes for ad-
just mer.t.

PIVOT BRAKE
ADJUSTING SCREW

()
LOW RANGE
ADJUSTING SCREW'

e .0
a.toite

CE-92202 CHECKING LOW AND HIGH RANGE

BRAKE ADJUSTMENTS WITH LOW RANGE
ADJUSTING SCREW
PIVOT AND LOW RANGE (6-200)
BRAKE ADJUSTMENTS Courtesy of Intemarional Harvester
Checking for contamination. as mentioned
SCHEDULED MAINTENANCE ON above, is a part of oil service. An example
STEERING SYSTEMS taken from a service manual of what con-
taminants to look for in a system that supplies
Scheduled Maintenance for steering clutches oil to steering clutches and brakes is given
and brakes includes' below:
1 adjustment checks and procedures (if ap- Iron or steel particles indicate possible
plicable) transmission. transfer gear or bevel
gear failure.
2 oil level checks. and oil service.
Bionze-cotored particles indicate a
Adjustments clutch failure. either a steering clutcl,
or transmission c'i h.
The clutch and brake adjustment checks
previously discussed can be included as part Bright steel particles in the filter in-
of a scheduled maintenance program. dicate a pump failure.
However. actual adjustments are made on an
as needed basis and will often be done as a Aluminum particles ind.cate a torque
result of the daily walk-around-inspection. converter failure.
Rubber particles indicate a blown seal
or ruptured hose.

439
6:146 TRACK MACHINE STEERING

Following are two examples of scheduled ser-

vice on Craw! r steering and braking.
Caterpillar D6 Crawler Dozer (only steering and braking service shown)

ITEM SERVICE

EVERY 10 SERVICE HOURS OR DAILY

I
o
.s.
ok
.s.
0
Z9Z044
44

(9) Transmission. bevel gear and Check oil level S3

steering clutch compartment

EVERY 250 SERVICE HOURS OR MONTHLY

.
(27) Steering clutch brakes Check adjusi if necessary 1
1

EVERY 1000 SERVICE HOURS OR 6 MONTHS

(33) Transmission. bevel gear and steering Change oil and breather S3
Clutch compartment wash suction screen

EVERY 2000 SERVICE HOURS OR 1 YEAR

(41) Brake control shalt bearings Lubricate 2 fittings MPG

(42) Steering clutch control lever bearings Lubricate 6 fittings MPG

Key to Lubricant
S3 Superior Lubricants (Series 3) only
rlY0 Superior Lubricants (Series 3) containing zinc dithiophosphate.MIL-L-2104A. MIL-L-21048 or
approved Industrial-type Hydraulic Oil
MPG -- Multipurpose -type Grease
MPL Multipurpose-type Lubricant.
Fiat-Allis Crawler Loader (only steering and braking service shown)
OCLEAN. CHECK ANDIOR ADJUST b HYDRAULIC CIRCUIT OIL OPRESSURE GUN LUBRICANT
OENGINE CRANKCASE OIL * REGULAR GEAR OIL
SERVICE NO. OF TYPE OF
INTERVAL DESCRIPTION OF SERVICE POINTS LUBRICANT
Each 10
hours Steering and brake linkage lubricate 4 D
or Daily
Each 100 hours
or 2 weeks Bevel gear. steering clutches and
(Also perform brakes -- check oil level 1
10 and 50 hour
services,
Each 500 hours
or 3 months
Brakes and steering clutches hydraulic 0
(Also perform 1
10. 50 and 250
system -- clean filler
hour services)
Each 1.000 hours
or 6 months
(Also perform
10, 50. 100. 250.
Bevel gear. steering clutches and
brakes change oil
*
and 500 hours
services . .
i.
o
 TRACK MACHINE STEERING 6:147

TROUBLESHOOTING ON STEERING Manually Controlled Clutches and Brakes

SYSTEMS
Manually operated clutches and brakes are
Introduction To Troubleshooting fairly straight forward. If the various linkages
operate freely. are lubricated and are adjusted
No mention has yet been made of trouble- to provide the correct free travel, then the
shooting as a service procedure. The reason
problem is internal and clutches and brakes
is that. generally speaking, troubleshooting
will have to be disassembled. Move. steer.
requires more experience and knowledge stop the machine: does this give you any
than most first year apprentices have and its clues? With the help of the service manual
therefore left to later training courses.
and an experienced journeyperson. list the
However. troubleshooting should be in-
possible causes of the problem in the order of
troduced in first year, and it is done so here in
relation with steering systems.
highest probability to the lowest before at-
tempting any service repair.
Troubleshooting is a systematic approach to
locating a problem in a machine. The em- Booster Controlled Clutches and Brakes
phasis in troubleshooting is on applying
systematic and sequential testing procedures Booster Con tro is:
to pinpoint a problem before attempting to t. If the booster controls are mechanical,
make repairs. This ordered approach is used they can be easily checked because their
in troubleshooting to limit total repair time. workings are external and usually require
The testing or checking procedures may seem only an adjustment.
time consuming. but in the long run they save
time. Too often time is wasted on a hit and 2. Hydraulic booster control problems will in-
miss approach. disassembling components volve some checking of valves and
that didn't have to be taken apart if require a knowledge and familiarity with
troubleshooting steps had been followed. the hydraulic unit.
Troubleshooting's slogan is "Test, don't
guess". Beyond the booster controls. the system is
basically the same as the manual clutches
The general rule in troubleshooting is to make and brakes.
the quickest and easiest tests first, and if
nothing is found there. to proceed to the more
difficult tests. Following this rule. the testing
sequence would be visual checks first. then
operational tests. and then instrument tests.
Troubleshooting differs from preventive main-
tenance in that its function is not to prevent a
problem: the problem already exists and
troubleshooting must find what's causing it. At
the same time. though. there is a similarity be-
tween the two types of service.
Troubleshooting the cause of minor problems.
can often prevent much bigger and more ex-
pensive ones down the line.
Troubleshooting expertise comes from a
thorough knowledge of the internal workings
of components combined with lots of ex-
perience. At this level of training you should
seek the help of a qualified mechanic when
troubleshooting. Also. some service manuals
list troubleshooting steps for different com-
ponents.

Troubleshooting Steering Systems

Different troubleshooting procedures are
required on the various steering systems.

441
 6:148 TRACK MACHINE STEERING

Full-Hydraulically Controlled Clutches and

Brakes
Clutches and brakes with full hydraulic con-
trols are probably the most complex to
troubleshoot. Again you need both knowledge
of how the units operate and service ex-
perience with them. The units are tested with
a hydraulic test box shown in Figure 6-201.

to;
P

.16-7re..L-4111111.,

Alit, ' 'ice

4 a4 .4

/MI 410

C
4
iimg
Dr
is

(6-201)
ON MACHINE PRESSURE TAP LOCATIONS
A Len steering clutch oil pressure tap 8Transmission oil pump pressure tap. CRight steering clutch
oil pressure tap. D-- transmission lubrication oil pressure tap.
Courtesy of Calerprilar Tractor Co

442
 TRACK MACHINE STEERING 6:149

The hydraulic test box can test the entire

power train hydraulic system. Lines from the
box are plugged Into pressure tap locations.
Readings are taken and compared to service
manual specifications. If a particular unit is
malfunctioning the manual will usually in-
dicate what the prcblem is and what the
causes are likely to be. The diagram below
(Figure 6-202; shows the pressure tap
locations (A. B. C. 0; for the steering clutches
as well as for the torque converter and trans-
mission.

FLYWHEEL CLUTCH, TRANSMISSION AND STEERING CLUTCH

HYDRAULIC TESTS

KtarylexcereAle-xx#21,.. Acco:ex:ex;..

10 11

9
(=SUPPLY OIL PRESSURE OIL
-ere.
X 0...1 1=IRETURN OIL , VA. LUBRICATING OIL

(6-202)
TRANSMISSION AND STEERING CLUTCH OIL SYSTEM SCHEMATIC
1 Magnetic strainer 2 Oil pump 3-011 filter 4Flywheel clutch housing. 5Transmission lubrication
regulator v,Ive 6 Relief valve (steering clutch hydraulic control) 7Steering clutch hydraulic control valve.
8 -Right steering clutch piston 9 -Transmission case 10-0d cooler. 11Screen ALeft Steering clutch oil
pressure tap B -Transmission oil pump pressure tap. C Right steering clutch oil pressure tap.
DTranSmission lubricating oil Pressure tap.
CourteSy of Caterpillar Tractor Co

443
6:150 TRACK MACHINE STEERING

Operational Checks For Steering Problems 4. Broken steering clutch spring retaining
bolts.
Below are checks that Caterpillar recom-
mends to troubleshoot steering problems on 5. Worn serrations on driving and driven
one of their machines having multidisc clut- steering clutch drums causing plates to
ches with contracting brake bands. "hang up ".
With the engine running. move the trans- Problem: Sluggish Steering
mission speed selector lever to all positions.
The detents should be felt in each position. Probable Cause
Operate the machine in all speeds. Listen for
unusual noises and determine their source. 1. Incorrectly adjusted. worn or broken
Lock the brakes and stall the torque converter linkage.
in each speed. If the universal joints turn, the 2. Worn brake lining.
transmission clutches are slipping. An
operational check list for steering problems 3. Low pump output.
follows.
4. Worn serrations on driving and driven
Problem: Machine Will Not Turn In One steering clutch drums causing plates to
Direction. hang up.

Probable Cause SERVICE REPAIR OF TRACK MACHINE

1. Steering control linkage incorrectly ad- STEERING
justed If troubleshooting procedures have indicated
2. Excessive leakage in circuit between con- an internal problem in a steering clutch(es). it
trol valve and steering clutch piston or be- will have to be removed. Removing a crawler
tween piston seals. tractors steering system is a major job,
although there is a trend in modern machines
3. Valve spool stuck or valve spool spring towards modular components which make the
weak or broken. removal easier. The job requires suitable
lifting equipment both for personal safety and
Problem: Machine Will Not Steer In Either for proper care of the component.
Direction.
There are some similarities common to most
Probable Cause steering systems that can be kept in mind
when removing any steering unit:
1. Low pump output.
Most steering systems have a common
2. Leakage in the lines between the oil supply and the oil has to be drained.
hydraulic system relief valve and the con-
trol valve. Steering units are all located in
relatively the same place at the rear
3. Excessive leakage in the transmission. of the tractor between the transmission
4. Hydraulic system relief valve set low or and the final drive.
leaking. Most machines require that the fuel
5. Incorrectly adjusted steering and brake tank. seat, hydraulic lines be removed
linkage. to gain access to the clutches.
Covers over the steering clutch com-
Problem: Machine Veers In Either Direction partments must be cleaned and
With Both Steering Clutches removed.
Engaged.
Removal procedures for dry clutches
Probable Cause are the same as for wet clutches (which
1. Incorrectly adjusted pedal linkage. most mode ni machines have) except
for the draining of oil.
2. Worn steering clutch plates.
Clean practices should be maintained
3. Weak or broken steering clutch springs. in removing all steering systems

444
 TRACK MACHINE STEERING 6:151

Points When Removing Steering Systems

I Steam clean or high pressure wash the
entire clutch housing area including the
related parts that have to be removed. If
equipment is not available the cleaning
will have to be done by hand. Clean the
parting laces of the housings and covers.
and clean the linings and lines before
removing them. Use a wire brush to
remove the bulk of the dirt and then use is

a bristle brush and solvent to complete 11 firrestikiria-:

the lob. !I -1°110NAL
2. Once the housing and surrounding area
;
is clean. drain the oil. Be sure you have a .
container large enough to hold all the oil.
Even though a multi-disc clutch and a 17/43'67-77.1_1`11"A"'----t
band brake. such as Caterpillar uses. CE-104115
can be removed without draining the oil. ert*IrTa1:11111
it is a good general rule to do so. Usually (6-203) REMOVING THE TANK AND SUPPORT
when a failure occurs the oil will be con- ASSEMBLY
taminaled and will have to be drained Courtesy of International Harvester
anyway. Note that any unit that has run in
contaminated oil will have to have the
inside of its housings and its screen
cleaned.
3. Some steering clutches can be removed
individually. but others must be removed
as an assembly. In either case the clut-
ches are disassembled after they are
removed.
4 When a fuel tank has to be removed. it is
not necessary to drain the tank because
it will have a shut off. Be sure to cap the
fuel line to prevent drain-back from the
fuel filters and to protect the system from (6-204)
dirt. The seat may be attached to or be Courtesy of Cateraitlar Tractor Co
part of the fuel tank and can be removed
at the same time. A sling, like the one in .

Figure 6-203. is suitable for lilting a tank. V' 0

AN
g

Place the removed tank in an upright 7 kri111-'

.
.4.-
,
.41

A..

position.

5 Once the fuel tank and seat are removed.

disconnect the various hoses and lines,
cap their ends and tag them for iden-
tification. Disconnect any linkage. unbolt
the cover(s) and with suitable lifting
equipment lift off the cover(s). Figure 6-
204 and 6.205 show two different cover
assemblies Cat has individual covers (6-205) REMOVING THE REAR MAIN FRAME
which serve as clutch covers and brake COVER
booster assembly housings. The In- Courtesy of International Harve.ger
ternational shown here has a main rear
frame cover: steering and brake controls
are mounted on top of it. The In-
ternational cover is much larger.

445
6:152 'RACK MACHINE STEERING

6. When lifting out the steering clutch. keep

the assembly level. because the clutch
may slide free of the outer drum (Figure
6-206).

..%.....,

*1
tt 9.f.

4-7
86. e 11: i-Cl&Nalp

(6-207) REMOVING THE STEERING DRIVE

11. # 8.
Courtesy of International Harvester

Terex also uses a modular system

s')
Vy Ark referred to as a reduction gearing
assembly. The output or quill shafts have
to be removed prior to !Ming out the
assembly. The shafts are removed by
taking off covers from the two ends of
A14164X1 the final drive pinion shafts. similar to the
fr
removal of the International output
(6-206) REMOVING STEERING CLUTCH shafts. The reduction gearing assembly
Courtesy of Caterpillar Tractor Co and transmission are removed together
and then disassembled (Figure 6-208).
7. Removing the planetary systems (In-
ternational Harvester Tractors) is a big TRANSMISSION SEALANT REDUCTION
lob on some machines because the ASSEMBLY SPACER GEARING
tracks have to be disconnected and the (IF USED) ASS MBLY
final drives disassembled to get the
pinion shaft out. The job is not as big on
machines where the pinion shafts can be
slid out by removing (1) a segment from
the sprocket and (2) a cover over the
pimon shaft outer Support bearing in the
final drive case.
International has recently manufactured
a modular steering system that allows OUTPUT SHAFT BOLT & LOCKWASHER
the clutches. brakes. bevel gear and
drive pinions to come out as a unit. (6-208) PS.01167
Provisson is made to remove the output
REMOVING AND INSTALLING REDUCTION
shafts from the steering drive assembly. GEARING ASSEMBLY
and once the mounting bolts and various
hydraulic lines are disconnected the Courtesy of Terex General Motors Corporation
assembly can be lift out (Figure 6.207).

Points On Disassembling and Repairing

Steering Clutches
1. As was discussed earlier, there are
basically two types of clutch packs: (1)
spring-applied, manually or hydraulically
released, and (2) hydraulically applied.
spring or natural release. Spring-applied

446
 TRACK MACHINE STEERING 6:153

clutches must have their springs com- 2. Inspect the brake band: 4 may require
pressed before they can be disassem- relining.
bled. The clutches are set into a steering
clutch stand (Figure 6-209) or blocked. 3. A measurement is taken of the clutch
and then disassembled with the aid of a pack to determine its remaining service
compressor tool or a hydraulic press. life. The distance "A" (the stacked
height) in Figure 6-210 is taken and com-
pared to minimal standards in the service
manual. Even if the clutch pack is within
specifications, the discs should be
checked for warping or wear on the
splines. Keep the discs in the same or-
der. Note that individual discs are not
usually replaced on clutch packs, rather
the pack is replaced as a whole.

9 10 11 12

17976X2

(6-209) STEERING CLUTCH STAND

Courtesy of Caterpillar Tractor Co.

Mir

T 41701 13 14 (6-210) 15
CROSS-SECTION OF STEERING CLUTCH
ASSEMBLY
9Disc Assembly. 10Sleeve. 11Inner Spring.
12Disc. 13Retainer. 14Outer Spring.
15Inner drum. ADimension to be checked.
Courtesy of Caterpillar Ttaelor CO
T 411117
4. Make the following inspections:
(6-209)
(a) Check the splines on the inside of
COMPRESSING STEERING CLUTCH SPRINGS the brake drum and the outside of
Courtesy of Cateroinar Tractor Co the drive hub, and replace ihem if
thay are worn.
(b) The outside of the brake drum can
be turned on a lathe. Since turning
requires a special lathe and an ex-
perienced hand. the drums are
usually sent out to be done. The im-
portant point to remember about
turning drums is to be sure that they
can be turned by checking minimal
drum thickness requirements in the
service manual. Don't make down-
time longer by sending out drums
411122 that are worn too thin to be turned.
(6-209) STEERING CLUTCH SPRING COMPRESSOR
TOOL
Courtesy of Catefoillar Tractor Co

447
 6:154 TRACK MACHINE STEERING

(c) Remove springs (Figure 6-211) and (b) Hydraulically released: the piston in
check them for cracks, free height the clutch hub should be removed,
and compressed height (see service the bore checked and the seal
manual). replaced. The piston can be pulled
from the hub with a two-jaw puller
using reverse jaws.
6. Hydraulically applied clutches and
brakes are generally found on modular
steering systems. Unlike the previously
discussed spring-applied clutches which
could be repaired in the field, hydraulic
applied clutches are usually disassem-
I bled and repaired in a shop. Special
A C._
tools and a clean place to lay out the
numerous parts are necessary when
overhauling one of these units. Once it's

I MIA 5
i apart. the kinds of repairs required on a
hydraulically applied clutch pack are
similar to the repairs on a spring-applied
(6-211) clutch pack.
1Adapters 2Sleeve. 3Spring. 4Spring.
5Retainer. 7. One repair that may be needed on large
Courtesy of Caterpillar Tractor Co tractors with two speed single disc
planetaries and caliper brakes is to
5. Check the clutch controls: replace the linings on the caliper brake
shoes. This job can be done without
(a) Manual: the release bearing and its draining the oil. The rear main cover is
related parts release pin removed to get at the brake assemblies
bushings, pivot bushings, release and they're removed from the machines.
collar thrust bearing (Figure 6-212) Figure 6-213 illustrates removing the
must be inspected and replaced

/
caliper shoes with a mallet and drift.
(if necessary).
.

PIVOT BRAKE
FORK :BRAKE FORK
BRACKET

RELEASE
FORK

RELEASE PIN N
RELEASE BUSHINGS FORK PIN
(OUTER)
COLLAR emme,maji-FORK PIN
WA-.1712A (CENTER)
RELEASE FORK (6-213) REMOVING THE PIVOT BRAKE FORK
PIVOT
Courtesy of International Harvester
A-32626

(6-212) RELEASE FORK

Courtesy of Internalonal Harvester

',448
 TRACK MACHINE STEERING 6:155

PIVOT BRAKE
SHOE PIN PIVOT BRAKE

BRAKE SHOE
GUIDE PIN

PIVOT BRAKE
WA3M/ SHOES

(6.213) REMOVING THE PIVOT BRAKE SHOES

Courtesy 01 International Harvesler

As was mentioned earlier. any problems

within the planetary gears require that
the oil be drained and the whole
planetary assembly be removed. Service
repair on a planetary would be carried
out in the same way as that for any gear
component (see the service points
discussed for final drive gears). Consult
the service manual for planetary service
repair procedures.

449
6:156 TRACK MACHINE STEERING

QUESTIONS CRAWLER STEERING

MAINTENANCE AND REPAIR
1. On a particular machine the oil supply
for wet. multi-disc clutches needs
frequent topping up. Does this indicate a
problem with the clutches?
2. What adjustments are required for the
clutches and brakes on a current
machine that has full-hydraulic con-
trolled multi-disc wet clutches and band
brakes?
3. There are two types of steering and pivot
brakes on planetary steering systems:
single-disc and multidisc. Do they
require adjustment?
4. Briefly describe the term trouble-
shooting.
5. What instrument is used to test hydraulic
steering controls?
6. When overhauling a multi-disc clutch
assembly. what method is used to deter-
mine the service life left in the discs?
7. Spring applied. multi-disc steering clut-
ches have to have their springs
with a
before they can be
disassembled.
8. List the other things that should be
checked on a multi-disc clutch at the
same time that the stack of discs is
measured.
9. For what reasons is it recommended to
overhaul modular steering systems in a
work shop and not in the field?

450
 TRACK MACHINE STEERING 6:157

ANSWERS TRACK MACHINE STEERING 9. On single speed planetary and multi-disc

clutch steering. power is cut to one track
1. Multi-disc clutch crawler loaders or on turns. Two speed planetary steering
dozers
has the advantage that power can be
Planetary gear crawler loaders or transmitted to both tracks (one track in
dozers high. the other in low) during a gradual
Jaw clutch shovels. log loaders. turn.
cranes 10. Since travel distances for shovels is
Hydrostatic excavators and other generally short, their movements slow
hydraulic propel machines and turns few, they can use the simpler
jaw clutch for steering.
Disengaging a steering clutch interrupts
the power to one track. With power cut to 11. Machines with hydrostatic drive have
one track. the driven track turns the separate power controls for each track.
machine toward the side with no power. The machine is turned by reducing the
power to one track; the more it's reduced
3. The brakes can be independently applied
to retard or stop the movement of the the faster is the turn.
drive shaft that leads to the sprocket and 12. (d) Variable displacement pump driving
tracks. preventing the track from moving a variable displacement motor.
freely with the momentum of the
machine. When a clutch-brake turn is 13. False. The block of pistons rotate and the
made. the machine can make anything swash plate is stationary.
from a gradual turn to a sharp turn 14. Rotary motion at the input drive shaft -to-
depending on the amount of brake ap- reciprocal motion of pump pistons -to-
plication. hydraulic pressure -to-reciprocal motion
4. Band brakes of motor pistons -to- rotary motion of out-
put shaft.
Multi-disc brakes
15. (d) Right clutch lever pulled back and
5. . A splined inner drum (the drive mem- right brake applied.
ber)
16. (c) Reduce the effort needed for con-
A splined outer drum (the driven mem- trol.
ber)
A set of alternating internally and ex- 17. Spring apply. hydraulic release
ternally splined discs Hydraulic apply, spring release
6. Wet clutches engage more smoothly 18. The flow divider directs the flow of oil
than dry clutches. run cooler and last equally between both boosters so that
longer. when one brake booster is being applied
A basic planetary has a ring gear around there is still full pressure available at the
7.
other.
the outside of the planet carrier. A
steering planetary has no ring gear, but 19. ... one ... two .. .
instead uses the sprocket drive pinion
shaft gear which runs on the inside of the 20. Electric Hydraulic.
planet carriers. Electric Pneumatic.
To transmit power. the sun is held. the Straight Hydraulic.
carrier is p swered. and the sprocket
21. (c) Torque converter, transmission. and
drive pinion v,aft gear is driven.
bevel gear compartment.
8. A steering brake holds the sun gear.
(Note that the steering brake can be
called a clutch brake. a clutch control or
a clutch.)

451
6:158 TRACK MACHINE STEERING

ANSWERS CRAWLER STEERING

MAINTENANCE AND REPAIR
1. Not necessarily. The clutches share a
common oil supply with other com-
ponents and the trouble could be with
one of these.
2. The clutches require no adjustment be-
cause they are self-compensating. The
brakes require periodic adjustment.
3. Single-disc do. but multi-disc don't.
4. Troubleshooting is applying systematic.
sequential testing procedures to pinpoint
a problem before attempting to make
repairs.
5. A hydraulic test box.
6. Measure the height of the stack of discs
and compare the measurement to the
specifications in the service manual.
7. ... compressed .. compressor
tool ....
8. Check:
Splines for wear inside of the brake
drum and outside of the drive hub.
Steel discs for warping. scores and
worn splines.
Springs for cracks. free height and
compressed height.
Wear on outside of the brake drum.
9. Lack of adequate cleaning equipment.
Complexity of disassembly and
assembly requires a clean work area.
Need for special tools.

...

452
 TRACK MACHINE STEERING 6:159

TASKS TRACK MULTIDISC

STEERING SYSTEM

ROUTINE MAINTENANCE CHECKS

Start a machine with multi-disc steering and
operate the clutch and brake controls. Make
any necessary adjustments. Report any more
serious malfunctioning to a journeyperson.

SCHEDULED MAINTENANCE CHECKS

Following procedures from the service
manual:
1. Remove and clean the oil filter housings.
2. Install new filters and gaskets.
3. Remove and clean screens and magnetic
filter (if equipped).
4. Top up the oil level and run the engine to
ensure there are no leaks.

TROUBLESHOOTING
If a machine is available with a clutch or
brake problem. under the assistance of a jour -
neyperson, perform troubleshooting
procedures outlined in the service manual to
locate the problem.

SERVICE REPAIR
Using the correct tools. equipment and
procedures as outlined in the service manual:
1. Clean and remove the housing cover and
remove the steering clutch and steering
brake unit of a crawler loadi or dozer.
2. Disassemble. clean. inspect the clutch
and brake parts for wear and damage.
Writ', a service report and pa^ "at, and
repair or replace parts that E..: t ser-
viceable.
3. Reassemble the steering clutch and the
steering brake.
4. Install and adjust (if applicable) the brake
and clutch.
5. Check the dive train hydraulic oil level
and fill to the required level with the
recommended oil. Change the filter (if
equipped).
6. Test V : . in of the brake and clutch
cont si Ispect the unit to ensure it
has :. .

453
 BLOCK

Wheel Machine
Suspension

454
 WHEEL MACHINES 6:161

WHEEL gACHINE SUSPENSION Spring Suspension on the other hand, is

used primarily on faster moving vehicles such
PURPOSE OF WHEEL SUSPENSION as trucks. Springs or other cushioning
devices are fastened between the axle
On wheeled vehicles the term suspension housings and the frame. They support the
refers to the frame and alt the components at- vehicles weight and at the same time permit
tached to the frame that support the machine. an independent up and down movement of the
The purpose of suspension is to: wheels and axle housings as the wheels en-
1. Support the machine including the power counter irregularities in the road. Spring
train components that drive the machine. suspension also provides a smooth ride for
the operator and reduces shock loads nn the
2. Support the steering axles (on some frame and frame components.
machines).
3. Provide a cushion to absorb shocks be- RIGID SUSPENSION
tween the wheels and the load (on
machines with springs or suspension Wheel Loader
cylinders).
Figure 6-213 shows a four wheel drive louder
4. Provide floatation. with rigid suspension and articulated frames.
Figure 6-214 shows a typical articulated
Although there are a number of different loader frame assembly. The loader's main
suspension systems. they can be divided into frame consists of a front and a rear section
two general categor;es: connected together by a pin and bearing
Rigid suspension. assembly.
Spring suspension

Rigid Suspension is gerarally found on

slow moving equipment such as graders.
loaders. skidders and farm tractors. This
suspension has no resilience other than the
flexing of the tires. Shock loads are imposed
directly on the frame and frame components.
Rigid suspension gives machines good
stability while travelling over rough terrain.

Courtesy of Terex. General Motors Corporation

455
r

6:162 WHEEL MACHINES

1 Grille
2 Main Irame rear section.
3. Main Irame -- front section.
4 Ladder.
5. Handrail
6. Frame locking bar MOM
6
7. _(.4ster Courtesy o International Harvester
(6-214) MAIN FRAME ASSEMBLY
Each main frame has many smaller sections which is attached to the rear frame section at
welded to it and is called a fabricated frame two points by pins and bushings. The purpose
assembly. This particular model has a grill of the bolster is to allow an up and down see-
bolted or welded to the rear section. Note the saw movement (oscillation of the rear axle in
frame locking bar (6) used to lock the two order to give full wheel contact with the
frame halves together when the tractor is ser- ground when the machine is working uneven
viced or transported. terrain (Figure 6-216). This rigid suspension
system used by wheel loaders gives the
To complete the suspension assembly. one machine more strength and stability than
axle (Figure 6-215) is bolted to the front frame could be obtained from spring suspension.
section. and one is bolted to a bolster or as
ifs sometimes called. a walking beam (7).

REAR HOUSING
PIVOT POINT
.0.-- ---....
FRONT HOUSING

BOLSTER

UP & DOWN MOVEMENT

(6-215)
0,
Courtesy of Clarke Equipment Company

456

I
 WHEEL MACHINES 6:163

61116'

/4 it
w.Lt11:1".4v NI,
(6-216)
Courtesy 01 Terex. General Motors Corporation
An alternate system to the bolster for axle
oscillation is an oscillating trunnion (Figure 6-
217) used by Caterpillar, The large trunnion
extends from the articulation hinge into the
rear frame and is supported by two tapered
roller bearings. The trunnion allows the
frames to move independently of one another
and still be hinged for steering.

1,4

(6.217) (6.217)
Courtesy of Caterpillar Tractor Co. Courtesy of Calerpillar Tractor Co.

1, 457
6:164 WHEEL MACHINES

Skidder
Like the frame on a loader, a skidder frame
(Figure 6-218) is made of fabricated steel and
is joined by a pin(s) and bushing(s) at the
hinge point between the two frames. However,
the skidder differs from the loader in that the
long section with the engine and transmission
is forward and the short section is at the back.
Also. the bolster or walking beam on a skidder
is attached to the front frame.

Counesy 01 Internatsonat Harvester

(6-218)

458
 WHEEL MACHINES 6:165

Loader Backhoes Motor Grader

Machines that have either front or rear axle Motor graders are yet another machine that
steering. such as a loader backhoe. also have uses rigid suspension. The frame (2, Figure 6-
rigid suspension. Loader backhoes vary in 220) is the back bone of the grader. It consists
size from small agriculture tractors with of twct cross-braced members that join near
loader backhoe attachments to much larger. the middle of the frame to form a single ar-
heavier machines made specifically for ched beam that runs to the front axle (1). The
backhoeing. Loader backhoes generally have two cross-braced members support the
two wheel drive and front axle steering. engine and power train components. The tan-
dem wheel assemblies (9) (one on each side
Loader backhoe frames are made of one of the rear frame section for four wheel drive)
piece fabricated steel. The power train and are attached to the final drive (8) so that the
drive axle are rigidly bolted to the rear of the assemblies pivot at the center point. Thus the
frame. The front axle is attached to the center drive wheels can oscillate parallel to the main
of the main frame by a pin and bushing frame giving the wheels good ground contact
arrangement at the middle of the axle. Thus in rough terrain. The tandem assemblies and
the axle has a pivot point (6.219) that allows final drives are attached to the main frame by
UP and down oscillating movement of the the final drive saddles (10).
wheels similar to that provided by the bolster
assembly on articulated machines.

'It

3 (6-219)
AGRICULTURE TRACTOR
FRONT AXLE PIVOTS
AT THE CENTER
Courtesy 0 J1Case

6 b 11

10

8 (6-220)
7
Courtesy of Champion Road Machinery Limited

459
6:166 WHEEL MACHINES

The front axle assembly of the grader is at-

tached to the main frame at the center with a
Din and bushing arrangement that allows it to
oscillate. Stops limit the amount of vertical
movement of the wheels (Figure 6-221)

'6 -221)
Courtesy N Champion Road Machinery Limited
(6-222)
The grader front axle is the steering axle Courtesy A Champion Road Machinery Limited
Besiecs turning, grader wheels an also lilt. a
feature that improves handling on rough
ground and gives sharper turns. Note in
Figure 6-221 that. although the axle is
oscillated the wheeis are perpendicular; they
have been tilted to offset the angle of
oscillation. Grader steering is discussed in
greater detail further on in this section.
A number of manufacturers now offer. as an
option. an articulated grader frame (Figure 6- ARTICULATED TURN
222). The frame is basically the same as the
one described above but with a pivot point (6-223)
part way down the rear section. The ar- Courtesy 01 Cateroltor Tractor Co
ticulated frame is used in combination with
front axle steering to improve the machine's
manoeuverability (Figure 6-223). Suspension
-,/
so°

mounting is the same as on the single frame

models.

SPRING SUSPENSION

Frame
A spring suspension frame. like a rigid
suspension frame. is the backbone of the
vehicle. All other suspension parts are at-
tached to it. Truck frames are constructed of
basically two parts: side rafts and cross mem-
bers The rails carry the load and the cross
members stabilize the rags. The entire frame
must be stiff enough to support the load it
carries. yet it must be flexible enough to ab-
sorb and distribute the stress placed on it.
Figure 6-224 shows a typical on-nighway truck
frame.

400
 WHEEL. MACHINES 6:167

REAR AXLE
CROSS MEMBER
(REAR)
REAR AXLE
CROSS MEMBER
(FWD) .

REAR CAB SUPPORT

..-4110%. -

REAR ENGINE SUPPORT

FRAME EXTENSION. R.H

FRONT CAB SUPPORT

FRONT ENGINE SUPPORT -0---STEERING GEAR BOX

FRONT SPRING SHACKLE

BRACKET

"UNDER BELL HOUSING CROSS

MEMBER

FRAME EXTENSION. L.H.

410
Courtesy of KenwOrth Truck Co
L._
(6-224) TYPICAL CONVENTIONAL FRAME
Frames can be channel. box or I -beam shaped
CHANNEL (Figure 6-225). Box construction is seldom
usea for truck frames. although some large
off-highway trucks may use a fabricated box
design. Highway trucks use channel frame
construction. single or double rail (two Chan-
nels together. one inside the other); the single
BOX
can be steel or an aluminum alloy, the double
is always steel. Aluminum is common when
light weight is desired. Large off-highway
trucks generally use the Ibeam frame con
struction.
t&N,
IBEAM w41%

(6-225)

Figure 6-226 shows a typical off-highway

dump truck frame. Cylindrical torque tubes
are welded to the I -beams at stress points for
support, and in some cases they are used as
mounting brackets. The front bumper on this
(6-226)
particular frame is welded to the front I-beams
Courtesy of Tore* General Motors Corporation and serves as the front cross member.

461
 6:168 WHEEL MACHINES

TYPES OF SPRING SUSPENSION The rate is the weight required to deflect a

spring 2.54 cm (1 inch). If the rate of deflec-
Because axles are bolted to the frames. rigid tion is constant. it is called a constant-rate
suspension systems have very little spring. For example. on a constant rate
resilience. On The other hand. spring suspen- spring. if 227kg (500 lbs.) deflects the spring
sion systems have good resilience because assembly 2.54 cm (1 inch), then 554 kg (1000
springs allow axles to move independently of lbs.) would deflect the same spring assembly
the frame. Springs reduce the shocks on the
5.08 cm (2 inches). Springs that do not deflect
frame and frame components, thereby at a constant rate are called vari-rate or
providing a smoother ride. progressive rate springs.
Trucks use several types of spring suspen- A leaf spring assembly is made of a series of
sion, depending on the size of the truck and flat spring steel pieces called leaves. Starting
the kind of work it will be doing. Common with one or two long leaves called main
types of spring suspensions are: leaves. the spring is built up with
1 Springs Leaf progressively shorter leaves. The number of
Coil 'eaves, their width, thickness and length will
Torsion Bar depend on where the spring will be used. The
leaves are drilled at their centers and are held
2. Rubber together by a special bolt called a center bolt.
3. Hydro Air Clips are placed along the leaves on either
side of the center bolt to keep the leaves
4. Air aligned. If one main leaf is used. its ends are
rolled to form an eye to hold a bushing and
SPRINGS provide a means of attaching the spring to the
frame. If two main leaves are used the second
There are three basic types of springs: leaf, will often have an eye rolled around the first to
coil. and torsion bar. Coil and torsion bar give it extra support (Figure 6-227). New
strings are found mainly on automobiles and leaves are made with a slight curve or arc
light duty vehicles. The discussion here is which allows the spring to flatten as the load
concerned with leaf springs which are used is pressed on it.
on light and heavy duty trucks.
Degree of hardness is an important charac-
teristic of leaf springs. A spring must be stiff
EYE
enough to carry the load yet be soft enough
when the vehicle is unloaded to give a good
ride. The stiffness of a spring is called its rate. CLIP

(6-227)

FRONT MOUNTING BRACKET FRAME REAR MOUNTING BRACKET

-11-- FRONT

) ..1--' -a
.0 0
BUMPER
0,, ../

z..k
----- SPRING SHOCK ABSORBER
% .
I ft,
..r.......
t._ _ --....,
EYE-BOLT SPACER SHACKLE LINK
TOW EYE-.1
AXLE A4051

U.B-OLT
1
(6-228) Courtesy 0 General Motors Corporation

462
 WHEEL MACHINES 6:169

Figure 6-228 shows the installation of a typical Auxiliary Springs

constant rate front spring. The spring is mou-
ted to the axle with U-bolts, nuts and lock Auxiliary or overload springs are leaf spring
washers The front end of the spring is moun- assemblies usually mounted on top of the rear
ted to a stationary bracket while the rear end spring assemblies. Auxiliary springs come
of the spring is mounted to a spring shackle. into action only when the vehicle is under
The shackle allows for variations in spring heavy load The auxiliary spring takes part of
length during compression and rebound of the the load by contacting special brackets at-
spring The center boll as well as holding the tached to the frame rail sides (Figure 6.230)
springs together. has another important func- when the load on the rear springs reaches an
tion: the head of the center bolt tits into a hole overload point.
in the axle or spacer to keep the axle square AUXILIARY SPRING BRACKETS
with the frame.
lni i
Progressive (Van-rate) Springs I----- ,1 --_ = r`,
4b.------.="1.1.__: .1' '------------'1H- JO

Progressiv (veri-rate) springs are leaf spring

assemblies with a variable deflection rate ob-
_.-.-m--__
----- I
REAR SPRING Y
_----
,:-
-'
,---_ -- ----
i
AUXILIARY SPRING
V,

tained by changing the effective length of the

U-BOLTS
spring assembly (Figure 6-229). The length is
varied by using a cam bracket at the rear of (6-230) TYPICAL AUXILIARY SPRING
the spring. As the spring assembly delects.
the point of contact on the bracket moves land -1 Axle Springs
toward the center of the spring assembly
thereby shortening the effective length and To increase the carrying capacity and to
making the spring stiffer. The spring provide more driving power. an extra axle and
movement inside the bracket is called slipper set of springs may be added to a truck. This
action. Var;-rate spring assemblies have addition is called a tandem axle and its
another progressively stiffening feature in that suspension is referred to as tandem axle
the ends of a leaf don't contact the leaf above suspension A tandem axle permits the truck
it when unloaded. As the spring assembly to carry heavier loads because the load is
deflects. the ends of the leaves make contact distributed over a greater number of axles.
giving increased stiffness. springs and tires.

EFFECTIVE LENGTH EFFECTIVE LENGTH

SLIPPER
CAM BRACKET
ACTION
LOADED
UN-LOADED (6-229)
(6-229) Courtesy of loternatronal Harvester
Councsy of International Harvester A number of manufacturers specialize in
building single and tandem axle suspension
Both constant and progressive rate springs assemblies. and these assemblies are referred
are used for front suspensions. but generally to by the manufacturers name. For example.
progressive rate springs are used for rear Hendrickson. Rockwell and Reyco are a few
suspensions because they provide a softer of the common suspension assemblies. Truck
spring when the vehicle is unloaded and a manufacturers often give a buyer an option as
stiffer spring when the vehicle is loaded. to what type (or manufacturer) of suspension
he wants. Thus. even though two trucks have
different names. e.g.. Kenworth. White.
G.M.C.. Ford. etc.. they could have the same
suspension. On the other hand. some truck
manufacture's such as Mack build their own
suspension assemblies and these assemblies

463
6:170 WHEEL MACHINES

are referred to by the name of the truck Another type of single-axle, leaf spring assem-
manufacturer. bly (Figure 6-232) uses a torque rod rather
than an eye and pin to attach the spring to the
Rear Suspension frame brackets. This particular assembly also
has an auxiliary spring.
Front suspension on trucks is almost always
leaf spring and is quite similar from truck to TANDEM DRIVE SUSPENSION
truck. However, differences do occur in rear
suspension. Tandem drive axles require a special suspen-
sion which will hold the axle housings in line
Single Axle Rear Suspension with one another and with the frame and will
allow independent oscillation of each wheel
Figure 6-231 shows a typical single-axle. leaf or axle housing. Tandem axle suspension
spring rear suspension. The spring has a must withstand rugged usage and give long
single eye and a slipper on the rear. A pin at- service life. Several types of tandem suspen-
taches the eye to a bracket on the frame. and sions are discussed below.
maintains axle alignment.
ift* :57-7-17r17-idarivace.
:

- 0,2
4 - 41.-t

4 (6-231)
Courtesy of Mac% Truck Limited
FROM .
AUXILIARY SPRING AUXILIARY SPRING
FRONT BRACKET REAR BRACKET

AUXILIARY SPRING
REAR SPRING
REAR SPRING REAR BRACK:T
FRONT BRACKET

TORQUE ROD FRONT

f
MOUNTING BRACKET REBOUND BOLT

TORQUE ROD REAR

00
MOUNTING BRACKET

ZA, SHIM- INSTALL:

Thick Edge Forwocd-4° Pinion Angie
Thin Edge Forward -6' Pinion Angle
SPRING ASSEMBLY Not Wed With 3° Pinion Angie
BOLT
TORQUE ROD U.BOLT SPACER
U.BOLT
ASSEMBLY
REAR AXLE
V-11"."*.UBOLT NUT
Courtesy of General Motors Corporation ASSEMBLY

SPRING ANCHOR PLATE T.4122

(6 -232)

464
 WHEEL MACHINES 6:171

Equalizer Beam Leaf Spring on highway trucks, although it is also found

Suspension (Hendrickson) on some off-highway logging trucks. The
springs are mounted on saddle assemblies
Equalizing beam suspension is available with above the equalizer beams and are pivoted at
leaf springs. rubber springs or air bags for the front end on spring pins and brackets. The
tandem drive assemblies. rear ends of the springs have no rigid at-
The most common type of equalizing beam tachment to the spring brackets, but are free
suspension is a leaf spring assembly made by to move forward and backwards in a slipper
Hendrickson illustrated in Figures 6-233 and action to compensate for spring deflection.
6-234 This type of suspension is mainly used Equalizer beam, leaf spring suspension is
made in various load carrying capacities.
SPRING BRACKETS
ATTACHED TO FRAME
TORQUE ARMS All

ryv
CROSS SUPPORT
TUBE

.4--EQUA'.IZING BEAMS
..41411%.
(6-233) Courfee., of Hendrickson Manufacturing Ltd

TORQUE
ROO

roRolIE
ROO

(6-234) f(

Courtesy of Hendrickson Manufacturing :td

e-
465
6:172 WHEEL MACHINES

Note the following points in installation of the Four-Spring Tandem Suspension (Reyco)
equalizer beam. leaf spring suspension:
The Reyco suspension in Figure 6-236 is a
The end of the cross support tube goes four-spring tandem suspension mainly used
inside the saddle clamp. for on-highway work. As in any conventional
tandem suspension, the leaf spring assem-
The equalizer beams are mounted blies carry the axles. The springs are mounted
below the axles. lowering the center of at three different locations on each side of the
gravity and giving good stability. chassis and thus distribute the load over a
Torque arms are used for suspension large area of the frame rail.
alignment and stability.
Reyco suspension differs from other types of
Ail mountings have rubber bushings four-spring suspension such as Dayton in that
and therefore only the spring eye pin at it uses torque leaves (5. in Figure 6-236) rather
the front of each spring requires than torque rods to maintain suspension
lubrication. alignment and stability. Torque leaves provide
Stability by minimizing axle wind-up caused
Equalizing beam suspension uses the by .;.:.01ine torque. and by load transfer
lever principtes to reduce bumps by 50 during braking. Reyco suspension is aligned
percent ror example. if the wheel rises by adjusting eccentric bushings (6) located at
six Niches going over a bump the load the torque leaf mounting eyes.
will only raise three inches (Figure 6-
235).

(6-235)
Courtesy 0 Hendrickson Manufacturing Ltd.

9 9 14 9

10 11 12 3 13 12 11

5 V.1 7 $ 3

FRONT

1 UBolt Nut and Washer 6 Eccentric Adiustmer 10 Spring

2 Bottom Plate 7 Radius Leal lye Bolt 11 Spring U -Bolts
3 Axle Housing 8 Rebound Bolt 12 U-Boll Spacer
4 Spring Sestt 9 Spring Hancer 13 Equalizer Arm
5 Radius Lea* 14 Equalizer Pivot Bolt

(6-236) Courtesy of General Motors Corporation

463
 WHEEL MACHINES 6:173

TRUNNION SHAFT
FRAME MOUNTING
BRACKETS

mad,
7,?-;;'-e

SPRING STRIKER
PLATES
TORQUE RODS (6)

SPRING SADDLE

(6-237)
N
Rockwell Leaf Spring Tandem Suspension Courtesy of Rockwell international Automotive Operations

On the Rockwell suspension in Figure 6-237, Oscillation of the springs and saddles on the
the load is equalized between the axles by trunnion (Figure 6-238) permit indeperdent
two full-floating leaf springs. The springs rest movement of he wheels and housings similar
at their outer ends on wear pads on the tops to the equalizing beam suspension. Trans-
of the axle housings and are mounted on verse (sideways) movement of the axles is
spring saddles by U-bolts at their centers. The prevented by the spring striker plates welded
springs and saddles are attached to, but free on the axle housings.
to oscillate on. a center member called a trun-
nion shaft The trunnion shaft is essenhally a Driving and braking forces are transmitted
dead axle attached to the frame mounting from the suspension to the chassis by a
brackets When a load is applied to the parallel torque rod system which also main-
venicle. force is applied in sequence to the tains the correct vertical position of the
frame brackets. the trunnion shaft, the spring driving axles and prevents weight transfer be-
saddles. the springs. ane finally to the axle tween tie axles. On the model shown in
housings and wheels, Figure 6-237 there are four torque rods on the
bottom, two each side. These rods hold the
housings in line with each other and square
with the frame. Two more torque rods on the
top maintain drive flange alignment.
The only lubrication needed in this Rockwell
suspension is at the spring saddles and trun-
nion. A grease fitting or oil plug is supplied.
Rockwell suspension systems are available in
various load Lirrying capac'lles and are
found on many on-highway and off-highway
tandem drive, trucks.
(6-238)
Courtesy of Rockwell International Automoire Operitti ms

467"
6:174 WHEEL MACHINES

Mack Lear Suspension REAR AXLE HOUSING

SPINDLE MA) REAR . 'LE
Mack leaf suspension is similar to Rockwell HOUSING

suspension except that the spring it un- -REAR SPRING

derslung which lowers the vehicle's center of BRACKET
gravity (Figure 6-239) The springs are moun-
ted on saddles which in turn are attached to a
trunnion. Spring ends are secured to the axle
SPRING CLANPING
housings through rubber shock insulators PLATE
(Figure 6-240) slung below the axles. These
insulators serve to hold the housings in line
and eliminate the need for lower torque arms. SPRING END
BEARING BUTTON
Oscillation of the spring and saddle assembly
permits independent wheel and housing
movement. Axle housings are braced against
9 BUTTON ANTIRATTLE
rotation from driving and braKing by upper SPRING

torque arms, seen in the typical Mack

REAR
camelback spring assembly in Figure 6-241. SPRING /4A111 LEAF
Mack leaf suspension is lubricated at the COMPLETE TEND
point where the spring saddle oscillates on
the trunnion (Figure 6-242). SPRING SHOCK
INSULATOR -
REAR LOWER
_._,....E111r

---morrIkka., ....:.Liriiiii11
....* ,
REAR SPRING
BRACKET CAP
AND INSULATOR
tv;41:0, A
RETAINER
188-1
(6-240) SPRING ENO CONFIGURATION
Courtesy of Mack Truck Ltd

(6-239)
couriesy of Mack TIUCR Ltd

TORQUE ARMS

REAR
FRONT

SPRiNO
TRUNNION
SPRING...I..
CLIP
NUTS
LONA RIMER
SHOCK INSULATOR UPPER RUBBER
SHOCR INSULATOR CAP SHOO( INSULATOR
Ni.$4
(6-241) TYPICAL CAMELBACK SPRING ASSEMBLY
Courtesy or Mack Truck Ltd

468
 WHEEL MACHINES 6:175

LOCATION OF LUKE
FITTING OR OIL FILL HOLE
CURRENT LOBE
ON NON-CURRENT BOGIE.
FITTING LOCATION
II IS AT REAR OF TAPPED HOLE WAS RETAINED
AND CLOSED WITH A PIPE
L H TRUNNION AND
AT FRONT OF R PLUG ON SOME CAPS AFTER
TRUNNION
LUBE POINT WAS MOVED TO
TRUNNION.
140.60

(6-242) LUBE FITTING LOCATION Courtesy of Mack Truck Lid

SPRING TYPE BOGIE

Mack leaf suspension is available in RUBBER SUSPENSION

capacities of 34.000 lbs. to 80,000 lbs. and is
suitable for both on-highway and off-highway Rubber Spring Suspension
service.
An per popular type of tandem suspension
(also available for single axle suspension) is
rubber spring suspension. it is very rugged
and it comes in a variety of load ratings
making it adaptable to both on-highway and
off-highway vehicles. The rubber suspension
in Figure 6-243 is made by Hendrickson and is
almost identical to the Hendrickson leaf
spring suspension except that rubber blocks
replace the springs.

Zip

-:--174

(6-241) Courtesy of Hendrickson Manufacturing I

469
 -.- 101/1.
6:176 WHEEL MACHINES

The rubber cushions are mounted on saddles.

The frame brackets are secured to the rubber
suspension cushions by rubber-bushed drive
pins (Figure 6-244). Without load, the unit
rides on the outer edge of the cushions. As
the load increases, the crossbars of the
cushions are progressively brought into con-
tact to absorb the additional load. The four
drive pins maintain suspension alignment, the
rubber busnings permitting the drive pins to
move up and down in direct relation to
movement of the load cushions.
The equalizing beams carry the load and act
as the lower torque rods. As shown in Figure
6-244. upper torque rods are required, similar
to previously described suspension assem-
blies.
(6-2 45) Courtesy N Linn Rig and Equipment Co.

NUT TORQUE FRAME 0.50 FT.-LBS.

200.250 FT. 485, 90.110 F1.4115. TORQUE ROD
..---k--
NUT TORQUE
90.110 FT.-LBS.
i$
Ill
I ,
III tv
MT '
if -I :MO: r/4 a ,
I s 'no xs 4
+.dyinrw.w rte
JT/irT /
90-110 FTABS. wiz , tOAD
CUSHION
VERTICAt DRIVE
VERTICAL $'I
BUSHING CAP i
uI DRIVE PIN I)
If
lei 00-125 FT.-LBS. 175-225 FT.-LBS. i°
f
I

01
;
SADDLE VERTICAL DRIVE BUSHING It

190 -210 "ABS* SADDLE CAP 225.275 FT.LBS.

FRONT CROSS TUBE EQUAtIZING BEAM T.6919

(6-244) TANDEM REAR AXLE SUSPENSION Courtesy of General Motors Corporation

(HENDRICKSON RS-380)
Rubber Column Suspension This truck has a rubber cushioned suspension
unit at each wheel. The units are columnar
Another type of rubber suspension is used on shaped at the front. and rectangular at the
large off-highway mine haulage trucks such back. The rear axle box is suspended by two
as seen in Figure 6-245. units, one at each rear corner, while the front
suspension is two independent units. Each
suspension unit consists of a column of rub-
ber pads inside two concentric suspension
housing;, Compression of the rubber pads
provides the cushioning effect.

470
 WHEEL MACHINES 6:177

A front suspension unit is shown in Figure 6- Figure 6-247 shows a rear suspension unit.
246. Note that this cylinder, as well as sup- The lower, inner housing slides within the up-
porting the vehicle, also has a steering arm per, outer housing and the rubber pads
that attaches to the front wheel. provide the cushioning between the two. The
upper housing and the rubber pads provide
the cushioning between the two. The upper
housing is attached to the frame through a
spherical bushing, while the lower housing is
attached to the axle box by a clevis and pin
arrangement. Mountings for these rubber
suspension units are discussed along with
hydro-air suspension mountings.

RUBBER CUSHIONED
STEERING ARM
SUSPENSION UNIT
(6.246)
Courtesy 0 Unit Rig Equipment Co

44
-e

LOWER INNER UPPER

OUTER
HOUSING
HOUSING

r--

RUBBER PADS r.r.

";44,411..14., a

(6-247) REAR SUSPENSION

Courtesy of Unit Rig Equipment Co

471
6:178 WHEEL MACHINES

HYDRO -AIR SUSPENSION

Hydro-air suspension is generally found on
large off-highway haulage trucks. Caterpillar.
Wabco. Terex. are but a few of the manufac-
turers who use hydro-air suspension (Figure
6-248). NYORAIR Suspension. When bottom .101
section slides up, nitrogen gas is 4
compressed, torcing on into
annular chamber tha combined 7
cushioning absorbing the shock.
:s. Oz t;;
Ben check valves prevent
oil from flowing back
too qukkly. ,
ir 04'
4,:t; .

1. Bottom section
2. Suspension housing
3. Nitrogen Gas
4. Oil (Main Chamber)
5. Annular (damping)
chamber
e. 9NI check valve

REAR HYORAIR

(6-248)
FRONT HYORAIR
Couriesy of Wabco Construction and
Mining Equipment

472
 WHEEL MACHINES 6:179

Figure 6.249 shows the suspension cy'inders ..;...,..._ --..

.1
r
,---0..:
r---r
as viewed from the front and the rear of the az
vehicle The two front cylinders act not only isk- _,
as a spring and shock absorber but also as a ....- ....
r- t, gr, 1-,
cn 1-1
king pin for steering. The suspension cylinder .......
....,
piston has an up and down motion for spring ....... 4111M11
and shock absorber action. and a rotary
motion for steering action.
c

mii.AA""b
(6-250)
Courtesy of Caterpillar Tractor Co.
The two rear suspension cylinders are at-
tached at the bottom to the axle and at the top
to the ends of the frame (Figure 6-250). The
axle housing is supported at the front by a Y-
shaped member called an anchor structure.
The anchor (Figures 6.261 and 6-252) is at-
(6-249) tached to the front of the housing in two
Courtesy of Caterpillar Tractor Co places and to the frame at one point. This
Wabco frame attachment has a ball bushing
arrangement which allows the housing to
oscillate from side to side, as well as ver-
tically. yet still hold the housing in line. Cater-
pillar uses a similar anchor structure on their
SUSPENSION rear hydro-air suspension. One difference.
CYLINDER
though. is that Cat uses an anchor ball rather
than a ball bushing at the frame attachment.
J

LJ
- r-r
r
**,

ANCHOR STRUCTURE
__.1

(6 -251)
Courtesy of Wabco Construction a: :
0 (4) 6

Moslem; Equipment (6-252) ANCHOR PIN ASSEMBLY

1. 5. Anchor Structure
Ball Bushing Cage
2. Spring Pin 6. Retainer Plate
3. Anchor Pin 7. Capscrew
4. Ball Bushing 8. Spacer
Courtesy of Wabco Construction and
Mining Equipmeni

673
6:180 WHEEL MACHINES

from the core of the piston through orifices (4)

to cavities (6) and (7). The transfer of oil into
ANCHOR BALL and out of the cavities gives a damping action
that prevents the piston from bottoming in the
cylinder with a shock when it comes back
Y-SHAPED down.
ANCHOR STRUCTURE

MI NITROGEN
NI OIL
XI

(6-253) (6-255)
Courtesy of Cater') mar 'rid GiOl Co FRONT SUSPENSION CYLINDER OPERATION
For additional rear axle stability. a sway bar 1Cylinder. 2Nitrogen chamber 3Piston
(Figure 6-254) is attached to the top of the 4Onfices (two). 5Ball check. 6Cavity
axle housing and is anchored to the frame 7Cavity 8 Oil chamber.
Courtesy o! Caterpinar Tractor Co
rail. The sway bar absorbs lateral thrusts. Rear Suspension
fi
The cylinder and piston in rear suspension
Air (Figure 6-256) work opposite to the cylinder
,v and piston in front suspension. The piston is
attached to the frame and the cylinder is at-
tached to the rear axle. When the rear wheels
hit a bump. the axle raises and the cylinder
moves up over the piston. In rear suspension.
the nitrogen chamber (2) is in the core of the
piston and the cylinder is filled with oil. As the
SWAY BAR I cylir der moves up. it is cushioned by the
pressurized nitrogen pushing against the oil.
(6-254) VIEW FROM REAR OF MACHINE As in front susoension. a damping action is
Courtesy of Caterpillar Tractor Co created by oil transfer into and out of cavities
Hydra -Air Cylinder Operation (4) and (7).

Front Suspension
The front suspension cylinders consist of a
cylinder and a piston or rod. The cylinder is
attached to the truck frame and the piston or
rod to the front wheel spindles. When the
wheel hits a bump. the piston moves up into
the cylinder A chamber (2, in Figure 6-255)
between the head of the piston and the top of
the cylinder is charged with pressurized
nitrogen gas and cushions the piston as it
comes up into the cylinder. The piston (3) has
a hollow core :8) that is filled with oil.
As the piston is pushed into the nitrogen, (6-256)
pressure on the oil transfers some of the oil REAR SUSPENSION CYLINDER OPERATION
1Rod. 2Nitrogen chamber. 3Housing
4Cavity, 5-011 chamber. 6Ball check
7Cavity. 8Orifice.
Courtesy ol Catena' la; Tractor Co
474
 WHEEL MACHINES 6:181

4..C.

AIR k mkiii.1 fa.

LEVELING
VALVES
lek
AIR
SPRING I APIWA,
,

VERTICAL DRIVE PIN

ALUMINUM SPRING SADDLES

(AIR RESERVOIRS) 910111111111'°c..A

(6-257) Courtesy of Hendrickson Manufacturing Ltd

AfR SUSPENSION International Harvester Air Suspension

Another type of suspension is air suspension. Air suspension used on a single axle In
It is mainly used for transport vehicles that ternational truck is illustrated in Figure 6-258.
require a soft ride such as furniture vans and The parts are described below:
buses. There are a number of air suspension
systems manufactured. Three common ones
are discussed here: Hendrickson. In- LEVELING
ternational. and G.M.C. CONTROL VALVE

Hendrickson
-4--FRAME HANGER
The Hendrickson air spring in Figure 6-257 BRACKET
uses the same basic design as the Hen-
drickson leaf and rubbor suspension RIGID TRAILING
previously discussed. Air suspension is ac- ARM
complished through the use of air springs
mounted on alum:num spring saddles which AIR SPRING INTERMEDIATE
also serve as air reservoirs. Vertical drive pins SADDLE SPACER
LOCATING PAD
mounte ' in rubber bushings and relieve
AXLE ADAPTER
the air spring of any function except
cushioning the load. Leveling valves are ex- (6-258)
Courtesy 01 International Harvester
ternally mounted. They automatically regulate
the amount of air pressure required for the Trailing Arms The front end of the trailing
load, as well as keep the vehicle frame at a arm is connected to the frame hanger bracket.
constant height. The rear of the arm has a support plate for the
air spring.

Frame Hangar Brackets The frame hanger

brackets form the pivot point for each trailing
aim. A rubber bushing and bolt are used to
connect the trailing arm to the hanger
bracket.

475
6:182 WHEEL MACHINES

Shock Absorbers The shock absorbers are r, TOP PLATE r 1 ATTACHES

mounted at the frame and axle saddles. They ircer 71W^Ifj r Arrui
L-t TO FRAME
incorporate a hydraulic lock which reduces kr.
suspension shock by letting the suspension w
down easy when the axle is in its downward AIR CELL-..
travel. CONFIGURATION
SHOWN AT 80 P.S.1. p
Trac Bar The trac bar. prevents lateral ,-RUBBER
/ BUMPER
sway of the vehicle suspension. There is one
CLAMPING
trac bar on chassis with single axles and two
!4 PLATE
on chassis with tandem axles.

Air Springs The rolling sleeve bag is moun- y

ted between the top plate and the piston
(Figure 6-259). As the air spring (sleeve bag) PISTON
PLATE
is compressed, the air cell rolls over the
piston. A rubber bumper is located internally er
to prevent metal-to-metal contact. The rubber _

bumper can either be located at the top or (6-259) AIR SPRING ASSEMBLY "14"40.
bottom of the air spring. The air bags work in
Courtesy of International Harvester
unison from front to rear (not side to side).
There is no transfer of air fro- bag to bag be- Leveling Valves The control (leveling)
cause this would cause axle roll. valve operates automatically. Valves control
the flow of compressed air into or out of the
air springs.

G.M.C. Air Suspension

The G.M.C. air suspension in Figure 0-260
consists mainly of air springs (bellows) a
height control valve. control arms. and shock
absorbers.

FRONT
'41-441a

t.1
a BELLOWS
SHOCK. 6 SHOCK
ABSORBER o ABSORBER

it
/9N, Yr; :1 ---irr_VY
0
PIVOT BOLTS
CONTROL CONTROL
BELLOWS ARM ARM
SUPPORT A.0769

BRACKET 17

(6-260) AIR SUSPENSION SYSTEM

Courtesy General Motors Corporation

473
 WHEEL MACHINES 6:183

Air Bellows An air bellows (Figure 6-261) is Height Control Valve The height control
mounted between each control arm and frame valve is mounted to the frame and attached to
support bracket The bellows serves as a the forward rear axle by a non-adjustable link.
flexible connection between the frame and The valve operates when the vehicle's load in-
rear axles Flexing of the air bellows results in creases or decreases, automatically in-
an alternate increase and decrease of air creasing or decreasing pressure in the
volume This action absorbs road shocks in a bellows. As the frame settles under an
manner similar to an inflated rubber tire. increased load. the height control arm linked
to the forward rear axle is moved upward. The
BEAD PLATE WITH arm actuates the valve, and a sufficient
AIR ENTRANCE
volume of air is admitted to all four bellows to
maintain the frame at normal ride height.
During unloading, the valve exhausts air from
the bellows.
Axle Control Arms Control arms hold the
rear axle in position. transmit driving and
braking forces to the frame, and provide roll
stability. A good view of control arms is given
in Figure 6-262.

BEAD PLATE WITH

BUMPER STUD
(6-261)

fRONIC REAR BELLOWS

FRONT BELLOWS
loi
1 '
0'
1

FRAME BRACKET PIVOT BOLTS

UBOLT ANCHOR PLATE

/
BELLOWS SUPPORT BRACKET

Courtesy of Generat Motors Corporairon

(6-262)

477
6:184 WHEEL MACHINES

QUESTIONS WHEEL MACHINE 12. Mounting the equalizer beams on Hen-

SUSPENSION drickson suspension below the axle
housings:
1. Wha! are the two main types of suspen
sion for wheel machines? Briefly state (a) keeps the beams out of the way.
the advantage of each. and give an (b) lowers the center of gravity for bet-
example of a machine where each is ter stability.
used.
(c) protects the axle housings and
2. What is the function of a bolster in rigid springs,
suspension?
13. fn a four- spring Reyco suspension
3. How does a skidder frame differ from a system what method is used to maintain
loader frame? suspension alignment and stability?
4. How does grader suspension give 14. Briefly explain how the mounting of
maximum wheel contact with the Rockwell spring suspension differs from
ground? Hendrickson equalizer beam suspension
mounting.
5. Truck frames are constructed of
basically two parts: _____ and 15. Mack camelback spring suspension is
mounted similar to:
6. Frames may be constructed of three (a) Hendrickson suspension
shapes of material: Reyco suspension
(b)
1-beam. round tubing and flat. (c) Rockwell suspension
channel. box and I-beam. 16. What method is used to maintain align-
channel. flat and round. ment in Hendrickson rubber block
1-beam. channel and flat suspension?

7. List the four common types of spring 17. What are the two-purposes of the front
suspension. rubber suspension units used on large
mining trucks?
8. The stiffness of a leaf spring is referred
to as its: 18. Hydro-air suspension cylinders are
precharged with:
(a) hardness
(a) nitrogen
(b) resilience
(b) oxygen
(c) rate
(c) hydrogen
(d) size
(d) carbon-dioxide
9. Briefly explain the difference between a
constant rate spring and a progressive 19. What is the advantage of air suspension?
rate spring. Where is it likely to be used?
10. What is the advantage of a progressive 20. What is the function of leveling or height
rate over a constant rate spring? control valves on air suspension?
11. A tandem axle suspension permits the 21. The front of the axle housing on a
truck to carry heavier loads because the machine using hydro-air suspension
load is distributed over: cylinders is supported by an
(a) the cab of the truck.
(b) one axle when unloaded and two
when loaded.
(c) a greater number of springs.
(d) a greater number of axles. springs
and tires

478
 WHEEL MACHINES 6:185

MAINTENANCE AND SERVICE REPAIR ON Scheduled maintenance on rigid suspension

RIGID AND SPRING SUSPENSION would include the following:
PREVENTIVE MAINTENANCE LOADER, Caution: Never work on a machine until ser-
GRADER AND SKIDDER RIGID SUSPENSION vicing safety precautions have
been taken.
Although little maintenance is required on
wheel loader, grader, and skidder rigid I. Thoroughly inspect the main frame,
suspensions there are a few points of the looking for weld cracks. broken melds,
suspension that should be checked during the damaged brackets. cross membus and
daily walk around inspection of the vehicle. reinforcing gussets. Check the bolster
Prior to doing any checking take the following bushings and pins for wear or damage.
precautions: Special attention should be given to hinge
pin assemblies: be sure they are properly
Caution: To prevent personal injury, always centered and seals and bushings are in
lower all equipment with slight good condition. Any frame damage should
down pressure, stop engine, set be corrected or repaired immediately.
parking brake and block or restrain Note that most frames are made of a low-
machine before servicing it. unless carbon. heat-treated steel that has added
otherwise specified. Install the strength and hardness. This steel requires
safety bar on articulated machines. special welding procedures that should be
undertaken only by a qualified welder.
Daily, Routine Checks on Rigid Suspension
2. ro keep rust and corrosion to a minimum,
I Check the frame members. welded joints periodic painting of abrasions and bare
and brackets for cracks. metal is recommended.
2 Remove any debris build-up at the pivot 3. Check for loose axle housing mounting
point of articulated machines or at bolts. Retorque any loose bolts to
steering axles. specifications.
3. Visually check for loose drive axle 4. Lubricate pivot points: bolster pins. upper
housing mounting bolts. and lower articulation pins, front axle
pins. Check the service manual for grease
4. Visually check for loose wheel nuts. A fitting locations.
streak of rust underneath a nut is an 'in-
dication that it is loose. 5. Some articulated frame pivot points have
adjusting procedures. See Service
5. Check tire condition and pressure. Manuals.
Scheduled Maintenance on Rigid Suspension 6. Check tire condition and pressure.
Scheduled maintenance for rigid suspensions 7. Check for loose wheel nuts by retorquing
is a continuation of the daily checks, only a them to specifications.
more thorough Inspection of the overall frame
and suspension component is undertaken.
This inspection would generally be done at
500 to 1.000 hour intervals or every three to six
months. Refer to service manuals,
Before beginning the inspection, the frame.
drive housings and other related suspension
parts should be thoroughly washed with a
high pressure washer or steam cleaner. In
fact, keeping the machine clean on a regular
basis whenever possible is a good main-
tenance practice because it enables you to
see minor problems in their early stages.

479
 ..a. ..,.........1111.041.10

6:186

SERVICE REAPIR ON RIGID SUSPENSION

(GRADERS, LOADERS, AND SKIDDERS)
ii
WHEEL MACHINES
,

Removal of the suspension components from

a machine with rigid suspension essentially
involves removing the drive axle housings for
wheel loaders and skidders, and the tandem
housings for graders. A steering axle may also
have to be removed from some smaller t
;
loaders. Removing these components is
similar to removing crawler undercarriage (.1
components in that they are large, heavy parts
that require suitable jacking and lifting equip-
ment and solid blocks or stands to support the
machine. Safety must be foremost in mind
when doing the job.

REMOVING AND INSTALLING LOADER

OR SKIDDER SUSPENSION
1. To remove the axle housing;;, it may be
easier to first remove the working at-
tachment, i.e., ;he bucket or blade. Y

2. The general sequence of procedure to (6-263)

Courtesy of Massey Ferguson Inc.
remove the axles is as follows:
(a) Clean the suspension components
and prepare the machine for main-
tenance.
(b) Safely jack the machine until the
wheels clear the ground, and then
block it.
(c) It is easier for the axles to clear the
frame if the wheels are taken off. To
remove wheels use a wheel dolly
(Figure 6-263) or suitable lifting If q
equipment.
(d) Disconnect drive shafts and brake
lines (if applicable). Cap the lines
with correctly sized plastiL Ca: s, or,
if these aren't available, use tape or (6-264)
rubber stoppers. Never use rags be- AXLE MOUNTING AND JACK POSITION
cause they may introduce con- Courtesy 01 International Hari0510,
taminants into the system. Tag the
lines.
(e) Place a wheel jack under the axle
housing (Figure 6.264).
(f) Remove the bolts that attach the
housing to the frame. lower the
housing clear of the machine, and
wheel it out on the jack.
 WHEEL MACHINES 6:187

Figure 6.265 shows the axles removed

from a loader. In this example the bolster
and rear axle are taken off together.
However. the axle can also be removed
without taking the bolster off. TORQUING ALL BOLTS
TO SPECIFICATIONS

CE.95970

Courtesy of International Harvester

3. Often. articulated wheel loaders have a

counter weight on the rear main frame. 141111Ert

Should it be necessary to separate the two

al
frames of such a machine. be sure the
rear section is adequately supported. In
Figure 6.266 a fork lift is used to hold up
the weighted end. The front frame should 14, ::11;-
- s.
also be supported and the wheels jarr
blocked. ,4

Also when separating articulated

machines. hydraulic lines will have to be
disconnected. Make sure that pressure in
the system is neutralized before discon-
necting the lines. Cap and tag the lines. 88817x1

(6.266)
Counesy of Caterpillar Tractor Co

481
6:188 WHEEL MACHINES

WHEELS TANDEM Service Repair Grader Suspension

HOUSING
The two pivot points of a grader carry the
brunt of the machine's weight and it logically
follows that these points will need service
repair. Drive axle spindles and bearings also
need repair.
There are various designs used by manufac-
turers to attach the tandem housings to the
(6-267) final drives in such a way that they can
Courtesy of Caterpillar Tractor Co oscillate. The Caterpillar design shown in
Figure 6-269 is called an oscillation housing.
Removing Grader Tandem Housings When the tandem housing is lifted free of the
machine. the oscillation housing remains at-
On a grader the wheels and tandem housings tached to the final drive housing. The
make up the complete rear suspension oscillation housing is supported on the final
(Figure 6-267). The tandem housings oscillate drive housing by bearings and is held by the
parallel with the frame from a pivot point at retainer (1) and bolts (2) in Figure 6-269. When
the center of the housings. The housings are these bolts and retainers are removed. the
removed at this point (Figure 6-268). A more oscillation housing can be pulled free from
detailed view of tandem housing removal can the final drive housing.
be seen in the section on wheel final drives.

f I
IlEasi."W litr
iisti..,161 4,
)1 ---7_-_--(
I....._ F.....
2 .Aar .1
1
,,,....,
#
i, II
, ----a.
t A 1
. f
....oil!
A09964X I
....4.
(6-268) (6-269) 1 Retainer. 2 Soils.
Courtesy ol Caterpillar Tractor Co
C'unesy of Caterpillar Tractor Co.

Service Repair Loader and Skidder

Suspension
Repairs to loader and skidder rigid suspen-
sion are mainly concerned with damaged
mounting brackets and pads. worn bolt holes,
cracks in the frame. and cracked welds on
gussets and bracket cross members. On ar-
ticulated machines the center pin and
bushing or bearing will wear and require ser-
vicing repair or replacement. The bolster must
also be checked for cracks, and the bolster
pivot pins and bushings will also wear and
require servicing (replacing).

482
 WHEEL MACHINES 6:189

The oscillation bearing, thrust rings and 0-

ring seals are replaced on this assembly. Pre-
lubricate the new bearings, thrust rings and
0-rings with a little oil. Practise absolute
cleanliness on reassembly. When installing
the oscillating housing on the final drive
housing, be careful not to damage the 0-ring
seals. Figure 6-270 shows a cross-section of
the oscillation housing attached to the final
drive housing.

MAIN SUPPORT BEARING

FINAL DRIVE
DRIVE
HOUSING
SPROCKETS

OSCILLATION
HOUSING

THRUST BEARINGS TANDEM HOUSING

OSCILLATION
BOLTS TO THIS FACE
HOUSING 0-RING
SEAL
(6-270) Courtesy of Caterpillar Tractor Company

483
.. .
6:190 WHEEL MACHINES

QUESTIONS RIGID SUSPENSION

MAINTENANCE AND REPAIR
1. Prior to doing any preventive maintenance
checking on an articulated machine. what
precaution must be observed?
2. Why is it a good practice to clean a
machine on a regular basis?
3. What are the pivot points that may need
lubrication on a rigid suspension system?
4. if it is necessary to separate the two frame
halves on an articulated loader. what are
the precautions that should be taken?
5. List the kinds of things that may need
repair on rigid frame suspension.
6. What parts are usually replaced on a
grader oscillation housing?

484
 WHEEL MACH! NES 6:191

SERVICE OF TRUCK FRAMES AND 3. Visually check the irP.me for loose bolts
REAR SUSPENSION and rivets and for cracks. Also check for
DAILY, ROUTINE MAINTENANCE ON loose components.
TRUCK REAR SUSPENSION
4. Visually check for loose torque arm
A thorough daisy, routine maintenance check bushings and sr:aching bolts. Check the
of a highway truck rear suspension would in- condition of torque arms, spring saddles.
clude: walking beam bushings.
Caution: Before doing a daily, routine
check, park the truck on level 5. Check the condition of the shock ab-
ground. turn the engine off and set sorbers. Look for any leakage.
the parking brake. 6. Check the springs for cracked or broken
1. Check the condition and pressure of the [eaves. and for worn shackle pins.
tires. (See Tire section. Daily. Walk-
Around Checks). Remember, inspecting 7. Check for loose U-bolts.
truck tires is the single most important
check for highway safely. Loose U-bolts are often the cause of leaf-
spring breakage. axle misalignment. hard
2. Visually check for loose wheel nuts. As steering. and abnormal tire wear. TIM. ten
mentioned earlier rusty marks around nuts Ubolts (Figure 6.272) after the first 500
Illicate looseness (Figure 6-271). miles (800 km) on a new vehicle as the
springs settle and cause U-boll tension to
slacken. Check the U-bolt tension of on-
highway vehicles ever/ 25.000 miles
(40,000 km). Check off-highway vehicles
weekly. The vehicle should be loader, to
its normal gross weight when tightening
the U-bolts. The use of a torque wrench is
highly recommended. if U-bolts or nuts
need replacing, do not risk an accident by
using common U-bolts or standard nuts.
Use only U-bolts and nuts of SAE Grade 8
specifications.
On off-highway trucks that have hydro-air
suspension, cheek the suspension cylin-
der piston extension (Figure 6-273). The
cheek should be made when the vehicle is
level, empty and has come to a gradual
stop. Allowable tolerances are given in
service manuals. Report if the piston ex-
tension is not within the acceptable range.
Also check the cylinders for leakage.
a
(6-271)
RUST STREAKS FROM STUD HOLES i
CAUSED BY LOOSE CAP NUTS
Courtesy of Oudd

(6-272)
Courtesy of Kenworth Truck Company

485
6:192 WHEEL MACHINES

Mar 1-
yi
4

T: J.
O. I

n
111-44111111
r

FRONT CYLINDERS (6-273) REAR CYLINDERS

Counesy of Caterpillar 'Motor Co,

SCHEDULED MAINTENANCE OF TRUCK

REAR SUSPENSION
In truck service manuals, scheduled main-
tenance will mainly consist of lubrication
schedules. However. service people. should
do more on suspensions than just perform
lubrication service. They should be observant.
always looking for minor problems before they
develop into major ones.
An example of the lubrication schedules for a
heavy duty. off-highway truck is given in
Figure 6-274. Note that the severity of off-
highway operating conditions often demands
more frequent lubrication than on-highway
operation. Whereas offhighway wheel
bearings are packed every 10.000 miles, on-
highway bearings are packed at ap-
proximately every 25.000 miles.
At the same time that the lubrication is done.
all the points mentioned in daily. routine main-
tenance should be checked. It is a good idea
to clean the suspension components before
undertaking the inspection.
 WHEEL MACHINES 6:193
roO..11441011O1

KENWORTH MAINTENANCE MANUAL

LUBRICATION CHART
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"RA 18149A 0ATE1 8.89 (6-274) PART A -tUIRICATION

Courtesy of Kenworth Truck Co

487
6:194 WHEEL MACHINES

SERVICE REPAIR OF TRUCK FRAMES There are several methods of identifying heat-
AND REAR SUSPENSION treated frame rails. The most common is a
stencil marking on the inside middle section
Frame Alignment of the rail or a stencil mark on one of the
cross members. The stencil notes that the rail
Frames can become misaligned, although is heat-treated and rail flanges must not be
usually misalignment will occur only as a drilled or welded. It is a caution against
result of an accident. When a frame is welding additional, brackets cross members,
misaligned the cross members are out of or full length reinforcement rails to the frame.
square with the rail& The cause cln be a bent Minor repairs to heat-treated frames. as
or twisted rail or one of the rails could be shown further on in this section. are ac-
pushed forward or backwards. A vehicle with ceptable.
an obviously misaligned frame would be sent
to a frame shop for repairs. or to have one or A second method of identifying heat frame
both of the rails replaced (on larger trucks). rails is to have small patches covering
"Brinell- test marks along the inside (web) of
Frame alignment can be checked by dropping the rail. These patches are found about every
a plumb bob from the frame to the floor at three or four feet. The patch can be removed
points K in Figure 6-275. If the diagonals are to expose the "Brinell" marking. A third
not the same or within allowable tolerances of method is to stamp "H" for heat-treated on the
one another. that section of the frame is upper face of the rai; flange about three in-
misaligned. The use of the plumb bob to trans- ches from the rail end.
fer frame points to the floor is necessary be-
cause all the parts and pieces attached to the REPAIR ON NON-HEAT-TREATED FRAMES
frame make it impossible to put a square
against the rail and cross member or to Cutting
measure the diagonals with a tape.
Whenever it is necessary to cut the frame. the
&de rail should be cut at an angle of 45
degrees. This method distributes the cut and
web over a greater area than a cut made at
right angles.
CROSS MEMBER
DIAGONALS
Reinforcing
Reinforcements may be made with flat. chan-
nel or angle stock. Reinforcement thickness
K should not exceed the original side rail
(6-275) thickness. Because of difficulties en-
Frame Repair countered when inserting channel rein-
forcements into the frame side rails. the use of
The following material about frames, and angle reinforcements is acceptable. When
frame repair, is used courtesy of International ever possible, the reinforcement should ex-
Harvester. tend from the front axle to slightly beyond the
rear spring front mountini bracket. If a rail is
Since frames must keep the major com- damaged beyond repair. cr if it is too costly to
ponents of a vehicle in their relative positions. repair. the complete rail may be removed and
they should be kept in good condition. Truck be replaced wilt, a new one. (New rails may
frames are manufactured with frame rails of also be installed on heat - treated and
either non-heat-treated steel, heat-treated aluminum alloy frames.)
steel or aluminum alloy. It is importaat to be
able to recognize the different frames be- Hot rivets are acceptable to attach rein-
cause they have different repair procedures, forcements, and they can be driven with hand
tools. Cold rivets should only be used when
No difficulties should be encountered in iden- you have tools of sufficient power to properly
tifying aluminum alloy frames because the set the rivets. The diameter of the rivets
side rails and cross members are made of should be 50 to 100 percent of the total
thicker material than are the components of a thickness of the plates to be riveted.
steel frame of comparative size. If there is any
doubt, use a file to check the material's hard-
ness or color.

488
 WHEEL MACHINES 6:195

Welding
Electric arc-welding is recommended for all
frame welding. The reinforcements should be
welded to the frame after the reinforcements
are riveted. All unused holes should be filled
with welding material. The v eldingrod should
have a substantial amount of the same
material that is used in the frame. WELD
REINFORCEMENT
Preparation Of Frame For Repair PLATE

Before welding the reinforcement to the

cracked section of the frame side rail. certain FRAME RAIL
preparations are necessary to insure strength 440517
(6-277)
and stability. To prevent further spreading of
the crack. a hole should be drilled at the star- Courtesy of international Harvester
ting point of the crack (Figure 6-276). Widen Frame Straightening
the crack its full length using two hacksaw
blades together Groove or bevel both sides of Use of heat is not recommended when
the crack so that the weld establishes a solid straightening non-heat-treated frames be-
contact between the reinforcement and the- cause heat weakens the structural charac-
frame side rail The grooving can be done teristics of frame members. All straightening
with a grinder or a cape chisel. should be done cold, Frame members (except
aluminum) which a;e bent or buckled suf-
ficiently to show cracks or weakness after
straightening, should be replaced or rein-
forced. Note that when replacing a rail, never
DRILL HOLE WIDEN CRACK intermix the frame material; the new rail
material must match the old.

REPAIR OF HEAT TREATED FRAME

.----' Heat treated frames require special welding
preparations and techniques. Consult the ser-
vice manual or welding manual for the correct
BEVEL EDGES
heat-treated metal welding practices. Welds
FRAME RAIL
on heat-treated material tend to reduce
A.40516 (6-276) physical properties in the area affected by
Courtesy of international Harvester weld heat. Because of this. It is recommended
that reinforcements be shaped so that all
When welding reinforcements it is important welds are parallel. rather than perpendicular.
that you do not weld into the corners of the to the frame rail edges (Figure 6-278). Welds
frame or along the edges of the frame side rail perpendicular to the flange edges will reduce
flanges. points "A" in Figure 6-277. Welding at the carrying capacity of the rail.
these points tends to weak'n the frame and REINFORCEMENT EXTENDS AT LEAST
encourages the development of new cracks. FOUR INCHES EACH SIDE OF CRACK
Note the shapes of the reinforcements and the
angles of the welds. Always avoid welds made
square with the side rail. either on webs or CRACK NOTCHED
flanges. When welds are made at an angle of OUT FILLED WITH
WELDS
at least 30 degrees from square. there is less PARALLEL WELD AND GROUND
possibility of setting up dangerous stress con- TO FRAME RAIL FLUSH
centrations in the rail. EDGES

3/4" MINIMUM
METHOD OF REINFORCING
(6.278) CRACK IN FRAME
Courtesy of iniernatsonat Harvester

. , 489
 6:196 WHEEL MACHINES

Wherever possible, it is recommended that heat is not recommended for straightening

plug welds (Figure 6-279) be substituted for these rails. Cracked or fractured aluminum
edge welds when attaching the reinforcement frame rails should always be replaced.
to the side rail. Plug welds otter the ad-
vantages of a reduced heat-affected zone, in- SERVICE REPAIR ON SPRING SUSPENSION
creased flexibility and reduced stress con-
centrations. When using this method. one half Removal
inch (minimum) diameter holes should be
drilled and beveled in the reinforcement at Below are general procedures for removing
two inch center to center distances. At no Hendrickson spring suspensions. Similar
time should these holes be drilled in the frame procedures are used to remove other spring
rail being repaired. The reinforcement should suspensions such as Reyco and Mack. See
then be placed over the repair point on the rail Service Manuals for exact procedures. The
and the holes filled with weld material. Again entire suspension is removed here. but if need
a minimum dimension of three-quarter inch be. the torque arms. springs. equalizer beams,
should be maintained between the weld and hangers may be taken out individually.
the edge of the side member flange I. Block the tires on both axles and discon-
nect the brake lines from the axles.
2. Disconnect the drive axles at the universal
PLUG
WELDS
joints either by unbolting the companion
flanges or by disconnecting the universal
joint yakes.
112" DIAMETER
PLUG WELDS 3. The suspension is taken out in two stages.
.,-.It' t
-...,4,--- In the first stage the equalizing beams are
unbolted from the springs (Figure 6-280)
PLUG WELD METHOD OF and the torque arms are disconnected at
REINFORCEMENT ASSEMBLY the axle brackets. Care should be taken
MT.4986 when disconnecting the torque rods, since
(6-279)
counesy of International Harvester the axle assemblies may be free to roll or
pivot at the equalizer beam ends. The
Full Length Reinforcement frame is then lifted with a hoist. and the
equalizer beams and axles are rolled out
When heat-treated frames are to be reinforced on the wheels.
over a greater portion of their length, frame
channel reinforcements should be installed
using bolts. Bolts of high strength material
conforming to SAE Grade 5 or better should
be used. The bolts ana nuts should be in-
spected periodically and kept tight since the
strength of the reinforcement depends
somewhat on the maximum clamping force
between the members.

Frame Straightening
When heat-treated frame rails have been bent
or twisted, they should not be heated for
straightening. Straightening should be done
with the frame rails cold. Heating is likely to
destroy the rail temper in localized areas and
cause rail failures. (6-280)
Courtesy of Hendrickson Manufacturing Lid
Repairs On Aluminum Alloy Frames
The cutting of aluminum alloy frame rails for
repair or reinforcement is not approved be-
cause aluminum rails cannot be welded
without losing their original strength. Also

490
 WHEEL MACHINES 6:197

4 The frame is then blocked. A floor jack is bushings. Pressures required to remove the
paced under the spring and saddle bushing and sleeve assemblies will generally
assembly (one at a time), the spring pin is be between 35 to 50 tons.
removed, and the spring is rolled out on
the jack (Figure 6-281). Note: Do not use a cutting torch to aid in the
removal of bushings from equalizer
beams. The beams are heat-treated
and the heat from the torch will
f weaken them. Repair of spring
suspension parts are discussed below.

Spring Hangers
Check the condition of spring hangers. Also
check the spring pin holes on the front
hangers and the cams on the rear hangers. If
the hangers are worn excessively. they should
be replaced. At major overhauls. spring
hanger pins and spring eye bushings (if the
springs are to be reused) should be replaced.
4 "."...
ei,......W. Springs
4 . ,
." ..... 4
e( --.;..0.1. . va..., .- Putting aside the fact that springs can be
i:-....:"""mw. ---,%:. -... ' ."....4....:Szist--4 -4.! 4_ broken by loose U-bolts, springs eventually
(6-281) wear out due to metal fatigue. Fatigue cracks
Courtesy of Hendrickson Manufacturong LW
start at a scratch, notch or rust spot and
progressively deepen and lengthen. Some of
Cleaning and Inspection the factors affecting fatigue (i.e.. spring life)
are: vehicle gross weight, type of load, road
Clean all dirt from the suspension parts and conditions. vehicle speed, and suspension
inspect them carefully for cracks or damage. maintenance practices.
Magnaflux or fluorescent equipment may be
used to inspect the parts. Inspect the rubber Before disassembling the spring. mark with a
bushings for damage or deterioration. chalk or grease pencil down one side of the
Petroleum products usually will not harm the spring so that you know the original position
Hendrickson equalizing beam center of the leaves on reassembly. To disassemble
bushings because they are not in an exposed the spring. place it in a vise (small springs) or
position. However, the outer edges of the an arbor press (large springs) next to the cen-
beam's end bushings are exposed and will ter holt.
deteriorate from continuous oil saturation. If The problem when inspecting springs is to
the suspension has been in service for a long determine if it is better to repair or to replace
period of time. it is advisable to replace all broken springs. Consideration should be
bushings. given to spring mileage, number of previous
Most repairs to spring suspension systems repairs and relative cost of repairs compared
consist of replacing worn or damaged parts. to the cost of new springs. If one spring is
The major item that will concern the ser- replaced. it is recommended that the other be
viceman on equalizer beam suspension is replaced as well. otherwise the deflection
removal and replacement of the rubber would differ on each side. The same can be
bushings. While bushings have long life. they said for shock absorbers. replace them in
eventually deteriorate arid need replacing. pairs. Below is a guideline to use when con-
Special service tools for replacing bushings sidering the question whether to repair or
on equalizing beams are made: they are the replace springs.
best tools for the job. but are not absolutely
necessary. If press equipment is available, When To Repair Broken Springs
standard steel tubing having diameters to 1. If the spring has been repaired not more
match the bushing sleeves (metal bands than once already.
surrounding the rubber bushings) can be used
as adapters for removing ard installing the

491
6:198 WHEEL MACHINES

2. If spring mileage is less than half of the REINFORCEMENT

spring's normal life (approximately
200.000 highway miles or 75,000 off-
highway miles). TORQUE ARM
3. If the cost of repairs is less than two-thirds
the cost of new springs.
If the converse of any of these three points is
true. replace the springs.

Torque Rods
Torque rod ends deteriorate after long service
SPACER SHIMS
life. Many torque rod models have replaceable
ends (Figure 6-282) that are press fit into the TORQUE ARM
rods. BRACKET

(6-283) VIEW IN DIRECTION OF ARROW Y

1 Courtesy 01 Ford Motor Company
1
U.5
AXLE OR BOGIE MISALIGNMENT
When a vehicle has done many miles of ser-
0 vice. chances are axle misalignment will exist
due to normal wear of the suspension parts. If.
during the scheduled maintenance checks,
accelerated or abnormal tire wear Is noted.
the rear suspension alignment should be
checked. Axle housing(s) should be square
with the frame and tandem axles parallel with
one another. Misalignment should be correc-
ted immediately because it can greatly add to
the operating costs of the vehicle through ac-
celerated tire wear. Vehicles that have had
their rear suspension rebuilt should also be
checked for correct axle alignment.
(6-282)
Courtesy 01 Hendrickson Manufacturing Ltd Some suspension systems are more likely to
become misaligned than others due to their
Upper torque rods are adjustable or have ad- number of moving parts. However, misalign-
justing shims either between the rod and its ment usually occurs only after many miles or
mounting bracket or between the mounting hours of service. Some systems, e.g.. Rock-
bracket and the frame cross member (Figure well. have a means of correcting misalign-
6-283). It is essential for drive line alignment ment. while others such as Hendrickson don't.
(i.e.. alignment of companion universal joint Alignment problems with Hendrickson
flanges or yokes) that torque rods be rein- suspension usually indicate a major suspen-
stalled in the exact position from which they sion overhaul is needed.
were removed. Adjustable rods should not
have their adjustments altered. and shim pack
thickness should be identical. The importance
of having torque rods properly installed and in
good condition cannot be over-emphasized.

492
 WHEEL MACHINES 6:199

Checking Alignment
A common method (courtesy of Rockwell In-
ternational) for checking bogie alignment is
given below. This method involves squaring
and clamping a straight edge to the frame and
then measuring from the straight edge to each
side of the axle (Finure 6-284). The
measurements should be the same (or within
allowable tolerances) if the axle is aligned
with the frame. Note that the straight edge
should extend at least one foot further than
the overall tire width. The straight edge
method is used here to check the alignment of
tandem axles, but it may also be used to
check single axle alignment, front or rear.

..M. ..

I.... M.I .,
'..
.wOmb 411
I

_ ..-0
--
1111 .,1I
I

I iI

.11 AelI
011
In

1 1 i_.... _. O.M1, O.MI, ...

0 B

....T.
Uk=m0
A

STRAIGHT EDGE

TOOL
4,

1
Courtesy ol Rockwell international
(6-284) Automotive Operations

493
6:200 WHEEL MACHINES

1. Measure distances (A) from the straight Universal Joint Companion Flanges
edge to the connecting tube centers.
Tolerance: 1/16". This measurement tells A very important adjustment related to rear
you if the suspension assembly is parallel suspensor. is the parallel alignment of the
with the frame. universal joint companion flanges (Figure 6-
285). Removal and installation of the rear
2. Measure distances (B) from the straight suspension assembly or the upper torque
edge to the back rear axle center. arms can throw out the universal flange align-
Tolerance. 1/8". This measurement tells ment if not done correctly. A one degree
you if the back rear axle is perpendicular tolerance is all that is allowed.
with the frame.
When removing shimmed torque rods.
3. Measure distances (C) from the straight carefully note the number or size of the shims
edge to the front rear axle center. and reinstail the rods with exactly the same
Tolerance: 1/8". This measurement tells size shim pack. When removing an adjustable
you if the front rear axle is perpendicular torque rod, be careful not to disturb the
or aligned with the frame. threaded adjustment; the adjustment must be
in exactly the same position as when the rod
4. Measure axle center distances (D) to see was removed.
if the axles are parallel. Tolerance: 1/4".
Note the tool that is used to measure the
Apart from improperly installed torque arms.
axle centers. universal misalignment on tandem axles can
If misalignment is found, first check to see also be caused by worn torque arms. To
that it is not caused by: correct the misalignment, torque rods have to
be adjusted to tilt the axle up or down.
bent axle housings Depending on the type of torque rod, ad-
frame damage justing the rod involves: (1) adding or taking
away shims. (2) adjusting the rod itself or (3)
wheel bearings obtaining a new rod of the correct length. An
If it is not, then refer to the service manual for apprentice should not attempt to correct
the procedures to correct the misalignment. universal misalignment unless under the
Some faulty alignments may be corrected by guidance of a journeyperson.
simply making adjustments, while others will Note that misalignment of.the universal com-
require repair or replacement to correct such panion flanges or yokes on single axle trucks
things as loose bolts, elongated holes in the is not usually a problem because spring sad-
frame support and connecting tube brackets. dles are solidly fixed to the housing and the
and worn torque rod ends. Servit,:: manuals fronts of the rear springs are attached to the
often give a list of likely causes of misalign- frame by shackle pins.
ment. Check through this list carefully, be-
cause often corrective action can be made on
the suspension without having to do a com-
plete rebuild.
FLANGES MUST BE PARALLEL
VERTICALLY AND HORIZONTALLY

(6-285)

494
 WHEEL MACHINES 61201

SERVICE REPAIR OF HYDRO-AIR Bleeding Procedures

SUSPENSION CYLINDERS
1. Before bleeding the cylinders support the
Special safety precautions must be practised vehicle's weight with a jack or with
when working with gas charged cylinders. blocks.
Warning: Do not attempt to check the oil in 2. Install nitrogen charging chucks on the
a suspension cylinder until all the nitrogen valves of both front or rear cylin-
nitrogen pressure has been ders and open the chucks to unseat the
released. Do not, under any cir- nitrogen valve.
cumstances. remove valves or
plugs from the cylinder unless the 3. Using a jack lower the vehicle's weight
rod is fully retracted and all the onto the cylinders until the rods are corn
nitrogen pressure released. Do not pletely retracted and all the nitrogen
stand under the vehicle when exhausted.
testing or adjusting the suspen-
sion cylinder because the rod can Checking Cylinder Oil Level
move suddenly causing the Once the nitrogen has been bled from the
overhead clearance to quickly cylinders, the oil can be checked. The
change. checking is done by pumping oil into the
cylinder through the nitrogen charging valve
Note the following points about hydro-air using equipment such as shown in Figure 6-
suspension: 286. When oil flows from a vent. the cylinder
has the right amount of oil. (See the service
1. There are four cylinders. two at the front manual for specific procedures.) Note that the
and two at the rear. Each cylinder oil must be checked in both the front or both
operates independently. the rear cylinders because the cylinders must
2. Binding can occur in diagonally opposed be simultaneously recharged with nitrogen.
cylinders if one of the cylinders is low.
3. Procedures for removing the front and the .44 C
rear cylinders is similar.
4. Repair of hydro-air cylinders may or may
not be done in a shop. If a shop is fre-
quently WC,7 ng on large off-highway
vehicles using hydro-air suspension. they
will probably rebuild suspension cylin-
ders.

5. The information here does not deal with

rebuilding the cylinders. but rather with (1)
bleeding the nitrogen charge (2)
checking/filling the oil (3) charging with
nitrogen and (4) removing and installing
the cylinders.

6. Removing and installing hydro-air cylin

ders is similar to the procedures to
A331s4X1
remove and install rubber cushion suspen-
sion cylinders except that no gas charge
is involved. (6-286) OIL CHARGING EQUIPMENT
Courtesy of Caterpillar Tractor CO.
Bleeding The Nitrogen Charge
To reduce the nitrogen pressure in the cylin-
ders the vehicle must be empty and on ground
level. A charging chuck is used to release the
nitrogen. Both front cylinders should be bled
at the same time. as should both the rear.

495
$1202 WHEEL MACHINES

Charging The Cylinders With Nitrogen Charging Procedures (Refer to Figure 6.287)
Warning: Dry nitrogen is the only gas ap- Warning: For personal safety it is very im-
proved (or use in suspension cylin- portant that valves be opened or
ders. Accidental charging a cylin- closed in the correct order.
der with oxygen will cause an ex-
plosion. This danger can be 1. Close the charging chucks (1).
eliminated by only using nitrogen 2. Close shut-off valve (2).
cylinders that have the correct
connections. Never use an adapter 3. Connect the nitrogen charging equip-
to connect a nitrogen charging ap- ment.
paratus to a valve outlet that has 4. Open the charging chucks (1).
been used interchangeably on
nitrogen, oxygen, or other gas 5. Open the nitrogen tank valve (3) and ad-
cylinders. Do not rely on color just the valve until the gauge reads ap-
coding or other methods of iden- proximately 500 P.S.I. (35.15 kg/cm2).
tification to distinguish between
nitrogen and oxygen cylinders. Be 6. Open the individual cut-off valves (5) and
absolutely certain the tank con- open the shut-off valve (2). Charge the
tains dry nitrogen. cylinders until the proper extension is
reached.

1 2 3
7. To stop the charge close:
(a) the shut-off valve (2)
(b) the nitrogen tank valve (3)
(c) the charging chucks (1)

5
4 8. Note that step 7 must be followed each
: time the rod extension is checked while
charging.
9. After performing step 7. the equipment
can be disconnected.
10. Recheck the rod extensions after the
vehicle has operated a few cycles. In-
crease the nitrogen pressure. if
necessary.

REMOVAL AND INSTALLATION

Front Suspension
lAt3S412x1 e-

The basic procedures for removing front

TYPICAL NITROGEN CHARGING ARRANGEMENT suspension cylinders are:
1Charging chucks (two). 2Shutoff valve.
3Nitrogen lank valve. 4Pressure gauge. 1. Bleed the cylinder, as previously
5Individual cul-off valves. described. The weight of the vehicle is
(6-287) held by blocks.
Courtesy of Calorpillat Tractor CO 2. Disconnect the brake lines (Figure 6-288)
and steering arm (if applicable).
Charging procedures for both front and rear
cylinders are the same. Setting the pressure 3. Disconnect the cylinder piston or rod from
at about 500 P.S.I. (35.15/ kg/cm2). the cylin- the spindle. This step may involve special
ders are charged with nitrogen until the piston spindle-removing tools.
rods are extended to the exact length
specified in the manual.

496
 WHEEL MACHINES 6:203

4. Roll or lift out the wheel assembly.

Caution: On vehicles with large tires the
wheel assembly is very heavy
r 5
1911111.6111111P'w

and will require proper lifting

equipment.
5 Disconnect the cylinder from the frame.
4
Caution: Suspension cylinders can
weigh half a ton. Proper lifting
equipment is needed to remove
them. a
r

:f, t. 2

4
LOWERING SUSPENSION CYLINDER
1Rope sling. 2Mounting flange.
3Suspension cylinder. 4Lifting eye.
5 Chain hoist.
PREPARING TO REMOVE WHEEL AND SPINDLE (6-289)
1 -Wheel brake hydraulic line. 2 Bolts (four). Courtesy of Wabco Construction and
Mining Equipment
3Spindle. 4Steering arm.
(6-288)
Conitosy of Caterpillar 'tractor

6. The cylinder is installed in the reverse or-

der.
Rear Cylinder Removal
Removing rear suspension cylinders, unlike
front cylinders. does not require removing the
wheels. The cylinder is bled of nitrogen and
the vehicle is blocked. The cylinder is then
removed from its two mounts and lifted out by
a hoist. Note that on some off-highway
haulage trucks. the dump body has to be
removed before you can get the cylinder out
because the hoist will not clear the rear por-
tion of the body. Figure 6-280 shows a rear
suspension cylinder being lifted out of a large
truck (the dump body is removed). Refer to the
service manual for specific cylinder removal
procedures.

497
1
6:204 WHEEL MACHINES

QUESTIONS SPRING SUSPENSION 11. What is the recommended practice to

MAINTENANCE AND REPAIR stop further spreading of a crack on a
non-heat-treated frame?
1. The single most important suspension
safety check for on-highway vehicles is 12. Why are plug welds recommended over
to: edge welds for reinforcements on heat-
treated frames?
(a) make sure the windshield is clean.
(b) check for broken springs. 13. True or False. Bent, cracked or damaged
aluminum frame rails should not be
(c) make sure all the lights work. straightened or repaired: they should be
(d) check tire condition and pressures. replaced.
2. What is an obvious sign of loose wheel 14. When replacing bushings in the ends of
nuts? equalizer beams. why is it not recom-
mended to remove them with a torch?
3. To check the piston extension on
vehicles equipped with hydro-air suspen- 15. What are the two main causes of leaf
sion. the vehicle should be: spring failure?
(a) at operating temperature, loaded, 16. What four measurements are taken to
and on level surface. check bogie alignment?
(b) at operating temperature. loaded, 17. True or False. If one spring is replaced it
and on any surface. is recommended that the other one be
(c) cold. unloaded. and on a level sur- replaced as well.
face.
18. What rule must be followed when
(d) at operating temperature. unloaded. removing and installing upper torque
and on level surface. rods? Why?
4. Is there a difference between the recom- 19. Why is universal misalignment not
mended frequency of service on an off- usually a problem on single axle trucks?
highway vehicle and an on-highway
vehicle? Briefly support your answer. 20. What procedure must be followed before
checking the oil level in a hydro-air
5. List the problems that loose U-bolts can suspension cylinder?
cause.
21. List the steps to bleed the gas charge on
6. When tightening U-bolts. it is recom- a pair of hydro-air suspension cylinders.
mended that the vehicle be:
22. True or False. Since the oil level in the
(a) loaded. suspension cylinder cannot be checked
(b) unloaded. visually. oil is pumped into the cylinder
until it flows freely from a vent hole.
(c) either loaded or unloaded: it doesn't
matter. 23. When recharging hydro-air suspension
(d) on a level surface. cylinders, the correct procedure is to:

7. Briefly explain why it is recommended to (a) charge only one at a time.

cut a frame side rail at a 45 degree (b) charge them as a pair, both front or
angle. both rear.
8. Why should a non-heat-treated frame not (c) charge one front and one rear on
be welded in the corners and on the the same side.
edges? (d) either of the above is acceptable.

9. True or False. Heating a frame to

straighten it is an acceptable practice if
done carefully.
10. What are three ways that heat-treated
frames are identified?

498
 WHEEL MACHINES 6:205

ANSWERS WHEEL MACHINE 14. Hendrickson equalizer beam suspension

SUSPENSION is mounted below the axles. Rockwell
suspensioa, on the other hand, has the
1. Rigid suspension: good stability, e.g., outer ends of the springs resting on top
wheel loader. skidder, grader. of the axles. The centers of the springs
;',pring suspension: smooth ride. e.g., are attached to spring saddles which
highway trucks. mount and oscillate on a dead axle
called a trunnion shaft.
2. A bolster allows the axle housing to
oscillate giving the machine maximum 15. (c) Rockwell suspension.
ground contact when it is working in
rough terrain. 16. Four drive pins encased in rubber
bushings.
3. On a skidder, the long section of the
frame is forward and the short section to 17. The front suspension units:
the rear because the engine and trans- 1. Support the vehicle.
mission are forward. Conversely, on a
loader the short section is forward and 2. Provide a steering axis to which the
the long section at the back. front wheel is attached.
4. The drive tandem housings oscillate 18. (a) nitrogen.
parallel with the frame and the front axle 19. Air suspension gives a soft ride. It is
pivots in the middle. used on buses, furniture vans and on
5. ... siderails . . cross members. some highway trucks.

6. (b) channel, box and I -beam. 20. Leveling valves:

7. Spring automatically control the air pressure

required by the load.
Rubber
maintain the frame at a constant
Hydro-air height.
Air
21. ... anchor structure.
8. (c) rate
9. The constant rate spring has an eye on
each end of the main leaf and therefore
its working length remains the same.
The progressive rate spring has only one
eye on the main leaf, and a cam bracket
on the rear, As the spring deflects. the
point of contact moves toward the cen-
ter, shortening the working length of the
spring and making it stiffer.
10. A progressive rate spring provides a sof-
ter ride when the vehicle is unloaded and
a stiffer spring when the vehicle is
loaded.
11. (d) a greater number of axles, springs
and tires.
12. (b) lowers the center of gravity for bet-
ter stability.
13. Torque leaves.

499
t-

6:206 WHEEL MACHINES

ANSWERS RIGID SUSPENSION

MAINTENANCE AND REPAIR
1. Install the steering safety bar.
2. Cleaning enables you to see problems in
their early stages.
3. Bolster pins. articulation pins, front axle
pins,
4, 1. Block the front wheels and support
the frame so it will not tip.
2. Support the counter weighted end
with a fork lift or similar lifting
device.
3. Neutralize the hydraulic pressure
before disconnecting the hydraulic
lines.
5. mounting brackets and pads.
worn bolt holes.
frame crack...
weld cracks.
center pins and bushings on ar-
ticulated machines.
bolster pins and bushings.

6. Oscillation bearing, thrust rings. 0-rings.

500
 WHEEL MACHINES 6:207

ANSWERS SPRING SUSPENSION 18. The adjustments or adjusting shims for

MAINTENANCE AND REPAIR the torque rods must not be changed. if
the adjustment is changed the universal
1. (d) check tire conditions and pressures. joint flanges on tandem axle vehicles
2. Rust streaks from stud holes. would be thrown out of alignment.
3 (d) at operating temperature. unloaded. 19 Because (1) spring saddles are solidly
and on level surface. fixed to the housing and (2) the front of
the rear spring is attached to the frame
4. Yes. Off-highway vehicles require more bracket by shackle pins.
frequent service because their work and
operating conditions are more severe. 20 All nitrogen pressure must be bled from
the cylinder.
5. Spring leaf breakage.
21. (a) Support the vehicle weight with a
Axle misalignment. jack.
Hard steering.
(b) Installcharging chucks on the
Abnormal tire wear. nitrogen valves of two cylinders
6. (a) loaded. (front or back) open the chucks.
7 A 45 degree angle distributes the cut and (c) Using a jack. lower the vehicle until
weld over a greater area than a cut made the rods are completely retracted
at right angles. and all the nitrogen is exhausted.
22. True.
8. Welding the frame corners and edges
encourages development of new cracks. 23 (b) change them as a pair. both front or
both rear.
9. False.
10. stencil marking.
"Brinell" marks.
"H" stamped on the upper face of the
rail near the rail end.
11. Drill a hole at the starting point of the
crack.
12. They provide a reduced heat affected
zone. increased flexibility and reduced
stress concentrations.
13. True.
14. The heat from the torch will weaken the
heat-treated beams.
15. Loose U-bolts.
Metal fatigue.
16. Measure from the straight edge to the:
1. connecting tube centers.
2. front-rear axle centers
3. back-rear axle centers.
Also measure (4) the distances between
the axle centers.
17. True.

501
6:208 WHEEL MACHINES

TASKS WHEEL MACHINE SUSPENSION 3. If a truck with hydro-air suspension is

available. check the cylinders for any
RIGID SUSPENSION signs of leakage or damage and retorque
(GRADERS AND LOADERS) the mounting bolts. (See the service
manual.) With the assistance of a jour-
Daily, Routine Maintenance Checks neyperson check for correct piston ex-
On a grader or loader: tension and pressure. Adjust if needed.

1. Check for zild tighten any loose suspen- Service Repair

sion mountings.
1. Using the correct jacking and blocking
2. Check the frame and mounting brackets procedures. raise a truck to a height that
and plates for cracks or other damage. will allow removal of the suspension unit.
Report any service repair needed. If the vehicle has hydro-air suspension.
follow procedures for bleeding down the
Service Repair gas charge before removing the air
On a grader or loader. using the correct tools. suspension.
lilting equipment and procedures outlined in 2. Remove the suspension unit.
the service manual:
3. Inspect the frame. cross members. and
1. Jack and securely block the machine (On suspension mounts for wear. cracks. loose
articulated machines insert the steering rivets and other damage. Make any minor
safety rod.) repairs: report any major service repair
2. Remove from their mountings the drive needed.
housings on a loader or the tandem 4. Remove the wheels and disassemble the
housings on a grader. suspension unit by removing, for example:
3. Inspect the mounting brackets for cracks springs, spring saddles.
U-bolts.
or damage and make any necessary walking beams. torque arms and
repairs. shackle pins and bushings.
4. Reinstall the housing. 5. Inspect the suspension components for
wear and damage. Write a parts list. Make
SPRING SUSPENSION (ON-HIGHWAY AND any necessary repairs or replacements.
OFFHIGHWAY TRUCKS)
6. Reassemble the suspension unit including
Daily, Routine Maintenance Checks the wheels. Install the suspension unit.
1. Check hangers, U-bolts. springs, spring 7. Lower the truck. Check and adjust the
saddles. walking beam bushings. torque alignment and lubricate where necessary.
arm bushings. shackle pins and bushings If the truck has hydro-air suspension. un-
(if equipped) for looseness. wear. cracks. der the assistance of the journeyperson
or other damage. Make any minor repairs: apply the gas charge to the specilleo
report any major service repair needed. pressure and suspension height.

Scheduled Maintenance Checks

1. Clean suspension parts and check the
frame, cross members and suspension
mounts for cracks, loose rivets or other
damage. Make any minor repairs; report
any major service repair needed,
2. Consult the service manual on suspension
alignment. Park the truck on a level floor
area. and using a tape measure.
straightedge and string line, check the
alignment of the suspension. If the
suspension is misaligned. adjust it with
the assistance of a journeyperson.
 TIRES, RIMS AND WHEELS 6:209

TIRES There are two general types of tires: over-the-

road tires and off-the-road tires. Over-the-road
INTRODUCTION tires are made for speeds over 48 km/h (30
mph) on highways. These tires flex quickly
This unit does not try to make you a tire ex- and generate a substantial amount of heat.
pert. but rather tries to give you a working Off-the-road tires are made for speeds under
knowledge of tires A mechanic should know 48 km/h on rough off-highway surfaces. They
how tires are constructed and how they are very durable so as to withstand the shocks
operate He should also be able to recognize of such obstacles as rocks and stumps. (Note
types of abnormal wear patterns and be able that some tires will fall between these two
to point to the steering. suspension, or brake types. having characteristics of both.) Service
problem that is causing the wear. Note that of over-the-road tires is usually done at tire
although an attempt has been made to use the shops. whereas many off-the-road tires are of-
most common tire words. tire terminology is ten serviced in the field.
not standardized in the industry, so some of
the words used here may be different than TIRE CONSTRUCTION
those of a given tire manufacturer.
Tires either have inflatable inner tubes (Figure
Purpose Of Tires 6-290) or are tubeless (Figure 6-291). In
tubeless tires, air is sealed between the rim
The general purpose of tires on wheel and tire casing. Tire casings for both tube and
vehicles is similar to the purpose of tracks on tubeless tires are similarity constructed. Basic
a crawler machine Tires must' tire parts are illustrated in Figure 6-292 and
support the machine are discussed below.
give traction
provide flotation
absorb or cushion shocks
provide a replaceable wear surface

FLAP
WHEEL LOOSE LOCKING
DISC FLANGE RING

TUBE
TIRE (6-290) TUBE TIRE
Courtesy of Fotesione Canada Inc

504
 6:210 TIRES, RIMS AND WHEELS

Courtesy 0 Firestone Canada Inc.

(6-291) TUBELESS
TIRE

TREAD
.
4.tr;'.714-44:4-'` _

.41-------TREAD SHOULDER

BODY PLIES

VALVE STEN

AIR CONTAINER

BEAD

X2534

(6-292)
Courtesy of John Deere Ltd.

505
 TIRES: RIMS AND WHEELS 6:211

Bead range. Load range. discussed later. gives the

range of the load :I tire will carry at its
Tire beads are strong bundles of wire that an- maximum inflated pressure.
chor the tire (i.e., the plies) to the rim. They
maintain the tire's shape, and its fit to the rim.
Tires may have one or more bead stacks.

Body Plies
Plies are layers of rubber-cushioned cord or
fabric that make up the body of the tire. The
strength built into the plies retains the air
pressure that supports the load and cushions
the shocks. Each cord in each ply is
completely surrounded by a resilient rubber SMALLER LARGER
compound. and each ply is insulated from the CORDS CORDS
next by a layer of the same compound.
The cord material may be made of cotton,
rayon, nylon, polyester, or other materials.
Rayon and nybn have been the most popular,
but recently more and more tire cords are
being made with polyester.
Tires have different numbers of plies. Tires for
4-PLY TIRE 2PLY TIRE
automobiles, station wagons and light pick-up X*535 (6_293) FOUR PLY RATED
trucks have two. four or six plies. Tires for
large highway trucks have from six to 14 plies Courtesy of John Deere Ltd.
and tires for large off-highway equipment can Types Of Ply Construction
have up to 20, or more, plies.
Bias Ply
Ply-Rating
Standard tires have a bias ply construction.
Ply-rating indicates the strength of a tire, but Bias means that the ply cords run from one
does not necessarily tell the number of cord tire bead to the other at an angle. Alternate
plies the tire has. For example, a tire with a plies run at diagonals to one another (Figure
four ply rating may only have two plies. The 6-294). Bias play construction gives rigidity to
four ply rating means that the two plies have both the sidewall and the tread. Two disad-
added strength and will carry the load of a tire vantages of bias ply are (1) the layers of ply
that has four standard plies (Figure 6-293). All tend to work against one another creating a
off-the-road tires are ply-rated. Automobile heat which can be a problem at high speeds.
and truck tires used to have a ply-rating but and (2) bias ply tends to cause the tread to
are now identified by what is called a load tighten or squeeze at the road surface in-
creasing tire wear.

Belts

BIAS PLY BELTED BIAS PLY BELTED RADIAL PLY

X2536 (6-294) Courtesy 01 John Deere Ltd.

506
6:212 TIRES, RIMS AND WHEELS

Belted-Bias Ply Both bias ply and radial ply tires are used on
heavy duty equipment. but the trend is
Belts are added to a bias ply construction to towards radial ply. Note that the type of ply
make a belted-bias ply tire. The belts are com- construction of a tire is often marked on the
posed of very low angle cords; they surround tire: B for bias - belted; R foi radial; and D for
the tire body underneath the tread. This bias (diagonal).
construction gives rigidity to both the
sidewalls and the tread. The belts reduce Wire Reinforced Ply
tread motion during contact with the road and
thus improve tread life. Some big tires for earthmoving and other
equipment. have a layer of wire between the
Belted-Radial Ply tread and the body of the tire (Figure 6-295).
This protective layer of wire keeps most cuts
On a belted-radial ply tire the ply cords run from penetrating the tire body. It also keeps
across the body from bead to bead at almost a tread cuts from enlarging and holds them
right angle. Fairly rigid belts composed of closed so that sand and dirt will not enter and
steel or fabric cords surround the tire body cause separation.
underneath the tread. As with belted-bias
tires. the belts recipe tread motion during SHREDDED
contact with the road, and thus improve tread 7NyHRE UNDERTREADI
life. Radial ply construction gives better sup-
port to the tread than the other two types of
ply. Three advantages are c r red for radial
tires:
'1. They generate less heat when properly in-
flated.
AN
YLON BODY
2. A broader base of rubber contacts the '1/4
road making the tire less likely to skid,
especially at corners.
3. They wear better because they don't
cause the tread to squeeze.
IV
(6-295) WIRE- REINFORCED CONSTRUCTION. OF
HEAVY -OUTY TIRE
Courtesy of John Deere Ltd.

Sidewalls
Sidewalls are the rubber coverings on both
sides of the body. They are made to flex and
bend without cracking during both ordinary
deflection and extreme sudden shock.

Tread
The tread is the part of the tire which contacts
the road. It must provide traction, give long
wear and resist cuts. Tire treads have many
patterns and depths for different types of ser-
vice. Examples of tread for off-the-road tires
are given in Figure 6-296 and for over-the-
road tires in Figure 6-297.
/160
2r, 'elUe

Ribbed tires are found mainly on scrapers and

ea,
.
motor graders. The deep grooves resist any
o
I: .4. side thrust. and the heavy lugs on the
f_ sidewalls give added protection.
47;

(6-296)
Courtesy of Caterpillar Tractor Co
5.07
 TIRES, RIMS AND WHEELS 6:213

Traction tread tires are found on many

scraper tractors and wheel dozers, and on the
front and rear of some motor graders. The
angled bats fire designed to force mud and
dirt oic to 4tolfr.3:e better traction. The wedge
shapAt of the bros helps clean the tread when
it is riot in coniac) with the ground.

(6-296)
Courtesy of Caterpillar Tractor Co.
Rock tires are used on scrapers, wheel
loaders and trucks working in rock quarries.
The bars on these tires provide excellent
resistance to cutting and bruising by rocks.
The larger bars give increased tire-to-ground
contact and much better weight distribution.

(6-296)
Courtesy of Caterpillar Tractor Co.
Flotation tires are used primarily on free
rolling wheels or for oeneral traction. They
are a very wide tire and thus distribute the
vehicle weight over a broad surface area. The
ugs are placed close together to give a
reasonably smooth ride.
4

(6-296)
Courtesy of Caterpillar Tractor Co.

508
6:214 TIRES, RIMS AND WHEELS

V-treads are designed for traction in soft

material. Graders and agricultural machinery
use V-treads.
a:-
A

I))

(6-296)
Courtesy of Caterpillar Tractor Co.

/ . _A"5"--
Apdp.-14b.
-.1

riA ,6 ..,
(6-297) OVER-THE-ROAD TIRE TREADS
Counesv of Fire Slone Canada Inc

509
 TIRES, RIMS AND WHEELS 6:215

Tread Directional Arrows Rims

Drive wheel tires on many machines must be Rims are the part of the wheel that support the
mounted to rotate in a certain direction for tire. Rims are discussed in more detail later in
besl traction. For this reason. directional this section.
arrows are often stamped on the sidewall to
show forward rotation (Figure 6-298). This is TIRE SIZE AND LOAD RANGE
most important on V-tread tires where the V
pattern must point downward when viewed Tire Size
from the front.
The size of a tire is indicated by:
the width of the tire
the tire's rim size.
Figure 6-299 shows a typical size marking on

E> the sidewall of an off-the-road tire. The 24.5 is

the section width of the tire (in inches) when
mounted on its recommended rim. The 32
gives the nominal diameter in inches of the
ARROW SHOWS
rim (Figure 6 -299). Note. if metric
FORWARD measurement is used. the figures will
ROTATION represent centimeters.
V-TREADS
SHOULD P.)INT
DOWNWARD
WHEN VIEWED
FROM FRONT
X2540

(6-298) DIRECTIONAL ARROWS ON TIRES

Courtesy of John Deere Ltd
(6-299) NORMAL SIZING
Tubes
Courtesy of John Deere Ltd
The function of the inner tube in a tube tire is
to retain air. inert gases. or liquid under
pressure within the tire case. When inflated it
is donut shaped and fits perfectly inside the
tire casing. Tubes are made of the same type
of rubber as the tire. A valve stem is
vulcanized to a spot on the tube's inner cir-
cumference. providing a means of inflating
and deflating the tire.
Flaps
On tube tires. flaps give puncture protection
by shielding the tube from contact with the
rim and tire beads.

Tubeless Inner Liners

(6-299)
Tubeless tires have a thin rubber liner that
Courtesy of John Deere Ltd
coats the inside of the tire from bead to bead.
The liner. like an inner tube. retains the air.
The rubber liner reduces the overall weight of
the tire by eliminating tubes and flaps: it is
also easier to maintain than an inner tube.

510
6:216 TIRES, RIMS AND WHEELS

Another system used by some manufacturers Load Range Of The

to show tire size is to give a figure on the
sidewall that represents the ratio of the height Load range. as stated earlier. is the load limit
to the width of the tire donut (Figure 6-300). a tire can carry at its maximum pressure. Load
The figure. 78, for example, weans that the range has replaced ply rating as a means of
tire donut is 78 percent as high as it is wide rating on-highway tires. Load range is in-
(i.e.. the donut width is about one quarter dicated by a capital letter A. B. C. D. E. F. G
bigger than its height). Tires are available in and so on. Each letter stands for a certain
four height-weight ratios: 83. 78. 70. and 60. load and inflation Omit. For example. a load
range of F means that the tire has a load limit
of 1500 lbs. at 32 p.s.i. In the metric system
kilograms (kg) are used instead of lbs. and
kilopascals (kPa) in place of lbs. per square
inch.

FACTORS IN SELECTING
OFF-THE-ROAD TIRES
The type of tread. as stated earlier. is a factor
in selecting tires to do a job. Two other fac-
tors are load size and machine speed. which
(6 -3Q0) together give the Ton-Mole-PerHour Rating
(TM PH) that is used in choosing a tire of
suitable size and strength. The TMPH for a
large earthmover would he found in the
following way (Courtesy of Caterpillar):

(weight (weight Obtain the weights in tons carried by the tires

empty) loaded) . Average
Tire Load
when the machine is empty. and then when it
is loaded. These two weights should be
2
totalled and divided by two. This figure is the
average lire load in tons.

(cycles (miles An average speed is then obtained by

per day) per cycle) Average multiplying the cycles per day (that is. the
number cf working Speed number of trips from the cut to the fill and
hours per day return) by the distance travelled per cycle in
miles to give the total miles travelled per day.
The product is divided by the hours in a work
day to obtain the average speed.

(average (average = T.M.P H. The average speed is multiplied by the

speed) tire load) average lire load and the product is the Ton -
Mite- Per -Hour rating.

RIMS AND WHEELS

Rims
Tires are mounted on rims. Rims may be part
of or separate from the wheel; those separate
from the wheel are called demountable rims.
Most automobiles and heavy duty vehicle r"as
and wheels are made of steel. In the past few
years, however. other metals such as
magnesium (automobiles) and aluminum

5.11
 . TIRES, RIMS AND WHEELS 6:217

(automobiles and on-highway heavy duty

trucks) are being used for rims as well Rims
and wheels differ in size, shape, method of
mounting and in whether they are made for
tube or tubeless tires. Note that tires and rims
must be matched, i.e., rims must be used with
the correct size and type of tire. Many tire
failures have been caused by mismatching
tires and rims.

TYPES OF HEAVY DUTY

WHEELS AND RIMS
There are three main types of heavy duty
wheel-rim combinations.
1 Cast Spoke Wheel with Demountable Rim
wheel and rim separate,
2. Disc Wheel and Rim wheel and rim
combined.
3. Split Disc Wheel and Rim similar to
disc wheels except that the wheel and rim
is made in two halves. The two halves are (6-301)
joined together near the center by bolts
located just outside the center mounting
flange holes. These wheels are not dished
like disc wheels and are used only for
single wheel applications.
Cast Spoke Wheels and Demountable Rims
Figure 6-301 shows a typical cast spoke wheel
and demountable rim. Note that the wheel and
hub are integral parts. The rim slides over the
wheel and is retained by clamps (lugs) and
nuts. The lugs fit over hub studs and grip the
outside edge of the outer lip of the rim as
shown in the figure.

(6-302) TYPICAL FRONT MOUNTING ON

CAST WHEELS
Courtesy of Konworth Truck Co

(6-301) Courtesy of DaytonWatiher

512
6:218 TIRES, RIMS AND WHEELS

Figure 6-303 Shows a complete spoke wheel 1 Rim Spacer

assembly including the brake drum. Note how 2 Rim Nut
the wheel is attached to the brake drum. Rim Clamp
When a tire on a spoke wheel is changed only 4 Rim S
3
the rim and tire are removed (Figure 6-303). 5 Bearing Cup Outer
6 Bearing Cup Inner
7 Wheel
8 Brake Drum Nut
9 Brake Drum
10 Brake Drum Bolt
11 Olt Slinger Optional
12 Hub Cap Optional
7
ult

oo

9
6
(6-303) Courtesy of DaytonWalther

Dual tires are also mounted on cast spoke

wheels; two rims and their tires are mounted
on a single wheel (Figure 6-304). The rim
mounting surface on the dual wheel is wider
to accommodate the two rims. Lugs (Figure 6-
305) grip on the inner edge of the outside rim
and hold both rims to the wheel. The rims are
placed on the wheel so that the valve stems
are 180 degrees apart and don't interfere with
one another. The driving lugs (Figure 6-306)
on the rims are located next to a spoke for
both curb and roadside installations; this
prevents rims from slipping on the wheel and
possibly shearing the valve stems. CLAMP WHEEL
(6-304)
Note in Figures 6-304 and 6-305 that (1) both
TYPICAL DUAL MOUNTING ON SPOKE WHEEL
rims overhang the wheel by most of their
width and (2). a rim spacer is placed over the Courtesy of Mack Truck Limed
wheel between tie two rims to prevent the
tires interfering with one another when the
vehicle is loaded.
tilrt WHEEL RIM
11
\\I. ,,,,,... , A
`'''''''1/410...,..,n 40"%.M.11'
**Ill WHEEL RIM SPACER 111116N6kNill,\Nr.
/a/ / I A,s dy,
1....... '1 Oh, ,,,,

°###. ---....4-- liS\NWKW061.

.. WHEEL RtM
RIM CLAMP NUT
RIM CLAMP
REAR
Courtesy of General Motors Corporation
(6-305) CAST WHEEL MOUNT

513
 TIRES, RIMS AND WHEELS 6:219

Proper Positioning of Rim Drivers

Curb side trailer and front wheels Rotate
rims clockwise until rim driver contacts wheel
bevel/clamp.
Road side trailer and front wheels Rotate
rims counterclockwise until rim driver c on-
tacts wheel bevel/clamp.
Curb side drive wheels Rotate outer rim
clockwise until rim driver contacts rim clamp.
If wheel does not have slots. rotate inner rim
counterclockwise until rim driver contacts
wheel bevel.
Road side drive wheels Rotate outer rim
counterclockwise until rim driver contacts rim
clamp. If wheel does not have drive slots.
rotate inner rim clockwise until rim driver con-
tacts wheel bevel. (6-306)

Disc Wheel and Rim

A typical droppedcenter or dished disc wheel
and rim is shown in Figure 6.307. The disc
wheel and rim. unlike the cast spoke wheel
and demountable rim. is made with the wheel
and rim joined together. This particular one is
a ten stud wheel for a tube tire. The number of
stud holes vary with size and load capacity of
the rim.
To mount a tube tire on a disc rim. the tire
and tube are slid onto the rim. held in place by 1111111/
the flange and locking rim (Figure 6-308). then
inflated. To mount a tubeless tire on a disc rim LOCKING
WHEEL LOOSE
(Figure 6 -309). the beads of the tire must be DISC FLANGE RING
pryed over the rim edge as there is no locking
(6-308)
ring arrangement like on the tube rim. The tire
Courtesy 01 Firesione Canada inc
is then inflated through a special valve stem
fixed in the rim.
Mfoseb

(6-309)
Courtesy of Firestone Canada Inc

(6-307)
Courtesy of Budd Company

514
6:220 TIRES, RIMS AND WHEELS

Disc Wheel Mounting

SINGLE
Disc wheels can be either single or dual
mounted (Figures 6.310. 6.311). Several nut
arrangements are available to hold' the wheel Single
to the hub. but the most common is the ball Cap Nut
seat nuts. generally referred to in the trade as 1

Budd nuts. (Budd manufacturers ball seat

nuts.)

Inner Dual
DUAL Cap Nut

(6.310)

Courtesy of Budd Company

Outer Dual
Cap Nut
AI

(6.311)
Courtesy ol 13urid Company

515
 TIRES, RIMS AND WHEELS 6:221

For single front-wheel mounting single nuts Wheels

are used as shown in Figure 6.312. The wheel
is placed over the hub studs. with the dished
surface of the rim facing outwards. The nuts
are then threaded on to the studs and
tightened to secure the wheel.
For dual. rear-wheel mounting an inner and
outer cap nut arrangement is used (Figure 6-
312). The inner wheel with the dished part
facing outwards. is placed over the hub studs.
and the inner cap nuts (Figure 6-313) are lob
threaded to the hub studs. then tightened to
secure the wheel. The outer wheel is then
placed over the inner cap nuts with the dish of
FRONT REAR
the rim facing the inner wheel. The outer cap
(6-312)
nuts (Figure 6-313) are tightened to the outer
Courtesy 01 General Motors Corporation
threads of the inner cap nuts. securing the
outer wheel in place. The inner-outer nut
arrangement (Figure 6-314) permits both
wheels to be mounted to the same hub stud
and allows the outer wheel to be removed 1\\17\1;\1;\\Co re"
without disturbing the inner one.
INNER THREAD firWRENCH
SURFACES

OUTER THREAD
(6-313) OUTER CAP NUTS
Courtesy 01 Budd Company

(6-313) OUTER CAP NUTS

Courtesy 01 Budd Company

The Budd Mounting is a fixed rim (demoun-

table-at-the-hub) wheel. This type assembly
provides for positive torque transfer through
the mating surfaces which are held in com- OUTER DUAL WHEEL
pression with studs and cap nuts. This is the OUTER CAP NUT
simplest. strongest and most effective moun-
ting available.

Courtesy of Budd Company

INNER CAP NUTS
HUB. DRUM AND STUD ASSEMBLY
INNER DUAL WHEEL (6-314)

516
6:222 TIRES, RIMS AND WHEELS

Lett and Right Hand Threads On Studs and

Nuts
SINGLE WHEEL CAP NUTS
The retaining nuts and corresponding studs
for disc rims have the usual right-hand thread
for the right-side of the vehicle, but use left-
hand thread for the left-side. Markings on the
end of the stud will easily Identify left (L) or
right (R) threads (Figures 6416, 6416). The
nuts are also marked. Inner cap nuts are
marked on their square end and the outer nuts
on top (Figure 6 -315). Another way of iden-
tifying left-hand threaded nuts is by slight cut (6 -315)
marks at the corners of the nuts (Figure 6- LEFT-HAND THREAD CAP NUT
315).
Courtesy of Budd Company
Split Disc Wheel and Rim
(6-315) WHEEL STUD
Special wheels having a two piece split rim
construction are :nade for vehicles such as
fork lifts and skidders. These wheels have a
double set of nuts: one set hclds the wheel on
the hub while the other set holds the two
wheel halves together. Caution must be taken
when removing a split rim wheel. if the
nuts that hold the wheel together ale
mistaken for the hub nuts, and are taken off
first, you could be seriously injured by the rim
flying apart. If ever in doubt as to which nuts
hold the wheel halves together and which
hold the wheel to the hub. deflate the tire
before removing any of the nuts. This will
eliminate any danger.
There is no standard method of marking split
rim nuts and hub nuts. On some machines
both sets of nuts are the same, and the service (6-316)
manual has to be consulted to find out which
Comtesy of Kenworlh Truck Co.
is which. Other machines identify the sets,
One method is to insert a cotter pin through
the outer end of the rim half bolts. Another is
to make the two sets of bolts a different size,
-........,1.._
as is shown in Figure 6-317.

-Ifiti;c,-4(1
4.....t...-

(6-317) ARim half nuts hold split

rims together. 13Hub nuts hold
wheel to hub.
Courtesy of Clarke Equppmenl Company

5j7
 TIRES, RIMS AND WHEELS 6:223

BALLAST 15 and 20 pounds per gallon for different size

machines.
Modern oll-the-road machines have adequate
horsepower. but the machine weight by itself
may not be sufficient to give full traction and Advantages claimed for dry ballast:
drawbar pull. Under only its own weight, the
machine's wheels may slip excessively and 1 Gives 20 to 30 percent more traction with
cause tires to wear rapidly. Extra weight in the less tire wear.
form of ballast can give the machine the trac- 2. Reduces the inherent bounce in rubber
tion it needs and also reduce tire wear. Farm tires. giving smoother operation.
tractors are one example of a machine that
uses ballast. 3. Has no freezing problem because it is dry
material and is treated to resist moisture.
How much ballast does a machine need?
Enough to give good traction and yet allow a Disadvantages of dry ballast:
small percentage (10-15%) of wheel slippage.
There are two types of ballast: liquid and dry. 1. Has higher initial cost.
2. Requires outside servicing with special
Liquid Ballast equipment.
Liquid ballast Is usually a mixture of water and 3. Looses ballast if tire and tube or valve
calcium chloride. The calcium chloride adds fails.
weight to the water and prevents it from
freezing. The mixture is pumped in until the 4. Causes more heat build-up.
tire is 75 percent full (Figure 6-318). Air is then
pumped into the remaining space. A tire is Cast Iron Ballast
never 100 percent filled with liquid ballast be-
cause it would be inflexible and couldn't
Cast iron weights can also be bolted to the
properly absorb shocks (i.e.. water doesn't frame or wheels to give a machine ballast.
compress). Filling a tire with liquid ballast is The general practice is to first add liquid
usually done in a tire shop because most ballast to tires and then add cast iron weight
as required.
heavy duty shops aren't equipped to do it.
Caution: Extra precautions must be taken
AIR COMPRESSES WATER CAN'T BE when removing ballast weighted
LIKE A CUSHION COMPRESSED wheels. Be sure to use adequate
slings or lifting devices.

....1.

CORRECT - 75% FULL INCORRECT 100% FULL

(6-318)
Counesy 0 Jorm Deere Lid

Dry Ballast
Dry ballast. although not as common as liquid
ballast. is also used for weighting tires. Some
dealers are equipped to install dry ballast and
a few manufacturers are installing dry ballast
at the factory. Normally. tires are filled to 87 to
95 percent of capacity with a ballast powder
made of a clay. limestone and barium sulfate
compound. Dry ballast comes in weights of 10.
518
6:224 TIRES, RIMS AND WHEELS

TIRE TRACTION AND PROTECTION

DEVICES

Chains.
Mud or snow lug tires. under certain cir-
cumstances. may not be sufficient to give a
machine the traction to keep it moving. In this
event traction devices are required. The most
common traction device is skid chains. Skid
chains are used on two and four wheel drive
vehicles operating either on or off the high-
way. Even tandem drive vehicles will oc
casionally require chains.
Truck and bus chains for traction in snow. ice.
and mud are illustrated in Figure 6.319. Figure (6-320
6.320 shows skidder chains. Courtesy of International Harvester

(6-319) (6.319) (6.319)

Courtesy of Dominion Chain Co Courtesy of Dominion Chain Co Courtesy of Dominion Chain Co

Chains are used as protection devices as well

as for traction. Rock quarry work is extremely
hard on tires. To protect tires operating in
quarries special chains are made that it over
the entire tread and sidewall. The chain mesh
protects the tread from abrasion. cuts and
bruises. Quarry chains are expensive. and so
their cost and the added life they give to tires
must be weighed against simply running the
tires to destruction.

519
 TIRES, RIMS AND WHEELS 6:225

Beadiest Tires
Caterpillar has developed another trac-
tion/protection device called a beadless tire
(Figure 6-321). made for loaders working in
rock. It is a specially designed one-piece tire
having an oval air chamber called a carcass.
The carcass is one ply, and instead of beads
has a framework of helically wound cable to
give it support. The carcass is mounted to a
unique two-piece split rim. A replaceable,
cable-reinforced rubber belt encircles the
outer circumference of the carcass. The belt
is held in place by air pressure in the carcass
and by matching grooves on the inside of the
belt and on the outside of the carcass. Steel
shoes bolt directly to anchor plates moulded
to the mounting belt. The shoes. belt and car-
cass are all replaceable.

(6.321) 1Two piece rim. 2Carcass. 3Mounting Courtesy of Caterpillar Tractor co,
belt. 4Shoes. 5Center mounting bolt,

5go
6:226 TIRES, RIMS AND WHEELS

QUESTIONS TIRES, RIMS AND WHEELS, 15. Weight can properly be added to a
BALLAST, TRACTION DEVICES machine by:

1. List five purposes of tires. (a) using flotation tires.

2. What are the two general types of tires (b) piling up rocks on the machine.
and what are the two types of tire con- (c) filling the tires with liquid or dry
struction? ballast.
3. What do the allowing letters and num- (d) inflating the tires.
bers refer to with respect to tire sizing:
H.R. 78-15? 16. The recommended maximum amount of
liquid ballast that can be put into tires is:
4. What is the purpose of tire beads?
(a) 50% calcium chloride. 50% air.
5. True or False? Ply-rating gives the
strength of the tire. but does not (b) 75% calcium chloride. 25% air.
necessarily give the number of cord (c) 90% calcium chloride. 10% air.
plies.
(d) 100% calcium chloride, no air.
6. What is the main advantage of belted-
bias and radial- belted tires over bias ply 17. What precaution must be observed when
tires? removing ballast weighted wheels?
7. Drive wheel tires with a V-tread pattern 18. Tire chains on a grader working in win-
must be mounted for forward rotation so tery conditions would be needed for
the V-pattern points: Tire chains on a
(a) downward as viewed from the front.
loader in a rock quarry are used for

(b) downward as viewed from the rear. 19. What does a beadless tire have ea place
(c) upward as viewed from the front. of tread?
(d) either (a) or (c).
8. True or False? Tire flaps are needed in
tubeless tires to help seal the tire at the
rim.
9. What two other factors are considered
besides tread design when selecting off-
the-road tires?
10. How does a cast spoke wheel with a
demountable rim differ from a disc
wheel?
11. Briefly explain how the method of
retaining the rim on a cast spoke wheel
differs from retaining the rim on a disc
wheel.
12. What precautions must be observed
when removing split-rim wheel?
13. How are the double nuts and studs used
to attach disc wheels marked to indicate
thread direction?
14. If a machine working in off-theroad con-
ditions has insufficient weight, excessive
of the tires.will result.

521
 TIRES, RIMS AND WHEELS

MAINTENANCE AND SERVICE REPAIR

ON TIRES, RIMS AND WHEELS

DAILY, ROUTINE CHECKS

ON TIRES
1. Check the tires for cuts. gouges. or any
other damage that would make the tires
unsafe to operate.
2. Remove any rocks that are embedded in
the treads. If left in. the rocks can work
their way into the plies and weaken them.
3. If rubbing marks are found on a side wall.
misalignment or severe suspension wear
could be indicated. Find out what caused
the rubbing.
4. Abnormal tread wear is usually a sign of
.misalignment
5. Check the depth of tire treads. Any
vehicle operating under the Bureau of
Motor Carrier Safety must have at least
one-eighth inch of tread depth on the front
tires. When front tire tread wears below
one-eighth inch. the tires can be rotated
to driving axle or trailer axle positions un-
til one-sixteenth inch of tread depth
remains. Tires with less than one-
sixteenth inch tread must be removed
from service.
6. Check for any part of the machine that
could damage or cut a tire a bent fen-
der. a bolt. a broken support part. a bent
rim.

7 Check tire pressure. A quick method used

by those who have a feel for a properly in-
flated tire is to hit the tires with a bar.
From experience they can tell if the
pressure is right. However. the only sure
way to check tire pressure is with a tire
gauge.
Maintaining the correct air pressure is an im-
portant tire maintenance procedure. Some of
the reasons for closely watching tire pressure
are shown on the following page.

522
6:228 TIRES, RIMS AND WHEELS

Effects Of Incorrect Inflation ched with a correctly inflated tire on one side
of a tandem. the under inflated tire would slip
Attention to tire pressures on the front wheels for those 22 revolutions because it must travel
is as important to the safe control of the truck at the same speed or revolutions per mile as
as is tire balance and front-end alignment the correctly inflated tire. During the first
With lower pressure. tire contact area with the
1.000 miles it will slip 13-1/2 miles. and after
road increases. More contact area means 10.000 miles it will have slipped 135 miles. Tire
more resistance against rolling and poorer
fuel mileage. If front tire pressures are treads have been known to be ground off in
unequal. the wheels will tend to steer to the less than 10,000 miles.
side of lowest pressure causing extra tread
wear. Such a steering pull may not be noticed Under inflation can affect more than the tread
when driving with power-assist steering until of a lire. Under inflated tire: flex ,xcessively
the brakes are applied. During braking ap- and this results in high internal tire tem-
plication the tire with the lowest pressure will peratures that can cause premature tire
pull the truck to its side. A sudden. hard ap- damage such as flex breaks. radial cracks
plication of the brakes on a slippery road and ply separation. Over inlfation is also bad
might start a tractor-trailer rig lack-knifing. for tires. It prevents full contact of the tire with
the ground causing excessive wear at the
Consider the change in the overall diameter center of the tread. An over inflated tire is too
01 two similar tires with different tire pressures rigid and is more vulnerable to snags, cuts.
(and constant load) (Figure 6-322) The lower and punctures. Figure 6-323 illustrates over.
the air pressure the shorter the overall
under and proper inflation. Note that a proper
diameter becomes Since the overall diameter inflation permits all of the tread to contact the
is smaller in the under inflated tire. it will ground, but doesn't allow the tire to flex ex-
travel more revolutions in a mite (i.e., faster at cessively.
constant speed). in this case about 22 extra
revolutions. If this underinflated tire was mat-

I
OVERALL
DIAMETER
40"
I
39.3/8"

1 I
80 P Si 50 P S I.
(6-322)

OVER INFLATION UNDER INFLATION PROPER INFLATION

WEAR AT CENTER OF WEAR AT THE TWO SIDES EVEN WEAR
TIRES OF THE TREAD
(6-323) Courtesy of John Deere Ltd

523
 TIRES, RIMS AND WHEELS 6:229

SERVICE REPAIR OF TIRES AND RIMS The Heat

Thissection is mainly concerned with Under normal working conditions a tire will
removing and installing wheels and with heat and its air pressure will increase. If air
wheel. rim and stud damage. It does not deal pressure is taken during a shift. the reading
with changing tires because most tire work for will be higher than the air pressure really is. If
heavy duty vehicles will be done by tire the tire was then mistakenly bled tc bring it
specialists. down to specified pressure. it would be under
inflated. Tire pressure. therefore. must be
Removing Tires and Wheels checked on cold tires.

Jacking Precautions The best time to take tire pressures is in the

morning before the shift begins, after the tires
1. Regardless of how hard or firm the ground have had a chance to cool down overnight.
appears. put a good solid block(s) under However, some machines run for two or three
the jack. shifts in a' day and are not idle long enough
for the tires to cool. In this case get a correct
2 Block the lire and wheel on the other side cool tire reading. and then take a hot reading
of the vehicle before you place the jack in at least two hours into the shift. This hot
position Always crib up with blocks just in reading is what the tire pressure should be
case the jack may slip. when measured hot thereafter.
Removing Wheel Nuts Tires are built to take a certain amount of
heat. but too much heat can damage the
The correct way of removing wheel nuts is to structure of the tire. One of the factors.
first loosen all the nuts in the same pattern already discussed. that cause a tire to
that they are tightened and then to remove overheat is under inflation. Other factors are
them. overloading and high speed. Their effect on
When removing single and dual tire heat can be seen in the following
Caution:
cast spoke wheel rims and tires. statistics. The temperature of a tire with a nor-
loosen all nuts until they are ap- mal load at 60 MPH is approximately 212°F.
proximately flush with the end of When the speed is increased to 80 MPH. the
the stud. Then strike the clamps temperature will rise to 250'F. An overload of
with a hammer to loosen them from 20 percent will produce 250°F. at 70 MPH. This
the rim (Figure 6-324). This will may help to explain why many tires fail in the
prevent the clamps from flying off summer months.
the studs when the nuts are Overheating is especially damaging to large
removed. off-highway tires. Although big heavy duty
tires are built to take rough physical treat-
''ts.'1- ment. they cannot stand too much heat. Their
thick rubber construction has a tendency to
withhold heat. To avoid a damaging heat
buildup when driving an off-highway machine
on the highway. it should be stopped every 25
miles (or one hour) for a half hour to cool the
tires.
, ...
.. Tire Pressure Gauges
Two types of pressure gauges are usually
4141
available high-pressure and low-pressure
1 7031
for either dry or liquid testing. Always use
f Li' the proper gauge when checking pressure.
(6-324) CLAMP REMOVAL (DUAL SPOKE WHEEL)
High-pressure gauges will be used on most
truck and off-highway machine tires. Nor-
Courtesy of General Motors Corporation mally. high-pressure gauges are not satisfac-
tory for checking low-pressure tires because
the gauges are usually calibrated in five-
pound increments while low-pressure gauges
are calibrated in one-pound increments.

524
6:230 TIRES, RIMS AND WHEELS

It is most important that a gauge be accurate 2. Use a rubber covered steel hammer on
Accuracy can only be determined by rims and tires; it won't damage the rim or
checking the gauge against a gauge of chip off bits of metal that may cause injury
known accuracy. For this reason. keep one (Figure 6-327).
accurate gauge for the sole purpose of
checking the accuracy of the gauge normally
used. This practice is especially important
when working with low-pressure gauges.

Deflating and Inflating Tires

Tires should be deflated, if possible. before
removing them from the vehicle. To deflate
the tire. first reduce pressure by pushing in
the valve plunger. and then remove the entire
core to ensure complete deflation. (6-327)
Counesy of General Motors Corporation
Caution: When deflating a tire. keep your
eyes away from the valve, and 3. Do not attempt to correct side and lock
never place your body in front of ring seating by hammering a tire while it's
the rim (Figure 6-325). Also, never inflated or partially inflated. Remove all
attempt to unlock or remove a lock the air pressure first.
ring without first removing the
valve core. 4. If possible use a safety device such as is
shown in Figures 6.328 and 6-329 when in-
flating a tire:

(6-325)
Counesy 0 Mack Truck Ltd
Inflating Tires (6-328) SAFETY PRESS
ounesy of Mack Truck Co
1. Before inflating a tire make certain the rim
lock ring is seated to the full depth of the
groove. fits tightly all around. and is
securely locked (Figure 6-326). Improperly
seated rings are a main cause of rim
failure.

(6.326) (6-329) SAFETY CAGE

Counesy of Generai Motors Corporation comiesy 01 General Motors Corporation

525
 TIRES, RIMS AND WHEELS 6:231

5. if it is not possible to use a safety device Imagine a set of tandem axles, directly
use a sell attaching air chuck and stand connected by the prop-shaft. rolling on
behind the tire tread while inflating. eight tires all of a significantly different
radius. The rear axle will try to over-, Jr)
the lorward axle and the forward axle will
try to hold back the rear axle. The tires
will squirm and scrub. This is wheel fight.
It tries to wind up the prop shaft and twist
the axle shafts. Wheel fight causes the
ring and pinion gear teeth to grind under
extreme pre-.....-es and the differential and
bearings to work beyond their normal
limit. If these conditions are allowed to
continue, internal mechanical damage will
surely result.

How To Match Tandem Tires

The vehicle should be on a level floor.
carrying a correctly distributed capacity load.
Be sure all tires are the same size.
1. Inflate all tires to the same pressure.
2. Tire measurements:
A WARNING (a) The most accurate method of
measuring tires is to measure, with a
Use selfattaching air chuck and stand steel tape. the circumference.of the
behind tire tread while inflating. tires when they are on the rim and in-
flated (Figure 6-331).
(6-330)
Courtesy of Calerpdiar Tracior Co
6. The valve core is a spring-loaded check
valve in the valve stem. 'permitting in-
flation or deflation of the tube or tire. This
check valve. or core. is not intended to
hold the air during operation. The valve
cap is provided to seal the air in the tube
and tire. When the valve cap is tightened
on the stem. the sealing washer inside the
cap is pressed tightly against the top of (6-331) MEASURING WITH FLEXIBLE TAPE
the stem. preventing air leakage and Courtesy of Mack Truck Company
keeping dirt out. It is important, therefore. (b) Taking circumferences is difficult
that valve caps be used at all times. Note when the tires are on the vehicle. In
that most valve caps used for automobile this case measure the radius or the
tires are made of plastic and won't give a diameter of the tires. A large square,
seal. They only protect the core from dirt matching stick or string fine is
and contamination. suitable for this measurement (Figure
6-332).
SCHEDULED MAINTENANCE ON TIRES
Probably the main form of scheduled main-
tenance on tires is matching the tires. Tires
should be matched when put on a vehicle and
matched thereafter on a scheduled basis.
Mismatched tires can cause a lot of problems.
Consider this extreme example:
MEASURING WITH
MEASURING WITH A SQUARE MATCHING -STICK
9S.37
Courtesy of Mack Truck Company

526
6:232 TIRES, RIMS AND WHEELS

3. Mark the size on each tire with chalk and 2. Tires for construction equipment such as
arrange them in order of size. largest to larger wheel loaders or graders
smallest.
These tires and wheels are large enough
4. Mount the two largest tires on one side of to be dangerous if they fail over and thus
one axle and mount the two smallest on require a forklift or an overhead crane and
the opposite side of the same axle. It is sling to remove and to move them (Figure
advisable to allow only a half inch dif- 6-333).
ference in diameter between duals. or one
and a half inch difference between cir- 1

5.
cumferences.
Mount the four other tires on the other
axle in the same manner. If the vehicle
I 1
has tridem axles. the same system is used:
arrange the tires in order of size. The two
largest and two smallest go on one axle,
the next two largest and smallest go on
the second axle, and the remaining four
go on the third axle. This system of mat- a
ching has two benefits:
(a) each running pair is closely matched.
(b) the total rolling circumference of the
four tires on an axle will be ap- 09i05X1 '
proximately the same for all axles. (6-333)
Courtesy of Caterpillar Tractor Co
6. Test run the vehicle to get accurate rear
axle lubricant temperature readings on 3. Tires and wheels for large off-highway
the two axle lubricant temperature haulers in the 100-200 ton range
gauges. Vary tire air pressure. within the These tires and wheels are very large and
tire manufacturers recommended range. heavy; a forklift (Figure 6-334) with a tire
so that the lubricant temperatures of both attachment is generally used to remove
axles are within 30 F. of each other and them from the machine. Slings are also
not in excess of 220 F. This will usually used.
result in uniform tire loading and good tire
life.
Tire Rotation
Generally speaking. if a tire is broken in on
the front wheels and then moved to the rear
axle(s). it will have a longer overall service
life. For this reason. some fleet owners will
rotate tires from front to rear wheel positions
on a scheduled rotation plan. The plan will
vary depending on the type of vehicle and the
size of tires. Note that any tire that has been
recapped or regrooved should not be used on
the front of a vehicle. Heavy duty tires and
wheels can be put into three size categories (6-334)
according to the way they're handled. Courtesy of Caterpillar Tractor Co

1. Over-the-highway truck tires Take special precautions with ballast

weighted tires. Injury could result from a
These tires can be lifted off studs and tire that looks like it could be handled by
rolled out of the way by 'land. Wheel hand but can't because of the extra
dollies are also used for handling highway weight of internal ballast. If you do not
truck tires. know whether a tire has internal ballast.
check the air valve. Internal ballast
requires a special type of valve. Aisu be

52
 TIRES, RIMS AND WHEELS 6:233

careful of external weights attached to the

wheel by the wheel lugs. By thoughtlessly
removing these tugs. you could have the I.
.27
weights fall on your foot.
12
MOUNTING WHEELS

Before Mounting Wheels

1. Free the mounting surfaces of dirt. paint.
burrs. etc.. so that there is good wheel to
hub or wheel to wheel contact. Also clean
the wheel nut ball seats.
2. Clean the stud threads and check them
for wear at the mounting face. 43
.7
3. Be sure that the end of the nut has no 4.4 1 344 te-tt
burrs. especially when tightening nuts on
aluminum wheels. The burrs could gouge
the aluminum and cause the wheel to (6.335)
crack under stress. Courtesy of Mack Truck Company

Torquing Nuts
When tire and rim problems occur. incorrect
installation and tightening practices are often
the cause.
1. Wheel nuts must be torqued:
3
(a) in the correct sequence.
(b) in several stages to the correct 4
torque specifications.
Figure 6.335 shows the torquing sequen-
ces of a five point spoke wheel and a ten
6
stud disc wheel. Note the pattern of
torquing opposite nuts in sequence.

2. In most cases wheel nuts and studs should

be clean and dry; they shouldn't be
lubricated. The exception is on aluminum
wheels and on seized or frozen nuts. /01

(6-335)
Courtesy of Mack Truck Company

528
6:234 TIRES, RIMS AND WHEELS
3. Tightening procedure:
(a) The first time around and in the
proper sequence lightly tighten nuts
with a wheel wrench so that the
wheel is seated on the hub disc
wheels. or the rim is seated on the
wheel for spoke wheels.
(b) On the second round. tighten the
nuts with a wheel wrench or air
wrench (Figure 6-336) so that the rim
or wheel is correctly positioned and
snug.
(c) Finally, tighten the nuts with a torque
wrench (Figure 6-336) to the torque
specified in the manual. Excessive
tightening can distort the wheel or
cause inconsistent brake action.
while under torquing can cause the
wheel to loosen. Avoid these
problems: use a torque wrench.
Note: On disc wheels having an inner
and outer nut these three
procedures would be gone
through twice. once for the inner
nut and once for the outer nut.

1/4

(6-336) AIR WRENCH Courtesy of Budd Company

529
TIRES, RIMS AND WHEELS 6:235

(r)

(6-336) THE TORQUE WRENCH

Couttesy of Budd Company

530
6:236 TIRES, RIMS AND WHEELS

4. As stated above the most accurate way to 6. To properly check the torque of previously
tighten wheel nuts is with a torque tightened nuts, a torque wrench should be
wrench. However. if a torque wrench is used. Apply the torque wrench on a
not available. a fairly close feet-pound ap- previously tightened nut and at the point
proximation can be achieved with a stan- the nut starts to turn read the torque in-
dard wheel wrench. Since feet-pounds of dicated on the gauge.
torque is nothing more than weight ap-
plied in pounds times distance in feet. the 7. An accurate reading cannot be obtained
mechanic weighing 180 pounds steadily on the inner cap nuts without loosening
applying his full weight three feet out on the outer cap nuts. Back off the outer cap
th9 wrench handle (Figure 6-337) until the nuts a few turns. and check the torque of
cap nut will no longer tighten will have the inner cap nuts. Then retighten the
540 feet-pounds of torque. A 200 pound outer cap nuts to the specified torque.
man applying his weight 2-1/2 feet out on
the extension would get 500 feet-pounds
of torque.
.

a
180 Pt
LBS.

AN&

, 540
LELIFT.

(.337) A BAR WRENCH

HOW TO USE A STANDARD WHEEL. WRENCH
(Assuming specified torque is 450 pound-feet)
Courtesy of Budd Company

5. If a spongy feel is obtained when the cap 8. A check should be made for tire runout (a
nuts are tightened. or if the nuts cannot be wabbfe in the wheel) after the wheel stud
pulled into a solid seat something is nuts have been torqued (Figure 6.338). AU
wrong. The assembly should be checked. wheels are susceptible to run out from im-
with wheels dismounted. for evidence of proper tightening. and spoke wheel more
worn ball seats. damaged studs or defec- so than others.
tive wheel nuts.

531
 TIRES, RIMS AND WHEELS 6:237

Rim Alignment Checks

After assembly of rims to wheels. rotate the SPACE VARIATION
wheels and check alignment. Use a block of BETWEEN EDGE OF
OUTER FLANGE
wood or other object to support marker so the WALL AND EDGE OF
marker is at the same level as the edge of the MARKER NOT TO
rim (Figure 6-338). Rotate the tire/w heel EXCEED 4en" FOR
assembly and note variations in the space be- FRONTS OR Ma" FOR
tween edge of rim and edge of marker as the REAR DUALS
assembly is rotated. Variations in excess of DO NOT GAGE TO
EDGE OF FLANGE
3132" for front assemblies or 3/16" for rear
duals indicate the rim is not properly moun-
ted.
... ...;_

To correct any misalignment, loosen nut at (6-336)

greatest variation and tighten nut on opposite Courtesy of Dayton.Watther
side. Recheck and correct until runout is
within above recommended limits.

DAMAGE AND REPAIR OF RIMS, 2 Cracks: various crack patterns are

STUDS AND HUBS shown in Figure 6-340.
Below are examples of worn or damaged rims. Cause. overloading, loose mounting.
studs. hubs. The general rule of wheel repair
is to replace weak or damaged parts. Don't at- Service: replace wheel and also nuts
tempt to straighten badly dented or distorted damaged.
wheel parts. Also. don't attempt to weld. heat.
or braze any wheel parts.
1. Worn wheel stud holes out of round
stud holes and metal build up around
outer edge of each hole (Figure 6-339).
Cause wheels working against each
other or loose nuts.
Service: replace wheels and nuts.

(6-340) CRACKED WHEELS

Courtesy of Budd Company

(6-339) WORN STUD HOLES

532
6:238 TIRES, RIMS AND WHEELS

3. Bent. damaged. rusted rims. 6. Broken studs (Figure 3-342).

Cause: overloading, hitting obstacles. Cause: loose wheel nuts. improperly
being constantly wet. seated wheels.
Service: minor dents can be hammered Service: replace stud. When a broken
out. Replace the rim if it has stud is found on a ten-hole
major damage. Similarly. minor mount, the correct practice is
corrosion should be scraped or to also replace the studs on
brushed off and the surface each side of it (Figure 6-343). In
painted with corrosion smaller hole mounts all the
resistant paint. A rim with studs would be replaced.
serious corrosion should be These extra replacements are
replaced. necessary because of the un-
due strain on the other studs
4. Damaged rings. Rings can get cracked. when one is broken.
broken, bent. corroded. Damaged rings
are a common cause of rim failure.
Cause: rough use of tire tools, im-
proper seating. hitting ob-
stacles. being constantly wet.
Service: replace rings.
Note: Before any rim or ring is reused, it
must be thoroughly cleaned. Dirt.
rust. and other foreign matter must
be removed from its surface. Pay
particular attention to seating sur-
faces and bead seat areas.

5. Stripped studs (Figure 6-341).

Causes: excess torquing of wheel nuts (6-342) BROKEN STUD
or damaging the threads when Courtesy of Budd Company
putting the wheel over the
studs.

Replace

/
ti I
(6-341) STRIPPED
Counesy of Budd Company

_ Replace
(6-343) Courtesy of Budd Company

533
 TIRES, RIMS AND WHEELS 6:239

7. Damaged inner or outer wheel nuts. SERVICE OF TRACTION DEVICES

Cause: loose mounting. Inspection
Service: replace nut and possibly the
stud. Chains
8. Seized nuts. Inspect chains for wear. damaged links,
broken c ross-links. The amount of service life
(a) Cause' corrosion or friction seizing. left in chains can be estimated by comparing
Service. lubricate first three threads of
the thickness of worn cross-links to the
thickness when new. (A link that attaches the
nuts and studs. Do not use cross-link to the side link would be relatively
penetrating oil. Be sure to keep
unworn and can be taken for new thickness.)
the lubricant off the ball seat of
the stud holes and ball face of
Broken cross-links should be repaired,
the cap nut. especially if the chains are used on a fast
moving vehicle such as a truck. A length of
(b) Cause' under torqued inner nut. cross-link flying around could damage brake
lines and Other parts around the wheels.
Service: torque inner nut to correct
pressure. Seedless Tires
9. Broken, cracked or worn hub face (Figure When inspecting a beadles tire check:
6-344).
1. the side walls of the carcass for cuts.
Cause: loose wheel assembly. damage.
Service: superficial face wear can be 2. the mounting belt for damage.
repaired by machining the sur-
face flat. A hub with ':racks or 3. the track shoes for looseness. Also check
breaks must be replaced. for worn cracked. damaged. missing
shoes.
The height of the grouser bars should also be
measured and when worn below a certain
limit (see service manual) they should be
replaced.

installing Chains
Skid chains may be installed in one of two
ways. In a shop. jack or lift the vehicle so it
clears the ground. Then place the chain over
the top of the tire and latch the ends of the
side links together at the bottom. The chain
cross-links must then be positioned around
the lugs of the tire so that they lay as straight
(6-344) as possible across the face of the tire.
Courtesy *1 Mack Truck Company Retighten the couplers so that the chain is
snug but not too tight. A word of advice: put-
ting on chains is more difficult than it sounds.
especially on large wheels.
To put on chains on the road. lay the chain out
flat in front or rear of the tire and run the tire
onto the chain a foot or two from the end. The
other end of the chain is then dragged over
the top of the tire so the two ends can be
coupled together. Chains are heavy and often
there are obstructions like fenders that make
it difficult to work the cross-links around so
they lay straight enabling the side links to be

534
 6:240 TIRES, RIMS AND WHEELS

snugged up. A bar will often help in working Protection chains. due to their weight, are
the chain into position. Once the chain is more difficult to install than traction chains.
coupled. moving the vehicle back and forth Figure 6.346 shows how the chains can be in-
will aid in positioning the chain and will take stalled by hooking one t,nd to a small chain
out the slack. To help tighten chains. chain tied part way around the tire. The machine is
tighteners can be made from strips of old in then backed up to drape the chain around the
ner labs. with hooks on each end. On each tire. Final hooking is done with the aid of the
cha.n two tighteners are attached to the side loader's hydraulics. in a shop, these protec-
links in a diagonal (Figure 6-345). tion chains can be installed by jacking up the
machine and lifting the chains onto the tire
with a hoist. The method above. though, is
probably the easiest.

RUBBER TIGI-ITENERS

(6-345)
Courtesy Dominion Chain Co

(6-346)
maw
Air 411111. I. :. -.4-

_Irs.te-froifisissian

ve

"11
=
ree
;: .

535
 TIRES, RIMS AND WHEELS 6:241

QUESTION"' TIRES, RIMS, WHEELS 11. Wheel and tire runout can be caused by:
MAINTENANCE AND REPAIR
(a) improperly adjusted wheel bearings.
1. Low tire pressure causes:
(b) a bent wheel.
(a) increased tire contact with the road.
(c) an improperly tightened wheel.
(0 increased rolling resistance.
(d) a faulty tire.
(c) increased tire heat due to flexing.
(e) all of the above can cause runout.
(d) only (a) and (c) are correct.
12. What is the general rule of repair for
(e) (a). (b) and (c) are all correct. worn or damaged rims, studs. nuts and
hubs?
2. When is the best time to take tire
pressure? 13. If one stud breaks on a ten stud disc
wheel. the accepted practice is to:
3. What is rapid heat build-up in ileavy
equipment off-the-road tires caused by? (a) replace all the studs.
4 When inflating a tire. what precautions (b) replace the broken stud and the two
must be taken? studs on either side of it.
5 When matching tires on a tandem truck. (c) replace the broken stud and the
the allowable difference in tire cir- stud 180° opposite it.
cumferences is:
(d) change at least five studs.
1/4"
14. True or False? When installing wheel
3/4" nuts, they should be clean and dry, and
not lubricated.
2-1 /2"
1-1/2"
15. How do you check the torque of a
previously tightened nut?
6 True or False/ A recapped or 16. Why should broken cross-links on chains
regrooved tire should not be used on the be fixed immediately?
front of a vehicle.
7. What is the minimum depth of tread
allowed by safety standards for front
tires?
8. When installing wheels, the nuts should
be tightened in a:
(a) circular pattern clockwise.
(b) circular pattern anti-clockwise.
(c) crisscross pattern. tightening op-
posite nuts on sequence.
(d) Any of the above.
9. A wrench is recommended
for final tightening wheel nuts.
10. When removing rims and tires from dual
cast spoke wheels what .: a good prac-
tice to follow before removing the lug
nuts?

536
6:242 TIRES, RIMS AND WHEELS

ANSWERS TIRES, RIMS AND WHEELS, 14. ... slippage ....

BALLAST, TRACTION DEVICES
15. (c) filling the tires with liquid or dry
1. Support the machine. ballast.
Give traction. 16. (b) 75% calcium chloride. 25% air.
Provide flotation.
17. Use adequate lifting equipment.
Absorb or cushion shocks.
Provide a replaceable wear surface.
18. ... traction.... protection.
19. A beadless tire carcass has a belt around
2. Over-the-road tires; off-the-road tires. the circumference to which steel shoes
Tube. tubeless. are attached.
3. H Load range.
R Radial ply.
78 Height to width ration.
15 Rim size.
4. The tire bead:
is the base to which all the tire plies
are tied.
anchors the tire to the rim besides
maintaining the shape and fit of the
tire on the rim.
5. True.
6. Less damaging heat build-up.
7. (a) downward as viewed from the front.
8. False.
9. Load size and vehicle speed.
10. The cast spoke wheel and rim are two
separate parts. whereas the disc wheel
and rim are one.
11. The rim (or rims on dual wheels) for a
cast spoke wheel is retained by lugs and
nuts. Disc wheels. on the other hand. are
retained by ball seat cap nuts which are
threaded to studs in the hub. Dual disc
wheels have an inner and outer nut
arrangement.
12. There are two sets of nuts: nuts holding
the split wheel together and nuts holding
the wheel to the hub. Know which is
which. Removing the split wheel nuts
thinking they are the hub nuts could
cause serious injury. To play it safe.
deflate the tire befora removing the
wheel.
13. They are stamped with an "R" or "L" or
with the words Left or Right. Left hand
thread nuts can also be nicked at the
corners in a circular pattern around the
nut.

537
 TIRES, RIMS AND WHEELS 6:243

ANSWERS TIRES, RIMS, WHEELS

MAINTENANCE AND REPAIR
1. (e) (a). (b) and (c) are all correct.
2. After the tires have had a chance to cool
down. If pressure is taken when the tires
are hot. the reading will be higher than it
actually is.
3. Excessive speed. over-loading, and un-
der-inflation.
4. (1) Make sure the lock ring is properly
seated before inflating.
(2) Use an inflating cage or a press
when inflating the tire. or use a self-
attaching air chuck and stand to
one side.
5. (d) 1-1/2"
6. True.
7. 1/8".
8. (c) Crisscross pattern, tightening op-
posite nuts in sequence.
9. .. . torque ....
10. Loosen the nuts and tap the lugs with a
hammer to ensure that the lugs are loose
before removing the nut.
11. (e) all of the above can cause runout.
12. Replace any damaged. weak or worn
parts.
13. (b) Replace the broken stud and the
two studs on either side of it.
14. True.
15. Apply a torque wrench to the nut. and
when the nut starts to turn, note the
torque reading.
16. The cross-link flying around could
damage brake lines and other parts
around the wheel.

538
6:244 TIRES, RIMS AND WHEELS

TASKS TIRES, RIMS AND WHEELS, (b) Practice safety when

TRACTION DEVICES removing split rim wheels.
Make sure you remove the
DAILY, ROUTINE MAINTENANCE hub bolts and not the split
CHECKS rim retaining bolts (see
manual to distinguish). If
1. On a wheel vehicle commonly found in in doubt deflate the tire
your shop. check tire pressures. and also before removing it.
check the tires for wear. cuts. or damage.
Change or report unsafe tires. 3. If chains are available. inspect them for
wear. cracked or broken links or missing
SCHEDULED MAINTENANCE sections. Make any needed repairs. If a
Caterpillar loader with beadless tires is
1. Match the tires on the rear wheels of a available, inspect the tires for severely
tandem drive truck: worn. cracked. broken or missing shoes.
(a) Measure the rolling circumference of Also check to see that the shoes are tight.
all tires on the drive axles. Replace any shoes that are not ser-
viceable. Chick the carcass if it has to be
(b) Match the tires in sets of two so that replaced completely deflate it before
the circumferences of both tires are removing the rim half bolts.
within 1-1/2 inches.
(c) Rearrange the tires on the vehicle.
putting the matched tires together.
Install and position the wheels
tightening the wheel nuts in the
proper sequence to the correct
torque.

SERVICE REPAIR
1. Inspect the rims on a wheeled vehicle for
cracks. bends. or other damage. Check
the condition of the locking ring. Check
for worn or damaged studs. bolts, moun-
ting holes, retaining lugs. Make any
necessary repairs or replacements or
report damage that makes the vehicle un-
safe to operate.

2. Using the correct tools. lifting equipment.

and procedures. remove demountable
rims and tires from a vehicle with single
and dual mountings. Do the same with a
vehicle that has disc rims. Also install and
position the wheels. tightening the wheel
nuts in the proper sequence and to the
correct torque. Note that part of this task
will have been done in task 1 (c).
Caution: (a) Because ballast weighted
wheels (either internal or
external ballast) are very
heavy. practice safety
when removing and in-
stalling them.

539
 WHEEL MACHINE FINAL DRIVES 6:245
FROM
PURPOSE OF WHEEL FINAL DRIVES DIFFERENTIAL PINION
GEAR
The purpose of final drives on wheel
machines is similar to those on track
machines: to decrease speed to the drive
wheels while simultaneously increasing wheel
torque or turning power. There are three main AXLE
types of wheel final drives:
TO
single reduction spur gear AXLE WHEEL
o
Ar
SHAFT
sprocket and chain
planetary (inboard and outboard)
/ -10
SINGLE REDUCTION SPUR GEAR
FINAL DRIVE
Single reduction spur gear final drives are FINAL DRIVE
(6-347) SPUR GEAR
mainly used on farm tractor& although they
SINGLE REDUCTION SPUR GEAR
are also used on some graders and on some FINAL DRIVE
large off-highway rear dump trucks. Spur gear X 2 287
Courtesy of John Deere Ltd
final drives operate on the basic gear prin-
ciple that when a small gear drives a large Final drive housings serve as the oil reservoir
gear. the RPM's of the large gear decreases for the assembly maintaining oil at a level that
while its torque or turning power increases. supports a splash lubrication system for the
Power is supplied by the axle shaft to the gears and bearings. The housing may be
drive pinion gear which meshes with the large separate from. or part of. the main trans-
final drive gear. Both gears are supported by mission and differential case. An example of a
bearings: a short axle shaft that may be part housing assembly is shown in Figure 6-348. It
of. or spfined to. the final drive gear transmits has single reduction final drives located in
power to the wheel (Figure 6.347). housings on either side of the bevel gear com-
partment.
BEVEL
DRIVE PINION
FINAL DRIVE GEAR
PINION DRIVE PINION BEARING
SUPPORT BEARING

AXLE SHAFT
FINAL DRIVE GEAR
CIRCULAR FLANGE (6-348)
Courtesy 0 Champion Road Machinery Limited

541
6:246 WHEEL MACHINE FINAL DRIVES

Note in Figure 6-348 that the final drive

pinions are attached to the bevel gear shaft
and that the large final drive gears are sup-
ported by bearings in the housings attached
to the bevel gear compartment. Also note the
circular flange at the outer ends of the final
drive housings: this is where the tandem
wheel housing assemblies, described earlier
in the section on grader 3uspension. are
bolted. A double sprocket (Figure 6-349) is
splines to the final drive axle shaft which ex-
tends into the tande housings. Power is sent
from the sprockets to each wheel via separate
drive chains. The tandem housing oscillates.
having the final drive circular flange as its
pivo point
DRIVE AXLE

FINAL DRIVE
SPROCKETS (2)

WHEEL
SPINDLE WHEEL
SPINDLE
SPROCKET

DRIVE CHAIN

(6-349)
Courtesy of Champion Road Machinery Limded

SPROCKET AND CHAIN FINAL DRIVES PLANETARY FINAL DRIVES

While discussing this tandem wheel assembly, Planetary final drives are probably the most
it's appropriate to mention another type of common type of final drive used on heavy duty
final drive: the sprocket and chain. Just as dif- wheel equipment today. A few examples of
ferent size gears can alter speed/torque retie, machines using planetary final drives are:
so can different size sprockets. If the two loaders, skidders. scrapers. cranes, graders,
sprockets on the final drive axle are the same and off-highway trucks.
size as the sprockets for the wheel spindle,
then there is a one to one ratio and no speed Planetaries have the advantages of (a)
reduction occurs. If, however. there is a small providing a high reduction within a compact
sprocket at the drive axle and a larger space and (b) being strong because the load
sprocket at the wheel spindle, then a reduc- is spread over more than one gear. The
tion will occur: power train speed will be operation of planetaries was described in
reduced and its torque increased. Block 5 Power Trains. Review this section.
Planetary final drives for wheel machines may
The tandem wheel assembly is partially filled be mounted inboard. next to the differential. or
with oil so that the chain and sprockets run in outboard. next to the wheel (Figures 6-350 and
an oil bath. 6-351).

542
 WHEEL MACHINE FINAL DRIVES 6:247

INBOARD
PLANETARY
Courtesy of Jain Deere Lid
r
A Li _0". 47®,
(6 -351) CoaftesY of Caterpillar Tractor Co
Outboard planetaries are the most common
type of wheel final drive used today. a main
reason being that they are conveniently
located for servicing. Most of the necessary
service on these planetaries can be performed
without jacking up the unit or removing the
OUTBOARD PLANETARY
fires. The outboard position also gives the
torque increase at the wheel and so the axle
Inboard planetaries are used mainly for farm shaft doesn't have to carry the increased
tractors. although Caterpillar uses one on torque. The housings for outboard planetaries
their grader. Some large electric drive mine are incorporated within the wheel-hub assem-
trucks also use inboard planetaries. bly and are mounted on the outer ends of the
rigid axle housing (which includes the dif-
ferential and axle housings) (Figure 6-352).
4

DIFFERENTIAL

(6-352)
FINAL DRIVE HOUSING
Courtesy of Rockwell Internahonal
Automotive Opera lions As you recall from the introduction to
planetaries in Block 5, Power Trains, there are
various possible combinations of the three
SUN OR planetary gears (the ring. sun, and planet
CENTER GEAR carrier) each of which will give a different
torque/speed ratio and direction of power
flow. The combination used for wheel
planetaries is (Figure 6-353):

AXLE
SHAFT
PLANET
CARRIER
GEARS (6-353) RING OR
INTERNAL GEAR

543
6:248 WHEEL MACHINE FINAL DRIVES

1. The ring gear is held. Usually it is splined RING GEAR

or attached to the stationary housing.
2. The sun gear. splined to the axle shaft. is
powered.
3. The carrier is driven by the sun around the
inside of the stationary ring gear. Since
the carrier is attached to the wheel hub.
the hub and wheel assembly are driven at
a reduction. Figure 6-354 shows how the
carrier is attached to the hub: the ends of
the planet gear shafts fit into bosses in the
hub cover which is bolted to the hub.
Therefore when the carrier turns, the hub
is forced to turn. Notice in this planetary
final drive how all the gears fit inside one
another and hence the reason for its com-
pactness.
WHEEL SUN GEAR
The above planetary transmits power from the HUB
planet carrier to the wheel hub. When ---.... s PLANET PINIONS
planetaries are used on a grader. the carrier is
PLANET PINION SHAFTS FITTING
attached to a shaft that is connected at its IN BOSSES IN THE HUB COVER
other end to the drive sprockets in the tandem
wheel assembly (Figure 6-355). (6-354)
Courtesy Of John Deere Ltd
Outboard final drives are lubricated by splash.
Some wheel final drives have an oil fill plug
on the outer cover which is also the oil level
plug: oil is filled through this hole until it
begins to flow out. Other wheel final drives
have a fill plug on the outer housing and a
separate level plug on the cover. Inboard
planetaries are usually splash lubricated by
oil from the bevel gear compartment. 1

n 110111111

FINAL AND TANDEM DRIVES

1Shalt. 2Sun gear. 3Carrier. 4Outer shaft. 5Drive sprockets. 6Drive chain.
7Onve chain. 8Oriven sprocket. 9 Driven sprocket. 10Planet gear. 11Ring gear.
12 Housing. 13Ring. 14-110uSing. 15Thrust washers. 16Wheel spindle.
Courtesy of Caterpillar tractor Co

544
 WHEEL MACHINE FINAL DRIVES 6:249

A cutaway view of an outboard planetary Is

shown in Figure 6-356. Note that the ring gear
i2) is held by a spline on the outer end of the
spindle (22). The lock nut assembly (7) holds
the ring gear in place and provides the means
of adjusting the wheel bearings (14). The
planetary cover (4), part of the carrier. trans-
mits the drive to the wheels. The axle shaft
(23) is lull floating; it transmits power and
does not carry any of the vehicle's weight. The
spindles support the weight, as it does in all
outboard planetary wheel final drives.

12

Io
14 14 15
tt

1---L ;571-7-1F-6"(11
el ---
19
. 28 21
1..))

L.

I Driver 8 Pint On Pm 15 Brake Drum 22 Spindle

2 Rong Gear 9 Planet Pinion 16 Brake Shoe Assembly 23 Axle snarl
3 Retainer Ring 10 "0" Ring 17 Cam 24 Seal Bushing
4 Planetary Cover 11 Lock Ring 18 Cam Shaft 25 Grease C-eru
5 Sun Gear 12 Flange 19 Snap Ring 26 Anchor Pin
6 Spacer Ring 13 Bead Seat 20 Seal 27 Rim
7 Locknul Assembly 14 Bearing Assembly 17" Flutter Washer 2e Wheel
26 Valve Assembly
(6-356)
Courtesy 01 Tetex General Motors Corporation

545
6:250 WHEEL MACHINE FINAL DRIVES

Towing Precautions Involving The Axle and SCHEDULED MAINTENANCE

Planetary
Scheduled Maintenance for wheel final drives
If a vehicle having wheel final drives is to be includes:
towed, due to a breakdown for example, the
axle shaft and sun gear should be removed 1. draining the housing
from each planetary assembly (Figure 6-357). 2. checking for accumulation of metal chips
Removing them will prevent possible damage
to the power train components during towing. 3. refilling with the correct type and amount
The axle shafts and sun gears can be of oil
removed easily by taking off the driving flange
cover and simply sliding the axle shaft, 4. checking for leaks when complete.
together with the sun gear. out of each The hour interval for the oil change varies
planetary assembly. Pour a small amount of with the manufacturer, anywhere from 1000 to
oil in, and replace the driving flange covers to 2000 hours. This interval will be shorter if the
protect the planetary assemblies from road machine is working in a lot of water or in
dust and dirt. heavy rain. Note that vehicles having out-
board planetaries, final drives and wheel
brakes will have the planetary oil changed
every time the brakes are serviced because
the brakes can only be reached by
disassembling the final drive. Brakes will
usually be serviced at 1000 to 1500 hour in-
tervals, although this interval will depend on
the severity of the work the machine is per-
forming.
Final Drives should give many miles or hours
of trouble-free service providing (1) the seals
`, 7 are replaced when work is done on the
assembly. (2) the bearings are adjusted
(6-357) correctly, and (3) the oil is maintained at the
Courtesy or Caterpular Tractor CO correct level. However, final drives are subject
to damage by shock loading, frequent direc-
MAINTENANCE AND SERV'CE REPAIR OF tion change. and over loading.
WHEEL MACHINE FINAL DRIVES
SERVICE REPAIR OF WHEEL
PREVENTIVE MAINTENANCE FINAL DRIVES

DAILY, ROUTINE MAINTENANCE Indications that final drives need repair are:
CHECKS 1. Accumulation of metal chips found in the
A visual inspection of th final drives should final drive oil when changing it.
be included as part of tie daily walk around 2. A leaking final drive that requires frequent
check. The inspection involves checking for topping up.
oil leaks and periodically (approximately
every 250 hours) checking the oil level. Note 3. UnusP.al noises in the wheel assembly.
that outboard planetaries and grader chain Not heec.ing these warning signs could lead
and sprocket tandem wheel assemblies have to complete failure of the unit.
their own oil supplies, whereas inboard
planetaries and spur gear final drives usually Procedures required to gain access to the dif-
share a common oil reservoir with the dif- ferent types of final drives single reduction
ferential. Always maintain final drives at the spur gear. sprocket and chain, and planetary
correct oil level; if the oil is down, overheating vary, but there are some similarities such
will occur and the gear will be damaged. as cleaning the assembly. draining its oil and
removing wheels. Outboard planetaries are
the most common type of wheel final drive,
and so points about its removal and repair are
given below:

546
 WHEEL MACHINE FINAL DRIVES 6:251

1. Always clean the housing area where the

work is to be done. Use a steam cleaner or
a high pressure washer. If this equipment
is not available. wash by hand.
2. In.preparing to remove planetaries. block
and jack the machine so that the tires just
clear the floor. If the machine has ar-
ticulated steering install the steering
safety rod.
3 Although planetaries may be disassem- 1=k":
:

bled without taking off the wheels. it is 2.77-1.1,

usually much more convenient to do so.

Follow safety practices for removing
wheels discussed earlier.

4. When draining the oil. removal of the level (6-358)

plug (if applicable) will vent the final drive USING A HEAVY WIRE HOOK. PULL AXLE
and thus aid in the draining. SHAFT AND SUN GEAR OUT OF WHEEL END
Courtesy of Clarke Equipment Company
5. Disassembly of the planetary is fairly
straight forward. If the hub is not going to
be removed, support it with a sling and
overhead crane or a floor jack. it is a good
practice to remove the hub, though, so
that the bearings can be cleaned, in-
spected, repacked and the seal replaced.
Figure 6-358 shows some of the dismantl-
ing procedures of a typical outboard
planetary.

22.011MMINr.-

(6 -358)-
USING THREADED BOLTS IN THE PULL HOLES
PROVIDED, EVENLY REMOVE PLANET CARRIER
ASSEMBLY. USE CAUTION AS NOT TO RUN
CARRIER OFF STUDS BEFORE A CHAIN SUP-
PORT IS USED
ceunesy of Clarke Equipment Company
6. Once disassembled, all final drive parts
such as gear teeth, shafts, thrust washers.
splines should be cleaned and inspected
for wear and damage. (Refer to the sec-
(6-358) REMOVE PLANET COVER tion on types of gear wear in Crawler Final
CounesY of Clarke Equipment Company Drives.) Replace all badly worn or
damaged parts saving the old parts for
comparison with the new before installing
the new ones.

1'4?
Good Installation Practices For Final Drives
1. Pre-lub all gear shafts and thrust washers.
2. Replace all gaskets and 0-rings.

547
6:252 WHEEL MACHINE FINAL DRIVES

3. Use the correct tool for installing seals.

When installing a new lip-type oil seal.
make sure it is flexible or pliable in the
area where the seal fits around the shaft.
Also. lubricate the lip before installing the
hub.
4. Follow from the service manual the
correct procedures for preloading the
bearings. A common example of
preloading the wheel bearings (new and
used) on a machine having an outboard
planetary is given below:
(a) Lubricate both bearings wit" gear oil
or grease as specified in the service
manual.
./
(b) White turning the planetary housing.
tighten the wheel bearing nut to 400 (6.359) CHECKING BEARING PRELOAD WITH
feet-pounds. Turn the planetary PULL SCALE
housing in both directions to coirec- Courtesy of John Deere 1.1d.
fly seat the wheel bearings.
Note that in this example the preload is
(c) Loosen the wheel bearing nut one given in straight pounds pull. Often the
quarter turn. preload will be given in inch-pounds
which is found by multiplying the radius
(d) Connect at least ten feet of cord to a
(distance from the center of the drive shaft
pound pull scale. Connect the loose
end of the cord to one of the wheel
to a point on the circumference from
nut studs and wrap the cord around which the cord is pulled, (Figure 6-359) by
the planetary housing as illustrated the reading on die pound scale. For exam-
in Figure 6-359. ple: Assume the radius is 7 inches and the
reading on the scale is 9 pounds. Multiply
(e) Pull the scale on a horizontal line by 7 inches by 9 pounds and to get 63 inches-
backing away from the machine. pounds of rolling torque.
Read the scale as the planetary Preload can also be given in feet-pounds.
housing is turning. The scale in-
To change the 63 inchespounds from the
dication must be 9 to 13 pounds. Do
example to feet-pounds simply divide the
this step two more times to get an ac- 63 by 12 to get 5.25 feet-pounds of
curate indication of the force needed preload.
to turn the planetary housing. DO
NOT read the scale as the planetary Another method of checking 'nearing
housing starts to turn. If the force preload is to use a torque wrench with a
needed to keep the planetary special tool or adapter (Figure 6 -360) The
housing turning is not 9 to 13 pounds. adapter can be easily made up. This
tighten or loosen the wheel bearing method gives a direct reading on the
nut accordingly and test again. wrench.
.---"..°1
2

(6-360)
1Brake drum. 2Wheel. 3Special tool.
4Ring gear. 5Torque wrench. 6Locknut
Courtesy of Terex. General Motors Corporation

548
 WHEEL MACHINE FINAL DRIVES 6:253

Adjusting Axle End play 5. Attach an over head crane or similar type
of lifting equipment to the housing.
Some types of drive assemblies call for a Remove the housing attaching bolts and
slight amount of end play. This means that the lift the housing clear of the machine. Note
shaft, when properly adjusted. must be free to that the center drive sprocket may have to
move endways within the limits specified. The
be removed before the housing can be
end movement in most cases is between 0.001
and 0.010 inches. To obtain the proper end
r red and the brake lines discon-
nected.
play. shims or an adjusting nut are provided.
Measure the end play with a dial indicator. As 6. Disassemble the spindles. Clean and in-
shown in Figure 6-361: this is a single spect the sprockets. drive chains. splines.
reduction final drive assembly for a small bearings and seals for damage and wear.
wheel tractor. Make a list of the parts required.
7. Reassemble the tandem in the reverse or-
der, following recommended torques and
adjustments given in the service manual.
8. Refill the housing with the correct type
and amount of oil. Check for leaks.

Removing The Final Drives

To remove a final drive once the tandem
housing is off may require. on some machines,
removing the complete differential assembly.
However, on other machines the final drives
are accessible from the outside as is shown in
Figure 6-362. Here the final drive is being
rolled from the machine on a wheel Jack.
Disassemble the final drive and clean and in-
(6-361) spect the parts. replacing any that are worn or
FINAL DRIVES r$711 damaged.
CHECKING FINAL DRIVE SHAFT END PLAY
WITH A DIAL INDICATOR
Courtesy of John Deere Ltd

Removing and Installing Grader Tandem

Housings
The procedures for removing and installing
tandem housings vary f re- ',le grader to
another (see service rm... for specific
procedures). but there are some steps That are
common to most graders: 14

1. Thorougl.'y clean the tandem housings.

including the wheel spindles and A 5X1
Atiew
oscillaticn or pivot point. before starting (6-362)
disassembly. The cleaning, due to the size Courtesy of Caterpillar Tractor Co
of the Job. is time consuming to do by
hand. and should be done with a steam
cleaner or high pressure washer.
2. and block the machine so that the
e free of the floor. Then remove
the eels.
.he oil from the housing.
4. Remove the drive chains.

549
6:254 WHEEL MACHINE FINAL DRIVES

QUESTIONS WHEEL FINAL DRIVES 12. To check the preload on wheel bearings
using the spring scale method:
1. Wheel final drives:
(a) multiply the pounds pull on the
(a) decrease speed and increase scale times the circumference of the
torque. hub.
(b) increase speed and decrease (b) multiply the pounds pull times the
torque. diameter of the hub.
(c) decrease speed an decrease (c) multiply the pounds pull times the
torque. radius of the hub.
(d) increase speed and increase torque. (d) multiply the pounds pull times the
2. List the three major types of final drives number of wraps of cord around the
used on wheel equipment. hub.

3. What is the advantage of having the final 13. True or False? Some graders have two
drive out at the wheel assembly rather final drive reductions: one before the
than next to the differential? tandem housing and one within the tan-
dem housing.
4. How can the sprockets and chains in a 14. Does the drive sprocket in a tandem
grader tandem housing give a reduction? housing have to be taken off before the
5. What is the most common type of final housing can be removed?
drive used on wheel machines? Give at
least two examples of machines using
these final drives.

6. On a planetary wheel final drive. how

does the carrier gear transmit power to
the hub?
7. Wheel final drives are lubricated by:
(a) pressure feed.
(b) splash feed.
(c) combination of splash and pressure
feed.
(d) prelubricating all the parts with
grease on assembly.
8. If a machine equipped with planetary
wheel final drives has to be towed:
(a) the planet carrier should be
removed.
(b) the sun gear should be removed.
(c) the sun gear and axle shaft should
be removed. and the cover replaced.
(d) the ring gear should be removed.
9. Final drives are subject to damage by
what three common causes?
10. List three signs that would indicate
wheel final drives need repair.
11. True or False? The complete wheel and
hub assembly must be removed to
disassemble a planetary final drive.

550
 WHEEL MACHINE FINAL DRIVES 6:255

ANSWERS WHEEL FINAL DRIVES

1. (a) decrease speed and increase
torque.
2. Single reduction spur gear.
Planetary.
Sprocket and chain.
3. Outboard final drives are:
conventiently located for servicing.
positioned so that the drive axle shaft
doesn't have to carry the increased
torque.
4. If the wheel spindle sprocket is larger
than the drive sprocket, a reduction is
achieved.
5. Planetary final drives: loaders, skidders.
scrapers.
6. The ends of the shafts for the carrier
planet pinion gears fit into bosses in the
hub cover causing the hub to turn.
7. (b) Splash feed.
8. (c) The sun gear and axle shaft should
be removed and the cover replaced.
9. Shock-loading.
Frequent direction changes.
Overloading.
10. Accumulation of metal chips in the
final drive oil.
Leaks requiring frequent topping up
of final drive oil.
Unusual noises in the assembly.
11. False.
12 (c) Multiply the pounds pull times the
radius of the hub.
13. True.

14. On some machines. but not on others

55i
6:256 WHEEL MACHINE FINAL DRIVES

TASKS WHEEL MACHINE

FINAL DRIVES

DAILY, ROUTINE MAINTENANCE

CHECK
Check a wheel machine's final drives for
leaks a, seals and gasket joints and for any
other visible damage. Report any major ser-
vice repair needed.

SCHEDULED MAINTENANCE CHECK

Scheduled maintenance procedures from the
service manual for a wheel machine's final
drives include:
1. Drain the housing, inspect the oil for
metal chips and signs of moisture. Report
any chips or moisture detected and make
recommendations for needed repairs.
2. Replace the drain plug and refill the
housing with the correct type and amount
of lubricant.

SERVICE REPAIR
1. Using the correct jacking and blocking
procedures (on articulated machines in-
stall the steering safety rod), raise a wheel Cr,
machine with final drives and block it
securely at a height that allows the wheel
and final drive assembly to be safely
removed.
2. Using the correct tools, lifting equipment
and procedures outlined in the service
manual:
'a) drain the final drive housing.
(b) remove the wheel and steam clean
the final drive assembly.
(c) disassemble, inspect the gears.
bearings. seals (sprockets and
chains if grader). Write a parts list.
Make the necessary repairs and
replacements.
(d) pre lubricate the final drive parts,
reassemble and adjust the bearings.
(e) install the wheel. tightening the nuts
in the correct sequence.
(f) fill the drive line housing with the
correct type and amount of oil, and
ensure there are no leaks.

552
 BLOCK

Wheel Machine Steering

and Front Suspension

653
 WHEEL MACHINE STEERING AND FRONT SUSPENSION G:257

STEERING PRINCIPLES KING PIN

Not all wheel vehicles use their front wheels
for turning, e.g., some loaders have back
wheels that turn. Other machines such as
skidders, scrapers, wheel dozers and loaders
have articulated steering. Although there are
differences in the way that wheel machines
are steered, they do share some common
steering principles.

HOW WHEELS TURN (6.364)

Courtesy of Caterpillar Tractor Co.
To illustrate how wheels turn, a basic manual
steering system is described below. CONTROL ARM
The steering wheel is attached to the end of
the steering column or shaft. At the lower end
of the shaft is a worm gear that rotates as the
steering wheel is turned (Figure 6-363). The
worm gear meshes with a sector gear which is
shaped like a slice of pie. The sector gear
need not be circular because it only rotates a
few degrees (approximately 30°) in each
direction. The sector gear has a lower ex- (6-365)
tension called a steering arm. This arm is Courtesy of Caterpillar Tractor Co.
sometimes referred to as a Pitman arm (Figure
6-363). The steering part that connects the wheels to
WORM GEAR
the steering box is called a drag link (Figure
6-366). The drag link is attached at one end to
the wheel control arm and at the other to the
Pitman arm. Movement of the steering wheel
can now be transferred to the wheel.
STEERING One more part is needed to complete the
COLUMN steering system. The steering mechanisms, as
shown, are connected to only one wheel. the
left front. Some method is needed to syn-
chronize its movement with that of the right
PITMAN ARM SECTOR GEAR front wheel. A tie rod (or cross tube) does this.
(6-363) It is connected to an extension of the control
Courtesy of Caterpillar Tractor Co. arm and travels across to an arm on the other
wheel (Figure 6-367). When the left wheel is
Looking at these steering parts in operation, turned, the tie rod makes the right wheel
the steering wheel turns the steering column follow. A completed basic manual steering
and worm gear. The worm gear moves the system is shown in Figure 6-368.
sector gear, which pivots at the center,
causing the steering arm to move back and CONTROL ARM
forth. Thus rotary motion at the steering wheel
is transformed into linear motion at the
steering arm.
Move now from the ',tiering box section of the oR
steering system to the wheels. The front
wheels are attached to the axle by a pivot pin
(king pin) that acts as a hinge allowing each
wheel to turn (Figure 6-364). To control wheel
movement, a short arm, called a steering con- DRAG LINK
trol arm, is attached to the wheel (Figure 6- (6-366)
365). When the steering arm is moved the Coo nosy of Caterpillar Tractor Co.
wheel turns.

554
 6:258 WHEEL MACHINE STEERING AND FRONT SUSPENSION

MANUAL. STEERING SYSTEMS

A basic manual steering system has been
described above in the section on how wheels
turn. The material here takes a closer look at
the following manual steering parts.
Manual Steering Gears
worm and roller
TIE ROO recirculating ba!I
(6-367)
cam and lever
Courtesy 01 Caterpillar Tractor Co
Front Axles and Suspension
A point to note about this steering system is
that the worm gear can turn the sector gear, spring hanger brackets
but the sector can't turn the worm. This one shackles, pins, bushings
way relationship is made possible by the gear
reduction between the worm and the sector. It springs. U-bolts
is an important feature, because otherwise, if shock absorbers
a wheel struck a curb or a stone, a reverse steering axle
steering would be set in motion that could jerk
the steering wheel from the driver's hands. king pins
STEERING GEAR ASSEMBLY
steering knuckle and bushings
PITMAN ARM Steering linkage
RAG LINK steering spindle arms
INTERMEDIATE ARM tie rods, tie rod ends
Grader Steering Parts
STEERING ARM MANUAL STEERING GEARS
TIE ROO
The function of manual steering gears is to:
1. Change the rotary motion at the steering
wheel to linen movement at the tie rod to
steer the wheels.
2. Steer a vehicle with a minimum of effort. A
small force at the steering wheel must
STEERING turn a heavy mass at the front axle. This
ARM
advantage is gained by the gear ratios in
the steering box which can range from
(6-368) SOLID AXLE STEERING LINKAGE about 12:1 to 28:1, and even higher.
Courtesy of Ford Motor Company
3. Dissipate road shock. The mechanical ad-
vantage of the high gear ratio helps
TYPES OF WHEEL STEERING SYSTEMS cushion shocks.
1. Manual Steering There are three types of manual steering
2. Power Steering gears currently found in the heavy duty field:
power-assist worm and roller
full power recirculating ball
hydrostatic cam and lever
3. Emergency steering Another manual gear. the worm and sector.
was used in the past but is seldom seen today.

555
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:259

Worm and Roller Gear

This steering gear consists of an hourglass-
shaped worm gear meshed with an offset,
three-tooth roller gear. The roller gear is part
of a roller shaft (figure 6-369).
The worm gear is supported by tapered roller
bearings; one bearing cup is pressed into the
steering gear housing, while the other cup is
slip fitted to permit the bearings to be
preloaded. The preload adjustment is made by
a shim pack located between the steering
gear housing and the worm cover. The roller
shaft is supported by needle bearings. Roller
shaft end play is regulated by an adjusting
screw threaded into the roller shaft cover.
The worm and roller gear operates as follows:
the worm is connected to the steering wheel
through either a coupling just outside the
steering gear box or by a continuous shaft
that goes directly to the wheel: The roller
shaft is splined to the Pitman arm. When the
steering wheel is rotated, the worm gear
"rolls" the roller gear causing the roller shaft
to rotate. The roller shaft, in turn, sets the Pit-
man arm and steering linkage in motion to
steer the vehicle.
Worm and roller manual steering gears are
used in a wide variety of vehicles from trucks
and buses to industrial machines. The same
basic design has been used for many years.
The gear is simple, yet strong, and gives a
fairly low-friction operation.

WORM HOUSING
COVER
FILLER PLUG
WORM COVER
SHIM PACK TUBE

WORM

ROLLER SHAFT

ROLLER, '
ADJUSTING SCREW

ADJUSTING SCREW
=KNOT

DRAIN PLUG
(6-369) Courtesy of Mack Truck Limited
WORM AND ROLLER GEAR

556
6:260 WHEEL MACHINE STEERING AND FRONT SUSPE%SION
Recirculating Ball Steering Gear Provision is made to externally adjust the
A recirculating ball steering gear: worm shaft bearings and the sector shaft. The
worm shaft (1) is mounted between two
1. Uses a straight worm as opposed to the tapered roller bearings (10. 16). Preload on
hourglass-shaped worm of the worm and these bearings is adjusted by means of a
roller steering gear. thrust bearing adjuster (2) which is threaded
2. Has a bail nut that is supported on the into the steering gear housing (4). The sector
worm by a number of steel balls that act shaft (28) is mounted in bushings in the gear
as bearings, minimizing friction between housing and the side cover (20). Lash between
the ball nut and worm. During movement the sector gear and ball nut is controlled by a
of the ball nut on the worm the steel balls lash adjuster (21), located in the side cover.
continuously recirculate from one end of End play of the sector shaft is controlled by a
the nut to the other through a ball return shim (23) under the head of the lash adjuster.
guide (9, in Figure 6-370).
3 Uses a sector gear and shaft in place of
the roller and shaft in the worm and roller 26
gear. The sector is meshed with teeth cut 25
into the side of tne ball nut. 24 22

15 \ 13

16

21,4111W111

X:.
IMEAre'

4/5/ / "W
1
36-48

1 Worm Shaft 15 Worm (Integral with Shaft)

2 Thrust Bearing Adjuster 16 Worm Thrust Bearing, Upper
3 Adjuster Locknut 17 Worm Shaft Oil Seal
4 Steering Gear Housing 18 Side Cover Bolt
5 Clamp Retainer Screw 19 Lockwasher
6 Ball Guide Clamp 20 Side Cover
7 Back-up Adjuster 21 Lash Adjuster
8 Back-up Adjuster Locknut 22 Lash Adjuster Locknut
9 Ball Guide 23 Lash Adjuster Shim
10 Worm Thrust Bearing, Lower 24 Side Cover Bushing
11 Expansion Plug 25 Side Cover Gasket
12 Worm Balls 26 Housing Bushing
13 Sector Gear 27 Sector Shaft Oil Seal
14 Ball Nut 28 Sector Shaft

(6-370) Courtesy of Mack Truck Limited

Recirculating ball steering boxes are used on

a wide range of vehicles. However, they're not
used on heavier vehicles as much as worm
and roller steering gears. Recirculating ball
steering gears have a low-friction operation
and a simple design which makes them very
adaptable to power-assisted steering.

557
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:261

Cam and Lever Steering Gear When the steering wheel is turned, the cam
The cam and lever steering gear (Figure 6.
turns. The lever shaft studs, which are
engaged in the cam groove, follow the groove
371) has a tapered stud (single lever design),
or two tapered studs (twin lever design), and cause the lever shaft to rotate. The
rotating lever shaft sets the Pitman arm and
which engage helical grooves in a cylindrical steering linkage in motion to steer the vehicle.
cam. (The cam is similar to the worm used in
the recirculating ball steering gear). The The cam is mounted on ball bearings and the
studs are attached to an t.-shaped lever arm tapered studs are mounted on roller bearings.
that replaces the sector gear and shaft or Cam bearing preload is adjusted by a shim
roller gear and shaft used in the two pack between the upper cover and the
previously described steering gears. housing. End play of the lever shaft is con-
trolled by an adjusting screw mounted in the
side cover.
The cam and lever steering gear made by
Ross is very common in the heavy duty field. A
single lever model is made for smaller
UPPER COVER PLATE
AND SCREWS vehicles and a twin lever for larger ones. A
cam and lever gear is often used with power-
SHIM PACK
assist linkage steering. in which cap the
ROLLER
FILLER PLUG power-assist control valve will usually be in
BEARING the same location as the upper cover plate.
siva
NUTS UPPER BEARING Rotary movement of the cam and subsequent
CAM end thrust created by the lever shaft moves
the control valve to provide the power-assist.
LEVER SHAFT
FRONT SUSPENSION AND FRONT AXLES
Front suspension and front axles are an in-
tegral part of steering. Figure 6-372 shows an
assembled and a disassembled view of a
typical front suspension system. Suspension
OIL SEAL
components are discussed below:
HOUSING
SIDE COVER
ADJUSTING
NUT OWER BEARING

(6-371) PHANTOM VIEW OF SG 42

STEERING GEAR
Counesy of Mack Truck waded

t, REAR MOUNTING BRACKET

-0-- FRONT
0
EYE PIN
01J

FRI

SHOCK ABSORBER SHACKLE

LINK

FRONT MOUNTING
SPACER
BRACKET SPRING
AXLE

moss
U-BOLT
(6-372) Couiesy of General Motors Corporation

558
6:262 WHEEL MACHINE STEERING AND FRONT SUSPENSION

REAR HANGER
U-BOLTS

SHACKLE SHACKLE
LINK

FRONT HANGER
o
BUMPER --110 U-BOLT
SPACER

SHOCK
SHACKLE
SPRING ASSEMBLY O 0 PIN
LINERS
0
SPACER A-0479
BUSHING

(6-372) Courtesy of Genera; Motors Corporation

Spring Hanger Brackets Shackle Pins

Front and rear mountings for the springs. The pins that attach the front and rear of the
Usually they are made of cast steel and are spring to the hangers are called shackle pins.
bolted or riveted to the frame. The hardened steel shackle pins are the pivot
point for the spring as it flexes. Lubricated
Shackles shackle pins are drilled lengthwise and
crosswise to distribute grease between the
When a spring bends. the distance between pin and bushings.
the two spring eyes changes. If both ends of
the spring were fastened rigidly to the frame. Shackle Bushings
the spring would not be able to bend. To per-
mit the spring to flex, only one end is attached Shackle bushings are installed in the eyes of
rigidly to the frame while the other end is at- the spring, (front and rear) and in the spring
tached to a swinging support called a hangers. As the spring flexes. the eye of the
shackle. The shackle consists of two plates spring turns slightly with respect to the spring
called shackle links and two shackle pins hanger. The shackle pins and bushings must
(described below). One of the shackle pins fits permit this movement. Most heavy duty
through holes in the link ends and into the shackle Pins are drilled part way down their
spring hanger, while the other shackle pin fits length and across their diameter, and have a
through holes in the opposite end of the links grease fitting to lubricate the pins and
and through the spring eye. This assembly of bushings. Automobiles and light duty trucks
pins and links forms the swinging support. generally use a pin and bushing arrangement
When a load is put on the spring, the shackle that does not require lubrication. An
lets the spring swing out and thus flex. automotive bushing is made of an inner and
Usually the shackle is at the rear of the spring outer steel shell with a bonded rubber
as in Figure 6-372. bushing between the two. As the spring flexes
the rubber lets the spring eye turn slightly in
559
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:263

relation to the hanger. Since there is no metal A number of different types of shock ab-
across metal movement, no lubrication is sorbers have been made in the past, but the
needed Another function of The rubber center hydraulic shock (Figure 6-373) is the only one
of this bustling is to help dampen suspension in common use today. It is referred to as a
noise. directacting, telescoping shock absorber.
Shock absorbers are made in various sizes
Springs and strengths.
Heavy duty front suspension springs are
generally semi-elliptical. having multiple
leaves of graduated lengths. The width,
thickress and number of leaves, and the
overall length of the spring, are determined by
the type of vehicle the springs are used on.
The leaves are drilled at their centers and are
held together by a center bolt. The head of the
center bolt is round and fits into a correspon-
ding hole in the axle. The bolt thus acts as a
dowel holding the axle square with the frame.
Clips are placed at intervals along the spring PISTON ROD SEAL
PISTON ROD
leaves to keep the leaves in line. Often the
second leaf will have its end rolled around the
eyes of the main leaf to provide additional
support.

U-Bolts INNER CYLINDER

HEAD
ti
LIbolts attach the springs to the axle. Made of
good grade steel. they are bent, U-shaped, to RESERVOIR
INNER 111
the width of the springs and are threaded at CYLINDER
each end.
0-RING
Shock Absorbers
RECOIL 1

Springs alone cannot provide a satisfactory ORIFICE

RESTRICTION
ride and good steering control. When a PORTS
vehicle is stationary, the springs are com- PISTON
pressed to a certain degree by the weight of
the vehicle. This initial compression is called RECOIL VALVE
the spring's rest position. When the vehicle is VALVE SPRING
in motion and a wheel passes over rough
ground, the spring is forced to compress fur-
ther. After the vehicle has passed ove the
REPLENISHING
bump the spring rebounds in the opposite VALVE
direction, and then oscillates back and forth
until it stops at its rest position. This
oscillating spring action makes for poor
handling and riding characteristics, and some
way has to be found to limit it. The solution is
a shock absorber. (6-373)
One end of a shock absorber is attached to SHOCK ABSORBER
Courtesy 01 Ford Motor -;ousPeny
the frame and the other end to the axle. When
a wheel goes over a bump and the spring (and
the axle) start to oscillate, the shock absorber
picks up the oscillation from the axle and
counteracts it. By lengthening and shortening
with a counteracting force, the absorber slows
down and limits the amount of spring and axle
oscillation.

560
6:264 WHEEL MACHINE STEERING AND FRONT SUSPENSION

Shock absorbers basically consist of an outer STEERING AXLE

reservoir, an inner working cylinder, and a
piston and rod. The rod. attached to the The steering axle assembly consists of the
piston. extends through a seal at the top of the following parts:
unit and acts as the upper mount. The cylinder Axle center I-Beam or Tubular con-
is filled with oil and as the rod extends and struction
contracts the oil is forced to transfer from one
side of the piston to the other through restrict- Steering knucle pins (king pins)
ed ports in the piston. It is this movement of Steering knuckle (spindle assembly)
fluid through restricted ports that causes the
dragging action on spring oscillation. Steering linkage including:
A compression valve and replenishing valve steering arms
located in the bottom of the shock absorber drag link
connect the working cylinder and the reser- Pitman arm
voir. The compression valve relieves pressure tie rod
during compression and the replenishing tie rod ends
valve replenishes the oil in the cylinder during
extension. The piston rod seal wipes the rod Axle Center
of excess oil during extension and returns it to
the reservoir A shield. generally attached to A typical highway truck axle and knuckle
the outer end of the piston rod, extends down assembly is shown u Figure 6-374. Parts of
over the main cylinder and protects the rod the steering axle are discussed below.
and unit against rock damage.
There are varims ways of mounting shocks;
the most common for heavy duty woe. 's by
large round eyes at either end of the so.
absorber. Two tapered rub:,er bushings are in-
stalled in each eye and fit over the mounting
bolt. A nut and washer then holds the shock to
the mounting bolt. The rubber bushings give
some flexibility and dampen suspeAsion
noise.
Maintenance of .)cx absorbers inc -les
replacing rubber mounting bushings. end
tightening loose mounting bolts. Shock ab-
sorbers are not adjustable, no are they
repairable. :f one fails the complete unit must SPINDLE
be replaced. STEERING KNUCKLE

PITMAN
STEERING LEVER STOP SCREW
SPRING PADS
KING PIN '`-.....%.
(KNUCKLE PIN)
AXLE CENTER

_.-=a111.

TIE ROD

TIE ROD
.. TIE ROD - CLAMP 141.70

END
Courtesy of Mack Truck Lrintied
(6-374)
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:265
Cap Screw
There are two main types of axles: reversed 2 Cap (Upper)
Elliot and Elliot. The difference in the two lies 3 Kingpin
in whether the connecting yoke is on the axle 4 Bushing (Upper)
5 Sleeting Knuckle or
end or on the steering knuckle. On a reversed Spindle Assembly
Elliot axle (Figure 6-375). the yoke is on the 6 flushing (Lower)
steering knuckle whereas on an. Elliot axle 7 Cap (Lower)
8 Upper Grease Seal
(Figure 6-376). the yoke is on the axle end. (Rounded Edge Up)
The reversed Elliot is the most common axle. 9 Shims
10 Axle Center
11 Draw Key (Short)
12 Thrust Bearing
Assembly
13 Lower Grease Seal
(Rounded Edge Down)
14 Draw Key (Long)

.8

7 13--7-7*(;)
A441,

(6-375)
REVERSED ELLIOT AXLE
KNUCKLE HAS THE YOKE
AXLE Courtesy of General Motors Corporation
YOKE
DUST CAP

doKING PIN

BUSHINGS

TIE ROD STEERING

KNUCKLE

Courtesy of J.!. Case

0* (6-376) sssss

ELLIOT AXLE AXLE HAS THE YOKE

562
6:266 MINEEL MACHINE STEERING AND FRONT SUSPENSION

Steering Knuckle Pins (King Pins) A steering knuckle for a reversed Elliot Axle is
shown in Figure 6-377. This knuckle will have
Non-driving front axles can have straight bushings in the upper and lower pin bosses
knuckle pins or tapered knuckle Dins.(The two and the knuckle will turn around the pin on
axles in Figure 6-375 and 64 both have these bushings. (If the knuckle was for an
straight pins.) Straight knuckle pins are held Elliot axle the bushings would be in the axle
by tapered dowel keys (11) and (14) in Figure pin bosses.) Bushings may be bronze, steel
6-375). Tapered knuckle pins are drawn into backed bronze or plastic. Whatever their
position and held by a nut at the upper end of material, all bushings have grooves to allow
the pin. The pins are constructed of a high grease to flow uniformly to the high-pressure
grade steel and have a case hardened outer areas. Grease fittings are installed in both up-
surface for strength and resistance to wear. per and lower pin bosses. Note that instead of
bushings. some machines will use needle
Steering Knuckle and Bushings bearings as a bearing surface.

WHEEL SPINDLE

THRUST BEARING

SPINDLE ARM

TAPERED BOLT

TIE ROD END

(6.377) Courtesy of Rockwell International

Automotive Operations

563
... ......---..-

WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:267

Besides bushings or needle bearings at Tie Rod Ends

knuckle-axle connections, there is alsc either
a ball, a roller or a flat washer thrust bearing Tie rod ends (Figure 6-379) are swivel parts
which supports the weight of the vehicle and that connect the tie rod to the steering arms.
makes steering easier. In the knuckle in They're ball-socket assemblies that are spring
Figure 6-377, the thrust bearing is located be- loaded a- crimped together. Tie rod ends are
tween the lower pin boss and the axle. In the threadec to the tie rod, and are attached to
Elliot axle in Figure 6-376, the thrust bearing the steers. 'n by a tapered stud and nut. A
is between the upper pin boss and the dust cover is placed over the ball stud to keep
knuckle. out water and dirt. A grease fitting is located
at the bottom to lubricate the socket assem-
In addition to a connecting link with the axle, bly. Tie rod ends are usually replaced.
the knuckle has both a flange to which the although some of the larger ones can be rekit-
brake foundation assembly is attached and a ted.
wheel spindle. Wheel hubs are mounted on
the spindles on opposed tapered roller
bearings.

STEERING LINKAGE

Steering Spindle Arms ACLAMP

Spindle arms (Figure 6-377) connect the SSEMBLY
knuckle with the tie rod. The arms may either
be bolted or taper fit to the knuckle. The tie
rod ends have a tapered bolt which fits into a
corresponding tapered hole in the spindle
arm. The bolt is secured with a nut.

Ti. Roes CROSS STEERING

.64-11
64 SOCKET ASSEMBLY TUBE TIE ROD
The two spindle arms (and thus the two (6-379) TYPICAL BALL SOCKET
steering knuckle assemblies) are connected TIE ROD END
to each other by a tie rod (Figure 6-378). The
Courtesy of Mack Truck Limited
tie rod is threaded at each end and held
securely in position by clamp bolts. Right and
left hand or "differential" threads are provided
on the tie rod to correct wheel alignment. The
rod is generally tubular and can be either
straight or have a dropped center. In ,mall
vehicles multiple tie rods may be used, These
will require extra tie rod ends, and an idler
arm arrangement to support them,

5 ;.:- COTTER PIN

TIE ROD END NUT
BOLT

CLAMP TIE ROD

LOCK WASHER

SPINDLE ARM `'CLAMP

`CLAMP NUT
TIE ROD END ASSEMBLY
(6-378) Courtesy of Rockwell International
Automotive Operations

584
6:268 WHEEL MACHINE STEERING AND FRONT SUSPENSION

Drag Links Tilting the wheels is necessary to offset the

A drag link, as was seen earlier, connects the
side thrust of the grader's moldboard. By
tilting the wheels against the direction of
Pitman arm of the steering box to the spindle thrust, the wheels can dig in and thus reduce
steering arm. Most drag links have fixed ball- the tendency of the light front end to be
socket assemblies on the ends, and are pushed sideways. Another advantage of the
replaced as a unit. However, some large drag tilting wheels is a shorter turning radius that
links have replaceable ends that can be rek fit- allows the grader to make sharper turns.
ted. Maximum tilt on graders is factory set. usually
at 15°.
Grader Front Suspension
To get grader wheels to tilt requires some ad-
A note should be made here on grader ditional parts not seen on trucks. The main
steering since it differs from other wheel
additions are:
vehicles steering: grader front wheels not
only turn but also tilt. steering knuckle yoke assembly and
pivot bolt
rod to connect both assemblies
together
hydraulic tilt cylinder
A typical grade- steering axle assembly is
shown in Figure 6-381. The steering is power
controlled by two hydraulic cylinders. A thirc'
hydraulic cylinder tilts the wheels. One end of
the tilt cylinder is attached to the axle assem-
(6-380) bly, and the other end to one steering knuckle
C.-xi:Fen 0 Road Machinery Lirmied yoke assembly. Since both steering knuckle
assemblies are connected by a solid rod,
movement of the cylinder tilts both wheels
together.

o,
STEERING CYLINDERS TIE ROD
4140,
poh
TILT CYLINDER

KING PIN

WHEEL TILT
MOT BOLT

FRONT AXLE PIVOT

BEARING
STEERING KNUCKLE
(SPINDLE)
(6-381)
Courtesy of Champion ' *" Machinery Limited

565
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:269

POWER STEERING Reduce the tendency to make un-

wanted turns or to turn too quickly. The
In the past most cars used manual steering. wheel should turn only as fast as the
Many highway trucks and industrial machines steering wheel is turned, and only as
also had manual steering. In modern times the far.
trend has been towards power-assist or full-
power steering. The reason for this change is Basic Parts Of A Power Steering System
mainly the ease of operation that power gives
to steering. On vehicles that normally use 1. A pump capable of delivering a volume of
manual steering, such as cars and some high pressure oil.
trucks, power steering provides easier
maneuverability. especially in and out of tight 2 A reservoir to store the required volume of
spaces. On large off-highway vehicles, power oil.
steering is a necessity. The weight of these 3. Hoses to carry the pressurized oil.
heavy machines, their large tire- ground con-
tact area, and the soft uneven ground they 4. Hydraulic cylinder(s) to convert hydraulic
work in. an would make them very difficult to p ssure to mechanical force and
steer manually. Note that the ease of m:;vement.
operation that power gives to steering could
also be gained by using higher gear ratios. 5. A pressure relief valve.
The problem with the high ratios is that what 6. A flow control valve.
would be gained in ease would be lost in
speed. The steering would be too slow, 7. A directional control valve.
requiring many turns of the steering wheel to
turn the wheels. One other advantage of
8. Fluid. A.T.F. or a similar type of oil.
power stewing is that it gives better steering
control at higher speeds. A typical power-assist steering system is
shown in Figure 6-382. Power-assist. often
Power steering may be either power-assist, referred to as linkage power steering. is
full-power. or hydrostatic. All three types of basically a manual steering system with a
power steering must: booster cylinder added. A steering valve
(spool valve) located in the drag link senses
Give the operator a feel of the road. steering force. When driver effort at the
Steer manually if the source of assist steering wheel reaches a certain point, the
fails, or have a back up emergency valve is activated and sends pressurized oil to
system in case of power failure. the booster cylinder to aid in the turn. When
the steering force drops below this point. the
POWER-ASSIST STEERING assist ceases as the valve piston returns to its
center position stopping the flow of oil. Be-
STEERING
cause steering effort with power-assist
STEERING VALVE steering is proportional to the force requir'd
GEAR LEVER
to turn the wheels. it gives the driver a good
feel of the road.
TO RESERVOIR
TO CYLINDER
L.H. TURN
Road shocks, as well as driver turning force.
FROM PUMP may also activate the power-assist steering
valve. Reacting to road shocks, the valve sets
TO CYLINDER the booster in action to counteract the shock
R.H. TURN
forces.

FRONT AXLE

TIE ROD BOOSTER CYLINDER CLAMP

104.10
(6.382) Courtesy of Mack Truck Li.nitea

566
6:._70 WHEEL MACHINE STEERING AND FRONT SUSPENSION

Booster cylinders contain a piston attached to The description given here is an example of
a rod that protrudes through the end of the one type of power-assist steering. Other
cylinder. The cylinder is usually mounted with manufacturers will have different
its fixed end anchored to the front axle and arrangements of me parts. Whatever the
the piston rod clamped to the tie rod. design, though. all power linkage systems
However, some powerassist linkage steering have the common purpose of providing an
systems have the cylinder and control valve assist for turning.
mounted as an assembly within the drag link.
Each end of the double-acting booster cylin- FULL POWER STEERING
der has a port so that steering fluid can be
directed into it. Fluid sent to one side causes In power-assist steering a control valve and
the booster piston to exert a force on the tie power cylinder are added to manual linkage
rod in a left direction, fluid to the other side to reduce the effort needed to turn the vehicle.
causes the piston to exert a force on the tie The power-assist. in effect, is tacked onto a
rod in a right direction. As steering fluid is ad- manual steering system. In full-power
mitted to one end of the cylinder during a turn. steering. on the other hand. the power assem-
fluid in the opposite end is discharged to the bly is an integral part of the system because
steering valve and from there goes back to the booster cylinder and control valve are in-
the reservoir. corporated within the steering gear box. The
gear box on full-power steering acts as a
Some booster cylinders relieve pressure hydraulic cylinder. Note in Figure 6-383 that
automatically as the piston nears either end of oil is fed directly into the steering box. A full-
its stroke. Relief is accomplished by a taper at power system is dm) called integral power
each end of the cylinder bore (the end of the steering.
bore is larger than the center) so arranged
that as the piston approaches the end of its
stroke. the taper allows the fluid to bypass the
piston. thereby reducing the pressure and
limiting the force the piston can exert. This RESERVOIR
(INTEGRAL
feature automatically eliminates damage to wITH PUMP)
the cylinder and steering linkage. and
prevent:: overheating of the steering fluid and PUMP OUTLET
pump.
As a safety precaution. booster cylinders be-
come neutralized if the pump fails. Without
pump pressure oil would flow from one end of
the cylinder to the other, and the booster
would have no effect on steering. The vehicle
can be steered manually. albeit with con- POWER

siderably more effort. STEERING

GEAR
FRAME
...Z.--
STEERING GEAR
INLET

" ___
STEERING GEAR -
OUTLET 0
STEERING GEAR
LEVER STEERING
LEVER

DRAG LINK 20091

(6-383)
Courtesy of Mack Truck !Amsted

567
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:271

The Sheppard steering gear box described When the wheels are straightened after a turn,
here is one of a number of types available; it the activating valve centers, and the hydraulic
consists of four basic parts: the actuating power no longer acts on the steering. Thus
shaft. the actuating valve, the actuating piston the driver has a good feel of the road when
and the output shaft (rigure 6-384). the vehicle is moving straight ahead.
ACTUATING Another important part of the Sheppard in-
SHAFT AND ACTUATING tegral power steering discussed here is the
SEARING VALVE titett messing - set of relief valves. These two valves are
RELIEF RELIEF
PLUNGER VALVE . VALVE
PLUNGER located in the piston and are activated by
--"- i.-L plungers at each end of the cylinder housing
(Figure 6-384). Either one or both of the
plungers is adjustable. Correct setting of the
plungers will be dealt with in future training.
In operation, the valves serve to relieve
hydraulic pressure as the piston approaches
the end of the housing. A valve bail it; un-
STEERING COLUMN seated by the portion of the plunger which ex-
tends into the cylinder. When the ball is off its
ACTUATING seat, pressure cannot be built up. This feature
PISTON OUTPUT SHAFT
AND GEAR prevents overloading of the hydraulic system
and controls the degree of turn. The relief
NEUTRAL POSITION X414.
valves also allow the vehicle to be steered
(6-384) manually if the pump fails.
Courtesy of Mack Truck Limited
Full-power steering systems are made that
have dual steering boxes (Figure 6-385). The
The actuating shaft is connected to the box connected to the steering wheel is the
steering column and thus to the steering control, while the second one is a slave cylin-
wheel. The shaft rotates whenever the der. The two steering boxes work together to
steering wheel is turned. The actuating shaft give an increased steering force.
has a multiple start thread which is engaged
with a similar thread in the actuating valve.
The piston has a gear surface called a rack
gear cut on one side of it that is meshed with
a gear splined to the output shaft. The output
shaft has the Pitman arm attached to it. When
the actuating shaft is rotated by the steering
wheel, resistance created by the vehicle's
wheels to the turn causes the actuating valve
to move slightly (maximum 1/321 within the
piston.
The valve is fitted to a very fine tolerance in a
bore in the piston. As the valve moves in
response to steering wheel movement. landS
and grooves on its outer diameter alternately
cover or uncover ports in the piston. As these
ports are covered or uncovered, fluid.
pressurized by the pump. is directed to the
correct end of the piston while at the same
time fluid at the opposite end of the piston is
returned to the reservoir. As the piston moves
back and forth the output shaft is forced to
rotate, moving the Pitman arm and thus
providing the linear motion to turn the front
wheels. A small effort on the steering wheel of
this full-power system has resulted in a large
effort being applied to the wheels.

568
6:272 WHEEL MACHINE STEERING AND FRONT SUSPENSION

,,v SECONDARY (SLAVE) GEAR

Cr RETURN
SLAVE

a,. RESERVOIR
"N
J IFOR PUMP
LINE NO. 2 UNE No. 1-0'
STEERING GEAR
PIMP
INLET LINE i

1=1 .....1
i
RETURN LINE TO L STEERING COLUMN
SECONDARY
(SLAVE) GEAR

MAIN STEERING GEAR

SCHEMATIC OF
DUAL INTEGRAL POWER
STEERING GEAR SYSTEM
(6-385) Courtesy of International Harvester
MT-20625
A full-power steering system for a grader can
be seen in Figure 6-386. which shows the
machine's full-hydraulic system. The steering
parts are numbered. The steering box (5) is

....
', mounted on top of the axle bolster. A shaft ex-
tends down through the bolster to connect
with the steering arms. The oil flow in the
steering system is as follows: the oil is drawn
from the reservoir (1) through the screen (2) to
the steering pume (3); from the pump the oil
flows through the steering relief MVO (4) and
into the steering box (5). Return c.l from the
steering box flows back to the reservoir. If II

(6-386)
1Hydraulic systems reservoir. 2Hydraulic
screen. 3 Steering pump. 4Steering
relief valve. 5Steering box.
SHAFT CONNEGING
WITH STEERING ARMS
Courtesy of Champion Road Machinery Limited
569
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:273

steering box is overloaded, the relief valve The oil flow in this Char-Lynn hydrostatic
opens and the oil bypasses the box and steering system. with the steering wheel in
returns to the reservoir. Operation of the neutral, is as follows: The steering pump (3)
steering box is similar to that described for draws oil from the hydraulic systems reservoir
the Sheppard integral system. (4). From the puma the oil flows through the
pressure relief valve (2) to the steering unit
Both full-power (integral) steering and power- (1). From the steering unit the oil returns to
assist (linkage) steering are generally used the reservoir via the double filter assembly
on-highway trucks of all sizes and on off - (10) and a one-way valve not shown. The one-
highway vehicles such as logging and gravel way valve prevents the oil from escaping out
trucks Many types of industrial equipment of the reservoir when the filter elements are
also use full-power and power-assist steering changed. The steering unit is simply a direc-
tional valve that directs oil to the steering
HYDROSTATIC STEERING cylinders (7 and 8) as the steering wheel is
rotated. For example, if the wheel was turned
Hydrostatic is a third type of power steering. It to the left, oil would be directed to the piston
is used mainly on slow moving venicles such rod end of the L.H. cylinder (8) and the anchor
as graders, loaders. scrapers, fork lifts and end of the R.H. cylinder (7), resulting in the
large off-highway haulage trucks. Often wheels being turned to the left. Return oil
hydrostatic steering is also used on ar- flows from the anchor end of the L.H. cylinder
ticulated maines. and the piston rod end of the R.H. cylinder
In hydrostatic steering, as opposed to full- back to the steering unit.
power or power-assist steering. the steering The steering cushion valve (6) cushions shock
wheel is not mechanically connected to the loads that the front wheels are subjected to
wheels. Turning the steering wheel moves a and thus protects the steering cylinders.
control valve that directs oil to either a right
or lel turn hydraulic cylinder These cylinders The filter assembly (10) consists of two filter
supply the force needed to turn the machine. elements, one 10 microns and the other 40,
A hydrostatic steering system for a grader is which should be changed when the indicator
shown in Figure 6-387. It uses an orbital on the filter head is in the red.
steering control valve made by Char-Lynn.

1 Char-Lynn Staenng Ilni1

2 Steering System Relief Valve
3 Steering System Oil Pump
4 Hydraulic Systems Reservoir
5 Main Hydraulic Manifold
6 Steerinc Cushion Valve
7 R.H Steering Cylinder
8 L.H. Steering Cylinder
9 Front Axle Assembly
10 Filter Assembly
(6-387)
Counesy of Champion Road Machinery Limited

570
 6 ......ee 4...

6:274 WHEEL MACHINE STEERING AND FRONT SUSPENSION

A satety precaution is built into this

hydrostatic steering system. If the pump
should fail, the pressure line closes off and
the steering unit. when the steering wheel is
rotated, functions as a pump. The steering
unit will draw oil from the return line :allowing
the grader to be brought safely to a stop.
A typical hydrostatic steering /stem for a
large oft-highway truck is shown in Figure 6-
388. It usethe same hydraulic oil tank (4) for
its, source of supply as does the main
hydraulic system. The steering system con-
sists mainly of the Orbitrol steering valve (7),
rotary shut-off valve (6), flow regulator and
relief valve (3), double relief valve (9), steering
boosters (1 and 8). pump (2), and mechanical
linkage on the front axle.

(6-388)
t R.H. Steering Booster
2 Oil Pump
3 Flow Regulator & Relief Valve
011 Tank
., Steering Wheel
6 Rotary Shut-off Valve
7 Orbitrol Steering Valve
8 L.H. Steering Booster
9 Double Relief Valve
Courtesy of Terex. General Motors Corporation

571
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:275

Some articulated loaders and scrapers have 2. Moves the control valve to counteract
hydrostatic steering. The hydraulic steering road shock.
control used on these machines consists of
(1) a mechanical steering assembly coupled When making a turn on one of these ar-
by linkage to a hydraulic valve mechanism. ticulated machines. movement of the steering
and (2) a mechanical link connected between wheel. left or right. causes the worm. con-
the steering gear assembly and the rear main nected to the steering shaft. to turn inside the
frame section. referred to as the follow-up restraining nut gear The resistance created
linkage (Figure 6-389). This follow-up linkage causes an endwise movement of the steering
should not be confused with the steering shaft and hence a movement of the hydraulic
linkage described earlier that transmitted ac- control valve. The valve directs oil under
tual steering force. the only parts that trans- pressure to the head end and rod end of op-
mits turning force on these machines are the posite cylinders. causing the machine to ar-
hydraulic cylinders. ticulate and steer in one direction. The
moment the operator releases the effort on the
Follow-up linkage is connected to the sector steering wheel. the follow-up linkage. by way
shaft at one end. and to the frame via an arm of the sector gear. nut gear and steering shaft.
at the other end. This linkage: returns the control valve to neutral. holding
1 Aids in returning the control valve to a the machine at the desired angle of turn.
neutral position after a turn.
STEERING HYDRAULIC SYSTEM
11.11 sott %IP OH 1= KV" Olt
WC( P.4011 Mr Oil

lAtOAOSNO Pat STIon itESSIM NIKO

$14141%6Crt5V.40$ sg Pow IISTPOIM

45114
'04414A1011
%TO

vevt4t,T..
LP .1
_ I

Am%
re6gROt
..11141 *AMP

STEERING SYSTEM SCHEMATIC

(STEERING CIRCUIT IN NEUTRAL AND ACCUMULATOR CHARGED)
1 Sector gear. 2Steering shaft 3Nut gear. 4Followup link, 5shims (unloading). 6Unloading valve. 7Orifice. 8Pilot v..Ivo.
9Pilot relief valve. 10Shims (pilot relief s. Ave). 11 --Dump valve (large pump). 12Dump valve (small pump). 13Orifice. 14 Ball
check. 15Spool. 16 Orifice. 17Orifice. 18Check valve,
(6.389) Courtesy Caterpillar Tractor Cc

572
 6:276 WHEEL MACHINE STEERING AND FRONT SUSPENSION

EMERGENCY STEERING SYSTEMS FOR Pump Driven By An Electric Motor

HYDROSTATIC STEERING
The electric emergency steering system has
Hydrostatic steering systems have no direct an electrically driven hydraulic pump that fur-
mechanical linkage between the steering nishes sufficient flow and pressure to give the
wheel and the road wheels A few years ago, a operator enough steering control to stop the
law was passed making an alternate or vehicle. A switch in the operator's com-
emergency method of steering mandatory in partment activates the pump. This system is
the event of an engine or pump failure. designed for emergencies only and not for
continuous service. An emergency steering
Three emergency steering methods commonly
system can be seen in Figure 6-390 as part of
used on hydrostatic steering are:
the steering system of a large off-highway
orbital control dump truck. Notice how the emergency circuit
is piped into the main steering system. When
pump driven by an electric motor
the emergency circuit is activated,
hydraulic accumulator pressurized oil flows from the emergency
steering pump to shift the shuttle valve. cut-
Orbital Control ting off the main hydraulic pump and flow
divider from the system. The oil then travels to
As was mentioned earlier, in the event of an
the steering control valve and steering cylin-
engine or pump failure on an orbital steering
system. rotation of the steering wheel con- ders and then the vehicle can be safely
verts the internal components of the orbital steered to a stop.
valve into a rotary pump providing enough
control to safely bring the vehicle to a stop.
R. H. Steering
L. H. Steering
Cylinder
Cylinder

Steering
Control Valve

Hydraulic
0../ Pump
N
Flow Divider Emergency
Steering
Piping
Hoist
Relief Emergency
Valve Steering
Pump
Steering ji 11)
Relief Oil Filter
Valve

Quick Release Shuttle Valve

Valve

Hydraulic Tank
(6.390)
Courtesy of Wabco Construction and Mining Equipment

573
 ..-e..10,..... -....

WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:277

Hydraulic Accumulator STEERING GEOMETRY

An accumulator, as seen in Block 3, Steering Geometry refers to the angular
;.Iydraulics is a cylinder with a precharge of relationship between the front wheels,
nitrogen g.s that is connected into the main steering linkage, and frame. Factors in
hydraulic system to absorb shocks and store steering geometry are:
pressurized oil
Caster
Oil pressure from the steering hydraulic pump Camber
enters the accumulator through a port on the
end of the cylinder and compresses a piston Toe-in
against nitrogen gas. The oil pressure thus Toe-out on turns or turning radius
opposes the gas pressure. As long as oil King pin or steering axis inclination
pressure is maintained in the system, the
pressure is maintained against the nitrogen Each of these factors affects vehicle steering
gas. If the oil pressure fails, fcr some reason, and all but caster influence tire life.
the nitrogen precharge will exert a reverse
pressure in the system. The reverse pressure Caster
flow, diverted by the accumulator valve to the
steering control valve, supplies temporary oil Caster is the backward or forward tilt of the
pressure for a short period of steering, usually king pin or spindle support arm. Caster is a
for two or three full turns. A check valve in the directional control angle measured in degrees
accumulator valve prevents the accumulator and is the amount the centerline of the spin-
pressure from reaching the steering pump. dle support arm is tilted from true vertical.
Tilting the spindle support arm back gives
front wheels the tendency to maintain straight
ahead position by projecting the centerline of
the support arm to a lead point which is ahead
of the point of contact of the wheel. Caster is
not a tire wearing angle.

Cr' TRUE VERTICAL

CENTERLINE
OF SPINDLE SUPPORT CASTER ANGLE (POSITIVE)

SPINDLE SUPPORT
FRONT OF CAR

LEAD POINT
WHEEL CONTACT POINT

COutteSy of Snap.On Tools

Of Canada Lunded

(6-391)

574
6:278 WHEEL MACHINE STEERING AND FRONT SUSPENSION

Caster is obtained on trucks by placing Camber

tapered shims (one on each side) between the
axle center spring saddles and the spring Camber is the inward or outward tilt of the
(Figure 6.392). When the shims are placed so wheel (in degrees) from the true vertical when
that the king pins are tilted back. the caster the wheels are straight ahead on a level
angle is said to be positive. When the king pin plane. Camber is a tire wearing angle. The
tilts forward the caster angle is negative. camber angle formed when the wheel is tilted
There are advantages and disadvantages to outward at the top is said to be positive. When
both angles. Trucks generally have positive the wheel is tilted inward the camber is
c aster. negative. Only positive camber is used on
vehicles. The purpose of camber is to:
The purpose of caster is to aid directional
control of a vehicle. Caster does this by bring the road contact of the tire more
creating a tendency in the front wheels to nearly under the point of the load. thus
both maintain a straightahead position and reducing stress on tile axle parts.
return to a staightahead position after a turn. provide easy steering by having the
Caster also helps offset road crown. weight of the vehicle borne by the inner
wheel bearing and spindle.
Incorrect caster can cause the following
steering problems: prevent tire wear
help to eliminate road shock.
Unequal caster causes the vehicle to
pull to the side of the last caster VERTICAL 00
Too little caster causes wander and CENTERL INE O F
weave POSITIVE CAMBER WHEFL
Too little caster causes instability at
high speeds
Too much caster causes hard steering
Too much caster causes excessive
road shock and shimmy

(6.393)
POINT OF LOAD

0
-8 IRON?
0
0

SHIM
AXLE
Aros3

(6.392) Courtesy ). General Motors Corporation

5 75
 .....0..

WHEEL !AACHINE STEERING AND FRONT SUSPENSION 6:219

Since camber is built into a rigid axle, it will The purpose of toe-in is to offset the small
not change unless the axle takes on a per- deftections in the front suspension and
manent set from overloading or severe steering linkage when the vehicle is moving
usage, or becomes bent or twisted by hitting forward. It ensures parallel rolling of the front
an obstruction or colliding with another wheels and tires and minimizes tire wear from
vehicle. scuffing. A toe-in error of 1/8 of an inch is
equivalent to dragging the tire crossways 11
Camber may be checked with a wheel feet for each mile the vehicle is driven. To ob-
aligning gauge or by measuring the angle tain maximum tire mileage, the running toe-in
formed between the outer edges of the wheel should be zero. The stationary toe-in of a
and a square resting on the floor. vehicle should be just enough to offset the
The harmful effects of incorrect camber are looseness, and spreading action in the
excessive wear to: linkage, caused by camber, when the vehicle
is being driven forward.
ball joints or king pins
Trucks using bias ply tires generally call for
wheel bearings 1/16 inch toe-in, while those using radial ply
excessive wear on one side of the tire tires call for a zero toe-in. Toe-in amounts for
tread; inside tread wear is caused by automobiles are somewhat higher due to their
negative camber. outsid: wear by more flexible front suspension.
positive camber. Note that although, as
was said abce, only positive camber is
used. Over a period of time of wear and
tear negative camber will start to ap-
pear.

Toe-in
Toein is the distance that the front of the
front wheels are closer together than the rear
of the front wheels (the distance B minus A in
Figure 6-394). Conversely. toe-out is the
distance the front of the front wheels are far-
ther apart than the rear of the front wheels.
Toe-in is considered the most serious tire
wearing angle. Incorrect toe-in (or toe-out)
appears as a feather-edged scuff across the
face of both tires. Because of its harmful ef-
fect on tires, it is extremely important that toe-
in be checked carefully.

(6.394)

Courtesy of Kenvottli 'muck Company

576

.1.
 6:280 WHEEL MACHINE STEERING AND FRONT SUSPENSION

Turning Radius (Toe-Out On Turns) King Pin Inclination

When rounding corners, the front and rear King pin inclination (K.P.I.) is the tilt of the
wheels must turn about a common center with king pin or ball joint steering axis toward the
respect to the radius of the turn (Figure 6-395). center of the vehicle. (Caster is the tilt of the
The front end design of most motor vehicles is king pin toward the back of the vehicle)
such that thr. Iron! wheels pivot independently
and at different distances from the center of The purpose of K.P.I. is to:
the turn. This makes it necessary to have the bring the extended centerline of the
wheels turn at different angles. The inside pivot closer to the center of tire-road
wheel, being ahead of the outside wheel, must contact and thus reduce the scrub
turn at a sharper angle than the outside wheel radius (Figure 6-396).
in order to remain perpendicular to the radius
and prevent the tires from scrubbing. The give the vehicle straight ahead direc-
sharper turning angle of the inside wheel is tional stability.
called toe-out on turns. Toe-out on turns is ac- King pin inclination adds to directional
complished by bending the steering arms stability in the following way:
slightly inward toward the center of the
vehicle. When the front wheels are turned to the
right or left, the spindle revolves around
Note that toe-out on turns does not affect the the pivot. Because of the angle of the
wheels in straight ahead position. The wheels pivot, the end of the spindle describes an
must return to their original parallel position arc. The ends of the arc are closer to the
after the tern is completed. road surface than the top of the arc
CENTERLINE OF REAR AXLE (Figure 6-397). Since it is impossible for
the end of the spindle to get closer to the
road surface because of the wheel and
tire, it follows that the front of the vehicle
must be slightly raised when the wheels
are turned from the straight-ahead
position. Because of the effort needed to
raise the front end on turns, the wheels
will have a resistance to turning and tend
ANGLE.
to travel straight-ahead. Also, after a turn
-el
INSIDE WHEEL the wheels will have a tendency to return
23' to a straight-ahead position as the weight
TURNING of the vehicle at the axle will be moving
RADII 20' from a higher to a lower position. A similar
principle is used when a door is hung at a
ANGLE. OUTSIDE WHEEL slight angle: the door, when unlatched,
won't open by itself and will have a ten-
dency to close if left open. Note that the
resistance to turns caused by K.P.I. is not
enough to cause hard steering.

COMMON CENTER TRUE VERTICAL

BALL JOINT ANGLE---
(6-395) TURNING ABOUT A COMMON CENTER (K.P.I.)
(K.P.1.)
Courtesy of Ford Motor Company
:(11111

Toe-out on turns is not adjustable, and any

deviation from specifications would indicate

1
bent steering arms or bent. worn. or damaged
linkage. Improper toe-out on turns will result
in tire wear similar to that caused by improper
toe-in adjustment POINT OF CONTACT
11
(6-396) KING PIN OR BALL JOINT INCLINATION
Courtesy of Ford Motor Company

577
,%
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:291

Caster, as discussed earlier. is the tilt of the WHEEL BALANCE AND UNBALANCE
. king pin toward the back of the vehicle.
Caster. therefore, has an effect on K.P.I. The Proper tire and wheel balance is essential for
effect, though, is not significant, since caster good steering and handling. Unbalanced
angle is generally small. wheels and tires can result in shimmy and
erratic steering conditions. There are three
types of wheel unbalance: static. kinetic, and
dynamic.
Static
A static unbalance condition exists in a wheel
when (1) the wheel has a heavy spot. and (2)
the wheel is not rotating. A wheel is said to be
in static balance when it has the weight
AXLE POSITION ON TURN equally distributed around the circumference
(i.e. it has no heavy spots) in such a manner
that there is no tendency for the wheel to
rotate by itself when it hangs free (Figure 6-
398). Conversely, if a wheel has static un-
balance, it has a heavy spot(s) that would
cause the wheel to rotate so that the heavy
I spot rests at the bottom.
AXLE POSITION STRAIGHT-AHEAD

(6-397)
Courtesy of Ford Motor Company

Like camber, king pin inclination is fixed by

the design of the axle and will not change
unless the axle has been bent from
overloading or Impact forces. King pin in-
clination may be checked with a wheel
aligning gauge.

A REFERENCE MARK HAS BEEN PLACED ON

BALANCED TIRE THE TIRE AND WHEN THE TIRE IS MOVED TO
SEVERAL DIFFERENT POSITIONS IT WILL STAY
IN THE POSITION IN WHICH IT IS PLACED.
(6-398) Courtesy of Ford Motor Company

578
6:282 WHEEL MACHINE STEERING AND FRONT SUSPENSION

Kinetic and Dynamic

Kinetic and dynamic unbalance conditions
occur in a wheel when (1) static unbalance
condition exists in the wheal. and (2) the
wheel is rotating
The relationship between kinetic and dynamic
unbalance depends on the location of the
heavy spot en the wheel. If the heavy spot is
located exactly on the centerline of the wheel
(Figure 6-399), only kinetic unbalance occurs.
0 the heavy spo is located toward either side
of the centerline of the wheel (Figure 6-399).
both dynamic unbalance and kinetic un-
balance occurs.
Kinetic unbalance causes up and down
vibration. Dynamic unbalance causes side to
side vibrations. Since kinetic and dynamic un-
balance usually occur together, the resulting
vibrations are a combination of up and down
and side to side vibrations. A wheel with
dynamic or kinetic unbalance can be balan-
ced by placing weights on the wheel rim 180
degrees away from the heavy spot. Cen-
trifugal force acting on the weights will equal
tne centrifugal force acting on the heavy spot
and cancel out the forces trying to move the
wheel's rotating axis.
An unbalanced wheel causes tire wear. The
tire on a wheel that is run unbalanced for
sometime will have a wavy tread surface.

CENTERLINE Li-CENTERLINE
OF WHEEL OF WHEEL

HEAVY SPOT HEAVY SPOT

S a;
!II
I SIDE TO SIDE
i
AND
UP AND DOWN \\\ =,,...=..dr_._.--) UP AND DOWN
VIBRATION VIBRATION

KINETIC UNBALANCE DYNAMIC UNBALANCE

(6-399)
Courtesy of Ford Motor Company

579
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:283

QUESTIONS WHEEL VEHICLE STEERING 10. Unlike those on automobile& most heavy
duty spring shackle pins and bushings
1. Through the actions of the steering gear have
in a manual steering system, rotary
motion of the steering wheel is converted 11. A leaf spring is properly located on the
to: axle mounting pad by means of the:
(a) vertical motion of the linkage (a) spring hanger
(b) sideways motion of the linkage (b) center bolt
(c) linear motion of the linkage (c) spring shackle
(d) one-way motion of the linkage (d) rebound clips
2. Synchronized movement of the two 12. The purpose of shock absorbers is to:
wheels is accomplished by connecting
them together with a: (a) help the spring support the load
(b) act as an overload device
(a) drag link
(c) control spring oscillations
(b) steering arm
(0) sway bar 13. True or False? A shock absorber works
on the principle of a drag being created
(d) tie rod when fluid moves through restricting
3. The drag link connects the: orifices.

(a) steering knuckles together 14. On a vehicle with e- reverse Elliot front
axle. the thrust Searing is positioned be-
(b) steering gear to the cross shaft tween the steering knuckle and:
(c) Pitman arm to the tie rod
(a) the top of the a, le eye
(d) Pitman arm to the steering control
(b) the bottom of the axle eye
arm
(c) either (a) or (b). depending on the
4. What are the three basic types of wheel machine
vehicle steering systems?
15. What is the brake foundation assembly
5. What are the three common types of attached to?
manual steering gears used in heavy
duty equipment. 16. Are there any grease fittings at the axle
knuckle connection?
6. True or False? Recirculating ball
steering gears are more common on 17. Compared to other wheel vehicle
heavy duty vehicles than worm and roller steering systems, what additional func-
steering gears. tion must grader steering perform?
7. The worm on a worm and roller steering 18. A is used to
gear is shaped, whereas tilt the front wheels on a current grader.
the worm on a recirculating bail gear is
19. Besides giving ease of operation, power
steering is necessary on large off-
8. A cam and lever steering gear uses: highway equipment because of difficult
steering caused by:
(a) a sector gear
(b) a roller gear (a; the weight of these machines
(b) their large tire-ground contact area
(c) a lever and stud srrangement in-
stead of a gear (c) the soft uneven ground they work in
(d) any of the three can be used (d) all of the above are correct

9. Why is a swinging shackle needed on a 20. What are the three basic types of power
leaf spring? steering?
21. What are the two locations where the
booster on power-assist (linkage)
steering is located?

680
6:284 WHEEL MACHINE STEERING AND FRONT SUSPENSION

22. In a linkage power steering system, the 32. True or False? Positive caster helps
spool valve is located in the: keep the wheels moving straight- ahead.
(a) steering gear 33. Positive camber is created by:
(b) steering box (a) tilting the axle or spindle assembly
(c) power piston backward
(d) steering linkage (drag link) (b) an angle in the axle that tilts the top
of the wheels outward.
23. Another name for full-power steering is (c) using a larger inner wheel bearing.
34. True or False? Camber is a tire wearing
24. On integral power steering, the control angle.
valve is located in the:
(a) tie rod 35. Excessive wear to the outside of a tire
tread indicates too much:
(b) steering box
(c) drag link (a) positive caster
(d) steering shaft (b) positive camber
(c) negative caster
25. How does a hydrostatic steering system
differ from linkage or full-power (d) negative camber
steering? 36. An Incorrect camber setting on a rigid
26. What happens in the steering unit (i.e., front axle:
the orbital control valve) of a hydrostatic (a) cannot be adjusted without bendi ig
steering system when the steering wheel the axle
is turned?
(b) can be adjusted by shimming the
27. True or False? The follow-up linkage axle
used in steering on some articulated (c) can be corrected by changing the
machines trans-nits all the steering force size of the inner wheel bearing
between the two frame halves.
(d) can 'be corrected by installing a
28. What is the function of the emergency spindle of a different angle
steering system on hydrostatic steering?
What are the three common types of 37. Toe-in on a solid axle truck suspension
emergency systems? can be adjusted by:
29. Br;efly explain the term steering (a) shimming the spring pad and spring
geometry. pack
(b) bending the axle
30. Caster may be defined as:
(c) adjusting the length of the drag link
(a) the inward or outward tilt of the
wheel (d) adjusting the length of the tie rod
(b) sideways inclination of the king pin 38. True or False? Toe-out on turns is
achieved by having the steering arms
(c) forward or backward tilt of the k'ng
pin
bent slightly inward toward the center of
the vehicle.
(d) none of the above
39. The purpose of king pin inclination is to:
31. When a caster shim is placed so that the
thick end of the shim faces the rear of (a) offset negative caster
the vehicle. the vehicle has: (b) provide a means of adjusting caster
(a) positive caster (c) make turning easier
(b) negative caster (d) bring the steering pivot axis nearer
the center of tire-road area contact
(c) increased K.P.I.

581
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 8:285

40. A wneel with a heavy spot is

41. A static wheel balance machine checks

the wheel for To check
wheel balw.oe dynamically, the wheel is
spun and inspected to see if it

42. Is a heavy spo. was exactly on the cen-

terline of a rotating wheel, what kind of
unbalance would exist and what kind of
motion would occur in the wheel?
43. An unbalanced wheel can be corrected
by placing the right amount of weight on
the rim'
(a) 80° from the heavy spot
(b) 100` from the heavy spot
(c) 180° from the heavy spot
(d) 90° from the heavy spot.

582
6:286 WHEEL MACHINE STEERING AND FRONT SUSPENSION

MAINTENANCE AND SERVICE REPAIR OF Also. as nart of scheduled maintenance on

WHEEL MACHINE STEERING AND a steering system. the steering gear should
FRONT SUSPENSIONS be checked for wear and adjusted as required.
Adjustment is necessary when back lash at
DAILY, ROUTINE MAINTENANCE the steering, gear is perceptible within three
quarters of a turn to either side of center.
Steering and suspension are directly related However, check for loose linkage or wheel
to safe vehicle operation and therefore should bearings before proceeding with a steering
be checked regularly. Daily, routine checks gear adjustment.
for the steering and front suspension will in-
clude checking for: The only adjustment generally done to manual
steering boxes on the vehicle is to adjust sec-
Correct tire pressure. Also check that tor backlash. The term sector backlash refers
tires are in good operating condition. to worm and roller, and cam and lever
Loose wheel lugs, broken or missing steering gears (as well as to recirculating ball
wheel nuts and studs. steering gears even though they technically
Loose. damaged or bent steering don't have a sector gear). To make this ad-
linkage. justment it is best to raise either the vehicle
so that the wheels are clear of the floor or
Oil leaks that may have developed disconnect the drag link. The adjustment is
around power steering parts. made with the wheels in the straight-ahead
Loose U -bolts (see (Figure 6-272) and position and the steering box on the high
cracked or broken spring leaves. spot. Adjust as outlined in the service manual.
After adjusting, if you notice a bind when the
SCHEDULED MAINTENANCE wheels are turned from full left to full right,
recheck the adjustment. If the adjustment is
Scheduled maintenance for steering and correct, it could indicate a problem within the
suspension involves lubricating all steering steering box, in which case the box would
and suspension parts of the intervals recom- have to be removed and repaired.
mended by the manufacturer. When a vehicle
is lubricated. a thorough visual inspection Steering Lubricants
should also be carried out. This inspection
should take in the daily, routine checks listed Steering lubricants may be divided into three
above as welt as more thorough checks that areas: steering linkage. manual steering
would include checking for: gears, and power steering units. Each area
uses a different lubricant: check the service
Bent tie rods. manual for the recommended type.
Loose tie rod ends.
1. Steering linkage For king pins, drag
Looseness of the drag link at the ball link. tie rod ends, pivot points. shackle
stud sockets and tube clamp bolts. pins. etc., use a good grade of chassis
Also check that the clamp bolts are in grease such as a lithium or Moly base.
the right position and are not interfered
with. 2. Manual steering gears many manual
Loose steering gear mounting bolts. steering gears use S.A.E. 80 GL5 gear oil.
cover retaining bolts. and steering gear although a different lubricant is recom-
lever nut or pinch bolt. Also check the mended by some manufacturers. e.g.. G.M.
steering gear frame mounts for cracks. 3. Power steering systems lubricants for
Excessively worn or loose steering power steering systems vary a great deal.
universal joints. Some of the common ones are:
Excessively loose king pins or wheel S.A.E. 10 Engine oil with API, SD or SE
bearings. Specifications
Loose or missing bolts or rivets on A.T.P. (Automatic Transmission Fluid)
spring hangers. Also check for frame
cracks at hanger mounts. C2 Torque fluid
Type F Automatic Transmission Fluid
Excessive play of articulated machine's
pivot points.

583
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:287

Figure 6-400 shows a typical lubrication chart

for an on-highway truck showing only the
steering and front suspension, Lubricants and
intervals are given in keys.

Note On Grease Gun Use

Pressure guns should be held on fittings until
new grease appears. The appearance of new
grease will assure that all the old con-
taminated grease has been forced out. Ex-
perience has shown that the best distribution
of new lubricant and the best purging of old
lubricant is obtained when approximately
4,000 p.s.i. pressure is applied at the grease
gun nozzle.

LUBRICATION CHART
K-100 SERIES

-I F
wealcara INTERVAt INTERVAL LURRICANT

CAD TILT
-1
TILT PIVOTS et 6 ...,
CL
STRING TINS
lOss twosome% vial
STEERING U JOINTS
%Om ONIoduthes$1 CI. a ------- 10 CAS LIS I CYLINDER ANCHOR TINS

sulooNG Syr Joon CL 6 f *000 StACx ADJUSTERS

12 Da ItoDocsla ustoulya
STEERING GEAR ROA OH WU I oust oust
Checked WO GO
yon sod Wu GO MONT 1$.11E E L BEARINGS
GO OA Istmesud
SIIONT ONE CAUSNAIT CL Grow Mutated
Itsbocus woody, 00
ISps wigs numbest, NINO INN
CL IToo lump sub ods/
ONAG LINN
Mos Moos soh oull CL Siltitgl tautC3tLE wit
CL 41.0. LIAM usO NAT
TIE ROD ENDS
tens Atom sad, WO et CAD TILTING JUIN
NY CANN NW NM
ORRICE TOE ROLE NY Don 000.1011
hor 10000. Wow sod sows 10 2$

R STEERING RESERVOIR
Odes Mud Soul
CI Mud sod Isar
Voduu A 61$1000 NTS
Rau Irolausl$ AU
Durward Iloupull 10
, LueArcafts kr(
ell - DOI Rums Gm* EI
lIG - NU* Gros ISM 001 ow)
Ct. - Como lobe
SO - &Nos Od
INTERVAL kilt GO - Gm 0.I
6 6000 Wu OD 000 $N1 NY - INOSOIN C0000I/ 04
I!
at It 000 IOUs 1200001ml NTS - SuuvANN Turoomoso SN.d
N.S wrechht Trsooutoon F1040 Tvp0 C 2
2S 25 000 OM Da 000 Soil
SI. - Wens Isamu,
A 0000100 tt - Loa Lotsieso I
AR As Reasos4 SG - PaNsuuou Gm* Sack

NOTE Ades 10 ON 10104000 S000100000 Gust No rusouuso000 laboalros Sod Nuo0

uNuus TA. *rose 00ortali 0014 elfeW VI IV ~rod mown sodUcut only

(6.400)
Courtesy ol Kenworth Truck Company

584
6:288 WHEEL MACHINE STEERING AND FRONT SUSPENSION
Front Wheel Bearing Packing and Adjusting REMOVING FRONT WHEEL BEARINGS
Periodic inspection of wheel bearings, as well Before wheel bearings can be inspected or
as regular lubricant changes. are necessary packed, they must be removed. Two views of
for maximum wheel bearing life. The wheel bearings are shown in Figures 6-401
frequency of lubricant changes depends upon and 6-402. Bearing removal involves jacking
individual vehicle operating conditions, the vehicle up so that the wheel clears the
speeds and loads. Under normal conditions, floor, and then removing the wheel and hub as
the following lubrication intervals for wheel an assembly. After the hub cap (dust cap) and
bearings are recommended for on-highway bearing adjusting nut are removed, the wheel
trucks: and hub assembly are slid from the spindle
with care taken not to drag the hub or inner
Grease Lubricated For bearings that bearing cone over the spindle threads.
are lubricated with grease, changes are
recommended whenever the seals are The outer bearing race will fall out as the hub
replaced or brakes are relined or at 25,000 and wheel are removed. The inner race can be
to 30.000 mile intervals. For vehicles easily removed by driving it out with a drift
operating less than 30,000 miles annually, from the outside toward the inside. The
the lubricant should be changed twice a grease seal will be pushed out at the same
year. Wheel bearing grease should meet time. usually without damaging it.
manufacturer's specifications.
Oil Lubricated For bearings lubricated WEAR SLEEVE
with oil, changes are recommended
whenever the seals are replaced or at HUB SEAL
brake reline time, or at least once a year.
Wheel bearing oil should meet manufac-
turer's specifications.

SEE-THROUGH OIL CHECK

INNER BEARING
OUTER BEARING

(6-401)
Courtesy of Ford Motor Company

PACK GREASE BETWEEN

SPRING AND SEAL LIP

BEARINGS SEAL LIP

VENT

SEAL
JOURNAL
LOCK NUT

LOCK WASHER

BEARING
(6-40 2) Courtesy of Ford Motor Company
ADJUSTING NUT

585
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:289

Cleaning and Inspecting Packing and Lubricating

Clean all old grease or oil from the bearings Grease Packed Bearings
and from hub cavities with solvent, kerosene
or diesel fuel oil and a stiff brush. After See the service manual for the correct type of
clean;ng, the bearings shout( be dried with grease to use. Pack the bearings .vith a
compressed air Direct the air across the pressure packer if possible. If a packer is not
bearings- never spin bearings while blowing available. pack the bearings by hand. forcing
them dry Clean the spindle, as well. Always the grease into the cavities between the
dry parts before lubricating them. Grease or rollers and cage from the large end of the
oil will not adhere to a surface which is wet cone. As well cover the ends of the rollers
with solvent and besides, the solvent may freely with grease. Fill the wheel hub with
dilute the lubricant. grease to the inside diameter of the outer
races and also fill the hub grease cup (see the
Inspect bearings for excessive wear. chipped shaded areas in Figure 6-402). Also, apply a
edges and other damage. Slowly roll the film of grease on the bearing spindle to
rollers around the cone to detect any flat or prevent rust from forming behind the inner
rough spots. Replace damaged beatings. If bearing cone.
cups are pitted or cracked, they must be
replaced (See the section on bearings at the Note: Always complete the job of assembl-
beginning of this block.) ing the wheel on the spindle after
packing the hub and bearing to avoid
Also inspect the hub oil seal(s). New hub oil accumulating dust and grit on greased
seals should be installed when there is the surfaces.
slightest indication of leakage. wear, or
damage. An imperfect seal may permit Oil-Lubricated Bearings
bearing lubricant to reach brake linings,
resulting in faulty brake operation and a Lightly coat the bearings with oil. Also wipe a
premature replacement of linings. The recom- film of oil on the bearing spindle to prevent
mended practice is to replace the seal. rust from forming behind the inner bearing
cone. Install the inner bearing and seal, and
carefully install the hub over the spindle. In-
stall the outer bearing and adjust it (see
below). Care should be taken to correctly in-
stall the hub cap gasket because oil leakage
could occur here. Install the cap (the cap and
--,--_ plug should be clean). torquing the cap bolts
evenly.
fr.
Fill the hub with oil to the level indicated on
6
the cap (Figure 6-403). Wait a sufficient time
for the lubricant to find its level. Rotate the
__Ztimaord_..-_ wheel and recheck the lubrication level.
.r-

1 Plug 5 Window Ring

2 Gasket 6 Screw
3 Window Plug 7 Cap Assembly
.." 1-6721 4 Window 1.6107
OIL LEVEL (BEARINGS) OIL LUBRICATED BEARINGS
(6-403;
Courtesy of General Motors Corporation (HUB CAP)

586
6:290 WHEEL MACHINE STEERING AND FRONT SUSPENSION

INSTALLING WHEEL SEALS 1. Single Adjusting Nut

Coat the lip of the seal with grease. On double Tighten the adjusting nut with a 12 inch
hp seals fill the cavity between the lips with wrench. while rotating the wheel, until
grease. Some manufacturers recommend put- there is a slight bind to be sure all bearing
ting a thin layer of non-harJening sealing surfaces are in contact. Then back off ad-
compound on the seal seat. Always install the justing nut one-sixth to one-quarter turn or
seal with the lip pointing inward, or toward the to the nearest locking hole or sufficiently
fluid it will seal. Be careful when installing the to allow the wheel to rotate freely within
hub assembly on the spindle not to damage limits of .001 inch to .010 inch end play.
the oil seal. Lock nut at this position.
ADJUSTING BEARINGS 2. Double Adjusting Nuts

In most cases wheel bearing adjustment in- Tighten inner nut with 12 inch wrench.
volves: while rotating the wheel, until there is a
slight bind so that all bearing surfaces are
1 Tightening the bearing nut while rotating in contact. Then back off inner nut one-
the wheel alternately in both directions. quarter to or.c-third turn to allow the
until a slight bind is felt. Four types of wheel to rotate freely. Install lock washer.
bearing nut arrangements are shown in Tighten jam or outer nut. Final bearing ad-
Figure 6-404. justment should be wtihin .001 inch to .010
inch end play. Lock nut at this position.
2. Backing off the nut a fraction of a turn to
align with the nearest locking hole. Note the following two factors that can in-
terfere with getting a correct bearing ad-
3. Locking the nut. justment:
Below are two examples of adjusting make certain that brake shoes aren't in
procedures for grease or oil lubricated
contact with the drum because you will
bearings taken from Timken service in- get a (else adjustment.
formation.
do not confuse bearing tightness wi.h a
ORE ASE RE TAINER
;140
possible drag of the seal.
BEARINE G
BEARING CUP RAC BEARING
1202 COTTER 1201 RACE
PIN 1216
INNER BEARING BEARING CUP
1211 1217 WASHER
1195
CUTER BEARING
1216 INNER BEARING ADJUSTING NOT
1201
LOCK NUT
3295

GREASE
wASHER RETAINER
1105
IHO
BEARING WASHER
ADA/STNIG NUT 1216 1A043
3113811S
F100-350 SERIES
(DISC) LOCK NUT 12000 Le, AXLE
113041.5 (CENTER POlt1T1
BEARING
RACE
1201 OUTER DINER
BE 12ARING SEARING
16 1201
wog 0 BEARING
1201

RING

GREASE AO2USTING
RETAINER 1101
WO

GREASE
RETAINER
BEARING
RACE
1216 ACOUSTING NUT
351163.5
'COTTER PIN
5000 - 5500 - 6000 - 7000 LS AXLES (6.404)
16000. 18000. 20000 LB. AXLES
Courtesy ot Ford Motor Company
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:291

Checking Wheel Bearings 2. Block and jack the vehicle high enough
so that the wheels clear the ground. A
The discussion on bearing adjustment above good place to block is on the frame lust
assumed that the bearings had been removed behind the rear of the front springs. The
and were adjusted when reinstalled. vehicle can also be raised with a chain
Following is a quick method of checking hoist and suitable rigging or with an
bearings without removing an ?thing: jack up overhead crane.
the front axle until the wheels clear the floor.
Check the bearing play by grasping the tire at Caution: Whatever lifting method is
the top and pulling back and forth, or by using used, make sure that the
a pry bar under the tire. If the bearings are device has adequate lilting
properly adjusted. movement of the brake capacity. Also. use good sound
drum in relation to the backing plate will be blocking like that shown in
barely noticeable and the wheel will turn Figure 6-405.
freely. If the movement is excessive. adjust as
above.

SERVICE REPAIR OF FRONT

SUSPENSION AND STEERING
The job of removing, repairing and installing
the front suspension and steering components
of a wheel vehicle is similar to working on a
crawler undercarriage in that the work is not
highly technical but care must be taken when
handling the heavy parts. Many front suspen-
sion components can be repaired or replaced
without removing the whole suspension
assembly. However, if the suspension requires
a major overhaul, it is best to remove the com-
plete assembly and work on it on the floor.
The suspension service material given here
assumes that a major repair is being un- (6-405) BLOCKING UNDER FRAME
dertaken. Courtesy of Wabco Construction and
Mining Equipment
Removing Front Suspension and Steering
1. It is a good practice to clean the steering
3. Remove the wheels and hubs as an
assembly Take off the hub cap or bearing
and suspension parts outside the shop dust cover to gain access to the bearing
before bringing the vehicle inside to
remove the assembly. If no cleaning retaining nut. Once the bearing retaining
nut and outer bearing have been removed.
equipment is available clean the parts in-
dividually as they are removed.
use a suitable lifting device such as a
wheel jack or forklift to lift the wheelhub
assembly clear.
4. Disconnect the brake lines and cap them.
whether hydraulic or air. If the vehicle has
shocks. disconnecI them at the frame.
Remove the drag link at the Pitman arm.
The stud on the end of the drag link is a
tapered fit into the Pitman ar i. After the
nut has been removed. strike the arm
sharply with a hammer as iiiiicated in
EERING GEAR Figure 6-406. Sometimes another hammer
HOUSING is required as a back up on the opposite
SECTOR side of the arm.
SHAFT ARM

Courtesy of Ford Motor Company

STRIKE HERE FRONT

WITH A HAMMER DRAG LINK
(6-406)

$88
1
6:292 WHEEL MACHINE STEERING AND FRONT SUSPENSION

6. Support the front axle and springs with steering-front suspension overhaul, the
suitable blocking or, even better, with two general practice is to send the springs to
floor jacks. Remove the spring shackle a spring shop for rebuilding. Rebuilding a
pins and lower the spring axle assembly to spring involves replacing all cracked or
the floor. Note: Make a punch mark on broken leaves and rearcing the ser-
the front of the spring pad before viceable leaves. New spring eye bushings
removing the axle. If the axle center is not and a new center bolt are put in. A rebuilt
marked, it could be installed backward spring is virtually as good as a new one.
and the camber could be wrong. Figure 6-407 shows a dismantled assem-
bly.
Repair 01 Front Suspension and Steering
Note the following when installing
1. Once the axle and springs have been springs:
removed and taken out from under the
vehicle, a careful inspection should be (a) Springs must be installed in the
made of the spring hangers and their correct direction: i.e., the center bolt
frame mounts. Tighten any loose bolts and is often off center making the
replace any loose rivets. If the hanger distance from the bolt to the spring
brackets are damaged in any way, they eye longer one-way than the other.
should be replaced. The frame and cross
(b) If a spacer is used between the
members should also be carefully spring and the axle. be sure to insert
checked and any cracks must be repaired
the center bolt head through the hole
by a welder or competent journeyperson.
in the spacer and into its slot in the
2. Remove the springs from the axles at the axle. Similarly. if alignment shims (for
U-bolts. Note the position of shims. spacer caster) are used. Install them in the
blocks, shock brackets and dowel pins so correct direction and in their original
that they can be correctly reinstalled. position. Again, be sure that the cen-
Springs become fatigued and flattened af- ter bolt fits through the hold in the
ter long service. When doing a complete shims and into its axle slot.

REAR HANGER
U-BOLTS

SHACKLE
LINK

FRONT HANGER

BUMPER-10 U-BOLT
SPACER
CENTER 19®
BOLT

SHOCK
EYE BOLT
SPRING ASSEMBLY
LINERS
O
es

SPACER A4479.

(6-407) Courtesy of General Motors Corporation

589

11111111MINIMINIIME
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:293

(c) Tighten U-bolts with a torque wrench procedures.) Figure 6-408 shows a king
to the specified torque listed in the pin being removed with a hammer and
service manuals. drift. In some cases, however, a press may
be required to remove the pin. Check the
3 Repairs to the steering axle consists of king pins by raising the wheel and moving
removing the steering knuckles from the it in and out at the top and bottom. If
axle center and replacing the king pins wheel play is excessive, it is an indication
and bushings. (See the service manual for that the king pins are loose.

-%*
1.,7r

Ott:
itkiA

,-

(6-408) REMOVING THE KING PIN Courtesy of Rockwell Internalioial

Automotive Operations

590
6:294 WHEEL MACHINE STEERING AND FRONT SUSPENSION

4. Small cracks may exist in steering parts. indicator. Use of a dial indicator is
Since these parts are so vital to the safety described below:
of the vehicle, it is a good practice to have
knuckles, spindles, steering arms and axle (a) Set up the dial indicator as shown in
ends X-rayed or magnafluxed for defects. Figure 6-410. This dial indicator has a
Some shops have the policy of magnetic base to attach it to the
automatically magnafluxing or raying spindle. Other dial indicators can be
vital steering parts. Spindles are the most affixed by a clamp.
vulnerable parts for cracking, especially (b) Place the dial indicator plugger on
at the point where they join the knuckle the exposed end of tha knuckle pin
right near the seal surface (Figure 6-409). so its line of action is apprnxima'ely
parallel to the knuckle ;. n , vertu's.
(c) Zero the dial indicator
(d) Using a suitable lever or bloc!: and
lever. lift the knuckle and take the
dial reading.
(e) Repeat the above procedures with
the knuckle in full right and full left
turn positions.
(f) If the clearance is not right, correct it
VULNERABLE
AREA by adding or taking out shims be-
tween the axle and the knuckle.

(6-409)
Courtesy of Rockwell Internalionat
Automotive Operations

If electronic crack detecting equipment is

not available, cracks can sometimes be
spotted in the following way: wash the
spindle, and i- .ding it in one hand strike
it a few light blows with a hammer. If a
crack exists, it will show up as a faint dark
line. This method is not as reliable as a
magnaflux or an X-ray, but it will detect (6.410) ZERo THE DIAL INDICATOR
cracks in many cases.
5. If a king pin is loose fitting in the axle eye,
it must be repaired. The method of repair
is to have the axle bored out at a machine
shop and a steel bushing installed to
return it to its original size. Prelube king
pins (and shackle pins) before installing
them.
When assembling the steering knuckle
and axle, careful attention must be paid to
correctly install the thrust bearing. Also
the knuckle must have the correct
clearance with the axle: there must be
some clearance or end play at the axle
knuckle connection between the yoke and
the pin bore. Most manufacturer's recom-
(6-410) PRY THE KNUCKLE AND TAKE READING
mend measuring the clearance with a dial
Courtesy of Rockwell International
Automotive Operations

591
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:295

STEERING LINKAGE REPAIRS changed by bending the axle. and few shops
are equipped to do this: K.P.I. is built into the
When a complete overhaul is done on axle design; and toe-out on turns is part of
steering, linkage parts (tie rod, tie rod ends. steering arm design. Problems in these three
drag link) should be carefully checked. If areas will require more extensive repair or
worn or faulty. they should be replaced, not replacement of parts.
repaired. Some large tie rods and drag links
have replaceable ends that are rekitted
(Figure 6-411), but the majority are replaced
as an assembly.

(6-411) DRAG LINK ASSEMBLY WITH Courtesy of Kermontl Truck Company

REPLACEABLE ENDS
Turning Angle
Steering Alignment Check the turning angle first. The term tiirn--
Steering is aligned after an overhaul of the ing angle denotes the maximum number of
front end, or as the need arises. Before at- degrees, both left and right. that the front
tempting an alignment. some pre-alignment wheels can be turned from a straight-ahead
checks should first be made. Note that some position Correct setting of this angle is im-
of the pre-alignment checks listed below portant. Too large an angle will permit in-
won't apply to a vehicle that has just had the terference between the tire and chassis.
front end overhauled. which could damage the steering box. Too
small an angle will reduce the truck's
Pre-Alignment Checks (Move the vehicle to maneuverability. A 30" turn, both left and
level ground) right. is standard on most non-driving front
axles.
1. Inflate the tires to the recommended
pressure. Be sure that they are the same Turning angles should be checked whenever
size and have the same number of plies. wheels are aligned or new front axle or
springs are installed. Turning angles are ad-
2. Check for wheel and tire runout. justed by stop screws located either on the
back of the steering knuckle. or on the axle as
3. Check wheel balance. in Figure 6-412.
4. Check that spring U-bolt nuts are tight.
5. Check for loose steering linkage or
knuckle pin bushings or bearings
6. Check the springs for sag or broken
leaves.
7. Check wheel bearing adjustment.
Make any necessary repairs or replacements
before proceeding with the alignment.

Alignment Checks
Easy. accurate steering depends on precise
alignment of the front wheels. Alignment on
heavy duty vehicles generally consists of get- ADimension varies with different size tires. Set stop
screws to provide iS" clearance between fires
ting the correct turning angle. caster and toe- and chassis at extreme turn positions. moue
in. The other alignment factors, camuer. king
pin inclination, and toe-out on turns. are con-
sidered non-adjustable. Camber can only be (6-412) STOP SCREW ADJUSTMENT
Courtesy of General Motors Corporation

592
6:296 WHEEL MACHINE STEERING AND FRONT SUSPENSION

The angles should be set with these factors in (see Figure 6-412). When servicing the springs
mind: and front axle of a vehicle equipped with
caster plates. mark the position of the thick
1. On extreme right or left turn there must be end before removing it to insure correct
a clearance (recommendations vary from reassembly.
1/2 inch to 1 inch) between the tires and
the chassis or drag link. To check caster. the alignment equipment
below is required (instruction will be supplied
2. There must be a minimum of 1/2 inch with the equipment):
clearance between moving steering
linkage and the chassis. Two turntables marked out in degrees
to place underneath the tires.
3. On vehicles with power steering, an ad-
ditionai step must be taken. The internal A portable caster/camber gauge with a
relief valves of integral power steering magnetic head for attaching to the end
gears and the steering gear lever stops of of the spindle. When a caster setting
linkage power-assist systems must be ad- that varies greatly from the specified
justed to cut off the power before the axle figure is found. check for problems in
stops are contacted. Clearance between the front springs or axle. Weak or
the knuckle and stop should be 1/16 to 1/8 broken springs, in particular. can throw
inch when power is cut Adjust for both out caster. Replace defective front end
right and left turns. See service manual for parts before proceeding with the caster
adjusting procedures. check. Do not attempt to corre..:,
severely misaligned caster by using an
4. For good steering performance. the extreme angle caster plate. If it is
steering gear should be centered when necessary to change the caster setting,
the wheels are in a straight-ahead stay within the specifications recom-
position. 11 the gear is centered. it will not mended by the manufacturer.
bottom when the front wheels are at
maximum angle. the steering wheel Toe-In
should have one-third tuft remaining
when the front w heels are at the axle Toe-in misalignment occurs when the wheels
stops. in the straight-ahead position are pointed in-
wards beyond an acceptable amount. (Many
To check steering gear centering, place steering systems are set up to have a slight
the front wheels in a straight-ahead toe-in.) An obvious sign of excessive toe-in is
position. and then disconnect the drag a saw-toothed pattern across the face of the
link at one end. Turn the steering gear to tire which can be felt 1,, running your hand
its center position and try to reconnect the across the tire. (Toe-ou. will gave an opposite
drag link. 11 the drag link can be rein- saw-tooth pattern to toe-in.)
stalled without disturbing the front wheels
or steering gear. the system is satisfac- Measuring Toe-In
torily centered. If the drag link ball stud
does not line up with its mating hole, the The method below is the most common and
system is not centered and corrections the most accurate way of measuring toe-in:
must be made. See the service manual for 1. Raise the front wheels until they clear the
cente ring procedures.
floor.

Caster
2. Using the instrument shown in Figure 6-
413, inscribe a fine line around the ap-
As stated earlier, most trucks have a positive proximate center of each tire.
caster, i.e.. the knuckle pin is tilted to the rear.
3. Lower the vehicle to the floor and turn the
The angle of tilt should not vary more than wheels straight-ahead (Note: Do not take
half a degree between the right and left side.
a toe-in measurement with the front axle
Caster is adjusted by wedge shaped shims
called caster plates located between the jacked up.)
spring and the axle. Caster plates are factory 4. Before taking a toe-in measurement, nor-
installed. For positive caster the thick end of malize the suspension parts by rolling the
the shim faces the rear of the vehicle; for vehicle 12 to 15 feet ahead. This is
negative caster the thick end faces forward necessary because when the vehicle is

593
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:29T

first lowered, the tires grip the floor. done on large mine haulage trucks. Below is
preventing the wheels from returning to the method one manufacture recommends to
their normal operating position. measure toe-in. Refer to Figure 6-414.
5. Measure the distance between these two 1. Position the truck on a hard even surface
scribed lines at the front of the tires and at with the front wheels straight-ahead. Ad-
the rear. The two measurements should be just the front suspension cylinder to the
within allowable tolerances. recommended pressure and piston ex-
posure.
A quicker but less accurate method of
measuring toe-in is to measure the distance 2. Using a plumb-bob and a block (the block
between the tire tread centers or the insides is used to provide an extension of the
of the tires. both at the front and back of the wheel hub surface), establish a point on
tires. the ground from both the front and rear of
the wheel hub. Do this at each front wheel.
Correcting Toe-In
3. Using a chalk line, snap the line on the
Before snaking a toe-in adjustment. the ground between these points. Extend the
wheels must be normalized (see point 4, line out beyond the front and rear of the
above). tire.
Minor toe-in corrections, on vehicles with 4. Drop a plumb-bob from the approximate
straight cross steering tubes, are made by front center of the tire and mark a point.
loosening the clamp bolts and turning the
cross steering tube. The tube and ball sockets 5. Drop a plumb-bob from the approximate
have either right and left hand threads or rear center of tire and mark a point. Do
threads of different pitch. If the cross steering this at both front wheels.
tube has a drop-center design. it generally is 6. Measure the distance between the two
necessary to disconnect the tube and rotate lines at the front of the tires and at the
the ball socket(s). If a major correction is rear. On this particular machine the
required, first check for bent steering levers distance at the front of the tires should be
or a bent cross steering tube. between half to one inch less than the
distance at the rear of the tires. In other
Toe-In On Large Mine Haulage Trucks words. a toe-in of half to one inch is
Toe-in is the only alignment procedure that is
desired; anything over that should be
corrected.

_ , , .._ -, . .

(6-413) Courtesy of Rockwell International

Automotive Operations

594
WHEEL MACHINE STEERING AND FRONT SUSPENSION

PLUMB-SOB

CHALK LINE

T TO MEASURE TO

(6-414)
Courtesy of Wabco Construction
and Mining Company

595
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:299
Wheel Balancing
the rim, for example ten ounces, place five
More attention is paid today than in the past ounces, inside the rim and five ounces
to wheel balancing on heavy duty highway outside the rim. This method will even out
trucks. The reason is that trucks travel faster the weight on the rim.
due to improved roads and tires. At the
present time, very few heavy duty shops have Note: Once the wheel has been balan-
wheel balancing equipment. When a balan- ced. don't forget to readjust the
cing problem occurs. it is handled by a tire wheel bearing and brake.
shop. This situation is changing. though. and
PO doubt in the future wheel balancing equip- Troubleshooting Steering
ment will become as common in heavy duty
shops as it is in automotive ones. In the discussion above. steering was E.:ig: 6. _,
as part of front end overhalii p7ocg!ii01(1
When faced with an assumed wheel balan- More commonly. a vehicle wit: corn,- :1:n a
cing problem, you first should check some shop with what is vaguely ref !feel to as a
other likely possibilities that could be causing steering problem. When inVeSligat -:g a
the problem. Check for: steering problem that has no evident causem.
an out of round tire. it is good diagnostic procedure to begin with
excessive wheel or tire runout that the simplest possible cause. Then progress
could be caused by an improperly through to the more complex causes until the
tightened or mounted wheel problem has been found. Check first for
unequal tire pressures. loose wheel stud nuts.
mud build-up on the inside of the wheel worn steering linkage. worn or dry king pins,
As was mentioned earlier. dynamic wheel loose or worn wheel bearings or a misaligned
balancers are used to determine a wheel's front end assembly. If these are in satisfactory
state of balance. Two types are available, one condition, then isolate the steering gear for
for on-vehicle and one for off-vehicle balan- diagnosis by disconnecting both the drag link
cing Balancers indicate the location of heavy from the Pitman arm end and the steering
spots and in some cases give the amount of column universal joint from the worm shaft.
weight required to balance the wheel. If the General steering gear problems and causes
balancer does not give the weight requ'sed, are listed below:
then a trial and error method is used to find Problem: Hard Steering
the ,orrect amount of balancing weight.
1. Lack of lubricant (tight king pin).
When a wheel balancer is not available. an
unbalanced condition can be detected in the 2. Binding universal joints or slip joint.
following way:
3. Worm bearing or Pitman arm shaft ad-
1. Jack the wheel up so that it clears the justed too tight.
floor.
4. Worn steering gear bearings or bushings.
2. Back off the brake adjustment so that
there is no interference from the brake 5. Worn or damaged worm gear or roller.
shoes. 6. Binding cover boot in cab.
3. Adjust the wheel bearing so that the
wheel will turn freely by itself. Problem: Wandering or Weaving
4. Spin the wheel and allow it to come to 1. Excessive Pitman arm shaft backlash.
rest. Chalk the tire at the bottom. 2. Loose steering gear mounting bolts.
5. Repeat spinning the wheel. If the chalk 3. Worn universal joints or slip joint spines.
mark continually appears at the bottom. a
heavy spot is indicated at this point. 4. Loose spring U-bolts.
6. If wheel weights are at hand, you can get 5. Worn shackle pins and bushings.
a reasonably close wheel balance setting.
Select weights by trial and error placing 6. Worn king pins.
them on the rim 160 from the heavy spot 7. Excessive toe-in or toe-out.
until the wheel has no tendency to stop at
any given spot. When attaching weights to 8. Worn tie rod ends.
6:300 WHEEL MACHINE STEERING AND FRONT SUSPENSION

Articulated Steering Repair To remove a typical manual steering box:

The steering repair on articulated machines 1. Turn the wheels to a straight-ahead
that you will most likely be involved in at this position.
level of training is servicing the center or
hinge pin. Hydraulic repairs on articulated 2. Disconnect the coupling on the steering
steering will be taken in future training. shaf' lust above the gear box. Mark the
Repair of the hinge pin includes separating coupling for reference with reassembling.
he two frame halves. cleaning and inspecting The yoke may have a master spline but it
the hinge pin(s). bearings and seals, and is still a good idea to make a marking.
replacing the worn or damaged parts. Also. 3. Remove the Pitman arm; this generally
the pin yokes on the frames should be requires the use of a puller. Depending on
checked for cracks. If any are found, they the vehicle, it may be easier to first
should be welded by a welder or jouneyper- remove the drag link and then remove the
son. Pitman arm after the box is out.
Note: Separating an articulated frame is a 4. Remove the mounting bolts and lift the
major job and requires correct lifting box clear of the frame. Figure 6-415 shows
and blocking equipment. Refer to the a typical example of manual steering
service manual and obtain the help of mounting for a cab-over-engine truck:
a journeyperson.

Manual Steering Gear Repairs.

Steering boxes must be removed to be
repaired. Most steering boxes have a coupling
on the worm gear shaft by which the steering
box can be aisconnected from the steering
shaft. Following is a summary of the steps
needed to remove a steering box. Although
the steps sound quite simple. in some cases.
steering boxes can be difficult to get out.

UNIVERSAL
COUPLING

PITMAN ARM DRAG LINK

Courtesy of Kenwoffh 'Cluck Company

(6-415)

597
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:301

Manual Steering Box Repair and Adjustment 6. Pre-lube all parts and reassemble.
1 In keeping with good repair practices. 7. There are two adjustments to be made on
clean the exterior of the gear box with a gear box:
solvent before disassembling it. white
cleaning the housing. inspect for cracks. (a) worm shaft preload adjusted by
shims
2. Drain the oil. sector shaft backlash adjusted by
(b)
3. Disassemble as described in the service adjusting screw.
manual. Where applicable keep shim The worm shaft bearing preload is always
packs together as they will be needed for done first and the sector shaft backlash
adjustment on reassembly.
second. Again follow the procedure in the
4. Wash all internal parts and carefully in- service manual. In the 'exploded view of
spect the gears for damage and wear. the steering box in Figu 3 6-416 note the
shims (5) for worm shaft bearing preload
5 Make parts list keeping in mind that these adjustment and also the adjusting screw
boxes work under heavy loads and (21) for sector backlash adjustment.
therefore should automatically have the
bearings, seals and cover gaskets 8. Fill the box with the correct type and
replaced. amount of lubricant.
2
1
I 9. Before reinstalling the steering box,
9 4 carefully check the frame mount. If any
cracks are found they should be repaired.
Since mounting bolts are subjected to a
terrific load and are susceptible to
6 breaking after a tong service life, it is a
good idea to replace them on rein-
stallation. The replacement bolt should be
of equal grade to the originals. Where cot-
-7 8
ter pins are used, make sure they are in-
serted after tightening.
9
el 10

2928
(6-416) EXPLODED VIEW OF
STEERING GEAR BOX 20
1273, 1427
24 0 co
25
26
I WORM COVER CAPSCREW 16 CROSS SHAFT BUSHING
2 WORM SHAFT OIL SEAL 17 PITMAN ARM
3 BREATHER 18 OIL DRAIN PLUG
4 WORM COVER 19 EXPANSION PLUG
5 WORM COVER SHIMS 20 CROSS SHAFT ASSEMBLY
6 WORM BEARING CUP 21 ADJUSTING SCREW
7 WORM BEARING CONE 22 ADJUSTING SCREW THRUST WASHER
8 WORM & SHAFT ASSEMBLY 23 ADJUSTING SCREW RETAINER
9 WORM BEARING CONE 24 CROSS SHAFT BUSHING
10 WORM BEARING CUP 25 CROSS SHAFT COVER GASKET
11 HOUSING 26 CROSS SHAFT COVER
12 OIL FILL PLUG 27 ADJUSTING SCREW LOCKNUT
13 PITMAN ARM PINCH BOLT 28 CROSS SHAFT COVER CAPSCREW
14 PITMAN ARM PINCH BOLT NUT 29 CROSS SHAFT COVER 0-RING
15 CROSS SHAFT OIL SEAL Courtesy of keewortu Truck Co.
6:302 WHEEL MACHINE STEERING AND FRONT SUSPENSION

QUESTIONS WHEEL STEERING 9. If a spring has several cracked leaves.

MAINTENANCE AND REPAIR does good repair practice dictate that
the spring must be replaced?
1. What on-the-machine adjustment is
made to manual steering boxes? 10. Where is the most likely place to check
for a spindle crack?
(a) sector backlash, worm shaft preload
(b) worm shaft preload 11. If a king pin fits loosely in the axle eye.
the recommended practice is to:
(c) sector backlash
(d) adjustment of Pitman arm-drag link (a) replace the axle
connection (b) bore and re-bush the axle to its
original size
2. List the three areas that steering
lubrication is divided into. (c) heat the axle and shrink it
(d) get a larger king pin
3. Referring to Figure 6-400, what type of
lubrication is used on tie rod ends, and 12 is necessary at the axle-
how frequent, under normal operating knuckle connection between the yoke
conditions, should they be lubricated? and the pin bore. A is
used to measure it.
4. Wheel bearings are lubricated with
either or 13. Besides setting the stop screws for
maximum turning angle, the only other
5. When packing wheel bearings with adjustments that are possible on a heavy
grease the hub between the two bearing duty truck front axle are
cups:
(a) king pin inclination and camber
(a) should be filled with grease
(b) caster and camber
(b) should not have any grease in it
(c) toe-out on turns and We-in
(c) should be filled with oil
(d) toe-in and caster
(d) should be one-quarter filled with
grease 14. The most accurate method of adjusting a
6. A wheel bearing when properly adjusted front wheel bearing is to:
should allow for: (i) tighten the adjusting nut with a
(a) .001" to .010" preload torque wrench to specification
(b) .0" preload (b) tighten the nut until the wheel
drags, and then back off the nut a
(c) .001" to .010" end play little
(d) .001" to .020" end play (c) make the nut finger tight
7. when installing a wheel seal, the lip of 15. On a vehicle equipped with a solid I-
the seal is placed with the lip pointing: beam front axle, an incorrect camber
(a) inward could be caused by:
(b) outward (a) a bent spindle
(c) either way; lip direction is not (b) a bent axle
critical (c) both of the above
8. A good service practice when brake or
hydraulic lines are disconnected is to: 16. To check for worn king pins on a solid
(a) tie the lines up out of the way front axle:
(b) cover the lines with a rag (a) move the wheel in and out at the top
(c) cap the ends of the lines and bottom
(d) remove the lines (b) move the wheel in and out at the
front and rear
(c) move the wheel in and out on the
centerline of the spindle

599
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:303
17. If a front wheel on a loaded truck has ex- 25. When installing a rebuilt steering box, it
cessive negative camber, the: is a recommended Practice with moun-
ting bolts to:
(a) outer wheel bearing has the
greatest load (a) carefully check the bolts for cracks
(b) inner wheel bearing has the and replace the faulty ones
greatest load (b) reuse the bolts as they almost never
(c) both wheel bearings are loaded the get damaged
same (c) replace all the bolts with new ones
of equal grade to the originals
18. If toe-out on turns is incorrect, the fault
is:

(a) an incorrect caster angle

(b) incorrect toe-in
(c) an incorrect camber angle
(d) a bent steering arm(s)
19. If toe-in on a vehicle is incorrect, an ob-
vious sign would be:
(a) a wavy tire tread pattern
(b) pulling to the left
(c) a saw toothed pattern across the tire
face
(d) all the above would indicate a toe-in
problem
20. A vehicle has been jacked to work on the
front end and is lowered to the ground.
What must be done before a toe-in
measurement can be taken?
21. Vehicles with radial tires should have the
toe-in set at:
(a) 1/16" toe-in
(b) 1/8" toe-in
(c) 1/16" toe-out
(d) 0" toe-in
22. Tires that are unbalanced and have been
used for a long time will have:
(a) feathered edges
(b) cupping
(c) tread worn off on the inside or out-
side of the tire
(d) a wavy tread surface
23. When faced with what looks like an un-
balanced wheel, what checks should be
made first that could be causing the un-
balanced wheel symptoms.
24. What would be the effect on steering of
Worn shackle pins and bushings, king
pins, or tie rod ends?

600
6:304 WHEEL MACHINE STEERING AND FRONT SUSPENSION

ANSWERS -- WHEEL VEHICLE STEERING 24. (b) steering box

1. (c) linear motion of the linkage 25. The hydrostatic system has no
mechanical connection between the
2. (d) tie rod steering wheel and the vehicle's wheel.
3. (d) Pitman arm to the steering control 26. Depending on which way the steering
arm wheel is turned, the steering unit directs
4. - manual steering oil to either the right or left steering
cylinder which supplies the force to turn
- power steering the wheels.
- emergency steering
27. False.
5. - worm and roller
28. To provide enough power to safely bring
- recirculating ball the vehicle to a stop. The three
-cam and lever emergency systems are: orbital control,
electric motor driven pump, hydraulic ac-
6. False cumulator.
7. .... hourglass. ... straight. 29. Steering geometry refers to the angular
8. (c) a lever and stud arrangement in- relationship between the front wheels.
stead of gear steering linkage and frame.

9. To allow the spring to lengthen and shor- 30. (c) forward or backward tilt of the king
ten as it flexes. pin

10. .... grease MOP- 31. positive caster.

11. (b) center bolt. 32. True.

12. (c) control spring oscillations 33. (b) an angle in the axle that tilts the top
of the wheels outward.
13. True.
34. True.
14. (b) The bottom of the axle eye
35. (b) positive camber
15. The flange on the wheel spindle.
36. (a) cannot be adjusted without bending
16. Yes, two fittings. One each at the upper the axle
and lower pin bosses.
37. (d) adjusting the length of the tie rod
17. Grader wheels must tilt as well as turn.
38. True.
18. ... hydraulic tilt cylinder ... bring the steering pivot axis nearer
39. (d)
19. (d) all of the above are correct. the center of the tire-road contact area
20. - power-assist 40. ... unbalanced ....
- full power 41. .... heavy spots. ... vibrates....
- hydrostatic
42. Kinetic unbalance that causes an up and
21. The booster can be either: down wheel motion or wheel tramp.
(a) mounted to the front axle with the 43. (c) 180 from the heavy spot.
piston rod clamped to the tie rod
(b) mounted within the drag link along
with the control valve
22. (d) steering linkage (drag link)
23. .... integral power steering ...
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:305

ANSWERS WHEEL STEERING 24. Wandering or weaving steering.

MAINTENANCE AND REPAIR
25. (c) replace all the bolts with new ones
1. (c) sector backlash of equal grade to the originals.
2. steering linkage
manual steering gears
power steering systems
3. Chassis lube grease every 6.000 miles or
10.000 kilometers.
4. ...grease or oil.
5. (d) should be one-quarter filled with
grease
6. (c) .001" to .010" end play
7. (a) inward
8. (c) cap the ends of the lines
9. No. Springs can be rebuilt. A rebuilt
spring can be almost as good as a new
one. The cost is the main factor.
10. Where the spindle joins the knuckle
flange near the seal surface.
11. (b) bore and rebush the axle to its
original size
12. End play .... A dial indicator ...
13. (d) toe-in and caster
14. (b) tighten the nut until the wheel
drags. and then back off the nut a
little

15. (c) both of the above

16. (a) move the wheel in and out at the top
and bottom
17. (a) outer wheel bearing has the
greatest load
18. (d) a bent steering arm(s)
19. (c) a saw toothed pattern across the lire
face
20. Normalize the wheels by moving the
vehicle forward and backward 10 to 15
feet.
21. (d) 0" toe-in
22. (d) a wavy tread surface
23. out of round tire
excessive wheel run-out
mud accumulation on the inside of the
wheel
6:306 WHEEL MACHINE STEERING AND FRONT SUSPENSION

TASKS WHEEL MACHINE STEERING if the vehicle has hydraulic

AND FRONT SUSPENSION steering, disconnect and cap the
hydraulic lines connected to the
ROUTINE MAINTENANCE steering axle.
CHECKS if the vehicle has hydraulic brakes,
1. Check for and tighten all loose suspen- disconnect and cap the hydraulic
sion mountings. Retorque U-bolts. Check lines connected to the steering
for cracked or broken spring leaves. axle. If the vehicle has an oil over
Check all steering knuckles and linkages oil brake system, bleed down the
for worn or bent parts. Check shack le pins pressure before removing the
and bushings and king pins for wear. lines.
Check the frame, frame brackets. cross
members and hangers for cracks and (b) Clean. disassemble (where ap-
loose rivets. If the vehicle has hydraulic plicable). inspect and decide if the
steering, check the cylinders and lines for following parts are serviceable or if
leaks or damage. Do any minor repairs: they must be repaired or replaced:
report any major repairs needed. springs, spring shackles. king pins,
tie rod ends, drag links, pivot end
SCHEDULED MAINTENANCE CHECK bushings, related linkages hydraulic
lines and hoses. Write a parts list.
1. Follow the service manual scheduled Repair or replace any parts that are
maintenance procedures for v 'lel not serviceable.
vehicle steering and suspension Lk. ii
(c) Check the frame cross members,
elude the following: frame brackets, and spring hangers
(a) Remove the wheel assembly. clean for wear. cracks, loose bolts or rivets.
and repack the wheel bearings, Make the necessary repairs or
replace seals and reinstall and adjust replacements.
the bearings to manufacturer's (d) Prelubricate. and reassemble the
specifications. suspension components.
(b) Move the vehicle to a level floor area (e) Install the steering axle, suspension
and using what alignment tools and components, and brake lines (if ap-
equipment are available, check and plicable). Lower the vehicle:
adjust the wheel alignment.
if the vehicle has hydro-air
(c) If the vehicle has hydro-air suspen- suspension. under the supervision
sion. check for any signs of leaks or of a journeyperson. charge the
damage. and retorque mounting cylinders to the specified pressure
bolts. With the assistance of a jour - and suspension height.
neyperson, check for proper piston
extension and pressure, and adjust if if the vehicle has hydraulic
needed.
steering, top up the reservoir with
the correct type and amount of oil.
SERVICE REPAIR
Start the engine, turn the wheels
full left and then full right to purge
1. Jack a loader, truck (on-highway or off- the air. Recheck the reservoir
highway), or grader. and block it securely making sure that there are no
at a height that permits removal of the leaks.
steering and suspension components. if the vehicle has hydraulic brakes,
2. Using the correct tools, lifting equipment top up the reservoir with the
and procedures outlined in the service correct type and amount of fluid.
manual: Bleed the system at the wheels to
purge the air. Recheck the reser-
(a) Clean and remove the steering axle, voir level. topping up if necessary.
related steering components. and and test the brakes.
brake lines (if applicable).
if the vehicle has hydro-aa
suspension, bleed down the gas
charge before removing the
suspension cylinders.
603
 WHEEL MACHINE STEERING AND FRONT SUSPENSION 6:307

(I) Move the vehicle to a level floor area

and. using what tools and equipment
are available. align the suspension to
obtain correct caster and toe-in set-
tings. Recheck the complete suspen-
sion to ensure all components are
secure and locking devices are in-
stalled. Lubricate all components
where required.
3. Using the correct tools. and procedures
outlined in the service manuals:
(a) Remove a wheel machine manual
steering box.
(b) Clean. disassemble, inspect the
gears and bearings for wear and
damage. Write a parts list, and repair
or replace any bearings or gears that
are not serviceable.
(c) Preiubricate, reassemble the gears
and bearings. and make adjustments.
Fill the housing with the correct type
and amount of lubricant.
(d) Check the frame mounting for cracks
or damage and make any necessary
repairs.
(e) Reinstall the steering box, ensuring
that all components are secure and
locking devices are installed.
(f) Road test the vehicle to check
steering response and handling and
make any final on-vehicle ad-
justments.

604
 BLOCK

Working Attachments

605
 WORKING ATTACHMENTS 6:309

DEFINITION
Working attachments are the implements that
do a machine's work. Several types of im.
plements can be used on the same machine.
74..r example, the bucket on a wheel loader
can be removed and replaced with log forks.
This section discusses the working at-
tachments available for common heavy duty
mac hines.

CRAWLER DOZERS
A number of blades are available for dozers,
each suited to a different type of job. Four
common ones are shown in Figure 6.417.
Universal and cushion blades are generally ANGLE BLADE FOR PIONEERING, BACK-
only used on large machines. Specialty at- FILLING. WINDROWING. THIS MULTI-PURPOSE
tachments are also available for dozers such TOOL ANGLES 25° TO EITHER SIDE, GREATER
as the wood chip bucket in Figure 6.418 and MOLDBOARD CURVATURE GIVES MORE
the land clearing rake in Figure 6-419. ROLLING ACTION.
(6-417)

4
1.

STRAIGHT BLADE FOR GENERAL DOZING CUSHION BLADE FOR PUSH SCRAPERS.
WHERE MATERIAL DRIFTED OVER A SHORT TO SHOCK ABSORBING FEATURE PERMITS EASY,
MEDIUM PASS. (6-417) ON.THE-GO CONTACT. BLADE CAN ALSO BE
USED FOR CLEAN-UP AND GENERAL WORK,
(6-417)
Courtesy of Caterpillar Tractor Co.
When selecting a blade. tractor size and the
type of material that the dozer will cut and
move must be considered. The weight and
horsepower output of a tractor determine the
,
blades ability to bulldoze materials. An in-
i...t.i
k'i."::.,,..- .,...._.6,
dication of a blade's ability to penetrate and
obtain a blade load is horsepower per foot of
, ....;22./.....±.1., cutting edge (1-1P/It). The higher the HP /ft.. the
0 ,0: 4, 0_ 4,) more aggressive the blade. Similarly, an in-
dication of a blades potential to push material
is horsepower per loose cubic yard (HP/LCY).
The higher the HP/LOP. the better and faster
the Wade can push material.
UNIVERSAL BLADE MOVES LARGE VOLUME
LOADS OVER LONG DISTANCES BLADE DESIGN Below are characteristics of materials that in-
DIRECTS MATERIAL FORWARD AND TOWARD fluences the ease or difficulty with which they
THE CENTER IN A CUPPING ACTION. can be dozed,
(6-417)

606
6:310 WORKING ATTACHMENTS

Material Size and Shape The larger the in-

dividual particle size of the material, the more
difficult it is for the blade's cutting edge to
penetrate it. The shape of the material is im-
portant in moving the material: material par-
ticles with sharp edges resist the natural
rolling action of a dozer blade. and therefore
require more horsepower to move than
material with rounded edges.
Material State (i.e., how tightly is it Clearing Rakes remove trees. rocks. and stumps.
packed) Well graded or packed material is pile brush and generally prepare land for replant-
generally harder to doze than loose packed ing. Rakes are made for all sizes of crawlers.
material.
Material Water Content Low moisture con- ""
tent usually increases the bond between par-
ticles. making the material difficult to cut.
High moisture content makes the material
hea y and hard to push. Optimum moisture
content reduces dust and offers the best con-
dition for dozing ease and operator comfort.

4ou
(6-419)
Wood Chip Blades handle
volume loads. Bowl-type and Courtesy of Caterpillar Tractor Co.
U-type are available.

:44

. h Vt3 rZt° Pd:fo

Wood Chip Bowls feature high sidewails to move

large volumes of light materials over long distan-
ces ... up to 65 cu. yd. (50 m3) heaped capacities.
(6-418)
Courtesy of Caterpillar Trackg Co

607
 WORKING ATTACHMENTS 6:311

Crawler Blades roller frame in this example. This frame and

blade are raised and lowered by a hydraulic
Crawler blades are made of heat treated. high cylinder (25), and hydraulic tilt struts (27, 15)
tension strength steel and are constructed in tilt the blade. Other machines have different
box section. Replaceable hardened steel cut- tilt arrangements: some have only one tilt
ting edges are bolted to the bottom edge of cylinder, while others have mechanical tilt
the blade as are replaceable corner bits to the struts. Two other points to note in the blade
lower outside corners. Blades are raised and mounting in Figure 6-420 are: the blade is
lowered by one. or more commonly two. mounted at its center on a ball stud (18)
hydraulic cylinders.
assembly which allows the blade to swivel.
Blades can be mounted either on push beams. Thrust channels (10) at each side of the C.
or on a C-frame as in Figure 6 -420. The C- frame are attached to the blade ends. They
frame is more common. The ends of the C- are adjustable in length permitting the Wade
frame are attached to trunnions on the track to be angled left or right, or held in a straight-
ahead position.

::>..)

GREASE FITTING
41.4 12
12 14 21

TRUNNION

CARRIAGE BALL
t

'NO 12

13
IS

1 Bolts 10 Thrust Channels 19 Ball Sockets

2 Lockwashers 11 Bolts 20 Lockwashers
3 Caps 12 Caps 21 Bolts
4 Shims 13 Shims 22 Bolt
5 CFrame 14 Bolts 23 Cap
6 Bobs 15 Tilt Strut Cylinder 24 Shims
7 Lockwashers 16 Angle Blade 25 Blade Cylinder
8 Caps 17 Nuts 26 Bolts
9 Shims 18 Ball Stud 27 Tilt Jack
(6-420) Courtesy of Caterpillar Tractor Co

.1 f sob
 6:312 WORKING ATTACHMENTS

Crawler Altachmersto
.4 variety of rear-mounted attachments are
also available for crawler dozers. Winches are
often mounted on the rear of dozers for win-
ching or towing (Figure 6-421). (Winches are
dealt with in detail in Block 9.) Scarifiers or
rippers can also be mounted on the rear of a
dozer. their purpose to loosen the ground for
easier dozing (Figure 6-422).
MIMIMINN

a
4,- L
-
A' V

(6-421) TRACTOR-MOUNTED WINCH Courtesy of Caterpillar Tractor Co.

1
,
......... .
..

i.

SINGLE-SHANK ADJUSTABLE RIPPER D7 MULTISHANK RIPPER RIPPER-SCARIFIERS

(6-422) Courtesy of Caterpillar Tractor Co.

609
 WORKING ATTACHMENTS 6:313

Figure 6-423 shows a detail of a ripper. A rip-

per consists of three basic parts: a shank,
wear shroud. and tooth or point. Both the
tooth and the shroud are replaceable wear
parts.

Ripper Nomenclature Guide

ATTACHMENT
PIN HOLES

SHANK
CENTER LINE

SHANK

SHROUD WCKPIN .............- SHROUD

EAR RECESSESS
.4r____..---- RIPPER NOSE
..............-- NOSE FLATS

POINT BUSHING

POINT

POINT PIN

RAMP

(6-423) Courlesy 0 Esco Corporation

610
6:314 WORKING ATTACHMENTS

Crawlers working the logging industry use

special attachments. e.g.. skidding grapples
(Figure 6-424), directional felling siears
(Figure 6-425) and a winch arch (Figure 6-
426).

kali,'
..

Hydraulic Skidding grapples

(6-424) Courtesy of Caterpillar Tractor Co

Directional telling shears cut

..- trees up to 30" (762 mm)
diameter at ground level.

SOO..'- .":
6 ./
Trees can be felled with butt
ends aligned to aid skidding.

..) ! r
et

(6 -425) Courtesy of Caterpiiiar Tractor Co.

integral arch Protects the

winch case. reduces ground
disturbance and helps keep
togs clean when cable
sl. idding.
(6-426)
Courtesy of Caterpillar Tractor Co.

. 611
 WORKING ATTACHMENTS 6:315

CRAWLER LOADERS
Crawler loaders are similar to crawler dozers
except that they use a bucket instead of a
blade. The loader bucket. lift arms and cylin-
ders are attached on each side of the machine
to a loader tower (Figure 6-427). The lower is
made of plates which are attached to or are
part of the main frame. Various buckets are
available to meet different working
requirements.
LOADER TOWER

LIFT ARMS
CYLINDER

PLATES

Courtesy of Caterpillar Tractor Co

(6-427)
A combination quite often used on crawler
loaders is to have a bucket in front and a
backhoe on the rear (Figure 6-428). This com-
bination gives a very versatile machine.

;-- -,a4.,...e5a4.4k

,... 404

(6-428) Courtesy of Caterpillar Tractor Co.

612
6:316 WORKING ATTACHMENTS

WHEEL LOADERS
Various types of buckets are available for
wheel loaders. General purpose buckets and
rock buckets (Figure 6-429) are the most com-
mon. Some specialty buckets are a side dump
bucket (Figure 6-430), a multi-purpose bucket
(Figure 6-430), and a bucket that could be
used for such materials as chips or snow
(Figure 6-431).

"NA

Y. t.e.

GENERAL PURPOSE BUCKET (6.429) ROCK BUCKET

Courtesy of Caterpillar Tractor Co.

:""e-"e".".: -** "

MULTI-PURPOSE BUCKET
17'
Can load and strip top
soil. The bucket clamps
hydraulically to grip logs.
pipes and other hard to
grasp material.
(6.430)
Courtesy of Caterpillar Tractor Co
SIDE DUMP BUCKET
Dumps forward or to the
left. For close quarter work.
(6-430)

(6-431) SNOW. CHIP BUCKET

Courtesy of Caterpillar Tractor Co

4 613
 WORKING ATTACHMENTS 6:317

Buckets, like blades, also need protection on

their lower edge and corners. Common parts
used to protect buckets are cutting edges.
wear strips, and bucket teeth. All of these
parts are replaceable. Figure 6-433 and 6-434
give detailed views of bucket teeth, wear
plates and cutting edges.

BUCKET WITH CUTTING EDGE AND WEAR STRIP BUCKET WITH REPLACEABLE TEETH. ALSO
BOLTED TO THE LOWER EDGE. ALSO CORNER HAVE REPLACEABLE WEAR PLATES UN-
BITS ARE ATTACHED TO THE LOWER OUTSIDE DERNEATH FRONT EDGE.
CORNERS. Courtesy of Caterpillar Tractor Co (G-432) Courtesy of Caterpillar Tractor Co.

STANDARD ABRASION TIP

PROT CTOR

OPTIONAL LONG TIP

OPTIONAL SHORT TIP KUSH MOUNTED
FOR MAXIMUM
FOR HIGHER IMPACT ADAPTER
PENETRATION (6-433) CONDITIONS
Counesy of Caterpillar Tractor Co

WEAR PLATE

SIDE PIN
4 ADAPTER COVER
CUTTING EDGE j
SEGMENT ABRASION TIP
(6.434)
Courtesy of Caterpillar Tractor Co

614
6:318 WORKING ATTACHMENTS

Other wheel loader working attachments are

shown in Figure 6-435. Wheel loaders with log
forks are very common in the forest industry
(Figure 6-436). The forks have replaceable
tips allowing the working length of the fork to
be restored.

(6-435)
BUNCHING SHEARS FALLS AND BUNCHES
SMALL TO MEDIUM SIZE TREES

(6-435)
QUICK COUPLERS PERMIT QUICK SWITCHES
OF WORKING ATTACHMENTS

(6-435)
LOW PROFILE FORKS-HANDLE TREE LENGTH
PULPWOOD
(6.435)
DIRECTIONAL FELLING' SHEARS CUTS TREES
UP TO 30 INCHES THICK

Counesy of Caterpillar 'hector Co

(6-435) LUMBER FORKS

L
(6-435) LOG FORKS

,"114V,E

1.4

_.../111111S

(6-436) Counesy of Catorpiliar, Tractor Co.

615
 WORKING ATTACHMENTS 6:319

HYDRAULIC EXCAVATOR
Hydraulic excavators are built primarily for
digging; a typical one rigged for digging is
shown in Figure 6-437. Many shapes and sizes
of buckets or dippers are available for ex-
cavators. Note in Figure 6-437 the different
hydraulic cylinders that are used to operate
the dipper. Figure 6-438 shows a more DIG WRIST
detailed view of the type of hydraulic cylinder CYLINDER CYLINDER
that is found on excavators.

(6-437)

DIPPER

Courtesy or Bucyrus Erie Co.

EXTEND RETRACT RETAINER PLATE

4.'.____
! CYLINIER HOUSING

.7. 111

ROD WIPER

PISTON USING

GUIDE RING GLAND ROO SEAL

SEALING RINGS

Counesy of Bucyrus Erne Co

CYLINDER ROO

(6-438)

616
6:320 WORKING ATTACHMENTS

Excavator dippers. like loader buckets and

dozer blades, also need protection. In Figure
6-439 note the dipper parts on the digging
edge and corners. Two types of sidecutters
are shown: the right hand side cutter is a
general purpose blade and the left hand side
cutter is a kith. (These and two other types of
sidecutters are compared in Figure 6-440.)
The bucket teeth consist of adapter and a
tooth point. The adapter is either pinned or
welded to the bucket lip. and the tooth point IS
pinned to the adapter.

LUGS
TOP BEAM

CLOSED
LIFTWG
RING

RUNNER
FRONT BEAM

BACK & BOTTOM

PLATE

LEFT
HAND
SIDE OF
BUCKET
R1GHTHAND
BLADE TYPE
S1DECUTTER
BODY (Geo. Purpose)

SIDE
REINFORCING
PLATE TOOTH
SPOOL & WEDGE

SIDECUTT ER
PLOW BOLT.
LOC KWASHER POINT
& HEX NUT PIN & LOCK

LIP

TOOTH HORN TOOTH

POINTS

LEFrHAND
TOOTHTYPE
SIDECIITTER ADAPTER

LEFT HAND IS LEFT SIDE AS VIEWED BY OPERATOR.

(6-439) Counesy of Esco Corporation

617
 WORKING ATTACHMENTS 6:321

TOOTH TYPE

COMBINATION

(6-440) SIDECUTTERS
Courtesy of Caterpillar 'tractor Co.
Although hydraulic excavators are used
mainly for digging, optional working at-
tachments are available for them. Some are
shown in Figure 6-441.

Quick Coupling Devices Bunching Shears Ditch Forming Bucket Ditch Cleaning Bucket
For quickly changing For falling and
working attachments bunching trees
(6-441)

Orange-Peel Grapples Heel Booms

Handling stacked or randomly With main boom. slick.
piled shortwood. live heeling rack and grapple
for handling logs
(6-441)
Courtesy of Caterpillar Tractor Co

618
6:322 WORKING ATTACHMENTS

CRAWLER SHOVELS Shovel buckets or dippers are generally much

larger than excavator and backhoe dippers.
Crawler shovels. as was mentioned earlier The side of a particular shovel dipper will
(see Figure 9-30), can be converted to cranes, depend on the machine's size and on the type
drag lines, clamshelts. However, only shovel of material being dug. Another difference be-
buckets are discussed here. tween shovel and excavator dippers is the
shovel dipper has a hinged door on the bot-
tom for dumping. A typical shovel dipper is
shown in Figure 6-442.
The dumping door on a shovel has a trip
mechanism to release it. The latch bar that is
pulled to release the door requires daily
lubrication, at least once each shift. A door
snubber assembly, located between the dip-
per stick and the dipper, prevents the dipper
door from damage by slamming shut too
rapidly. A snubber is shown in detail in Figure
6-443. It consists of a set of friction discs held
in contact by an adjustable spring tension
bolt. If dipper door slamming becomes a
problem. the pressure on the friction discs
can be increased by the adjusting nut.

HOIST
CABLES

EQUALIZER
ASSEMBLY

TYPICAL
SNUBBER REPLACEABLE
DIPPER ASSEMBLY DIPPER TEETH
STICK
TYPICAL
DIPPER

DIPPER
TRIP
LEVER
PITCH
BRACE
CABLE
TO DIPPER
TRIP MOTOR DIPPER
(6-442)
LATCH
LATCH BAR
Courtesy of Harnischfeger Corporation P&H

619
 WORKING ATTACHMENTS 6:323

GREASE FITTINGS Figure 6-444 shows a shovel tooth and adap-

ter. It is important that missing dipper teeth be
replaced immediately because operating a
, SNUBBER
PIN
dipper without a tooth will destroy the adap-
ter. Replacing an adapter. which is often
FRICTION welded to the dipper. is a much bigger job
DISC than replacing the tooth.
Adapter

Pin and Pin Lock-4.

SNUBBER SPRING
PIN
WASHER

COLLAR
\
,

ADJUSTING
NUT
i_.._.._1 Point

SNUBBER ARM
THRUST 1111
COLLAR .,
CONICAL POINT (6-444)
WELD-ON ADAPTER
bi.

'
GREASE FITTINGS
-.......
SNUBBER
PIN
Courtesy of Esco Corporation

HYDRAULIC CRANES
Many hydraulic cranes use hydraulic
telescopic booms such as the one shown in
Figure 6-445. The boom is constructed of
N........"..
several sections (two, three or four). each sec-
2247
tion having a hydraulic cylinder. Hydraulic
(6-443) TYPICAL DIPPER DOOR SNUBBER lines are all internal. The boom can be ex-
Courtesy of Harnischfeger Corporation P&H panded or retracted as desired, and in its
retracted positions all the sections fit inside of
one another like a telescope. The cable from
the winch passes over the top of the boom.
ROOM POINT SECTION

SECOND INTERMEDIATE SECTIOK

BOOM SECTION SLIDE PADS

CYLINDER LOCK VALVE

500M SECTION SLIDE PADS FIRST INTERMEDIATE SECTION

PAO RETAINER
FIRST INTERMEDIATE
TELESCOPING CYLINDER

SECOND INTERMEDIATE
TELESCOPING CYLINDER

TRUNNION MOUNT
FOR TELESCOPING CYLINDER

LOWER BOOM SECTION

CYLINDER LOCK VALVE

(6-445) TELESCOPIC BOOM
Courtesy of Bucyrus Erie Co

620
6:324 WORKING ATTACHMENTS

SKIDDERS
Some of the attachments used on a skidder
are: a blade for roughing out skid roads, a
winch, an arch and fairlead, and a grapple
(Figure 6-446 and 6-447). If a skidder has a
grapple the arch is generally hydraulically
raised and lowered to allow the tongs to pick
up the load and lift it for skidding.

(6-446) BLADE
Courtesy 0 International Harvester

(6-446) WINCH
Courtesy of International Harvester

(6-446) GRAPPLE
Courtesy of International Harvester

FAIRLEAD

CB

(6-447) SKIDDER
Courtesy of Intonation! Harvester

621
 WORKING ATTACHMENTS 6:325

GRADERS
A grader blade (Figure 6-448) is longer and
narrower than a dozer blade. The main sec-
tion of the blade is the curved moldboard. Stif-
feners are welded to the back of the mold-
board to give it support. Various mounting
brackets also add support. For protection, a
cutting edge is bolted to the bottom of the
blade and end bits are bolted to the outer
ends.

CIRCLE i
-- 4:-SeA
4x-P-i
MOLDBOARD
TILT CYLINDER

-
SIDE SHIFT CYLINDER
p ,..zu

1, ,;:,,,,,

(6-448) Courtesy of Champion Road Machinery Limited

622
6:326 WORKING ATTACHMENTS

A grader blade has a unique mounting (Figure Two common working attachments found on
6.449). Located between the front and rear graders are rippers and scarifiers. Rippers
wheels under the arch of the main frame. the (Figure 6-450) are mounted at the rear of the
blade is mounted on a mechanism which per- machine. Hydraulic controls raise. lower and
mits the blade to move in the following ways. tilt the rippers. Scarifiers are also
hydraulically operated. Located just ahead of
swing in an arc en a horizontal plane the blade. scarifiers (Figure 6-451) are mount-
from a full left to a full right position. ed to thebolster end of the main frame with a
tilt so that the blade will grade side pivot pin. They have much shorter teeth than a
hills on the left or the right side. ripper and are intended mainly to loosen
extend outward from either side of the material before it reaches the blade. Teeth for
machine. scarifiers and rippers are replaceable.

These blade movements are all hydraulically

operated on modern machine&

(6.449)
Courtesy of Champion Road Machinery Limited

(6-450) RIPPER
Courtesy of Catespillar Tractor Co
(6-451) V-SCARIFIER
Counesy of Wabco Construction and
Mining Equipment

623
 WORKING ATTACHMENTS 6:32T

Special blades are available for graders. For

example, to plow snow a V-plow and a wing
plow can be attached to a grader (Figure 6-
452). The V-piow in front does the initial
clearing, casting !he snow left and right. The
main blade picks up snow behind the V-plow
and sends it to a wing plow which casts the
snow off to the right. The V-plow is
hydraulically operated whereas the wing plow
is usually operated by a combination of cables
and hydraulic cylinders. The wing plow can be
raised for traveling as it is in Figure 6-452.

WING-PLOW

Courtesy of Wabco Construction and

MACHINE BALANCE AND Mining Equipment
COUNTERWEIGHTS
Balance of working attachments and loads is carrying a heavy load. a counterweight can be
an important element in machine design. Take added to the rear of the main frame or ballast
a wheel loader and a crawler loader for exam- can be added to the wheels. Counterweights
ple. The wheel loader has the engine mounted can be actual weights or they can be in the
towards the rear to counterbalance the weight form of attachments such as winches or rip-
of the bucket and load. A crawler loader pers. Figure 6-453 shows a bolt-on coun-
achieves a balance by having the loader terweight for a loader.
frame mounted in the center of the track
frame.
Counterweights are also used for traction. if a
machine under heavy load slips. coun-
In some situations. however, the weight of the terweights can be added to the rear of the
machine cannot adequately counterbalance machine to improve traction. (As discussed in
load weight. I, a wheel or crawler loader ex- the section on tires, ballast added to tires is
pe riences balancing difficulties when also used for this purpose.)

(-453) Courtesy of Caterpillar Tractor Co,

624
6:328 WORKING ATTACHMENTS

Shovels or cranes also use counterweights.

Although these machines have a balance be-
tween the center of the swing axis and the
engine and deck machinery (Figure 6.454).
they still need heavy counterweights at the
rear of the deck. In addition to their balancing
function. counterweights also act as rear
protective bumpers.

CENTERLINE OF SWING AXIS

FRONT END

- ENGINE AND DECK MACHINERY

COUNTERWEIGHT (6-454)
Courtesy of American Hoist and Derrick Co

..?11411

.
*.
Counterweights may be added or removed .
when, for example, a longer or shorter boom E.
is put on the machine or the machine's weight -

is lightened for shipping. Provision is often . It

,
made on machines for using engine power to (6-455)
lift or lower counterweights. One method is an Courtesy of Caterpillar Tracior Ca
over the cab cable pulley setup attached to
the boom, while another is to use hydraulic
cylinders.
Caution: Whenever the front end of a coun-
terweighted machine is removed,
the machine is rear heavy and will
tip °war if not supported.
Crawlers, when equipped with a side boom
(Figure 6-455), will have a counterweight on
the opposite side. Side booms are common on
pipe line work. The counterweight is usually
on a hinged mount so that it can be lifted or
lowered to change the effective leverage of
the weight in proportion to the boom angle
and load. The weight is lifted for traveling to
make the machine narrower.

625
 WORKING ATTACHMENTS 6:329

CANOPIES
Canopies, or ROPS (Roll Over Protection
Structure), are required by law on most heavy
duty machines. A typical ROPS mounting for a
crawler dozer is shown in Figure 6-456.

Sweep Assembly
Lin
1

2 Nuts LIFTING
3 Flat Washers BRACKET
4 Bolts
5 Canopy Assembly
6 Bolts
7 NuIS & Lockwashers

(6-456) ROLLOVER PROTECTIVE STRUCTURE AND MOUNTING HARDWARE

Courtesy of Terex, General Motors Corporation

626
6:330 WORKING ATTACHMENTS

MAINTENANCE AND SERVICE REPAIR 3. Teeth check for worn or missing teeth.
OF WORKING ATTACHMENTS Also check for loose adapters.

DAILY ROUTINE MAINTENANCE 4. Bolt-on cutting edges and wear plates

check for worn edges and loose or
Regular checks of working attachments missing belts.
should be part of preventive maintenance
programs. The checks can be made during 5. Sidecutters check for worn cutters and
the daily walk around inspection. On buckets. for loose or missing bolts. .

dippers. blades. rippers. scarifiers. make the 6. Hydraulic cylinders check for cylinder
relevant checks from Cie list below. Report or hose leaks. Also check that the mounts.
repairs that need attention. pins fittings and hoses are tight.
1. Weld joints check for cracks or wear. Examples of service manual preventive main-
2. Bucket or dipper check for: tenance checks for working implements for a
Caterpillar wheel loader and grader are
(a) corners worn thin shown below.
(b) bent or broken reinforcing gussets.
(c) bending or bell-mouthing of the
bucket.
(d) bottom runners that are worn thin.
(e) worn or cracked mounting brackets
or lugs.

WHEEL LOADER

When Required

Bucket Teeth Inspect condition replace if necessary

Ripper Teeth Inspect condition replace if necessary

GRADER

When Required

Front Mounted Scarifier Tips Change when worn close to shank

Blade Circle Adjust when up and down movement of circle tc

shoes develops

Cutting Edge and End Bits Change when worn close to moldboard.
Ripper Tips Change when worn close to shank.

627
 WORKING ATTACHMENTS 6:331

As mentioned earlier. some companies, especially large ones. have their own P.M. check sheets.
Below are two examples of checks on shovel working attachments taken from company P.M. sheets.

LORNEX MINING CORPORATION

NO. 96 FIELD CREW DAILY CHECK LIST
This Sheet To Be Picked Up In Foreman's Office And Returned At Shift End.

Shovels s s 2 Remark Column

Si gSgg4 cu

I. Adapters. Wedges.
C-C lamps
HHH
?. Teeth
Turned
Replaced or AAA
Note: Longest Teeth to
Operator Side FA
F IF
A ti
IF 1

Wear Caps Side

i RI
5.
Cutters

Trip Cable
I.
UMW
5. Latch Lever Pins and
Locks VOA
5. Latch Bar Dutchman AAA
Shims
Arkr
AFTON MINES
SHIFT PREVENTIVE MAINTENANCE
P & H SHOVEL

DATE: MECH

1900 AL SHOVEL Hr. Reading: 301 302__ 303 301 302 303

1. Dipper Teeth, Caps, Pins

2. Sidecutters. Keepers

3. Adapters, C-Clamps. Wedges

4. Bail Pins. Equalizer Pins. Sheaves, Keepers

5. Stick/Bucket Pins. Pitch Brace Pins and Keepers

6. Trip Cable, Chain Latch Assembly

7. Snubber Brake Assembly

8. General Wear Condition

628
6:332 WORKING ATTACHMENTS

DIPPER DOOR ADJUSTMENTS

Door latches and snubbers on large shovels
need adjusting. Latch bars must be adjusted
to compensate for wear. As the latch bar
length decreases from wear. shims need to be
progressively removed from a shim pack
located beneath the latch lever (Figure 6-457).
Door snubbers. as was mentioned earlier.
prevent dipper doors from slamming. If slam-
ming becomes a problem. the pressure on the
snubber discs has to be increased by
tightening adjusting nuts. When the friction
discs can no longer be tightened. they have to
be replaced. Note that friction discs should
BLOCK BOWL AND APRON BEFORE
never be ...,oricated because they are CHANGING CUTTING EDGE
designed to run dry. OR ROUTING BITS
(6-458)
Counesy of Caterpillar Tractor Co.

BLOCK BLADE BEFORE CHANGING

CUTTING EDGE OR END BITS
(6-458)
Courtesy of Caterpillar Tractor Co.

.41111111111.11Mmar---irm--

(6-457) DIPPER TRIP LATCH BAR (TYPICAL)2246

Counesy of Harnischfeger Corporation P&H

SERVICE REPAIR ON WORKING

ATTACHMENTS
Working attachments are large and heavy and
are therefore potentially dangerous. When in-
specting or working on implements. they
should be lowered to the ground. the engine
should be shut down. and the implement con- BLOCK BUCKET BEFORE
trols put in neutral. In the event that an im- CHANGING BUCKET TEETH OR
plement has to be lifted to inspect its un- SIDECUTTERS
derside or to replace a cutting edge, corner (6.458)
bit. tooth point. adapter. etc.. support the im- Courtesy of Caterpillar Tractor Co.
plement with firm blocking (Figure 6-458).

629
 WORKING ATTACHMENTS 6:333

Points When Removing and Installing Cutting

Edges, Corner Bits, Tooth Points and Adap-
ters (See service manual for specific
procedures).
1. II cutting edge, sidecutter or corner bit
bolts are difficult to remove, and in most
cases they are, remove them with a cut-
ting torch. Note that cutting edges can
sometimes be reversed and reinstalled for
additional service life. Similarly, some cor-
ner bits can be swapped to opposite sides.
Figure 6-459 illustrates removing cutting
edges. sidecutters, and end bits. Figure 6- SCRAPER CUTTING EDGE
460 shows replaceable cutting edges and
(6-459)
corner bits on a dozer blade.
Courtesy of Caterpillar Tractor Co.

GRADER CUTTING EDGE

CLEANING CUTTING EDGE
(6-459) CONTACT SURFACE
Courtesy of Caterpillar Tractor Co.
(6.459)
Courtesy of Caterpillar Tractor Co.

f
C

1. ;71:11SIV f
GRADER END BITS SIDECUTTERS AND MOUNTING BOLTS
(6-459) (6-459)
Courtesy of Caterpillar Tractor Co. Courtesy of Caterpillar Tractor Co.

630
6:334 WORKING ATTACHMENTS

t Cutting Edges
2 R.H. Corner Sit
3 Blade
4 Grease Fitting
5 Bolt & Nut
6 Pin
7 L H. Corner Bit
8 Bolt. Washer & Nut
9 Boll & Nut 10...-1
10 Bolt & Nut
11 Cutting Edge

(6-460) Courtesy 0 Terex. General Motors

2. Clean the areas where new parts are to be
installed and scrape paint from the con-
tact surface of new cutting edges.
sidecutters. and corner bits. Carefully
check the bucket. dipper or blade for
cracks near the bolt -on areas. Use new
bolts to install the parts and torque them
to specification. To ensurs he bolts ...re
seated properly, strike the bolt heads with
a hammer while tightening them. Recheck
bolt torque after one or two shifts.

631
 WORKING ATTACHMENTS 6:335

3. To remove buck^t teeth and ripper

shrouds and tips, a pin must be driven out '4414.44
(Figure 6-461). Some adapters for teeth -"
are also held by pins. Before attempting to .1.

remove a pin, clean around the pin area te."

with a wire brush. When installing new
parts that are held by pins, always use
new pins and new rubber bushings (if
equipped). Note when installing teeth that '.
many of them have a digger side and a
running side, and the desired side has to
be placed face down. Figure 6.461, 6-462,
and 6-463 show the installation and RIPPER
removal of teeth and tips. Courtesy of Caterpillar Tractor Co.

Warning: To avoid eye injuries, wear (6-461) DRIVING OUT PINS

safety glasses when striking
pins. Also. take precautions
that the pin does not fly out
and hit someone nearby.

tY

1-

..

.4k$41,. Aor..
0:4%.":".Nt..
BUCKET
Courtesy of Caterpillar Tractor Co.

SLIDE TIP OVER ADAPTER TO

ALIGN PIN HOLES AND
INSTALL PIN

(6-461) INSTALLING NEW TEETH

Courtesy of Caterpillar Tractor Co

'..z
04
.
(6 -462) EMOVING SCARIFIER TIP
11 I
,

INSTALL NEW TOOTH

OVER WASHER

632 (6-462) INSTALLING SCARIFIER TIP

Courtesy ot Caterpillar Tractor Co.
6:336 WORKING ATTACHMENTS

INSTALL THE TIP AND PIN

INSTALL BUSHING
(6-463) INSTALLING RIPPER TIP AND SHROUD
Courtesy of Esco Corporation
4. welding repairs can be used to repair the INSTALL SHROUD
non-replaceable, or at least the not readily
replaceable. parts of working at-
tachments. The two examples of welding
repairs to a dipper shown in Figures 6-464
and 6-465, would generally be done by a
welding shop.

3.WELD IN NEW PLATE WITH

SIDECUTTER BOLT HOLES

(6-464) REPAIRING DIPPER CORNERS

1. CRACKED OR WORN OUT

AREA NEEDS REPAIR

TEMPLATE FO
SCRIBING
LIP-WING CONTO

2.CUT OUT ENTIRE SECTION BURN BUCKET WALLS

Courtesy of Esco Corporation ALONG THESE LINES
(6-465)CUT OUT WORN LIP WITH
THE AID OF A TEMPLATE,
AND WELD ON A NEW LIP Courtesy of Esco Corporation
san
 WORKING ATTACHMENTS 6:337

QUESTIONS WORKING ATTACHMENTS 14. Give two reasons for adding coun-
terweights to a machine.
1. When selecting a dozer blade, what are
the two main factors to consider? 15. Counterweights can be actual weights or
they can be in the form of
2. True or False? Hardened steel cutting
edges are welded to the bottom edge of 16. What methods do shovels and cranes of-
a dozer blade to extend blade lite. ten have for raising and lowering coun-
terweights?
3. What function does a ripper perform?
17. What safety procedure must be taken if
4. How does a loader bucket mounting dif-
the front end of a counterweighted
fer from a dozer blade mounting? machine is removed?
5. What are the three common types of 18. Part of preventive maintenance programs
protection available for loader buckets? is to make regular checks on working at-
6. What job would a grapple be used for on tachments:
a wheel loader? daily
(a)
7. What is the function of a quick coupling (b) weekly
device for a hydraulic excavator?
(c) monthly
8. The devices used to protect the front cor- (d) twice yearly
ners of an excavator dipper and to aid in
digging are called: 19. Referring to the service mantra: in-
formation given in this section for a
(a) side lips Caterpillar grader, when is it recom-
(b) wear plates mended that scarifier tips be replaced?
(c) tooth points 20. What two maintenance adjustments are
(d) sidecutters required on large shovel dippers?
9. How do shovel dippers differ from ex- (a) dipper door hinge pins and trip lever
cavator dippers? (b) dipper door latch bar and trip lever
10. What device is used to prevent door tc) dipper door latch bar and snubber
slamming on a shovel dipper? (d) dipper door hinge pins and tooth
(a) snuffer points
(b) snubber 21. When working on or inspecting working
door stopper
attachments, what safety precaution
(c)
must be taken?
(d) tension bolt
22. True or False? New parts such as cut-
11. A tooth point used on a shovel dipper is ting edges and corner bits should have
held by a: the paint scraped off their contact sur-
faces to prevent the parts from working
(a) weld loose in service.
(b) bolt
23. Now do you remove bolts on working at-
(c) friction bit tachments that are hard to get oft with a
(d) drift pin wrench?
12. True or False? Adapters for shovel dip- 24. Many bucket teeth are two-sided, having
per teeth are virtually indestructable. a side and a
side.
13. A scarifier on a grader is mounted:
(a) at the rear of the machine
(b) just behind the grader blade
(c) just ahead of the grade blade
(d) ahead of the front wheels

I 634
6:338 WORKING ATTACHMENTS

ANSWERS WORKING ATTACHMENTS 22. True.

1. The size of the dozer's engine. The type 23. Cut them cff with a cutting torch.
of work the dozer will mainly be doing.
24. .... digger running...
2. False. The edges are bolted.
3. A ripper loosens material for easier
dozing.
4. Loader bucket lift arms are attached to a
tower that is part of, or attached to, the
tractor's main frame. A dozer's blade is
attached to trunnions outside the tracks
frames.
5. cutting edges
wear strips
teeth
6. Log loading.
7. For changing working implements
quickly.
8. (d) sidecutters.
9. The shovel dipper has a hinged door at
the bottom for dumping, while excavator
dippers are solid and roll to dump.
10. (b) snubber
11. (d) drift pin
12. False. Running a bucket with an ex-
posed adapter will destroy the adapter.
13. (c) just ahead of the grader blade.
14. counterbalance load weight
improve traction
give rear bumper protection
15. ... attachments.
16. a cable and pully system
hydraulic cylinders
17. Support the rear of the machine.
18. (a) daily.
19. When the tips are worn close to the
shank.
20. (c) dipper door latch bar and snubber.
21. lower all attachments onto good
sound blocking
shut engine down
put controls in neutral

635
 WORKING ATTACHMENTS 6:339

TASKS WORKING ATTACHMENT

ROUTINE MAINTENCE CHECK

1. Inspect the working attachments on one
of the following machines:
Dozer Scraper
Loader Grader
Backhoe Shovel
Excavator
Look for worn or damaged areas. cracks,
welds, bends and twists. Make a service
report and present it to Your supervisor.
The report should include: areas to be
repaired and parts to be replaced such as
bucket teeth (and pins and bushings). rip-
per or scarifier tips. cutting edges. wear
plates, corner or end bits.

SERVICE REPAIR

1. On one of the machines listed above. raise

the working attachment, position blocks.
lower the attachment onto the blocks and
check to see that it is secure. Using the
correct tools and equipment, remove and
install parts ordered in task one. When the
new parts have been installed. raise the
working implement remove the blocks.
and lower the implement to a safe
position.

4
636