Mitsubishi diesel engines Service Manual

FOREWORD

This service manual describes the specifications as well as the maintenance and
adjustment procedures for Mitsubishi diesel engines. This manual also includes the
detailed information on basic and special tools as the need arises.

The Mitsubishi diesel engines can offer highly efficient and reliable performance for
many years to come, which, however, only can be achieved through the proper
handling and the periodical inspection/maintenance work exercised in according to
the procedures of disassembly, inspection/adjustment and reassembly described in this
manual.

Before attempting any work on your engine, thoroughly read this manual to
familiarize with the engine and the required procedures of the work.

All information contained in this manual is based on the engine produced at the time
of publication and is subject to change as the engine improved without notice.

Pub. No. 99619-12140

HOW TO USE THIS MANUAL

This Service Manual describes the specifications of Mitsubishi diesel engines (land and standard applications)
and relevant service standards, as well as the procedures for servicing the engines such as for disassembly,
inspection, repair and reassembly. This manual is divided into Groups. Each Group covers a specific area of
the engine.
The fuel injection pump, the governor and the turbocharger are handled in a separate manual.

Major contents of Groups are listed on the “General Contents” page. Detailed contents of each Group are
listed on the first page of that Group.

For information on the operations and recommended inspection/maintenance schedule of forklift trucks,
please refer to the operator’s manual for the forklift truck. For information on components/parts and spares
ordering procedures, refer to the parts catalogue. For information on structures and functions, refer to
appropriate training materials.

1. Notes on descriptions

(1) Parts shown in Figures as well as in the text are numbered in the order of disassembly.
(2) Inspecting points during disassembly are shown in the Disassembly figures by enclosing in the box.
(3) Service standards for inspection and repair are listed on the appropriate pages of this manual where the

relevant descriptions are made. Also, a comprehensive listing of service standards is provided in Group

1.

(4) Parts reassembly sequence is provided below the Figure of that reassembly in the form of ⑤→④→③

→②→①.

(5) In this manual, the following marks are provided to draw the reader’s attention to the safety notes

described under the marks.

････ This indicates a dangerous situation which can highly likely result in death or

serious injury unless avoided.

････ This indicates a potentially dangerous situation which may possibly lead to

death or serious injury unless avoided.

････ This indicates a potentially dangerous situation which may cause minor to

moderate injury unless avoided.

････This indicates a potential danger in which property damage may result unless

avoided.

Note: ････ This stresses important points or provides useful tips on engine operations and

service.

(6) Wherever hardware tightening requires the application of engine oil, “WET” is mentioned. If not

mentioned, tighten the hardware “dry” (engine oil should not be applied).

2. Terms

Nominal value ······This is the nominal dimension of the part being measured.

Standard value ······ This is the dimension of the individual part being measured, the clearance between the

parts in question, or the standard performance in question. Standard values have been
arranged within the range appropriate for the inspection being carried out, and are not
necessarily the design values.

Limit·····················Parts that have reached the limit value should be replaced or repaired whichever is

appropriate.

3. Abbreviations and standards

・BTDC = Before Top Dead Center
・ATDC = After Top Dead Center
・BBDC = Before Bottom Dead Center
・ABDC = After Bottom Dead Center
・TIR = Total Indicator Reading
・API = American Petroleum Institute
・ASTM = American Society for Testing and Materials
・JIS = Japan Industrial Standards
・LLC = Long Life Coolant
・MIL = Military Specifications
・MSDS = Material Safety Data Sheets
・SAE = Society of Automotive Engineers

4. Units

Values shown in this manual are based on SI units (International System of Units). The corresponding metric
values are shown in ( ) immediately after the SI values. The SI to metric conversions are based on the
following.

・Pressure: 1 MPa = 10.197 kgf/cm

2

・Torque: 1 N･m = 0.10197 kgf･m
・Force: 1 N = 0.10197 kgf
・Horsepower: 1 kW = 1.341 HP = 1.3596 PS
・Meter of mercury: 1 kPa = 0.7 cmHg
・Meter of water: 1 kPa = 10.197 cmH

2

O (cmAq)

・Rotational speed: 1 min

-1

= 1 rpm

Group No. Group Name Page

0 SAFETY CAUTIONS 0 - 1

GENERAL 1 - 1
SERVICE STANDARDS 1 -11
TOOLS LIST 1 -21
OVERHAUL TIMING 1 -25

1

REMOVAL PREPARATIONS 1 -29

ENGINE MAIN PARTS - DISASSEMBLY 2 - 1
ENGINE MAIN PARTS - INSPECTION AND

CORRECTION

2 -17

2 Engine Main Parts

ENGINE MAIN PARTS - REASSEMBLY 2 -33
FUEL SYSTEM - REMOVAL 3 - 1

FUEL SYSTEM - DISASSEMBLY,
INSPECTION AND REASSEMBL Y

3 - 9

3 Fuel System

FUEL SYSTEM - INSTALLATION 3 -25
OIL SYSTEM - REMOVAL 4 - 1

OIL SYSTEM - DISASSEMBLY,
INSPECTION AND REASSEMBL Y

4 - 5

4 Lubrication System

OIL SYSTEM - INSTALLATION 4 - 9
COOLING SYSTEM - REMOVAL 5 - 1

COOLING SYSTEM - DISASSEMBLY,
INSPECTION AND REASSEMBL Y

5 - 5

5 Cooling System

COOLING SYSTEM - INSTALLATION 5 - 9
INLET AND EXHAUST SYSTEMS -

REMOVAL

6 - 1

INLET AND EXHAUST SYSTEMS ­DISASSEMBLY, INSPECTION AND
REASSEMBLY

6 - 5

6

Inlet and Exhaust
Systems

INLET AND EXHAUST SYSTEMS ­INSTALLATION

6 - 7

ELECTRICAL SYSTEM - REMOVAL 7 - 1
ELECTRICAL SYSTEM - DISASSEMBLY,

INSPECTION AND REASSEMBL Y

7 - 7

7 Air starter System

ELECTRICAL SYSTEM - INSTALLATION 7 -25
ENGINE - INSPECTION / ADJUSTMENT 8 - 1
RUNNING-IN TRIAL 8 -12

8

Engine -
Inspection/Adjustment,
Running-in Trial and
Performance Test

PERFORMANCE TEST 8 -13

9 Others

DISASSEMBL Y AND REASSEMBLY OF
GENERAL PARTS

9 - 1

Supplement
Engine Inspection Sheets

GENERAL CONTENTS

Warning Risk of fire and explosion ···0-2

●Never use open fire ······························0-2

●Keep things tidy around the engine ··········0-2

●Do not open the crankcase until it has

cooled down

········································0-2

●Pay attention to fuel and oil leakage

·········0-2

●Use explosion-proof light

························0-2

●Prevent short circuit

······························0-2

●Keep fire extinguisher and first-aid kit
at hand

··············································0-2

Warning Risk of entanglement into

the machine························0-3

●Keep guards on the rotating parts ············0-3

●Ensure safety in the surrounding area

when starting the engine

························0-3

●Keep away from rotating parts while th e
engine is running

··································0-3

●Lockout/tagout

·····································0-3

●Always stop the engine before any
inspection/service

·································0-3

●Remove the turning gear after use

···········0-3

Warning Risk of burn ························0-4

●Do not touch the engine while it is
running or for a while after it is stopped

·····0-4

●Be careful when opening/closing the
radiator cap

·········································0-4

●Replenish coolant only when
the coolant in the system is cold

··············0-4

●Do not remove heat insulating material ·····0-4

Warning Exhaust gas is

poisonous···························0-4

●Ensure good ventilation while the
engine is running

··································0-4

Warning Hearing difficulty·················0-4

●Wear ear protector································0-4

Warning Beware of falling engine·····0-5

●Exercise caution when lifting the engine····0-5

●Do not climb on the engine

·····················0-5

●Secure your foothold when carrying out
service

···············································0-5

Caution Use correct engine oil

and LLC······························0-5

●Only use the specified fuel, engine oil
and coolant (LLC)

·································0-5

●Handle LLC with care

····························0-5

●Lawful disposal of waste oil and
coolant

···············································0-5

Caution Handling of battery·············· 0-6

●Handle the battery with care····················0-6

Caution How to handle

emergencies·······················0-6

●Engine overheat - Idle to cool down,
then stop the engine

·····························0-6

●Never restart the engine after a sudden
stop unless the cause is eliminated

··········0-6

●Stop the engine immediat ely upon oil
pressure drop

······································0-6

●Stop the engine immediat ely upon broken
fan belt

···············································0-6

Caution How to handle

emergencies·······················0-6

●Engine overheat - Idle to cool down,
then stop the engine

·····························0-6

●Never restart the engine after a sudden
stop unless the cause is eliminated

··········0-6

●Stop the engine immediat ely upon oil
pressure drop

······································0-6

●Stop the engine immediat ely upon broken
fan belt

···············································0-6

Caution Other considerations···········0-7

●Never alter or modify the engine ··············0-7

●Do not tamper with sealing

·····················0-7

●Daily and periodical inspection

················0-7

●Running-in period

·································0-7

●Warming up the engine

··························0-7

●Do not overload the engine·····················0-7

●Cooling down the engine

························0-7

●Do not spill water onto the engine ···········0-7

●Air cleaner maintenance precautions

········0-8

●Observe safety rules at work sites

············0-8

●Wear appropriate clothes and protective
gear

···················································0-8

●Use appropriate tools when carrying out service

0-8

●Do not operate the starter continuously

·····0-8

●The battery switch must be kept ON while
the engine is running

·····························0-8

●Precautions for road transport

·················0-8

SAFETY CAUTIONS

SAFETY CAUTIONS

0 - 2

Warning Risk of fire and explosion

●Never use open fire

When topping up or replacing fuel
or engine oil, or cleaning parts in
wash oil, do not light a match,
smoke or use any other open fire
nearby. Doing these is extremely
dangerous as fuel and oils can catch fire.
Completely wipe off any spilt fuel or engine oil as
they are flammable and can be a fire hazard.
Store fuel and engine oil in a well-ventilated place.
Firmly tighten the cap of the container.

●Keep things tidy around the engine

Keep fuel, engine oil or any other flammables as
well as explosives and other dangerous materials
away from the engine. These materials can ignite
and explode.
Keep the engine and the surrounding area free of
waste, dirt, foreign matter, etc. These substances
can be a fire hazard and invite overheating. In
particular, ensure that the top of the battery is clean
after service operations. Any waste left on the
battery can cause short circuit.
Keep a running engine at least 1 m (3.3 ft.) away
from the surrounding building or equipment to
eliminate the risk of fire.

●Do not open the crankcase until it has
cooled down

Do not attempt to open the crankcase side cover
immediately after the engine is stopped. Wait at
least 10 minutes until the engine has sufficiently
cooled down.
If fresh air flows into the crankcase with the engine
still hot, the remaining mist of oil may ignite and
cause explosion.

●Pay attention to fuel and oil leakage

If leakage of fuel or oil is found, immediately take
measures to stop it.
If leaking fuel or engine oil spills over the heated
engine, fire may start, possibly leading to bodily
injury or equipment damage.

●Use explosion-proof light

When checking fuel, engine oil, coolant, battery
electrolyte, etc., use explosion-proof light. If
ordinary light is used, these fluids may ignite and
explode.

●Prevent short circuit

Before inspecting or servicing the
electrical/electronic system, disconnect the negative
(-) cable from the battery terminal. Failure to
observe this can cause the circuit to short, possibly
starting a fire.
Loose terminals and damaged cables/wires can
cause short circuit or even fire. Before carrying out
service operation, check for loose or damaged
components and repair or replace as required.

●Keep fire extinguisher and first-aid kit
at hand

Keep a fire extinguisher at hand.
Become familiar with the handling
of the fire extinguisher.
Store a first-aid kit at the designated
place. The kit should be kept fully
supplied so that it can serve the purpose at any time.
Establish a set of actions to take in the event of fire
or accident, including emergency contact numbers
and means of communication.

SAFETY CAUTIONS

0 - 3

Warning Risk of entanglement into the machine

●Keep guards on the rotating parts

Ensure that all guards are correctly
installed over the rotating parts of
the engine. Damaged or loose
guards should be repaired.
Never attempt to remove the
camshaft cover, rocker cover or any other guards
form rotating parts while the engine is running.
Never leave exposed the drive belts and related
couplers for auxiliaries and radiator. They should
also be covered with guards.
Never remove these guards.

●Ensure safety in the surrounding area
when starting the engine

Before starting the engine, ensure that no one is near
the electric power generator and that no tools or
foreign matter are left behind. Shout to people
around you so that they will know you are starting
the engine.
Never start the engine if a “Do not start” tag or any
other similar message is posted on the starter switch,
etc.

●Keep away from rotating parts while
the engine is running

Never stand near the rotating parts
while the engine is running.
Do not place objects near the rotating
parts that are likely to be caught by
these parts.
Should any part of human body (or tool) is caught by
the rotating parts, dismemberment or other bodily
injury will result.

●Lockout/tagout

Perform lockout/tagout before carrying out any
inspection/service.
Lockout/tagout is an ideal way of disconnecting the
machine/equipment from the power source.
To lockout/tagout, remove the starter switch key,
place the battery switch in the “OFF” position, and
post a “Do not start” tag or other similar message on
the starter switch.
The starter switch key should then be carried by the
person who is going to perform inspection/service.
If an air start system is used, close the air tank source
valve and post a “Do not open” tag or other similar
message.

●Always stop the engine before any
inspection/service

Always stop the engine before performing any
inspection/service. Never attempt to adjust belt
tension while the engine is running. Otherwise, the
operator runs a great risk of becoming entangled into
the rotating parts and seriously injured.

●Remove the turning gear after use

Be sure to remove the turning gear after use. Never
start the engine with the turning gear still installed or
“engaged.” Otherwise, the engine will break and
possibly someone may become injured.

SAFETY CAUTIONS

0 - 4

Warning Risk of burn

●Do not touch the engine while it is
running or for a while after it is
stopped

Never touch any part of the engine
while it is running or for a while after
it is stopped. Otherwise, you may
become burned.
Use a coolant temperature gauge to confirm that the
engine has sufficiently cooled down before
performing any inspection/service.

●Be careful when opening/closing the
radiator cap

Never attempt to open the radiator cap while the
engine is running and for a while after it is stopped.
Stop the engine and wait until the coolant
temperature has sufficiently dropped before opening
the cap.
Slowly open the radiator cap to allow the internal
pressure to escape. To prevent possible burn, wear
thick rubber gloves or cover the cap with cloth to
protect your hands from escaping vapor.
Tighten the radiator cap firmly.
Coolant is extremely hot while the engine is running
or for a while after the engine is stopped. You may
become burned by extremely hot vapor or coolant
that will gush out if the radiator cap is opened.

● Replenish coolant only when the
coolant in the system is cold

Do not replenish coolant for a while after the engine
is stopped. Replenish coolant when the coolant in
the system is sufficiently cold. Otherwise, you may
become burned.

● Do not remove heat insulating
material

The exhaust system components become extremely
hot and therefore are covered with heat insulating
material. Never remove the material. If the material
needs to be removed at all for inspection/service, be
sure to install it again after the operation.

Warning Exhaust gas is

poisonous

● Ensure good ventilation while the
engine is running

If the engine is installed inside a
building and the exhaust gas is
directed outside through a duct,
regularly check the duct for any
leakage through the joints etc.
Do not run the engine in a building (warehouse,
tunnel, etc.), confined space, or other poorly
ventilated places if the engine is used for a portable
generator. If the engine needs to be run in a building
at all, ensure to direct the exhaust gas outside and
provide sufficient ventilation. Also, take care not to
direct the exhaust gas towards nearby plants or
animals, if any.
Engine exhaust gas contains carbon monoxide and
other substances that are harmful to humans.
Running the engine in a poorly ventilated place can
cause exhaust gas poisoning.

Warning Hearing

difficulty

●Wear ear protector

W ear ear protector whenever entering
the engine room. Otherwise, the
combustion and mechanical noises
may cause you to develop hearing
difficulty.

SAFETY CAUTIONS

0 - 5

Warning Beware of

falling engine

● Exercise caution when lifting the
engine

The wire rope used to lift the engine
should have enough strength to
withstand the weight of the engine.
Attach the specified lifting gear onto the
lifting hangers on the engine.
Ensure that the engine is well balanced when it is
lifted by taking into account the engine’s center of
gravity.
The angle of wire rope relative to the lifting hangers
should be maintained at 60º or less. Above this, the
hangers may be subjected to overload and break.
If direct contact between the wire rope and the
engine is anticipated, protect them from damage by
covering them with cloth or other soft material.

● Do not climb on the engine

Do not climb onto the engine, nor place a foot on the
components on the side of the engine.
Otherwise, you may not only break the engine
components but also fall and become injured.
Use a stool or a platform to work on the top of the
engine. Be careful not to slip and fall.

● Secure your foothold when carrying
out service

Use a stable stool or platform when
working on the top of the engine or
other areas of the engine difficult to
reach.
Do not use a rickety stool nor
substitute a box of parts. Otherwise, you may fall
and become injured.
Do not leave anything on the stool.

Caution Use correct

engine oil and LLC

● Only use the specified fuel, engine oil
and coolant (LLC)

Only use the fuel, engine oil and coolant (LLC) that
are specified in this manual. Handle them with
sufficient care.
Using fluids other than those specified in this
manual or incorrect use of those specified in this
manual will lead to many problems and may
possibly cause failures.
Use the specified engine oil and LLC according to
the instructions of MSDS (Material Safety Data
Sheets) issued by and available from the
manufacturers.

● Handle LLC with care

LLC is a strong alkali. Be careful not to drink it by
mistake or allow it to contact your eyes.
Old coolant (containing LLC) that has been drained
off is toxic. Do not dispose of it carelessly. Dispose
of it in accordance with the applicable laws and
regulations.

● Lawful disposal of waste oil and
coolant

Do not dispose of waste oil or coolant carelessly.
Doing so is harmful to the environment and is
prohibited by law.
Harmful substances such as waste oil and coolant
should be disposed of in a manner that complies with
the applicable laws and regulations.

SAFETY CAUTIONS

0 - 6

Caution Handling of

battery

● Handle the battery with care

・ Batteries emit hydrogen and

oxygen gases, both of which are
flammable. Never use open fire or
generate sparks near the battery.
Otherwise, these gases may ignite and explode.

・ Do not use the battery if the electrolyte level has

dropped below the minimum line. Otherwise, the
battery may explode.

・ Be careful not to inadvertently place a metal

object such as tool between the battery terminals.

・ Always disconnect the negative (-) terminal first,

then the positive (+) terminal, from the battery.
Always connect the positive (+) terminal first,
then the negative (-) terminal, to the battery.

・ Recharge the battery in a well ventilated place,

with all battery plugs removed.

・ The battery terminals should have a positive

connection. Loose terminals can generate sparks,
possibly causing the battery to explode.

・ Before servicing or performing electric welding

on the electrical/electronic system, position the
battery switch in the OPEN/OFF position or
disconnect the negative (-) terminal of the battery
to isolate the electrical/electronic circuit.

・ The battery electrolyte contains dilute sulfuric

acid. Incorrect handling may lead to loss of
eyesight or burn. Never drink battery electrolyte.

・ Wear protective goggles and rubber gloves when

maintaining the battery (replenishing, recharging,
etc.).

・ If your skin or clothing has come into contact with

battery electrolyte, immediately wash the affected
area with plenty of water and then thoroughly
clean with soap.

・ Should your eyes come into contact with battery

electrolyte, loss of eyesight may result.
Immediately wash your eyes with plenty of fresh
water and seek medical attention immediately.

・Should you inadvertently drink battery electrolyte,

repeatedly gargle with plenty of water and then
drink plenty of water. Seek medical attention
immediately.

Caution How to handle

emergencies

● Engine overheat - Idle to cool down,
then stop the engine

In the event of engine overheat, do not stop the
engine immediately. Doing so may cause the
coolant temperature to rise quickly and the engine
may seize. Instead, run the engine at low idle for a
while to cool it down. Then, stop the engine. Do not
attempt to replenish coolant for a while after the
engine is stopped. Otherwise, the cylinder head etc.,
which may still be hot, is cooled down rapidly and
may break. Wait until the engine is sufficiently cold
and then top up slowly.

● Never restart the engine after a
sudden stop unless the cause is
eliminated

If the engine has suddenly stopped with some alert
signals, do not restart immediately. Otherwise, the
engine may seriously become damaged. Locate and
eliminate the cause before restarting.

● Stop the engine immediately upon oil
pressure drop

If the oil pressure has dropped, immediately stop the
engine. Otherwise, bearings etc. may seize. Inspect
the oil system and components.

● Stop the engine immediately upon
broken fan belt

If the fan belt has broken, immediately stop the
engine. Otherwise, the engine will overheat. Also,
coolant vapor will gush out from the reserve tank
and radiator and you may get burned.

SAFETY CAUTIONS

0 - 7

Caution Other considerations

● Never alter or modify the engine

Altering or modifying the engine in any way will
nullify the warranty.
A modified engine may not only break but also lead
to injury.

● Do not tamper with sealing

To help ensure trouble-free operation of the engine,
the fuel control link has been sealed to achieve the
correct fuel injection volume and engine speed. If
the sealed setting is tampered with, the following
will result and the correct functioning of the engine
is no longer guaranteed.

・ Sliding and rotating parts will wear faster.
・ Various parts will seize/become damaged.
・ The engine will consume more fuel and oil.
・ The governor and fuel injection volume go out of

balance, reducing the engine performance.

● Daily and periodical inspection

Perform the daily and periodical inspection in
accordance with the Operation and Maintenance
Manual.
Failure to observe the instructions of the manual
may lead to many problems, and the various engine
parts may eventually fail, possibly causing a serious
accident.

● Running-in period

A brand new engine requires a running-in period of
50 hours, during which never put the engine under
severe load. Otherwise, the service life of the engine
will be reduced.

● Warming up the engine

Before starting work, warm up the engine by
running it at low idle for 5 to 10 minutes.
Warming up the engine will not only smoothen the
operation of various engine parts but also help
extend its service life. It also helps maximize the
performance and achieve economical running of the
engine.
Do not warm up the engine longer than necessary.
Doing so facilitates carbon deposit on the cylinders,
possibly leading to poor combustion.

● Do not overload the engine

Do not continue to run the engine if it emits black
smoke.
Overloaded running of the engine (accompanied by
black smoke) not only consumes excessive fuel but
also facilitates carbon deposit and thus shortens the
service life of the engine.

● Cooling down the engine

Before stopping the engine, cool it down (by running
it at low idle) for 5 to 6 minutes.
Stopping the engine suddenly while it is heavily
loaded will result in some areas of the engine
remaining extremely hot for a while, which is
detrimental to the long service life of an engine.
While the engine is being run at low idle for cooling,
check the engine for any problems.

● Do not spill water onto the engine

Ensure that no rainwater etc. enters into the engine
from the exhaust or inlet manifold, or via any other
routes.
Do not run the engine while at the same time
washing it. Otherwise, cleaning fluid (water) may
be sucked into the engine.
If the engine is started with water trapped in the
combustion chambers, water hammering will result,
causing the engine to fail and possibly leading to a
serious accident.

SAFETY CAUTIONS

0 - 8

● Air cleaner maintenance precautions

Wear of engine parts is accelerated largely by the
dust contained in the intake air. Worn engine parts
will lead to various problems such as increased oil
consumption, reduced power and poor starting. Air
cleaner is effective in removing dust in the intake air.
When maintaining the air cleaner, observe the
following precautions.
・ Never attempt to service the air cleaner while the

engine is running.

・ When removing the air cleaner, take care not to

allow the dust trapped on the air cleaner to enter
into the inlet port.

・ If the engine is equipped with the dust indicator,

clean the air filter only when the indicator shows
clogging. Unnecessary maintenance (removal/
installation of the filter element) runs the risk of
allowing dust into the inlet port or damaging/
deforming the filter element.

● Observe safety rules at work sites

Whenever running or servicing the engine, always
observe the relevant safety rules in place.
If you are not in good shape, do not operate the
engine. Consult the site supervisor.
Poor physical conditions are accompanied by
reduced attention. Do not operate the engine if you
are not feeling well. Otherwise, you may incorrectly
handle the engine and cause an accident.
When working jointly with other people on the same
task, use signals to coordinate actions involved.

● Wear appropriate clothes and
protective gear

Whenever appropriate, including when using
compressed air, wear protective gear such as helmet,
face mask, safety shoes, dust mask, goggles and
gloves.
Working without appropriate protective gear may
lead to serious injury.

● Use appropriate tools when carrying
out service

When carrying out any service, use appropriate tools
and in correct ways.
Damaged tools should be replaced with new ones.

● Do not operate the starter
continuously

Do not operate the starter more than 10 seconds per
starting attempt. If the engine fails to start at the first
attempt, wait for at least 30 seconds before trying
again.
Do not run the starter continuously if the engine will
not start. Otherwise, the battery will go flat or the
starter will seize.

● The battery switch must be kept ON
while the engine is running

Do not turn off the battery switch while the engine is
running.
Otherwise, the instruments will become inoperative
and the diode or transistor of the alternator may
deteriorate.

● Precautions for road transport

When transporting the engine on public roads, the
weight, width and height of the electric power
generator should be taken into account while
observing the relevant laws regarding road traffic
and haulage, and vehicle restrictions and
requirements.

1. Overview ····························································································· 1 - 2

1.1 Outline Drawing··················································································· 1 - 2

1.2 Fuel System Schematic ········································································ 1 - 4

1.3 Oil System Schematic··········································································· 1 - 4

1.4 Cooling System Schematic···································································· 1 - 5

1.5 Inlet / Exhaust System Schematic··························································· 1 - 5

1.6 Engine Serial Number··········································································· 1 - 6

1.7 Engine Model and Application Codes ······················································ 1 - 6

2. Specifications ······················································································ 1 - 7

3. Disassembly / Reassembly Notes······················································· 1 - 9

3.1 Disassembly ······················································································· 1 - 9

3.2 Reassembly························································································ 1 - 9

GENERAL

GENERAL

1 - 2

1. Overview

1.1 Outline Drawing
S3L, S3L2

Oil filler

Exhaust manifold

Starter

Front end

Rear end

Left-hand side

Thermostat

Hanger

Alternator

Fan

V belt

Oil pan

Flywheel

Engine LH side view

Right-hand side

Fuel injection nozzle

Fuel injection pump

Water pump

Stop solenoid

Coolant drain plug

Flywheel housing

Oil level gauge

Oil filter

Oil drain plug

Inlet cover

Crankshaft pulley

Front end

Rear end

Engine RH side view

GENERAL

1 - 3

S4L, S4L2

Oil filler

Exhaust
manifold

Starter

Front end

Rear end

Left-hand side

Thermostat

Hanger

Alternator

Fan

V belt

Oil pan

Flywheel

Engine LH side view

Right-hand side

Fuel injection nozzle

Fuel injection pump

Water pump

Stop solenoid

Coolant drain plug

Flywheel housing

Oil level gauge

Oil filter

Oil drain plug

Inlet cover

Crankshaft pulley

Front end

Rear end

Engine RH side view

GENERAL

1 - 4

1.2 Fuel System Schematic

To fuel tank

From fuel tank

Fuel pump

Fuel filter

Fuel leak-off pipe

Fuel injection pipe

Fuel injection nozzle

Fuel injection pump

O

P

E

N

Fuel system schematic

1.3 Oil System Schematic

Oil pressure switch

Oil main gallery

Oil filter

Relief valve

Oil pump

Oil drain plug

Oil strainer

Oil system schematic

GENERAL

1 - 5

1.4 Cooling System Schematic

Radiator

Water pump

Water bypass valve

Thermostat

Cooling fan

Cooling system schematic

1.5 Inlet / Exhaust System Schematic

Exhaust gas

Intake air

Exhaust gas

(to muffler)

Air breather pipe
(positive crankcase
ventilation)

Blow-by gas

Intake air

(from air cleaner)

Inlet cover

Exhaust manifold

Inlet / exhaust system schematic

GENERAL

1 - 6

1.6 Engine Serial Number

The engine serial number is stamped on the top
face of the fuel injection pump bracket on the
right-hand side of the cylinder block.

1.7 Engine Model and Application Codes

(1) The engine model code is embossed on the side

of the fuel injection pump mount on the
right-hand side of the cylinder block.

(2) The engine model code consists of the following

alphanumerical digits.

Model coding

(Example) S

4 L 2

Type
(2 = Type 2)

Series
[L = bore size 78 mm (3.07 in.)]

No. of cylinders
(4 = 4 cylinders)

S = Sagamihara Machinery Works

Engine model code

Engine serial number location

Engine serial number

GENERAL

1 - 7

2. Specifications

Engine Type S3L S3L2 S4L S4L2

Type Water-cooled; 4-stroke cycle; Diesel powered
No. of cylinders 3 4
Combustion Swirl chamber type
Valve mechanism Overhead valve type

Cylinder bore×stroke mm (in.)

78×78.5

(3.07×3.09)

78×92

(3.07×3.62)

78×78.5

(3.07×3.09)

78×92

(3.07×3.62)

Total displacement l (U.S. gal)

1.125

(0.297)

1.318

(0.348)

1.500

(0.396)

1.758

(0.464)
Compression ratio 22.0 : 1
Fuel Diesel fuel (JIS K2204 Special 1 - 3)
Firing order 1-3-2 1-3-4-2
Direction of rotation Counterclockwise when viewed from the flywheel end

Overall length mm (in.) 536 (21.10) 620 (24.40)
Overall width mm (in.) 433 (17.04) 433 (17.04)

Dimensions

Overall height mm (in.) 572 (22.52) 572 (22.52)

General

Dry mass kg (lb) 135 (297.6) 155 (341.7)

Piston ring No. of rings

Compression ring :2

Oil ring (w/expander) : 1

Open BTDC 15°

Inlet valve

Close ABDC 41°
Open BBDC 54°

Va l ve
timing
(hot engine)

Exhaust valve

Close ATDC 10°

Engine mounting 4 mounts

Engine main parts

Starting method Starter

Type Bosch M
Manufacturer DENSO
Plunger
diameter

mm (in.)

φ5.5 (0.21)

MS retard
(crank angle)

8°

Injection
pump

Cam lift mm(in.) 15 (0.59)

Governor Governing method Centrifugal fly-weight type

Type Throttle nozzle
Manufacturer Bosch Automotive Systems Corporation
Spray angle mm (in.) 15°

Injection
nozzle

Opening
pressure

MPa

(kgf/cm

2

)

[psi]

14.22 to 15.00 (145 to 153)
[2062 to 2176]

Fuel system

Fuel filter Type Paper-element cartridge; Separate type w/ cock
Lubrication method Forced circulation (pressure feed by trochoid pump)

Grade CD Class (API Classification)

Engine oil

Capacity
(entire engine)

l (U.S. gal)

3.7 (1.0) 4.2 (1.1) 5.4 (1.4) 6.0 (1.6)

Type Gear pump

Oil pump

Displacement

l (U.S. gal)

/min

18 (4.8)

Type Piston valve

Relief valve

Opening
pressure

MPa

(kgf/cm

2

)

[psi]

0.35±0.05 (3.6±0.5)
[51±7]

Oil system

Oil filter Type Paper element (spin-on type)

GENERAL

1 - 8

Engine Type S3L S3L2 S4L S4L2

Cooling method Water-cooled, forced circulation
Capacity (engine proper)

l (U.S. gal)

1.8 (0.5) 2.5 (0.7)

Type Centrifugal pump

Water pu m p

Displacement

l (U.S. gal)

/min

30 (8.0) up (@ 2000 min

-1

engine speed)

Type Wax

Thermostat

Opening
temperature

℃ (°Ｆ)82±1.5 (179.6±2.7)

Type Pusher suction (PP fan)

Cooling system

Cooling fan

No. of blades / OD

mm (in.)

5 / 340 (13.39), 6 / 320 (12.6), 6 / 340 (13.39),

6 / 360 (14.17), 6 / 380 (14.96), 7 / 380 (14.96)

I

n

l

e

t

system

Air cleaner Type Paper element

Voltage - Polarity

12 V - Θ ground, 24 V - Θ ground

Type M001T68281, M008T70471A, M008T81071A
Manufacturer Mitsubishi Electric Corporation
Pinion
engagement

Pinion shift (reduction)

Output V-kW 12 V-1.7, 12 V-2.0, 24 V-3.2
No. of units 1

Starter

Reduction ratio

(pinion / ring gear)

13 / 120

Type 3-phase alternator w/ built-in IC regulator
Manufacturer Mitsubishi Electric Corporation
Output V-A 12-50, 24-25
Speed at which
rated voltage is
generated

min

-1

5000 (@ 13.5 V, 47 A), 5000 (@ 27.0 V, 22 A)

Alternator

Regulated voltage V

14.7±0.3 (12-50), 26.5±0.5 (24-25)

Type Sheathed plug

12 V plug 24 V plug

Glow plug

Rated voltage ­current

V- A

10.5-9.7

(30-second application)

22.5-5

(25-second application)

12 V-ETR 12 V-ETS 24 V-ETR 24 V-ETS Operating

voltage

V

8 or less 10 to 15 16 or less 20 to 30

Insulation resistance

100 MΩ or more at DC500 V

(at ordinary temperature and humidity)

Stroke mm (in.)

13.5±0.5 (0.53±0.01)

Electrical system

Stop
solenoid

Working
ambient
temperature

℃ (°Ｆ)

-40 to 120

(-40 to 248)

-30 to 120

(-22 to 248)

-40 to 120

(-40 to 248)

-30 to 120

(-22 to 248)

GENERAL

1 - 9

3. Disassembly / Reassembly Notes

This Service Manual specifies various procedures
recommended by Mitsubishi Heavy Industries, Ltd. for
servicing Mitsubishi diesel engines. These procedures
include, wherever appropriate, required special tools
and related safety precautions.
The instructions provided in this manual, however,
cannot fully guarantee safety as potential risks beyond
ordinary imagination are hidden everywhere.
When conduct any work, the following points should
also be observed in addition to the instructions this
manual.

3.1 Disassembly

(1) Use tools and equipment that are appropriate for

the work being carried out.

(2) Whenever necessary, use workbenches to work

on or sort parts out. Disassemble in accordance
with the disassembly sequence given in the
manual.

(3) As parts are disassembled, place them neatly in

the order of removal to eliminate missing parts
on reassembly.

(4) During disassembly, note the assembly marks.

Remember to respect these marks on reassembly.
Whenever appropriate, put additional assembly
marks to aid reassembly.

(5) Before and during disassembly as well as during

subsequent washing, carefully check for any
abnormality or other fault which otherwise may
likely remain unnoticed afterwards.

(6) Pay sufficient attention to ensure safety,

especially when lifting or carrying heavy
components and parts. (Use a jack or a chain
block as required.)

3.2 Reassembly

(1) Parts excluding oil seals, O-rings, rubber sheets,

etc. should be thoroughly washed in wash oil and
completely dried using compressed air.

(2) Use appropriate tools and equipment.
(3) Use good-quality oil and grease. Never fail to

apply oil, grease, sealant and adhesive to the
relevant locations if so instructed in the manual.

GENERAL

1 - 10

(4) Tighten hardware to the specified torque, if

provided in the manual. Be sure to use a torque
wrench.

(5) Gaskets, packing and O-rings should be replaced

with new parts unless specified otherwise.

1. Service Standards Table····································································· 1 -12

2. Tightening Torques Table···································································· 1 -16

2.1 Major Bolts and Nuts ··········································································· 1 -16

2.2 Standard Bolts and Nuts······································································· 1 -17

2.3 Standard Eyebolts··············································································· 1 -17

2.4 Standard Union Nuts ··········································································· 1 -18

2.5 Taper Bolts ························································································ 1 -18

3. Sealants List······················································································· 1 -19

SERVICE STANDARDS

SERVICE STANDARDS

1 - 12

1. Service Standards Table

Unit: mm (in.)

Group

Item

Nominal

value

Standard value Limit Remarks

Max. speed
(based on the rated speed)

2700

+30

-10

min-1

Min. speed

1000±25 min

-1

Compression pressure
(at 290 min

-1

)

2.9 MPa (30 kgf/cm

2

)
[421 psi]
or above

2.6 MPa

(27 kgf/cm

2

)

[377 psi]

or less

Both oil and coolant
temperatures at 20 to

30℃ (68 to 86°Ｆ)

Rated speed

0.29 to 0.39 MPa
(3.0 to 4.0 kgf/cm2)
[42.07 to 56.57 psi]

Engine oil

pressure

Low idle speed

0.098 MPa

(1.0 kgf/cm

2

)

[14.22 psi]

Oil temperature at

60 to 95℃ (140 to
194°Ｆ)

Inlet valve
open

BTDC 15

°

Inlet valve
closed

ABDC 41

°

Exhaust valve
open

BBDC 54

°

Valve timing [with
2 mm (0.079 in.)
clearance on the
valve side; cold
engine]

Exhaust valve
closed

ATD C 10

°

The theoretical valve
timing figures for
inspection vary from
the actual valve
timing.

Inlet valve 0.25 (0.01)

Valve clearance

Exhaust valve 0.25 (0.01)

Cold engine

Engine general

Fuel injection timing (BTDC)

17°

Rocker arm inner diameter

φ19

(0.749)

18.910 to 18.930

(0.7450 to 0.7458)

―

Rocker shaft diameter

φ19

(0.749)

18.880 to 18.898

(0.7438 to 0.7445)

―

Rocker

Arm-to-shaft clearance
(oil clearance)

0.012 to 0.050
(0.0004

to 0.0019)

0.200

(0.0079)

Replace rocker arm.

Inlet

φ6.6

(0.260)

6.565 to 6.580

(0.2586 to 0.2592)

6.500

(0.256)

Valve stem diameter

Exhaust

φ6.6

(0.260)

6.530 to 6.550

(0.2572 to 0.2580)

6.500

(0.256)

Inlet

φ6.6

(0.260)

6.600 to 6.615

(0.2600 to 0.2606)

Valve guide inner
diameter

Exhaust

φ6.6

(0.260)

6.600 to 6.615

(0.2600 to 0.2606)

Inlet

0.020 to 0.050

(0.0008 to 0.0020)

0.100

(0.004)

Va l ve

Valve stem-to-guide
clearance

Exhaust

0.050 to 0.085

(0.0020 to 0.0033)

0.150

(0.006)

Replace valve and
valve guide.

Valve seat angle

45

°

Valve head sinkage 0

0.25 to 0.75

(0.0098 to 0.0295)

1.5

(0.0591)

Valve seat width

1.6

(0.063)

1.30 to 1.80

(0.0512 to 0.0709)

2.5

(0.0985)

Valve head margin

1.5

(0.0591)

1.35 to 1.65

(0.0531 to 0.0650)

0.5

(0.0197)

Engine main parts

Valve seat and valve

Installed valve guide protrusion

10

(0.394)

9.5 to 10.5

(0.3743 to 0.4137)

―

Valve seat width

Val v e
seat
angle

Va l ve
head
mar

g

in

Valve head
sinka

g

e

SERVICE STANDARDS

1 - 13

Unit: mm (in.)

Group

Item

Nominal

value

Standard value Limit Remarks

Free length 47 (1.85) 46 (1.81)

Squareness

θ=2.0°
Δ=0.2

(0.0079)

Lf=47

(1.8518)

△= 0.5

(0.0197)
across the
entire length

Valve spring

Installed length / load

mm (in.)/N (kgf) [lbf]

39.0 (1.536)/
131 to 145

(13.3 to 14.7)

[29 to 33]

30.1 (1.185)/
279 to 309

(28.5 to 31.5)

[63 to 69]

-15 %

Push rod Bend

―

0.3 (0.011) Replace

Cylinder head

Bottom face
distortion

0.05 (0.002)
or less

0.10 (0.004) Correct

Cylinder block top face
distortion

0.05 (0.002)
or less

0.10 (0.004) Correct

Bore

φ78

(3.07)

78.0

+0.03
0

(3.07

+0.0012
0

)

78.2 (3.08) Bore or replace

Cylinder

Out of roundness

±0.01 (0.0004)

or less

―

STD

78.00
(3.07)

77.93 to 77.95

(3.070 to 3.071)

77.80

(3.065)

0.25 OS

78.25
(3.08)

78.18 to 78.20

(3.080 to 3.081)

78.05

(3.075)

Diameter

0.50 OS

78.50
(3.09)

78.43 to 78.45

(3.090 to 3.090)

78.30

(3.085)
Max. allowable variation in
weight among pistons on the
same engine

±5 g (0.177 oz)

or less

―

Piston pin diameter

φ23

(0.9062)

22.944 to 23.000

(0.9039 to 0.9062)

―

Piston pin-to-boss clearance

0.006 to 0.018

(0.0002 to 0.0007)

0.050

(0.002)

Piston

Piston-to-cylinder clearance

0.035 to 0.086

(0.0014 to 0.0034)

0.300

(0.012)

Bore or replace

No. 1 ring

0.09 to 0.11

(0.0035 to 0.0043)

0.300

(0.012)

No. 2 ring

0.07 to 0.11

(0.0028 to 0.0043)

0.200

(0.008)

Piston
ring-to-groove
clearance

Oil ring

0.03 to 0.07

(0.0012 to 0.0028)

0.200

(0.008)

Replace piston ring

No. 1 ring

0.15 to 0.30

(0.006 to 0.012)

No. 2 ring

0.15 to 0.35

(0.006 to 0.014)

Piston ring

Piston ring gap

Oil ring

0.20 to 0.40

(0.008 to 0.016)

1.50

(0.06)

Replace

Bend and twist

0.05/100

(0.002/3.940)

0.15/100

(0.006/3.940)

Engine main parts

Connecting

rod

End play

0.10 to 0.35

(0.004 to 0.014)

0.50

(0.020)

Replace connecting
rod

θ

SERVICE STANDARDS

1 - 14

Unit: mm (in.)

Group

Item

Nominal

value

Standard value Limit Remarks

Crank journal diameter (STD)

φ52

(2.0488)

51.985 to 52.000

(2.0482 to 2.0488)

―

Crank pin diameter

φ48

(1.8912)

47.950 to 47.964

(1.8892 to 1.8897)

―

Crankshaft bend 0.025 (0.0010)

0.050 (0.0020)

Correct or replace

Main bearings oil clearance

0.030 to 0.077

(0.0012 to 0.0030)

0.100

(0.0040)

Replace main

bearings
Connecting rod bearings oil
clearance

0.025 to 0.072

(0.0010 to 0.0028)

0.150

(0.0059)

Replace connecting

rod bearings

Crankshaft

End play

0.050 to 0.175

(0.0020 to 0.0069)

0.500

(0.0197)

Replace flanged No.

3 main bearings
Crank gear to idler gear
Idler gear to valve camshaft
gear
Idler gear to pump camshaft
gear

0.040 to 0.120

(0.0015 to 0.0047)

Valve camshaft gear to PTO
gear

0.080 to 0.190

(0.0032 to 0.0075)

Timing gear backlash

Pump camshaft gear to oil
pump gear

0.070 to 0.200

(0.0028 to 0.0079)

0.300

(0.0120)

Replace

Camshaft cam height
(including lobe)

35.720±0.1

(1.4073±0.0394)

34.720

(1.3679)

Replace

Fuel injection pump shaft cam
height (including lobe)

44±0.1

(1.7336±0.0039)

43

(1.6942)

Replace

Flywheel flatness

0.150 (0.0059)
or less

0.500

(0.0197)

Correct

Tappet-to-guide clearance

―

0.150

(0.0059)

Replace tappet

Camshaft journal-to-bushing
clearance

0.050 to 0.125

(0.0020 to 0.0049)

0.150

(0.0059)

Replace bushing

Engine main parts

Idler gear-to-shaft clearance

0.020 to 0.070

(0.0008 to 0.0028)

0.200

(0.0079)

Replace idler gear or
idler shaft

Fuel system

Injection valve opening pressure

MPa (kgf/cm

2

) [psi]

14.22
(145)

[2062]

14.22 to 15.00
(145 to 153)

[2062 to 2176]

―

Adjust with washer

Relief valve opening pressure

MPa (kgf/cm

2

) [psi]

0.35±0.05
(3.5±0.5)
[50±7.2]

―

Replace

Oil system

Oil pressure switch closing pressure

MPa (kgf/cm

2

) [psi]

0.05±0.01
(0.5±0.1)

[7±1.4]

―

Replace

Valve opening
temperature

82±1.5℃

(179.6±2.7°Ｆ)

―

Thermostat

8 mm (0.32 in.)
valve lift
temperature

95℃

(203°Ｆ)

―

Replace

Thermoswitch

At 111±3.5℃
(231.8±6.3°Ｆ)

30 MΩ

[when dipped in oil of

105℃ (221°Ｆ)]

―

Replace

Cooling system

Fan belt deflection {when pressed
with a force of approx. 98 N (10
kgf) [22] between crankshaft and
alternator pulleys and between
crankshaft and fan pulleys}

10 to 12

(0.4 to 0.5)

―

Replace

SERVICE STANDARDS

1 - 15

Unit: mm (in.)

Group

Item

Nominal

value

Standard value Limit Remarks

Paper-element type air
cleaner

Clean every 100 hours

Replace every

500 hours

I

n

l

e

t

an

d

ex

h

aus

t

s

y

stems

Inlet / exhaust manifold
mounting face distortion

―

0.15 (0.006)
or less

Grind or
replace

Pinion gap

0.5 to 2.0

(0.02 to 0.08)

―

Adjust with
packing

M001T68281 M008T70471A M008T81071A

Term inal
voltage

11 V 11 V 23 V

―

Current

110 A

or less

130 A

or less

80 A

or less

―

No-load
character­istics

Rotation
speed

2400
min

-1

3600
min-1

3000

min-1

―

Inspect

M001T68281

M008T70471A,

M008T81071A

Brush length

16.5

(0.65)

18.0

(0.71)

10.0

(0.39)

11.0

(0.43)

Replace

Brush spring load

17.5 to

23.7 N

(1.78 to

2.41 kgf)

[3.9 to 5.3

lbf]

29.4 to 39.2 N

(3.0 to 4.0 kgf)

[6.6 to 8.8 lbf]

6.90 N

(0.70 kgf)

[1.6 lbf]

13.7 N

(1.40 kgf)

[3.1 lbf]

Replace

Commutator radial
runout

0.05

(0.002)

0.03

(0.001)

0.10

(0.004)

Correct or
replace

Commutator diameter

29.4

(1.16)

32.0

(1.26)

28.8

(1.13)

31.4

(1.24)

Replace

Starter

Mica undercutting
depth

0.5

(0.02)

0.2

(0.01)

Correct

A007T02071C A007TA8571

―

IC regulator
controlled voltage

[at 20℃ (68°Ｆ)]

14.7±0.3 V 28.5±0.5 V

Term inal
voltage

13.5 V 27.0 V

―

2500
min

-1

or
less

Current 32 A or above 18 A or above

―

Term inal
voltage

13.5 V 27.0 V

―

O

utput c

h

aracter

i

st

i

cs

(

when hot

)

5000
min

-1

or
less

Current 47 A or above 22 A or above

―

Alternator

Brush length 18.5 (0.73) 5.0 (0.20) Replace
Clearance between stop
solenoid plunger and rack

0.15 to 0.20

(0.006 to 0.008)

Correct

Electrical system

Glow plug resistance 0.55 Ω

―

Replace

SERVICE STANDARDS

1 - 16

2. Tightening Torques Table

2.1 Major Bolts and Nuts

Tightening torque

Fittings

Thread

diameter

×pitch

(mm)

N･m kgf･m lbf･ft

Remarks

Engine proper

Cylinder head bolt

M10×1.75

83.4 to 93.2 8.5 to 9.5 61.5 to 68.7

Rocker cover bolt

M8×1.25

9.81 to 12.7 1.0 to 1.3 7.2 to 9.4

Rocker shaft bracket bolt

M8×1.25

9.81 to 19.6 1.0 to 2.0 7.2 to 14.5

Thrust plate bolt

M8×1.25

9.8 to 11.8 1.0 to 1.2 7.2 to 8.7

Main bearing cap bolt

M10×1.25

49.0 to 53.9 5.0 to 5.5 36.2 to 39.8

Connecting rod cap nut

M9×1.0

32.4 to 37.3 3.3 to 3.8 23.9 to 27.5

Flywheel bolt

M12×1.25

127 to 137 13.0 to 14.0 94.0 to 101.3

Crankshaft pulley nut

M18×1.5

147 to 196 15.0 to 20.0 108.5 to 144.6

Rear plate mounting bolt

M12×1.25

53.9 to 73.5 5.5 to 7.5 39.8 to 54.2 Equivalent to 7T

Fuel system

Hollow screw
(fuel injection pump)

M14×1.5

19.6 to 24.5 2.0 to 2.5 14.5 to 18.1

Delivery valve holder
(fuel injection pump)

―

39.2 to 49.0 4.0 to 5.0 28.9 to 36.1

Air bleeder plug
(fuel injection pump)

M8×1.25

9.81 to 13.7 1.0 to 1.4 7.2 to 10.1

Nozzle retaining nut

IDI

M16×0.75

34.3 to 39.2 3.5 to 4.0 25.3 to 28.9

Nozzle holder IDI

M20×1.5

49.0 to 58.8 5.0 to 6.0 36.2 to 43.4

Fuel injection pipe nut

M12×1.5

24.5 to 34.3 2.5 to 3.5 18.1 to 25.3

Fuel leak-off pipe nut

M12×1.5

20.6 to 24.5 2.1 to 2.5 15.2 to 18.1

Sliding sleeve shaft

M10×1.25

29.4 to 41.2 3.0 to 4.2 21.7 to 30.4

Torque spring set special nut

M12×1.0

14.7 to 24.5 1.5 to 2.5 10.8 to 18.1

Oil system

Oil relief valve

M22×1.5

44.1 to 53.9 4.5 to 5.5 32.5 to 39.8

Oil pan drain plug

M14×1.5

34.3 to 44.1 3.5 to 4.5 25.3 to 32.5

Oil filter

M20×1.5

10.8 to 12.7 1.1 to 1.3 8.0 to 9.4

Oil pressure switch PT1/8 7.85 to 11.8 0.8 to 1.2 5.8 to 8.7

Oil pan mounting bolt

M8×1.25

9.80 to 12.7 1.0 to 1.3 7.2 to 9.4 Equivalent to 4T

Oil strainer nut

M16×1.5

24.5 to 29.4 2.5 to 3.0 18.1 to 21.7

Cooling system

Thermoswitch

M16×1.5

18.6 to 26.5 1.9 to 2.7 13.7 to 19.6

Thermostat cover bolt

M8×1.25

16 to 20 1.6 to 2.0 11.8 to 14.8

Thermo case bolt

M16×1.5

39.2 to 49.0 4.0 to 5.0 28.9 to 36.1

Inlet and exhaust systems

Inlet cover bolt

M8×1.25

14.7 to 21.6 1.5 to 2.2 10.8 to 15.9

Exhaust manifold bolt

M8×1.25

14.7 to 21.6 1.5 to 2.2 10.8 to 15.9

Electrical system

Starter terminal B

M8×1.25

9.81 to 11.8 1.0 to 1.2 7.2 to 8.7

Stop solenoid fixing nut

M30×1.5

39.2 to 49.0 4.0 to 5.0 28.9 to 36.1

Stop solenoid blind plug

M30×1.5

39.2 to 49.0 4.0 to 5.0 28.9 to 36.1

Glow plug

M10×1.25

14.7 to 19.6 1.5 to 2.0 10.8 to 14.5

SERVICE STANDARDS

1 - 17

2.2 Standard Bolts and Nuts

4T 7T

Thread

diameter

×pitch (mm)

N･m kgf･m lbf･ft N･m kgf･m lbf･ft

M6×1.0

2.94 to 4.90 0.3 to 0.5 2.2 to 3.6 7.85 to 9.80 0.8 to 1.0 5.8 to 7.2

M8×1.25

9.80 to 12.7 1.0 to 1.3 7.2 to 9.4 14.7 to 21.6 1.5 to 2.2 10.8 to 15.9

M10×1.25

17.7 to 24.5 1.8 to 2.5 0.7 to 1.0 29.4 to 41.2 3.0 to 4.2 21.7 to 30.4

M12×1.25

29.4 to 41.2 3.0 to 4.2 21.7 to 30.4 53.9 to 73.5 5.5 to 7.5 39.8 to 54.2

Note: (a) The above table shows the tightening torques for standard bolts and nuts.
(b) The values in the table apply when tightened together with spring washers.

(c) The above table shows standard values, for which a tolerance of ±10% is allowed.

(d) Unless otherwise specified, standard bolts and nuts should be tightened to the torques in the table.
(e) Do not apply oil to threaded portions (Tighten under dry conditions).

2.3 Standard Eyebolts

Property class

Thread diameter

×pitch (mm)

N･m kgf･m lbf･ft

M8×1.25 8±1 0.8±0.1

5.9±0.7

M10×1.25 15±2 1.5±0.2

11.1±1.5

M12×1.25 25±3 2.5±0.3

18.4±2.2

M14×1.5 34±4 3.5±0.4

25.1±3.0

M16×1.5 44±5 4.5±0.5

32.5±3.7

M18×1.5 74±5 7.5±0.5

54.6±3.7

M20×1.5 98±10 10.0±1.0

72.3±7.4

M24×1.5 147±15 15.0±1.5

108.4±10.8

M27×1.5 226±20 23.0±2.0

166.7±14.8

(Dry conditions)

SERVICE STANDARDS

1 - 18

2.4 Standard Union Nuts

Nominal
diameter

Cap nut size

N･m kgf･m lbf･ft

63

M14×1.5

39 4 28.8

80

M16×1.5

49 5 36.1

100

M20×1.5

78 8 57.5

120

M22×1.5

98 10 72.3

150

M27×1.5

157 16 115.8

180

M30×1.5

196 20 144.6

200

M30×1.5

196 20 144.6

220

M33×1.5

245 25 180.7

254

M36×1.5

294 30 216.8

(Dry conditions)

2.5 Taper Bolts

Tightening into aluminum Tightening into iron

Size

N･m kgf･m lbf･ft N･m kgf･m lbf･ft

NPTF1/16 4.90 to 7.85 0.5 to 0.8 3.6 to 5.8 7.85 to 11.8 0.8 to 1.2 5.8 to 8.7

PT1/8 7.85 to 11.8 0.8 to 1.2 5.8 to 8.7 14.7 to 21.6 1.5 to 2.2 10.8 to 15.9

PT1/4, NPTF1/4 19.6 to 29.4 2.0 to 3.0 14.5 to 21.7 34.3 to 44.1 3.5 to 4.5 25.3 to 32.5

PT3/8 ― ― ― 53.9 to 73.5 5.5 to 7.5 39.8 to 54.2

SERVICE STANDARDS

1 - 19

3. Sealants List

Sealing item Sealant

Mating

component

Applied location

Stop solenoid ThreeBond 1212 Governor case

Water drain joint

Oil pressure switch

ThreeBond 1102 Block

Threaded part

Torque spring set ThreeBond 1212 Governor case

Threaded portion

Cylinder block

Cylinder head

Sealing cap

Cylinder head,

Cylinder block

Expansion plug

Holes in the cylinder
head and block

Press - fit part

Oil level gauge guide

ThreeBond 1102

Cylinder block

Side seal

Cylinder block,

Main bearing cap

Outer periphery

Main bearing cap
(front and rear)

ThreeBond 1212

Contact faces with the
cylinder block

Other

Oil pan

ThreeBond

1207C

Cylinder block

Oil pan sealing face

SERVICE STANDARDS

1 - 20

1. General Tools ····················································································· 1 -22

2. Special Tools······················································································· 1 -23

TOOLS LIST

TOOLS LIST

1 - 22

1. General Tools

No. Description Part number Remarks

―

Tool set MM413-900

Consists of items ① to ⑤

①

Spanner MK96008010

Width across flats [8×10 mm (0.31×0.39 in.)]

②

Spanner MK96012014

Width across flats [12×14 mm (0.47×0.55 in.)]

③

Spanner MK96017019

Width across flats [17×19 mm (0.67×0.75 in.)]

④

Screwdriver MM300110 (-)

⑤

Tool bag MM300783

TOOLS LIST

1 - 23

2. Special Tools

Description Part number Shape Application

Piston Pin
Setting T ool

31A91-00100

Piston pin
removal / installation

Camshaft Bushing
Installer

ST332340

Punching / press-fitting of
front camshaft bushing

Compression Gauge
Adapter

ST332270

Compression measuring

Oil Pressure Switch
Socket Wrench
(26)

MD998054

Oil pressure switch
removal / installation

Piston Ring Pliers 31391-12900

Piston ring
removal / installation

TOOLS LIST

1 - 24

1. Identifying the Timing for Overhaul······················································ 1-26

2. Measuring the Compression Pressure················································1-27

OVERHAUL TIMING

OVERHAUL TIMING

1 - 26

1. Identifying the Timing for Overhaul

Generally, when the compression pressure has dropped below the specified value, overhaul of the engine
needs to be considered. Other parameters should also be considered in making the decision as to whether or
not to overhaul the engine, such as engine oil consumption and blow-by gas volume.

Some of the phenomena that may suggest, but are not necessarily the criteria for, the need to overhaul the
engine include reduced power, increased fuel consumption, oil pressure drop, difficulty in starting and higher
noise level.

More specifically, reduction in compression pressure creates various types of phenomena in various
combinations, and this is why it is difficult to make a correct decision. Typical phenomena include:

(a) Reduced power
(b) Increased fuel consumption
(c) Increased engine oil consumption
(d) Increased blow-by gas through the breather due to worn parts such as cylinder liners and pistons
(e) Increased blow-by gas due to poor seating of inlet / exhaust valves
(f) Poor starting
(g) Increased noise levels of various engine parts
(h) Abnormal color of exhaust gas after warm-up

Some of those listed above are directly related to the deterioration of the engine and some are not.

Items (b) and (f) are heavily influenced by fuel injection pump displacement, fuel injection timing, wearing
of plungers, nozzle conditions, and conditions of electrical equipment such as battery and starter.

The most reliable criterion for engine overhaul is reduced compression pressure due to the wearing of
cylinder liners and pistons [item (d)]. This should be combined with other items for comprehensive review
to reach a rational conclusion.

OVERHAUL TIMING

1 - 27

2. Measuring the Compression Pressure

(1) Move the control lever to STOP position.
(2) Remove the glow plugs from all cylinders.

Install the special tool Compression Gauge
Adapter and a compression gauge onto the
cylinder being measured.

Special tool Part number

Compression Gauge Adapter ST332270

(3) While cranking the engine with the starter, read

the compression gauge. Note the reading at
which the gauge needle stabilizes.

(4) If the measured value is at or below the limit,

overhaul the engine.

(a) Measure all cylinders for compression

pressure. Do not measure only one
cylinder and make assumption about the
other cylinders as this will lead to a wrong
conclusion.

(b) Compression pressure varies depending

on the engine speed. Keep the specified
engine speed when measuring the
compression pressure.

Standard value Limit

Engine speed 290 min-1
Compression

pressure

2.9 MPa

(30 kgf/cm

2

)

[421 psi]

2.6 MPa

(27 kgf/cm2)

[377 psi]
Tolerable
difference
between
cylinders

0.29 MPa

(3.0 kgf/cm

2

)

[42 psi]

or less

It is important to regularly check the
compression pressure so that you can tell the
difference.
・ New or overhauled engines have slightly

higher compression pressure.

・ The compression pressure settles to the

standard value as the piston rings and
valve seats fit in.

・ As wear progresses further, the

compression pressure drops.

Compression
gauge adapter

Compression
gauge

Measuring the compression pressure

OVERHAUL TIMING

1 - 28

1. Preparations························································································ 1-30

1.1 Removing the Electric Wiring ································································· 1-30

1.2 Draining the Coolant············································································· 1-30

1.3 Draining the Engine Oil ········································································· 1-30

REMOVAL PREPARATIONS

REMOVAL PREPARATIONS

1 - 30

1. Preparations

1.1 Removing the Electric Wiring

Remove the wiring harnesses from the following
equipment.
Before removal, attach mating tags etc. onto the
terminals to aid reassembly.

・Starter
・Switches

1.2 Draining the Coolant

Loosen the coolant drain plug on the right-hand
side face of the cylinder block to drain coolant
from the engine.

1.3 Draining the Engine Oil

Remove the engine oil drain plug from the oil
pan to drain the engine oil.
Install and tighten the drain plug to the specified
torque.
Oil pan capacity: 3.7 to 6.0 l

(1.0 to 1.6 U.S. gal)

Do not touch the engine oil which may be
extremely hot as it can cause burns.

Removing the electric wiring

Coolant drain cock

Drain plug on the oil pan

Starter

Starter
wiring

Retaining bol

t

Drain plug

34.3 to 44.1N㨯m
(3.5 to 4.5kgf㨯m)
[25.3 to 32.5 lbf㨯ft]

Drain piug

Tightening torqe:

1. Cylinder Head, Valve Mechanism························································ 2 - 2

1.1 Removing the rocker shaft assembly······················································· 2 - 3

1.2 Disassembling the rocker shaft assembly················································· 2 - 3

1.3 Removing the cylinder head bolts ··························································· 2 - 3

1.4 Removing the cylinder head assembly····················································· 2 - 4

1.5 Removing the valves and valve springs ··················································· 2 - 4

1.6 Removing the valve stem seals ······························································ 2 - 4

2. Flywheel, Timing Gear, Camshaft························································ 2 - 5

2.1 Removing the flywheel·········································································· 2 - 7

2.2 Removing the flywheel housing ······························································ 2 - 7

2.3 Removing the rear plate········································································ 2 - 8

2.4 Removing the oil seal case···································································· 2 - 8

2.5 Removing the tappets··········································································· 2 - 8

2.6 Removing the crankshaft pulley······························································ 2 - 8

2.7 Removing the timing gear case ······························································ 2 - 9

2.8 Measuring the timing gear backlash ························································ 2 - 9

2.9 Removing the idler gear······································································· 2 -10

2.10 Removing the camshaft········································································ 2 -10

2.11 Removing the fuel injection pump camshaft············································· 2 -10

2.12 Separating the gears from the shafts (as required)···································· 2 -10

2.13 Removing the oil pump ·········································································2 -11

2.14 Removing the front plate ······································································· 2 -11

3. Cylinder Block, Crankshaft, Pistons, Oil Pan······································ 2 -12

3.1 Removing the oil pan··········································································· 2 -13

3.2 Removing the oil strainer······································································ 2 -13

3.3 Removing the connecting rod caps ························································ 2 -13

3.4 Removing the pistons ·········································································· 2 -14

3.5 Measuring the crankshaft end play························································· 2 -14

3.6 Removing the main bearing caps··························································· 2 -14

3.7 Removing the crankshaft······································································ 2 -14

3.8 Separating the piston from the connecting rod·········································· 2 -15

ENGINE MAIN PARTS - DISASSEMBLY

ENGINE MAIN PARTS - DISASSEMBLY

2 - 2

1. Cylinder Head, Valve Mechanism

Worn rocker shaft,
Clogged oil hole

Spring fatigue

Dent, Wear

Stepped wear, Damage

Wear,
Valve face contact

End face wear, damage

Bend

Valve seat contact,
damage, wear

Bottom face distortion

Valve guide wear, damage

Cracks, Damage, Coolant leakage,
Oil leakage, Scale formation,
Gasket, Carbon deposit

Damaged threads

Clogged oil hole

Wear

Spring fatigue,
damage

Disassembly of cylinder head and valve mechanism

<Disassembly sequence>

① Rocker cover
② Rocker shaft assembly
③ Push rod
④ Cylinder head bolt

⑤ Cylinder head
⑥ Cylinder head gasket
⑦ Valve cap
⑧ Valve lock

⑨ Retainer
⑩ Valve
⑪ Valve spring
⑫ Valve stem seal

ENGINE MAIN PARTS - DISASSEMBLY

2 - 3

1.1 Removing the rocker shaft assembly

(1) Loosen the rocker stay bolts. Remove the

rocker shaft assembly together with the rocker
stay bolts.

(2) Remove the valve caps.
(3) Keep the rocker shaft assembly with the rocker

stay bolts.

1.2 Disassembling the rocker shaft
assembly

In the course of disassembly, place removed
valve rockers as well as the other parts neatly in
the order of disassembly so that they can be
reassembled back onto their original locations.
Doing so, original clearances between the valve
rockers and the rocker shaft is restored upon
reassembly.

1.3 Removing the cylinder head bolts

Loosen the cylinder head bolts in the order of
the numbers illustrated. Do not loosen one bolt
completely before moving to the next bolt.
Loosen the bolts in a couple of steps.

Note: Before removing the cylinder head bolts,

check the cylinder head components for any
fault. If faulty, check the bolts for tighteness
with a torque wrench.

Removing the rocker shaft assembly

Disassembling the rocker shaft assembly

Tightening order for cylinder head bolts

1

79

6

4

3

5

10 8

2

12

14

13

11

Front of engine

11

1

7

9

6

4

3

5

10

8

2

S4L,
S4L2

S3L,S3L2

ENGINE MAIN PARTS - DISASSEMBLY

2 - 4

1.4 Removing the cylinder head assembly

Remove the cylinder head assembly by lifting it
straight up.

Note: If the bonding of the cylinder head gasket

prevents the head assembly from being
separated from the cylinder block, tap the
cylinder head side face on a relatively thick
portion with a plastic hammer.

1.5 Removing the valves and valve springs

(1) Remove the valve caps and locks by

compressing the springs using a valve lifter.

(2) Remove the retainers, valve springs and valves.
Note: If the valves are reusable, mark them so that

they can be reassembled back onto their original
locations. This will ensure that the mated pairs
of valves and their seats are maintained.

1.6 Removing the valve stem seals

Remove the valve stem seals by holding each of
them with a pair of pliers.

Note: Replace the old valve stem seals with new parts

upon reassembly.

Removing the cylinder head assembly

Removing the valve spring

Removing the valve stem seal

ENGINE MAIN PARTS - DISASSEMBLY

2 - 5

2. Flywheel, Timing Gear, Camshaft

Flywheel end of engine

Frictional surface streak,
stepped wear, cracks;
Ring gear damage,
abnormal wear

Oil seal wear, damage,
deterioration

Cracks, Damage

Replace: Gasket

Disassembly of flywheel

<Disassembly sequence>

① Flywheel
② Flywheel housing

③ Rear plate
④ Oil seal case, Oil seal

ENGINE MAIN PARTS - DISASSEMBLY

2 - 6

Timing gear end of engine

Wear, damage of each gear

Ball bearing wear, noise

Cam lobe wear, damage

Wear on tappet contact face with cam

Speedometer driven gear damage

Cam lobe wear, Bent shaft

Cracks, Damage, Distortion

Crankshaft pulley groove wear, damage

Replace: Gasket

Replace: Gasket

Disassembly of timing gear and camshaft

<Disassembly sequence>

⑤ Tappet
⑥ PTO gear
⑦ Crankshaft pulley
⑧ Timing gear case
⑨ Idler gear
⑩ Camshaft gear
⑪ Thrust plate
⑫ Camshaft

(Remove ⑩ to ⑫ as an assembly.)

⑬ Fuel injection pump camshaft gear
⑭ Ball bearing
⑮ Fuel injection pump camshaft

(Remove ⑬ to ⑮ as an assembly.)
⑯ Oil pump
⑰ Front plate

ENGINE MAIN PARTS - DISASSEMBLY

2 - 7

2.1 Removing the flywheel

(1) Have an assistant lock the fly wheel pulley using

a wrench or other similar tool to prevent the
flywheel from rotating.

(2) Remove one of the flywheel retaining bolts.

The person who locks the crankshaft pulley
should do so with extreme care. Each
worker should pay attention to the safety of
the other.

(3) Install a safety stud (M12×1.25) into the hole

from which the retaining bolt has just been
removed. With the stud installed, remove the
remaining flywheel retaining bolts.

(4) While holding the flywheel with both hands,

rock the flywheel towards you and away to pull
it out straight towards you.

(a) When pulling off the flywheel, be careful not

to cut your hands with the ring gear.

(b) Be careful not to damage the flywheel by

dropping it or bumping it against hard
objects.

(c) The ring gear has been shrink-fit onto the

flywheel. Do not attempt to remove the
ring gear unless it is faulty.

2.2 Removing the flywheel housing

Remove the flywheel housing retaining bolts.
Remove the flywheel housing.

Locking the flywheel

Removing the flywheel

Removing the flywheel housing

Locking the flywheel with a wrench etc.

Safety stud

ENGINE MAIN PARTS - DISASSEMBLY

2 - 8

2.3 Removing the rear plate

The rear plate has been located into position
with knock pins. Therefore, the plate needs to
be removed by pulling it straight towards you.

2.4 Removing the oil seal case

Remove the oil seal case retaining bolts. Then,
ply away the case from the cylinder block using
a screwdriver or other similar tool.

When removing the oil seal case, be careful
not to damage the oil seal.

2.5 Removing the tappets

While holding the push rods, remove the tappets
from the cylinder block.

Note: The camshaft should not be removed before

removing the tappets. Otherwise, the tappets
will drop into the oil pan.

2.6 Removing the crankshaft pulley

(1) Lock the crankshaft so that it will not rotate.

To rock the camshaft, install two safety studs
(M12×1.25) into the threaded holes at the rear

end of the crankshaft and then place a bar
between the studs.

(2) Remove the crankshaft pulley.

While trying to remove the crankshaft pulley,
the bar may dislodge from the studs. Pay
sufficient attention to ensure safety.

Removing the rear plate

Removing the oil seal case

Removing the tappet

Removing the crankshaft pulley

Tappet

Push rod

Lock the crankshaft.

Crankshaft
pulley

ENGINE MAIN PARTS - DISASSEMBLY

2 - 9

2.7 Removing the timing gear case

Remove the timing gear case retaining bolts.
Then, remove the timing gear case.

The front plate is bolted in place separately
from the timing gear case. Do not attempt to
tap away the front plate together with the
timing gear case.

2.8 Measuring the timing gear backlash

Measure the backlash between the gears and use
the measurements as references upon
reassembly.
If any of the measured values exceeds the limit,
replace all gears unless otherwise specified.

Unit: mm (in.)

Standard value Limit

Crank gear - idler
gear
Idler gear - valve
camshaft gear
Idler gear - pump
camshaft gear

0.04 to 0.12

(0.0016 to 0.0047)

Valve camshaft
gear - PTO gear

0.08 to 0.19

(0.0031 to 0.0075)

Timing gear backlash

Pump camshaft
gear - oil pump
gear

0.07 to 0.20

(0.0028 to 0.0079)

0.30

(0.0118)

Removing the timing gear case

Front plate retaining bolts

Measuring the timing gear backlash

ENGINE MAIN PARTS - DISASSEMBLY

2 - 10

2.9 Removing the idler gear

Remove the idler gear by sliding it out along the
helical teeth.

2.10 Removing the camshaft

(1) Remove the thrust plate retaining bolts.
(2) Gently pull out the camshaft, taking care not to

damage it.

When pulling out the camshaft, pay attention
to the cams as they tend to be caught by the
surrounding parts.

2.1 1 Removing the fuel injection pump
camshaft

(1) Remove the stopper bolt (one place).

(2) Using a copper rod or other similar tool, tap the

rear end of the fuel injection pump camshaft.
Then, pull it out to the front of the engine.

2.12 Separating the gears from the shafts (as
required)

Using a hydraulic jack, remove the camshaft
gear and the fuel injection pump camshaft gear
from the respective shafts.

Removing the idler gear

Pulling out the camshaft

Removing the pump camshaft stopper bolt

Removing the pump camshaft

ENGINE MAIN PARTS - DISASSEMBLY

2 - 11

2.13 Removing the oil pump

Remove the oil pump retaining bolts. Then,
remove the oil pump from the cylinder block.

2.14 Removing the front plate

Remove the four front plate retaining bolts.
Then, gently tap the plate with a plastic hammer
to remove the gasket.

Removing the oil pump

Removing the front plate

ENGINE MAIN PARTS - DISASSEMBLY

2 - 12

3. Cylinder Block, Crankshaft, Pistons, Oil Pan

Cylinder damage,
stepped wear

Top face distortion

Connecting rod bend,
twist,
Big end thrust clearance

Crank journal/pin damage,
uneven wear, cracks, bend,
Clogged oil hole

The main bearings may be seized
due to poor oil maintenance etc.
In that case, the crankshaft must
be replaced.

Caution

Damaged plugs and
knock pins

Dirty or clogged oil and
water galleries

Damaged crankshaft
gear teeth

Seizing

Scoring

Pealing

Piston ring wear, damage,
Ring gap clearance

Piston wear, seizure,
streak,
Ring groove wear

Replace: Side seal

Disassembly of cylinder block, crankshaft, pistons and oil pan

<Disassembly sequence>

① Oil pan
② Oil strainer
③ Connecting rod cap
④ Connecting rod bearing (lower)
⑤ Connecting rod
⑥ Piston pin
⑦ No. 1 ring
⑧ No. 2 ring

⑩ Piston

(Remove ⑤ to ⑩ as an assembly.)
⑪ Connecting rod bearing (upper)
⑫ Main bearing cap
⑬ Main bearing (lower)
⑭ Crankshaft
⑮ Main bearing (upper)
⑯ Cylinder block

⑨ Oil ring

Note: If the crankcase is to be replaced, carefully remove the relief valve and other parts from the old

crankcase for reassembly onto the new crankcase.

ENGINE MAIN PARTS - DISASSEMBLY

2 - 13

3.1 Removing the oil pan

(1) Turn the engine upside down.
(2) Remove the oil pan by tapping it on the bottom

corners with a plastic hammer.

Do not insert a chisel or a screwdriver
between the oil pan and the cylinder block to
remove the oil pan. Otherwise, the oil pan
flange face will be deformed.

3.2 Removing the oil strainer

Loosen the nut to remove the oil strainer.

3.3 Removing the connecting rod caps

(1) Place the cylinder block on the side.
(2) Mark the cylinder numbers on the connecting

rods and caps to ensure that they will be
reassembled in original pairs.

(3) Remove the connecting rod caps.

Removing the oil pan

Removing the oil strainer

Removing the connecting rod caps

ENGINE MAIN PARTS - DISASSEMBLY

2 - 14

3.4 Removing the pistons

(1) Rotate the crankshaft to place the piston being

removed at the top dead center.

(2) Using a wooden piece such as the stem of a

hammer, push the piston and connecting rod
assembly on the mating face with the connecting
rod cap to remove the assembly from the
cylinder block.

3.5 Measuring the crankshaft end play

With a dial gauge installed onto the end of the
crankshaft, measure the shaft end play.
If the measured value exceeds the limit, replace
the flanged No. 3 bearing.

Unit: mm (in.)

Standard value Limit

Crankshaft end
play

0.050 to 0.175

(0.0020 to 0.0069)

0.500

(0.0197)

3.6 Removing the main bearing caps

(1) Place the engine so that the cylinder block

mating surface with the oil pan faces upwards.

(2) Loosen the main bearing cap bolts. Then,

remove the caps.

(3) On the front and rear main bearing caps, remove

these using a sliding hammer.

3.7 Removing the crankshaft

(1) Remove the crankshaft by slowly lifting it

straight up.

When lifting the crankshaft, take care not to
damage the main bearings.

(2) The main bearings may fall down, making it not

possible to identify their original locations.
Once the crankshaft is removed, place the main
bearings neatly and in the original pairs so that
they can be reassembled back onto their original
locations.

Removing the piston

Measuring the crankshaft end play

Removing the main bearing cap

Removing the crankshaft

ENGINE MAIN PARTS - DISASSEMBLY

2 - 15

3.8 Separating the piston from the
connecting rod

(1) Remove the piston pin using the special tool

Piston Pin Setting Tool.

Special tool Part number

Piston Pin Setting Tool 31A91-00100

(2) Insert the tool’s push rod into th e piston pin hole.

Using a press against the push rod, extract the
piston pin.

(3) Use the Piston Pin Setting Tool again to

reassemble the piston and the connecting rod.

Do not try to remove the piston pin by tapping
it.
If the piston has been agglutinated and
requires a great force to remove, replace it
with a new part.

Piston Pin Setting Tool

Removing the piston pin (1)

Removing the piston pin (2)

Push rod

Connecting rod

Identification mark

Tool body

Piston pin

Piston
arrow mark

Piston

ENGINE MAIN PARTS - DISASSEMBLY

2 - 16

1. Cylinder Head, Valve Mechanism······················································· 2 -18

1.1 Measuring the cylinder head bottom face distortion··································· 2 -18

1.2 Measuring the rocker arm bore and the rocker shaft diameter····················· 2 -18

1.3 Measuring the valve spring for squareness and free length ························ 2 -18

1.4 Measuring the push rod for bend ··························································· 2 -19

1.5 Measuring the valve stem diameter························································ 2 -19

1.6 Measuring the clearance between the valve stem and guide······················· 2 -19

1.7 Replacing the valve guide····································································· 2 -20

1.8 Inspecting the valve face······································································ 2 -20

1.9 Correcting the valve face······································································ 2 -21

1.10 Correcting the valve seat······································································ 2 -21

1.11 Lapping the valve face against the valve seat ·········································· 2 -22

1.12 Replacing the combustion jets······························································· 2 -22

2. Flywheel, Timing Gear, Camshaft······················································· 2 -23

2.1 Measuring the flywheel flatness····························································· 2 -23

2.2 Replacing the ring gear········································································ 2 -23

2.3 Measuring the timing gear backlash ······················································· 2 -23

2.4 Measuring the clearance between the idler gear and the idler shaft·············· 2 -24

2.5 Replacing the idler shaft······································································· 2 -24

2.6 Measuring the clearance between the camshaft journal and the bushing ······ 2 -24

2.7 Extracting the camshaft bushing···························································· 2 -25

2.8 Press-fitting the camshaft bushing ························································· 2 -25

2.9 Measuring the camshaft cam height······················································· 2 -25

2.10 Measuring the fuel injection pump shaft cam height ·································· 2 -25

2.11 Inspecting the cam-to-tappet contact······················································ 2 -26

2.12 Measuring the clearance between the tappet and the tappet guide ·············· 2 -26

3. Cylinder Block, Crankshaft, Pistons, Oil Pan······································ 2 -27

3.1 Measuring the piston diameter ······························································ 2 -27

3.2 Measuring the clearance between the piston ring and the ring groove·········· 2 -27

3.3 Measuring the piston ring gap ······························································· 2 -27

3.4 Measuring the clearance between the piston pin and the pin boss··············· 2 -28

3.5 Measuring the connecting rod bend and twist··········································· 2 -28

3.6 Measuring the connecting rod end play··················································· 2 -29

3.7 Inspecting the oil clearance for connecting rod bearings ···························· 2 -29

3.8 Inspecting the main bearings oil clearance ·············································· 2 -30

3.9 Measuring the crankshaft for bend························································· 2 -31

3.10 Removing the crankshaft gear······························································· 2 -31

3.11 Installing the crankshaft gear································································· 2 -31

3.12 Measuring the cylinder bore·································································· 2 -32

3.13 Measuring the cylinder block top face for distortion ··································· 2 -32

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 18

1. Cylinder Head, Valve Mechanism

1.1 Measuring the cylinder head bottom face
distortion

Using a straight edge across the bottom face of
the cylinder head and a thickness gauge, measure
for any distortion. If the measured distortion
exceeds the limit, correct with a surface grinder.

Unit: mm (in.)

Standard value Limit

Cylinder head bottom
face distortion

0.05 less

(0.002 less)

0.10

(0.004)

1.2 Measuring the rocker arm bore and the
rocker shaft diameter

Measure the rocker arm bore and the rocker shaft
diameter to obtain the arm-to-shaft clearance. If
the clearance is between the standard value and
the limit, replace the rocker arm. If the clearance
is equal to or exceeds the limit, replace both the
rocker arm and shaft.

Unit: mm (in.)

Nominal

value

Standard value Limit

Rocker arm
inner
diameter

φ19

(0.749)

18.910 to 18.930

(0.7450 to 0.7458)

―

Rocker shaft
diameter

φ19

(0.749)

18.880 to 18.898

(0.7438 to 0.7445)

―

Arm-to-shaft
clearance

―

0.012 to 0.050

(0.0005 to 0.002)

0.200

(0.0079)

1.3 Measuring the valve spring for
squareness and free length

Measure the valve spring for squareness, free
length, etc. If any of the measured values
exceeds the limit, replace the spring.

Unit: mm (in.)

Standard value Limit

Free length 47 (1.85) 46 (1.81)
Squareness

θ=2.0º or less

△(gap)=0.2 (0.0079)

or less

Lf=47 (1.8504)

△=0.5

(0.0197)

across the

entire

length
Installed
length/load

mm (in.)/N

(kgf) [lbf]

39.0 (1.536)/
131 to 145

(13.3 to 14.7)

[29 to 33]

30.1 (1.185)/
279 to 309

(28.5 to 31.5)

[63 to 69]

-15%

Measuring the rocker arm inner diameter

and the rocker shaft diameter

Measuring the cylinder head bottom face

for distortion

θ

Measuring the spring for squareness

and free length

Measuring locations
and directions

Measuring
direction

Measuring
direction

Measuring
location

Free length

Spring squareness (gap)

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 19

1.4 Measuring the push rod for bend

If the measured value exceeds the limit, replace
the push rod.

Unit: mm (in.)

Limit

Push rod bend 0.3 (0.012)

Note: Use a dial gauge to measure the push rod for

bend.

1.5 Measuring the valve stem diameter

Measure the valve stem diameter. If the
measured value is less than the limit, replace with
a new part. Replace also when the valve stem has
excessively uneven wear.

Unit: mm (in.)

Nominal

value

Standard

value

Limit

Inlet

φ6.6

(0.260)

6.565
to 6.580

(0.2586

to 0.2592)

6.500

(0.256)
Valve stem
diameter

Exhaust

φ6.6

(0.260)

6.530
to 6.550

(0.2572

to 0.2580)

6.500

(0.256)

1.6 Measuring the clearance between the
valve stem and guide

Measure the valve guide inner diameter using an
inside micrometer.
The valve guide wears at the top and bottom ends.
Therefore, both ends need to be measured
orthogonally. If the measured value exceeds the
limit, replace with a new part.

Unit: mm (in.)

Nominal

value

Standard

value

Limit

Inlet

―

0.020
to 0.050

(0.0008

to 0.002)

0.100

(0.004)

Valve stem

-to-guide
clearance

Exhaust

―

0.050
to 0.085

(0.002

to 0.003)

0.150

(0.006)

Installed valve guide
protrusion

10

(0.394)

9.5 to 10.5

(0.3743

to 0.4137)

―

Note: Before measuring the valve stem-to-guide

clearance, remove carbon from the valve and the
valve guide.

Measuring the valve stem diameter

Measuring the push rod bend

1/21/2

Push rod

Measuring the valve guide inner diameter

Measuring
direction

Measuring
location

Inside micrometer

Measuring
direction

Measuring
location

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 20

1.7 Replacing the valve guide

(1) Using a punching tool, remove the valve guide

from the bottom to the top of the cylinder head.

(2) Using a press, insert a new valve guide from the

top of the cylinder head so that the valve guide
protrusion above the cylinder head face is to the
indicated dimension.

(3) With the valve guide press-fit into position, insert

a new valve to verify that it slides smoothly
inside the valve guide.

(4) Check the valve face-to-seat contact.

1.8 Inspecting the valve face

(1) Apply a thin coating of red lead onto the valve

face. Then, using a valve lapper (available on the
market), check the valve face-to-seat contact.

(2) The valve face contact area with the valve seat

should be uniform and in the middle of the face.
If not, reface with valve facer.

(3) If the measured valve head margin (valve head

thickness) is less than the limit, replace the valve.

Unit: mm (in.)

Standard

value

Limit

Valve head margin

1.35 to 0.65

(0.0531 to 0.0650)

0.5

(0.0197)

Valve guide protrusion

above the cylinder head face

Inspecting the valve face

Valve seat-to-face contact

Valve head sinkage

Red lead

Valve lapper

Valve head
sinkage

Valve head
margin

Valve guide

Cylinder head

10

0.5 mm

(0.39

0.20 in.)

[15 mm]

(0.59 in.)

Good

Bad

Contact area
(in the middle of the
valve face)

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 21

(4) If the measured valve head sinkage exceeds the

limit, correct the valve seat or replace the
cylinder head assembly.

Unit: mm (in.)

Standard

value

Limit

Valve head sinkage

0.25 to 0.75

(0.0098±0.0295)

1.5

(0.0600)

1.9 Correcting the valve face

If the valve face is excessively worn, correct with
a valve refacer.

Note: (a) When grinding, set the refacer at 45º relative

to the valve face.

(b) The valve head margin should be maintained

above the limit. If it appears that the
minimum margin cannot be maintained after
refacing, replace the valve.

1.10 Correcting the valve seat

(1) Before correcting the valve seat, check the valve

stem-to-guide clearance and, if necessary,
replace the valve guide.

(2) Grind with a valve seat cutter (available on the

market) or a valve seat grinder until the valve seat
width and angle meet specification.

Note: Valve seat correction should be limited as

minimum as possible.

Unit: mm (in.)

Standard

value

Limit

Valve seat angle 45°

―

Valve seat width

1.30 to 1.80

(0.0512 to 0.0709)

2.5

(0.0985)

(3) After correction, lap the valve face against the

valve seat using lapping compound.

Correcting the valve face

Correcting the valve seat

Valve seat angle and width

Refacer set at 45
relative to the
valve face

Valve contact width

1.3 to 1.8 mm
(0.05 to 0.07 in.)

60

45

30

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 22

1.11 Lapping the valve face against the valve
seat

If the valve seat is corrected or the valve is
replaced, be sure to lap the valve face against the
valve seat in the following manner.

(1) Apply a light coating of lapping compound

evenly over the valve face.

Note: (a) Take care not to allow lapping compound to

attach to the valve stem.

(b) Use medium lapping compound (120 to 150

mesh) first, then finish off with fine lapping
compound (200 mesh or above).

(c) Lapping compound spreads more evenly if it

is mixed with a small amount of engine oil.

(2) Using a valve lapper, lap the valve face against

the valve seat repeatedly while rotating it
gradually.

(3) Wash away the lapping compound in light oil or

other similar liquid.

(4) Apply engine oil onto the lapped faces and lap

them again.

(5) Check the lapped faces for correct contact.

1.12 Replacing the combustion jets

Replace the combustion jets only when they are
cracked or faulty.

(1) To extract the combustion jet, insert a round rod

with a diameter of approx. 6 mm (0.23 in.) into
the glow plug mounting hole and gently tap the
periphery of the combustion jet bore.

(2) To install the jet, tap it into the mounting hole

using a plastic hammer or other similar tool.
Ensure that the nozzle hole faces the center of the
cylinder.

Lapping the valve face against the valve seat

Extracting the combustion jet

Tapping the combustion jet into place

Valve lapper

Lapping
compound

Round rod

Combustion
jet

1

4

3

0

Combustion
jet

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 23

2. Flywheel, Timing Gear, Camshaft

2.1 Measuring the flywheel flatness

Place the flywheel on a surface plate. Run a dial
gauge over the frictional surface of the flywheel
to measure the flatness.
If the measured value exceeds the limit, grind the
frictional surface.

Unit: mm (in.)

Standard

value

Limit

Flywheel flatness

0.150 (0.0059)
or less

0.50 (0.0197)

2.2 Replacing the ring gear

Check the ring gear for fractured or excessively
worn gear teeth. If faulty, replace in the
following manner.

(1) Removing the ring gear

(a) Using an acetylene torch or other similar

equipment, heat the ring gear evenly.

(b) Using a hammer and a ro d, tap the ring gear

evenly on the entire periphery until the gear

comes off.
(2) Installing the ring gear
Using a piston heater or other similar equipment,

heat the ring gear [to approximately 150℃ (302
°Ｆ) or less]. With the gear warmed up, install it
onto the flywheel with the un-chamfered side
first.

2.3 Measuring the timing gear backlash

Measure the backlash between the gears and use
the measurements as references upon reassembly.
If any of the measured values exceeds the limit,
replace all gears unless otherwise specified.

Unit: mm (in.)

Standard value Limit

Crank gear - idler
gear
Idler gear - valve
camshaft gear
Idler gear - pump
camshaft gear

0.040 to 0.120

(0.0015 to 0.0047)

Valve camshaft
gear - PTO gear

0.080 to 0.190

(0.0032 to 0.0075)

Timing gear backlash

Pump camshaft
gear - oil pump
gear

0.070 to 0.200

(0.0028 to 0.0079)

0.300

(0.0120)

Measuring the flywheel flatness

Removing the ring gear

Measuring the timing gear backlash

Flywheel

Ring gear

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 24

2.4 Measuring the clearance between the

idler gear and the idler shaft

Measure the inner diameter of the idler gear.
Measure the idler shaft diameter. If the
difference between the two exceeds the limit,
replace the idler gear or the idler shaft.

Unit: mm (in.)

Standard

value

Limit

Idler gear-to-shaft
clearance

0.020 to 0.070

(0.0008 to 0.0028)

0.200

(0.0079)

2.5 Replacing the idler shaft

When installing the idler shaft into the cylinder
block, observe the dimension indicated.

2.6 Measuring the clearance between the

camshaft journal and the bushing

Measure the camshaft journal diameter. Measure
the inner diameter of the bushing on the cylinder
block. If the difference between them exceeds
the limit, replace the bushing.

Unit: mm (in.)

Standard

value

Limit

Camshaft
journal-to-bushing
clearance

0.050 to 0.125

(0.0020 to 0.0049)

0.150

(0.0059)

Measuring the idler gear-to-shaft clearance

Replacing the idler shaft

Measuring the camshaft journal diameter

Measuring the camshaft bushing inner

diameter

Measuring
direction

Measuring
location

26.5 0.5 mm
(1.04

0.02 in.)

Measuring
direction

Measuring
location

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 25

2.7 Extracting the camshaft bushing

(1) Remove the camshaft bushing using the special

tool Camshaft Bushing Installer in the following
manner.

Special tool Part number

Camshaft Bushing Installer ST332340

(2) Remove the oil pan.
(3) Using the punching side of the installer, punch

the bushing off and into the cylinder block. Take
it out of the block by slightly deforming it.

2.8 Press-fitting the camshaft bushing

Press-fit the bushing while ensuring that the oil
holes of the bushing align with the oil galleries in
the cylinder block.

2.9 Measuring the camshaft cam height

Measure the camshaft cam height as illustrated.
If the measured value is less than the limit,
replace the camshaft.

Unit: mm (in.)

Standard

value

Limit

Camshaft cam height
(including lobe)

35.720±0.1

(1.4073±0.0039)

34.720

(1.3679)

2.10 Measuring the fuel injection pump shaft

cam height

Measure the cam height as illustrated. If the
measured value is less than the limit, replace the
fuel injection pump shaft.

Unit: mm (in.)

Standard

value

Limit

Fuel injection pump
shaft cam height
(including lobe)

44±0.1

(1.736±0.0039)

43

(1.6942)

Extracting the camshaft bushing

Press-fitting the camshaft bushing

Measuring the camshaft cam height

Measuring the fuel injection pump shaft cam

height

Measuring
location

Measuring
direction

Measuring
location

Measuring
direction

Cylinder block
front face

Camshaft
bushing

Camshaft bushing
installer

1 mm (0.04 in.)

1 mm
(0.04 in.)

Oil hole

Notch on the
bushing

Mating mark

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 26

2.11 Inspecting the cam-to-tappet contact

Inspect the tappet contact face with the cam. If
abnormally worn, replace the tappet.

2.12 Measuring the clearance between the

tappet and the tappet guide

Measure the tappet diameter. Measure the tappet
guide bore in the cylinder block. If the difference
between them exceeds the limit, replace the
tappet.

Unit: mm (in.)

Limit

Tappet-to-guide clearance 0.150 (0.0059)

Cam-to-tappet contact

Measuring the clearance between the tappet

and the tappet guide

Good

Bad

Bad

Measuring
direction

Measuring
direction

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 27

3. Cylinder Block, Crankshaft, Pistons, Oil Pan

3.1 Measuring the piston diameter

Using a micrometer, measure the piston diameter
across the piston skirt and squarely with the
piston pin, as illustrated.
If the measured value is less than the limit,
replace with a new part. The maximum
allowable variation in weight among the pistons
on the same engine is 5 grams (0.18 oz).

Unit: mm (in.)

Nominal

value

Standa rd

value

Limit

STD

78.00
(3.07)

77.93 to 77.95

(3.070 to 3.071)

77.80

(3.065)

0.25
OS

78.25
(3.08)

78.18 to 78.20

(3.080 to 3.081)

78.05

(3.075)

Piston
diameter

0.50
OS

78.50
(3.09)

78.43 to 78.45

(3.090 to 3.090)

78.30

(3.085)
Max. allowable variation in
weight among pistons on the
same engine:

5 g (0.18 oz)

or less

―

3.2 Measuring the clearance between the
piston ring and the ring groove

(1) Measure the piston ring-to-groove clearance. If

the measured value exceeds the limit, replace the
piston ring.

Unit: mm (in.)

Standard value Limit

No. 1 ring 0.09 to 0.11 (0.0035 to 0.0043) 0.300 (0.012)
No. 2 ring 0.07 to 0.11 (0.0028 to 0.0043) 0.200 (0.008)
Oil ring 0.03 to 0.07 (0.0012 to 0.0028) 0.200 (0.008)

(2) With the new piston ring installed, measure the

ring-to-groove clearance again. If the measured
value still exceeds the limit, replace the piston.

3.3 Measuring the piston ring gap

Install the piston ring being measured into the
gauge or a new cylinder. T hen, using a thickness
gauge, measure the piston ring gap. If the
measured value exceeds the limit, replace all
rings of the relevant piston as a set.

STD=78

+0.03

0

mm (3.07

+0.0012

0

in.)

Gauge bore size

25 OS=78.25

+0.03

0

mm (3.08

+0.0012

0

in.)

50 OS=78.50

+0.03

0

mm (3.09

+0.0012

0

in.)

Note: To install a piston ring into the gauge, use a

piston to push the ring evenly.

Unit: mm (in.)

Standard value Limit

No. 1 ring 0.15 to 0.30 (0.006 to 0.012)
No. 2 ring 0.15 to 0.35 (0.006 to 0.014)

Piston
ring
gap

Oil ring 0.20 to 0.40 (0.008 to 0.016)

1.50

(0.06)

Measuring the piston diameter

Measuring the piston ring-to-groove clearance

Measuring the piston ring gap

Measuring location

Measure squarely
with piston pin

Thickness gauge

No. 1 piston
ring-to-groove
clearance

No. 2 piston
ring-to-groove
clearance

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 28

3.4 Measuring the clearance between the
piston pin and the pin boss

Measure the piston pin diameter. Measure the
bore size of the piston pin boss. If the difference
between them exceeds the limit, replace with
new parts.

Unit: mm (in.)

Nominal

value

Standard

value

Limit

Piston pin
diameter

φ23

(0.9062)

22.944 to 23.000

(0.9039 to 0.9062)

―

Piston
pin-to-boss
clearance

―

0.006 to 0.018

(0.0002 to 0.0007)

0.050

(0.002)

3.5 Measuring the connecting rod bend and
twist

(1) Measure C and l as illustrated. If measured C is

more than 0.05 mm (0.0020 in.) per 100 mm
(3.937 in.) of measured l, correct the connecting
rod using a press.

Unit: mm (in.)

Standard value Limit

Connecting rod
bend and twist

0.05/100

(0.002/3.940)

or less

0.15/100

(0.006/3.940)

(2) Normally, a connecting rod aligner is used to

measure the connecting rod for bend and twist.

Note: Before measuring the connecting rod for bend,

tighten the connecting rod cap nuts to the
specified torque.

(3) When measuring connecting rod bend with the

piston installed to the connecting rod, place the
piston/rod assembly on a surface plate such that
the top of piston lies on the plate. Then, insert a
round rod with the same diameter as the crank pin
into the connecting rod large end. Using a dial
gauge, measure the top of the round rod for any
variation in height.

Measuring the piston pin-to-boss clearance

Measuring the connecting rod bend and twist

Using a connecting rod aligner to measure

the rod bend and twist

Using a dial gauge to measure

the connecting rod for bend

Measuring
location

Measuring
direction

A

B

C

D

Piston pin

C

C

C

100

0.05

C

100

0.05

Connecting rod twist

Connecting rod bend

l

l

l

l

Tightening torque
for connecting
rod cap nut

32.4 to 37.3 N

m

(3.3 to 3.8 kgf

m)

[23.9 to 27.5 lbf

ft]

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 29

3.6 Measuring the connecting rod end play

Install the connecting rod and the rod cap onto
the mating crank pin. Tighten the cap nuts to the
specified torque. Using a thickness gauge,
measure the gap (end play).
If the measured value exceeds the limit, replace
the connecting rod and the rod cap.

Unit: mm (in.)

Standard value Limit

Connecting rod end
play

0.10 to 0.35

(0.004 to 0.014)

0.50

(0.012)

3.7 Inspecting the oil clearance for
connecting rod bearings

(1) Install the connecting rod bearings (upper and

lower) into the connecting rod large end. Tighten
the cap nuts to the specified torque. Measure the
inner diameter of the bearings.

(2) Measure the diameter of the mating crank pin.

The difference between the bearing inner
diameter and the crank pin diameter is the oil
clearance for the bearings.

Unit: mm (in.)

Nominal

value

Standard

value

Limit

Crank pin
diameter

φ48

(1.8912)

47.950 to 47.964

(1.8892 to 1.8897)

―

Oil clearance
for connecting
rod bearings

―

0.025 to 0.072

(0.0010 to 0.0028)

0.150

(0.0059)

(3) If the measured oil clearance exceeds the limit,

replace the bearings. With the new bearings
installed, measure the oil clearance again.

(4) If the measured oil clearance still exceeds the

limit, use the undersize bearings [0.25 mm
(0.0098 in.), 0.50 mm (0.0197 in.), 0.75 mm
(0.0295 in.) U.S.]

Also, grind the crank pin accordingly to the

finished dimension shown below.

Crank pin ground dimensions

Unit: mm (in.)

Finished dimension

0.25 (0.0098)

φ47.75

-0.035

-0.050

(1.881

-0.0014

-0.0020

)

0.50 (0.0197)

φ47.50

-0.035

-0.050

(1.871

-0.0014

-0.0020

)

Crank pin
undersize

0.75 (0.0295)

φ47.25

-0.035

-0.050

(1.861

-0.0014

-0.0020

)

Measuring the connecting rod end play

Measuring the connecting rod bearings

inner diameter

Measuring the crank pin diameter

Measuring
direction

Measuring
location

Thickness gauge

Tightening torque

32.4 to 37.3 N

m

(3.3 to 3.8 kgf

m)

[23.9 to 27.5 lbf

ft]

Measuring
direction

Measuring
location

Tightening torque

32.4 to 37.3 N

m

(3.3 to 3.8 kgf

m)

[23.9 to 27.5 lbf

ft]

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 30

(a) If any of the crank pins need grinding, grind

all crank pins on the same crankshaft to the
same dimension.

(b) Finish the fillets to a radius of 2 mm (0.08

in.).

3.8 Inspecting the main bearings oil
clearance

(1) Place the main bearings (upper and lower) onto

the cylinder block and the main bearing cap.
Assemble them together and tighten the cap bolts
to the specified torque. Measure the inner
diameter of the main bearings.

(2) Measure the diameter of the mating crank journal.

The difference between the main bearings inner
diameter and the crank journal diameter is the oil
clearance for the main bearings.

Unit: mm (in.)

Nominal

value

Standard

value

Limit

Crank journal
diameter(STD)

φ52

(2.0488)

51.985
to 52.000

(2.0482

to 2.0488)

―

Oil clearance for
main bearings

―

0.030

to 0.077

(0.0012

to 0.003)

0.100

(0.0040)

(3) If the measured oil clearance exceeds the limit,

replace the main bearings. With the new bearings
installed, measure the oil clearance again.

(4) If the measured oil clearance still exceeds the

limit, use the undersize bearings [0.25 mm
(0.0098 in.), 0.50 mm (0.0197 in.), 0.75 mm
(0.0295 in.) U.S.]

Also, grind the crank journal accordingly to the

finished dimension shown below.

Crank journal ground dimensions

Unit: mm (in.)

Finished dimension

0.25 (0.0098)

φ51.75

0

-0.015

(2.0374

0

-0.006

)

0.50 (0.0197)

φ51.50

0

-0.015

(2.0276

0

-0.006

)

Crank
journal
undersize

0.75 (0.0295)

φ51.25

0

-0.015

(2.0177

0

-0.006

)

Finished radius dimension of fillet

Measuring the main bearings inner diameter

Measuring the crank journal diameter

Measuring
location

Measuring
direction

R2.5 mm
(0.098 in.)

Measuring
location

Measuring
direction

Tightening torque

49.0 to 53.9 N

m

(5.0 to 5.5 kgf

m)

[36.2 to 39.8 lbf

ft]

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 31

(a) If any of the crank journals need grinding,

grind all crank journals on the same
crankshaft to the same dimension.

(b) Finish the fillets to a radius of 2.5 mm (0.098

in.).

3.9 Measuring the crankshaft for bend

Support the crankshaft at the front and rear crank
journals with a V block. Using a dial gauge,
measure the center journal for a swing of the
gauge needle (to both directions). If the
measured value moderately exceeds the standard
value, correct the bend by grinding. If the
measured value far exceeds the standard value,
correct the bend using a press or other similar
equipment.
If the measured value exceeds the limit, replace
the crankshaft.

Unit: mm (in.)

Standard value Limit

Crankshaft bend 0.025 (0.0010) 0.050 (0.0020)

3.10 Removing the crankshaft gear

Use a gear puller to remove the crankshaft gear.

Note: Do not remove the crankshaft gear unless the

crankshaft or the gear is faulty.

3.11 Installing the crankshaft gear

(1) Install the key to the crankshaft.
(2) Align the keyway in the crankshaft gear with the

key on the crankshaft, and press-fit the gear fully
until it stops.

Finished radius dimension of fillet

Measuring the crankshaft bend

Removing the crankshaft gear

Installing the crankshaft gear

Gear puller

R2 mm
(0.08 in.)

R2 mm
(0.08 in.)

Align these

ENGINE MAIN PARTS - INSPECTION AND CORRECTION

2 - 32

3.12 Measuring the cylinder bore

Using a cylinder gauge, measure the cylinder
bore and cylindricality. If any of the cylinders
exceeds the limit, bore all cylinders of the same
engine and replace the pistons and the piston
rings with oversize parts.
Measure at 3 locations as shown in the fig., each
in directions A and B.

Unit: mm (in.)

Pistons and piston

rings available

Cylinder bore

Size Code

Standard

value

Limit

STD STD

φ78

+0.03

0

(3.07

+0.012

0

)

0.25 OS 25

φ78.25

+0.03

0

(3.08

+0.012

0

)

0.50 OS 50

φ78.50

+0.03

0

(3.09

+0.012

0

)

Standard

value

+0.2

(0.0080)

Cylinder bore out of

cylindricality

±0.01

(0.0004)

max

―

3.13 Measuring the cylinder block top face for
distortion

Using a straight edge across the top face of the
cylinder block and a thickness gauge, measure
for any distortion.
If the measured distortion exceeds the limit,
correct by grinding the top face.

Unit: mm (in.)

Standard

value

Limit

Cylinder block top face
distortion

0.05 (0.002)
max

0.10 (0.004)

The combined grinding limit for the cylinder
block top face and the mating cylinder head
bottom face is 0.2 mm (0.008 in.).

Measuring the cylinder bore

Measuring the cylinder block top face for

distortion

A

B

Measuring
location

Measuring
direction

Measuring location,
Measuring direction



1. Cylinder Block, Crankshaft, Pistons, Oil Pan······································ 2 -34

1.1 Installing the main bearings ·································································· 2 -34

1.2 Installing the crankshaft········································································ 2 -34

1.3 Installing the main bearing caps····························································· 2 -34

1.4 Inserting the side seals ········································································ 2 -35

1.5 Assembling the piston onto the connecting rod········································· 2 -36

1.6 Installing the piston rings······································································ 2 -37

1.7 Installing the piston/connecting rod assemblies ········································2 -37

1.8 Installing the connecting rod caps·························································· 2 -38

1.9 Installing the oil strainer ······································································· 2 -38

1.10 Installing the oil pan············································································· 2 -38

2. Flywheel, Timing Gear, Camshaft······················································· 2 -40

2.1 Installing the front plate········································································ 2 -40

2.2 Installing the oil pump·········································································· 2 -40

2.3 Rotating the engine············································································· 2 -40

2.4 Tapping the fuel injection pump camshaft into place·································· 2 -40

2.5 Installing the camshaft ·········································································2 -41

2.6 Installing the idler gear········································································· 2 -41

2.7 Installing the timing gear case······························································· 2 -41

2.8 Tightening the crankshaft pulley nut ······················································· 2 -42

2.9 Installing the PTO gear ········································································ 2 -42

2.10 Inserting the tappets············································································ 2 -42

2.11 Installing the oil seal case····································································· 2 -42

2.12 Installing the rear plate········································································· 2 -43

2.13 Installing the flywheel housing······························································· 2 -43

2.14 Installing the flywheel··········································································· 2 -43

3. Cylinder Head, Valve Mechanism······················································· 2 -44

3.1 Cleaning the bottom face of the cylinder head·········································· 2 -44

3.2 Installing the valve stem seals······························································· 2 -44

3.3 Installing the valve springs···································································· 2 -44

3.4 Installing the valve locks······································································· 2 -44

3.5 Installing the cylinder head gasket ························································· 2 -45

3.6 Installing the cylinder head ··································································· 2 -45

3.7 Tightening the cylinder head bolts·························································· 2 -45

3.8 Inserting the push rods ········································································ 2 -45

3.9 Assembling the rocker shaft assembly···················································· 2 -46

3.10 Installing the rocker shaft assembly························································ 2 -46

3.11 Adjusting the valve clearance································································ 2 -46

3.12 Installing the rocker cover····································································· 2 -46

ENGINE MAIN PARTS - REASSEMBLY

ENGINE MAIN PARTS - REASSEMBLY

2 - 34

1. Cylinder Block, Crankshaft, Pistons, Oil Pan

To reassembly, follow the disassembly sequence in
reverse.

1.1 Installing the main bearings

(1) Install the main bearings (upper and lower) onto

the cylinder block and the main bearing cap,
ensuring that the lugs engage with the lug
grooves.

(2) The flanged main bearings should be installed

onto the No. 3 crank journal.

(3) Lightly coat the inner surface of each bearing

with engine oil.

1.2 Installing the crankshaft

(1) Wash the crankshaft thoroughly in wash oil.

Dry the crankshaft using compressed air.

(2) While holding the crankshaft horizontally, lower

it slowly onto the cylinder block.

(3) Lightly coat the crank journals with engine oil.

1.3 Installing the main bearing caps

(1) Apply sealant onto the mating faces of the front

and rear main bearing caps and the cylinder
block.

Sealant ThreeBond 1212

(2) Install the main bearing caps so that their arrow

marks point the front of the engine and that the
cap numbers are in the order from the front to
the rear of the engine.

(3) Loosely tighten the cap retaining bolts.

Install the front and rear main bearing caps so
that they are flush with the cylinder block.

Installing the main bearings

Installing the crankshaft

Correct installation of main bearing caps

Installing the main bearing cap

ENGINE MAIN PARTS - REASSEMBLY

2 - 35

(4) Tighten the main bearing cap bolts progressively

in diagonal sequence and tighten to the specified
torque at the final step.

(5) Ensure that the crankshaft rotates smoothly,

without any binding.

(6) Measure the crankshaft end play (refer to Page

2-14).
If the measured value exceeds the limit, loosen
and retighten the main bearing cap bolts.

1.4 Inserting the side seals

(1) Apply sealant to the periphery of new side seals.

Sealant ThreeBond 1212

(2) With the seal radius faced outside, insert the side

seals with your hand into the front and rear of
the cylinder block.

(3) Using a flat piece, push the last portion of the

side seals fully into the cylinder block, taking
care not to bend the seals.

Tightening the main bearing cap bolts

Ensure that the crankshaft rotates smoothly

Face the side seals correctly

Inserting the side seal

Side seal

Radius Radius

Tightening torque:

49.0 to 53.9 N

m

(5.0 to 5.5 kgf

m)

[36.2 to 39.8 lbf

ft]

ENGINE MAIN PARTS - REASSEMBLY

2 - 36

1.5 Assembling the piston onto the
connecting rod

(1) Install the special tool Piston Pin Setting Tool

onto a hydraulic press.

Special tool Part number

Piston Pin Setting Tool 31A91-00100

(2) Place the connecting rod on the tool. Coat the

connecting rod small end with engine oil.

(3) Install the piston onto the connecting rod so that

the arrow on the top face of the piston faces the
side of the connecting rod that has the engine
type embossed. Insert the piston pin slightly
into the pin boss.

(4) Using the push rod of the tool, press the piston

pin into the pin boss.

When the hydraulic press needle almost
exceeds the 50 kgf (110.23 lbf) while the
piston pin is being pressed, stop pressing the
pin. Reset the push rod and start pressing
again.

(5) With the piston and the connecting rod

assembled together, check that they slide
smoothly about the piston pin.

Piston Pin Setting Tool

Inserting the piston pin

Inserting the piston pin with a hydraulic press

Check that the piston and the connecting rod

slide smoothly about the piston pin

ENGINE MAIN PARTS - REASSEMBLY

2 - 37

1.6 Installing the piston rings

Using the special tool Piston Ring Pliers, install
the No. 1 ring, No. 2 ring, and oil ring onto the
piston.

Special tool Part number

Piston Ring Pliers 31391-12900

Note: (a) Install the rings so that “T” mark faces the

top of the piston.

(b) The oil ring should be installed so that the

butt joint of the coil spring is located at 180o
relative to the ring gap as illustrated.

1.7 Installing the piston/connecting rod
assemblies

(1) Apply engine oil onto the periphery of the piston

and the piston rings.

(2) Position the piston ring gaps as illustrated. The

gaps should not face the same direction as the
piston pin or squarely with the piston pin

(3) Install the connecting rod bearing (upper) onto

the connecting rod, ensuring that the lug
engages with the lug groove.

(4) Rotate the crankshaft until the crank pin onto

which the piston/connecting rod assembly is
being installed comes to the top dead center.

(5) Face the piston/connecting rod assembly so that

the arrow mark on top of the piston points to the
timing gear case side (front) of the engine.

(6) Using a piston guide (available on the market),

insert the piston/connecting rod assembly from
the top of the cylinder block down.

Do not tap the piston too hard. Doing so may
break the piston rings or damage the crank
pin.

Piston ring arrangement

Assembling the oil ring

Locating the piston ring gaps

Installing the piston/connecting rod assembly

Top face mark

No. 1 compression
ring

No. 2 compression
ring

Oil ring

Oil ring gap

Coil spring butt
joint

180

No. 2 ring coil
spring butt joint

No. 1 ring gap

Oil ring gap

Front of
engine

Piston guide

ENGINE MAIN PARTS - REASSEMBLY

2 - 38

1.8 Installing the connecting rod caps

(1) While pressing the top of piston down to keep

the connecting rod large end attached to the
crank pin, rotate the crankshaft 180°.

(2) Install the connecting rod bearing (lower) onto

the connecting rod cap, ensuring that the lug
engages with the lug groove.

(3) Install the bearing cap onto the connecting rod,

observing the mating marks made during
disassembly.

Note: If a new connecting rod without mating marks is

being installed, ensure that the lug grooves,
designed to prevent the bearings from turning,
are assembled on the same side.

(4) Tighten the connecting rod cap nuts alternately

in several steps, and finally to the specified
torque.

(5) Check the connecting rod end play.

1.9 Installing the oil strainer

(1) Position the cylinder block with the oil pan

mounting face up.

(2) Install the oil strainer so that the tip of the

strainer will not contact the oil pan when
installed. Tighten the nut to the specified
torque.

1.10 Installing the oil pan

(1) Clean the mating faces of the cylinder block and

the oil pan.
Apply sealant to the entire periphery of the oil
pan mounting face of the cylinder block.

Sealant ThreeBond 1207C

Installing the connecting rod cap

Tightening the connecting rod cap nuts

Installing the oil strainer

Applying sealant to the oil pan mounting face

of the cylinder block

Lug groove

Cylinder No.

Tightening torque:

32.4 to 37.3 N

m

(3.3 to 3.8 kgf

m)

[23.9 to 27.5 lbf

ft]

Tightening torque:

24.5 to 29.4 N

m

(2.5 to 3.0 kgf

m)

[18.1 to 21.7 lbf

ft]

ENGINE MAIN PARTS - REASSEMBLY

2 - 39

Note: (a) Apply sealant in a bead of 4 mm (0.1575 in.)

and in the illustrated pattern.

(b) Cutting the end of the sealant tube at the

illustrated location will provide a 4 mm
(0.1575 in.) bead.

(2) Tighten the oil pan retaining bolts diagonally in

several steps, and finally to the specified torque.

Sealant application pattern

Cutting the end of sealant tube

Installing the oil pan

Cut here

Tightening torque:

9.80 to 12.7 N

m

(1.0 to 1.3 kgf

m)

[7.2 to 9.4 lbf

ft]

R17 (4 front and rear
locations in total)

Apply sealant as lined

9.5 mm
(0.37 in.)

R7 from hole center
(same for all 17 holes)

36 mm
(1.42 in.)

Rear

Front

R40 corresponding to
hole centers
(same for all 4 corners)

5 mm
(0.20 in.)

Apply oil pan liquid gasket here (top face)

ENGINE MAIN PARTS - REASSEMBLY

2 - 40

2. Flywheel, Timing Gear, Camshaft

To reassembly, follows the disassembly sequence in
reverse.

2.1 Installing the front plate

(1) Completely scrape off any remaining gasket

from the cylinder block and the front plate.

(2) Install the front plate onto the cylinder block.

Tighten the four retaining bolts.

(3) Apply sealant onto the side of the gasket that is

to be mated to the front plate. Attach the
gasket onto the front plate. The sealant will
prevent the gasket from moving.

2.2 Installing the oil pump

(1) Ensure that the oil pump is correctly fitted with

packing.

(2) Install the oil pump onto the crankcase.

Tighten the three retaining bolts evenly.

(3) Ensure that the oil pump gear rotates smoothly.

2.3 Rotating the engine

(1) Install two studs (M12×1.25) into the flywheel

mounting holes in the crankshaft.

(2) Place a bar between the studs and rotate the

crankshaft until the No. 1 cylinder comes to the
top dead center.

2.4 Tapping the fuel injection pump
camshaft into place

(1) Insert the fuel injection pump camshaft

(complete with the bearing and the gear) into the
cylinder block.

(2) Tap the gear with a plastic hammer until the

bearing is completely inserted into the mounting
hole in the cylinder block.

(3) Ensure that the fuel injection pump camshaft

rotates smoothly.

(4) Tighten the stopper bolt.

Front plate retaining bolts

Installing the oil pump

Rotating the engine

Tapping the fuel injection pump camshaft

into place

ENGINE MAIN PARTS - REASSEMBLY

2 - 41

2.5 Installing the camshaft

(1) Apply engine oil to the journals and cams.
(2) Insert the camshaft (complete with the ca mshaft

gear) into the cylinder block.

Take care not to damage the journals or cams
when inserting the camshaft into the cylinder
block.

(3) Using an appropriate torque wrench and socket,

tighten the thrust plate mounting bolts to the
specified torque.

(4) Ensure that the camshaft rotates smoothly.

Also ensure that there is some end play by
sliding the camshaft to the front and rear.

2.6 Installing the idler gear

(1) Apply engine oil to the idler shaft.
(2) Install the idler gear so that the timing marks are

aligned with those of the meshing gears.

(3) Check the backlash between the gears.
Note: Refer to “Measuring the timing gear backlash”

on Page 2-23.

2.7 Installing the timing gear case

(1) Apply sealant onto the gasket and stick it in

place. Then, install the timing gear case onto
the front plate.

(2) Apply engine oil to the oil seal lips.
(3) Tighten the timing gear case retaining bolts.

Installing the camshaft

Installing the thrust plate

Aligning the timing marks

Installing the timing gear case

Apply engine oil

Tightening torque:

9.8 to 11.8 N

m

(1.0 to 1.2 kgf

m)

[7.2 to 8.7 lbf

ft]

ENGINE MAIN PARTS - REASSEMBLY

2 - 42

2.8 Tightening the crankshaft pulley nut

(1) Use the studs and the bar described in Section

“2.3” to lock the crankshaft.

(2) While locking the crankshaft, tighten the

crankshaft pulley nut to the specified torque.

The locking studs and bar should be
sufficiently strong to avoid any accident.

2.9 Installing the PTO gear

Drive the PTO gear into the timing gear case.
Ensure that the side of the gear with no oil hole
faces the rear of the engine.

2.10 Inserting the tappets

Apply engine oil to the periphery of the tappets,
and insert them into the tappet holes in the
cylinder block.

2.11 Installing the oil seal case

(1) Install a new oil seal case gasket.
(2) Apply engine oil to the entire periphery of the

oil seal lips, and install the oil seal and case onto
the cylinder block.

Tightening the crankshaft pulley nut

Driving the PTO gear into place

Inserting the tappet

Installing the oil seal case

Apply engine oil

Tightening torque:
147 to 196 N

m

(15.0 to 20.0 kgf

m)

[108.5 to 144.7 lbf

ft]

ENGINE MAIN PARTS - REASSEMBLY

2 - 43

2.12 Installing the rear plate

(1) Install a new rear plate gasket.
(2) Install the rear plate, aligning it with the dowel

pins. Tighten the retaining bolts to the
specified torque.

Note: Install the rear plate complete with the starter.

This will facilitate the subsequent reassembly.

2.13 Installing the flywheel housing

Install the flywheel housing, aligning it with the
knock pins. Tighten the retaining bolts evenly.

Note: Replace the knock pins with new parts if the

knock pins are worn or if a new flywheel
housing is being installed.

2.14 Installing the flywheel

(1) Screw in a safety stud (M12×1.25) into one of

the flywheel retaining bolt holes at the rear end
of the crankshaft.

(2) Insert the flywheel through the safety stud and

onto the crankshaft.

(3) Loosely tighten the three flywheel retaining

bolts.

(4) Replace the safety stud with the 4th retaining

bolt, and loosely tighten it.

(5) Using a torque wrench or other similar tool, lock

the crankshaft pulley nut.

(6) Tighten the flywheel retaining bolts to the

specified torque.

The person who locks the crankshaft pulley
nut should do so with extreme care.
Communicate with each other closely to
prevent accidents.

Installing the rear plate

Installing the flywheel housing

Installing the flywheel

Tightening the flywheel bolts

Tightening torque:

53.9 to 73.5 N

m

(5.5 to 7.5 kgf

m)

[39.8 to 54.2 lbf

ft]

Tightening torque:
127 to 137 N

m

(13.0 to 14.0 kgf

m)

[94.0 to 101.3 lbf

ft]

Safety stud

ENGINE MAIN PARTS - REASSEMBLY

2 - 44

3. Cylinder Head, Valve Mechanism

To reassembly, follows the disassembly sequence in
reverse.

3.1 Cleaning the bottom face of the cylinder
head

Scrape off any gasket from the mating faces of
the cylinder head and the cylinder block, taking
care not to damage the faces.

Note: Use a scraper to roughly remove the remaining

gasket. Then, using an oil stone and engine oil,
polish away fine residue.

3.2 Installing the valve stem seals

Using a box wrench No. 12, install the valve
stem seal on the valve guide.
Ensure that the seal has been correctly installed
the valve guide.

Note: Incorrectly installed stem seals will lead to oil

leaking down through the seal-to-guide gap and
into the combustion chamber.

3.3 Installing the valve springs

Install the valve spring with the white
enamel-coated end facing up.

3.4 Installing the valve locks

Install the valve lock by compressing the valve
spring using a valve lifter.

Do not compress the valve spring too hard as
the bottom of the retainer may contact and
damage the stem seal.

Removing the old gasket

Inserting the valve stem seal

Installing the valve springs

Installing the valve lock

Box wrench No. 12

White enamel
coating

ENGINE MAIN PARTS - REASSEMBLY

2 - 45

3.5 Installing the cylinder head gasket

(1) Ensure that the cylinder block top face and the

piston top faces are clean.

(2) Insert two guide studs (M10×1.25) into the bolt

holes in the cylinder block.

(3) Install the cylinder head gasket through the studs

and onto the cylinder block.

Do not use liquid packing or other similar
sealant.

3.6 Installing the cylinder head

Install the cylinder head through the guide studs
and onto the cylinder block.

3.7 Tightening the cylinder head bolts

(1) Remove the guide studs. Install the cylinder

head bolts.

(2) Tighten the cylinder head bolts in the order

illustrated in a couple of steps, and finally
tighten to the specified torque.

3.8 Inserting the push rods

(1) Insert the push rods into the holes in the cylinder

head.

(2) Ensure that the ball end of the push rod rests on

the recess of the tappet.

Installing the cylinder head gasket

Installing the cylinder head

Tightening order for the cylinder head bolts

Inserting the push rod

Guide stud

Guide stud

13

11

12

14

1

7

9

6

4

3

5

10

8

2

11

1

7

9

6

4

3

5

10

8

2

S4L,S4L2

S3L,S3L2

Front of engine

Tightening torque:

83.4 to 93.2 N

m

(8.5 to 9.5 kgf

m)

[61.5 to 68.7 lbf

ft]

ENGINE MAIN PARTS - REASSEMBLY

2 - 46

3.9 Assembling the rocker shaft assembly

(1) Assemble the rocker shaft components to ensure

the correct reassembly and tighten the retaining
bolt.

(2) Ensue that the rocker arms move smoothly.

3.10 Installing the rocker shaft assembly

(1) Install the valve caps.
(2) Install the rocker shaft assembly onto the

cylinder head. Tighten the mounting bolts to
the specified torque.

3.11 Adjusting the valve clearance

Refer to “1.3 Adjusting the valve clearance”
on Page 8-3.

3.12 Installing the rocker cover

(1) Ensure that the rocker cover is correctly fitted

with gasket.

(2) Tighten the rocker cover retaining bolts to the

specified torque.

Assembling the rocker shaft assembly

Installing the rocker shaft assembly

Adjusting the valve clearance

Installing the rocker cover

Retaining bolt

Tightening torque:

9.81 to 19.6 N

m

(1.0 to 2.0 kgf

m)

[7.2 to 14.5 lbf

ft]

Tightening torque:

9.81 to 12.7 N

m

(1.0 to 1.3 kgf

m)

[7.2 to 9.4 lbf

ft]

1. Fuel Injection Pipes, Fuel Leak-off Pipe, Fuel Injection Nozzles········· 3 - 2

1.1 Removing the fuel injection pipes···························································· 3 - 3

1.2 Removing the fuel injection nozzles························································· 3 - 3

2. Governor ····························································································· 3 - 4

2.1 Removing the governor assembly··························································· 3 - 5

2.2 Removing the governor weights······························································ 3 - 5

3. Fuel Injection Pumps··········································································· 3 - 6

Removing the fuel injection pumps ································································ 3 - 7

FUEL SYSTEM - REMOVAL

FUEL SYSTEM - REMOVAL

3 - 2

1. Fuel Injection Pipes, Fuel Leak-off Pipe, Fuel Injection Nozzles

Replace: Gasket

Removal of fuel injection pipes, fuel leak-off pipe, and fuel injection nozzles

<Removal sequence>

① No. 1 fuel injection pipe
② No. 2 fuel injection pipe
③ No. 3 fuel injection pipe

④ No. 4 fuel injection pipe
⑤ Fuel leak-off pipe
⑥ Fuel injection nozzle

To prevent dirt from entering into the fuel
system, plug the injection pump openings, the
nozzle inlet connectors, and the injection pipes.

FUEL SYSTEM - REMOVAL

3 - 3

1.1 Removing the fuel injection pipes

Remove the fuel injection pipes and the fuel
leak-off pipe.

Note: To prevent dirt from entering into the system,

plug the fuel injection pump openings and the
fuel injection nozzle connectors.

1.2 Removing the fuel injection nozzles

Using a wrench, loosen the fuel injection nozzles.
Remove the nozzles and gaskets.

Note: Use a wire or a screwdriver to remove the fuel

injection nozzle gaskets from the cylinder head.
Faulty gaskets should be replaced.

Removing the fuel injection pipe

Removing the fuel injection nozzle

FUEL SYSTEM - REMOVAL

3 - 4

2. Governor

Replace: Gasket

Removal of the governor

<Removal sequence>

① Bolt

② Governor assembly

③ Gasket

FUEL SYSTEM - REMOVAL

3 - 5

2.1 Removing the governor assembly

(1) Remove the tie-rod cover.
(2) Using a pair of cutting pliers, remove the tie-rod

spring. Disconnect the tie-rod from the pumps.

(3) Remove the governor assembly.

2.2 Removing the governor weights

(1) Remove the sliding sleeve.
(2) Remove the sliding sleeve shaft and then the

governor weights.

Removing the governor assembly

Removing the governor weights

FUEL SYSTEM - REMOVAL

3 - 6

3. Fuel Injection Pumps

Removal of the fuel injection pumps

<Removal sequence>

① Bolt

② Fuel injection pump

③ Shim

FUEL SYSTEM - REMOVAL

3 - 7

Removing the fuel injection pumps

(1) Remove the tie-rod cover.
(2) Using a pair of cutting pliers, remove the tie-rod

spring. Disconnect the tie-rod from the pumps.

(3) Removing the fuel injection pumps
Note: Note the thickness of shim pack for the

adjustment of the fuel injection timing.

Removing the tie-rod

Removing the fuel injection pump

Adjusting
shim

FUEL SYSTEM - REMOVAL

3 - 8

1. Fuel Injection Nozzles ········································································ 3 -10

1.1 Disassembling the fuel injection nozzles ················································· 3 -10

1.2 Inspecting the fuel injection nozzle························································· 3 -10

1.3 Reassembling the fuel injection nozzle ··················································· 3 -12

2. Fuel Injection Pumps·········································································· 3 -13

2.1 Inspecting the fuel injection pumps on vehicle·········································· 3 -13

2.2 Disassembling the fuel injection pumps··················································· 3 -13

2.3 Inspecting the fuel injection pumps························································· 3 -16

2.4 Reassembling the fuel injection pumps··················································· 3 -17

3. Governor ···························································································· 3 -20

3.1 Disassembling and inspecting the governor············································· 3 -20

3.2 Reassembling the governor ·································································· 3 -21

3.3 Installing the torque spring set······························································· 3 -21

4. Fuel Pump·························································································· 3 -22

Inspecting the fuel pump············································································· 3 -22

5. Fuel Filter ··························································································· 3 -23

5.1 Disassembling, inspecting and reassembling the fuel filter
(with a selector cock)

··········································································· 3 -23

5.2 Inspecting the fuel filter (cartridge type)··················································· 3 -23

FUEL SYSTEM - DISASSEMBLY,

INSPECTION AND REASSEMBL Y