2000 - 2001

Industrial
Engine
Systems

Service Manual
3.0 liter
 Contents

CONTENTS

Section 1 ..........................................................................................Technical Data

Section 2 .............................................................................................Maintenance

Section 3 .......................................................................................Troubleshooting

Section 4........................................................................................Starting System

Section 5......................................................................................Charging System

Section 6 ........................................................................................Ignition System

Section 7 ..............................................................................................Fuel System

Section 8 .....................................................................................Governor System

Section 9 ........................................................................................Cooling System

Section 10 .....................................................................3.0L Base Engine Service

No part of this publication may be reproduced, stored in any retrieval system, or transmitted in any form
or by any means, included but not limited to electronic, mechanical, photocopying, recording or otherwise,
without prior written permission of Crusader Engines. This includes all text, illustrations, tables, and
charts.

IES 131 8/99

Contents INDUSTRIAL ENGINE SYSTEMS

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IES 131 8/99

Foreword

FOREWORD
It is important to note that this manual contains • If part replacement is necessary, the replace-
various Warnings, Cautions and Notes that must be ment part must be of the same part number or
carefully observed in order to reduce the risk of an equivalent part. Do not use a replacement
personal injury during service or repair. Improper part of lesser quality. Before using a replace-
service or repair may damage the engine or render ment part, service procedure, or tool which is
it unsafe. It is also important to warn of all not recommended by the engine manufacturer,
hazardous consequences that might result from it must first be determined that neither person-
careless treatment of the engine. Failure to al safety nor the safe operation of the engine
observe these items could influence terms of will be jeopardized by the replacement part,
warranty. service procedure, or tool selected.
• Special service tools shown in this service
manual that have tool product numbers begin-
WARNING ning with “J” or “BT” are available for world-
wide distribution from:
Failure to heed could result in death, injury, or
property damage. Kent-Moore Tools
28635 Mound Road
Warren, Mi. 48092
CAUTION 1-800-345-2233
Mon.-Fri. 8:00 a.m. - 5:00 p.m. EST
Less severe than WARNING, but has the poten- Telex: 244040 KMTR VR
tial to cause injury or damage. Also used to noti- Fax: 1-800-578-7375
fy of situations that could lead to eventual failure,
injury or damage. English and Metric Fasteners

IMPORTANT: Denotes situation which could CAUTION

influence safety of proper performance of the
vehicle or a component. Late model engines use a combination of English
and Metric threaded fasteners. The components
NOTICE: Significant item of information. effected are starter motor, engine mounts, and
“Must Read” Symbols flywheel housing mounting. Verify that the prop-
er fasteners are used whenever removing or
To reduce the chance of personal injury and/or replacing one of these components.
property damage, the following instructions must be
carefully observed.
• Proper service and repair are important to the
safety of the service technician and the safe,
reliable operation of all engines. The service
procedures recommended and described in
this service manual are effective methods of
performing service and repair. Some of these
procedures require the use of tools specially
designed for the purpose.

IES 131 8/99 Foreword-i

 INDUSTRIAL ENGINE SYSTEMS

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Foreword-ii IES 131 8/99

 Section 1
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8/99
31
IES 1

Technical Data
Table of Contents INDUSTRIAL ENGINE SYSTEMS

TABLE OF CONTENTS
3.0L Engine ................................................................................................................................................1-1
General Description .................................................................................................................................1-1
Fuel System .............................................................................................................................................1-2
Air Intake System.....................................................................................................................................1-2
Exhaust System .......................................................................................................................................1-3
Cooling System ........................................................................................................................................1-3
Lubrication System ..................................................................................................................................1-4
Engine Electrical ......................................................................................................................................1-4
Installation Limits .....................................................................................................................................1-4
Technical Data 3.0 Liter Engine

TECHNICAL DATA SHEET

3.0 LITER ENGINE

GENERAL DESCRIPTION

ENGINE TYPE: Inline 4-Cycle L4

COMBUSTION SYSTEM: Naturally Aspirated 1-Venturi Intake Manifold

EXHAUST SYSTEM: Cast Iron, Dry or Water Jacketed

VALVE CONFIGURATION: Pushrod Actuated Overhead Valves - 2 Per Cylinder

DISPLACEMENT: 3.0 L (181 CID)

BORE: 101.60 mm (4.00 in.)

STROKE: 91.44 mm (3.60 in.)

COMPRESSION RATIO: 8.2:1 (RN, RS, RA) or 9.25:1 (RM, RF)

FIRING ORDER: 1-3-4-2

SPARK PLUGS: LPG: AC R46TS (0.045 in.)

Natural Gas: AC R46TS (0.045 in.)

WEIGHT: 165 Kg (363 lbs.) Dry (Base Engine)

ROTATION: Counter-Clockwise (CCW) When Viewed From Flywheel End

FUEL TYPE: LPG or Natural Gas

MAXIMUM RPM @ FULL LOAD: 3600 RPM Intermittent Operation

2600 RPM Continuous Operation

IDLE RPM: 700 RPM

TIMING: LPG: 12° BTDC(1)

Natural Gas: 16° BTDC(1)

MOMENT OF INERTIA: 0.3091 Kg M2 (2.735 in. - LBF-S2) w/ Manual Flywheel

NOTE (1): Base timing should be set with advance electronically locked out. Refer to timing procedures.

IES 131 8/99 1-1

3.0 Liter Engine INDUSTRIAL ENGINE SYSTEMS
FUEL SYSTEM
NATURAL GAS FUEL:
FUEL MIXER INLET PRESSURE: +140 mm Wg ± 12.7 mm Wg (+5.5 in. WC ± 0.5 in. WC) @ Idle
GAS PRESSURE @ LPR INLET: 177 - 356 mm Wg (7 - 14 in. WC)

Mixer: IMPCO FB125M

Recommended Regulator(2): IMPCO IMP-53
Regulator Fuel Inlet Sizes: 1" NPT inlet & outlet ports
Air/Fuel Mixture: 2% Oxygen @ Rated Power and Speed

PROPANE (LPG) Liquid:

FUEL MIXER INLET PRESSURE: -51 mm Wg ± 12.7 mm Wg (-2.0 in. WC ± 0.5 in. WC) @ Idle
GAS PRESSURE @ LPR INLET: Full Tank Pressure

Mixer: IMPCO CA100M (air valve CV1-16-2)

Recommended Regulator(2): IMPCO Model EB w/VFF30 Vacuum Fuelock Filter (3)
Fuel Inlet Sizes: VFF30 - 1/4" NPT liquid fuel inlet & outlet ports
EB Regulator - 1/4" NPT liquid fuel inlet - 1" NPT fuel outlet
Air/Fuel Mixture: 0.5 to 1.5% CO @ Rated Power and Speed

PROPANE (LPG) Vapor:

FUEL MIXER INLET PRESSURE: -51 mm Wg ± 12.7 mm Wg (- 2.0 in. WC ± 0.5 in. WC) @ Idle
GAS PRESSURE @ LPR INLET: 177 - 356 mm Wg (7 - 14 in. WC)

Mixer: IMPCO CA100M (air valve CV1-16-2)

Recommended Regulator(2): IMPCO IMP-53 mounted upside-down w/spring removed (2)

Regulator Fuel Inlet Sizes: 1" NPT inlet & outlet ports
Air/Fuel Mixture: 0.5 to 1.5% CO @ Rated Power and Speed

AIR INTAKE SYSTEM

MINIMUM INTAKE
AIR FLOW RATE: 4.11 m3/min. (145 CFM)

MAXIMUM ALLOWABLE w/Clean Element : 254 mm Wg (10 in. WC)

INTAKE RESTRICTION: w/Dirty Element: 508 mm Wg (20 in. WC)

MAXIMUM ALLOWABLE Maximum Allowable Temperature Rise between Ambient and

TEMPERATURE: Engine Air Inlet is 16.7°C (30°F).

NOTE (2): All regulators should be mounted within 457.2 mm (18 in.) of the mixer for best operation.
NOTE (3): A balance line should be installed between the regulator and mixer if engine is to be operated in
dirty or dusty environment. (Balance line fittings are 1/8" NPT)

1-2 IES 131 8/99

Technical Data 3.0 Liter Engine

EXHAUST SYSTEM
EXHAUST GAS FLOW RATE 272 CFM @ 2600 RPM
AT MAXIMUM POWER: 447 CFM @ 3600 RPM

MAXIMUM EXHAUST GAS 527°C (980°F) @ 2600 RPM

TEMPERATURE @ FULL LOAD: 677°C (1250°F) @ 3600 RPM

MAXIMUM ALLOWABLE
BACK PRESSURE: 18.7 kPa (2.5 PSI)

MINIMUM ALLOWABLE
EXHAUST PIPE SIZE: 38 mm (1-1/2 in.)

COOLING SYSTEM
MAX COOLANT TEMPERATURE
@ TOP TANK OF RADIATOR: 98°C (210°F) @ 2600 RPM

WATER PUMP ROTATION: (viewed from front) w/V-Belt Drive - Clockwise (CW)

MAXIMUM RESTRICTION
AT PUMP INLET: 10 kPa (1.5 PSI)

THERMOSTAT: LPG: Opening Temperature: 82°C (180°F)

Fully Open Temperature: 96°C (205°F)
NG: Opening Temperature: 71°C (160°F)
Fully Open Temperature: 85°C (185°F)

COOLING WATER CAPACITY

(block only): 3.8 L (4.0 qts.)

IES 131 8/99 1-3

3.0 Liter Engine INDUSTRIAL ENGINE SYSTEMS
LUBRICATION SYSTEM
OIL PRESSURE (MIN. HOT): 28 kPa (4 psi) @ 700 RPM
207 - 414 kPa (30 - 60 psi) @ 2000 RPM

OIL TEMPERATURE: Upper Limit: 130°C (266°F)

Recommended: 99 - 110°C (210 - 230°F)
Lower Limit: 80°C (176°F)

NOTE: Oil Cooler Required w/Standard Oil Pan (Stationary Applications Only)

CRANKCASE CAPACITY: Standard Pan: 4.7 L (5.0 qts.)

Optional Pan: 26.5 L (28 qts.)
Oil Filter: 0.9464 L (1 qt.)

ENGINE OIL SPECIFICATION: API - SG/SH, SAE 10W30 - All Temperatures

SAE 15W40 - Above -18°C (0°F)
SAE 30W - Between 5° and 27°C (40° and 80°F)
SAE 40W - Above 27°C (80°F)

ENGINE ELECTRICAL
IGNITION TYPE: Delco EST w/Electronic Advance

STARTER MOTOR: Delco SD300 / 12 volt Negative Ground (-) (12.75” Flywheel)
Delco PG260 / 12 volt Negative Ground (-) (14.00” Flywheel)

FLYWHEEL TEETH: 12.75 in. Flywheel 153

14.00 in. Flywheel 168

BATTERY REQUIREMENT: 12 volt - 485 CCA (90 AH)

ALTERNATOR: 12 volt - Mando 51 Amp

INSTALLATION LIMITS
MAXIMUM ANGULARITY
LIMITS ON ENGINE: Front of engine down: 8.5°
Rear of engine down: 18°
Side to side: 20°

1-4 IES 131 8/99

Table of Contents INDUSTRIAL ENGINE SYSTEMS

TABLE OF CONTENTS
Maintenance ..............................................................................................................................................2-1
Accessory Drive Belts ..............................................................................................................................2-1
Engine Crankcase Oil ..............................................................................................................................2-1
Changing Engine Oil and Filter................................................................................................................2-2
Cooling System ........................................................................................................................................2-2
Engine Compression Check ....................................................................................................................2-3
Scheduled Maintenance Chart.................................................................................................................2-4

2-i CENG 131 8/98

Maintenance General Information

MAINTENANCE
All Crusader Industrial Power Products require a
certain amount of maintenance. Suggested main-
tenance requirements are contained in this section.
The owner should, however, develop his own main-
tenance schedule using the requirements listed in
this Section and any other necessary requirements
resulting from optional additions to the engine
system.

ACCESSORY DRIVE BELTS

WARNING
Engine must be shut off and the ignition key
removed before inspecting drive belts.

V-Belt Systems
150-141
Check belt tension by pressing down on the
Figure 2-1 Engine Oil Viscosity
midway point of the longest stretch between two
Recommendation
pulleys. The belt should depress 1/2 in. (13 mm). If
depression is more than allowable, adjust tension.
Use of Supplemental Additives
Serpentine Belt Systems Engine oils meeting Crusader Industrial Power
Products’ recommendations already contain a
Serpentine belt systems use a spring-loaded balanced additive treatment. The use of supple-
tensioner which keeps the belt properly adjusted mental additives which are added to the engine oil
automatically. by the customer are unnecessary and may be
harmful. Cruasder does not review, approve, or
ENGINE CRANKCASE OIL recommend such products.
Figures 2-1 and 2-2
Synthetic Oils
Oil Recommendations
Synthetic engine oils are not recommended for
Prior to changing oil, select an oil based on the use in Crusader Industrial Power Products.
prevailing daytime temperature in the area in which Synthetics may offer advantages in cold-tempera-
the engine is operated. The chart in figure 2-1 is a ture pumpability and high-temperature oxidation
guide to selecting the proper crankcase oil. Refer resistance. However, synthetic oils have not proven
also to Section 1 for additional information. to provide operational or economic benefits over
conventional petroleum-based oils in Crusader
IMPORTANT: Oils containing “solid” additives,
Industrial Power Products. Their use does not
non-detergent oils, or low-quality oils are not
permit the extension of oil change intervals.
recommended for use in Crusader Industrial
Power Products.

IES 131 8/98 2-1

General Information INDUSTRIAL ENGINE SYSTEMS
Checking/Filling Engine Oil Level CHANGING ENGINE OIL AND FILTER
IMPORTANT: Care must be taken when check- IMPORTANT: When changing the oil, always
ing engine oil level. Oil level must be main- change the oil filter.
tained between the “ADD” mark and the “FULL”
mark on the dipstick. To ensure that you are not 1. Start engine and run until it reaches normal
getting a false reading, make sure the following operating temperatures.
steps are taken before checking the oil level. IMPORTANT: Change oil when engine is warm
1. Stop engine if in use. from operation as It flows more freely, carrying
2. Allow sufficient time (approximately 5 minutes) away more impurities.
for the oil to drain back into the oil pan. 2. Stop engine.
3. Remove dipstick. Wipe clean and reinstall. 3. Remove drain plug and allow all the oil to
Push dipstick all the way into the dipstick tube. drain.
4. Remove dipstick and note the oil level. 4. Remove and discard oil filter and its sealing
5. Oil level must be between the “FULL” and ring.
“ADD” marks (figure 2-2). 5. Coat sealing ring on new filter with clean
engine oil, and install new filter. Tighten filter
securely (following filter manufacturer’s
instructions). Do not overtighten.
6. Fill crankcase with oil.
7. Start engine and check for oil leaks.

COOLING SYSTEM

131-160 CAUTION
Figure 2-2 Engine Oil Dipstick (Typical)
Alcohol- or methanol-based antifreeze or plain
water are not recommended for use in the cool-
6. If the oil level is below the “ADD” mark,
ing system at anytime.
proceed to Steps 7 and 8, and reinstall dipstick
into the dipstick tube.
Crusader Industrial Power Products recommends
7. Remove oil filler cap from the valve rocker arm that the cooling system be filled with a 50/50
cover. mixture of ethylene glycol antifreeze and water.
8. Add required amount of oil to bring level up to, Crusader Industrial Power Products can use any
but not over, the “FULL” mark on dipstick. type of permanent antifreeze or any brand
antifreeze solution that meets GM Specification
CAUTION 1825M or 1899M which will not damage aluminum
parts.
Overfilled crankcases (oil level being too high)
can cause a fluctuation or drop in oil pressure
and rocker arm “clatter” on engines. The overfill
condition results in the engine crankshaft splash-
ing and agitating the oil, causing it to foam
(become aerated). The aerated oil causes the
hydraulic valve lifters to “bleed down.” This, in
turn, results in rocker arm “clatter”and loss of
engine performance due to the valves not open-
ing properly.

2-2 IES 131 8/98

Maintenance General Information

Checking Coolant Level 7. If some cylinders have low compression, inject

about one tablespoon (15 ml or about three
Do not remove cooling system pressure cap when
squirts from a pump-type oil can) of engine oil
engine is hot. Allow engine to cool and then
into the combustion chamber through the
remove cap slowly allowing pressure to vent. Hot
spark-plug hole. Recheck compression.
coolant under pressure may discharge violently.
8. Minimum compression recorded in any one
1. Check coolant level in coolant recovery tank. cylinder should not be less than 70% of the
Add specified coolant as required. highest cylinder, and no cylinder should read
2. Periodically remove the pressure cap from the less than 100 psi (690 kPa). For example, if
filler neck to ensure the coolant recovery the highest pressure in any one cylinder is 150
system is functioning properly. Coolant must psi (1035 kPa), the lowest allowable pressure
be at the top of the filler neck. If coolant is low, for any other cylinder would be 105 psi (725
check gasket in cap for damage. Replace if kPa), since 150 x 70% = 105 (1035 x 70% =
necessary. Inspect coolant recovery system 725).
for leaks. • Normal condition - compression builds up
quickly and evenly to the compression spec-
ENGINE COMPRESSION CHECK ified on each cylinder.
1. Disconnect the primary lead from the distribu- • Piston rings leaking - low compression on
tor. first stroke tends to build up on following
2. Remove all spark plugs. strokes but does not reach normal.
Improves considerably with addition of oil.
3. Block the throttle plate and choke plate (if
equipped) into the wide-open position. • Valves leaking - low compression on first
stroke. Does not tend to build up on follow-
4. Make sure the battery is fully charged.
ing strokes. Does not improve much with
5. Starting with the compression gauge at zero, addition of oil.
crank the engine through four compression
• If two adjacent cylinders have lower than
strokes.
normal compression, and injecting oil into
6. Make the compression check at each cylinder cylinders does not increase the compres-
and record each reading. sion, the cause may be a head gasket leak
between the cylinders.

IES 131 8/98 2-3

General Information INDUSTRIAL ENGINE SYSTEMS

SCHEDULED MAINTENANCE CHART

131-168

Figure 2-3 Maintenance Intervals

2-4 IES 131 8/98

Table of Contents INDUSTRIAL ENGINE SYSTEMS

TABLE OF CONTENTS
Engine Performance ...............................................................................................................................3-1

Engine Starting Problems ......................................................................................................................3-1

Charging System Problems ...................................................................................................................3-2

Instrument Problems ..............................................................................................................................3-2

Engine Noise ...........................................................................................................................................3-3

Oil Pressure Diagnostics .......................................................................................................................3-5

Oil Pressure Problems ...........................................................................................................................3-6

Water In Engine .......................................................................................................................................3-7

Engine Overheating ................................................................................................................................3-8

Vacuum Gauge Diagnostics...................................................................................................................3-9

3-i IES 131 8/99

Troubleshooting

TROUBLESHOOTING

ENGINE PERFORMANCE
Symptom Cause
1. Poor engine idle. A. Clogged air breather.
B. Improper idle-fuel mixture adjustment.
C. Cap or spark-plug wires arcing.
D. Low grade fuel.
E. Incorrect ignition timing.
F. Spark plugs (fouled, burned, cracked porcelain).
G. Spark plug wires broken or faulty insulation.
H. Defective coil.
I. Cracked or dirty distributor cap.
J. Dirty carburetor.
K. Leak at intake manifold or carburetor base.
L. Low compression. (Check for blown head gasket).
M. Loose or worn distributor.
N. Head gasket, exhaust manifold, cracked head or valve seat.

2. Poor engine acceleration. A. Idle mixture screw.

B. Incorrect ignition timing.
C. Incorrect distributor advance curve.
D. Cracked or dirty distributor cap or rotor.
E. Vacuum leak on the intake manifold or carburetor base.
F. Spark plugs (fouled, burned, wrong heat range, cracked
porcelain).
G. Dirty carburetor.
H. Low compression.

ENGINE STARTING PROBLEMS

The following information will help to locate the starting problem:
1. Determine which engine system is causing the problem. To make an engine run, basic compo-
nents - fuel, spark (ignition) and compression - are required. If all three components are
present, the engine should run. If any one of the three is missing, weak or arriving at the wrong
time, the engine will not run.

2. Determine if there is fuel present.

3. Check ignition system operation. Using appropriate spark tester, check for spark at coil and at
each spark plug. If there is a spark at the spark plug wires, remove the spark plugs and make
sure they are the correct type and heat range, and not fouled or burned.

4. Run a compression check on the engine to make sure it is mechanically sound.

IES 131 8/98 3-1

 INDUSTRIAL ENGINE SYSTEMS

ENGINE STARTING PROBLEMS (CONTINUED)

Symptom Cause
1. No spark. A. Distributor cap or spark plug leads arcing.
B. Spark plugs fouled, burned or cracked porcelain.
C. Spark plug wires are broken or have faulty insulation.
D. Battery, electrical connections, damaged wiring.
E. Ignition switch.
F. Faulty ignition components.
G. Cracked or dirty distributor cap.
H. Shorted tachometer. (Disconnect tachometer and try again).
2. Engine will not crank over. A. Battery charge low, damaged wiring or loose electrical
connections.
B. Circuit breaker tripped (if equipped).
C. Bad ignition switch.
D. Bad starter solenoid.
E. Defective starter motor.

CHARGING SYSTEM PROBLEMS

Symptom Cause
1. Gauges indicate no A. Loose or broken drive belt.
battery charge. B. Loose or corroded electrical connections.
C. Faulty ammeter or voltmeter.
D. Battery will not accept charge.
E. Faulty alternator or regulator.
2. Noisy alternator. A. Loose mounting bolts.
B. Worn, frayed or loose drive belt.
C. Loose drive pulley.
D. Worn or dirty bearings.
E. Faulty diode trio or stator.

INSTRUMENT PROBLEMS
Symptom Cause
1. Malfunctioning A. Faulty wiring, loose or corroded terminals.
instruments or gauges. B. Bad key switch.
C. Faulty gauge.
D. Faulty sender.

3-2 IES 131 8/98

Troubleshooting

ENGINE NOISE
No definite rule or test will positively determine the source of engine noise. Therefore, use the follow-
ing information only as a general guide to engine noise diagnosis.
1. Use a timing light to determine if noise is timed with engine rpm or one-half engine rpm. Noises
timed with engine rpm are related to crankshaft, rods, pistons, piston pins or flywheel. Noises
timed to one-half engine rpm are valve-train related.

2. The use of a stethoscope can aid in locating a noise source. However, because noise will travel
to other metal parts not involved in the problem, caution must be exercised.

3. If noise is believed to be confined to one particular cylinder, ground the spark plug leads one at
a time. If noise lessens noticeably or disappears, it is isolated to that particular cylinder.

4. Try to isolate the noise to location in engine, front to back, top to bottom. This can help
determine which components are at fault.

5. Sometimes noises can be caused by moving parts coming in contact with other components.
Examples are: flywheel, crankshaft striking (pan and pan baffle), rocker arm striking valve cover
or loose flywheel cover. In many cases, if this is found to be the problem, a complete engine
teardown is not necessary.

6. When noise is isolated to a certain area and component, removal and inspection will be
required. Refer to proper sections of service manual for pertinent information.
Symptom Cause
1. Noise around the A. Rocker arm striking valve cover.
valve cover area. B. Rocker arm out of adjustment.
C. Worn rocker arm.
D. Bent push rod.
E. Collapsed lifter.
2. Noise around the A. Sticking valve.
cylinder area. B. Carbon build-up.
C. Connecting rod installed wrong.
D. Bent connecting rod.
E. Piston.
F. Piston rings.
G. Piston pin.
H. Cylinder worn.
3. Noise around camshaft A. Loss of oil pressure.
area (throughout engine). B. Valve lifters.
C. Cam bearings.
4. Noise in camshaft area A. Camshaft timing gear.
area (front of engine). B. Timing chain.
C. Fuel pump.
D. Valve lifter.
E. Cam bearings.

IES 131 8/98 3-3

 INDUSTRIAL ENGINE SYSTEMS

ENGINE NOISE (CONTINUED)

Symptom Cause
5. Noise in camshaft area A. Valve lifter.
(center of engine). B. Cam bearings.
6. Noise in camshaft area A. Distributor gear.
(rear of engine). B. Valve lifter.
C. Cam bearings.
7. Noise in crankshaft area A. Loss of oil pressure.
(throughout engine). B. Main bearings.
C. Rod bearings.
8. Noise in crankshaft area A. Crankshaft timing gear.
(front of engine). B. Timing chain.
C. Main bearing.
D. Rod bearing.
9. Noise in crankshaft area A. Crankshaft striking pan or pan baffle.
(center of engine). B. Main bearing.
C. Rod bearing.
10. Noise in crankshaft area A. Loose flywheel cover.
(rear of engine). B. Loose flywheel.
C. Drive plate.
D. Main bearing.
E. Rod bearing.
11. Engine spark knock. A. Advanced timing.
B. Low quality fuel.
C. Engine running hot.
D. Carbon deposits in engine.
12. Popping through A. Wrong ignition timing.
carburetor. B. Carburetor set too lean.
C. Faulty accelerator pump (gasoline).
D. Vacuum leak.
E. Valve adjustment.
F. Valve timing.
G. Burned or stuck valve.
13. Hissing. A. Vacuum leak.
B. Leaking exhaust (manifolds or pipes).
C. Loose cylinder heads.
D. Blown head gasket.
14. Whistle. A. Vacuum leak.
B. Dry or tight bearing in an accessory.

3-4 IES 131 8/98

Troubleshooting

ENGINE NOISE (CONTINUED)

Symptom Cause
15. Sparks jumping. A. Defective high-tension cables.
B. Cracked coil tower.
C. Cracked distributor cap.
16. Squeaks or squeals. A. Drive belt slipping.
B. Dry or tight bearing in an accessory.
C. Parts rubbing together.

OIL PRESSURE DIAGNOSTICS

The following table contains important information for the checking of oil pressure.
Condition Information
1. Measuring oil pressure. Use a good automotive oil pressure test gauge. Do not rely on
the oil pressure gauge in the instrument panel.

2. Check engine oil level. Oil level should be between the "ADD" and "FULL" marks.

3. Oil level in crankcase May cause loss of engine speed, oil pressure gauge
above "FULL" mark. fluctuation, drop in oil pressure and hydraulic valve lifter noise
at high RPM.

4. Oil level in crankcase Low oil pressure, oil pressure gauge fluctuation, internal below
at or below “ADD” mark. engine noise and/or damage.

5. Change in oil pressure. This may be a normal condition. Oil pressure may read high in
the cooler times of the day and when engine is not up to
operating temperature. As the air temperature warms up and
the engine is running at normal operating temperature, it is
normal for oil pressure to drop off slightly.

6. Low engine oil pressure With modern engines and engine oils, low oil pressure readings
at idle or high rpm. at idle or high rpm do not necessarily mean there is a problem. If
valve lifters do not "clatter" (at idle), there is a sufficient volume of
oil to lubricate all internal moving parts properly. The reason for
the drop in oil pressure is that engine heat causes an expansion
of the internal tolerances in the engine and, the oil will thin out
somewhat from heat.

7. Engine-to-engine variance. It is not uncommon to see different oil pressure readings between
like engines, as long as they fall within specifications. Differences
in oil pressure can be attributed to differences in engine
tolerances, gauges, wiring, senders, etc.

IES 131 8/98 3-5

 INDUSTRIAL ENGINE SYSTEMS

OIL PRESSURE PROBLEMS

Symptom Cause
1. Low oil pressure. A. Low oil level in crankcase.
B. Defective oil-pressure gauge and/or sender.
C. Oil broken down, contains water, wrong viscosity, engine
running too hot or too cold, excessive idling with cold water
(condensation).
D. Relief valve stuck open, pickup tube restricted, worn parts in
oil pump, air leak on suction side of oil pump or pickup tube.
E. Oil passage plugs leaking, cracked or porous cylinder block.
F. Excessive bearing clearance.
2. High oil pressure. A. Wrong viscosity, oil full of sludge or tar.
B. Defective oil pressure gauge and/or sender.
C. Clogged or restricted oil passage.
D. Oil pump relief valve stuck closed.

IMPORTANT: Oil pressure slightly higher than normal does not always indicate a problem.
Tolerance stack-up In the engine, oil viscosity or weather conditions could cause high oil pres-
sure.

3. Excessive oil consumption. A. Oil leaks.

B. Oil diluted or of the wrong viscosity.
C. Oil level too high.
D. Drain holes in cylinder head plugged causing flooding of valve
guides.
E. Defective valve seals.
F. Intake manifold gasket leaking, worn valve stem or valve
guides.
G. Defective oil cooler (if so equipped).
H. Glazed, scuffed, worn, stuck, improperly installed; ring
grooves worn; improper break-in; wrong end gap.
I. Piston out-of-round, scored, tapered, glazed; excessive
piston-to-cylinder clearance; cracked piston.

NOTE: Normal consumption is approximately one quart of oil in 3-10 hours of operation at W.O.T.

3-6 IES 131 8/98

Troubleshooting

WATER IN ENGINE
Determine location of water in engine. This information is necessary to determine where the water
came from and how it got into the engine. The most common problems are water on top of pistons
and/or water in crankcase oil.
1. After locating the water, remove all the water from the engine by removing all spark plugs and
pump cylinders by cranking engine over. Next change oil and filter. Start engine and see if
problem can be duplicated. If so, there is more than likely a mechanical problem. If problem
cannot be duplicated, it is either an operator error or a problem that exists only under certain
environmental conditions.
2. If water is confined to cylinders, it is usually entering through the intake system, exhaust system
or head gasket.
3. If the water is confined to crankcase, it is usually caused by a cracked or porous block or
condensation.
4. If the water is located in both the cylinders and the crankcase, it is usually caused by water in
the cylinders getting past the rings and valves.
5. Checking for rust in the intake manifold or exhaust manifolds is a good idea. Rust in these
areas will give clues if the water entered through these areas.

Symptom Cause
1. Water found on top of A. Cracked exhaust manifold (water cooled).
the pistons. B. Improper manifold-to-elbow gasket installation (water cooled).
C. Loose cylinder head bolts.
D. Blown cylinder head gasket. (Check for warped cylinder head
or cylinder block).
E. Cracked valve seat.
F. Porous or cracked casting (check engine).
2. Water found in the A. Water seeping past piston rings or valves.
crankcase oil. B. Engine running cold (defective thermostat) causing
condensation.
C. Intake manifold leaking near a water passage.
D. Cracked or porous casting.

IES 131 8/98 3-7

 INDUSTRIAL ENGINE SYSTEMS

ENGINE OVERHEATING
Symptom Cause
1. Mechanically related. A. Engine rpm below specification for W.O.T. (engine laboring).
B. Wrong ignition timing.
C. Spark plug wires crossed (wrong firing order).
D. Lean fuel mixture.
E. Wrong heat range spark plugs.
F Exhaust restriction.
G. Valve timing off caused by a jumped or improperly installed
timing chain and/or gears.
H. Blown head gasket(s).
I. Insufficient lubrication to moving parts of engine.
2. Cooling system related. A. Loose or broken drive belt.
B. Water shut-off valve partially or fully closed (if equipped).
C. Clogged or improperly installed water strainer (if equipped).
D. Water inlet hose kinked or collapsed.
E. Water pickup clogged.
F. Defective thermostat.
G. Obstruction in cooling system such as casting flash, sand, or
rust.
H. Engine circulating pump defective.
I. Low coolant level.
J. Antifreeze not mixed properly.
K. Heat exchanger cores plugged.

3-8 IES 131 8/98

Troubleshooting

VACUUM GAUGE DIAGNOSTICS

Gauge Reading Probable Cause
1. Steady reading ranging A. Normal.
between 15 to 21 in. at
idle rpm.
2. Extremely low reading A. Vacuum leak.
but steady at idle rpm. B. Incorrect timing.
3. Fluctuates between high A. Blown head gasket between two adjacent cylinders.
and low at idle rpm.
4. Fluctuates 4 or 5 in. very A. Carburetor needs adjustment.
slowly at idle rpm. B. Spark plug gap too narrow.
C. Valves are sticking.
5. Fluctuates rapidly at A. Valve guides are worn.
idle rpm and steadies as
the rpm is increased.
6. Continuously fluctuates A. Burned or leaking valve.
between low and normal
reading at regular
intervals at idle rpm.

IES 131 8/98 3-9

 INDUSTRIAL ENGINE SYSTEMS

THIS PAGE WAS INTENTIONALLY LEFT BLANK

3-10 IES 131 8/98

Table of Contents INDUSTRIAL ENGINE SYSTEMS

TABLE OF CONTENTS
General Information..................................................................................................................................4-1
Cranking Circuit .......................................................................................................................................4-1
Starter Motor ............................................................................................................................................4-1
Diagnosis .................................................................................................................................................4-1
Starter Motor Noise Diagnosis Chart .......................................................................................................4-2

SD300 Starter Motor .................................................................................................................................4-3

Identification .............................................................................................................................................4-3
Starter Motor Maintenance ......................................................................................................................4-3
Starter Motor Removal.............................................................................................................................4-3
Starter Motor Disassembly.......................................................................................................................4-3
Cleaning and Inspection ..........................................................................................................................4-4
Armature Tests .........................................................................................................................................4-4
Field Coil Tests.........................................................................................................................................4-4
Loose Electrical Connections...................................................................................................................4-5
Starter Motor Assembly ...........................................................................................................................4-6
Starter Motor Adjustments .......................................................................................................................4-6
Starter Motor Installation..........................................................................................................................4-8
Solenoid Removal ....................................................................................................................................4-8
Solenoid Switch Installation .....................................................................................................................4-8
Solenoid Switch Testing ...........................................................................................................................4-8

PG260 Starter Motor .................................................................................................................................4-9

Identification .............................................................................................................................................4-9
Lubrication................................................................................................................................................4-9
Solenoid Replacement .............................................................................................................................4-9
Starter Replacement ..............................................................................................................................4-10
No Load Test..........................................................................................................................................4-10
Starter Motor Disassembly.....................................................................................................................4-11
Cleaning, Inspection, and Testing ..........................................................................................................4-11
Starter Motor Assembly .........................................................................................................................4-13
Checking Pinion Clearance....................................................................................................................4-15
Torque Specifications .............................................................................................................................4-16
General Specifications ...........................................................................................................................4-16

4-i IES 131 8/99

Starting System General Information

GENERAL INFORMATION
English and Metric Fasteners DIAGNOSIS
Before removing any unit in a cranking circuit for
CAUTION repair, the following checks should be made:
Battery - Refer to the appropriate service manual
Late model engines use a combination of English
to determine battery condition.
and Metric threaded fasteners. The components
effected are starter motor, engine mounts, and Wiring - Inspect wiring for damage. Inspect all
flywheel housing mounting. Verify that the prop- connections to the starter motor, solenoid, ignition
er fasteners are used whenever removing or switch, battery and all ground connections. Clean
replacing one of these components. and tighten all connections as required.
Starter Solenoid and Ignition Switch - Inspect
CRANKING CIRCUIT to determine their condition.
The cranking circuit consists of the battery, starter Starter Motor Noise - To correct starter motor
motor, and ignition switch. noise during starting, use the following procedure:
1. Refer to Starter Motor Noise Diagnosis Chart
STARTER MOTOR in this Section to determine the problem.
Two different starter motors are used on GM 2. When starter motor noise diagnosis indicates
engines. The SD300 is a straight drive starter with that the pinion should be closer to the flywheel,
the pinion driven directly by the armature shaft. check to make sure the proper starter motor
Each starter has pole pieces arranged around the was installed. When initial starter motor instal-
armature that are energized by wound field coils. lation is performed, shim(s) are not used.
The PG260 achieves gear reduction at a ratio of 3. When starter motor noise diagnosis indicates
5:1 through planetary gears. It’s relatively small that the pinion should be moved away from the
size and light weight offers improved cranking flywheel, add 0.015 inch double shims until
performance and reduced current requirements. noise disappears (do not exceed 0.045 inch-
es).
Solenoid windings are energized when the igni-
tion switch is in the start position. The resulting Starter Motor - If the battery, wiring and switches
plunger and shift lever movement causes the pinion are in satisfactory condition, and the engine is
to engage the engine flywheel ring gear, the sole- known to be functioning properly, remove the motor
noid main contacts to close, and cranking takes and refer to Starter Motor Disassembly, Test and
place. When the engine starts, the pinion over- Assembly procedures in the appropriate Section.
running clutch protects the armature from excessive Never operate the starter motor more than 30
speed until the ignition switch or engine control seconds at a time without pausing to allow it to cool
switch is released, at the time the plunger return for at least 2 minutes. Overheating, caused by
spring causes the pinion to disengage. To prevent excessive cranking, seriously damages the starer
excessive overrunning, release the ignition switch motor.
or engine control switch from the crank position as
soon as the engine starts.

IES 131 8/98 4-1

General Information INDUSTRIAL ENGINE SYSTEMS

STARTER MOTOR NOISE DIAGNOSIS CHART

131-075

4-2 IES 131 8/98

Starting System SD300 Starter

SD300 STARTER MOTOR

IDENTIFICATION STARTER MOTOR DISASSEMBLY
Figure 4-1 Figure 4-2 through 4-4
The starter identification number is stamped into 1. Remove solenoid switch and mounting screws
the starter-motor end cap (figure 4-1). Always refer (figure 4-2).
to this number when servicing or ordering parts.

22664-008

22664-007
Figure 4-2 Solenoid Screw Removed
Figure 4-1 Starter Motor I.D. Number 2. Remove screw from solenoid connector.
3. Rotate solenoid housing and remove solenoid
STARTER MOTOR MAINTENANCE and plunger spring.
The starter motor and solenoid are completely 4. Remove end cap through-bolts, end cap,
enclosed in the drive housing to prevent entrance of washer and field frame (figure 4-3).
moisture and dirt. Periodic inspection, however, is 5. Remove center bearing-plate screws and
required as follows: remove armature from housing (figure 4-4).
1. Inspect terminals for corrosion and loose 6. Slide thrust collar off armature shaft.
connections. 7. Drive retainer ring collar toward armature.
2. Inspect wiring for frayed and worn insulation. 8. Remove snap ring, retaining collar, clutch
3. Check the mounting bolts for tightness. assembly and bearing plate.

STARTER MOTOR REMOVAL

WARNING
Disconnect battery cables at battery before
removing starter.

1. Disconnect battery cables from battery.

2. Disconnect wires from starter solenoid termi-
nals.
3. Remove starter mounting nuts.
4. Pull starter assembly away from flywheel and 22664-009

remove it from engine. Figure 4-3 End Frame Removal

IES 131 8/98 4-3

SD300 Starter INDUSTRIAL ENGINE SYSTEMS
6. Check fit of bushing in commutator end cap. If
bushing is damaged or worn excessively,
replace end cap assembly. Apply SAE 20 oil
to bushing before reassembly. Avoid exces-
sive lubrication.
7. Inspect armature commutator. If rough or out-
of-round, turn down and undercut. Inspect
points where armature conductors join
commutator bars for good, firm connection.
Burned commutator bar usually is evidence of
poor connection.

ARMATURE TESTS
22664-010
Figure 4-5
Figure 4-4 Bearing Plate and Armature
Test For Short Circuits
CLEANING AND INSPECTION Check armature for short circuits by placing on
growler and holding hacksaw blade over armature
With the starter motor completely disassembled, core while rotating armature (figure 4-5). If saw
except for removal of field coils, component parts blade vibrates, armature is shorted. After cleaning
should be cleaned and inspected. Field coils between commutator bars, recheck. If saw blade
should be removed only when defects are indicated still vibrates, replace armature.
by tests. Defective parts should be replaced or
repaired. Test For Grounded Circuit
1. With continuity meter, place one lead on arma-
1. Clean all starter motor parts. Do not use
ture core or shaft and other lead on commuta-
dissolving agents for cleaning overrunning
tor.
clutch, armature and field coils. Such a
solvent would dissolve grease packed in clutch 2. If meter needle moves, armature is grounded
mechanism and damage armature and field- and must be replaced.
coil insulation.
FIELD COIL TESTS
2. Test overrunning clutch action. Pinion should
turn freely in overrunning direction and must Figures 4-6 and 4-7
not slip in cranking direction. Check pinion
Test For Open Circuit
teeth. Check spring for tension and drive
collar for wear. Replace if necessary. 1. With continuity meter, place one lead on each
end of field coils (insulated brush and field
3. Check that brush holders are not damaged or connector bar) (figure 4-6).
bent and will hold brushes against commuta-
tor. 2. If meter does not move, field coils are open
and must be replaced.
4. Check brushes. Replace if pitted or worn to
one-half their original length (5/16 in. [8 mm] or Test For Ground
less). IMPORTANT: Be sure that positive brushes and
5. Check fit of armature shaft in bushing of drive leads do not contact field frame assembly
housing. Shaft should fit snugly. Replace during test, or false reading will result.
bushing if worn. Apply SAE 20 oil to bushing
1. With continuity meter, place one lead on field
before reassembly. Avoid excessive lubrica-
connector bar and other lead on grounded
tion.
brush (figure 4-7).
2. If meter needle moves, field coils are ground-
ed and must be replaced.

4-4 IES 131 8/98

Starting System SD300 Starter

600-036
22664-012
Figure 4-5 Testing Armature for Short Circuits
Figure 4-7 Testing Field Coil for Grounded
Circuit

LOOSE ELECTRICAL CONNECTIONS

If an open soldered connection of armature-to-
commutator leads is found during inspection, resol-
der it with resin flux.

IMPORTANT: Never use acid flux on electrical

connections.
Turning the Commutator
When inspection shows commutator roughness,
clean as follows:
1. Turn down commutator in a lathe until thor-
oughly cleaned.
2. Recheck armature for shorts as outlined.

22664-011

Figure 4-6 Testing Field Coils for Circuit

IES 131 8/98 4-5

SD300 Starter INDUSTRIAL ENGINE SYSTEMS

STARTER MOTOR ASSEMBLY

Figure 4-8
After all parts are thoroughly tested and inspect-
ed, and worn or damaged parts replaced, reassem-
ble starter as follows:
1. Assemble brushes and related parts to field
frame as follows:
A. Assemble brushes to brush holders.
Attach ground wire to grounded brush
and field lead wire to insulated brush.
B. Assemble insulated and grounded brush
holders together with V-spring. Position
as a unit and install support pin. Push
holders and spring to bottom of support
and rotate spring to engage center of V-
spring in slot of support.
2. Assemble overrunning clutch assembly to
armature shaft as follows (figure 4-8):
A. Lubricate drive end of armature shaft with
SAE 10 oil.
B. Install bearing plate, washer and clutch
assembly onto armature shaft with pinion 22664-013

outward. Figure 4-8 Assembling Overrunning Clutch to

C. Slide retaining collar onto shaft with Armature
cupped surface facing end of shaft away
from pinion. 6. Install through-bolts and tighten securely.
D. Drive snap ring onto shaft and slide down 7. Install solenoid return spring on plunger.
into groove. 8. Position solenoid assembly to starter motor
E. Assemble the thrust collar on shaft with end-frame and turn solenoid to engage flange
shoulder next to snap ring. in slot.
F. Place thrust collar and retaining collar 9. Install screws which hold solenoid assembly to
next to snap ring. Using two pliers, end frame and tighten securely.
squeeze both until snap ring is forced into 10. Install field coil screw and tighten securely.
retainer.
3. Place four or five drops of light engine oil in STARTER MOTOR ADJUSTMENTS
drive housing bushing. Slide armature and
clutch assembly into place while engaging shift Figures 4-9 through 4-11
lever with clutch. Install center bearing attach- Pinion Clearance
ing screws and tighten securely. Pinion clearance must be checked as follows after
4. Position field frame over armature. Carefully reassembly of motor to insure proper adjustment:
apply liquid neoprene between frame and drive
1. Disconnect motor field coil connection from
housing. Use caution to prevent damage to
solenoid motor terminal and insulate it careful-
brushes.
ly (figure 4-9).
5. Place four or five drops of light engine oil in
2. Connect 12-volt battery from solenoid switch
bushing in commutator end frame. Place
terminal to solenoid frame.
washer and commutator end-frame onto shaft.

4-6 IES 131 8/98

Starting System SD300 Starter

22664-014

Figure 4-9 Disconnecting Field Coil From

Solenoid Strap

3. Momentarily touch a jumper lead from solenoid

motor terminal to starter motor frame (figure 4-
10). This shifts pinion into cranking position
where it will remain until battery is disconnect- 22664-015
ed.
Figure 4-10 Shifting Starter Pinion to Check
4. Push pinion back toward commutator end to Clearance
eliminate slack (figure 4-11).
5. Use feeler gages to check clearance between
end of pinion and pinion stop retainer. Clear-
ance should be 0.25 to 4.06 mm (0.010 to
0.160 in.).
6. Disconnect negative (ground) lead from motor
housing (drive pinion will retract into drive end
housing), then disconnect positive lead from
“S” terminal.
7. When clearance is outside specifications,
recheck motor for proper assembly and for
worn or damaged parts in shift mechanism and
drive assembly. Replace worn parts.

22664-016

Figure 4-11 Checking Starter Pinion Clearance

IES 131 8/98 4-7

SD300 Starter INDUSTRIAL ENGINE SYSTEMS

STARTER MOTOR INSTALLATION SOLENOID SWITCH TESTING

1. Place starter motor and solenoid assembly in Figure 4-13
position and install attaching nuts. Torque to
1. Using continuity meter, connect test leads as
specifications.
shown in figure 4-13, and connect 12-volt
2. Fasten wires as outlined in wiring diagram. battery with jumper leads.

SOLENOID REMOVAL 2. If no meter movement is present, replace sole-

noid.
Figure 4-12
1. Disconnect battery cables from battery.
2. Disconnect wires from solenoid terminals.
3. Remove screw from field coil connector and
solenoid attaching screws (figure 4-12).
4. Twist solenoid to disengage tab and remove.

600-039

Figure 4-13 Testing Standard Solenoid, Four

22664-017 Connection Type
Figure 4-12 Field Coil-to-Solenoid Strap Removal

SOLENOID SWITCH INSTALLATION

1. Place plunger spring over plunger. Install sole-
noid onto plunger.
2. Twist solenoid to engage lock tab.
3. Install attaching screws and tighten securely.
4. Install field coil connector screw and tighten
securely.
5. Connect solenoid wires and battery cables.

4-8 IES 131 8/98

Starting System PG260 Starter

PG260 STARTER MOTOR

IDENTIFICATION LUBRICATION
Figure 4-14 Starter motors do not require lubrication except
during overhaul.
The PG260 starter motor can easily be identified
by the 3 Torx® bolts that retain the solenoid to the SOLENOID REPLACEMENT
drive end housing. The starter motor features small
permanent magnets mounted inside the field frame. When a “no crank and no sound” starter condi-
A permanent magnet motor is about half the weight tions exists, check solenoid before disassembling
and size of a field coil motor having the same crank- starter. Solenoid can be checked without removal.
ing performance. The drive housing encloses the Refer to “Cleaning, Inspection and Testing” in this
shift lever, the shift lever mechanism, and the sole- Section. Solenoid can be serviced separately from
noid plunger to protect them from exposure to dirt, the drive and housing. Refer to Starter Motor
icing conditions, and splash. Disassembly and Starter Motor Assembly in this
Section.

7226-200-001A

Figure 4-14 Cross Section of PG260 Starter Motor

IES 131 8/98 4-9

PG260 Starter INDUSTRIAL ENGINE SYSTEMS

STARTER REPLACEMENT Make connections as shown in figure 4-15. Close

the switch and compare RPM, current and voltage
Remove or Disconnect readings with the specifications.
1. Negative battery cable.
If the specified current draw does not include the
2. Bolts to flywheel inspection cover. solenoid, deduct from the armature reading the
3. Starter wiring. specified current draw of the solenoid hold-in wind-
4. Flywheel inspection cover. ing. Make disconnections only with the switch
open. Use the test results as follows:
5. Starter mounting bolts.
1. Rated current draw and no-load speed indi-
6. Starter.
cates normal condition of the starter motor.
Install or Connect
2. Low free speed and high current draw indi-
NOTICE: Before installing starter motor to engine, cates:
tighten inner nuts on solenoid terminals to be sure • Too much friction - tight, dirty or worn bear-
they are secure in cap. Tighten inner nuts on ings, bent armature shaft allowing armature
battery terminal and motor terminal to 10 N•m (88 to drag.
lb. in.). If nuts are not properly tightened, starter • Grounded armature. This can be further
may fail later due to terminal or cap damage. checked on a growler after disassembly.
1. Starter. 3. Failure to operate with high current draw indi-
2. Starter mounting bolts. cates:
Tighten • A direct ground in the terminal.
• Bolts to 30 N•m (22 lb. ft). • “Frozen” bearings.
3. Starter wiring.
Tighten
• Nut on solenoid battery terminal to 8 N•m
(71 lb. in.).
• Nut on “S” terminal to 3 N•m (26 lb. in.).
4. Flywheel inspection cover.
Tighten
• Bolts to 7 N•m (62 lb. in.).
5. Negative battery cable.
Tighten
• Cable bolt to 15 N•m (11 lb. ft.).

NO LOAD TEST
Figure 4-15
With the starter motor removed from the engine,
the pinion should be checked for freedom of rota- 131-162
tion by turning it on the shaft. The armature should
be checked for freedom of rotation by prying the Figure 4-15 No Load Test (Typical)
pinion with a screwdriver. If the armature does not
turn freely, The motor should be disassembled
immediately. However, if the armature does rotate
freely, the motor should be given a no-load test
before disassembly.

4-10 IES 131 8/98

Starting System PG260 Starter

4. Failure to operate with no current draw indi- NOTICE: Before removing, lift each brush spring
cates: and rest against side of brush; this prevents brush
• Open brush circuit. This can be checked damage when assembly is pulled off of commutator.
after disassembly by inspecting internal If springs are allowed to push brushes down when
connections and tracing circuit with a test brush is moved off of commutator, the brush pigtail
lamp. lead may be separated from the brush.
• Open armature coils. Inspect the commuta- 8. Slightly separate gear and drive assembly
tor for badly burned bars after disassembly. from drive end frame and use screwdriver to
pry “plastic” shift lever off drive pins.
• Broken brush springs, worn brushes, high
insulation between the commutator bars or 9. Gear and drive from drive end frame.
other causes which would prevent good 10. Thrust collar from armature shaft, then slide
contact between the brushes and commuta- deep socket over shaft, tap socket to drive
tor. pinion stop collar off retainer ring.
5. Low no-load speed and low current draw indi- 11. Retainer ring and drive from shaft.
cates:
• High internal resistance due to poor connec- CLEANING, INSPECTION, AND
tions, defective leads, dirty commutator and TESTING
causes listed under number 4.
Figures 4-17 and 4-18
6. High free speed and high current draw may
indicate shorted armature, Check for shorted Inspect
armature using a growler. 1. Clean all starting motor parts, but DO NOT
USE GREASE DISSOLVING SOLVENTS
STARTER MOTOR DISASSEMBLY FOR CLEANING THE OVERRUNNING
CLUTCH OR ARMATURE because solvents
Figure 4-16
dissolve the grease packed in the clutch and
Refer to “Specifications” in this section for appli- damage armature insulation.
cation. 2. Test drive assembly action. The pinion should
Remove or Disconnect turn freely in the overrunning direction. Check
1. Lead from solenoid terminal. pinion teeth to see that they have not been
chipped, cracked, or excessively worn.
2. Solenoid retaining bolts. Replace assembly when necessary. Badly
3. Through bolts. chipped pinion teeth can indicate chipped ring
4. Screws and commutator end frame from motor gear teeth, which should be replaced when
assembly (brush assembly and bearing remain necessary.
on armature). 3. The roll type drive assembly acquires no lubri-
cation; however. the drive assembly should be
CAUTION wiped clean. Do not clean in degreasing tank,
or with grease dissolving solvents; this
Magnets in frame have strong attraction to metal dissolves the lubricant in the drive mechanism.
parts. Keep fingers clear of pinch points to avoid 4. Armature commutator. When commutator is
personal injury. dirty, clean with 400 grit polishing cloth. When
commutator is rough, the armature should be
5. Armature from field frame. replaced. Do not undercut or turn commuta-
6. Frame and shield from drive end housing tors. Inspect the points where the armature
assembly. conductors join the commutator bars to make
sure they have a good connection. A burned
7. Use J 28509-A or equivalent to pull bearing
commutator bar is usually evidence of a poor
from armature. The bearing is press fit over
connection.
shaft.

IES 131 8/98 4-11

PG260 Starter INDUSTRIAL ENGINE SYSTEMS

131-153

Figure 4-16 PG260 Starter Motor (Disassembled)

600-036 131-155

Figure 4-17 Testing Armature for Short Circuits Figure 4-18 Testing Solenoid Windings

4-12 IES 131 8/98

Starting System PG260 Starter

5. Brushes and brush holders. When brushes • Current draw readings that are under spec-
are excessively worn when compared to a new ifications indicate excessive resistance. A
brush they should be replaced. Make sure the zero indicates an open. Check/repair
brush holders are clean and the brushes are connections when possible, otherwise
not binding in the holders. The full brush replace starter solenoid.
surface should ride on the commutator to give • The starter solenoid and drive end housing
proper performance. Check to insure that are serviced as an assembly.
brush springs are giving firm contact between
the brushes and commutator. When the STARTER MOTOR ASSEMBLY
springs are distorted or discolored, they should
be replaced. Figures 4-16, 4-19 through 4-21
6. When test equipment is available: Assemble
• Check the armature for short circuits by 1. Lubricate inner gear teeth and bearing, plane-
placing on growler, and holding hack saw tary gears, and armature shaft gear teeth light-
blade over armature core while armature is ly with lubricant. Refer to figure 4-19.
rotated (figure 4-17). If saw blade vibrates, 2. Inner gear and drive over armature shaft with
armature is shorted. Clean between the pinion away from armature.
commutator bars and recheck armature for
3. Pinion stop collar onto armature shaft.
short circuits. If saw blade still vibrates,
replace the armature. 4. New pinion stop retainer ring into groove on
shaft. Do not reuse old ring.
• Using a self-powered test lamp, place one
lead on the commutator and the other lead 5. Thrust collar to end of shaft with small flange
on the armature core or shaft. If the lamp toward retainer ring. Use pliers as shown in
lights, the armature is grounded and must figure 4-20 to snap pinion stop collar over
be repaired or replaced. retainer ring.
7. Check solenoid windings:
• To check hold-in winding, connect an
ammeter and switch in series with a 12-volt
battery and the “switch” terminal on the
solenoid. Connect a voltmeter to the “S”
terminal and to ground. Connect carbon
pile across battery. Adust the voltage to 10
volts and note the ammeter reading. Refer
to figure 4-18.
• PG260 starter motor reading should be 10
to 20 amperes. To check both windings,
connect as for previous test. Ground the
solenoid motor terminal “S.” Adjust the volt-
age to 10 Volts and note the ammeter read-
ing. It should be 60 to 85 amperes for
PG260 motors.
• Current draw readings that are over specifi-
cations indicate shorted turns or a ground in
the solenoid windings. Replace the starter
solenoid.
131-158

Figure 4-19 Armature and Drive Assembly

IES 131 8/98 4-13

PG260 Starter INDUSTRIAL ENGINE SYSTEMS
6. Drive and shaft assembly into drive end hous-
ing. Use a screwdriver to gently guide shift
lever over shift collar pins on drive assembly.

CAUTION
Field frame magnets have strong attraction to
armature. Keep fingers clear of pinch points to
avoid personal injury.

7. Shield, field frame and armature to drive end

housing.
Inspect
• Brushes. When damaged or excessively
worn, replace brush holder assembly.
131-156
8. Brush holder assembly onto armature.
Figure 4-20 Installing Retainer, Washer and Ring
9. Commutator end frame to brush assembly
using screws.
Inspect
Tighten
Drive end housing bearing and armature commu-
tator end bearing. When dry, the armature commu- • Screws to 6.5 N•m (60 lb. in.).
tator end bearing may be lightly lubricated with 10. Through-bolts.
lubricant. Bearing in drive end housing is a roller Tighten
type bearing and is permanently lubricated. DO
NOT ADD LUBRICANT. If dry, replace the drive end • Through-bolts to 8.5 N•m (75 lb. in.).
housing bearing using a small bearing puller; Measure
recessed 0.25 mm (0.01 in.) into casting (figure 4- • Pinion clearance, refer to "Checking Pinion
21). Replace bearings when damaged. Clearance" in this Section.

NOTICE: Before attaching field lead, be sure sole-

noid terminal is secure by tightening nut next to cap.
If this nut is not tight, the cap may be damaged
during installation of the field lead and cause starter
to fail later.
Tighten
• Nut on solenoid field terminal to 8 N•m (71
lb. in.).
11. Solenoid.
12. Field lead to solenoid terminal.
Tighten
• Attaching nut to 8 N•m (71 lb. in.).
131-157

Figure 4-21 Drive End Housing Bearing

4-14 IES 131 8/98

Starting System PG260 Starter

CHECKING PINION CLEARANCE 4. Momentarily ground solenoid terminal “S” to

motor housing. This energizes the solenoid
Figure 4-22 pull-in coil and causes the drive pinion to move
into cranking position. The drive pinion will
CAUTION stay in this position when momentary ground is
removed.
Keep fingers, tools, and other objects away from 5. Press on clutch just enough to take up any free
opening in drive end housing while making elec- pinion movement on the shaft as shown in
trical connections during this procedure. The figure 4-22. Use feeler gages to check clear-
strong shifting action of the solenoid could cause ance between end of pinion and pinion stop
personal Injury or damage as the drive pinion retainer. Clearance should be 0.25 to 4.06 mm
moves into cranking position. (0.010 to 0.160 in).
6. Disconnect negative (ground) lead from motor
1. Secure starter motor in vise or equivalent housing (drive pinion will retract into drive end
fixture so that opening in drive end housing is housing), then disconnect positive lead from
accessible for measurement. “S” terminal.
2. Assure that field lead is disconnected and 7. When clearance is outside specifications,
insulated from solenoid terminal. recheck motor for proper assembly and for
3. Connect positive lead from a 12-volt power worn or damaged parts in shift mechanism and
source to the solenoid “S” terminal. Connect drive assembly. Replace worn parts.
negative lead from power source to clean
ground on motor housing. This energizes
hold-in coil.

131-163

Figure 4-22 Checking Pinion Clearance

IES 131 8/98 4-15

PG260 Starter INDUSTRIAL ENGINE SYSTEMS

TORQUE SPECIFICATIONS
English and Metric Fasteners

CAUTION
Late model engines use a combination of English and Metric threaded fasteners. The components effect-
ed are starter motor, engine mounts, and flywheel housing mounting. Verify that the proper fasteners are
used whenever removing or replacing one of these components.

Mounting Fasteners
Starter Mounting Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 - 45 N•m (26 - 33 lb. ft.)
Flywheel Inspection Cover Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 N•m (11 lb. ft.)
Solenoid “B” Terminal Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.5 N•m (84 lb. in.)
Solenoid “S” Terminal Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 N•m (20 lb. in.)
Solenoid “R” Terminal Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 N•m (20 lb. in.)

Motor Fasteners
Solenoid Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........................ . . . . . 4.5 N•m (40 lb. in.)
Brush Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........................ . . . . . 3.4 N•m (30 lb. in.)
Through Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........................ . . . . . 6.4 N•m (57 lb. in.)
Solenoid “M” Terminal Nut . . . . . . . . . . . . . . . . . . . . . . . . . ........................ . . . . . 6.2 N•m (55 lb. in.)

GENERAL SPECIFICATIONS
Starter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PG260
No Load Test at 11.5 Volts – Current Draw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 - 120 Amps
Pinion Speed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,900 - 3,400 RPM
Solenoid Hold-in Windings at 11.5 Volts – Current Draw. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 15 Amps
Both Windings at 11.5 Volts – Current Draw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 - 50 Amps

4-16 IES 131 8/98

Table of Contents INDUSTRIAL ENGINE SYSTEMS

TABLE OF CONTENTS
General Information..................................................................................................................................5-1

Mando Alternator ......................................................................................................................................5-3

Precautions for Testing Alternator............................................................................................................5-3
Preparing to Check Alternator .................................................................................................................5-3
Test Output Circuit ...................................................................................................................................5-4
Test Excitation Circuit...............................................................................................................................5-4
Test Alternator Current Output .................................................................................................................5-5
Test Voltage Regulator.............................................................................................................................5-6
Remove Alternator ...................................................................................................................................5-6
Disassemble Alternator ............................................................................................................................5-7
Clean and Test Alternator Components...................................................................................................5-9
Assemble Alternator...............................................................................................................................5-12
Install Alternator .....................................................................................................................................5-14
Adjust Alternator Belt .............................................................................................................................5-14

5-i IES 131 8/99

Charging System General Information

GENERAL INFORMATION
This alternator employs a rotor which is support- Voltage output of the alternator is controlled by
ed between two end frames by ball bearings. The regulating the current supplied to the rotor field
alternator is driven by the crankshaft by means of a windings. This is accomplished by a transistorized
V-belt and two pulleys at approximately twice the voltage regulator that senses the voltage at the
engine speed. The rotor contains a field winding battery and regulates the field current to maintain
that is enclosed between two multiple-finger pole the alternator voltage within prescribed limits for
pieces. The ends of the field winding are connected properly charging the battery. The current output of
to two slip rings which are in continuous sliding the alternator does not require regulation, as maxi-
contact with two brushes mounted in the rear end- mum current output is self-limited by the design of
frame. The current flowing through the field winding the alternator. As long as the voltage is regulated
creates a magnetic field that causes the adjacent within the prescribed limits, the alternator cannot
fingers of the pole pieces to become alternate north produce excessive current. A cutout relay in the
and south magnetic poles. voltage regulator is not required either, as the recti-
fier diodes, which allow current to flow in one direc-
A 3-phase stator is mounted directly over the rotor
tion only, prevent the battery from discharging back
pole pieces and between the two end frames. It
through the stator.
consists of three windings arranged at 120° electri-
cally out-of-phase on the inside of a laminated core. Due to the lack of residual magnetism in the rotor
The windings are all connected together on one pole pieces, a small amount of current must be
end, while the other ends are connected to a full- supplied to the rotor field to initially start the alter-
wave rectifier bridge. nator charging. This is accomplished by means of
an excitation, circuit in the regulator which is
The rectifier bridge contains six diodes which are
connected to the ignition switch. Once the alterna-
arranged to allow current to flow from ground,
tor begins to produce output, the field is then
through the stator and to the output terminal, but not
supplied solely by the diode trio.
in the opposite direction.
The alternator is also equipped with a fan, mount-
When current is supplied to the rotor field winding,
ed on the rotor shaft, which induces airflow through
and the rotor is turned, the movement of the
the alternator to remove the heat created by the
magnetic fields induces an alternating current into
rectifier and stator. A capacitor is utilized to protect
the stator windings. The rectifier bridge then
the rectifier system from high voltages and to
changes this alternating current to direct current
suppress radio noise.
which appears at the output terminal. A diode trio
also is connected to the rotor windings to supply
current to the regulator and the rotor field windings
during operation.

IES 131 8/98 5-1

General Information INDUSTRIAL ENGINE SYSTEMS

THIS PAGE WAS INTENTIONALLY LEFT BLANK

5-2 IES 131 8/98

Charging System Mando Alternator

MANDO ALTERNATOR
PRECAUTIONS FOR TESTING WARNING
ALTERNATOR
Keep fingers, clothing, etc. from alternator belts,
fan and pulley; severe bodily harm can occur.

PREPARING TO CHECK
ALTERNATOR
Figure 5-2
Before you start alternator tests, check these
items:
1. If problem is an undercharged battery, check to
ensure that undercharged condition has not
been caused by excessive accessory current
draw or by accessories which have accidental-
22664-086 ly been left on. Also, check that undercharged
condition has not been caused by running
Figure 5-1 Alternator Assembly
engine at too low a speed for extended periods
of time.
2. Check physical condition and state of charge
CAUTION of battery, as outlined under “Battery Hydrom-
eter Test”' in this chapter. Battery MUST BE
1. DO NOT attempt to polarize the alternator.
fully charged to obtain valid results in the
2. DO NOT short across or ground any of the following tests. If not, charge battery before
terminals on the alternator, except as testing system.
specifically instructed in the “Troubleshoot-
3. Inspect entire alternator system wiring for
ing Tests.”
defects. Check all connections for tightness
3. NEVER disconnect the alternator output and cleanliness (figure 5-2), particularly
lead or battery cables when the alternator is battery cable clamps and battery terminals.
driven by the engine.
4. Check alternator drive belt for excessive wear,
4. NEVER disconnect regulator lead from cracks, fraying and glazed surfaces, and
alternator regulator terminal when the alter- replace, if necessary. Also, check drive belt
nator is being driven by the engine. tension and adjust, if necessary, as outlined
5. ALWAYS remove negative (-) battery cable under “Adjust Alternator Belt” in this Section.
from battery before working on alternator
system.
6. When installing battery, BE SURE to
connect the negative (-) (grounded) battery
cable to the negative (-) battery terminal
and the positive (+) battery cable to the
positive (+) battery terminal.
7. If a charger or booster battery is to be used,
BE SURE to connect it in parallel with exist-
ing battery (positive to positive; negative to
negative.
131-050

Figure 5-2 Alternator Wiring Connections

IES 131 8/98 5-3
Mando Alternator INDUSTRIAL ENGINE SYSTEMS

TEST OUTPUT CIRCUIT 4. If reading is between 6.0 and 7.0 volts, rotor
field circuit probably is open. Remove regula-
Figure 5-3 tor and inspect for worn brushes or dirty slip
1. Connect positive voltmeter lead to alternator rings. Replace brushes if less than 6.6 mm
output terminal and negative lead to ground (0.260 in.) long. If brushes and slip rings are
terminal on alternator (figure 5-3). in good condition, disassemble alternator and
test rotor, as outlined under “Clean and Test
2. Wiggle engine wiring harness while observing
Alternator Components” in this chapter.
voltmeter. Meter should indicate approximate
battery voltage and should not vary. If no read- 5. If no reading is obtained, an open exists in
ing is obtained, or if reading varies, check alternator excitation lead or in excitation circuit
alternator-output circuit for loose or dirty of regulator. Disconnect yellow lead from
connections or damaged wiring. regulator. Connect positive voltmeter lead to
yellow lead and negative voltmeter lead to
ground. If voltmeter now indicates approxi-
mate battery voltage, voltage regulator is
defective and must be replaced (figure 5-5). If
no voltage is indicated, check excitation circuit
for loose or dirty connections or damaged
wiring.

22664-088

Figure 5-3 Testing Alternator Output Circuit

TEST EXCITATION CIRCUIT

Figures 5-4 and 5-5
1. Connect positive (+) voltmeter lead to excita-
tion terminal on alternator and negative (-) lead 22664-089

to ground terminal on alternator. Figure 5-4 Testing Exciter Circuit

2. Turn ignition switch to “ON” position and note
voltmeter reading. Reading should be 1.3 to
2.5 volts (figure 5-4).
3. If reading is between 0.75 and 1.1 volts, field
circuit probably is shorted or grounded. Disas-
semble alternator and test rotor as outlined
under “Clean and Test Alternator Components”
in this chapter.

5-4 IES 131 8/98

Charging System Mando Alternator

5. Turn off accessories and reinstall coil high-

tension lead. Start engine and adjust engine
speed to 1500-2000 rpm. Quickly observe
ammeter. Reading should be at least 30 amps
(figure 5-6).
6. If reading is low, stop engine and connect a
jumper lead between alternator output terminal
and indicator light terminal (figure 5-7).
Repeat Steps 4 and 5.
7. If reading is now within specifications, diode
trio is faulty. Disassemble alternator and
replace diode trio, as explained in this chapter.
8. If reading is still to low with jumper lead
connected, perform Voltage Regulator Test to
determine if fault is in regulator or alternator.

22664-090

Figure 5-5 Testing Exciter Lead

TEST ALTERNATOR CURRENT

OUTPUT
Figures 5-6 and 5-7
Perform this test to check if alternator is capable
of producing rated current output, using a 0-55 amp
DC ammeter.
1. Disconnect negative (-) battery cable from
battery.
2. Disconnect orange lead from alternator output
terminal and connect ammeter in series
between lead and output terminal. Connect
positive side of ammeter toward output termi-
nal.
3. Reconnect negative battery cable.
4. Remove coil high-tension lead from distributor
cap tower and ground it to block. Turn on all
22664-091
accessories and crank engine over with starter
motor for 15-20 seconds. Figure 5-6 Alternator Output Test 1

IES 131 8/98 5-5

Mando Alternator INDUSTRIAL ENGINE SYSTEMS
3. If reading is high, check for a loose or dirty
regulator ground lead connection. If connec-
tion is good, voltage regulator is faulty and
must be replaced. Be sure to disconnect
battery cables before attempting to remove
regulator.
4. If reading is low:
A. Stop the engine.
B. Remove Phillips cover screw from regulator
cover (figure 5-9).
C. Remove nut from output terminal and nut
from sensing terminal, and remove jumper
(A).
D. Remove another nut from sensing terminal
and nut from excitation terminal.
E. Remove regulator cover.
F. Temporarily install jumper (A) and all asso-
ciated nuts. Leave jumper (B) installed.
G. Remove plastic plug from side of regulator.
H. Connect a jumper between top brush lead
from brush and ground (figure 5-10).
I. Repeat steps 1 and 2.
22662-092

Figure 5-7 Alternator Output Test 2 NOTICE: DO NOT let voltage exceed 16 volts.
J. If a voltmeter reading of 14.5 volts or above
TEST VOLTAGE REGULATOR is now obtained, voltage regulator is faulty
and must be replaced. If voltmeter reading
Figure 5-8 through 5-10 is below 14.5 volts, inspect brushes and slip
Perform this test to determine if voltage regulator rings for wear, dirt or damage. If brushes
is operating correctly, using a 0-20 volt DC volt- and slip rings are good, alternator is faulty
meter. internally. Disassemble alternator and test
components, as outlined in this chapter.
IMPORTANT: Battery MUST BE fully charged,
1.265 or above specific gravity, to obtain proper REMOVE ALTERNATOR
voltage reading in this test. If necessary, charge
1. Disconnect negative (-) battery ground cable.
battery with a battery charger or allow engine to
run a sufficient length of time to fully charge 2. Disconnect wiring leads.
battery before taking reading. 3. Loosen screws. Holding alternator, rotate
1. Connect positive (+) voltmeter lead to positive alternator towards engine and lift belt off the
battery terminal and negative (-) voltmeter lead pulley.
to negative terminal (figure 5-8). 4. Remove screws and washers to remove alter-
2. Start engine and run at fast idle until engine nator.
reaches normal operating temperature. Adjust
engine speed to 1,500-2,000 rpm and observe
voltmeter for highest reading. Reading should
be between 13.7 and 14.7 volts.

5-6 IES 131 8/98

Charging System Mando Alternator

22662-093 22662-095

Figure 5-8 System Voltage Check Figure 5-10 End View of Regulator with Cover
Removed

DISASSEMBLE ALTERNATOR
Figures 5-11 through 5-17
1. Remove terminal nuts to remove jumper.
2. Remove remaining terminal nuts.
3. Remove capacitor.
4. Remove Phillips screw from regulator cover.
5. Remove brush/regulator assembly cover.
6. Remove nut from terminal.
7. Remove jumper.
8. Remove terminal insulators.
9. Remove two Phillips screws and remove
brush/regulator assembly.
10. Place an oversized V-belt around pulley and
22662-094 fasten pulley in a vise (figure 5-12).
Figure 5-9 Regulator Cover Removed 11. Use a 7/8” box wrench to loosen and remove
pulley nut.
12. Remove the pulley nut, lockwasher, pulley, fan,
and spacer (figure 5-13).

IES 131 8/98 5-7

Mando Alternator INDUSTRIAL ENGINE SYSTEMS
13. Remove four through-bolts and carefully pry
the front housing away from the rear housing
using two screwdrivers (figure 5-14).
14. Carefully push the rotor assembly out of the
front housing and rear housing (figure 5-15).

NOTICE: If bearing is removed from housing, a

new bearing must be installed.
15. After removing the three bearing locking
screws, carefully press the front bearing from
the housing. Press against the inner race of
the bearing as shown (figure 5-16).
16. Remove rectifier assembly by removing
Phillips screw and lifting out assembly (figure
5-17).

22662-097

Figure 5-11 Alternator Disassembly

22662-099

Figure 5-13 Pulley and Fan Components

22662-098

Figure 5-12 Pulley Removal

NOTICE: Score the stator, front and rear housings

so the unit may be reassembled correctly.
22662-100

CAUTION Figure 5-14 Housing and Stator Removal

DO NOT insert screwdriver blades more than 1.6

mm (0.0625 in.). Damage to the stator winding
could result from deeper penetration.

5-8 IES 131 8/98

Charging System Mando Alternator

CLEAN AND TEST ALTERNATOR

COMPONENTS
Figures 5-18 through 5-24
1. Inspect and test brush/regulator assembly.
Brush set may be reused if brushes are 6.6
mm (0.260 in.) or longer. Brushes must not be
oil soaked, cracked or grooved.
Test for continuity between 1 and 2, and 3 and
4 using a test lamp or an ohmmeter (figure 5-
18). These checks will indicate a good
brush/regulator assembly; replace complete
assembly, if necessary.

22662-101

Figure 5-15 Rotor Removal

22662-105

Figure 5-18 Testing Brush/Regulator Assembly

22662-103 2. Inspect and test diode-trio assembly (figure 5-

Figure 5-16 Front Housing Bearing Removal 19).
A. Using a commercial diode tester, a 12-volt
DC test lamp or an ohmmeter, check the
resistance between each of the three diode
terminals and the indicator light stud as
shown.
B. Reverse the tester leads and repeat the
resistance checks.

22662-104

Figure 5-17 Rectifier Removal 22662-106

Figure 5-19 Diode Trio Assembly

IES 131 8/98 5-9

Mando Alternator INDUSTRIAL ENGINE SYSTEMS
C. A very low resistance should be indicated in 5. Clean and inspect rotor shaft bearings (figure
one direction and a very high resistance 5-21):
should be indicated in the other direction if
the diodes are normal. NOTICE: DO NOT use a solvent on rear rotor bear-
ing since it is serviced as a unit with the rotor.
D. If any diode appears to be defective,
replace the complete assembly. Do not A. Bearings should be wiped clean with a lint-
attempt to replace an individual diode. free cloth containing a moderate amount of
3. Test diode-rectifier bridge as follows: commercial solvent. Do not immerse a
bearing in solvent, or use pressurized
A. Using a commercial diode tester, check for solvent or air.
continuity from each of three terminals to
output terminal (figure 5-20). B. Check the bearings for obvious damage,
looseness or rough rotation. Replace a
bearing if any doubt exists as to its condi-
tion.

NOTICE: If the rear rotor bearing needs replace-

ment, replace the entire rotor.
6. Inspect the belt pulley for rough or badly worn
belt grooves or keyway and for cracks or
breaks. Remove minor burrs and correct
minor surface damage; replace a badly worn
22662-107 or damaged pulley.
Figure 5-20 Diode Rectifier Bridge

B. Reverse the tester leads and repeat Step a.

C. Continuity should exist in only one direction
and all diodes should check alike.
D. Perform the same continuity checks
between the three terminals and strap
ground terminal. This should show continu-
ity in only one direction through the diodes
and all diodes should check alike.
E. If any diode appears to be defective,
replace the rectifier assembly.
4. Clean and inspect front and rear housings.
A. Inspect the rear housing for cracks or
breaks in the casting, stripped threads or a
damaged bearing bore. Replace the hous-
ing if any of these conditions exist.
B. Inspect the front housing for cracks,
stripped or damaged threads in the adjust-
ing ear, or an out-of-round bore in the
mounting foot. If possible, correct slightly
damaged threads using a tap. Replace the
housing if necessary.
22662-108
C. If the housings are to be reused, clean them
in solvent and dry with compressed air. Figure 5-21 Alternator Bearings

5-10 IES 131 8/98

Charging System Mando Alternator

7. Test stator windings as follows: C. Minor burning or pitting of the slip ring
A. Using an ohmmeter or test lamp, check for surfaces can be removed using crocus
continuity between all three leads. A low cloth. Thoroughly wipe the slip rings clean
ohm reading or lit test lamp should be after polishing, removing all grit and dust.
observed (figure 5-22). D. Check for a grounded slip ring or rotor wind-
ing by measuring resistance from each slip
ring to the rotor body or pole finger (B). An
open circuit should be indicated in both
cases for a good rotor (figure 5-23).
E. If windings are defective or physical
damage cannot be corrected, replace the
rotor assembly.
9. Use a commercial capacitor checker to test
capacitor for capacity, shorts, leakage, and
series resistance (figure 5-24).

22662-109

Figure 5-22 Stator Windings

B. Check resistance from each lead to the

laminations. There should be no continuity
if the insulation is good.
C. Inspect the stator windings for signs of
discoloration. A discolored winding should
be replaced.
D. If a winding shows a high resistance or an
open circuit between any two of the three
winding terminals, or indicates poor insula-
tion between the windings and the lamina-
tions, the stator must be replaced.
8. Check rotor assembly as follows:

NOTICE: If slip rings need to be replaced, you

must replace the entire rotor.
A. Visually inspect for physical defects such as
damaged shaft threads, worn or damaged
bearing areas, burned or pitted slip rings or
scuffed pole fingers (figure 5-23). 22662-110

B. Measure winding resistance across the slip Figure 5-23 Testing Rotor
rings (A). Place the ohmmeter leads on the
edges of the slip rings, not on the brush
contact surfaces. The correct winding resis-
tance at 70-80°F (21-27°C) is 4.1 to 4.7
ohms (figure 5-23).
22662-111

Figure 5-24 Capacitor

IES 131 8/98 5-11

Mando Alternator INDUSTRIAL ENGINE SYSTEMS

ASSEMBLE ALTERNATOR
Figures 5-25 through 5-32
1. Carefully press the front bearing into the front
housing, pushing against the bearing outer
race using a bearing driver (figure 5-25). Lock
the bearing in place with screws (figure 5-26).
2. Place the rotor (pulley end up) on the bed of an
arbor press, on two steel blocks.
3. Press the front housing and bearing assembly
down onto the rotor shaft. Press against the
bearing inner race only, using a sleeve driver.
Use care to insure that the rotor leads clear the
steel blocks (figure 5-27).
22662-113

Figure 5-27 Installing Front Housing on Rotor

Assembly

4. Install rectifier assembly into rear housing.

5. Insert Phillips screw and tighten.
6. Assemble the front and rear housings as
follows:
A. Put the stator winding in the front housing
with the stator leads away from the front
housing and the notches in the stator lami-
nations aligned with the four through-bolt
22662-112 holes in the housing.
Figure 5-25 Front Bearing Installation B. Align the scribe marks you made in the
stator, front, and rear housings during disas-
sembly.

22662-104

22662-102 Figure 5-28 Installing Rectifier Assembly

Figure 5-26 Installing Bearing Retainers

5-12 IES 131 8/98

Charging System Mando Alternator

C. Slip the rear housing into place over the 14. Install nut on terminal.
rotor shaft. Align the mounting holes and 15. Install brush/regulator assembly cover.
put the stator leads through the holes at the
top of the rear housing. 16. Install Phillips screw for brush/regulator
assembly cover.
D. Install the four bolts and tighten.
17. Install capacitor.
NOTICE: If the front housing is new, the through- 18. Install terminal nuts.
bolt will not be tapped.
19. Install jumper.
20. Install last terminal nut.

22662-099

Figure 5-30 Pulley and Fan Components

22662-114

Figure 5-29 Assembling Housings

7. Install the spacer and the fan. Then push the

pulley, lockwasher and nut onto the shaft
(figure 5-30). Turn nut a few turns.
8. Place an oversized V-belt around pulley and
fasten pulley in a vise (figure 5-31).
9. Use a torque wrench and tighten nut to 95 N•m
(70 lb. ft.).
10. Carefully install the brush/regulator assembly
on the rear housing with the two mounting
screws.
22662-098
11. Install small terminal insulators.
Figure 5-31 Installing Pulley and Fan Nut
12. Install large terminal insulator.
13. Install jumper.

IES 131 8/98 5-13

Mando Alternator INDUSTRIAL ENGINE SYSTEMS

INSTALL ALTERNATOR
1. Install alternator, screws and washers.
2. Connect wiring leads.
3. Install belt on alternator and other pulleys.
4. Adjust alternator belt tension as outlined later
in this Section.

ADJUST ALTERNATOR BELT

1. Loosen mounting-cap screws.

CAUTION
Force must be applied to front alternator housing
only to prevent damaging alternator when belt
tension is adjusted.

2. Pull alternator away from engine to adjust belt

tension to specification at a point halfway
between engine water pump and alternator.
Alternator Belt Deflection: 13 mm (0.50 in.)
22664-097

Figure 5-32 Alternator Assembly 3. Tighten mounting cap screws securely.

4. If new drive belt is installed, check belt tension
again after operating for 5 minutes.

5-14 IES 131 8/98

Table of Contents INDUSTRIAL ENGINE SYSTEMS

TABLE OF CONTENTS
General Information .................................................................................................................................6-1
Conventional Ignition Systems.................................................................................................................6-1
High Energy Ignition Systems..................................................................................................................6-1
Electronic Spark Timing (EST) Distributor ...............................................................................................6-8
Spark Plug Wires ...................................................................................................................................6-10
Spark Advance Curves ..........................................................................................................................6-11

Delco Electronic Spark Timing (EST) Distributor Service .................................................................6-15

General Description ...............................................................................................................................6-15
EST Distributor Component Testing ......................................................................................................6-15
EST Distributor Removal .......................................................................................................................6-17
EST Distributor Disassembly .................................................................................................................6-17
Cleaning and Inspection ........................................................................................................................6-17
EST Distributor Reassembly..................................................................................................................6-17
EST Distributor Installation - Engine Not Disturbed...............................................................................6-18
EST Distributor Installation - Engine Disturbed .....................................................................................6-18
Ignition Timing - EST System ................................................................................................................6-18

Delco High Ignition (HEI) Distributor Service......................................................................................6-21

General Description ...............................................................................................................................6-21
HEI Distributor Removal ........................................................................................................................6-21
Disassembly, Testing, and Reassembly.................................................................................................6-21
HEI Distributor Installation - Engine Not Disturbed................................................................................6-24
HEI Distributor Installation - Engine Disturbed ......................................................................................6-24
Ignition Timing - HEI Distributor .............................................................................................................6-25

6-i IES 131 8/99

Ignition System General Information

GENERAL INFORMATION
CONVENTIONAL IGNITION SYSTEMS HIGH ENERGY IGNITION SYSTEMS
The conventional breaker point system met the Figures 6-1 through 6-10
requirements placed on the ignition system for
The High Energy Ignition System (figure 6-1) has
many years. It provided sufficient voltage to the
undergone many improvements since its introduc-
spark plug to cause a spark across the air gap of
tion. The system is an electronic system that
sufficient intensity to ignite the air/fuel mixture in the
requires no scheduled maintenance, provides up to
combustion chamber. It timed the spark to arrive at
35,000 volts to fire the spark plugs and increases
the correct cylinder at the proper moment in the
spark plug life. The system has 40% more voltage
compression stroke of that cylinder. It also could
output and 85% higher energy level than the
vary the time the spark arrived at the cylinder in
conventional breaker point system to fire lean fuel
relation to engine speed and load to achieve maxi-
mixtures even under the most adverse conditions.
mum power and economy from the engine.
Two different distributors are used in the High
These are still the requirements of an ignition
Energy Ignition system. The ‘HEI’ Distributor has
system but the voltage and energy needed to
an integrally mounted coil in the cap while the ‘EST’
complement modern engine operation increased
Distributor is generally smaller and uses a sepa-
beyond the capabilities of the conventional system
rately mounted coil. Distributor design differences
under some operating conditions due to leaner gas
will be detailed later in this Section.
mixtures, and plug erosion. Adverse operating
conditions can vary from cold or wet weather start-
ing an ignition system or spark plugs that are in Module
need of maintenance. The system uses an electronic module and a
Higher secondary voltage could be obtained by magnetic pulse generator to control primary circuit
simply increasing the current in the primary circuit. current (figure 6-2). The electronic module has
several integrated circuits that contain resistors,
By reducing the resistance in the primary circuit, transistors, diodes and capacitors. These circuits
the current would be increased giving a higher- and components are small enough to allow the
secondary voltage. Unfortunately the breaker module to be mounted inside the distributor.
points were already operating at the maximum
current they could handle. The ability of the module to turn the primary
current on and off is due to the transistor. A tran-
In most breaker point systems, the primary circuit sistor is an electrical device that is used to control
operates on 3.5 to 4.0 amperes depending on current flow like a mechanical switch except that it
temperature. This current value in itself is a trade- is turned on and off by electrical current and has no
off between contact point life and system output. moving parts.
Maximum point life is realized at approximately one
ampere. As current is increased from one ampere,
Pulse Generator
point life decreases steadily until just over a current
of 4 amperes is reached. As the current is Since a transistor is turned on and off by electrical
increased above this value, point life begins to current, a properly timed electrical pulse will control
decrease at an increased rate, giving a very limited the primary current in the ignition system. The
point life. This means that more maintenance magnetic pulse generator, or magnetic pickup
would be needed to keep the system operating at assembly, consists of a permanent magnet and a
its best without reduced spark energy. pickup coil. Both are sandwiched between a pole
piece with internal teeth and a bottom plate and
What was needed was a system that did not use
held together by three screws (figure 6-3). The
breaker points to control primary current flow. The
bottom plate then fits over a bushing which is
replacement for the breaker points must be able to
installed in the distributor housing.
carry a current greater than 4 amperes and require
little or no maintenance. Electronics was the
answer.

IES 131 8/99 6-1

General Information INDUSTRIAL ENGINE SYSTEMS

131-057

Figure 6-1 Integral HEI Distributor

131-058

Figure 6-2 Module and Pulse Generator

131-059

Figure 6-3 Pulse Generator Construction

6-2 IES 131 8/99

Ignition System General Information

Magnetic Flux Path At this point, the magnetic field is at its strongest.
As the teeth move apart, the air gap increases and
A timer core on the main shaft of the distributor
the magnetic field decreases until the teeth begin to
has external teeth which align with an equal number
move back together.
or pole piece teeth.
Applying the principle of electromagnetic induc-
The magnetic pickup assembly, by the varying
tion which states that a voltage will be induced in a
magnetic field around the pickup coil, produces an
conductor whenever a magnetic field is moved so
electric current in the pickup coil by electromagnet
that its lines of force (flux) cut across a conductor.
induction. As the timer core rotates past the pole
During the strengthening and weakening of the
piece, the air gap between timer core and pole
magnetic field, the lines of force cut across the pick-
piece teeth varies. Since air is not a good path for
up coil inducing a voltage in the coil.
magnetic flux to travel through, the magnetic field is
relatively weak when the teeth are not aligned. As The principle of electromagnetic induction also
the timer core rotates, the teeth move closer togeth- states that the polarity of the induced voltage
er, the air gap decreases and the magnetic field depends on which side of the conductor is striking
increases until the timer core teeth and pole piece the magnetic lines first. This means that the voltage
teeth are aligned (figures 6-4 and 6-5). induced by a strengthening or expanding magnetic
field will be of the opposite polarity of a voltage
induced by a weakening or collapsing magnetic
field.
This signal is used to turn on and off the transis-
tors in the module that controls the current in the
primary circuit. With one exception, which will be
covered later, the pole piece has the same number
of teeth as the engine has cylinders. This gives the
correct number of “firing” pulses per distributor shaft
rotation.
We have eliminated the contact points and break-
er cam by using a pulse generator to time the turn-
131-060 ing on and off of the primary circuit. In place of the
breaker cam and points, transistors are used to turn
Figure 6-4 Magnetic Flux Path
the current on and off. The wear of the rubbing
block and contact points has been eliminated as
has the current limitations of the contact points.

Current Limiting Circuit

In the past, the transistor was made to operate at
a value less than its maximum to protect it from
transient voltage and electrical current extremes.
These extremes are of short duration but of great
magnitude and can be endured by electromechani-
cal devices like switches, motors and contacts with-
out permanent damage. But for electronic devices,
even a few milliseconds (thousandths of a second)
131-061 exposure to voltage and current above its maximum
Figure 6-5 Magnetic Field Strength Variation capability may cause failure. By designing the
system with enough resistance so that these
extremes are within the capabilities of the electron-
ic devices used, these failures were avoided. This
is why no available voltage gain was achieved.

IES 131 8/99 6-3

General Information INDUSTRIAL ENGINE SYSTEMS
To eliminate this problem, a current limiting circuit When the contact points close, the current does
was added to the HEI module to limit primary not instantaneously reach a value of 4 amperes but
current to 5.5 amperes rather than using resistance. it takes several milliseconds for this value to be
This feature allows the electronic device to operate reached (figure 6-6). At 1000 engine RPMs, the
at their maximum value. Since the HEI circuit distributor shaft rotates once every 0.12 second. Of
current is not limited by circuit resistance, the resis- this time, the points are closed for 0.010 second or
tance wire was eliminated from the system. 10 ms for every cylinder of an eight cylinder engine.
This is sufficient time for the primary current to build
Dwell Control Circuit up to its maximum current of just over 4 amperes.

For the ignition coil to put out maximum When engine speed is increased to 2000 RPM,
secondary voltage, the maximum primary current the time the points are closed for each plug firing is
must be reached before the primary circuit is reduced to 5 ms. A duration of 5 ms allows the
broken. In the breaker point system the length of primary current to build to 3.8 amperes. At an
time the primary current is “ON,” is controlled by the engine speed of 3000 RPM, the duration time drops
speed of the breaker cam. This period is called to 3.3 ms and the current to 3.2 amperes.
“dwell angle” and is given in the number of degrees Two features were incorporated in the HEI system
of distributor shaft rotation. Most V-8 engines have to give it a higher energy level at higher engine
a dwell angle of 30 degrees before the points open speeds.
and fire the cylinder. This dwell angle remains the
same regardless of engine speed but as engine First, by decreasing the resistance in the primary
speed increases, the time the points are closed circuit, the time needed for the current to reach its
decreases. This causes available voltage and coil maximum is greatly reduced. It takes 10 ms for the
energy to decrease as engine speed increases due current to reach maximum in a coil that has a resis-
to the reduced saturation time of the ignition coil. tance of 2.6 ohms. In the HEI system, the primary
winding has a resistance of 0.5 ohms. This allows
full current to be reached in about 3.4 ms.

131-062

Figure 6-6 Current vs. Time

6-4 IES 131 8/99

Ignition System General Information

Because it takes less time to reach full current, Ignition Coil

coil saturation can be obtained at much higher
So far we have only talked about the magnetic
engine speeds. Also, since the current is much
pickup assembly and the module's role in greater
higher in the HEI system, heat generation must be
available voltage and energy, but the design and
controlled so the module can live. This is done by
construction of the ignition coil also affects the
the dwell control circuit in the module. What this
system's output.
circuit does is electronically sense the primary
current to see if maximum current was reached in The design requirements for the HEI coil was that
the last dwell period. If maximum current was it would have a low primary resistance for reasons
reached and no current limiting took place, the we have already covered and have a size and
dwell period will remain the same. If current limiting shape that may be mounted in the distributor cap.
did take place, the dwell period will be shortened by
The primary resistance was decreased by reduc-
turning on the primary circuit later. Since the turn-
ing the length of wire used in the primary windings.
ing off of the circuit is always at the same time, the
Resistance of a wire is determined by its length and
dwell period is shorter. If maximum primary current
diameter. As length increases, resistance increas-
is not reached, the primary circuit is turned on soon-
es and as diameter increases, resistance decreas-
er giving a greater dwell period allowing maximum
es. So by reducing the length of the wire used in
current to be reached.
the primary winding, low resistance is possible with
By using this circuit, the HEI system is able to put a reasonable wire diameter. In the oil-filled ignition
out 35,000 volts to speeds above 3000 engine RPM coil used with conventional ignition systems, the
while the conventional ignition system's maximum primary winding is wrapped around the secondary
voltage is reached about 1000 engine RPM and winding and the secondary winding is wrapped
then begins to fall off. Also, by using dwell control around the iron core (figure 6-7). The HEI coil has
to reduce the time that the current limiting is taking the secondary winding wrapped around the primary
place, the operating temperature of the system Is winding and the primary winding is wrapped around
reduced, further increasing the reliability and life of the iron core. The HEI coil is not oil filled, the wind-
the HEI system. ings are covered in an epoxy compound for protec-
tion against moisture and arc-over within the coil.

131-063

Figure 6-7 HEI and Conventional Ignition Coil Construction

IES 131 8/99 6-5

General Information INDUSTRIAL ENGINE SYSTEMS
The inductance values of the primary and The higher voltage output of the HEI system
secondary winding are also different in the HEI coil. required new insulation materials. To prevent igni-
Inductance of a coil is the ability of the coil to induce tion failure due to carbon tracking, a special mater-
a counter-voltage while carrying an increasing or ial is used for the distributor cap and rotor. It is a
decreasing current (self-induction). This counter- thermoplastic, injection-molded, glass-reinforced
voltage works against the changing current trying to polyester. This material provided the dielectric and
keep the current wire from changing and is a limit- insulation properties needed and also prevented
ing factor on the maximum output of a coil. The carbon tracking.
increased secondary inductance provides a higher
The high voltage terminals used in the distributor
voltage and a longer spark duration than the
cap are similar in appearance to spark plug termi-
conventional system.
nals. These connections provide easier attachment
The HEI system was developed as an integrated and better sealing of the connection.
package that combines the distributor, magnetic
pickup, ignition coil and electronic module into one Centrifugal and Vacuum Advance
package. By doing this, these components are
well-protected from physical and environmental HEI distributors use a combination of centrifugal
abuses and the number of electrical connections advance and vacuum advance systems. These
are reduced. systems operate in much the same way they did on
the conventional distributor, compensating for
There are some models that use a remotely engine speed and load. This is done so that maxi-
mounted coil. This coil is constructed the same as mum pressure is exerted on the top of the piston as
the integral coil with the exception of a mounting soon as the rod passes top dead center.
bracket and a terminal for the connection of a high
tension lead. The weights in the centrifugal advance move
against spring tension as engine speed increases.
The size of the distributor was increased due to This motion of the weights turns the timer core
the wide spacing that must exist between the assembly so that the timer core is rotated in the
distributor cap inserts to prevent high-voltage arc- direction of shaft rotation (figure 6-9). The teeth on
over (figure 6-8). A wider spacing was also needed the timer core will now align with the pole piece
between the cap inserts and the distributor housing teeth sooner, signaling the module to “fire” sooner.
to prevent arc-over and leakage to ground.

131-064

Figure 6-8 Cap Size

131-065

Figure 6-9 Centrifugal Advance

6-6 IES 131 8/99

Ignition System General Information

The vacuum advance uses engine vacuum to

move a spring loaded diaphragm which is connect-
ed by a connecting rod to the bottom plate of the
magnetic pickup assembly. The magnetic pickup
assembly is mounted over the main bearing on the
distributor housing so it is able to rotate. When a
vacuum signal is applied to the diaphragm it moves
against spring pressure pulling the connecting rod
with it. This movement causes the magnetic pickup
assembly (pole piece) to rotate in the opposite
direction of the distributor shaft (timer core) rotation
(figure 6-10). This causes the pole piece teeth to
align sooner with the timer core teeth signaling the
module to “fire” sooner.

131-067

Figure 6-11 Pickup Coil

Part Identification
As stated earlier, there are minor differences
between applications to tailor the HEI system to
each engine. Besides the physical differences
necessary to mount the distributor to the various
engines, there are different ignition coils and differ-
ent pickup coils used.

Pickup Coil
131-066
The pickup coil is not serviced separately but as
Figure 6-10 Vacuum Advance an assembly with the bottom plate, pole piece and
permanent magnet. This assembly, called the “pole
piece and plate” in the parts book, should not be
HEI MODELS disassembled because the pole piece is centered
There are two basic HEI distributors used. One around the axis of the distributor shaft during
has an integral ignition coil mounted in the distribu- production. This sets the clearance between the
tor cap. This model is used on V-8 engines. The teeth of the pole piece and timer core.
second type HEI distributor uses a remotely mount- There are different pole pieces and plate assem-
ed ignition coil (outside of the distributor) which is blies available. The correct part number of the pole
similar in appearance to the coil used with the inte- piece and plate assembly for a particular engine
gral unit. Since the ignition coil is not mounted should be determined from the appropriate parts
inside the distributor, these units are smaller and book. The part number of a pole piece and plate
use a few more wires to connect the ignition coil to assembly can be determined by visual inspection
the distributor. by the colored ties or connectors and the number of
The number of teeth on the pole piece and timer teeth on the timer core and pole piece.
core reflects the number of cylinders in the engine
that it is to be used on (four teeth for four cylinders
and six teeth for six cylinders [figure 6-11]).

IES 131 8/99 6-7

General Information INDUSTRIAL ENGINE SYSTEMS
Coil Identification ELECTRONIC SPARK TIMING (EST)
One type of coil is used for remote coiI applica- DISTRIBUTOR
tions (figure 6-12) with EST distributors. The
Figures 6-14 and 6-15
remote coiI can be easiIy identified by its mounting
brackets and the high tension terminal. An improved ignition coil and distributor system is
used with 3.0L through 7.4L engines (figure 6-14).
The 80 mm (3.15 in.) distributor and high efficiency
ignition coil are smaller in size and lighter in weight.
Reliability was increased while maintaining the high
energy performance and functions of a larger
component. The inherent reliability of the new
distributor is enhanced through simplicity of design
by eliminating all moving parts (except distributor
shaft and rotor. It provides multifunction compo-
nents wherever possible and uses weatherproof
connectors at the electrical interfaces.
The high energy ignition coil is more compact,
lighter in weight, and is designed for remote mount-
ing. The size and weight reduction was possible by
using new lamination material that allowed a
131-070
substantial reduction in the cross-sectional area
without compromising performance.
Figure 6-12 Remote Ignition Coil
As the timer core turns inside the magnetic pick-
up, its triangular points pass very close to the
The other type of coil mounts integrally within the
magnet's points. When this happens, a small volt-
distributor cap (figure 6-13).
age is generated and sent to the HEI module (figure
6-15).
The voltage signal coming from the pickup coil is
alternating current. The microprocessor, however,
will not work with alternating current. Hence, the
module contains a converter that changes the volt-
age to direct current and a square wave.
HEI eliminates the point set to keep better pace
with engine speed. HEI will not wear or change
timing, and it provides more voltage to the spark
plugs.

131-071

Figure 6-13 Internal Ignition Coil

6-8 IES 131 8/99

Ignition System General Information

131-073

Figure 6-14 Distributors and High Energy Ignition Coil

131-074

Figure 6-15 HEI Ignition System (4-Terminal)

IES 131 8/99 6-9

General Information INDUSTRIAL ENGINE SYSTEMS

SPARK PLUG WIRES Resistance Testing

General Description 1. Disconnect both ends of ignition cable (rotate
boot and pull at the boot only) being tested and
The spark plug wires are a carbon-impregnated clean terminals.
cord conductor encased in an 8 millimeter diameter
2. Set ohmmeter on high scale and connect
silicone rubber jacket. Silicone wiring will withstand
ohmmeter to each end of cable being tested.
very high temperature and is an excellent insulator
Twist cable gently while observing ohmmeter.
for the higher voltages.
3. If ohmmeter reads above 25,000 ohms or
Silicone is soft, pliable, and therefore, more
flucuates from infinity to any value, replace
susceptible to scuffing and cutting. It is extremely
cable being tested.
important that the spark plug cables be handled
with care. They should be routed so as not to cross 4. If the resistance of each cable is not within the
each other, or be in contact with, other parts of the following bands, replace the cable being test-
engine to prevent rubbing. ed.
0 to 15 inch cable 3,000 / 10,000 Ohms
NOTICE: For proper operation, it is necessary to 15 to 25 inch cable 4,000 / 15,000 Ohms
keep ignition wires and distributor clean and free of
any dirt or corrosion. 25 to 35 inch cable 6,000 / 20,000 Ohms

6-10 IES 131 8/99

Ignition System General Information

SPARK ADVANCE CURVES

Figures 6-16 through 6-21

131-051

Figure 6-16 Spark Advance Curve - 3.0L Engine Distributor # 7241750 / Ignition Module # 7141680

131-052

Figure 6-17 Spark Advance Curve - 4.3L Engine Distributor # 7244010 / Ignition Module # 7143110

IES 131 8/99 6-11

General Information INDUSTRIAL ENGINE SYSTEMS

131-053

Figure 6-18 Spark Advance Curve - 4.3L Engine Distributor # 7242830 / Ignition Module # 7242130

131-054

Figure 6-19 Spark Advance Curve - 5.7L Engine Distributor # 7242330

6-12 IES 131 8/99

Ignition System General Information

131-055

Figure 6-20 Spark Advance Curve - 5.7L & 7.4L Engine Distributor # 7243190 / Ignition Module
# 7243110

131-056

Figure 6-21 Spark Advance Curve - 7.4L Engine Distributor # 7241260

IES 131 8/99 6-13

General Information INDUSTRIAL ENGINE SYSTEMS

THIS PAGE WAS INTENTIONALLY LEFT BLANK

6-14 IES 131 8/99

Ignition System EST Distributor Service

DELCO ELECTRONIC SPARK TIMING (EST)

DISTRIBUTOR SERVICE
GENERAL DESCRIPTION EST DISTRIBUTOR COMPONENT
Figure 6-22 TESTING
The Delco EST ignition system consists of the Figures 6-23 through 6-26
distributor, ignition coil, wiring and spark plugs. The NOTICE: In the test procedures that follow, check
distributor contains a module, pickup coil and the ignition coil and each component of the distrib-
conventional cap and rotor. There are no points or utor separately to identify defective or good compo-
condenser to adjust or change and no moving parts nents. These tests can be made with the distribu-
except for the distributor shaft and rotor. Spark tor and coil mounted on the engine or on the repair
advance and dwell are controlled by the distributor bench.
module. The distributor module and pickup coil are
self-contained solid-state devices which are not
Module Testing
repairable. If necessary, they may be replaced
separately but must be serviced as a complete unit. NOTICE: An approved module tester must be used
in order to check the module. Use a Kent-Moore
Module Tester, Part No. J 24642 F or equivalent.
1. Remove module from distributor.
2. Connect red battery-cable clamp to positive (+)
terminal and black battery-cable clamp to
negative (-) terminal of a fully charged 12V
battery.
3. Connect J 24642-85 adapter to yellow 2-way
terminal connector, and J 24642-85 adapter to
black 3-way connector of the tester (figure 6-
23).

600-058

Figure 6-22 Delco Electronic Spark Timing (EST)

Distributor

22664-018

Figure 6-23 Test 1 Tester Connections

IES 131 8/99 6-15

EST Distributor Service INDUSTRIAL ENGINE SYSTEMS
4. Connect black 4-way and 2-way connectors to Pickup Coil Testing
module terminals. Connect yellow 2-way
1. Remove the distributor cap and rotor.
connector to yellow module terminals and
engage locking tabs. 2. Disconnect the pickup coil leads from the
module.
5. Connect module ground clip of the tester to the
metal base of the module. 3. Connect an ohmmeter between the pickup coil
lead and housing (test 1, figure 6-25). Read-
6. Hold the toggle switch in the 3-terminal test
ing should be infinite (no continuity).
position. If a momentary indication of the red
“Fail” light and then a steady indication of the 4. Connect an ohmmeter to both pickup coil
green “Pass” light occurs, go on to the next leads (test 2, figure 6-25). Reading should be
step. If a steady indication of the red “Fail” a constant, unchanging value between 500-
light occurs, the module is defective and 1500 ohms. Flex leads by hand at coil and
should be replaced. connector to locate intermittent opens.
Replace pickup coil if not within specifications.
7. Disconnect black 4-way connector from
module. Disconnect yellow 2-way connector,
rotate it 180 degrees so the lock and tab are
opposite each other, and reconnect it to the
module terminals (figure 6-24).
8. Hold the toggle switch in the 3-terminal test
position. A momentary indication of the red
“Fail” light and then a steady indication of the
green “Pass” light means the module is good.
A steady indication of the red “Fail” light means
the module is defective and should be
replaced.

600-060

Figure 6-25 Testing Pickup Coil

Ignition Coil Testing

1. Connect ohmmeter between “B+” or “C-” termi-
nals and ground (coil bracket). On high scale,
reading should be infinite (test 1, figure 6-26).
2. Connect ohmmeter between “B+” and “C-”
terminals. On low scale, reading should be
nearly zero (approximately 0.4 ohm) (test 2,
figure 6-26).
3. Connect ohmmeter between “B+” or “C-” termi-
nals and coil high-voltage tower. On high
scale, reading should be approximately 8000
22664-019
ohms. Reading should not be infinite (test 3,
Figure 6-24 Test 2 Tester Connections figure 6-26).

6-16 IES 131 8/99

Ignition System EST Distributor Service

EST DISTRIBUTOR DISASSEMBLY

NOTICE: Do not disassemble distributor unless
necessary. When disassembling distributor, use
soft wood blocks to hold it in a vise.
1. Remove rotor from distributor shaft.
2. Remove module by detaching leads and
removing two mounting screws.
3. Place a mark on the distributor gear in line with
rotor segment so reassembly can be made in
same location.
4. Drive pin from gear. Remove gear and shaft
assembly.
5. Pry off upper retainer and remove pickup coil.

CLEANING AND INSPECTION

1. Wash housing, gear, and shaft in cleaning
solvent.
2. Inspect housing, gear, and shaft for wear.
Replace if worn.
600-061
3. Inspect wires and connector on pickup coil.
Figure 6-26 Testing Pickup Coil
Replace if damaged.

NOTICE: On tests 2 and 3, reading may vary EST DISTRIBUTOR REASSEMBLY

slightly depending on coil temperature.
1. Install pickup coil and retainer.
4. If reading is not within specifications, replace
coil. 2. Install shaft assembly, two thrust-washers,
gear, and roll pin.
EST DISTRIBUTOR REMOVAL 3. Spin shaft to insure that teeth do not touch.
1. Remove distributor cap (2 screws). Do not 4. Clean module mounting surface of old silicone
remove plug wires from cap unless necessary. grease. Apply clean silicone grease between
housing and module. Silicone grease is
2. Disconnect distributor primary leads at coil. necessary for proper heat dissipation.
3. Crank or turn engine slowly. Align timing 5. Install module and two mounting screws.
marks when rotor is pointing to No. 1 terminal
of distributor cap. If same distributor is to be 6. Attach wires from pickup coil to module.
reinstalled in engine, mark position of distribu- 7. Install rotor onto shaft.
tor housing in relation to engine so that distrib-
utor may be installed in same position.
4. Remove distributor retaining clamp.
5. Remove distributor.

NOTICE: To simplify distributor installation, do not

turn crankshaft with distributor removed from
engine.

IES 131 8/99 6-17

EST Distributor Service INDUSTRIAL ENGINE SYSTEMS

EST DISTRIBUTOR INSTALLATION -

ENGINE NOT DISTURBED
Figure 6-27
1. Install distributor shaft into engine, aligning
marks made at time of removal (figure 6-27).
Be sure that shaft engages oil pump.
2. Secure distributor with clamp.
3. Install distributor cap.

IMPORTANT: Set engine timing with timing

light. Refer to Specifications and to the proce-
dures in this section.

EST DISTRIBUTOR INSTALLATION -

ENGINE DISTURBED
Figure 6-27
1. Rotate engine (in normal direction of rotation)
until timing mark on torsional damper (or
flywheel) lines up with TDC on timing tab and
engine is in No. 1 firing position.
2. Install distributor into engine so that the rotor is
aligned with No. 1 spark plug tower on distrib-
utor cap (figure 6-27).
3. Secure distributor with clamp.
4. Install distributor cap.

IMPORTANT: Set engine timing with timing 600-062

light. Refer to Specifications and to the proce-
Figure 6-27 Distributor Installation
dures in this section.

IGNITION TIMING - EST SYSTEM 1. Connect the timing light to the No. 1 spark plug
(figure 6-28). Connect the power-supply leads
Figures 6-28 through 6-31 of the light to 12V battery.
The following procedure is used to check and 2. Change the timing plug to the “TIME” position
adjust initial spark timing for the EST system: (figure 6-29).

IMPORTANT: In order to set the timing correct- NOTICE: When the BROWN lead from plug
ly, it is necessary to lock out the automatic elec- connected to distributor housing is in line with the
tronic spark-advance feature. This is done PURPLE/WHITE (T) lead or with the label (TIME),
using the timing connector plug which is the electronic spark advance is disabled and the
attached to the distributor. This two-pronged initial spark timing can be checked and adjusted at
connection is marked as shown. this point if necessary.
3. Start engine and run at 1,200 rpm.
CAUTION 4. Aim timing light at timing tab or timing marks
located at the crankshaft balancer (figures 30
Failure to place the timing plug back to the “run” or 31).
position after timing the engine will cause lack of
power and high fuel consumption.

6-18 IES 131 8/99

Ignition System EST Distributor Service

131-088

Figure 6-28 Firing Order

22822-012

Figure 6-29 Timing Plug

143-015

Figure 6-31 Engine Timing Marks

5. Loosen the distributor hold-down clamp and

rotate the distributor body until the timing mark
on the balancer, or pulley, lines up with the
mark on the timing tab. Tighten clamp and
recheck timing.
6. Stop the engine and remove the timing light.
7. Switch the timing plug to the “RUN” position.

NOTICE: When the BROWN lead connected to

distributor housing is in line with the BLACK (R)
lead or with the label (RUN), the electronic spark
advance is functioning and this is the normal oper-
ating mode.
600-262

Figure 6-30 Engine Timing Tab

IES 131 8/99 6-19

EST Distributor Service INDUSTRIAL ENGINE SYSTEMS

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6-20 IES 131 8/99

Ignition System HEI Distributor Service

DELCO HIGH ENERGY IGNITION (HEI)

DISTRIBUTOR SERVICE
GENERAL DESCRIPTION HEI DISTRIBUTOR REMOVAL
Figure 6-32 1. Remove distributor cap (4 screws). Do not
remove plug wires from cap unless necessary.
The Delco High Energy Ignition (HEI) distributor
comes equipped with the ignition coil mounted in 2. Disconnect distributor primary leads at coil.
the cap. The distributor contains a pickup coil, 3. Crank or turn engine slowly. Align timing
centrifugal advance mechanism and rotor. Some marks when rotor is pointing to No. 1 terminal
distributors are also equipped with vacuum of distributor cap. If same distributor is to be
advance units to assist in correcting the spark curve reinstalled in engine, mark position of distribu-
for changing load conditions. There are no points tor housing in relation to engine so that distrib-
or condenser to adjust or change. Spark advance utor may be installed in same position.
and dwell are controlled by the distributor module 4. Remove distributor retaining clamp.
and centrifugal advance. The distributor module
and pickup coil are self-contained solid-state 5. Remove distributor.
devices which are not repairable. If necessary, they
NOTICE: To simplify distributor installation, do not
may be replaced separately but must be serviced
turn crankshaft with distributor removed from
as a complete unit. A typical HEI distributor with
engine.
coil in cap is shown in figure 6-32.
DISASSEMBLY, TESTING, AND
REASSEMBLY
Figures 6-33 through 6-41
1. Detach wiring connector from cap.
2. Turn 4 latches and remove cap and coil
assembly from lower housing.
3. Check ignition coil with ohmmeter for opens or
grounds (figure 6-33):
• Test 1 - Use low scale. Should read zero or
nearly zero. If not, replace coil (refer to step
7).
• Test 2 - Use high scale and connect
ohmmeter both ways. Replace coil only if
both readings are infinite (refer to step 6).
4. If coil is good, go to step 12.
5. Remove coil cover attaching screws and lift off
cover.
6. Remove ignition coil attaching screws and lift
coil with leads from cap (figure 6-34).
7. Remove ignition coil arc seal (figure 6-35).
8. Clean cap with soft cloth and inspect for
defects. Replace cap if necessary.
9. Assemble new coil and cover to cap.
7226-200-002
10. Remove rotor and pickup coil leads from
Figure 6-32 Delco High Energy Ignition (HEI) module.
Distributor

IES 131 8/99 6-21

HEI Distributor Service INDUSTRIAL ENGINE SYSTEMS

7226-200-005

Figure 6-35 Ignition Coil Removed From Cap

7226-200-003

Figure 6-33 Testing Ignition Coil

7226-200-006

Figure 6-36 Testing Pickup Coil

13. Flex leads by hand without vacuum to check

for intermittant opens.
7226-200-004
• Test 1 - Should read infinite at all times.
Figure 6-34 Ignition Coil Attaching Screws • Test 2 - Should read steady at one value
within 500 - 1500 ohm range.
11. Connect ohmmeter, perform test 1, and then
test 2 (figure 6-36). NOTICE: Ohmmeter may deflect if operating vacu-
12. If vacuum unit is used, connect vacuum source um unit causes teeth to align. This is not a defect.
to it. Observe ohmmeter throughout vacuum 14. If pickup coil is defective, go to step 17. If OK,
range. Replace unit if inoperative. go to step 22.
15. Mark distributor shaft and gear so they can be
reassembled in the same position.

6-22 IES 131 8/99

Ignition System HEI Distributor Service

16. Drive out roll pin (figure 6-37). 20. Remove two module attaching screws and
17. Remove gear and pull shaft assembly from the capacitor attaching screw. Lift module, capac-
distributor. itor, and harness assembly from base (figure
6-40).
18. Remove three attaching screws and remove
magnetic shield (figure 6-38). 21. Disconnect wiring harness from module.
19. Remove retaining ring and remove pickup coil, 22. Check module with an approved module
magnet, and pole piece (figure 6-39). tester.

7226-200-007
7226-200-009
Figure 6-37 Driving Pin From Shaft
Figure 6-39 Aluminum Non-Magnetic Shield
Removed

7226-200-010

Figure 6-40 Removing Pickup Coil, Magnet, and

Pole Piece
7226-200-008

Figure 6-38 Ignition Coil Attaching Screws

IES 131 8/99 6-23

HEI Distributor Service INDUSTRIAL ENGINE SYSTEMS
23. Install module, wiring harness, and capacitor HEI DISTRIBUTOR INSTALLATION -
assembly. Use silicone lubricant on housing
ENGINE DISTURBED
under module (figure 6-41).
24. Assemble pickup and thin “C” washer. Figures 6-42 through 6-44
25. Assemble shaft, gear parts, and roll pin. 1. Rotate engine (in normal direction of rotation)
26. Spin shaft to ensure that teeth do not touch. until timing mark on torsional damper lines up
with TDC on timing tab and engine is in No. 1
27. Loosen, then re-tighten pickup coil teeth to firing position (figures 6-42 and 6-43).
eliminate contact.
28. Install rotor and cap.

600-262

Figure 6-42 Engine Timing Tab

7226-200-011

Figure 6-41 Removing Module, Capacitor, and

Harness

HEI DISTRIBUTOR INSTALLATION -

ENGINE NOT DISTURBED
1. Install distributor shaft into engine, aligning
marks made at time of removal. Be sure that
shaft engages oil pump.
2. Secure distributor with clamp. 143-015

3. Install distributor cap. Figure 6-43 Engine Timing Marks

IMPORTANT: Set engine timing with timing
light. Refer to Specifications and to the proce- 2. Install distributor into engine so that the rotor is
dures in this Section. aligned with No. 1 spark plug tower on distrib-
utor cap (figure 6-44).
3. Secure distributor with clamp.
4. Install distributor cap.

IMPORTANT: Set engine timing with timing

light. Refer to Specifications and to the proce-
dures in this Section.

6-24 IES 131 8/99

Ignition System HEI Distributor Service

IGNITION TIMING - HEI 4. Refer to specifications and adjust base idle

speed (if necessary).
DISTRIBUTOR
5. Aim timing light at timing tab or timing marks
Figures 6-42 through 6-44 located at the crankshaft balancer (figures 6-
The following procedure is used to check and 42 or 6-43).
adjust initial spark timing for the HEI distributor: 6. Loosen the distributor hold-down clamp and
1. Connect the timing light to the No. 1 spark plug rotate the distributor body until the timing mark
(figure 6-44). Connect the power-supply leads on the balancer, or pulley, lines up with the
of the light to 12V battery. mark on the timing tab. Tighten clamp and
recheck timing.
2. Start warm engine and run at idle rpm.
7. Stop the engine and remove the timing light.
3. Disconnect and plug hose from vacuum
advance unit (if equipped). 8. Reconnect vacuum hose (if equipped).

131-088

Figure 6-44 Firing Order

IES 131 8/99 6-25

HEI Distributor Service INDUSTRIAL ENGINE SYSTEMS

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6-26 IES 131 8/99

Table of Contents INDUSTRIAL ENGINE SYSTEMS

TABLE OF CONTENTS
Diaphragm Operated Air-Gas Valve Carburetion ..................................................................................7-1
General Information .................................................................................................................................7-1

Troubleshooting .......................................................................................................................................7-5
All Carburetors .........................................................................................................................................7-5
Natural Gas ..............................................................................................................................................7-5
IMPCO Pressure Reduction Valve...........................................................................................................7-5
LP Gas .....................................................................................................................................................7-5
Balance Lines ..........................................................................................................................................7-5
Natural Gas Carburetion ..........................................................................................................................7-6

7-i IES 131 8/99

Fuel System General Information

DIAPHRAGM OPERATED AIR-GAS

VALVE CARBURETION
GENERAL INFORMATION IMPCO carburetors provide two limited-range
mixture adjustments:
Figures 7-1 through 7-4
1. Idle Air Bypass Adjustment (I). The total
All models of IMPCO air valve carburetors used volume of air and fuel passing the closed throt-
on Crusader Industrial Engines utilize diaphragms tle at idle is constant. The idle adjustment
of fiberglass and synthetic rubber or silicone mater- bypasses a portion of incoming air around the
ial. Cranking the engine lowers pressure in shaded air valve opening. As the idle adjustment is
area as piston decends. Through passages (P) in opened, the air valve partially closes, thereby
the air valve, lowered pressure is communicated to closing the gas metering valve and leaning the
upper side of diaphragm (D). As a result, atmos- idle air-fuel mixture.
pheric pressure pushing upward on the diaphragm
2. Power Mixture Adjustment (A). Controls
lifts it against the downward pressure of the meter-
mixtures when gas metering valve is with-
ing spring (S).
drawn from the jet. This adjustment is effec-
Approximately 0.2 PSI (6.1 in. WC) of pressure is tive only when the engine approaches full-load
required to lift the air valve off its seat. Approxi- condition and can be set only with the engine
mately 0.5 PSI (13.8 in. WC) lifts the valve to the top loaded, at or close to its rated RPM limit.
of its travel in full open position. Mixtures between idle and full-load conditions are
Lowered pressure communicated to the top of the controlled by the gas metering valve shape. The
diaphragm varies with engine speed and position of gas metering valve is shaped to produce lean
throttle valve opening (T). The air valve assembly mixtures at light loads and increasingly rich
measures the air flow into the engine by moving mixtures at heavier loads and higher engine
precisely in response to the demands of the engine speeds.
and throttle valve position. The shape of the gas valve is designed for opti-
The controlled pressure drop of 0.2 - 0.5 PSI (6.1 mum mixtures for the mid-size engine between the
- 13.8 in. WC) set up by the metering spring largest and smallest cubic inch displacement upon
provides the signal or force necessary to draw fuel which the carburetor will be installed.
into the air stream within the carburetor. The gas
metering valve V is attached to the air valve assem-
bly and is shaped to admit the correct amount of
fuel from the gas jet to mix with incoming air at any
opening of the air valve.

IES 8/99 7-1

General Information INDUSTRIAL ENGINE SYSTEMS

131-143

Figure 7-1 Adjustment and Flow Diaphragm

7-2 IES 8/99

Fuel System General Information

131-144

Figure 7-2 Cross-section of Impco CA425 Mixer

131-145

Figure 7-3 Mixer Bottom View

IES 8/99 7-3

General Information INDUSTRIAL ENGINES SYSTEMS

131-146

Figure 7-4 Natural Gas Stationary Air-Gas Valve Operation

7-4 IES 8/99

Fuel System Troubleshooting

TROUBLESHOOTING
ALL CARBURETORS LP GAS
1. Check schematic piping layout for pipe and 1. LP gas inlet pressure to the carburetor should
line regulator orifice size. be 1.5 in. (negative) WC as set by the IMPCO
2. Examine original carburetor for direction of EB Vaporizer/ Regulator (blue spring).
throttle fly opening and lever position.
WARNING
NATURAL GAS
1. Set natural gas pressure at idle to 3 ounces (5 Installing IMPCO carburetors with other makes of
in. WC) for 1,000 BTU gas. vaporizer/regulators is not recommended; the
carburetor will operate rich in the middle range
2. Full load gas pressure may drop as low as 2 in. and cause low mileage. All competitive vaporiz-
WC at the carburetor gas inlet. Exact pressure ers are set by the manufacturer to operate from
at full load is immaterial as long as power (negative) WC. Use brass or plastic fittings only
mixture adjustment is still effective. in water connections on Model E, J and L
3. Adjust carburetor to optimum mixture as Converters.
recommended by the manufacturer at full load.
The power adjustment is not effective at a fast
idle or light load.
BALANCE LINES
1. Due to the insensitivity of the air-valve carbu-
IMPCO PRESSURE REDUCTION retor to minor inlet air restrictions, most instal-
VALVE lations do not require a balance line.
1. Natural gas pressure at carburetor should not 2. Balance lines may be used on all IMPCO
exceed 3 ounces (5 in. WC) for 1,000 BTU carburetors. Series 100 carburetors have a
gas. When pressure cannot be reduced at the compensator built in to correct for pulsations in
line regulator to 3 ounces, or more pressure the balance line air due to four cylinder
must be used to overcome line loss of pres- engines. Series 100 balance lines should be
sure due to small pipe or long line, use an 5/16” I.D.
IMPCO secondary pressure reduction valve at 3. Series 200 carburetors use a 7/16” I.D.
the carburetor. The line (primary) regulator balance line with no compensator.
may then be set as high as 14 ounces (25 in.
WC).
2. An IMPCO pressure reduction valve at each
carburetor is desirable when several engines
are using gas from a single line regulator.
3. For power package units assembled and
shipped to customers, the IMPCO pressure
reduction valve removes the possibility of
excess pressure to the carburetor.

IES 8/99 7-5

Troubleshooting INDUSTRIAL ENGINE SYSTEMS

NATURAL GAS CARBURETION At full engine load of 2 - 7 in. Hg intake mani-

fold vacuum, the gas pressure ideally should
1. Gas carburetion, because of its simplicity, is not drop more than 2 in. WC, although this is
unlikely to give any problems when properly of no matter as long as the power adjustment
installed with an adequate supply of gas. on the carburetor is effective in controlling full
Since the carburetor has the least complicated load mixtures.
function to perform, and has the fewest moving
If the power adjustment is not effective, it indi-
parts, it would be well to exhaust every other
cates:
avenue of possible mechanical or electrical
failure before tampering with gas pressure or A. The engine is lightly loaded and gas meter-
carburetor adjustments, particularly if the ing valve is not withdrawn from the gasjet.
system has been functioning normally in the Mixture may be richened by increasing gas
past. pressure.
2. If carburetion is definitely at fault, the first B. Heat content of the fuel is less than 1000
corrective step is to measure gas inlet pres- BTU per cubic foot. Increase gas pressure.
sures at idle and full load with a water It may be raised to 12 - 16 in. WC if neces-
manometer. Do not attempt to measure gas sary.
pressure with a mercury manometer. If this C. If mixture is still too lean, try DG (digester
pressure is determined to be correct for the gas) air-gas valve assembly in the carbure-
BTU content of the fuel and the light load tor with normal gas pressure of 5 - 7 in. WC.
mixtures it is desired to maintain, proceed to
D. If mixture is still too lean, the BTU content
the next step described under paragraph 3.
must be as low as 600 to 700 BTU per cubic
A water manometer may be easily constructed foot. Substitute a complete DG (digester
if no manufactured model is available. Using gas) mixer in place of the standard model.
transparent plastic tubing from a hardware This DG model is effective down to 600 BTU
store, a “U” can be formed on a board with a per cubic foot.
ruler taped next to the “U” approximately
Pressures recommended for various condi-
halfway between the top and bottom. Fill the
tions of load and fuel heat content are
“U” tube halfway with water and measure the
covered in paragraph 8.
number of inches between the two levels of
water when pressure is applied to one end of 3. If conditions still indicate carburetor malfunc-
the tube. tion, remove the air valve cover (or covers)
and lift out the spring and air gas valve
Failing this, a piece of automotive vacuum
complete with diaphragm.
hose may be marked off into inches at one
end. This may be weighted by forcing a small A. Inspect diaphragm for possible holes, or
steel nut or one or two washers over the charring from excessive heat or backfiring.
scaled end. Drop the weighted end in a The diaphragm should be reasonably flexi-
container of water. With the other end fastened ble. Diaphragm life under normal conditions
to the pressure source, adjust the pressure to should be as much as five years without diff
the point where bubbles start to flow at the iculty. Heat from proximity to exhaust mani-
depth in inches at which the desired pressure folds, or from turbocharged air which is not
is reached. Quite an exact check can be made properly cooled due to insufficient water
by raising or lowering the hose slightly to see circulation (or hot water) through the inter-
the exact depth at which bubbles start to flow. cooler, can shorten diaphragm life consider-
ably IMPCO has a silicone rubber on fiber-
With the engine running at idle, gas pressure
glass diaphragm for extreme heat condi-
should be 5 - 7 in. WC depending on light load
tions available on special order.
air-fuel mixtures you wish to maintain. Using
1050 BTU natural gas, 7 in. WC will produce a
straight power mixture, while 5 in. WC will give
economy mixtures at light load.

7-6 IES 8/99

Fuel System Troubleshooting

B. If diaphragms prove sound, check the inside withdrawn from the jet, the major restriction to
diameter of the air valve cup and the fins on gas flow becomes the power mixture adjust-
the outside of the gas jet which guide the air ment, which is most effective at full load, and
valve. Under ultrahigh frequency vibrations decreasingly effective down to approximately
sometimes encountered, it is possible to one-half load, where it no longer has much
find grooves worn in the cup by the fins, effect.
which may lead to poor metering as the 6. This dual control of mixtures at different load
valve tries to pass up and down over the settings makes it possible to maintain a
step. straight best-power mixture from idle to full
C. Also inspect the inside diameter of the gas power with increased gas pressure up to
jet, and the outside diameter of the small certain limits, or a lean light-load mixture may
tapered gas valve for possible wear from the be obtained with lower gas pressure and read-
same cause. justment of the power mixture adjustment to
D. If everything to this point appears okay, proper full load mixtures.
wash all the parts thoroughly in kerosene or 7. Note the graph showing air-fuel mixtures
the equivalent. obtained at light and full load with various inlet
E. Reassemble cleaned or replaced parts in pressures to the carburetor. Graphs for differ-
the bowl, centering the spring on the air ent engine configurations will vary as to the
valve, and replace and fasten the cover. percentage of load where the curve moves
From the air-fuel outlet of the mixer to the from the mixture controlled by gas pressure to
throttle body, reach in with fingers or non- the mixture controlled by the power mixture
sharp rod and lift valve several times to adjustment. This is so because of the rela-
assure free travel with the spring closing the tionship of carburetor size to engine displace-
valve. Check the gas valve for leaks in ment and speed. A large engine with a
closed position by applying a vacuum to the comparatively small carburetor will withdraw
gas inlet. It should be sealed. the gas metering valve from the jet more quick-
ly and at a lesser percentage of load than a
4. To understand the flexible control of the large carburetor on a small engine. Different
mixtures under various conditions of load, the IMPCO carburetors vary slightly as to ideal
air-gas valve assembly is the only moving part gas inlet pressure for best economy Five inch-
in the mixers. The air-flow measuring valve es of water column gas pressure is a compro-
rises precisely in relation to the volume of air mise which suits most conditions with 1050
consumed by the engine, which is in turn BTU fuel.
controlled by engine speed and throttle posi-
tion. 8. For fuel with less heat (BTUs) per cubic foot,
an increase in gas inlet pressure to 10 - 12 in.
With the air-gas valve assembly lifted about WC will compensate for fuel down to 900-950
one-third of the available travel, the greatest BTU heat value.
restriction to gas flow is the shaped gas meter-
ing valve, the bulk of which is not yet with- 9. No compensation in mixtures is necessary
drawn from the gas jet. In this position, the because of altitude changes. Air and gas
power adjustment valve has little or no control expand essentially the same amount at high
over mixtures, since even in its fully closed altitude, whereas gasoline has a constant
position, its restriction to gas flow is less than density so that mixtures richen at high altitude.
that of the metering valve. Mixtures may be Power declines 3% for each 1000 feet of alti-
leaned or richened with the valve in this or less tude even with correct air-fuel mixtures, so that
open positions by increasing or decreasing loss with gasoline is even greater. Consump-
gas pressure to the carburetor. tion of liquid fuel per horsepower hour increas-
5. Full power mixtures are controlled by the es at higher altitude unless the carburetor or
power mixture adjustment. This adjustment injection system is adjusted to compensate for
must be made with the engine under full or altitude.
working load. With the gas metering valve

IES 8/99 7-7

Troubleshooting INDUSTRIAL ENGINE SYSTEMS
10. A turbocharged engine likewise causes no A slight adjustment of the power mixture
problem with air-fuel mixture ratios. By using towards lean will compensate for the air
a balance pressure connection from the air temperature rise.
inlet at the carburetor to the atmospheric vent 11. Hot intake air to a naturally-aspirated engine
of the gas regulator, both air and gas densities cuts power production materially, as well as
increase equally. Volume of air-gas flow is the increasing the possibility of detonation and
same as in a naturally-aspirated engine, pre-ignition, which can injure or destroy an
however the weight of air and fuel flowing is engine in short order. Aside from power loss
increased by pressurizing each. In order to from detonation, there is a loss of 1% of power
check the fuel to air pressure differential, which for each 10° of air temperature rise. Roughly
should still be approximately 5 in. WC at idle seven pounds of air is required to produce one
for 1050 BTU gas, it is necessary to connect horsepower for one hour. Since heating air
the water manometer to the air pressure enter- lightens it (as in a hot air balloon) a greater
ing the carburetor, and to the gas pressure volume of hot air is required to weigh seven
entering the carburetor, This will measure the pounds. An engine at full load will only breathe
difference in pressures only, not the total pres- a fixed volume of air, so that the number of
sure of either. This difference should be the available pounds of air are reduced by using
same as that of a naturally-aspirated system. hot air to the carburetor.
One minor difference in mixtures occurs due to 12. Heated air to the carburetor is especially criti-
compression heating of the air by the turbo- cal in turbocharged installation using propane
compressor. This air temperature is almost fuel full or part-time. Water temperature is
always controlled by the use of an inter-cooler; required to be 60°F through the inter-cooler for
however the temperature still rises a bit above a 10:1 compression ratio with turbocharger, in
ambient temperature. This causes a slight order to avoid detonation. This cold water is
richening of the air-fuel ratio, since the gas seldom available.
remains at relatively constant temperature as
the air temperature is raised.

131-147

Figure 7-5 Fuel Thermal Comparison Chart

7-8 IES 8/99

Table of Contents INDUSTRIAL ENGINE SYSTMES

TABLE OF CONTENTS
Pierce / Hoof Governor System...............................................................................................................8-1
General Description .................................................................................................................................8-1
Governor Operation .................................................................................................................................8-1
Velocity Governor Installation ..................................................................................................................8-2
Adjustment Procedures............................................................................................................................8-2
Troubleshooting........................................................................................................................................8-4

Aisan Governor System ...........................................................................................................................8-5

General Description .................................................................................................................................8-5
Governor Operation .................................................................................................................................8-6
Adjustment Procedures............................................................................................................................8-6

8-i IES 131 8/99

Governor System Pierce / Hoof Governor

PIERCE / HOOF GOVERNOR SYSTEM

GENERAL DESCRIPTION cantilever spring tension. When a load is applied,
the engine speed drops and the velocity of the fuel
The velocity governor is a maximum speed type mixture flowing through the governor decreases.
and operates by metering the gasoline/air mixture Pressure against the governor valve drops, and the
flow from the carburetor. It is designed to limit the spring force causes the valve to open wider, thus
engine speed to a predetermined maximum number admitting more fuel to the engine. The engine
of revolutions per minute. accelerates to keep the load from stalling the
The governor is installed between the carburetor engine, and finds a speed at which the force
and intake manifold. It contains a governor valve between the governor valve and the cantilever
mounted on a shaft which is similar in appearance spring are again in balance.
to a carburetor butterfly valve. However, unlike a
butterfly valve, the governor shaft is mounted off- Partially Closed Throttle Operation
center in the governor bore.
In a fully open throttle condition illustrated at (a),
there is a slight vacuum below the partially closed
GOVERNOR OPERATION governor valve (1); this tends to close the valve but
Figure 8-1 and 8-2 is prevented from doing so by the normal compen-
sating action of the cantilever spring. If the carbu-
When the engine is running, the gasoline/air retor butterfly valve is partly closed, as illustrated at
mixture passing through the governor bore (b), a vacuum above the governor is created which
impinges on the valve (1) and attempts to close it, is greater than the vacuum below it; the valve would
the closing force increasing with the engine speed. then tend to open wider, thus allowing the engine
The closing action of the valve is opposed by a speed to exceed its preset governed speed. Under
cantilever spring (2) which acts on the lever (3) these conditions, the diaphragm (2) is forced inward
fixed to the end of the valve shaft. The tension of as shown, by the increased vacuum and starts to
the cantilever spring is adjusted by means of the close the valve again by means of the pivoted lever
main adjustment screw (4). (3) acting on the arm (4) which is attached to the
governor valve.

131-165

Figure 8-1 Velocity Governor Operation 131-166

Figure 8-2 Partially Closed Throttle Control *

When the air velocity force acting on the valve
equals the opposing spring force, the valve * A - Intake Manifold B - Governor
assumes a position which controls the amount of
fuel reaching the engine. The maximum engine C - Carburetor D - Carburetor Butterfly
speed is thus governed by the pre-setting of the

IES 8/99 8-1

Pierce / Hoof Governor INDUSTRIAL ENGINE SYSTEMS

VELOCITY GOVERNOR ADJUSTMENT PROCEDURES

INSTALLATION Figures 8-4 through 8-6
Figure 8-3 Main Speed Adjustment
To install the Velocity Governor, disconnect the 1. Turn the MAIN SPEED ADJUSTING SCREW
gas line, choke control wire, and carburetor control clockwise for higher speeds, and counterclock-
rod. If the engine is equipped with vacuum spark wise for lower speeds. Always end the adjust-
advance control, disconnect the vacuum line at the ment with a clockwise turn to keep the lost-
carburetor. motion in the governor linkage in a positive
Remove the carburetor. Remove the carburetor direction. If the speed is too high, turn the
mounting studs and replace them with longer studs adjustment counterclockwise below the
to accommodate the governor and carburetor required speed, and then turn the adjustment
length. clockwise up to the required speed.
2. When the desired speed is reached, seal the
Install the governor with the speed adjusting
MAIN ADJUSTING SCREW by forcing Silicon
screw in the most convenient location. In general,
Sealer into the cavity around the screw. Sealer
the carburetor throttle valve and governor valve
must enter the slot of the screw to lock the
should close in the same direction, for best perfor-
screw from turning during engine operation.
mance. The arrow on the side of the governor indi-
cates the governor flange which should fit next to Sensitivity Adjustment
the carburetor flange.
The SENSITIVITY ADJUSTMENT is factory set
and sealed to cover a range of engine speeds. Only
Installation With Downdraft Carburetor
in rare instances should the sensitivity adjustment
Install the governor between the carburetor and be changed. To readjust the sensitivity adjustment,
the intake manifold, using gaskets supplied. Make proceed as follows:
sure arrow cast on side of governor points to the
1. Remove the Welch Plug covering the SENSI-
carburetor. If carburetor and governor throttle
TIVITY ADJUSTING SCREW by carefully
valves contact each other, use a spacer or addi-
drilling a 1/8 in. diameter hole through the
tional gaskets between the carburetor and governor
center of the plug, and prying the plug out
to prevent valve clash.
using the back end of the drill.
2. If the engine is hunting or is unstable, turn the
SENSITIVITY SCREW 1/4 turn clockwise, and
readjust the MAIN ADJUSTING SCREW to
obtain the desired speed. Always end each
adjustment with a clockwise turn. Test the
engine performance, and repeat this proce-
dure as required.
3. If the engine speed drops excessively when
loaded, turn the SENSITIVITY SCREW 1/2
turn counterclockwise, then turn this screw 1/4
turn clockwise. Readjust the MAIN ADJUST-
ING SCREW to obtain the desired speed.
Always end each adjustment with a clockwise
turn. Test the engine performance, and repeat
this procedure as required.
131-167
4. When all adjustments are satisfactorily
completed, seal the adjusting screws by forc-
Figure 8-3 Downdraft Carburetor Installation ing Silicon Sealer into the cavity around the
screw. Sealer must enter the slot of the screw
to lock the screw from turning during engine
operation.
8-2 IES 8/99
Governor System Pierce / Hoof Governor

131-148

Figure 8-4 Pierce / Hoof Governor Part No. S203P / S203PA (Crusader Part No. 7173170)

131-149

Figure 8-5 Pierce / Hoof Governor: Part No. S2080A (Crusader Part No. 7160520)
Part No. S2081 (Crusader Part No. 7173180)

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Pierce / Hoof Governor INDUSTRIAL ENGINE SYSTEMS

131-150

Figure 8-6 Pierce / Hoof Governor Part No. S6008 (Crusader Part No. 7172680)

TROUBLESHOOTING Engine Lacks Power And Performance

Engine Speed Wanders At High Idle The carburetor power valve must be vented to the
top groove on the governor flange. Use slotted
Caused by a carburetor float level too high, float gaskets provided with the governor. The carburetor
not shutting off, fuel dripping into the venturi, carbu- power valve channel leading to the bore must be
retor power valve stuck in the rich position. blocked from the bore (use lead shot or epoxy).
Also check for the correct spark advance vacuum
Sudden Change In Governor Performance connections.
Caused by an increase in exhaust back-pressure,
a leaky intake manifold gasket, a clogged air filter, Governor Runs Broad
excessive crankcase blow-by gas, or a defective A velocity governor adjusted for gasoline will run
PCV valve. 400 to 600 R.P.M. broader if the fuel is changed to
L.P.G. Also, a governor will run 200 R.P.M. broader
Sudden Change In Engine Speed for each 1000 feet altitude it is operated at above
Caused by a broken governor cantilever spring. sea level. The secondary adjustment can be read-
Spring may be rusty or fatigued by being over- justed to sharpen the regulation. Also check to see
stressed. that the governor throttle plate and carburetor throt-
tle plate both close in the same direction. If they do
not, rotate the governor 180° on its studs.
Gradual Drop In Engine Speed
Caused by carburetor ice. If the air temperature is Engine Hunts continually
20° to 48° and the humidity Is high (70% or higher),
ice can form on the governor throttle plate, causing The crankcase PCV valve must be vented above
speed to drop off gradually until the ice melts off. or through a tube on the governor. If vented below
the governor into the intake manifold, hunting can
Then the speed will return to normal. result.

8-4 IES 8/99

Governor System Aisan Governor

AISAN GOVERNOR SYSTEM

GENERAL DESCRIPTION
Figures 8-7 through 8-9
Governors are regulating devices which allow
engine speed to remain constant in both loaded and
unloaded operating conditions. There are several
different types of governor designs such as
mechanical, hydraulic, electric and velocity used to
control engine speed. Governors normally control
engine speed by limiting the amount of air and fuel
entering the engine. On velocity governors, the air
flowing through the carburetor strikes the governor 7226-400-015

valve. This governor valve would close off Figure 8-7 Governor Installation
completely if not for the opposing action of the cam
and governor spring. When the spring tension and
air flow are balanced, governing action takes place
and engine speed remains fixed at that point.
When additional load is applied, the engine speed
drops and the velocity of the fuel mixture is
reduced. With lower air velocity through the gover-
nor the pressure against the governor valve is
reduced and the spring opens the governor valve to
supply more fuel to the engine to meet the
7226-400-016
increased load demand. This allows a constant
engine speed to be maintained with or without a Figure 8-8 Governor Mechanism
load on the engine.
Stabilizer Piston
Components While the governor valve is limited to a specific
In order for the velocity governor to control engine opening angle, engine speed will oscillate due to
speed within a specified range, a control mecha- pulsations in the intake system of the engine.
nism is required to limit the amount of fuel entering These pulses, while a normal condition in engine
the engine. On the Aisan Governor this function is operation, will cause the engine speed to oscillate
performed by the governor valve. The governor (surging). To minimize this condition, a stabilizer
valve is mounted on an off-set shaft, which when piston is incorporated into the governor design
encountering high air flow through the venturi, will (figure 8-4). The stabilizer piston is connected to
attempt to close, thus limiting the amount of air and the governor valve by means of a rod. A slot in the
fuel entering the engine (figure 8-7). The closing hole for the rod works as a vacuum passage for the
force is opposed by a cam and spring mechanism piston. When the governor valve is subjected to
(figure 8-8). When the opposing forces are pulsations, the stabilizer piston, which is held in
balanced, the governor valve stops at a fixed posi- place by engine vacuum prevents the movement of
tion and maintains engine speed at a constant the governor valve. The stabilizer piston works in
setting. The opening angle of the governor valve is conjunction with the cam and spring assembly to
adjusted by means of an adjusting screw. balance the pressure on the governor valve while
maintaining a constant engine speed. In order to
perform this action smoothly, the back face of the
stabilizer is exposed to atmospheric pressure. This
opening should be connected to the engine air
cleaner or external filter to prevent dirt ingestion.

IES 8/99 8-5

Aisan Governor INDUSTRIAL ENGINE SYSTEMS
High Engine Load
When the engine is operating at high engine loads
the venturi vacuum will be lowered closer to atmos-
pheric pressure. This drop in vacuum causes the
stabilizer piston to move outward due to the pres-
sure being exerted on the governor valve by the
governor spring (figure 8-12). This condition allows
7226-400-017
the governor valve to open further allowing addi-
Figure 8-9 Stabilizer Piston tional fuel and air into the engine to maintain a
constant engine speed.
GOVERNOR OPERATION
Figures 8-10 through 8-12
Engine Stopped
When the engine is not operating, the governor
valve is held in the open position by the pressure
exerted on the cam by the governor spring (figure 8-
10).

7226-400-020

Figure 8-12 Under High Engine Load

ADJUSTMENT PROCEDURES
Figure 8-13
When the engine is subjected to a load, the
engine speed must be 100 RPM or less than the
7226-400-018 engine speed obtained under a no load condition.
There must not be any surging present.
Figure 8-10 During Engine Stopped
Engine Speed
Low Engine Load
1. The engine must be warmed up to the normal
When the engine is operated under low load operating temperature.
conditions, the venturi vacuum will draw the stabi-
2. Adjust the maximum engine speed to specifi-
lizer piston inward (figure 8-11). This pressure will
cation by the following procedure.
overcome the spring force and the governor valve
will close. When RPM is higher then specification:
Turn the ADJUSTING SCREW counterclockwise
to lower the engine RPMs to proper setting.

When RPM is lower then specification:

Turn the ADJUSTING SCREW BUSHING clock-
wise to increase the engine RPMs. If engine speed
is now above specification then turn the adjusting
screw counterclockwise to lower the engine RPM to
proper setting.
7226-400-019 3. Install lock wire through holes in adjusting
Figure 8-11 Under Low Engine Load screw and bushing to prevent screw from
moving due to engine vibration.

8-6 IES 8/99

Governor System Aisan Governor

7226-400-014

Figure 8-13 Aisan Governor Assembly #7172730

Surging No Surging But RPM Variance Greater

If surging is observed, perform the following Than 100 RPM
steps: When no surging is observed but the engine RPM
1. Turn the ADJUSTING SCREW clockwise difference is greater than 100 RPM between no
approximately 90 degrees. (Increase of maxi- load and full load, perform the following steps:
mum engine speed without load with this 1. Turn the ADJUSTING SCREW BUSHING
adjustment should be less than 100 RPM. clockwise 90 degrees.
2. Turn the ADJUSTING SCREW BUSHING 2. Turn the ADJUSTING SCREW counterclock-
counterclockwise until the maximum engine wise to adjust the maximum engine speed
speed without load comes into specification. without load to specification.
3. Check if surging is still present when engine is 3. Check if surging is observed when engine is
subjected to engine load. operated under load.

If surging is still present, repeat steps 1 thru 3 If necessary repeat steps 1 thru 3 until adjusted
until adjusted properly. properly.
4. Install lock wire through holes in adjusting 4. Install lock wire through holes in adjusting
screw and bushing to prevent screw from screw and bushing to prevent screw from
moving due to engine vibration. moving due to engine vibration

IES 8/99 8-7

Aisan Governor INDUSTRIAL ENGINE SYSTEMS

THIS PAGE WAS INTENTIONALLY LEFT BLANK

8-8 IES 8/99

Table of Contents INDUSTRIAL ENGINE SYSTEMS

TABLE OF CONTENTS
General Information .................................................................................................................................9-1
Cooling Systems ......................................................................................................................................9-1
Radiator Systems.....................................................................................................................................9-3
Heat Exchanger Systems ........................................................................................................................9-4
Coolant Mixture ........................................................................................................................................9-5
Thermostat ...............................................................................................................................................9-6

Diagnosis ..................................................................................................................................................9-7
System Checks ........................................................................................................................................9-7
V-Belt Pulley System .............................................................................................................................9-10
Engine Vibration .....................................................................................................................................9-11
Serpentine Belt System .........................................................................................................................9-12
Pulley Inspection (All) ............................................................................................................................9-14

Service Procedures ................................................................................................................................9-15

Draining and Filling the Cooling System................................................................................................9-15
Flushing the Cooling System .................................................................................................................9-15
Coolant Recovery / Surge Tank Replacement.......................................................................................9-15
Engine Coolant Temperature Sensor Replacement ..............................................................................9-16
Thermostat Replacement.......................................................................................................................9-16
Coolant Pump Replacement ..................................................................................................................9-17
Drive Belt Tensioner Inspection .............................................................................................................9-18
Drive Belt Tensioner Replacement ........................................................................................................9-18
Idler Pulley and Bracket Replacement...................................................................................................9-18
Drive Belt Service (All) ...........................................................................................................................9-18
V-Belt Replacement ...............................................................................................................................9-18
Serpentine Belt Replacement ................................................................................................................9-19
Belt Tension Adjustment (All) .................................................................................................................9-20
Radiator Service ....................................................................................................................................9-20
Heat Exchanger Service ........................................................................................................................9-21
Coolant Hose Replacement ...................................................................................................................9-21
Fan Replacement...................................................................................................................................9-22

9-i IES 131 8/99

Cooling System General Information

GENERAL INFORMATION
COOLING SYSTEMS while the heat exchanger system (figure 9-2) uses
an external water supply for cooling. Both systems
Figures 9-1 and 9-2 use a thermostat to control coolant circulation.
The cooling system maintains engine tempera- The cooling system is sealed by a pressure type
ture at an efficient level during all engine operating cap that causes the system to operate at higher
conditions. When the engine is cold, the cooling than atmospheric pressure. The high pressure
system cools slowly or not at all, to allow the engine operation raises the boiling point of the coolant,
to warm up quickly. thereby increasing the cooling efficiency. The pres-
Crusader Industrial Power Products utilize two sure cap raises the boiling point of the coolant up to
different pressure type engine cooling systems. 125°C (257°F) at sea level depending upon the
The radiator system (figure 9-1) uses forced air pressure rating of the cap.

131-076

Figure 9-1 Typical Radiator System

IES 8/99 9-1

General Information INDUSTRIAL ENGINE SYSTEMS

131-077

Figure 9-2 Heat Exchanger / Expansion Tank Cooling System

9-2 IES 8/99

Cooling System General Information

RADIATOR SYSTEMS Coolant Recovery Tank

Figure 9-3 A “see-through” plastic reservoir is connected to
the radiator by a hose. As the engine is run, the
The radiator is a device in the cooling system that coolant is heated and expands. The portion of the
removes heat from the coolant passing through it, fluid displaced by this expansion flows from the
allowing the coolant to remove heat from the radiator into the recovery bottle. When the engine
engine. is stopped and the coolant cools and contracts,
Hot engine coolant flows from the engine into the vacuum draws the displaced coolant back into the
top of the radiator through the inlet hose. The radiator. Thus, the radiator is kept filled with coolant
coolant is passed through tubes inside the radiator. to the desired level at all times, resulting in
Fan forced ambient air passes across the radiator increased cooling efficiency.
fins and tubes which dissipates heat from the Keep the coolant level at the “FULL” mark when
coolant. Coolant leaves the radiator at the bottom hot. There is about one liter (one quart) difference
and returns to the engine cooling system. between the “ADD” and “FULL” marks.

131-079

Figure 9-3 Typical Radiator System

IES 8/99 9-3

General Information INDUSTRIAL ENGINE SYSTEMS

HEAT EXCHANGER SYSTEMS Expansion Tank

Figure 9-4 An expansion tank is connected to the heat
exchanger by a hose. As the engine is run, the
The heat exchanger is a device in the cooling coolant is heated and expands. The portion of the
system that removes heat from the coolant passing fluid displaced by this expansion flows from the
through it, allowing the coolant to remove heat from heat exchanger into the expansion tank. When the
the engine. engine is stopped and the coolant cools and
Hot engine coolant flows from passages in the contracts, vacuum draws the displaced coolant
exhaust manifolds into the heat exchanger through back into the heat exchanger. Thus, the heat
the inlet fitting. Cool water circulates along side the exchanger is kept filled with coolant to the desired
tubes carrying the hot engine coolant. The cool level at all times, resulting in increased cooling effi-
water dissipates heat from the coolant as it passes ciency.
through the heat exchanger tubes. Coolant leaves Keep the cold coolant level at about 1 inch below
the heat exchanger through the outlet fitting and the top of the expansion tank. Always use the
returns to the engine cooling system. recommended coolant mixture.

7226-200-022

Figure 9-4 Typical Heat Exchanger Operation

9-4 IES 8/99

Cooling System General Information

COOLANT MIXTURE Water and ethylene glycol base antifreeze coolant

is recommended for year-round use. Coolant solu-
Figure 9-5 tions used must:
Provide for adequate heat transfer.
CAUTION
Provide corrosion-resistant protection within the
cooling system.
Under some conditions, the ethylene glycol in
engine coolant is combustible. To avoid being Prevent formation of scale or sludge deposits in
burned when adding coolant, do not spill the the cooling system.
coolant on the exhaust system or engine parts
Be compatible with cooling system hose and seal
that may be hot.
materials.
Provide adequate freeze protection during cold
weather operation.
Coolant concentration mixtures below 39% by
volume do not provide enough corrosion protection,
and mixtures greater than 67% by volume affect
freeze protection and heat transfer capability (figure
9-5). Pure antifreeze will freeze at -22°C (-8° F).
The coolant solution should contain a year-round
ethylene glycol base coolant which meets GM
Specification 6038-M. The coolant solution is
made to withstand two years of normal operation if
the correct coolant is used when adding, draining,
or filling the cooling system.
It has an inhibitor that provides corrosion protec-
tion, pH control, and water softening. No additional
inhibitors are required unless specified by the
engine manufacturer. A 50/50 mixture of ethylene
glycol and soft or distilled water will provide the
following:
Give freezing protection down to -37°C (-34°F)
Give boiling protection up to 129°C (265°F)
Protect against rust and corrosion
Help maintain proper engine temperature
To test the condition of ethylene glycol based
coolant, use a commercially available tester specif-
ically designed to test ethylene glycol coolant. If
condition of coolant tests poorly, or if coolant has
an improper appearance, drain and refill the cool-
ing system.

131-080

Figure 9-5 Coolant Concentration

IES 8/99 9-5

General Information INDUSTRIAL ENGINE SYSTEMS

THERMOSTAT
Figure 9-6
A pellet-type thermostat in the coolant outlet
passage controls the flow of engine coolant to
provide fast engine warm-up and regulate coolant
temperatures. A wax pellet element in the thermo-
stat expands when heated and contracts when
cooled. The pellet is connected through a piston to
a valve. When the pellet is heated, pressure is
exerted against a rubber diaphragm to force the
valve open. As the pellet cools, the contraction
allows a spring to close the valve. In this way, the
valve remains closed while the coolant is cold,
preventing circulation of coolant through the radia-
tor. At this point, coolant circulates throughout the
engine to warm it quickly and evenly.
As the engine warms, the pellet expands and the
thermostat valve opens, permitting coolant to flow
through the radiator where heat passes through the
radiator walls. This opening and closing of the ther- 600-279
mostat permits enough coolant to enter the radia-
tor to keep the engine within operating temperature Figure 9-6 Thermostat
limits.

9-6 IES 8/99

Cooling System Diagnosis

DIAGNOSIS
SYSTEM CHECKS Coolant Pump
Figures 9-7 through 9-11 Check coolant pump operation by running the
engine while squeezing the upper radiator hose.
Refer to the cooling system diagnosis chart When the engine warms, a pressure surge should
(figure 9-7) for detailed cooling system diagnostic be felt. Check for a plugged vent hole in the pump.
procedures.

600-182

Figure 9-8 Coolant Pump

V-Belt Systems
Inspect the condition of the drive belts. Inspect
for worn, cracked, split, or frayed areas. Replace
any worn belts. Refer to “Drive Belt Replacement.”
Also inspect the belt tension and adjust as needed.
Refer to “Belt Tension Adjustment.” A belt that is
improperly adjusted can cause inefficient fan and
coolant pump operation and also cause the engine
to overheat.
Serpentine Belt Systems
Check the drive belt for looseness, damage, or
fabric delamination. If the belt is loose, check the
belt tensioner for proper operation. The belt
tensioner is not adjustable. If it is not working prop-
erly, it must be replaced. If the belt is delaminated
or damaged, replace it.

IMPORTANT: Cracks across the rib material are

a normal part of the belt aging process. Cracks
do not affect belt operation, and do not indicate
a need to replace it.

131-081

Figure 9-7 Cooling System Diagnosis Chart

IES 8/99 9-7

Diagnosis INDUSTRIAL ENGINE SYSTEMS
Check the belt length scale on the tensioner. If it Testing the Radiator Cap
reads outside the “acceptable” range, check for
proper routing as shown on the belt routing label
and in this section. Also check for proper tracking CAUTION
of belt ribs in the pulley grooves, correct pulley
sizes (including idlers), and correct belt length. To avoid being burned, do not remove the radia-
tor cap while the engine is at normal operating
IMPORTANT: Multiple rib belts stretch and wear temperature. The cooling system will relieve
very little. Normal stretch and wear rarely scalding fluid and steam under pressure if the
exceeds 10 mm (3/8 in.) on the belt length scale. cap is removed while the engine and radiator are
still hot.
Exhaust Leaks
Tool Required:
To check for exhaust leaking into the cooling
J 24460-01 Cooling System Tester
system, drain the system until the coolant level
stands just above the top of the cylinder heads, 1. Remove the radiator cap (1).
then disconnect the upper radiator hose and 2. Wet the radiator cap gasket with coolant.
remove the thermostat and belt. Start the engine Wash off any sediment from the sealing
and accelerate several times. At the same time, surface.
note any appreciable coolant rise or the appear-
3. Install the cap (1) to J 24460-01.
ance of bubbles that may indicate that exhaust
gases are leaking into the cooling system. 4. Pump up the pressure to the pressure
stamped on the cap (1) by operating the
NOTICE: A worn head gasket may allow exhaust plunger handle of J 24460-01.
gases to leak into the cooling system. This can 5. Note the rate of decrease in pressure.
damage the cooling system as the gases combine
6. The pressure reading should remain within the
with the water to form acids that are harmful to the
corresponding pressure segment of the scale
radiator and engine.
for about 10 seconds. Replace the cap (1) if it
Radiator does not hold the pressure for 10 seconds.
Test for restrictions in the radiator by warming the
engine up, turning the engine off, and feeling the
radiator. The radiator should be hot along the left
side and warm along the right side, with an even
temperature rise from right to left. Cold spots in the
radiator indicate clogged sections.
Thermostat
Make an operational check of the thermostat by
changing the thermostat on a hook in a 33 percent
glycol solution, -12°C (10°F) below the temperature
indicated on the valve. With the valve submerged
and the coolant agitated, the valve should close.
Pressure Checks
600-271
Several types of cooling system pressure check- Figure 9-9 Testing Pressure Cap
ing devices are available. Follow the manufacturers
instructions for proper use.

9-8 IES 8/99

Cooling System Diagnosis

Testing the Cooling System

Tool Required:
J 24460-01 Cooling System Tester
1. Tighten all hose clamps.
2. Inspect the connections for leaks at the recov-
ery tank, expansion tank, etc.
3. Remove the filler cap.
4. Fill the cooling system to the level of the filler
cap seat.
5. Attach J 24460-01 to the filler neck of the radi-
ator or heat exchanger. Follow the instructions
supplied with J 24460-01.
6. Build up pressure to no more than 138 kPa (20
psi). 131-083

7. The system should hold the pressure for about Figure 9-11 Pressure Testing Heat Exchanger
two minutes. System
• If a measurable amount of pressure drops in
less than two minutes, check for a leak.
Problems Requiring Disassembly of the Cooling
System
1. Incorrect or damaged fan.
2. Radiator filler neck damage.
• Shows if the pressure cap leaks because of
radiator filler neck damage.
3. Worn or damaged coolant pump.
• Impeller vanes eroded or broken.
• Worn or damaged bearing and/or seal.
• Check for shaft or bearing play.
131-082 4. Plugged radiator tubes.
Figure 9-10 Pressure Testing Radiator Cooling • Perform a flow check.
System 5. Internal system leaks.
• Head gasket.
Uncommon Cooling System Problems
• Cracked block.
Problems Not Requiring Disassembly of the Cooling
System • Timing chain cover.
1. Remove large obstructions blocking the radia- • Intake manifold gasket.
tor. Auxiliary oil cooler(s).
6. Plugged coolant passages in the cylinder
2. Engine oil is overfilled. heads.
3. Incorrect radiator for the application. Check • Visual check.
the part number.
4. Loose, damaged, or missing air seals.
5. Missing or damaged lower air baffle.
6. Incorrect ignition timing.

IES 8/99 9-9

Diagnosis INDUSTRIAL ENGINE SYSTEMS

V-BELT PULLEY SYSTEM Slip Burn

Slip burns occur when the belts are too loose or
Belts and pulleys wear evenly with use. Unusual slipping under load. Install a new belt and adjust
signs of wear indicate some correction is needed. properly. Check for a worn pulley.
The correction of any of the listed conditions will
Gouged Edge
help extend belt life.
A gouged edge in a belt can be caused by a
Causes of Belt failure damaged pulley, a misaligned pulley, or the belt
being too loose or too long. Check the pulley and
• Misalignment of the pulleys.
the belt for proper alignment and tension. Make
• Wrong size belt. sure other components are not misaligned and
• Wrong length belt. rubbing against the belt.
• Wrong tension. Worn Sides
• Damaged pulley sheaves or bent pulley shafts. Belts that are worn on the sides are probably too
loose. The pulley may also be misaligned. Install a
• Damaged belt. new belt and adjust properly. Check for a worn or
• Belt damaged during installation. misaligned pulley.
• Oil or grease on belts. Excessive Stretch
Base Cracking A belt that is stretched beyond adjustment is
A belt with excessive cross-checking that extends usually the wrong size or is adjusted too tight.
into the rubber on the base of a belt and shows little Replace the belt and adjust the tension.
or no side wear indicates the belt is damaged. If the Flat Spots
base of the belt shows cross-checking, the belt has Flat spots may result by not relieving the belt
been exposed to weather to the extent that the tension while storing the vehicle or engine. A
fabric is starting to rot. temporary vibration will occur when the engine is
Fabric Tear first started. Flat spots are most noticeable with
A fabric tear can be the result of: variable speed drives. Flat spots may disappear
during normal engine operation. If the flat spots
• Operating a belt on a worn pulley.
remain, replace the belts.
• Belt tension too light causing the belt to ride in
Internal Cord Damage
the pulley groove.
Cords may be broken by prying the belt onto the
• Dirty pulley grooves. pulley or debris on the pulley. Internal cord damage
• Pulley misaligned. will cause the belt to roll out of the pulley groove.
Cover Tear Replace the belt and adjust properly.
Cover tears result when the belts are too loose or
too long and the belt rubs against other compo-
nents. Adjust the belt tension and use the correct
length of belt.

9-10 IES 8/99

Cooling System Diagnosis

ENGINE VIBRATION Belt Deterioration

Fan Blade Assembly Damaged Oil or grease on the belts or pulley or use of belt
Fan blades that are split loose, bent, or have dressings will soften belts and cause deterioration.
loose mounting brackets or shaft assembly, may Clean the belts and pulley grooves with nonflam-
cause the engine to vibrate. Replace the fan blade mable cleaner or solvent, or detergent soap and
assembly. Tighten the mounting bracket or shaft water. Replace the belts as needed.
assembly and check the pulley alignment. Check
Belt Disintegration
the belts and pulleys for damage and adjust the belt
tension. Belt disintegration may be caused by excessive,
engine speed, misaligned pulleys, wrong belt size,
Flat Spots
or wrong tension. Check the pulleys for alignment
Flat spots may result by not relieving the belt
and the belts for correct length and tension. A belt
tension while storing the vehicle or engine. A
may begin to disintegrate because of normal wear
temporary vibration will occur when the engine is
after extended use, extreme temperatures, or not
first started. Flat spots on the belts may disappear
inspecting or adjusting the belt.
during normal engine operation. If the flat spots
remain, replace the belts. Belt Flip-Over
Uneven Belt wear (One Side Only) Belt flip-over usually occurs at high speeds and is
the result of misaligned pulley(s). Check pulley
Loose engine mounts or misaligned pulleys may
alignment. If belt flip-over occurs at low speed,
cause the belt to wear on one side. Check the
check for the correct length belt and proper belt
pulley for rough surfaces, scratches, and a bent
tension.
pulley wall. Align or replace the pulley.
Belt Glazed
A glazed belt is the result of slipping. One of the
following conditions may be the cause:
• Insufficient pressure on the belt sides.
• Oil on belt surfaces.
• Incorrect belt tension.
• Incorrect belt size.
• Misaligned pulley.
• Binding pulley.
• Bent pulley.

IES 8/99 9-11

Diagnosis INDUSTRIAL ENGINE SYSTEMS

SERPENTINE BELT SYSTEM Definitions:

Figure 9-12 Chirping
Chirping is a high pitched noise that is usually
Drive belts and pulleys wear evenly with use. heard once per revolution of a pulley or belt. It is
Unusual signs of wear indicate some correction is also usually heard at idle and is most common on
needed. The following diagnostic chart (figure 9- cold damp mornings. By squirting water onto a
12) will aid in diagnosing serpentine belt system chirping belt, the noise will momentarily go away.
problems.
Squeal
IMPORTANT: Routine inspection of the belt may Squeal is a loud screeching noise that is usually
reveal cracks in the belt ribs. These cracks will caused by a slipping belt. The noise usually occurs
not impair belt performance and are not a basis when a heavy load is applied to the belt, such as
for belt replacement. If sections of the belt are compressor engagement, accelerating the engine,
missing, the belt should be replaced. Do not or the belt slipping on seized pulley.
use drive belt dressings to extend belt life. Use Whine
of belt dressing will soften the belts and cause Whine is a high pitched continuous noise that may
deterioration. Oil or grease contamination on be caused by a failed bearing.
the belt or pulleys will also deteriorate the belt.

131-084

Figure 9-12 Serpentine Belt Diagnosis Chart

9-12 IES 8/99

Cooling System Diagnosis

Faint Cyclic Rumbling 2. With the pressure cap removed, observe the
Faint cyclic rumbling is a deep low frequency coolant circulating (radiator only). Feel the
noise (once per revolution of the belt). front area of the radiator or heat exchanger for
Pilling cold spots that indicate blockage. Blocked
Pilling is the random accumulation of rubber dust radiators generally occur on units that have
in the bottom of the multi-ribbed belt grooves. A accrued hours (miles) and not on new units.
small amount of pilling is normal. Operation of the 3. Inspect the thermostat to see if it opens.
drive belt system will not be affected unless buildup 4. Inspect the thermostat housing to make sure it
exceeds 1/3 of the belt groove depth. is free of obstructions.
Overheat and/or Noise 5. Remove the coolant pump from the engine
Restrictions in the cooling system can cause and remove the back cover on the pump.
engine overheating and/or cooling system noise. Inspect all internal passages using a flashlight.
6. Inspect the crossover at the front of the intake
Components prone to this condition are the cylin-
manifold. This entire passage can be seen
der head, coolant pump, block, thermostat housing,
only with the thermostat removed.
and intake manifold. Symptoms are:
7. Remove the cylinder heads and check the
• Engine may make snapping/cracking noises. block with a pen light flashlight. Never replace
• Radiator or heater core may gurgle or surge. a block unless the restricted area can be seen.
• Radiator hoses may collapse and expand. 8. Inspect the cylinder heads if the problem is not
• Heater hoses may vibrate and thump. found. Cylinder heads with blocked coolant
passages generally have more than one area
• Overheat lamp may or may not come on.
that is blocked. Look for signs of overheat
Symptoms are caused by coolant boiling at some discoloration (a dark blue or black area). If
localized area and may be noticed after extended none are found, look in the coolant passages
idling and/or while driving. Determine which side of for blockage and probe all accessible
the engine is involved and whether it is at the front passages. The cylinder head is intricate, and
or rear of the engine. all passages cannot be reached. Use a
Inspection substantial wire to go through or around a
partially blocked area. If nothing is found by
1. Isolate the area by probing the engine with a visual inspection and probing, inspect the
sounding bar (large screwdriver). passages for a rough, ragged appearance.
The roughest internal passages are probably
CAUTION the ones that are blocked. Replace a blocked
or suspect cylinder head and inspect the
The pressure cap should be removed from a cool replacement cylinder head before installation.
engine only. If the cap is removed from a hot
cooling system, serious personal injury may
result.

IES 8/99 9-13

Diagnosis INDUSTRIAL ENGINE SYSTEMS

PULLEY INSPECTION (ALL)

Figure 9-13
Examine the pulleys for chips, nicks, tool marks,
cracks, bent sidewalls, corrosion, or other damage.
1. Place a straightedge or position a cord across
the two pulleys so they touch at all points
(figure 9-12).
2. Turn each pulley one half revolution and
recheck with a straightedge or cord. Full
contact at all points must be made. If contact
is not made at all points, the pulley may be
warped or its shaft could be bent. Replace any
parts found to be damaged.
131-085

Figure 9-13 Checking Pulley Alignment

9-14 IES 8/99

Cooling System Service Procedures

SERVICE PROCEDURES
DRAINING AND FILLING THE 4. Place a large top funnel in the radiator fill hole.
COOLING SYSTEM 5. Slowly pour in the coolant. The filling may be
slowed because of the thermostat being
Various methods and equipment can be used. closed.
Draining 6. After the cooling system is filled to 1/2 inch
1. Place a drain pan under the radiator drain below the fill hole, start the engine and let the
cock. cooling system warm up. When the thermo-
stat opens, the coolant level may drop. If the
2. Install a tube on the drain cock. level drops, add coolant until the level is up to
3. Place the end of the tube in the pail or pan. the fill hole.
4. Make sure the cooling system is cool, then 7. Replace the radiator cap.
remove the radiator cap. 8. Check the coolant level in the recovery tank.
5. Open the drain cock completely. Add coolant if needed.
6. Let the cooling system drain until the flow
stops. FLUSHING THE COOLING SYSTEM
7. Place a drain pan under the engine. Various methods and equipment can be used to
flush the cooling system. If special equipment such
8. Remove the drain plug in the engine block.
as a back flusher is used, follow the equipment
9. Let the engine block drain until the flow stops. manufacturer's instructions.
There may be more drainage from the radiator
at this time. NOTICE: If the engine is damaged Internally and a
10. Replace the engine block drain plug. new engine assembly is installed in the vehicle,
make sure all foreign material is completely flushed
11. Close the drain cock.
out of the cooling system. The oil cooler system
Filling should also be flushed out (if equipped). Failure to
rid the oil or cooling system of debris can result in
1. Check the radiator drain cock to be sure it is damage to the replacement engine.
closed.
2. Check the engine drain plug to be sure it is IMPORTANT: Remove the thermostat before
tight. flushing the cooling system.
3. Premix the antifreeze with clear water in 50/50
mixture. COOLANT RECOVERY / SURGE
TANK REPLACEMENT
IMPORTANT: If the old coolant is to be re-used,
check it for glycol/water mix of 50/50. Remove or Disconnect
1. Coolant from the recovery tank.
2. Clamps.
3. Coolant recovery reservoir hose from the
recovery tank.
4. Overflow hose.
5. Bolts.
6. Coolant recovery tank from the vehicle.

IES 8/99 9-15

Service Procedures INDUSTRIAL ENGINE SYSTEMS
Install or Connect
1. Coolant recovery tank to the vehicle.
2. Bolts.
Tighten
• Bolts securely.
3. Coolant overflow hose to the recovery tank.
4. Coolant recovery reservoir hose to the recov-
ery tank.
5. Clamps.
6. Coolant in the recovery tank.

ENGINE COOLANT TEMPERATURE

SENSOR REPLACEMENT
Remove or Disconnect
1. Negative battery cable.
2. Wiring harness connector.
3. Engine coolant temperature sensor.
Install or Connect
1. Engine coolant temperature sensor.
Tighten
• Engine coolant temperature sensor to 23
N•m (17 lbs. ft.).
2. Wiring harness connector.
3. Negative battery cable.

THERMOSTAT REPLACEMENT
131-086
Figure 9-14
Figure 9-14 Thermostat and Components
Remove or Disconnect
1. Drain the cooling system until the radiator Clean
coolant level is below the thermostat.
• Thermostat housing and coolant outlet seal-
2. Bolts or studs. ing surfaces.
3. Coolant outlet. Install or Connect
4. Thermostat from its housing. 1. Thermostat in its housing.
5. Gasket (if necessary). 2. New gasket into position (if necessary).
3. Coolant outlet.
4. Bolt and studs.

9-16 IES 8/99

Cooling System Service Procedures

Tighten Install or Connect

• Bolts and studs to 28 N•m (21 lbs. ft.) on 1. Coolant pump to the engine block.
4.3L and 5.7L engines. 2. New gaskets,
• Studs to 37 N•m (27 lbs. ft.) on 7.4L 3. Bolts.
engines.
Tighten
5. Fill the cooling system.
• Bolts to 41 N•m (30 Lbs. ft.)
6. Start the engine and run with the radiator cap
4. Lower radiator (outlet) hose and heater hose
removed until the radiator upper hose
to the coolant pump. Bypass hose on the 7.4L
becomes hot (thermostat is open).
engine.
7. With the engine idling, add coolant to the radi-
5. Coolant pump pulley and fan to the coolant
ator until the coolant level reaches the bottom
pump hub. Refer to “Fan Replacement.”
of the filler neck.
6. Drive belt. Refer to “Drive Belt Replacement.”
8. Radiator cap to the radiator, making sure the
arrows line up with the overflow tube. 7. Upper fan shroud (if equipped).
9. Check for leaks. 8. Start the engine and run, with the radiator cap
removed, until the upper radiator hose
COOLANT PUMP REPLACEMENT becomes hot (thermostat is open).

Figure 9-15 9. With the engine running, add coolant to the

radiator until the level reaches the bottom of
Remove or Disconnect the filler neck.
1. Coolant from the radiator. 10. Radiator cap, making sure the arrows line up
2. Upper fan shroud (if equipped). with the overflow tube.
3. Drive belt. Refer to “Drive Belt Replacement.” 11. Check for leaks.
4. Fan and pulley from the coolant pump. Refer
to “Fan Replacement.”
5. Lower radiator (outlet) hose and heater hose
from the coolant pump. On the 7.4L engine,
remove the bypass hose.
6. Bolts.
7. Coolant pump from the engine block.
Clean
Mating surfaces on the coolant pump and the
engine block.
600-182

Figure 9-15 Coolant Pump Replacement

IES 8/99 9-17

Service Procedures INDUSTRIAL ENGINE SYSTEMS

DRIVE BELT TENSIONER 3. Idler pulley bolts.

INSPECTION 4. Idler pulley.
5. Bracket bolts.
Figure 9-16
Remove or Disconnect 6. Bracket.
1 Negative battery cable. Install or Connect
2. Serpentine drive belt. Refer to “Serpentine 1. Bracket to cylinder head holes.
Belt Replacement.” 2. Bolts.
3. Position a hex head socket on the belt tension- Tighten
er pulley bolt head.
• Bolts to 66 N•m (49 lbs. ft.).
4. Move the drive belt tensioner through its full
3. Idler pulley.
travel.
4. Bolts.
NOTICE: Do not allow the drive belt tensioner to
snap into the “free” position. This may result in Tighten
damage to the tensioner. • Bolt to 50 N•m (37 lbs. ft.).
Movement should feel smooth and return freely 5. Serpentine drive belt. Refer to “Serpentine
without any binding. If any binding is observed, Belt Replacement.”
replace the tensioner. 6. Negative battery cable.
Install or Connect DRIVE BELT SERVICE (ALL)
1. Serpentine drive belt. Refer to “Serpentine
Maintaining the drive belt and pulleys can extend
Belt Replacement,”
the normal life of a drive belt.
2. Negative battery cable.

DRIVE BELT TENSIONER V-BELT REPLACEMENT

REPLACEMENT When replacing the drive belts, it is essential the
entire set be replaced at the same time. Several
Remove or Disconnect accessories may be driven from the multiple groove
1. Negative battery cable. crankshaft pulley, and the replacement of an inside
2. Serpentine drive belt. Refer to “Serpentine Belt belt will make it necessary to remove the outside
Replacement.” belts first.
3. Bolt. Belt Installation
4. Tensioner.
1. Relieve the belt tension to the position of the
Install or Connect most slack in the belt. It may be necessary to
1. Tensioner to mounting bracket. remove the belts from the outer grooves on the
2. Bolt. accessories first.
Tighten 2. Examine the pulleys. Refer to “Pulley Inspec-
tion.”
• Bolt to 83 N•m (61 lbs. ft.).
3. Serpentine drive belt. Refer to “Serpentine 3. Check the pulley alignment. Refer to “Pulley
Belt Replacement.” Inspection.”
4. Negative battery cable. NOTICE: Do not force a belt into a pulley groove by
prying with a screwdriver, crowbar, or other wedge
IDLER PULLEY AND BRACKET type tool. Prying a belt into position can damage
REPLACEMENT the belt and drive components.

Figure 9-16 4. Install the belt into the pulley grooves by hand.
Remove or Disconnect 5. Position the accessory or the adjusting brack-
1. Negative battery cable. et.
2. Serpentine drive belt. Refer to “Serpentine Belt 6. Check the belt tension. Refer to “V-Belt
Replacement.” Tension Adjustment.”

9-18 IES 8/99

Cooling System Service Procedures

SERPENTINE BELT REPLACEMENT 1. Use a 1/2-inch breaker bar with a socket

placed on the tensioner pulley axis bolt and
Figure 9-16 rotate the tensioner to release belt tension.
The serpentine belt must follow the appropriate 2. Belt.
belt routing. The grooves in the belt must match the Install or Connect
grooves in the pulleys. The tensioner is spring
1. Route belt over all the pulleys except the belt
loaded and will return to the tension position when
tensioner.
released.
2. Use a 1/2-inch breaker bar with a socket
Remove or Disconnect placed on the tensioner pulley axis bolt and
rotate the tensioner to the released position.
NOTICE: Do not allow the drive belt tensioner to
snap into the “free” position. This may result in 3. Belt over the belt tensioner pulley.
damage to the tensioner. 4. Check the belt for correct “W groove tracking”
around each pulley.

131-087

Figure 9-16 Serpentine Belt System

IES 8/99 9-19

Service Procedures INDUSTRIAL ENGINE SYSTEMS

BELT TENSION ADJUSTMENT (ALL) RADIATOR SERVICE

Drive belts must grip the entire contact area of the Radiator Internal Deposits
pulley. When drive belts are too loose, the belts can
A radiator with a dirty, obstructed, or leaking core
slip, tear, burn, or grab and snap. More belts fail
will cause the engine to overheat. A scale deposit
from being too loose than too tight.
inside the radiator is a result of using hard, high
Belts that are too tight can damage the engine by mineral content water in the cooling system. The
causing side loading of the crankshaft, crankshaft effect of heat on the minerals in the water causes
bearings, and accessories or accessory bearings. the formation of scale, or hard coating, on metal
Too much belt tension will also stretch and weaken surfaces within the radiator, thereby reducing the
the belts. transfer of heat. Some hard water will produce a
After a belt has made one complete revolution it is silt-like deposit which restricts the flow of water.
considered used and should be adjusted to the Replace a radiator that is plugged or has a heavy
used belt tension specification. When the drive scale on the core.
belts are worn, they should be replaced. Tightening Scale Removal
worn drive belts will not prevent slipping and can
cause damage to the engine. To remove the hardened scale, a direct chemical
action is necessary. A flushing compound at the
Do not use belt dressings to extend belt life. Most specified rate of 30 grams per liter (4 oz. per gallon)
dressings contain chemicals that soften the belts. of radiator capacity should be added to the coolant
Check the belts at 1500 hour intervals. Also check solution in the form of a dissolved solution while the
all necessary mounting or adjusting bracket bolts. engine is running. Operate the engine for 15
Tighten as necessary. minutes or until it reaches normal operating temper-
Adjust ature, then drain and flush the system with clean
water.
Tool Required:
• BT-33-95 ACBN Belt Tension Gage There are various types of flushing compounds
commercially available, but they should be obtained
IMPORTANT: Belts with an idler pulley and two from a reliable source. Most compounds attack
pulleys are adjusted to the “two-pulley” tension. metals and should not remain in the engine for
Use BT-33-95 ACBN placed at the center of the more than a few minutes. A neutralizer should be
greatest span to check the belt tension. used in the cooling system immediately after a
Tension on a new V-belt with two pulleys to 400- descaling solvent is used. For extremely hard,
440 N (90-100 lbs.). With three or more pulleys stubborn coatings, such as lime scale, use a
(not including an idler pulley), adjust the stronger solution. The corrosive action of a
tension to 530-620 N (120-140 lbs.). stronger solution will affect the thin metals of the
• Tension on a used V-belt with two pulleys to radiator, thereby reducing its operating life. A
350-400 N (80-90 lbs.). complete flushing and rinsing is mandatory and
must be accomplished skillfully.
• With three or more pulleys (not including an
idler pulley), adjust the tension to 530-620 N After the solvent and neutralizer have been used
(120-140 Lbs.). and the cooling system is flushed, drain the entire
• Tension on a new serpentine belt to 100 N per system and fill it with clean, soft water plus a high
rib (25 lbs. per rib). boiling type antifreeze that meets GM 6038-M spec-
ifications. After filling the cooling system, check for
• Tension on a used serpentine belt to 90 N per radiator, hose, and engine coolant leaks.
rib (21 lbs. per rib).

9-20 IES 8/99

Cooling System Service Procedures

HEAT EXCHANGER SERVICE Cleaning Engine Coolant Section

Cleaning External Water Section The engine coolant section of the cooling system
should be cleaned at least once every two years, or
Cooling efficiency of an engine with fresh water is whenever decreased cooling efficiency is experi-
greatly dependent upon heat transfer through the enced.
tubes within the heat exchanger. During engine
operation, contaminants within the raw water (such A good grade of automotive cooling system clean-
as silt, lime, etc.) collect on the inside of the tubes, ing solution may be used to remove rust, scale, or
thus reducing heat transfer and greatly decreasing other foreign material. Manufacturer's instructions,
heat-exchanger efficiency. It is therefore recom- which accompany a particular cleaner, should
mended that the raw-water section of the heat always be followed.
exchanger be cleaned at least once every two If the fresh-water section is extremely dirty, a
years, or whenever decreased cooling efficiency is pressure-flushing device may be used to flush out
suspected, as follows: the remaining deposits. The flushing should be
1. Remove the raw-water drain plug from the done in a direction opposite the normal coolant flow
bottom of the heat exchanger and allow water to allow water to get behind deposits and force
to drain. After water has drained completely, them out. Refer to instructions which accompany
coat the threads of the drain plug with Perfect the flushing device for proper hookup and flushing
Seal® (or equivalent) and reinstall. procedure.
2. Remove the bolts which secure the end plates
to each end of the heat exchanger, then
COOLANT HOSE REPLACEMENT
remove the end plates, seal washers, and Remove or Disconnect
gaskets. Clean gasket material from end 1. Drain the cooling system.
plates and heat exchanger.
2. Hose supports (if equipped).
3. Clean water passages in heat exchanger by
inserting a suitably sized wire brush into each 3. Hose clamps from the inlet and outlet hoses.
passage. Use compressed air to blow loose 4. Radiator inlet hose.
particles out of the water passages. 5. Radiator outlet hose.
4. Apply Perfect Seal® (or equivalent) to both Install or Connect
sides of the new end-plate gaskets, then rein-
1. Radiator outlet hose.
stall end plates using new gaskets and seal
washers. (Be sure to install seal washers 2. Radiator inlet hose.
between end plates and gaskets.) 3. Clamps to the radiator inlet and outlet hoses.
5. Start engine and inspect cooling system for Tighten
leaks. • Screw type clamps to 3 N•m (27 lbs. in.).
4. Hose support bolts to inlet hose (if equipped).
Tighten
• Bolts securely.
5. Fill the cooling system to the proper level.
Check for leaks.

IES 8/99 9-21

Service Procedures INDUSTRIAL ENGINE SYSTEMS

FAN REPLACEMENT Install or Connect

Figure 9-17
CAUTION
Remove or Disconnect
1. Radiator fan shroud. Do not repair and reuse a fan with a bent,
cracked, or damaged blade. Replace the fan as
2. Fan to pulley attaching bolts
an assembly. A damaged blade can change the
Inspect balance of the fan. A fan out of balance or
Inspect the mating surfaces (the coolant cracked could fly apart during use and cause
pump hub and the fan hub) for smoothness. personal injury or damage to the vehicle.
Rework as necessary to eliminate any burrs
other imperfections. 1. Fan to pulley.
2. Bolts.
Tighten
• Bolts to 24 N•m (18 lbs. ft.).
3. Fan shroud.

131-169

Figure 9-17 Fan and Components (Typical)

9-22 IES 8/99

INDUSTRIAL ENGINE SYSTEM Service Procedures

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IES 131 8/99 9-23

ServiceProcedures INDUSTRIAL ENGINE SYSTEMS

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6-26 IES 131 8/98

3.0L Table of Contents

NOTICE: Always use the correct fastener in the proper location. When you replace a fastener, use
ONLY the exact part number for that location. Fasteners that require replacement will be called out.
Fasteners that require thread lockers or thread sealant will also be called out. UNLESS OTHERWISE
SPECIFIED, do not use supplement coatings (paints, greases, or other corrosion inhibitors) on
fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When you install fasteners, use the correct tighten-
ing sequence and torque specification. Following these instructions can help you avoid damage to
parts and systems.

TABLE OF CONTENTS
General Description .......................................10-1 Cylinder Block Plug Replacement ...............10-15
Crankshaft Inspection ..................................10-15
General Information .......................................10-3 Connecting Rod Side Play and Bearing
Statement on Cleanliness and Care..............10-3 Clearance Measurement ..........................10-17
Use of RTV Sealer and Anaerobic Gasket Connecting Rod and Piston Inspection .......10-18
Eliminator....................................................10-3 Assemble Connecting Rod and Piston........10-21
Replacing Engine Gaskets ............................10-4 Measure Main Bearing Clearance...............10-22
Thread Repair................................................10-4 Camshaft Inspection ....................................10-23
Disassembly of Engine..................................10-5 Camshaft Bearing Removal.........................10-25
Intake/Exhaust Manifold Inspection.............10-25
Tools and Shop Equipment ...........................10-5
Rocker Arm and Pushrod Inspection...........10-26
Accessory Removal .......................................10-5
Rocker Arm Stud Replacement ...................10-26
Cleaning.........................................................10-5
Disassemble Cylinder Head ........................10-27
Draining the Engine .......................................10-5
Cylinder Head Cleaning...............................10-27
Flywheel and Housing Removal....................10-6
Cylinder Head Inspection ............................10-28
Oil Filter Bypass Valve Removal ...................10-6
Cylinder Head Reconditioning .....................10-29
Intake/Exhaust Manifold Removal .................10-6
Assemble Cylinder Head .............................10-30
Coolant Pump Removal.................................10-6
Disassemble Hydraulic Lifter .......................10-31
Torsional Damper Removal ...........................10-6
Assemble Hydraulic Lifter............................10-32
Front Cover and Crankshaft
Seal Removal .............................................10-7 Disassemble Oil Pump ................................10-32
Rocker Arm Cover Removal..........................10-7 Oil Pump Inspection ....................................10-33
Camshaft Lobe Lift Measurement .................10-7 Assemble Oil Pump .....................................10-33
Rocker Arm and Pushrod Removal...............10-8 Assembly of Engine.....................................10-35
Cylinder Head Removal.................................10-8 Prior to Assembly ........................................10-35
Hydraulic Lifter Removal ...............................10-8 Crankshaft Installation .................................10-35
Oil Pan Removal............................................10-9 Camshaft Bearing Installation......................10-36
Rear Crankshaft Oil Seal and Retainer Camshaft Installation ...................................10-37
Removal......................................................10-9 Connecting Rod and Piston Installation ......10-37
Oil Pump Removal.........................................10-9 Oil Pump Installation....................................10-39
Connecting Rod and Piston Removal ...........10-9 Rear Crankshaft Oil Seal Installation ..........10-39
Camshaft Removal ......................................10-12 Oil Pan Installation.......................................10-40
Crankshaft Removal ....................................10-12 Rear Crankshaft Oil Seal Retainer
Cleaning, Inspection, and Repair ...............10-13 Installation.................................................10-40
Clean and Inspect Cylinder Block ...............10-13 Hydraulic Lifter Installation ..........................10-41
Repair Cylinder Block ..................................10-14 Cylinder Head Installation............................10-41
Boring .......................................................10-14 Rocker Arm and Pushrod Installation..........10-41
Honing ......................................................10-14
IES 131 8/99 10-i
Table of Contents INDUSTRIAL ENGINE SYSTEMS

TABLE OF CONTENTS (CONTINUED)

Adjust Valves ...............................................10-42 Flywheel Installation ....................................10-44
Rocker Arm Cover Installation.....................10-42 Engine Setup and Testing ...........................10-45
Front Cover and Crankshaft Seal
Engine Torque Specifications .....................10-47
Installation.................................................10-42
Torsional Damper Installation ......................10-43 Engine Specifications ..................................10-48
Coolant Pump Installation............................10-44
Special Tool Usage.......................................10-50
Intake/Exhaust Manifold Installation ............10-44
Oil Filter Bypass Valve Installation ..............10-44

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GeneralhDescription INDUSTRIAL ENGINE SYSTEMS

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10-iii IES 131 8/98

3.0L General Description

GENERAL DESCRIPTION
Figure 10-1 The main gallery supplies pressure oil to the
camshaft bearings and main bearings. Oil flows to
Engine operation is the same as any typical inter-
the connecting rod bearings through holes drilled in
nal combustion gasoline engine.
the crankshaft. From the front camshaft bearing, oil
The pressurized lubrication oil is supplied by a flows to the timing gear oil nozzle for gear lubrica-
gear pump mounted on the rear main bearing cap. tion. Pressurized oil is also routed to the lifters.
The distributor, driven by a helical gear on the
The hydraulic valve lifters supply oil through
camshaft, also drives the gear oil pump. A spring
hollow pushrods to the rocker arms. Oil from the
type pressure regulating valve controls the system
camshaft, crankshaft and timing cover returns to the
oil pressure.
oil pan to repeat the cycle.
Oil flows from the pump to a full flow oil filter and
to the main oil gallery. If oil filter becomes restricted,
the filter by-pass valve opens, allowing oil to contin-
ue to flow to gallery for engine lubrication. The main
oil gallery is drilled the length of the block above the
camshaft.

IES 131 8/99 10-1

General Description INDUSTRIAL ENGINE SYSTEMS

131-001

Figure 10-1 Engine Lubrication Diagram

10-2 IES 131 8/99

3.0L General Information

GENERAL INFORMATION
STATEMENT ON CLEANLINESS Using RTV Sealer
AND CARE 1. Do not use RTV when extreme temperatures
are expected, such as exhaust manifold, head
An engine is a combination of many machined,
gasket or where gasket eliminator is specified.
honed, polished, and lapped surfaces with very fine
tolerances. 2. When separating components sealed with
RTV, use a rubber mallet and “bump” the part
Whenever valve train components, cylinder head, sideways to shear the RTV sealer. “Bumping”
cylinder, crankshaft, or connecting rod components should be done at bends or reinforced areas to
are removed for service, they should be retained in prevent distortion of parts. RTV is weaker in
order. At the time of installation, they should be shear (lateral) strength than in tensile (vertical)
installed in the same locations and with the same strength.
mating surfaces as when removed.
Any time the air cleaner or TBI unit is removed, NOTICE: Attempting to pry or pull components
the intake opening must be covered. This will apart may result in damage to the part.
protect against the entrance of foreign material 3. Surfaces to be resealed must be clean and
which could follow the intake passage into the cylin- dry. Remove all traces of oil and RTV with a
der and cause extensive damage when the engine chlorinated solvent (GM P/N 1050454 or
is started. equivalent). Do not use petroleum cleaners
When any internal engine parts are serviced, care such as mineral spirits. They leave a film onto
and cleanliness are important. A liberal coating of which RTV will not stick.
engine oil should be applied to friction areas during 4. Apply RTV to one of the clean surfaces. Use
assembly to protect and lubricate the surfaces on a bead size as specified in the procedure. Run
initial operation. Throughout this Section, it should the bead to the inside of any bolt holes. Do not
be understood that proper cleaning and protection allow the sealer in any blind threaded holes, as
of machined surfaces and friction areas is part of it may prevent the bolt from seating properly or
the repair procedure. This is considered standard cause damage when the bolt is tightened.
shop practice even if not specifically stated.
5. Assemble while RTV is still wet (within 3
minutes). Do not wait for RTV to skin over.
USE OF RTV SEALER AND
6. Torque bolts to specifications. Do not over-
ANAEROBIC GASKET ELIMINATOR torque.
Two types of sealer are commonly used in the Using Anaerobic Gasket Eliminator
engines covered by this manual. These are RTV
sealer and anaerobic “gasket eliminator” sealer. It 1. Clean surfaces to be resealed with a chlorinat-
is important that these sealers be applied properly ed solvent (GM P/N 1050454 or equivalent) to
and in their proper place to prevent oil leaks. THE remove all oil, grease, and old material.
TWO TYPES OF SEALERS ARE NOT INTER- 2. Apply a continuous bead of gasket eliminator
CHANGEABLE. Use the sealer recommended in to one flange.
the procedure. 3. Spread the bead evenly with your finger to get
RTV (room temperature vulcanization) sealer is a uniform coating on the complete flange.
used where a non-rigid part is assembled to a rigid 4. Assemble parts in the normal manner and
part. Common examples are oil pans and rocker torque immediately to specifications.
covers. Anaerobic gasket eliminator hardens in the
absence of air. This sealer is used where two rigid IMPORTANT: Anaerobic sealed joints that are
parts (such as castings) are assembled together. partially torqued and allowed to cure more than
When two rigid parts are disassembled and sealer five minutes may result in incorrect shimming
or gasket is readily noticeable, the parts were prob- of the joint.
ably assembled using gasket eliminator.

IES 131 8/99 10-3

General Information INDUSTRIAL ENGINE SYSTEMS

REPLACING ENGINE GASKETS 1. Determine size, pitch, and depth of damaged

thread. If necessary, adjust stop collars on
cutting tool and tap to required depth.
CAUTION
IMPORTANT: Refer to the kit manufacturer's
Composite type gaskets are used in some areas instructions regarding the size of drill and tap to
of the engine assembly. These gaskets have a be used.
thin metal core. Use caution when removing or 2. Drill out damaged thread.
handling composite gaskets to help avoid
personal injury. 3. Tap hole. Lubricate tap with light engine oil.
Clean the thread.

THREAD REPAIR IMPORTANT: Avoid build-up of chips. Back out

the tap every few turns and remove chips.
Figure 10-2
4. Thread the thread insert onto the mandrel of
Tool Required: the installer. Engage the tang of the insert on
• General purpose thread repair kits are avail- the end of the mandrel.
able commercially. 5. Lubricate the insert with light engine oil (except
Damaged threads may be reconditioned by when installing in aluminum) and install.
drilling out, rethreading, and installing a suitable
IMPORTANT: When correctly installed, the
thread insert.
insert should be flush to one turn below the
surface.
CAUTION 6. If the tang of the insert does not break off when
backing out the installer, break the tang off with
Wear safety glasses to avoid eye damage.
a drift.

600-177

Figure 10-2 Repairing Thread Holes

10-4 IES 131 8/99

3.0L Disassembly of Engine

DISASSEMBLY OF ENGINE
English and Metric Fasteners • Starter Motor
• Carburetor / Mixer Components
CAUTION It is beyond the scope of this Section to cover in
detail the many different accessory installations.
Late model engines use a combination of English Refer to the appropriate service manual section for
and Metric threaded fasteners. The components this information.
effected are starter motor, engine mounts, and
Diagrams of emissions and vacuum hose rout-
flywheel housing mounting. Verify that the prop-
ings, wiring harness routing, accessory drive belt
er fasteners are used whenever removing or
layout, etc. should be made before removing acces-
replacing one of these components.
sories.

TOOLS AND SHOP EQUIPMENT CLEANING

A clean, well lit work area should be available. It is important that the engine be as clean as
Other necessary aides include: a suitable parts possible to prevent dirt from entering critical areas
cleaning tank, compressed air supply, trays to keep during disassembly.
parts and fasteners organized, and an adequate set
Remove the engine accessories before cleaning
of hand tools.
to provide better access to engine exterior surfaces.
An approved engine repair stand will help prevent Cover the openings with tape to prevent the entry of
personal injury or damage to the engine compo- coolant, solvent and dirt.
nents.
Methods used to clean the engine will depend on
Special tools are illustrated throughout this the equipment available. Steam cleaning, pressure
Section, and listed at its end. These tools (or their washing or solvent cleaning are some acceptable
equivalents) are specially designed to quickly and methods. Allow the engine to dry before beginning
safely accomplish the operations for which they are the work.
intended. The use of these tools will also minimize
possible damage to engine components. DRAINING THE ENGINE
Some precision measuring tools are required for Remove or Disconnect
inspection of certain critical components. Torque 1. Oil pan drain plug, and allow oil to drain from
wrenches are necessary for the correct assembly of the oil pan.
various parts.
2. Oil filter.
ACCESSORY REMOVAL 3. Coolant drain plugs from block and allow to
drain.
The various procedures in this manual assume
that the engine accessories have been removed. Install or Connect
These accessories may include one or more of the NOTICE: Refer to “Notice” on page 1.
following:
1. Oil pan drain plug.
• Hydraulic Pump
Tighten
• Drive Belt Tensioner
• Drain plug to 45 N•m (33 lb. ft.).
• Generator
2. Coolant drain plugs.
• Air Conditioning Compressor
• Cooling Fan IMPORTANT: If cleaning or repairing engine
block, do not install new drain plugs or the oil
• Distributor filter until assembly of the engine block. Refer
• Accessory Mounting Brackets to “Engine Block Servicing” in this Section.

IES 131 8/99 10-5

Disassembly of Engine INDUSTRIAL ENGINE SYSTEMS
Tighten
• Coolant drain plug to 15 N•m (11 lb. ft.).

FLYWHEEL AND HOUSING

REMOVAL
Figures 10-3 and 10-4
Remove or Disconnect
1. Bolts to remove flywheel cover and gasket
(figure 10-3).
2. Bolts and nut.
3. Flywheel-to-crankshaft bolts to remove
131-098
flywheel (figure 10-4).
Figure 10-4 Flywheel Bolts
4. Check flywheel for worn or missing teeth.

OIL FILTER BYPASS VALVE INTAKE/EXHAUST MANIFOLD

REMOVAL REMOVAL
Remove or Disconnect Remove or Disconnect
1. Oil filter. 1. Manifold bolts.
2. Check spring and fiber bypass valve for 2. Manifold and gasket.
smooth operation and cracked or damaged
valve or spring. COOLANT PUMP REMOVAL
3. Bypass valve by prying valve from engine Remove or Disconnect
block using a screwdriver. 1. Coolant pump pulley bolts.
2. Coolant pump pulley.
3. Coolant pump bolts.
4. Coolant pump and gasket.
Clean
• Coolant pump gasket surfaces.

TORSIONAL DAMPER REMOVAL

Figure 10-5
Tool Required:
J 39046 Torsional Damper Puller and Installer

CAUTION
DO NOT use a universal claw type puller to
remove torsional damper. Pulling on the outer
inertia weight can damage damper by separating
the bonded rubber from the center hub.

Remove or Disconnect
131-099
1. Torsional damper and key using J 39046.
Figure 10-3 Flywheel Cover Components

10-6 CENG 131 8/98

3.0L Disassembly of Engine

ROCKER ARM COVER REMOVAL

Figure 10-7
Remove or Disconnect
1. Positive Crankcase Ventilation (PCV) hose.

CAUTION
DO NOT pry cover to remove cover from cylinder
head. Cover can be warped or damaged. Tap
cover loose with the heal of your hand or use a
rubber mallet.
131-011

Figure 10-5 Removing Torsional Damper 2. Bolts (3) and reinforcements (4) to remove
rocker arm cover (2) and gasket (5).
FRONT COVER AND CRANKSHAFT
SEAL REMOVAL
Figure 10-6

NOTICE: The front crankshaft seal can be

removed from the cover without removing the cover
from the engine. Use care not to distort the cover
when prying the seal from the cover. Follow steps
2 and 3.
Remove or Disconnect 131-100
1. Bolts to remove front cover and gasket. Figure 10-7 Rocker Arm Cover
2. Front crankshaft seal (1) using a screwdriver
to pry seal from cover. Use care not to distort
the cover.
CAMSHAFT LOBE LIFT
3. Inspect front cover for distortion or damage;
MEASUREMENT
replace if necessary. Figure 10-8
Tool Required:
J 8520 Dial Indicator (or equivalent)
Measure
1. Camshaft lobe lift using the following proce-
dures:
A. Fasten a dial indicator (such as J 8520) to
the engine, so the plunger of the indicator
rests on the end of the pushrod. Be sure the
pushrod is in the socket of the lifter.
B. Turn the crankshaft slowly in the direction of
rotation (counterclockwise at the flywheel
131-090
end), until the lifter is on the heel (lowest
Figure 10-6 Front Cover and Crankshaft Seal position) of the camshaft lobe.
C. Set the dial indicator to zero, and turn the
crankshaft until the lifter and pushrod are at
the highest position of the camshaft lobe.

IES 131 8/99 10-7

Disassembly of Engine INDUSTRIAL ENGINE SYSTEMS

CYLINDER HEAD REMOVAL

Figure 10-10
Remove or Disconnect
1. Cylinder head bolts (1) to remove cylinder
head (2) and gasket (3).

131-091

Figure 10-8 Measuring Camshaft Lobe Lift

D. Record the maximum lift of the pushrod and

compare with the specification.
131-101
• Camshaft lobe lift
Figure 10-9 Rocker Arm and Pushrod
- Intake - 6.42 +/- 0.03 mm
(0.253 +/- 0.001 in.)
- Exhaust - 6.42 +/- 0.03 mm
(0.253 +/- 0.001 in.)
2. Repeat Steps A-D for each pushrod. Replace
camshaft if not within specification.

ROCKER ARM AND PUSHROD

REMOVAL
Figure 10-9
Remove or Disconnect

CAUTION 131-102

Figure 10-10 Cylinder Head and Gasket

Keep each rocker arm, rocker arm components
and pushrod together as a set. If the parts are not HYDRAULIC LIFTER REMOVAL
to be replaced, they must be installed in the
same location from which they were removed. Figures 10-11 and 10-12
Tools Required:
1. Rocker arm nut (1), rocker arm (2), ball (3) and
J 3049 Plier Type Hydraulic Lifter Remover
pushrod (4).
J 9290-01 Slide Hammer Type Hydraulic Lifter
NOTICE: If only the pushrod is to be replaced, Remover
loosen the nut only enough to move the rocker arm Remove or Disconnect
out of the way. Pushrod can then be lifted out.
NOTICE: If hydraulic lifter is stuck, use J 3049 Plier
Type (1) or J 9290-01 Slide Hammer Type (2)
Hydraulic Lifter Remover to remove lifter.

10-8 IES 131 8/99

3.0L Disassembly of Engine

OIL PAN REMOVAL

Figure 10-13
Remove or Disconnect
1. Remove oil pan bolts (1 and 2), and nuts (3).
2. Remove oil pan (4) and gasket (5).

131-092

Figure 10-11 Plier Type Lifter Remover

131-105

Figure 10-13 Oil Pan, Gaskets, and Seal

REAR CRANKSHAFT OIL SEAL AND

RETAINER REMOVAL
131-093 Figures 10-14 and 10-15
Figure 10-12 Slide Hammer Type Lifter Remover
NOTICE: If rear crankshaft oil seal is the only item
to be serviced, proceed to Step 3.
1. Remove hydraulic lifters (3) using a magnet or
special tools, one at a time to keep them in 1. Remove seal retainer and nuts (figure 10-14).
order. Lifters must be installed in the same 2. Remove seal retainer and gasket (figure 10-
bore from which they were removed. 14).
2. Inspect hydraulic lifters:
A. If the lifter body is scored or scuffed, inspect CAUTION
the mating bore of the cylinder block;
replace parts as necessary. If the rear crankshaft oil seal is removed while on
the engine, use care when removing the oil seal
B. Inspect pushrod seat of lifter if seat is
so not to nick the crankshaft sealing surface.
scuffed or worn, inspect the mating pushrod
end; replace parts as necessary.
3. Insert screwdriver into notches of seal retainer
C. Check clearance between lifter and its and pry the seal from the seal retainer (figure
mating bore. 10-15).
D. Check the lifter foot for a smooth and slightly
convex surface. If the foot is scored, pitted or
extremely worn, check the mating camshaft
lobe also; replace parts as necessary.

IES 131 8/99 10-9

Disassembly of Engine INDUSTRIAL ENGINE SYSTEMS

OIL PUMP REMOVAL

Figure 10-16
Remove or Disconnect
1. Remove oil pickup tube bolts (1).
2. Remove oil pump-to-crankcase bolts (2) to
remove oil pump and pickup tube assembly.

131-106

Figure 10-16 Oil Pump

CONNECTING ROD AND PISTON

REMOVAL
Figures 10-17 through 10-20
600-210
Tool Required:
Figure 10-14 Rear Crankshaft Oil Seal Retainer J 24270 Ridge Reamer
J 5239 Connecting Rod Guide Set
Remove or Disconnect
1. Remove any ridges or deposits from the upper
end of the cylinder bores using a ridge reamer
and the following procedure:
A. Turn the crankshaft until piston to be
removed is at the bottom of its stroke.
B. Put a cloth on top of piston (figure 10-17).
C. Remove ridge or deposits using a ridge
reamer (figure 10-18). Follow the instruc-
tions furnished by the tool manufacturer.
D. Turn the crankshaft until the piston is at the
top of its stroke and remove cuttings and
600-247
cloth.
Figure 10-15 Seal Removal Notches
E. Repeat Steps A-D for each piston to be
removed.

10-10 IES 131 8/99

3.0L Disassembly of Engine

2. Remove nuts (2) to remove connecting rod

cap (1) (figure 10-20).
3. Install J 5239 Rod Guide Set on connecting
rod studs to protect journal surfaces (figure 10-
21). Push connecting rod and piston assembly
out the top of the cylinder block using the long
guide rod tool.
4. Take care not to contact crank journals.

NOTICE: It will be necessary to turn the crankshaft

131-107
slightly to disconnect and remove some of the
Figure 10-17 Cloth Inside Cylinder Bore piston and connecting rod assemblies.
5. Repeat Steps 2 through 4 to remove remaining
pistons and connecting rods assemblies.

600-207

Figure 10-18 Removing Cylinder Ridge

CAUTION
131-109

The connecting rod and cap must be kept togeth- Figure 10-20 Connecting Rod Cap
er as a set. Check the connecting rod and cap for
identification marks; mark the parts if necessary
(figure 10-19) so parts can be installed in the
same position as removed.

131-108

Figure 10-19 Connecting Rod Identification

Marking Area

600-208

Figure 10-21 Using J 5239 Rod Guide Set

IES 131 8/99 10-11

Disassembly of Engine INDUSTRIAL ENGINE SYSTEMS

CAMSHAFT REMOVAL CRANKSHAFT REMOVAL

Figure 10-22 Figure 10-19
Remove or Disconnect Remove or Disconnect
1. Turn crankshaft to align timing marks (1) on
timing gears. CAUTION
2. Remove two camshaft thrust plate bolts
through holes in gears (2). The connecting rod caps and main bearing caps
must be installed in their original positions. Check
3. Carefully remove timing gear and camshaft
the bearing caps for location marks; mark the
assembly so as not to damage camshaft bear-
caps if necessary (refer to figure 10-19), so caps
ings.
can be installed in the same position as removed.

1. Remove bolts to remove main bearing caps.

Carefully lift crankshaft from engine block.

131-110

Figure 10-22 Timing Gear Alignment Marks

10-12 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

CLEANING, INSPECTION, AND REPAIR

CLEAN AND INSPECT CYLINDER Measure
BLOCK • Measure cylinder walls for taper, out-of-round
or excessive ridge at the top of ring travel
Figures 10-23 and 10-24 using a cylinder bore gauge (figure 10-24).
Remove or Disconnect A. Adjust gauge so thrust pin must be pushed
1. Make sure all components are removed from in about 6.5 mm (0.250 in.) to put indicator
engine block (figure 10-23). into bore.
B. Put gauge in the middle of the bore and turn
dial to “0”.
C. Carefully move the gauge up and down
cylinder to determine out-of-round and taper
conditions.

131-111

Figure 10-23 Cylinder Block

Clean
• Wash cylinder block thoroughly with clean-
ing solvent. Remove old gasket material
from machined surfaces.
2. Remove all oil gallery plugs.
Clean
• All oil passages.
• All water passages.
Inspect 600-155

• All water passages. Figure 10-24 Measuring Cylinder Bore

• Cylinder block for cracks in the cylinder
walls, water jacket, valve lifter bores and NOTICE: If cylinder bores exceed specifications,
main bearing webs. Replace the block if replace cylinder block or have cylinders rebored by
cracks are present. a qualified machine shop. If cylinder is rebored,
oversize piston and rings must be installed.
NOTICE: Minute cracks not visible to the naked
eye may be detected by applying a mixture of one Measure
part kerosene and three parts light engine oil to any • Cylinder block bores
suspected areas. Wipe the part dry and apply a thin - Diameter 101.59 - 101.66 mm
layer of zinc oxide dissolved in wood alcohol. If (3.9995 - 4.0025 in.)
cracks are present, the cracked area will be discol-
ored. Or, send block to be magnafluxed by a quali- - Maximum Taper 0.025 mm
fied machine shop. (0.001 in.)
- Maximum Out-of-Round 0.05 mm
(0.002 in.)

IES 131 8/99 10-13

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS

REPAIR CYLINDER BLOCK Honing

The following operations depend upon the condi- 1. Follow the hone manufacturer’s instructions for
tion of the engine block: use of the hone, cleaning and lubrication
during operation.
BORING and HONING must be done if the cylin-
der block inspection indicated that the block was
suitable for continued use except for out-of-round or CAUTION
tapered cylinders.
DO NOT force piston through the cylinder until
NOTICE: Boring should only be carried out by a the cylinder has been honed to the correct size.
qualified machine shop with quality equipment or This can cause the piston to be distorted. Handle
severe damage can be done to cylinder block. the piston with care.
HONING can be done if the cylinders were found 2. Occasionally during the honing operation, thor-
to have less than 0.13 mm (0.005 in.) taper or wear oughly clean the cylinder bore and check the
and then fitted with the high limit standard size selected piston for correct fit.
piston. A cylinder bore may not entirely clean up
when fitted to a high limit piston. If it is desired to 3. When finish-honing a cylinder bore to fit a
entirely clean up the bore, it will be necessary to piston, the hone should be moved up and
bore and hone cylinder to fit the smallest oversized down at a sufficient speed to obtain very fine,
piston. uniform surface finish marks in a crosshatch
pattern approximately 45° to 65°. Finish marks
Honing is always performed on cylinder block should be clean but not sharp, free from
when new piston rings are installed or following a imbedded particles and torn or folded metal.
bore job.
4. Permanently mark the piston for the cylinder to
When pistons are being fitted and honing is not which it has been fitted. Continue to hone
necessary, cylinder bores must be cleaned with hot remaining cylinders and fit pistons.
water and detergent. Wipe the bore several times
with a clean cloth and engine oil. CAUTION
PISTON SELECTION requires careful checks to
ensure the proper piston clearance is maintained. It is important that a good cleaning operation is
performed following any machining process. Any
Boring: abrasive material remaining in the bore will cause
1. Before using any type boring bar, the top of the premature engine wear in cylinders and bear-
cylinder block should be filed off to remove any ings.
dirt or burrs. This is important to prevent the
boring bar from tilting, which can result in the 5. Thoroughly clean the cylinder bores with hot
rebored cylinder wall not being at right angle to water and detergent. DO NOT use kerosene or
the crankshaft. gasoline to clean cylinders. Scrub bores with a
stiff brush and rinse thoroughly with hot water.
2. Measure the piston to be fitted using a microm-
Swab the cylinder bores several times with
eter, at the center of the piston skirt and
light engine oil on a clean cloth. Wipe bores
perpendicular to the piston pin.
with a clean cloth. Clean the remainder of the
3. Carefully follow the manufacturer’s instructions cylinder block to remove any abrasive material
of the boring equipment being used. left from the honing operation.
4. Bore the cylinder to the same diameter as the
piston. Hone (the next operation) the cylinder
to obtain the specified clearance.

10-14 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

Piston Selection
1. Check the used piston to cylinder bore clear-
ance as follows:
A. Measure the cylinder bore diameter with a
telescoping gauge, approximately 57 mm
(2.25 in.) from the top of the cylinder bore.
B. Measure the piston diameter at the piston
skirt, approximately 64 mm (2.5 in.) from the
top of the piston and perpendicular to the
piston pin.
C. Subtract the piston diameter from the cylin- 131-112

der diameter to determine the piston clear- Figure 10-25 Cylinder Block Plug Installation Tool
ance.
D. Find the piston clearance on the chart and CRANKSHAFT INSPECTION
determine if the piston clearance is in the
acceptable range. Figures 10-26 through 10-28
2. If the used piston is not acceptable, check if a Tools Required:
new or oversized piston can be selected to fit J 4420 Crankshaft Gear Remover
the cylinder bore within the acceptable range. J 5590 Crankshaft Gear Installer
3. If the cylinder bore must be reconditioned, Clean
measure the new piston diameter at the piston
• Crankshaft in cleaning solvent and dry with
skirt, perpendicular to the piston pin. Hone the
compressed air. Make sure all oil passages
bore to the correct clearance range.
are clear.
4. Mark the piston to identify the cylinder for
Inspect
which it was fitted.
• Crankshaft for gouges, chips, cracks or discol-
CYLINDER BLOCK PLUG oration (overheating); replace crankshaft as
necessary.
REPLACEMENT
Figure 10-25
Remove or Disconnect
1. Drill a hole in the center of the plug (1).
2. Plug using a drift punch to pry the plug out.
Inspect
• Inspect the plug bore for any damage that
would cause the replacement plug to leak.
Repair the damage by boring to the diameter
for the next oversize plug.
Install or Connect
1. Apply Sealing Compound (GM part no.
1052080) or equivalent to the plug and bore. 600-243

2. Pull the sealing edge (2) of the plug into the Figure 10-26 Measuring Crankshaff Main Bearing
block using an installing tool (3). The tool must Journal / Diameter
not contact the flange. This may damage the
sealing edge causing a leak or plug blowout.
The flanged edge must be below the cham-
fered edge of the bore to seal.

IES 131 8/99 10-15

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS
Measure Inspect
• Measure crankshaft main bearing journal • Inspect crankshaft gear for wear or damage. If
diameter in several places, approximately 60° gear must be replaced, use the following
apart (figure 10-26). Check also for tapered or procedure:
out-of-round journals. Calculate the average of A. Remove gear (1) using J 24420-B Puller (2)
the measurements. or similar tool (figure 10-28).
- Main bearing journal diameter 58.37 58.40 B. Remove key from crankshaft.
mm (2.2979 - 2.2994 in.)
C. Install keyway on crankshaft.
- Maximum taper 0.025 mm (0.0010 in.)
D. Install new gear (1) on crankshaft, making
- Maximum out-of-round 0.025 mm (0.0010 sure the timing mark is away from the crank-
in.) shaft. Push gear tight against shoulder
using J 5590 Installer (3).
IMPORTANT: If the journal diameter is less than
specification, replace crankshaft or have jour-
nals ground undersize by a qualified machine
shop.
Install or Connect
1. Install main bearing caps and bolts on block.
Tighten
• Main bearing bolts to 88 N•m (65 lb. ft.)
Measure
• Measure main bearing diameters (figure 10-
27). Subtract main bearing journal diameter
(from Step 1) from main bearing diameter to
get the main bearing clearance. Compare
results with specifications given in this chapter
under Measure Main Bearing Clearance.

131-113

Figure 10-27 Measuring Main Bearing Diameter

IMPORTANT: If bearing clearance exceeds 131-094

specifications, replace bearing inserts and
Figure 10-28 Crankshaft Gear Removal and
crankshaft or grind crankshaft main bearing
Installation
journals and install undersize bearing inserts.

10-16 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

CONNECTING ROD SIDE PLAY AND

CAUTION
BEARING CLEARANCE
MEASUREMENT DO NOT touch the bearing surface of the bearing
insert with your fingers. Oil and acid from the skin
Figures 10-29 through 10-31
can etch the bearing surface.
Measure
• Connecting rod side clearance using a feeler A. Remove connecting rod cap and wipe all oil
gauge between the connecting rod and crank- from bearing insert and crankshaft journal.
shaft (figure 10-29). If side play exceeds spec- B. Put a piece of gauging plastic across the
ification, replace connecting rod and connect- entire width of the bearing insert (figure 10-
ing cap. 30).
- Connecting rod side clearance 0.15 0.43
mm (0.006 - 0.017 in.) CAUTION
DO NOT rotate the crankshaft. This will distort
the gauging plastic.

C. Install connecting rod cap with gauging

plastic in position. Tap cap into place with a
soft faced hammer. Tighten connecting rod
cap nuts.
Tighten
• Connecting rod cap nuts to 60 N•m (45 lb.
ft.)
600-259

Figure 10-29 Measuring Connecting Rod Side D. Remove nuts and connecting rod cap.
Clearance Gauging plastic will adhere to either the
bearing cap or journal.
E. Measure the flattened gauging plastic at its
NOTICE: Connecting rod bearing clearance can be widest point with the scale printed on the
measured two ways. The Plastigage method is gauging plastic package (figure 10-31).
used here. Direct measurement can be made after Remove all gauge material.
the pistons have been removed.
F. If clearance exceeds specification, replace
• Connecting rod bearing clearance for each bearing inserts.
piston.

CAUTION
Each connecting rod and cap must be kept
together as a set. Check the connecting rod and
cap for identification marks; mark the parts if
necessary, so parts can be installed in the same
position as removed.

600-175

Figure 10-30 Placement of Plastigage

IES 131 8/99 10-17

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS

131-114

Figure 10-32 Connecting Rod Journal Diameter

Install or Connect
600-176
1. Connecting rod cap and nuts on connecting
Figure 10-31 Measuring Plastigage rod.
Measure Tighten
• Connecting rod bearing clearance 0.076 mm • Connecting rod cap nuts to 60 N•m (45 lb. ft.)
(0.0030 in.) maximum Measure
If clearance is correct, apply clean engine oil to • Connecting rod bearing diameter (figure 10-
bearing surface of insert. Install connecting rod cap 33). Subtract connecting rod journal diameter
and nuts. (from step 1) from connecting rod bearing
Tighten diameter to get the connecting rod bearing
clearance.
• Connecting rod cap nuts to 60 N•m (45 lb. ft.)
- Connecting rod bearing clearance 0.076
CONNECTING ROD AND PISTON mm (0.0030 in.) maximum
INSPECTION
Figures 10-32 through 10-39
Tool Required:
J 9510 Piston Support Tool
J 24086-B Piston Pin Remover and Installer
Measure
• Measure each connecting rod journal diameter
(1) in several places, approximately 90° apart
using a micrometer (figure 10-32). Check also
for tapered or out-of-round journals. Calculate
131-115
the average of the measurements.
- Connecting rod journal diameter - 53.28 - Figure 10-33 Measuring Connecting Rod Bearing
53.33 mm (2.0980 - 2.0995 in.) Diameter
- Maximum taper - 0.025 mm (0.0010 in.)
- Maximum out-of-round - 0.025 mm (0.0010 in.) IMPORTANT: If bearing clearance exceeds
specification, replace bearing inserts and
IMPORTANT: If any connecting rod journal crankshaft or grind crankshaft connecting rod
diameters are less than specification, replace journals and install undersize bearing inserts.
crankshaft or have journals ground undersize
by a qualified machine shop. If journals are
ground, undersize bearing inserts must be
installed.

10-18 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

NOTICE: New piston rings should also be checked

using the following procedures.
Measure
• Measure piston ring groove clearance (figure
10-34). Measure several places around piston.
- Maximum ring groove clearance:
- Top and second rings - 0.099 mm (0.0039
in.)
- Bottom (oil) ring - 0.178 mm (0.007 in.)

600-166

Figure 10-35 Measuring Piston Ring Gap

IMPORTANT: If gap exceeds specification,

replace the rings.

CAUTION
600-168

Figure 10-34 Measuring Piston Ring Groove If bosses on pistons DO NOT allow the J 9510
Clearance piston support tool to seat squarely on the piston,
grind or turn the upper end of the tool to dimen-
sions shown (figure 10-36).
IMPORTANT: If clearance exceeds specifica-
tions, replace piston or rings.
Remove or Disconnect
1. Three piston rings from each piston, using a
piston ring expander.
2. Use the piston to push the ring squarely into
the cylinder bore at the bottom of the ring trav-
el.
3. Remove the piston and measure the piston
ring gap using a feeler gauge (figure 10-35).
4. Follow steps 2 and 3 for each ring in its appro- 131-116

priate cylinder. Figure 10-36 Piston Support Tool J 9510

Measure
• Maximum ring gap clearance: Remove or Disconnect
- Top ring - 0.76 mm (0.030 in.) 1. Remove piston pin using a press and J 9510
- Second ring - 0.89 mm (0.035 in.) Piston Support Tool (figure 10-37). The spring
and pilot for the support tool are not used for
- Bottom (oil) ring -1.02 mm (0.040 in.)
removal.

IES 131 8/99 10-19

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS
Example:
mm (in.)
Piston Pin Bore 23.564 (0.9277)
Piston Pin Dia. 23.546 (0.9270)
Clearance 0.018 (0.0007)
If the clearance exceeds specification, both piston
and pin must be replaced.
Measure
• Piston pin clearance 0.025 mm (0.0010 in.)
3. Pistons:
A. Clean pistons in cleaning solvent and dry
with compressed air. DO NOT use a wire
brush on any part of the piston.
B. Clean the ring grooves with a ring groove
cleaner or the end of a piston ring filed to a
sharp point. Make sure oil ring holes and
600-159
slots are clean. Check grooves for nicks or
burrs that may cause rings to bind or seize.
Figure 10-37 Pressing Out Piston Pin
C. Inspect piston for cracks at ring lands, skirts
and pin bores. Inspect piston for scuffing or
Inspect scoring; replace as necessary.
1. Connecting rods (figure 10-38):
D. Measure piston skirt diameter approximate-
A. Clean connecting rods in cleaning solvent ly 64 mm (2.5 in.) down from the top of the
and dry with compressed air. piston and perpendicular to the piston pin
B. Check rod for twists, bends, nicks or cracks; bore (figure 10-39). Measure cylinder bore
replace connecting rods that are damaged. approximately 57 mm (2.25 in.) down from
the top of the bore. Subtract piston diameter
from the bore diameter to get the piston
clearance.

Example:
mm (in.)
Cylinder Bore 101.638 (4.0015)
Piston Diameter. 101.562 (3.9985)
Clearance 0.076 (0.0030)
131-118

Figure 10-38 Piston and Connecting Rod

2. Piston pins:
A. Piston pin bore and piston pin must be free
of varnish or scuffing:
B. Measure the piston pin bore and the piston
pin. Subtract piston pin diameter from the
bore diameter to get the piston pin clear-
ance.

10-20 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

131-119

Figure 10-39 Piston Skirt Measurement Location

Measure
• Piston Clearance 0.114 mm (0.0045 in.)
maximum

ASSEMBLE CONNECTING ROD AND

PISTON
Figures 10-40 and 10-41
1. Apply clean engine oil to piston pin hole and
connecting rod pin bore.

CAUTION
Connecting rod bearing tangs must always be 131-120

opposite of the camshaft side of the cylinder Figure 10-40 Assembling Piston and Connecting
block. Rod

2. Put piston (4) on connecting rod (3) keeping in

mind the connecting rod tangs (A) must be 6. Install piston rings (1-4) as follows (figure 10-
toward the rear of the cylinder block and the 41):
notch (B) in top of piston on the same side as
A. If new piston rings are used, put each ring
the tangs.
into the cylinder in which it is going to be
3. Put J 9510 Piston Support Tool with spring (6) used to check ring gap (see procedure in
and pilot (5) on press (figure 10-40). Put piston this chapter under Inspect Connecting Rod
and connecting rod on support (7) with the pilot and Piston).
through the piston and rod.
B. Install oil ring spacer (4) in groove and put
4. Install piston pin (2) using pusher (1) and anti-rotation tang in oil hole. Locate ends of
press. Push pin into piston until pilot bottoms in spacer at position 4.
support.
C. Hold spacer ring ends together and install
5. Remove piston and connecting rod assembly lower steel oil ring rail (3) with the gap locat-
from press. Check piston for freedom of move- ed at position 3A.
ment on piston pin.
D. Install upper steel oil ring with gap at posi-
tion 3B.

IES 131 8/99 10-21

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS
E. Flex the oil ring assembly to make sure ring MEASURE MAIN BEARING
is free. If binding occurs at any point, the
CLEARANCE
cause should be determined; if caused by
the ring groove, remove by dressing the Figures 10-42 through 10-44
groove with a fine file. If binding is caused
by a distorted ring, try a new ring. NOTICE: Main bearing clearance can be
F. Install second compression ring (2) using a measured two ways. The Plastigage method is
piston ring expander. Make sure the marked used here. Direct measurement can be made after
side of compression ring is toward the top of the crankshaft has been removed.
the piston and move ring gap to position 2.
G. Install top compression ring (1) with the CAUTION
marked side toward the top of the piston.
Put the ring gap at position 1. The main bearing cap must be installed in its
H. When new rings are installed, check ring original position. Check the main bearing caps for
groove clearance. location marks; mark the caps if necessary, so
caps can be installed in the same position as
7. If a new connecting rod has been installed, removed.
mark connecting rod and cap with the cylinder
number in which it will be installed. The mark
should be made on the side of rod and cap CAUTION
with slots for connecting rod bearing tabs.
DO NOT touch the bearing surface of the bearing
insert with your fingers. Oil and acid from the skin
can etch the bearing surface.

1. Measure the main bearing clearance using the

following procedure:
A. Put engine upside-down and remove rear
main bearing cap first. Wipe oil from bearing
insert and crankshaft journal.
B. Put a piece of gauging plastic across the full
width of bearing journal, parallel to the
crankshaft (figure 10-42).

131-121

Figure 10-41 Piston Ring Placement

600-175

Figure 10-42 Placement of Plastigage

10-22 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

Tighten
CAUTION • Main bearing bolts to 88 N•m (65 lb. ft.)
DO NOT rotate the crankshaft. This will distort F. Repeat Steps A-E for each main bearing.
the gauging plastic.
NOTICE: Rear main bearing also serves as thrust
C. Install bearing cap and tighten the bolts bearing.
evenly to specifications. 2. Measure crankshaft end play using the follow-
Tighten ing procedure:
• Main bearing bolts to 88 N•m (65 lb. ft.) A. Force the crankshaft forward.
D. Remove bolts and main bearing cap. Gaug- B. Measure the clearance between the front of
ing plastic will adhere to either the bearing the rear main bearing and the crankshaft
cap or journal. using a feeler gauge (figure 10-44)
E. Measure the flattened gauging plastic at its Measure
widest point with the scale printed on the • Crankshaft end play 0.05 - 0.15 mm (0.002 -
gauging plastic package (figure 10-43). 0.006 in.)
Remove all gauge material.
IMPORTANT: If crankshaft exceeds specifica-
tion, remove crankshaft and inspect rear main
bearing and crankshaft for wear.

600-176

Figure 10-43 Measuring Plastigage

131-122

Measure Figure 10-44 Measuring Main Bearing Side

• Main bearing clearance: Clearance
- First four bearings 0.025-0.0635 mm
(0.0010-0.0025 in.) CAMSHAFT INSPECTION
- Rear bearing 0.038-0.089 mm
Figure 10-45 through 10-48
(0.0015 - 0.0035 in.)
Inspect
IMPORTANT: If clearance exceeds specifica-
• Camshaft journals and lobes for wear, scoring
tion, replace bearing inserts. If clearance is
or damage; inspect gear teeth for damage.
correct, apply clean engine oil to bearing
surface of bolts. Measure
1. Check the camshaft bearing journal diameters
using a micrometer (figure 10-45).
- Camshaft journals diameter range:
47.44 - 47.49 mm (1.8677 - 1.8697 in.)

IES 131 8/99 10-23

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS
2. Check the bearing journals for runout (align-
ment) using V-blocks and a dial indicator
(figure 10-46).
- Camshaft maximum runout 0.038 mm
(0.0015 in.)

131-123

Figure 10-47 Measuring Thrust Plate Clearance

A. Put camshaft in press (figure 10-48). Use a
sleeve or pipe (1) to support gear at the hub.
B. Push camshaft from gear, using care not to
600-217 lose key, thrust plate and gear spacer ring.
Figure 10-45 Measuring Camshaft Bearing C. Support camshaft behind the front bearing
Journals journal in a press.
D. Put gear spacer ring, thrust plate and key on
camshaft.
E. Push gear onto shaft tight against spacer
ring.
F. Check thrust plate clearance.

600-216

Figure 10-46 Checking Camshaft Journal Runout

3. Inspect camshaft gear and thrust plate for

wear or damage. Measure clearance between
thrust plate and front journal of camshaft using
a feeler gauge (figure 10-47).
- Camshaft-to-thrust plate clearance 0.08 -
0.20 mm (0.003 - 0.008 in.)

IMPORTANT: If camshaft does not fit the speci-

fications, replace camshaft thrust plate, or gear,
(using the following procedures) and inspect
bearings. 131-124

Figure 10-48 Pressing Off Camshaft Gear

CAUTION
Move thrust plate so woodruff key does not
damage thrust plate when the shaft is pushed
from the gear.

10-24 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

CAMSHAFT BEARING REMOVAL 6. Remove camshaft bearing by holding puller

screw with one wrench and turning puller nut
Figure 10-49 and 10-50 with another wrench. Remove puller when the
Tools Required: bearing is pulled from bore.
J 6098 Camshaft Bearing Remover and 7. Remove the front and rear camshaft bearings
Installer by installing puller disk on a driver handle and
pushing the bearings towards the center of the
NOTICE: To replace camshaft bearings without cylinder block (figure 10-50).
complete disassembly, remove camshaft and
crankshaft but leave cylinder head and pistons in
position.
Remove or Disconnect
1. Before removing crankshaft, cover or tape
threads of connecting rod bolts to protect bear-
ing surfaces of crankshaft.
2. Fasten the connecting rods to the sides of the
engine block so they will not be in the way of
camshaft bearing removal.
131-126
3. Remove camshaft plug at the rear of the
engine block. Figure 10-50 Removing Front and Rear Camshaft
Bearings
4. Install pilot bushing (2) from J 6098 Camshaft
Bearing Remover and Installer, in front
camshaft bearing (figure 10-49). Install puller
screw (3), with puller nut (5) and washer (4)
INTAKE/EXHAUST MANIFOLD
moved to the head of the puller screw, through INSPECTION
the pilot bushing. Inspect
5. Install puller disk (1) into inner camshaft bear- 1. Remove all gasket material from machined
ing with shoulder against bearing. Make sure surfaces. Do not allow sealing material to fall
puller disk engages a sufficient number of into engine block.
threads of the puller screw.
2. Inspect all machined surfaces for marks or
deep scratches that may cause leaks. Look for
any cracks in the manifold.
3. Make sure all passages are free of any mater-
ial build-up or corrosion.

NOTICE: If pipe plugs are removed from exhaust

manifold, apply Locktite® Pipe Sealant with Teflon
to threads of plugs before installation.

131-125

Figure 10-49 Removing Inner Camshaft Bearings

IES 131 8/99 10-25

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS
4. Test manifold for leaks by installing plugs and
block-off plates with new gaskets on manifold.
One opening must have an access for
connecting an air hose. Apply approximately
172 kPa (25 psi) of air pressure with the mani-
fold under water. Bubbles will indicate any
leakage.

ROCKER ARM AND PUSHROD

INSPECTION
Figure 10-51
Inspect
1. Inspect rocker arm and ball mating surfaces.
These surfaces must be smooth and free from
600-228
scoring and other damage. Replace parts as
necessary. Figure 10-52 Removing Rocker Arm Stud
2. Rocker arm areas that contact the valve stems
and pushrods must be smooth and free from CAUTION
wear or damage. If rocker arm is worn or
damaged, check pushrod ends and valve stem DO NOT attempt to install an oversize rocker arm
also. Replace all worn or damaged parts. stud without reaming the stud hole. Cylinder
3. Inspect pushrods for bent condition by rolling head could be damaged or cracked.
on a flat surface. Replace pushrod if it is bent.
3. Ream the stud hole to the proper size for the
replacement oversize rocker arm stud (figure
10-53). Use J 5715 Reamer for 0.08 mm
(0.003 in.) oversize stud; J 6036 Reamer for
0.33 mm (0.013 in.) oversize stud.

131-101

Figure 10-51 Rocker Arm and Pushrod

ROCKER ARM STUD

REPLACEMENT
Figures 10-52 through 10-54
Tools Required:
J 5802-01 Rocker Arm Stud Remover
J 6880 Rocker Arm Stud Installer
1. Put J 5802-01 Rocker Arm Stud Remover, flat
washer and nut over stud (figure 10-52).
131-154
2. Turn nut until stud is free of cylinder head.
Figure 10-53 Reaming Rocker Arm Stud Hole

10-26 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

4. Apply hypoid axle lubricant to the force fit area Clean

of the rocker arm stud. 1. Carbon from combustion chambers and valve
5. Install the rocker arm stud using J 6880 Rock- ports using J 8089 Wire Brush Tool (figure 10-
er Arm Stud Installer (figure 10-54). When the 57).
tool bottoms against the cylinder head, the
stud is installed to the correct depth.

600-225

Figure 10-55 Compressing Valve Springs

600-230

Figure 10-54 Installing Rocker Arm Stud

DISASSEMBLE CYLINDER HEAD

Figures 10-55 and 10-56
Tool Required:
J 8062 Valve Spring Compressor

131-127
CAUTION
Figure 10-56 Valve Components
Keep all components of each valve together as a
set. Place components in a rack so they can be
installed in the same position from which they
were removed.

1. Compress valve springs with J 8062 Spring

Compression Tool to remove valve keepers (2)
(figure 10-55).
2. Remove compression tool to remove valve (6
or 7), cap (2), shield (3), seal (4), and spring
(5) (figure 10-56). Place parts in a rack for
installation in their original position.

CYLINDER HEAD CLEANING

Figures 10-57 and 10-58
600-231
Tool Required:
J 8089 Wire Brush Figure 10-57 Cleaning Cylinder Head
J 8101 Valve Guide Cleaning Tool

IES 131 8/99 10-27

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS
2. Valve guide bores using J 8101 Valve Guide
Cleaning Tool (figure 10-58). CAUTION
3. Remove carbon from valves using a soft wire
Excessive valve stem-to guide clearance can
buffing wheel.
cause excessive oil consumption and may cause
4. Remove gasket material from engine block valve to break. Insufficient clearance will result in
and cylinder head mating surfaces. Use care noisy and sticky operation of the valve and cause
not to scratch or damage mating surfaces. the engine to run rough.

Measure
1. Stem clearance as follows:
A. Install valve in cylinder head in the valve
guide from which it was removed.
B. Clamp a dial indicator (J 8520 or equivalent)
on one side of the cylinder head rocker arm
cover gasket rail.
C. Locate the indicator so movement of the
valve stem from side-to-side (crosswise to
the cylinder head) will cause a direct move-
ment to the indicator stem. The indicator
stem must contact the side of the valve
stem just above the valve guide.
D. Move the valve head approximately 1.6 mm
(0.06 in.) off the valve seat.
E. Move the stem of the valve from side to-side
using light pressure to obtain a clearance
reading (figure 10-59).
600-232 - Intake Valve 0.094 mm (0.0037 in.)
Figure 10-58 Cleaning Valve Guides - Exhaust Valve 0.119 mm (0.0047 in.)

CYLINDER HEAD INSPECTION

Figures 10-59 and 10-60
Tool Required:
J 8520 Dial Indicator (or equivalent)
Inspect
1. Cylinder head for cracks in the exhaust ports,
combustion chambers and external cracks to
the water chamber. Replace cylinder head if
cracks are found.
2. Cylinder head for flatness using an accurate
straightedge and feeler gauge. Over the entire
length of the head, the maximum allowable
clearance between the straightedge and head
is 0.15 mm (0.006 in.).
3. Valves for burned heads, cracked faces or
damaged stems; replace valve as necessary. 600-234

Figure 10-59 Measuring Valve Stem Clearance

10-28 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

NOTICE: If clearance exceeds the specifications,

valve guides must be reamed to fit new oversized
valves. Refer to Cylinder Head Reconditioning.
2. Valve spring compression using J 8056 Spring
Tester (figure 10-60). Compress springs to the
specified height and check spring force.
- Free length - 52.3 mm (2.06 in.)
- Test force at 40.9 mm - 445-489 N (1.61 in.
- 100 - 110 lb.)
- Test force at 31.0 mm - 925-988 N (1.22 in.
- 208 - 222 lb.)

NOTICE: Replace spring if it is not within 44 N (10

lb.) of specification.

600-236

Figure 10-61 Reaming Valve Guides

NOTICE: Several different types of equipment are

available for conditioning valve seats. The recom-
mendations of the equipment manufacturer must be
carefully followed to attain proper results.
Measure
• Valve seat angle, width and concentricity
(figure 10-62):
- Angle - 46°
600-235
- Width:
Figure 10-60 Checking Valve Spring Compression
Intake - 1.27 - 1.78 mm (0.050 - 0.070
in.)
Inspect
Exhaust - 1.52 - 2.02 mm (0.060 - 0.080
• Rocker arm studs for wear or damage; replace
in.)
as necessary.
- Runout - 0.05 mm (0.002 in.) max.
CYLINDER HEAD RECONDITIONING 3. Recondition valves.
Figures 10-61 through 10-63
Tool Required:
J 5830 Reamer Set
1. Ream valve guide bores.
A. Use J 5830 Reamer Set to ream valve guide
bores for oversize valves (figure 10-61).
B. Remove sharp edge (made by reamer) at
top of valve guide.
2. Recondition valve seats. Reconditioning the
valve seats is very important because the
seating of the valves must be perfect for the
engine to deliver the power and performance
designed into it. 600-237

Figure 10-62 Valve and Seat Angles

IES 131 8/99 10-29

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS
NOTICE: Several different types of equipment are ASSEMBLE CYLINDER HEAD
available for refacing valves. The recommendations
of the equipment manufacturer must be carefully Figures 10-64 through 10-67
followed to attain proper results. Tools Required:
A. Grind valve face as necessary. If edge of J 8062 Valve Spring Compressor
valve head is less than 0.8 mm (0.031 in. ), J 23738-A Vacuum Pump
replace valve. 1. Apply engine oil to valve guides and valve
stems. Install each valve (6 or 7) into the same
CAUTION guide from which it came or to which it was
fitted (figure 10-64).
DO NOT grind end of stem excessively. Only 2. Install spring (5), shield (3) and cap (2).
extreme end of valve stem is hardened to resist
3. Apply engine oil to seal (4) and grease to
wear.
keepers (1).
B. Remove any pit or scoring on rocker arm 4. Compress valve spring using J 8062 Spring
end of valve stem by grinding squarely Compressor Tool (figure 10-65).
(figure 10-63). 5. Install seal (3) and keepers (2) on valve stem.
Measure Make sure seal is not twisted.
• Valve dimensions:
- Angle - 45°
- Edge thickness 0.8 mm (0.031 in.) min.

131-127

Figure 10-64 Valves and Components

131-095

Figure 10-63 Valve Stem End Wear

4. Check valve seating:

A. Clean valve face and seal of all grinding
particles.
B. Put pencil marks across valve face approxi-
mately every 6 mm (0.250 in.).
C. Install valve in proper position of cylinder
head. Apply firm pressure on valve and 600-225
make 1/2 turn in each direction. Figure 10-65 Compressing Valve Springs
D. Remove valve and inspect valve face. If all
pencil marks have not been removed at
point of contact, repeat reconditioning of
valves and valve seats.

10-30 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

6. Carefully release spring pressure, making sure NOTICE: If this height is exceeded, install a valve
valve keepers stay in place. Remove spring spring seat shim approximately 1.60 mm (0.0625
compressor. in.) thick. Never shim spring to a height less than
7. Check each seal for leakage: specification.
A. Install suction cup of J 23738-A Vacuum
DISASSEMBLE HYDRAULIC LIFTER
Pump over the valve shield (figure 10-66).
B. Create a vacuum and watch the needle of Figure 10-68
the vacuum gauge. Needle should not The internal components of each hydraulic lifter is
move. a matched set. DO NOT mix components. Replace
C. If needle moves, seal is damaged or complete lifter if any internal wear or damage is
installed wrong causing a leak; replace seal. noted.
Measure 1. Using a pushrod, push pushrod seat (3) into
• Installed height of the valve springs, using a lifter body (2) and hold to remove retainer (1)
narrow thin scale or cutaway scale. Measure (figure 10-68).
from the spring seat to the top of the valve
spring (figure 10-67).
- Valve spring installed height:
41.9 +/- 0.8 mm (1.65 +/- 0.03 in.)

131-129

600-240
Figure 10-68 Cutaway of Lifter
Figure 10-66 Checking Valve Stem Seals
2. Remove pushrod seat, metering valve (4),
plunger and ball check assembly, and plunger
spring (6).
3. Remove ball check (9) and spring (8) by prying
ball check retainer (7) from the plunger (5).
4. Thoroughly clean all parts in cleaning solvent.
Inspect parts for wear or damage; replace
complete lifter if any part is worn.

600-242

Figure 10-67 Measure Valve Spring Installed

Height

IES 131 8/99 10-31

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS

ASSEMBLE HYDRAULIC LIFTER 6. Remove the 3 mm (0.125 in.) punch and fill
lifter with oil again.
Figures 10-69 and 10-70
7. Install metering valve, pushrod seat and retain-
1. Put ball check on small hole of plunger. er.
2. Install ball check spring in ball check retainer 8. Push pushrod seat down to remove the 1.5
(1) and put retainer over ball so spring is mm (0.625 in.) punch. Relieve pressure on the
against ball (figure 10-69). Push retainer into pushrod seat gradually.
plunger (2) using a small screwdriver.
3. Put plunger spring over check ball retainer. DISASSEMBLE OIL PUMP
Slide lifter body over spring and plunger while Figure 10-71
using care to align oil holes in plunger and lifter
body. 1. Remove pump cover screws (6), cover (7) and
gasket (8).
4. Turn lifter body over and fill with clean 10/W
(SG or SH) oil. 2. Mark gear teeth so gears may be assembled
with the same gears meshing together, main-
5. Push plunger down using a 3 mm (0.125 in.)
taining the same wear pattern.
punch (1) to align oil holes (2) (figure 10-70).
Install a 1.5mm (0.0625 in.) punch (3) through 3. Remove idler gear (9) and drive gear (10) from
both oil holes to hold plunger down. pump body (1).
4. Remove pressure regulator retaining pin (5),
spring (4) and valve (3).

NOTICE: DO NOT remove pickup screen and pipe

assembly unless replacement is necessary. A
loose fit between pickup pipe and pump body can
cause an air leak, reducing oil pressure.
5. If necessary, remove pickup screen and pipe
assembly (2) by putting pump body in a soft
jaw vise and pull pipe from vise.

131-130

Figure 10-69 Assembly of Lifter (step A)

131-132

Figure 10-71 Oil Pump Disassembly

131-131

Figure 10-70 Assembly of Lifter (step B)

10-32 IES 131 8/99

3.0L Cleaning, Inspection, and Repair

OIL PUMP INSPECTION Tighten

• Oil Pump Cover Screws to 7 N•m (60 lb. in.).
1. Wash all parts in cleaning solvent and dry with
compressed air. 5. Check pump for smooth operation by rotating
drive shaft by hand.
NOTICE: DO NOT remove pickup screen and pipe
assembly unless replacement is necessary. A IMPORTANT: Avoid twisting, shearing or
loose fit between pickup pipe and pump body can collapsing pipe when installing pickup assem-
cause an air leak, reducing oil pressure. bly in the pump. Pickup screen must be parallel
to oil pan rails when pump is installed.
2. Inspect the pump body and cover for cracks or
excessive wear. Check the inside of the pump 6. If pickup pipe and screen assembly was
cover and body for wear that would allow oil to removed, apply sealer to end of pipe and use
leak past the sides of the gears. J 8369 Suction Pipe Installing Tool to install
assembly (figure 10-72).
3. Inspect the pump gears for wear or damaged
teeth.
4. Check the drive gear shaft for looseness in the
pump body.
5. Inspect the pickup screen and pipe assembly
for damage to screen or pipe or loose fit in
pump body.
6. Check pressure regulator valve fit.

ASSEMBLE OIL PUMP

Figures 10-71 and 10-72
Tool Required:
J 8369 Suction Pipe Installing Tool
1. Apply clean engine oil to all internal parts of oil
pump.
2. Install pressure regulating valve (3), spring (4)
and retaining pin (5) (figure 10-71).
3. Install drive gear (10) and idler gear (9) in the 131-133

pump body (1), aligning marks made during Figure 10-72 Using Suction Pipe Installing Tool
disassembly.
4. Install gasket (8), cover (7) and screws (6).

IES 131 8/99 10-33

Cleaning, Inspection, and Repair INDUSTRIAL ENGINE SYSTEMS

THIS PAGE WAS INTENTIONALLY LEFT BLANK

10-34 IES 131 8/99

3.0L Assembly of Engine

ASSEMBLY OF ENGINE
English and Metric Fasteners 6. Lightly tap the end of the crankshaft first rear-
ward and then forward using a soft faced
hammer (figure 10-74). This will align the rear
CAUTION main bearing and crankshaft thrust surfaces.
Late model engines use a combination of English 7. Tighten rear bearing cap bolts.
and Metric threaded fasteners. The components
effected are starter motor, engine mounts, and
flywheel housing mounting. Verify that the prop-
er fasteners are used whenever removing or
replacing one of these components.

PRIOR TO ASSEMBLY
The importance of cleanliness during assembly
procedure cannot be over stressed. Dirt will cause
premature wear of the rebuilt engine.
Lubricate all moving parts lightly with engine oil or
engine assembly lubricant (unless specified other-
wise) during assembly. This will provide initial lubri-
cation when the engine is started.

CRANKSHAFT INSTALLATION
Figures 10-73 and 10-74
Install or Connect

CAUTION
Make sure that the cylinder block, crankshaft 131-134

journals and bearings are clean. Figure 10-73 Installing Bearing Caps
1. Install main bearing inserts in cylinder block
and bearing caps.
2. Apply a thin layer of clean engine oil on bear-
ing surfaces.

IMPORTANT: Carefully install crankshaft into

cylinder block not to damage bearing surfaces.
3. Install all bearing caps (1) and bolts except the
rear bearing cap (2) (figure 10-73). Make sure
131-135
indicating arrows on the bearing caps point
towards the front of the engine. Figure 10-74 Tapping Crankshaft to Align Main
Tighten Bearing
• Main bearing cap bolts to 88 N•m (65 lb. ft.) Tighten
5. Install rear bearing cap bolts with indicating • Main bearing bolts to 88 N•m (65 lb. ft.)
arrow (3) pointing towards the front of the 8. Check crankshaft end play (see procedure in
engine. Tighten bolts initially to 14 N•m (10 lb. this chapter).
ft.).

IES 131 8/99 10-35

Assembly of Engine INDUSTRIAL ENGINE SYSTEMS

CAMSHAFT BEARING
INSTALLATION
Figure 10-75 and 10-76
Clean
• Camshaft bearing bores in the cylinder block
with solvent and dry with compressed air. Be
sure the grooves and oil passages are clean.
Install or Connect

CAUTION
Make sure oil hole in camshaft bearing is aligned
with oil hole in cylinder block for proper engine
lubrication.
131-125

1. Put front and rear camshaft bearings in posi- Figure 10-76 Installing Inner Camshaft Bearings
tion. Make sure oil hole in bearing is aligned
with oil hole in cylinder block.
3. Install pilot bushing (2) from J 6098 Camshaft
NOTICE: Front bearing must be pushed approxi- Bearing Remover and Installer in front
mately 3 mm (0.12 in.) below front surface of cylin- camshaft bearing (figure 10-76). Install puller
der block to uncover oil hole in bore. screw (3), with puller nut (5) and washer (4)
moved to the head of the puller screw, through
2. Install the front and rear camshaft bearings by the pilot bushing.
installing puller disk on a driver handle and
pushing the bearings towards center of cylin- 4. Align new inner bearing oil holes and install
der block (figure 10-75). Check oil hole posi- puller disk (1) with shoulder against bearing.
tion. 5. Install intermediate bearing by holding puller
screw with one wrench and turning puller nut
with another wrench. Remove puller when the
CAUTION
bearing is pulled into bore. Check oil hole
alignment.
Do not nick or damage front camshaft bearing
when using installation tool. 6. Apply Sealing Compound (GM part no.
1052080) or equivalent to new camshaft rear
plug. Install a camshaft plug. Plug must be
flush to 0.8 mm (0.03125 in.) deep and paral-
lel to surface of cylinder block.

131-126

Figure 10-75 Installing Front and Rear Camshaft

Bearings

10-36 IES 131 8/99

3.0L Assembly of Engine

CAMSHAFT INSTALLATION Tighten

• Camshaft thrust plate bolts to 9 N•m (80 lb.
Figures 10-77 and 10-78 in.)
Install or Connect 5. Check camshaft gear and crankshaft gear
1. Apply moly lube to camshaft lobes and jour- runout using a dial indicator (figure 10-78).
nals.
IMPORTANT: If gears are not within specifica-
2. Carefully install camshaft in engine so not to
tion, remove gear. Clean and remove burrs from
damage camshaft bearings or camshaft.
shaft before installing gear. If gear is still not
3. Align timing marks (1) as camshaft gear and within specification, replace gear.
crankshaft gear engage (figure 10-77).
Measure
4. Install and tighten thrust plate bolts (2).
• Camshaft gear runout:
0.10 mm (0.004 in.) maximum
Crankshaft gear runout:
0.08 mm (0.003 in.) maximum
6. Check timing gears backlash using a dial indi-
cator. Backlash must be within specification; if
not, replace gears.
Measure
• Timing gears backlash:
- New parts - 0.10 - 0.15 mm (0.004 -
0.006 in.)
- Used parts - 0.20 mm (0.008 in.) maxi-
131-110
mum
Figure 10-77 Aligning Timing Gear Marks
CAUTION
If a new camshaft is installed, replace all
hydraulic lifters, change engine oil and filter, and
apply moly lube to bottom of lifters.

CONNECTING ROD AND PISTON

INSTALLATION
Figures 10-79 through 10-82
Tool Required:
J 5239 Rod Guide Set
J 8037 Ring Compressor
Install or Connect

CAUTION
It is important that a good cleaning operation is
performed (figure 10-79). Any material remaining
in the bore will cause premature engine wear in
131-136 cylinders and bearings.
Figure 10-78 Checking Timing Gear Runout

IES 131 8/99 10-37

Assembly of Engine INDUSTRIAL ENGINE SYSTEMS

131-138
131-137
Figure 10-81 Piston Ring Alignment
Figure 10-79 Cleaning Cylinder Bore

1. Install connecting rod bearings in rods and CAUTION

caps. Apply a light layer of engine oil to bear-
ings. Be sure piston ring gaps are in the proper posi-
2. Install J 5239 Rod Guide Set on connecting tion before installing ring compressor on piston.
rod studs (figure 10-80).
4. Install J 8037 Ring Compressor on piston with-
3. Apply a thin layer of clean engine oil on piston out changing the position of the ring gaps.
and rings.
5. Install the piston and connecting rod in its
4. Align piston rings (figure 10-81) to the follow- respective bore with the notch in the top of the
ing positions: piston towards the front of the engine and the
A. Top compression ring and gap location (1). connecting rod bearing tang slots towards the
B. Second compression ring and gap location outside of the engine.
(2).
C. Oil ring rails and gap locations A and B (3).
D. Oil ring spacer and ends location (4).
E. Piston Notch (5).

600-257

Figure 10-82 Tapping Piston Into Cylinder

600-208

Figure 10-80 Using Rod Guide Set

10-38 IES 131 8/99

3.0L Assembly of Engine

6. Guide the connecting rod to the connecting rod

journal with tool J 5239 and use light blows
with a hammer handle to tap piston into its
bore (figure 10-82). Hold the ring compressor
squarely against the block until all the rings
have entered the bore.

NOTICE: Each connecting rod and bearing cap

should be marked, beginning at the front of the
engine. The number on the connecting rod and the
bearing cap must be on the same side if the rod is
ever transposed from one block or cylinder to
another; new connecting rod bearings should be
fitted and the connecting rod should be numbered
to correspond with the new cylinder number.
8. Install connecting rod cap (1) with bearing and 131-106

nuts (2) (figure 10-83). Figure 10-84 Oil Pump

Tighten
• Connecting rod cap nuts to 60 N•m (45 lb. REAR CRANKSHAFT OIL SEAL
ft.) INSTALLATION
Figure 10-85
Install or Connect
1. If removed, install oil seal retainer stud.
Tighten
• Oil seal retainer stud to 1.7 N•m (15 lb. in.)
2. Clean gasket surfaces of engine block and
seal retainer.
3. Install gasket on engine block. Do not use
sealant (figure 10-85).
4. Install seal retainer and nuts.

131-109
Tighten
Figure 10-83 Connecting Rod Cap and Nuts • Seal retainer nuts to 15.3 N•m (135 lb. in.)

OIL PUMP INSTALLATION

Figure 10-84
Install or Connect
1. Oil pump and extension shaft. Align the slot in
the extension shaft with the tang on the distrib-
utor shaft. Oil pump must slide easily into posi-
tion. Turn pump shaft as necessary.
2. Oil pickup tube bolt (1).
3. Oil pump-to-crankcase bolts (2).
Tighten
• Oil pump-to-crankcase bolt to 14 N•m (120 600-210
lb. in.)
Figure 10-85 Rear Crankshaft Oil Seal Retainer

IES 131 8/99 10-39

Assembly of Engine INDUSTRIAL ENGINE SYSTEMS

OIL PAN INSTALLATION REAR CRANKSHAFT OIL SEAL

Figure 10-86 RETAINER INSTALLATION
1. Make sure gasket surfaces on engine block Figure 10-87
and oil pan are clean. Tool Required
2. Put new oil pan gaskets (5) on the oil pan (4) J 35621 Rear Seal Installer
(figure 10-86) Install or Connect
3. Carefully install oil pan (4), nuts (3) and bolts 1. Make sure any burrs and rust are removed
(1 and 2) on the engine. from crankshaft chamfer. Clean the sealing
surface on the crankshaft with a non-abrasive
cleaner.
2. Apply clean engine oil to the inner and outer
diameters of the seal.
3. Put the seal on the J 35621 Rear Seal Installer
(figure 10-87). Install the seal and tool on the
crankshaft by threading the tool screws into
the tapped holes of the crankshaft.
4. Tighten the screws with a screwdriver to be
sure the seal and tool are square to the crank-
shaft.
5. Turn the tool handle until it bottoms. Remove
the tool.

131-105

Figure 10-86 Oil Pan and Gaskets

Tighten
• Oil pan-to-crankcase bolts to 9 N•m (80 lb.
in.)
• Oil pan-to-front cover bolts to 5 N•m (45 lb.
in.)
• Nuts to 19 N•m (165 lb. in.)
600-248

Figure 10-87 Rear Seal Installer

10-40 IES 131 8/99

3.0L Assembly of Engine

HYDRAULIC LIFTER INSTALLATION Tighten

• Front left cylinder head bolt to 115 N•m (85
Install or Connect
lb. ft.)
• All remaining cylinder head bolts to 122 N•m
CAUTION (90 lb. ft.)
Install all new hydraulic lifters when a new
camshaft is installed. If any new hydraulic lifters
are installed, change the engine oil and filter.

1. Molly lube to camshaft end of hydraulic lifters.

2. Hydraulic lifters in the same bore from which
they were removed.

CYLINDER HEAD INSTALLATION

131-139
Figures 10-88 and 10-89
Figure 10-89 Cylinder Head Torque Sequence
Install or Connect
1. Gasket (3) on the engine block (figure 10-88).
ROCKER ARM AND PUSHROD
2. Carefully lower the cylinder head (2) on engine
block and gasket, aligning dowel pins. INSTALLATION
3. Clean threads of bolts (1) and tapped holes in Figure 10-90
engine block.
Install or Connect
4. Apply Sealing Compound (GM part no. 1. Install pushrod (4), making sure the pushrod is
1052080) or equivalent to threads of cap seated properly in the hydraulic lifter.
screws. Install and tighten cap screws in
sequence and in gradual steps to final torque 2. Apply clean engine oil to mating surfaces of
(figure 10-89). rocker arms (2) and balls (3).

IMPORTANT: If new rocker arms and/or balls

are installed, apply “Molykote” or an equivalent
to their mating surfaces.
3. Install rocker arms, balls and nuts (1).

131-102

Figure 10-88 Cylinder Head

131-101

Figure 10-90 Rocker Arm and Pushrod

IES 131 8/99 10-41

Assembly of Engine INDUSTRIAL ENGINE SYSTEMS

ADJUST VALVES ROCKER ARM COVER

Figure 10-91 INSTALLATION
Adjust Figure 10-92
1. Put engine in the number one firing position Clean
using the following steps: • Remove all gasket material from sealing
A. Watch the number one cylinder rocker arms surface of covers and cylinder heads. Clean
to check for motion. sealing surfaces with a non-petroleum base
B. Turn the engine crankshaft clockwise, as solvent.
viewed from front of the engine, until the Install or Connect
mark on the crankshaft pulley aligns with the 1. New gasket (5) in rocker arm cover.
“O” mark on the timing tab (figure 10-91).
2. Cover (2) and gasket on cylinder head. Install
C. As the mark moves toward the timing tab, if bolts (3) and reinforcements (4).
the number one cylinder rocker arms move,
Tighten
the engine is in the number four firing posi-
tion. Turn the crankshaft one more revolu- • Cap screws to 8 N•m (70 lb. in.)
tion to put the engine in the number one 3. Connect PCV hose to rocker arm cover.
firing position.

131-140 131-100

Figure 10-91 Placing Engine in Number 1 Firing Figure 10-92 Rocker Arm Cover
Position
FRONT COVER AND CRANKSHAFT
2. With the engine in the number one firing posi- SEAL INSTALLATION
tion, the following valves can be adjusted:
Figures 10-93 and 10-94
• Exhaust # 1 and #3, Intake #1, #2, and #4
Tool Required:
3. Adjust valves by: J 35468 Front Seal Installer
A. Loosening the adjusting nut until pushrod
can be moved or rotated. NOTICE: The front crankshaft seal can be installed
in the cover with the cover on the engine. Use J
B. Tighten the adjusting nut just until all motion
35468 Seal Installer (1) to install a new seal with the
is removed.
metal shoulder side of seal away from the engine
C. Turn adjusting nut one-half to one addition- (figure 10-93).
al turn.
Clean
4. Turn crankshaft one revolution clockwise until
• Clean gasket material from the mounting
the “O” mark and the pulley mark are aligned.
surfaces of the front cover and engine
Repeat Step 4 to adjust the following valves:
block.
• Exhaust #2 and #4; Intake # 3.

10-42 IES 131 8/99

3.0L Assembly of Engine

TORSIONAL DAMPER
INSTALLATION
Figure 10-95
Tool Required:
J 5590 Torsional Damper Installer

IMPORTANT: The inertia weight (outer) section

of the torsional damper is assembled to the hub
with a rubber type material. Use the correct tool
131-096 and installation procedures or distortion of the
Figure 10-93 Installing Front Cover Seal with inertia weight section of the hub will destroy the
Cover on Engine effectiveness of the torsional damper.
Install or Connect
Install or Connect 1. Small amount of engine oil on seal contact
area of damper.
1. Install new seal in cover using J-35468 Seal
Installer (1) (figure 10-93). Keep the side of the 2. Torsional damper on the crankshaft and align
seal with the metal shoulder away from the the damper with the key in the crankshaft.
engine. 3. Use J 5590 Torsional Damper Installer or a
2. Install new gasket on front cover. Use gasket hollow driver to push torsional damper tight
cement to hold gasket in place. against shoulder of crankshaft.
3. Apply clean engine oil to sealing lips of seal (1) 4. Apply a small amount of RTV sealant to
(figure 10-94). Carefully install front cover and torsional damper key-to-crankshaft joint.
bolts.
Tighten
• Front cover bolts to 9 N•m (80 lb. in.)

131-097

131-090 Figure 10-95 Installing Torsional Damper

Figure 10-94 Installing Front Cover Seal with
Cover Off Engine

IES 131 8/99 10-43

Assembly of Engine INDUSTRIAL ENGINE SYSTEMS

COOLANT PUMP INSTALLATION OIL FILTER BYPASS VALVE

Install or Connect INSTALLATION
1. Coolant pump and new gasket. Install or Connect
1. Install new valve using a 9/16 in. thin wall deep
NOTICE: Refer to “Notice” on page 1.
socket and a hammer.
2. Coolant pump bolts. 2. Install oil filter.
Tighten
• Bolts to 25 N•m (18 lb. ft.) FLYWHEEL AND HOUSING
3. Coolant pump pulley and bolts. INSTALLATION
Tighten Figures 10-96 and 10-97
• Bolts to 30 N•m (22 lb. ft.) Clean
INTAKE/EXHAUST MANIFOLD • Clean mating surfaces of flywheel and crank-
shaft.
INSTALLATION
Install or Connect
Install or Connect 1. Align dowel hole in flywheel with dowel pin on
1. Install new gasket on cylinder head with the crankshaft to install flywheel. Install and tight-
metallic side towards the manifold. en bolts (figure 10-96).
2. Apply Loctite® to threads of bolts that enter
any water chambers.
3. Carefully install manifold and bolts. Tighten
bolts in an alternating sequence in two steps.
Tighten
• Manifold bolts to:
- first: 20 N•m (15 lb. ft.)
- then: 41 N•m (30 lb. ft.)
4. Install alternator bracket. Make sure alternator
pulley is in alignment with coolant pump pulley.
5. Adjust alternator belt to specification.
Measure 131-098

• Alternator belt deflection 12 - 15 mm (0.47 - Figure 10-96 Flywheel and Bolts

0.59 in.)

10-44 IES 131 8/99

3.0L Assembly of Engine

Tighten ENGINE SETUP AND TESTING

• Flywheel bolts to 88 N•m (65 lb. in.)
After overhaul, the engine should be tested before
2. Check flywheel runout using a dial indicator. If installing it in the vehicle. If a suitable test stand is
runout is excessive, remove flywheel, check not available, the following procedure can be used
and clean mounting surfaces and install after the engine has been installed.
flywheel. Check runout again.
1. Fill the crankcase with the proper quantity and
Measure grade of engine oil.
• Maximum flywheel runout: 0.20 mm (0.008
in.) IMPORTANT: If a new camshaft or hydraulic
lifters were installed, add Engine Oil Supple-
3. Install flywheel housing, bolts and lockwash-
ment (GM P/N 1052367) or equivalent to the
ers.
engine oil.
Tighten
2. Fill the cooling system with the proper quantity
• Flywheel housing bolts to 34 - 41 N•m (25 -
and quality of engine coolant.
30 lb. ft.)
3. Crank the engine several times. Listen for any
4. Install flywheel coupler, bolts and lockwashers.
unusual noises or evidence that any parts are
Tighten binding.
• Flywheel housing bolts to 34 - 41 N•m (25 - 4. Start the engine and listen for unusual noises.
30 lb. ft.)
5. Run the engine at about 1000 rpm until the
engine is at operating temperature.
6. Listen for sticking lifters and other unusual
noises.
7. Check for oil and coolant leaks while the
engine is running.

131-099

Figure 10-97 Flywheel and Housing Components

IES 131 8/99 10-45

Assembly of Engine INDUSTRIAL ENGINE SYSTEMS

THIS PAGE WAS INTENTIONALLY LEFT BLANK

10-46 IES 131 8/98

3.0L Engine Torque Specifications

3.0L ENGINE TORQUE SPECIFICATIONS

Oil Pan Drain Bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 N•m (33 lb. ft.)

Coolant Drain Plug. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 N•m (11 lb. ft.)

Main Bearing Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 N•m (65 lb. ft.)

Connecting Rod Cap Nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 N•m (45 lb. ft.)

Main Bearing Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 N•m (65 lb. ft.)

Main Bearing Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 N•m (65 lb. ft.)

Oil Pump Cover Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 N•m (60 lb. in.)

Camshaft Thrust Plate Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 N•m (80 lb. in.)

Oil Pump-to-Crankcase Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 N•m (120 lb. in.)

Rear Crankshaft Oil Seal Retainer Stud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 N•m (15 lb. in.)

Rear Crankshaft Oil Seal Retainer Nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.3 N•m (135 lb. in.)

Oil Pan-to-Crankcase Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 11 N•m (80 - 100 lb. in.)

Oil Pan-to-Front Cover Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 11 N•m (80 - 100 lb. in.)

Oil Pan Nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 - 20 N•m (150 - 180 lb. in.)

Front Left Cylinder Head Bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 N•m (85 lb. ft.)

All Cylinder Head Bolts Except Front Left. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 N•m (90 lb. ft.)

Rocker Arm Cover Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 - 8 N•m (40 - 70 lb. in.)

Front Cover Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 10 N•m (72 - 90 lb. in.)

Coolant Pump Bolts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 N•m (18 lb. ft.)

Coolant Pump Pulley Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 N•m (22 lb. ft.)

Intake and Exhaust Manifold Bolts:

First Pass:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 N•m (15 lb. ft.)
Final Pass: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 N•m (30 lb. ft.)

Flywheel Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 N•m (65 lb. ft.)

Flywheel Coupler Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 - 41 N•m (25 - 30 lb. ft.)

Flywheel Housing Bolts and Nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 - 41 N•m (25 - 30 lb. ft.)

Spark Plugs (New) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 N•m (22 lb. ft.)

(All Subsequent Installations) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 N•m (15 lb. ft.)

IES 131 8/99 10-47

Engine Specifications INDUSTRIAL ENGINE SYSTEMS

3.0L ENGINE SPECIFICATIONS

GENERAL DATA
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .L4
Displacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.0L (181 C.l.D.)
Bore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101.60 mm (4.00 in.)
Stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91.44 mm (3.60 in.)
Compression Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . .8.2 to 1 (RN, RS, RA) or 9.25 to 1 (RM, RF)
Firing Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 - 3 - 4 - 2
Oil Pressure (Minimum HOT) . . . . . . . . .28 kPa (4 psi) / Idle RPM - 207 - 414 kPa (30 - 60 psi) / 2000 RPM
CYLINDER BORE
Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . .101.587 - 101.663 mm (3.9995 - 4.0025 in.)
Out of Round Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0254 mm (0.001 in.) Maximum
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0508 mm (0.002 in.) Maximum
Taper Production Trust Side . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0127 mm (0.0005 in.) Maximum
Relief Side . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0127 mm (0.0005 in.) Maximum
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0254 mm (0.001 in.) Maximum
PISTON
Clearance Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0635 - 0.0889 mm (0.0025 - 0.0035 in.)
Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0889 mm (0.0035 in.) Maximum
PISTON RINGS
Compression
Groove Production Top . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0305 - 0.737 mm (0.0012 - 0.0029 in.)
Clearance Second . . . . . . . . . . . . . . . . . . . . . . . .0.0305 - 0.737 mm (0.0012 - 0.0029 in.)
Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0991 mm (0.0039 in.) Maximum
Gap Production Top . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.254 - 0.508 mm (0.0010 - 0.0020 in.)
Second . . . . . . . . . . . . . . . . . . . . . . . . . .0.4318 - 0.635 mm (0.017 - 0.025 in.)
Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.889 mm (0.035 in.) Maximum
0il
Groove Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0254 - 0.1524 mm (0.001 - 0.006 in.)
Clearance Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.1778 mm (0.007 in.) Maximum
Gap Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.254 - 0.762 mm (0.010 - 0.030 in.)
Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.016 mm (0.040 in.)
PISTON PIN
Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . .23.5458 - 23.5509 mm (0.9270 - 0.9272 in.)
Clearance Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0076 - 0.0178 mm (0.0003 - 0.0007 in.)
in Piston Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0254 mm (0.001 in.) Maximum
Fit in Rod . . . . . . . . . . . . . . . . . . .0.0203 - 0.0406 mm (0.0008 - 0.0016 in.) Interference
INTAKE / EXHAUST MANIFOLD
Surface Flatness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.254 mm (0.010 in.) Maximum
CYLINDER HEAD
Surface Flatness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.1778 mm (0.007 in.) Overall
FLYWHEEL
Surface Runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.2032 mm (0.008 in.) Maximum

10-48 IES 131 8/99

3.0L Engine Specifications

3.0L ENGINE SPECIFICATIONS (CONTINUED)

CRANKSHAFT
Main Journal
Diameter All . . . . . . . . . . . . . . . . . . . . . . . . . . .58.3667 - 58.4048 mm (2.2979 - 2.2994 in.)
Taper Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0059 mm (0.0002 in.) Maximum
Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0254 mm (0.001 in.) Maximum
Out of Round Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0059 mm (0.0002 in.) Maximum
Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0254 mm (0.001 in.) Maximum
Main Bearing Clearance
Production #1- #4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0254 - 0.0610 mm (0.001 - 0.0024 in.)
#5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0406 - 0.0889 mm (0.0016 - 0.0035 in.)
Service Limit #1 - #4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0254 - 0.0635 mm (0.001 - 0.0025 in.)
#5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0381 - 0.0889 mm (0.0015 - 0.0035 in.)
Crankshaft End Play . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0508 - 0.1524 mm (0.002 - 0.006 in.)
Crankshaft Runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0762 mm (0.003 in.) Maximum
Crankpin
Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . .53.2892 - 53.3273 mm (2.0980 - 2.0995 in.)
Taper Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0762 mm (0.0003 in.) Maximum
Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0254 mm (0.001 in.) Maximum
Out of Round Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0051 mm (0.0002 in.) Maximum
Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0254 mm (0.001 in.) Maximum
Rod Bearing Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0432 - 0.0686 mm (0.0017 - 0.0027 in.)
Clearance Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0762 mm (0.003 in.) Maximum
Rod Side Clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.1524 - 0.4318 mm (0.006 - 0.017 in.)
CAMSHAFT
Lobe Lift Intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.4247 mm (0.25294 in.)
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.4247 mm (0.25294 in.)
Service Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±0.0254 mm (±0.001 in.)
Journal Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . .47.4396 - 47.4904 mm (1.8677 - 1.8697 in.)
End Play . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0762 - 0.2032 mm (0.003 - 0.008 in.)
Sprocket Runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.1016 mm (0.004 in.) Maximum
Timing Sprocket Teeth Backlash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.1016 - 0.1524 mm (0.004 - 0.006 in.)
VALVE SYSTEM
Lifter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Hydraulic
Rocker Arm Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.75 to 1
Valve Lash Intake and Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1/2 to One Turn Down From Zero Lash
Face Angle Intake and Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45°
Seat Angle Intake and Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46°
Seat Runout Intake and Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0508 mm (0.002 in.) Maximum
Seat Width Intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.270 - 1.778 mm (0.050 - 0.070 in.)
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.524 - 2.032 mm (0.060 - 0.080 in.)
Stem Production Intake . . . . . . . . . . . . . . . . . . . . . . . .0.0254 - 0.0686 mm (0.0010 - 0.0027 in.)
Clearance Exhaust . . . . . . . . . . . . . . . . . . . . . . .0.0178 - 0.0686 mm (0.0007 - 0.0027 in.)
Service Intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0940 mm (0.0037 in.) Maximum
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.1194 mm (0.0047 in.) Maximum
Valve Spring Free Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52.324 mm (2.06 in.)
Pressure Closed . . . . . . . . . . . . . . .444 - 490 N @ 40.89 mm (100 - 110 Ibs. @ 1.61 in.)
Open . . . . . . . . . . . . . . . .925 - 987 N @ 30.99 mm (208 - 222 Ibs. @ 1.22 in.)
Installed Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41.91 mm (1.65 in.)
Valve Lift Intake and Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.2522 mm (0.443 in.)
Valve Spring Damper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Not Used

IES 131 8/99 10-49

Special Tool Usage INDUSTRIAL ENGINE SYSTEMS

SPECIAL TOOL USAGE

Tool # Description 3.0L 4.3L 5.7L 7.4L

J 21882 Oil Pickup Tube and Screen Installer X X

J 22102 Crankshaft Sprocket Installer X
J 23738-A Valve Seal Leak Detector X X X
J 24086-B Piston Pin Remover and Installer Set X X X X
J 24270 Ridge Reamer X X X X
J 24420 Crankshaft Gear Remover
J 28509 Crankshaft Sprocket Puller X X
J 3049-A Valve Lifter Remover X X X
J 33049 Camshaft Bearing Remover and Installer X
J 34673 Straightedge X X X X
J 35468 Crankshaft Front Seal Installer X X
J 35621 Crankshaft Rear Seal Installer X X X
J 36669 Torque Angle Meter X
J 36996 Bearing Remover X
J 38834 Balance Shaft Bearing Service Kit X
J 38841 Crankshaft Rear Oil Seal Installer X
J 39046 Torsional Damper Puller and Installer X X X X
J 5239 Connecting Rod Guide Set X X X X
J 5590 Crankshaft Sprocket Installer X X X
J 5715 0.0762 mm (0.003 in.) Reamer X X X X
J 5790-B Hydraulic Lifter Leakdown Tester X X X
J 5802-01 Stud Remover X
J 5825-A Crankshaft Sprocket Puller X X
J 5830-02 Reamer Set J 5830-1, 5830-2, and 5830-3 X X X X
J 5830-1 0.08 mm (0.003 in.) Reamer X X X X
J 5830-2 0.38 mm (0.015 in.) Reamer X X X X
J 5830-3 0.76 mm (0.030 in.) Reamer X X X X
J 6036 0.3302 mm (0.013 in.) Reamer X X X X
J 6098-01 Camshaft Bearing Remover and Installer X X X X
J 6621 0.13 mm (0.005 in.) Reamer X X X X
J 6880 Stud Installer X
J 7872 Magnetic Base Dial Indicator X X X X
J 8001 Dial Indicator X X X X
J 8037 Ring Compressor X X X X
J 8056 Valve Spring Tester X X X X
J 8062 Valve Spring Compressor X X X X
J 8087 Cylinder Bore Gage X X X X
J 8089 Wire Brush X X X X
J 8092 Driver Handle X X X
J 8101 Valve Guide Cleaning Tool X X X X
J 8369 Oil Pickup Tube Installer X
J 9290-01 Valve Lifter Remover X X X X
J 9510 Piston Support Tool X

10-50 IES 131 8/98