Preface

Model Gw4D28 diesel engine is developed based on natural air suction diesel engine model 4JB1 whose
technology was introduced from Isuzu, Japan. This engine features low noise, economical efficiency, fast lowtemperature startup, excellent performance in both low and fast speed, low weight, compact dimension, high reliability
and more powerful.
Model GW4D28 diesel engine is suitable for light truck, Pickup, SUV business car, light passenger car and
other machine powered by diesel engine.
To meet the requirement of the maintenance personnel, technical personnel and management personnel, GW4D28
Diesel Engine Service Manual is complied with technical documents up to minute after arrangement and induction.
The content of this manual is full and detailed. Requirements in the manual are clear and operation is brief.The
manual provides guidance for actual maintenance work as well as prodvides technical procedures as a reference for
the repairer, driver, technical personnel and professional manager.
Continuing enrichment and improvement of the manual may result changes to it, however the contents and
specifications are up to the minute. Defects or errors may occur in the manual, whenerver a question arises regarding
this manual, please consult us.
Final authority for the interpretation of this manual belongs to Great Wall Motor Co., Ltd.

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Model GW 4D28 diesel engine

Service Manual
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Maintenance documents
Mechanical system
4D28 engine
Fuel system
Cooling system
Starting system
Charging device
Exhaust system

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Maintenance documents-Fault diagnosis and troubleshooting

IN-1

Maintenance documents
Page
Fault diagnosis and troubleshooting ...........................
Main data and specifications .......................................
Maintenance standard .................................................
Maintenance work .......................................................
Fault diagnosis and troubleshooting ...........................
Special tools ................................................................

IN-2
IN-11
IN-13
IN-15
IN-23
IN-31

IN

IN-

Maintenance documents-Fault diagnosis and troubleshooting

Fault diagnosis and troubleshooting

1.Difficult to start the engine
Examination

Causes

Corrections

Contact failure of the storage battery terminals because of

oxidization corrosion.

Clean and refasten the terminals of storage battery.

Uncharged or uncharged sufficiently of the storage battery

Charge or replace the storage battery.

Loose or rupture of the generator belt

Adjust or replace the generator belt

Failure of the starter switch or the relay

Replace the starter switch or the relay

Failure of the electromagnetic switch or the relay

Repair or replace the electromagnetic switch.

1. The starter does not work

Storage battery
Fuse

Starter switch
Starter

Short-circuit or damage of the fuse

Starter failure

Replace the fuse

Repair or replace the starter.

2. The starter works but the engine can not rotate

Storage battery

Starter

Contact failure of the storage battery terminals because of

oxidization corrosion.

Clean and refasten the terminals of storage battery.

Uncharged or uncharged sufficiently of the storage battery

Charge or replace the storage battery.

Loose or rupture of the fan

Adjust or replace the fan belt

Pinion damage

Replace the pinion.

Failure of the electromagnetic switch

Repair or replace the electromagnetic switch.

Seizing or other damage of the piston or crankshaft bearings

Repair or replace related parts

The brush damaged or its spring too soft

Engine

Replace the brush or brush spring

3. The engine runs but can not ignited to start

Engine stop
mechanism

Damage of fuel shut-off electromagnetic valve

Replace the fuel shut-off electromagnetic valve

Fuel did not flow into the injection pump

Fuel

Fuel pipe
system
Fuel filter

Fuel tank empty

Fuel pipes blocked or damaged, or fuel pipe joint loose
Overflow valve of fuel filter can not close

Fill in the fuel tank to full

Repair or replace the fuel pipes or refasten the fuel

joint
Repair or replace the overflow valve of fuel filter

Fuel filter elements blockage

Replace the fuel filter elements

Fuel system

Air in the fuel system

Let air in the fuel system out

Fuel delivery
pump

Failure of the fuel delivery pump

Repair or replace the fuel delivery pump

Fuel flows into the injection pump

Fuel
Fuel system
Injector

Injection pump

Fuel type incorrect

Use qualified fuel

water exists in the fuel system

Replacement fuel

Air in the fuel system

Let air in the fuel system out

Injector seized

Replace the injector

Injection starting pressure too low or bad atomization of the

injector

Adjust or replace the injector

Motion failure of injection pump control rack

repair or replace the fuel delivery pump control rack

Delivery valve damaged causing fuel drops back after injection

Replace the delivery valve

Injection pump plunger damaged or blocked

Replace injection pump plunger coupling parts

Seizing or other damage of injection pump driving shaft

Replace the driving shaft

Injection pump governor spring blocked

Replace the injection pump governor spring

Maintenance documents-Fault diagnosis and troubleshooting

Examination

Causes

IN-

Corrections

4. Fast startup system

Preparations:

1.Disconnect lead socket joint of the temperature switch.

2.Determine if the preheating plug is switching
(a)Ensure the starting switch is opened
(b)Connect the cylinder wall and any preheating plug with a voltmeter
(c)Turn the starting switch to close position.
If the preheating plug is switching, the voltmeter will display voltage (12V)
If the voltmeter finger does not move, it means that the preheating plug is not switched
3.Failure repair

The preheating plug is switching

The indicating light of the
preheating plug is not on
Fast starting timer

The indicating light of the

preheating plug is on for 0.3
second

The indicating light of the

preheating plug is on for 3.5
second

temperature switch

Preheating plug connection

Indicating light bulb damage

Replace the bulb

Fast starting timer damage

Replace the fast starting timer

Fast starting timer damage

Replace the fast starting timer

Turn the starting switch from start back to

close after the engine has been started, if
the preheating plug relay keeps closing for
less than 14 seconds, then it indicates that the
fast starting up timer is damaged.
Turn the starting switch from open
to close , if the preheating plug relay
keeps closing for less than 14 seconds,
then it indicates that the fast starting up
timer is damaged.
Temperature switch damage
Preheating plug not connected

The preheating plug is not connected

The indicating light of the Indicating light fuse broke
preheating plug is not on
Fast starting timer

The indicating light of the

preheating plug is on for 3.5
second

Fast starting timer damage

Preheating plug relay damage The

preheating plug is not switching when
the starting switch turns from open to
close.
Preheating plug relay wires damage

Damage of fuse or wires The preheating

plug is switching when the starting switch
turns from open to close.

Replace the fast starting timer

Replace the fast starting timer

Replace the temperature switch

Replace the preheating plug

Replace the fuse

Replace the fast starting timer
Replace the preheating plug

Repair or replace the wires

Replace the fuses or wires

2.Unstable idle speed

Examination

Causes

Corrections

Idle speed system

Idle speed improper adjustment

Adjust the idle speed

High idle speed controlling

apparatus

High idle speed controlling apparatus

damage

Repair or replace the high idle speed

controlling apparatus

Throttle valve control

system

Throttle valve control system damage

Repair or replace the throttle valve control

system

Fuel system

Fuel filter

Fuel leakage of blockage of the fuel

system

Repair or replace the fuel system

Air in the fuel system

Let air in the fuel system out

Water in the fuel system

Replace fuel

Fuel filter elements blockage

Replace the fuel filter elements

Maintenance documents-Fault diagnosis and troubleshooting

IN-
Examination

Causes

Corrections

Delivery pump

Delivery pump damage

Repair or replace the fuel delivery pump

Fuel sprayer

Injection starting pressure too low or bad

atomization of the oil sprayer

Adjust or replace the sprayer

Injection pump

Fuel sprayer seized

Replace the fuel sprayer

Delivery valve damaged causing fuel oil

drops back after injection

Replace the delivery valve

Fuel injection insufficient

Adjust injection quantity

Adjustment of injection timing improper

Adjust injection timing

Idle spring damaged

Replace the idle spring

Governor control rod damaged

Improper adjustment of adjuster valve

Plunger spring failure

Plunger wear
Cam wear

Repair or replace the governor control rod

Adjust or replace the adjuster valve
Replace the plunger spring

Replace the plunger coupling parts

Replace the cam.

Air valve clearance

Improper adjustment of air valve clearance

Adjust the air valve clearance

Compressing pressure

Damage of the cylinder cover gasket

Cylinder bush wear
Piston ring adhesion

Replace related parts

3.Power insufficient
Examination

Causes

Corrections

Air filter

Air filter elements blockage

Clean or replace the air filter elements

Fuel oil filter

Fuel filter elements blockage

Replace the fuel filter elements

Fuel oil

Oil sprayer
High pressure oil pipe
Delivery pump

Water in the fuel

Sprayer seized

Injection starting pressure too low or bad

atomization of the sprayer

Adjust or replace the sprayer

Replace the high pressure pipe

Incorrect adjustment of injection timing

Incorrect adjustment of injection timing

Delivery pump damage

Repair or replace the delivery pump

Plunger wear

Plunger wear

Cam wear

Incorrect adjustment of injection timing

Plunger wear

Speed adjustment spring too soft

Air valve clearance

Replace the sprayer

Damage or blockage of the high pressure oil

pressure

Speed adjustment spring too soft

Injection pump

Replace fuel

Cam wear

Improper adjustment of air valve clearance

Speed adjustment spring too soft

Cam wear

Incorrect adjustment of injection timing

Plunger wear

Speed adjustment spring too soft

Cam wear

Adjust the air valve clearance

Compressing pressure

Damage of the cylinder cover gasket

Cylinder bush wear
Piston ring adhesion

Replace related parts

Air valve spring

Air valve spring too soft or rupture

Replace the air valve spring

Seal of full load adjustment

screws

Screw seals has been damaged or improperly

adjusted

Adjust and reseal the adjustment screws

exhaustion system

Exhaustion system blockage

Clean exhausting pipes

Maintenance documents-Fault diagnosis and troubleshooting

IN-

4.Fuel consumption too large

Examine

Causes

Fuel system

Fuel leakage

air filter

Air filter elements blockage

Idle speed
Valve clearance
Compressing
pressure

Adjust the idle speed

Improper adjustment of valve clearance

Adjust the valve clearance

Damage of the cylinder cover gasket

Cylinder bush wear Piston ring adhesion

valve spring

Repair or change the according spare part of

fuel system
Clean or replace the air filter elements

Improper adjustment of the idle speed

Injection starting pressure too low of the

injector

Oil sprayer

Corrections

Valve spring too soft or rupture

Adjust or replace the injector

Replace related parts

Replace the valve spring

5.Engine oil consumption too large

Examine

Causes

Engine Oil

Engine oil designation incorrect

Replace engine oil

Leakage of engine oil from the oil seal and/

or the gasket

Replace the oil seal and/or gasket

Engine oil overplus

Oil seal and gasket

Air ventilation port
Air intake valve,
exhaust valve

Correction

Air ventilation port blockage

Wear of the air intake valve, exhaust valve

and valve seat cone surfaces

Calibrate engine oil liquid surface

Clean the air ventilation port

Replace the air intake valve, exhaust valve

and the valve guide pipe, grind the cone
surface of the valve seat.

6.Engine overheat
Examine

Causes

Correction

Cooling water

Shortage of cooling water

Supplement of cooling water

Fan belt

Loose or rupture of the fan inducing

slipping

Replace the fan belt

Fan clutch

Engine oil leakage from the fan clutch

Radiator
Water pump

Radiator cover damage or radiator core

blockage

Replace radiator cover or clean the radiator

core

Cylinder cover gasket damage causes

cooling water leakage

Replace the gasket

water pump damage

Cylinder cover gasket

Thermostat
Cooling system
Oil injection timing

Replace the fan clutch

thermostat damage
Cooling system blockage with foreign
matters
oil injection timing incorrect

Repair or replace the water pump

Replace the thermostat

Cooling system blockage with foreign
matters
Adjust oil injection timing

7. White smoke arises from the engine exhaustion fume

Examine
Cooling water

Causes
Shortage of cooling water

Correction
Supplement of cooling water

Injection timing

Injection timing lag

Damage of the cylinder cover gasket
Cylinder bush wear
Piston ring adhesion
Valve oil seal damage
Wear or the valve rod or valve guide pipe

Adjust oil injection timing

Fuel

Compressing pressure
Oil seal of the air intake
valve, exhaust valve

Water in the fuel

Replace fuel

Replace related parts

Replace the valve oil seal or valve and valve
guide pipe

Maintenance documents-Fault diagnosis and troubleshooting

IN-

8.Smoke arises from the engine

Examine
Air filter
Injector
Injection timing
Injection pump

Causes
Air filter elements blockage

Injection starting pressure too low or bad atomization

of the injector
Injection timing incorrect
Delivery valve damaged causing fuel drops back after
injection
Injection overplus

Correction
Clean or replace the air filter elements
Adjust or replace the injector
Adjust oil injection timing
Replace the delivery valve
Adjust oil injection quantity

9.Engine oil pressure insufficient

Examination

Causes

Corrections

Engine oil

Engine oil designation incorrect

Engine oil insufficient

Replace engine oil

Supplement engine oil

Engine oil pressure gauge

or assembly pressure
gauge indicating light

Damage of engine oil pressure gauge or assembly

pressure gauge indicating light

Repair or replace engine oil pressure gauge or

assembly pressure gauge indicating ligh

Engine oil filter elements blockage

Replace the engine oil filter elements

Safety valve blocked or by-pass valve spring too soft

Replace the safety valve or by-pass valve

Engine oil pump filter screen blocked

Clean the engine oil pump filter screen

Camshaft and its bearings wear

Replace the rockshaft bearings

Engine oil filter

Safety valve or by-pass
valve
Engine oil pump
Rockshaft
Camshaft

Crankshaft and bearing

Relate parts wear of the engine oil pump

Camshaft and its bearings wear

Crankshaft and its bearings wear

Replace related parts of the engine oil pump

Replace the camshaft and its bearings wear

Replace the crankshaft and its bearings wear

10. Abnormal noise from the engine

Examination

Causes

Corrections

1.Engine knock

Examine if the engine has been preheated before failure examination.

Fuel

Fuel designation incorrect

Replace fuel

Injector

Injection starting pressure too low or bad atomization

of the injector

Adjust or replace the injector

Injection timing

Improper injection timing

Adjust oil injection timing

Damage of the cylinder cover gasket

Piston ring breakage

Replace related parts

Exhaust pipe

Exhaust pipe joint loose

Exhaustion pipe breakage

Tighten the exhaust pipe joints

Replace the exhaust pipe

Injector and/or preheating

plug

Injector and/or preheating plug loose

Tighten and fasten the injector and/or

preheating plug
Replace the washer

Exhaust manifold

Exhaust manifold loose

Tighten the exhaust manifold

Cylinder cover gasket

Damage of the cylinder cover gasket

Replace the cylinder cover gasket

Fan belt
Cooling fan

Fan belt slack

Cooling fan loose

Readjust tension of the fan belt

Fasten the cooling fan

AC electric generator or
vacuum pump

Damage of AC electric generator or vacuum pump

Repair or replace the AC electric generator or

vacuum pump

Compressing pressure

2.Gas leakage noise

3.Continuous noise

Water pump bearing

Valve clearance

Wear or damage of the water pump bearings

Improper adjustment of valve clearance

Replace the water pump bearings

Adjust the valve clearance

Maintenance documents-Fault diagnosis and troubleshooting

Examination

Causes

IN-

Corrections

4.Flapping noise
valve clearance

Improper adjustment of valve clearance

Adjust the valve clearance

Flywheel

Flywheel bolts loose

Fasten flywheel bolts

rockshaft

crankshaft and/or thrust

bearing

Rockshaft bearings wear

Wear of crankshaft and/or thrust bearing

Replace the rockshaft bearings

Replace the crankshaft and/or thrust bearing

crankshaft and/or connecting

Wear of crankshaft and/or connecting rod bearing
rod bearing

Replace the crankshaft and/or connecting rod

bearing

Piston and cylinder casing

Replace the piston and cylinder casing

Connecting rod bushing

and piston pin

Damage or wear of the connecting rod bushing

and piston pin
Wear or damage of piston and cylinder casing

Replace the connecting rod bushing and piston

pin

11. Engine cooling failures

Examination

Causes
Shortage of cooling water

Supplement of cooling water

Loose or rupture of the fan inducing slipping

Replace the fan belt

Constant temperature device damage

Radiator damage or radiator core blockage

Engine overheat

water pump damage

Cylinder gasket damage causes cooling water
leakage
thermostat damage
Cooling system blockage with foreign matters
Injection timing incorrect

Exhaustion system blockage

Injection overplus

Engine overcooling

Preheating time too

long of the engine

Corrections

Damage of the cylinder cover gasket

Too low of the engine oil liquid surface or engine
oil unqualified

thermostat damage
thermostat damage
Constant temperature device damage

Replace the constant temperature device

Replace radiator cover or clean the radiator core
repair or replace the water pump
Replace the cylinder gasket
Replace the thermostat

Clean the cooling system

Adjust oil injection timing

Clean exhausting system

Adjust oil injection quantity

Replace the cylinder cover gasket

Supplement or replace engine oil
Replace the thermostat
Replace the thermostat

Replace the constant temperature device

Maintenance documents-Fault diagnosis and troubleshooting

IN-

Examine if the storage battery is normal and then diagnose as follow:

starter do not rotate

Examine the storage battery

Storage battery failure or life

replace the storage battery

Storage battery is normal

Examine the wiring terminal

Interruption of terminals

Terminals connection is normal

Clean the storage battery terminals and

reconnect them

Examine the starter or its switch

There is any failure

Repair or replace
Switch on head light and starter switch

The head light is not bright or too dark

The head light is bright

(a) Storage battery charged insufficient

(b) Winding short circuit of the starter
(c) Starter parts failure

(a)
(b)

(c)

open circuit of the starter

Winding open circuit of
the starter
Starter switch failure

Maintenance documents-Fault diagnosis and troubleshooting

IN-

Engagement failure of the pinion and gear ring

When the starting switch turns to start position,

examine if there is voltage on the electromagnetic
switch terminals

Yes

No
or

Severe wear of the

pinion and gear ring
repair or replace the
starter, replace the
gear ring

Starter sliding
friction too large
repair or replace
the starter.

In this condition, examine if the voltage of restarting relay electromagnetic switch plug 3BW
is proper.
proper

improper

Break circuit between

the starting switch and
the electromagnetic
switch or connection
failure

Examine if there
is voltage on the
re-starting relay
starting switch plug.

repair

yes
Failure of starting
switch connection

Replace the starting

switch

no
Break circuit between
the starting switch and
the storage battery or
connection failure

repair

Maintenance documents-Fault diagnosis and troubleshooting

IN-10

Although the starting switch turns to start position,

but the electromagnetic switch does not work
when the starting switch turns to start position,
examine if there is voltage on

Yes

No

Examine the earthing cables

Examine if the instruments indicating lights are proper

All right
Or
sliding parts
of the pinion
can not move

Not good

Normal

Abnormal

Repair

Examine if the
terminals S are
closed between the
starting switch and
the electromagnetic

Failure of storage
battery and the
starting switch
connection

open circuit or burning

out of the electromagnetic
switch or wiring

Repair or replace the starter

Repair
Examine the
starter relay

Starter switch connection

failure

Examine the
clutch and the
starting switch

Replace the starting switch

The pinion and the gear ring engages but the engine can not run
Examine the earthing cable

Good

Bad
Repair or replace the earthing cable

Electric brush or
rectifier failure

Burnout of
electromagnetic
switch

Repair or replace the starter

Open circuit
or damage of
the excitation
wirings

Open circuit or
damage of the
armature coil

Pinion clutch
slipping

Maintenance documents-Main data and specifications

IN-11

Main data and specifications

Main data and specifications
Items

Engine model 4D28

Engine style
Combustion chamber style
Cylinder bush style
Cylinder number=cylinder diameterstroke
mm
Piston ring number
Total displacement ml
Compression ratio (for type I)
Compressing pressure kPa
Engine weight (net) kg
Fuel injection sequence
Fuel injection timing degree
Prescribed fuel brand
Idle speed r/min
Air intake valve mm
Valve space (cold condition)
Exhaust valve
mm
Inlet valve
mm
Valve space (hot condition)
Exhaust valve mm
Open (front of top dead centre)
degree
Inlet valve
close (rear of top dead centre)
degree
Open (front of bottom
dead centre)
degree
Exhaust valve
close (rear of top dead centre)
degree

Four strokes, valve-in-head, straight,

water cooling
style
Dry, chroming stainless steel tube
493102
Air ring: 2 Oil ring: 1
2771
18.2
3038
About 229
1342
Front of top dead centre 14
0# light diesel (-20#light diesel for cold
area)
750790
0.40
0.40
0.45
0.45
24.5
55.5
54
26

Lubricating system
Compound of pressure lubrication and
splashing lubrication
CD class diesel engine oil

Lubrication method
Prescribed engine oil brand
Engine oil pump type
Engine oil filter type
Engine oil capacity (including the engine oil filter)

Engine oil cooler type

Gear type
Full-flow, replaceable paper core
cartridge
6.67.1
Water cooling

Fuel system
Fuel pump type

Bosch distributing pump

Injector type

Hole type

Governor type

Open pressure of injector kPa

Mechanical (portion speed change)

Air filter type

18142
Paper filter cartridge and water
seperator
Dry paper filter cartridge

Starter specifications V-KW

122.8

Fuel filter type

AC electric generator specifications V-A

1250

Maintenance documents-Main data and specifications

IN-12

Cooling system
Cooling method

Closed forced circulation

Radiator type
Heat transfer

kcal/h

Heat transfer area

m2

Front face area

m2

Net weight

kg

Valve opening pressure

Capacity of coolant

kPa

Coolant pump type

Transmission ratio of the belt

Tube-band
71400
11.78

0.216
10.71

88118
3.1

Centrifugal wheel
1.2

Thermostat type

Valve opening temperature

Valve wide opening temperature

Total capacity of coolant

Wax pellet (with swing valve)

82
95
10

Startup system
Model
Items
Rating
Voltage
Output power
Startup time
Pinion teeth number

V
KW

sec

Rotation direction (from the pinion end)

Weight (about)

No load characteristic
Voltage/current
Rotation speed

kg

DENSOR
12
2.8
5
9

Clockwise
5.4

V/A
r/min

11.5/120 or less
4000 or more

Load characteristic
Voltage/current
Torque
Rotation speed

V/A
Nm

r/min

7.5/500 or less
13.0
1400 or more

Brake characteristic
Voltage/current
Torque

V/A
Nm

2.0/850 or less
15.7 or more

Charging appliance
Model
Items
Rated voltage

14

50

Rated current

Rotation direction (from the driving end)

Effective diameter of the pulley
Weight ( including pump)

HITACHILR150449B

Clockwise

mm

80

kg

6.0

Maintenance documents-Maintenance standard

IN-13

Maintenance standard
Engine mechanical system Unit: mm
Parts

Cylinder cover

Cylinder spring

Items
Flatness of the cylinder cover and outlet manifolds
mating surfaces.
Cylinder cover height
Angularity of cylinder cover bottom surface
Angularity of manifold mating surface
Combustion chamber clank block falling
Pressure exerted on the combustion chamber clank block
Free height
Verticality
Spring tension(N)
Installation height
Valve rod diameter
Air Inlet
Exhaust
Clearance between valve and valve guide pipe
Air Inlet
Exhaust
Valve guide pipe top height (measured from the cylinder
cover top plane)
Margin of the valve guide pipe
valve thickness
Air Inlet
Exhaust
Valve seat contact angle (degree)
Valve seat contact width
Air Inlet
Exhaust

Standard value Operating limit

0.05
920.05
0.05
0.05

44100-53900N

0.2

0.20
0.20
0.02

48.0
1.5
296
38.9

47.10
1.7
257.9

7.95
7.93

7.880
7.850

0.0390.069
0.0640.096
13.0
1.1

0.200
0.250

1.6

1.79
1.83
45

1.5
1.5
45

1.7
2.0

2.2
2.5

0.40

0.4

Axial gap
cam height
Journal diameter
Radial jumping
Camshaft bearing inner diameter

0.08
42.02
49.960.015
0.02

0.2
41.65
49.60
0.10
50.08

Camshaft oil gap

0.0250.085

0.12

Transverse
member

Outer diameter
Oil gap (between the rocker and the rockshaft)

12.9712.99
0.03

12.95
0.10

Radial direction
jump of the
rockshaft

The outer diameter of the rockshaft

The inner diameter of the rockshaft
Oil gap(between the crank arm the crankshaft)
Radial direction jump of the rockshaft

18.9819.00
19.03619.060
0.060.08
0.20

18.90
19.10
0.10
0.2

Engine oil pump

Oil gap
Between the pump and the gear wheel
Between the pump cover and the gear wheel

0.130.14
0.020.07

0.15
0.15

Valve and valve

guide pipe

Push rod

Camshaft

Degree of curvature

500+0.03

Notes

Can not be
reground

IN-14

Maintenance documents-Maintenance standard

Maintenance standard (Supplement)

Unit: mm
Parts

Crankshaft

Items

Standard value

Operating limit

Axial gap
Radial jumping of the main journal and the
connecting rod journal

0.10
0.05

0.30
0.08

Main journal diameter

70

69.91

Connecting rod journal diameter

Non-uniform wear of the main journal and
the connecting rod journal
Gap between the connecting rod journal and
the connecting rod bearing
Gap between the main journal and the main
bearing

53

52.90

0.05

0.08

0.0290.066

0.100

0.0350.080

0.110

Piston ring diameter

Piston gap (between the piston and the
cylinder bush)
Opening clearance of the piston ring
The first ring
The second ring
Oil ring
Piston, piston
pin, piston
ring and the
connecting
rod

Clearance of the piston ring

The first ring
The second ring
Oil ring
Piston pin diameter
Assembly Interference (between piston pin
and its seat hole)
(Cold state)
Connecting rod adjustment
Rod body linearity
Parallelization of two reducer holes
Gap between the piston pin and the
connecting rod bushing
Axial gap of the connecting rod
Oil gap
between the connecting rod journal and the
connecting rod reducer
Engine body top surface distortion
Cylinder hole diameter

Engine body

Cylinder bush projection quantity

Inner diameter of the cylinder casing
Inner diameter of the cylinder casing (rough
hole)

93

>93.024

0.0250.045

<0.025

0.200.40
0.200.40
0.100.30

1.5
1.5
1.5

0.0900.125
0.0500.075

0.15
0.15
30.970

31
0.0020.015

0.04

0.08
0.05
0.0080.020

0.20
0.15
0.050

0.230

0.35

0.0290.066

0.10

0.20

95
0.0-0.1
93.02093.060
95.01195.050

Notes

Maintenance documents-Maintenance work

IN-15

Maintenance work
Attention:
Normal maintenance works shall be carried by qualified
maintenance personnel.

Mark
Engine serial number
The serial number of the engine is stamped on the left side of
front end of the engine body.

Air filter
Cleaning methods vary for different filter cores.
Filter core blockage by dust
Turn filter core by hand, at the same time blow air into the filter
core, then the dust can be blown off.
The pressure of compressed air is 392 to 490kPa.
Attention

Do not hit the filter core onto other objects for the purpose
of cleaning; otherwise the filter core will be damaged.
Filter core blockage with carbon and dust
(a) Prepare original air filter core cleaning solution produced
by the Great Wall Car Company, and dilute it with water.
(b) Immerse the filter core into the cleaning solution for
about 20 minutes.

(c) Take out filter core from clearner,make it well cleaned,

water pressure should not exceed 274kpa

(d) Dry filter core in a well-ventilating site

Accelerate drying speed with electric fan.
Attention:
Do not accelerate drying process with compressed air or
naked flame,or, the filter core will be damaged.
Normally, a filter core can be dried for two to three days, and
then spare parts are needed at hand for temporary usage.
Pick the filter core out of cleaning solution and wash it with
flowing water.
The water pressure shall not more than 274kPa.
Lubricating system
Main oil filter ( paper type filter core)
replacement procedure

IN-16

Maintenance documents-Maintenance work

Lubricating system
Main oil filter ( paper type filter core)
replacement procedure
(a) Loose oil drain plug and drain oil.
(b) Tighten again the oil drain plug after several minutes.
(c) wist off used filter counter clockwise with filter wrench.
(d) Clean the mating surface of oil cooler.It can make new oil
filter assembly suitable.
(e) Apply a thin film of oil on the O-ring surface.
(f) Screw down the new oil filter until the O-ring and sealing
surface bind together.
(g) Screw down for 1.25 turns with filter wrench.
Filter wrench: 5-8840-0200-0
5-8840-0202-0
5-8840-0209-0
(h) Examine the oil level, add to the prescribed level if required.
0.7LOil filling capacity is 0.7L.
(i)

Start the engine and check if there is any leakage in the oil filter.

Fuel system
Replacement procedure of fuel filter
(a) Twist off used filter counter clockwise with filter wrench.
Filter wrench: 5-8840-0253-0(J-22700)

(b)

Clean the mating surface of the filter base plate.

It can make new fuel filter assembly suitable.

(c) Screw down new fuel filter until it can contact with the
sealing surface.
(d)

Screw down for 2/3 turns with filter wrench.

Filter wrench: 5-8840-0253-0(J-22700)

Maintenance documents-Maintenance work

IN-17

(e)

Loose the vent valve on top of the overflow valve of

injection pump.
(f) Start the injection pump until fuel flows out of the fuel filter.
(g) Retighten the vent plug.
(h) Start injection pump up and down several times and
check if there is any leakage of fuel.
Attention:
Original fuel filter produced by the Great Wall Car
Company is recommended.

water quantity indicator

of fuel water separator

Blowdown procedure of water separator.

When water content surpasses prescribed value, the indicating
lamp will light.
Drain water and other foreign material according to the following procedures.
(a) Park the car in a safe place.
(b) Open the outer cover of the engine and place a vessel
(capacity 0.2L) at the end of ethane hose under the drain

loose drain plug counter clockwise

plug of water separator.

(c) Loose drain plug counter clockwise for about 5 turns and
start injection pump up and down for about 10 times to
drain about 0.1L water.
(d) After drainage, tighten drain plug clockwise immediately and start the injection pump for several times.
(e)

Start the engine and check is there is any fuel leakage

from the water drain plug.At the same time, check if the
indicating lamp of water separator is off.

tighten drain plug clockwise

vent procedure of water separator.

(a) Loose the vent screw on top of the overflow valve of injection pump.
(b) Start the injection pump up and down
until fuel mixed with foam flows out of
vent screw.

Cooling system
Coolant liquid level
Inspect the coolant liquid level, fill the water overflow tank
of the radiator if required.If the coolant liquid level below
the mark
MIN

, examine carefully if there is any leakage

(c) Tighten vent screw.

of cooling system and fill in coolant until the coolant liquid

level reaches
MAX
.

(d)

Attention:

Start injection pump several times and

check if there is any leakage of fuel.

not overfill water overflow tank.

ver of watering orifice can only be opened when
absolutely necessary.
olant liquid level inspection shall always be carried
out when the engine is cold.

IN-18

Maintenance documents-Maintenance work

Mixing ratio of cooling water vs. anti-freezing liquid shall

always be determined according to the left diagram.

ice point (
)

long-acting coolant

mixing ratio


Inspection of cooling system

Mount the tester of the radiator water filling port onto the
radiator.
Increase the pressure of the cooling system to examine if there is
any leakage.
Attention:
The test pressure shall not surpass prescribed pressure.
The test pressure is 196kPa.
Radiator inspection
The water filling port cover of the radiator shall be designed to
maintain prescribed pressure in the cooling system
Examine if the design of water filling port cover of the radiator
meets the requirements with the tester of water filling port cover
of the radiator.
The water filling port cover must be replaced if the prescribed
pressure can not be maintained during the test.
The prescribed pressure of the water filling port cover of
radiator is:
Pressure valve: (88-118)kPa
Negative pressure valve (reference value): (1.0-3.9)kPa
Thermostat action test
(a) Immerse the thermostat into water totally.
(b) Heat water.
Stir water continuously to prevent thermostat from direct
heating.
(c) Check the original open temperature of the thermostat.
The original open temperature of the thermostat is 82
.
(d)

air compressor and power

turning pump driving belt

Check the wide open temperature of the thermostat

(a)

AC generator and
fan driving belt

Adjustment of drive belt

The wide open temperature of the thermostat is 95
.
Valve wide open lift range: 10mm.

Examine if there is any wear and damage of drive belt,

replace it if necessary.
(b) Examine the rate of tension, adjust it if necessary.
(c) Press the middle of the drive belt with 98N force and
examine the belt deflection.
Standard deflection: (8-12)mm.

Maintenance documents-Maintenance work

IN-19

Engine control
Examine the idle speed
(a)

Operate car hold-up brake and retard driving wheel.

(b) Set the gearbox in free position.

(c) Start the engine and warm it.
(d) Remove engine control pull wire from the control rod.
(e) Mount the revolution indicator onto the engine.
Examine the idle speed of the engine.
If the idle speed surpasses prescribed range, adjust it.
The idle speed of the engine: (750-590) r/min.
Adjust the idle speed
(a) Loose the idle speed adjustment locknut on the oil injection
pump.
(b) Adjust the idle speed to prescribed range with the idle speed
adjustment bolt.
(c) Lock the idle speed adjustment bolt with the locknut of idle
speed adjustment bolt.
(d)

Examine if the idle speed control pull wire has been pulled
tight (no relax).Remove the relaxed part (if any).

Adjustment of the throttle pull wire

(a) Loose the support bolts of throttle pull wire.
(b) Examine if the control button is in engine idle speed.
(c)

Set the throttle pull rod at fully-closed position, then strength

control pull wire along the direction of arrow to eliminate all
relax.

Adjustment of throttle control

(a) Loose locknut
(b)

Adjust height between the adjustment bolt and the base

plate.
Height shall be 18-28mm (SL).

(c)

Check if the throttle control is in the range of 5-10mm above

the throttle control dead block.

(d) Press the throttle control fully, examine if the engine speed
is maximum and if every joint operates steadily.
(e) The throttle control and injection pump pull rod should
easily return to their original position in their action range.
Adjustment of valve space
(a)

Turn the crankshaft until the top dead point line of the
crankshaft vibration damper aligns with timing pointer. At
this time, the piston either in the first cylinder or the fourth
cylinder is at the top dead point of compression travel.

IN-20

Maintenance documents-Maintenance work

(b)

Examine if the support nuts of oscillating beam shaft loosed.

Screw down any loosed support nuts of oscillating beam
shaft before valve space adjustment.
Tighten torque: 54N
m

(c)

Examine the space between the push beams of air intake valve
and exhaust valve in the first cylinder.
If there is any space between the push beams of air intake valve
and exhaust valve in the first cylinder, then the piston in the first
cylinder is at top dead point of compression travel.
If the push beams of air intake valve and exhaust valve in the
first cylinder are compressed, then the piston in the fourth
cylinder is at top dead point of compression travel.
Adjust the space of the valves in the first cylinder or the fourth
cylinder, when the corresponding cylinder is at top dead point
of compression travel
Valve space (cold condition) 0.4mm

(d)

Loose each valve space adjustment bolt as shown in the

diagram.

(e)

Insert the feeler with thickness complied with the space

between air intake valve and exhaust valve into the middle
of oscillating beam and valve.

(f)

Turn the adjustment bolts of valve space until there is light

resistance on the feeler.

(g)

Screw down the locknut tightly.

(h) Turn the crankshaft for 360 degree.

(i) Realign the timing mark on the pulley of crankshaft vibration damper with the top dead point scratch.
(j)

Adjust the space of other valves as shown on the diagram.

Adjustment of oil injection timing

(a) Set the piston in the first cylinder at top dead point.
(b) Dismount the plug on top of the oil injection pump distributor.
(c) Remove wax type cold start device with screwdriver hand lever.
(d)

Mount a micrometer gauge and prepress to 1mm.

(e)

Align the dead point mark on the pulley of crankshaft

vibration damper to the point 45 degree from the top dead
point indicating hand.

IN-21

Maintenance documents-Maintenance work

Set the micrometer gauge on
0
position.

Measurement device: 5-8840-0145-0
(g) Turn the crankshaft right and left slightly, examine if the
pointer of the micrometer is at the position of
0
.
(h) Turn the crankshaft along operating direction and read out the
measurement device when the crankshaft is at the top dead point.
The original timing reading is 0.5mm.
(i) If the oil injection surpasses prescribed range, continue to
finish the next procedure.
(j) Loose locknuts and support bolts of oil injection pump.
(f)

(k)

Adjust the assembly angle of oil injection pump.

If set forward the oil injection timing, move the oil injection
pump to the engine.

If retard the oil injection timing, move the oil injection pump
away from the engine.

Screw down the retaining nuts, adjusting bolts and oil injection

pump distributor top plug to prescribed torque.

Screw down torque of oil injection pump retaining nuts is: 24N
m
Screw down torque of oil injection pump adjusting bolts is: 19N
m
Screw down torque of oil injection pump distributor top plug is:
54N
m
Attention: new copper carrier ring must be used when
assemble distributor top plug.
Compressing pressure measure
(a)
(b)

Start the engine and let it operate in idle speed until the coolant
temperature reaches 70-80
.
Remove the following parts:
All of the preheating plugs

Fuel shutoff magnet coil plug board.

Fuse of QOS(quick start system) on the plug board.

(c)

Mount the joint and pressure gauge into the preheating plug
hole of the first cylinder.
Compressing pressure gauge
Belt joint: 5-8840-2008-0-(J-29762)

Joint: 5-8531-7001-0
(d) Drive the engine with the starter and record the pressure gauge
reading.
When the speed is 200r/min, the operating pressure is
Standard
2942

Limit
2157

kPa

IN-22

Maintenance documents-Maintenance work

(e)

Repeat procedure (c) and procedure (d) for the other

cylinders.
If the measurement value is less than prescribed value,
refer to section Fault diagnosis and debugging in this
manual.

Fast start II system

Fast start system examination procedure
(a) Disconnect the water temperature sensor wires of
thermostat.
(b) Turn the starting switch to close position.
If the fast start II system operates regularly, then the
preheating relay will give out minute static electricity
disturbance sound after then switch turns on.
(c)

Measure the voltage of preheating plug end with multimeter after the start switch turns to close position.
The voltage of preheating plug end is about 11V.

IN-23

Maintenance documents-Fastening torque

Fastening torque
Cylinder cover shield
Rockshaft assembly
Cylinder cover

13

54

15

N
M

:prescribed torque

The first step

The second step

49

60-75

The third step

60-75

IN-24

Maintenance documents-Fastening torque

Crankshaft. Main bearing cover .Connecting rod bearing cover.Crankshaft vibration absorber pulley .Flywheel. Oil bottom casing

The first step

The second step

59

60-90

13

83

167

19

206

40
19
N
M

:prescribed torque

IN-25

Maintenance documents-Fastening torque

Timing gear Timing gear chamber Back plate of the machine body
19

19

19

76
82

19

19

N
M

:prescribed torque

IN-26

Maintenance documents-Fastening torque

Cooling system and lubricating system

20
8

19

29

29
19

19

25
19
19

N
M

:prescribed torque

IN-27

Maintenance documents-Fastening torque

Air inlet manifold Exhaust manifold Front exhaust pipe

19

26

50

67

40

N
M

:prescribed torque

IN-28

Maintenance documents-Fastening torque

Engine electrical system

19

22

23

40

preheating plug

85

cold area excluded

19
85
N
M

:prescribed torque

IN-29

Maintenance documents-Fastening torque

Engine fuel system

37

29
19

19
64

55

29
55
N
M

:prescribed torque

IN-30

Maintenance documents -Fastening torque

Installation support of the engine

82

40

N
M

:prescribed torque

EM-1

Mechanical system
Page
Cylinder cover .............................................................
Crankshaft shaft assembly ..........................................
Air valve assembly ......................................................
Camshaft and erection pole ........................................
Crankshaft ...................................................................
Piston and connecting rod assembly ..........................
Engine oil pump assembly ..........................................
Engine body ................................................................

EM-2
EM-6
EM-8
EM-13
EM-19
EM-28
EM-34
EM-37

EM

EM-2

Mechanical system-Cylinder cover

Cylinder cover

Disassembly procedure
1. thermostat body assembly
2. oil sprayer body
3. preheating plug and plug link plate
4. rockshaft assembly
5. push rod
6. cylinder cover

Reassembly procedure
Reassemble according to the reverse
procedure of disassembly.

Attention:

When disassembly, the parts of air valve assembly shall
be collected in a place and marked with identification sign
so that they can be restored to their original location.

Compression test shall be carried out and its result shall
be recorded before remove cylinder cover from the engine
and disassemble air valve mechanism.

Disassembly
1.
2.

Thermostat body assembly

Oil sprayer body
(a) Dismount press plate bolts of oil sprayer.

(b)

Dismount the oil sprayer body and press plate all in

together with oil sprayer body detacher and slide hammer.
Oil sprayer detacher: 5-8840-2034-0
Slide hammer: 5-8840-0019-0

3.
4.

Preheat plug and plug link plate

Rockshaft assembly

5.

Pushing bar

EM-3

Mechanical system-Cylinder cover

6.

Cylinder cover
Loose the cylinder cover bolts gradually for several times
according to the order number shown in the diagram, each for
a little.
Attention:
If you fail to do so, the bottom surface of the cylinder
cover will be damaged.

Clean up
1.
2.

Cylinder cover bolt

Cylinder cover
Clean up all of the oil dirt, carbon fume and built-up carbon
until the metal local color appears.
Do not use electric driven metallic wire brush for any gasket
sealing surface.

Inspection and maintenance

4D28

Parts must be adjusted, repaired or replaced when excess wear

or damage is found in examination.
(1) Examine if there is any leakage, corrosion or gas blow by
in the gasket of cylinder cover.
If the gasket fails, the results shall be determined:
(a) Improper assembly
(b) Cylinder cover loose or distorted
(c) Screw down torque of cylinder cover bolts insufficient
(d) Engine body surface distorted
(2) Examine if there is any damage or elongation of cylinder
cover bolts or if there is any damage of cylinder cover
because of improper use of tools.
Notes:
Suspicious bolts must be replaced.
(3) Examine if there is any crack on the cylinder cover,
especially around the air valve seat and exhaust opening.
(4) Examine if there is any corrosion on the bottom surface
of the cylinder cover and if there is any sand inclusion and
porosity inner the cylinder cover.
Notes:
Do not try to weld up the cylinder cover. Replace immediately
if the cylinder cover is damaged.
(5)

Examine the flatness of the cylinder cover plane and

inlet/outlet manifolds mating surfaces.
these surfaces can be mended through grinding.
If surface roughness exceeds prescribed limit, the surface
shall be grinded to meet the technical requirements
It shall be replaced if the surface roughness exceeds
technical requirements much.
mm

Angularityy of the cylinder boottom surface

The heiight of the cylinder cover

Staandard
0.05 or smaller
92

Limit
0.20
991.55

EM-4

Mechanical system-Cylinder cover

(6) Examine the mating surface of water jacket sealing plugs.
(7) Measure angularity of the mating surface between the
exhaust manifold and the cylinder cover with a ruler and a
feeler gauge.
The mating surface shall be reground if the measurement value
is between the prescribed limit value and standard value.
The exhaust manifold must be replaced if the measurement value
exceeds the prescribed limit value.
Angularity of mating surface between the exhaust manifold and
the cylinder cover .
mm
Standard
0.05 or smaller

Limit
0.20

Reassembly

1. Cylinder cover
(1) Assemble valve seat (cold-press assembly)
(a) Mount the accessory
(its outer diameter less than the
valve seat) onto the valve seat
.
Attention: the mating surface with the valve seat must be
the smooth surface of the accessory.
(b) Press the accessory gradually with table press to force the
valve seat in position.
Attention:
The force exerted by the table press should not in excess,
or the valve seat will be damaged.
(c) Measure the installation height of valve guide pipe from
one side of the cylinder cover top surface.
Height H (reference): 13mm.
Attention:
If the valve guide pipe has been disassembled, the valve
and valve guide pipe must be replaced as a pair.
(2)

(3)
(4)
(a)
(b)

Valve
Smear machine oil on the outer diameter of the valve rod
before valve installation.
Spring washer
Air valve oil seal
Mount new oil seal onto the valve guide pipe.
Pull in it with special tool.
Valve oil seal erecter: 5-8840-2033-0

(5) Air valve spring

(a) Mount valve spring onto the spring washer.
(b) Mount valve spring seat onto the spring washer.
Notes:

The end of the valve spring applied with paint shall be
downward.

Introduce compressed air from the preheating plug
hole to the cylinder forcing valve in position.

Mechanical system-Cylinder cover

EM-5

(6) Air valve door lock

(a) Press the valve spring in position with spring compressor.
(b) Mount the air valve door lock into the valve spring seat.
(c) Tap around of the door lock with rubber hammer.
Valve spring compressor: 9-8523-1423-0
J-29760

2.

Push rod

3.

Rockshaft assembly
Screw down the fastening bolts of the rockshaft assembly to
prescribed torque.
Tighten torque: 54N
m.

4.

Preheating plug and plug link plate

Screw down the preheating plug to prescribed torque.
Tighten torque: 23N
m.

5.

oil sprayer body

(a) Mount the oil sprayer sealing ring
and O-ring
onto
the oil sprayer body
.

Ensure that the O-ring clings the O-ring groove of oil

sprayer.
(b) Apply machine oil into the hole on the cylinder cover to
which oil sprayer body is mounted.
(c) Mount the oil sprayer together with its clamp plate

onto the cylinder cover.
Screw down the clamp plate bolts of oil sprayer to
prescribed torque.
Tighten torque: 37N
m
6. Thermostat body assembly
Screw down the fastening bolts of the thermostat body assembly to prescribed torque.
Tighten torque: 19N
m

EM-6

Mechanical system-Rockshaft assembly

Rockshaft assembly

Disassembly procedure
1. rockshaft assembly
2. rockshaft elastic collar
3. rocker
4. rockshaft support
5. rocker
6. rockshaft spring
7. rockshaft

Reassembly procedure
Reassemble according to the reverse
procedure of disassembly.

Disassembly
1.
2.
3.
4.
5.
6.
7.

Rockshaft assembly
Rockshaft elastic collar
Rocker
Rockshaft support
Rocker
Rockshaft spring
Rocker

Inspection and maintenance

Parts must be adjusted, repaired or replaced when excess wear
or damage are found in examination.
Oil film clearance
(a) Measure the inner diameter of the rockshaft with vernier
caliper and inner diameter dial gauge.
The rockshaft must be replaced if the measurement value
exceeds the prescribed limit value.
Diameter of rockshaft
mm
Standard
19.036

(b)

Limit
19.100

Measure the outer diameter of the rockshaft with spiral

micrometer at the oscillating position of the rocker.
The rocker must be replaced if the measurement value
exceeds the prescribed limit value.
Diameter of rockshaft
mm
Standard
18.98-19.00

Limit
18.90

Clearance between the rocker and the rockshaft

Standard
0.06-0.08

Limit
0.10

mm

Mechanical system-Rockshaft assembly

EM-7

(c) Examine the oil hole of the rocker to ensure it not blocked.
Sweep the oil hole of the rocker with compressed air if
necessary.

Rocker correction

Examine step abrasion
and scoring
condition of the

contact surface of the rocker top valve rod
If there is any light step abrasion or scoring on the contact

surface, rub it with oil stone.

If the step abrasion or scoring is severe, the rocker must be
replaced.

Axial/radial direction jump of the rockshaft

(a) Put the rockshaft on the V-type block.
(b)

Measure the radial jump in the middle of the rockshaft

with dial gauge.
If the radial jump is light, it can be corrected with table press.
The rocker must be replaced if the radial jump of rockshaft exceeds the prescribed limit value.
Limitation: 0.2mm

Reassembly
1.

Rockshaft
(a) Apply a thin film of oil on the rockshaft.
(b) Mount the rockshaft, rocker, rockshaft spring and rockshaft support onto the cylinder cover together.

2.

Rockshaft spring

3.
4.

Rocker
Rockshaft support

5.
6.

Rocker
Rockshaft elastic collar

7.

Rockshaft assembly
(a) Assemble the rockshaft assembly onto the cylinder cover.
(b) Screw down the support bolts of the rockshaft to prescribed torque according to the procedure shown in the
diagram.
Tighten torque: 54N
m

EM-8

Mechanical system-Air valve assembly

Air valve assembly

Disassembly procedure
1. rockshaft assembly
2. air valve door lock
3. air valve spring
4. air valve
5. air valve oil seal
6. air valve guide pipe

Reassembly procedure
Reassemble according to the reverse procedure of disassembly.

Disassembly
1.

Rrockshaft assembly

2.

Air valve door lock

Press the valve spring and dismount the air valve door lock
with special tool.

3.

Valve spring compressor: 9-8523-1423-0
J-29760

Air valve spring

4.
5.

Air valve
Air valve oil seal

6.

Air valve guide pipe

Valve guide pipe: 9-8523-1212-0

Inspection and maintenance

Parts must be adjusted, repaired or replaced when excess wear
or damage is found in examination.

Air valve spring

Attention:
Visually examine the air valve springs, replace them if
1.

there is any significant abnormal abrasion

Free height
Measure the free height of the spring,
The spring must be replaced if the measurement value is under
the prescribed limit value.
Free height

mm
Standard
48.0

Limit
47.1

EM-9

Mechanical system-Air valve assembly

2.

Verticality
(a) Measure the verticality of the air valve spring with a
right-angle steel ruler.
(b) The air valve spring must be replaced if the measurement
value exceeds the prescribed limit value.
Limitation: 1.7mm

3.

Spring tension
(a) Compress the spring to its installation height with a
spring testing instrument.
Measure the tension of the compressed spring.
(b) The air valve spring must be replaced if the measurement
value is less than the prescribed limit value.
Spring tension
N
m
Installation
height 38.9mm

Standard
296.2

Limit
257.9

Air valve guide pipe

Attention:

Be careful not to destroy the contact surface of air valve
seat when cleaning carbon deposition on the air valve
head.

Examine carefully abrasion and abnormal wear on the
air valve rod.

The air valve and air valve guide pipe must be replaced
as a pair if there is any above mentioned condition.
1.

Air valve guide pipe gap

(a) Measure the outer diameter of air valve rod with a spiral
micrometer.
The air valve and air valve guide pipe must be replaced
as a pair if the outer diameter of air valve rod exceeds
Prescribed limit.
Air valve rod diameter
mm
Air intake valve
Exhaust valve

Standard
7.946-7.961
7.921-7.936

Limit
7.880
7.850

(b) Measure the inner diameter of air valve guide pipe with
a micrometer.
(c) Measured air valve guide pipe inner diameter subtracts
measured air valve rod outer diameter.
The air valve and air valve guide pipe must be replaced
as a pair if the difference exceeds prescribed limit.
Air valve guide pipe gap
mm
Air intake valve
Exhaust valve

Standard
0.039-0.069
0.064-0.096

Limit
0.200
0.250

EM-10

Mechanical system-Air valve assembly

2.

Replace the air valve guide pipe

(a) Knock the air valve guide pipe out of the combustion
chamber use special tool.
Valve guide pipe replacer: 9-8523-1212-0

(b) Coat the air valve guide pipe outer surface with engine oil.
(c) Mount new air valve guide pipe form one side of cylinder
cover top surface with special tool; examine installation
height of the air valve guide pipe.
Height H: 13mm
Valve guide pipe replacer: 5-8523-1212
Attention:
If the valve guide pipe has been disassembled, the valve
and valve guide pipe must be replaced as a pair.

Air valve
1.

Air valve thickness

Measure air valve thickness
The air valve and air valve guide pipe must be replaced as a pair
if the measured value is less than prescribed limit.
Air valve thickness
mm
Air intake valve
Exhaust valve

2.

Limit
1.50

Air valve subsidence

(a) Mount valve
onto the cylinder cover
.
(b) Measure air valve subsidence at the bottom surface of the
cylinder cover with depth meter or straight ruler and steel rule.
The air valve seat must be replaced if the measured value
exceeds the prescribed limit value.
Air valve subsidence
mm
Air intake valve
Exhaust valve

3.

Standard
1.79
1.83

Standard
0.73
0.70

Limit
1.28
1.20

Air valve contact width

(a) Examine air valve contact surface roughness and plainness.
The contact surface of the air valve shall be smooth.
(b) Measure air valve contact width
The air valve seat must be replaced if the measured value
exceeds the prescribed limit value.
Contact width
mm

Air intake valve

Exhaust valve

Standard
1.7
2.0

Limit
2.2
2.5

Mechanical system-Air valve assembly

EM-11

Air valve seat

1.

Air valve seat contact taper-face angle

(a) Measure the air valve seat contact taper-face angle
(b) The air valve, air valve guide pipe and air valve seat must
be replaced as a pair if the measured value exceeds
prescribed limit.
Standard value: 45

2.

Disassemble air valve seat

(a) Electric arc welding of periphery interior
of the air
valve seat
.
(b) Cool the air valve seat for several minutes.
This can cause the air valve seat to shrink so that the air
valve seat is easily to disassemble.
(c) Pry the air valve seat with a screwdriver to break it off.
Take care not to damage the cylinder cover
.
(d) Remove carbon deposit and other foreign matter from the
air valve seat installation hole of the cylinder cover.

3.

Air valve seat assembly

(a) Mount the accessory
(its outer diameter less than the
valve seat) onto the valve seat
.
Attention:
The accessories contact with the air valve with smooth
surface.
(b) Press the accessory gradually with table press
to force
the valve seat in position.
Attention:
The force exerted by the table press should not in excess,
or the valve seat will be damaged.

4. Air valve seat correction

(a) Remove carbon deposit from the air valve seat surface.
(b) Machine with air valve milling cutter (15
45
and 75

lade) to minimize scratching and other coarse surface so
that the contact width can restore standard value.
Air valve seat angle: 45

Attention:

Wipe off only scratching and coarse surface, do not wipe
off too much.

Take care not to cut off air valve surface area without
defections.
Use adjustable air valve miller cutter guide bar.
Sloshing of the air valve miller cutter guide bar in the air
valve guide pipe is not permitted.
(c) Coat grinding cream on the air valve seat surface.
(d) Insert the air valve into the air valve guide pipe.

EM-12

Mechanical system-Air valve assembly

(e) Knock the air valve up and down slightly and turn the air
valve at the same time to be fitted with the air valve seat.
(f)
(g)

Examine if the air valve contact width is proper.

Examine if the air valve seat surface can contact with
overall air valve circumference.

Reassembly
1.

Air valve guide pipe

(a) Coat the air valve guide pipe outer surface with engine oil.
(b) Mount a new air valve guide pipe from one side of
cylinder cover top surface with special tool.
Valve guide pipe replacer: 9-8523-1212-0

2.

Air valve oil seal

Mount the air valve oil seal with special tool.
Valve oil seal erecter: 5-8840-2033-0

3.
4.

Air valve
Air valve spring
Mount valve spring onto the spring washer.
The end of the spring applied with paint shall be downward.

5.

Air valve door lock

(a) Press the valve spring in position with spring compressor.
(b) Mount the air valve door lock and the valve spring seat.
(c) Tap around of the door lock with rubber hammer.
Valve spring compressor: 9-8523-1423-0
J-29760

6.

Rockshaft assembly
Screw down the fastening bolts of the rockshaft assembly to
prescribed torque.

Tighten torque: 54N
m

Mechanical system-Camshaft and transverse member

EM-13

Camshaft and transverse member

Disassembly procedure
1. cylinder cover assembly
2. flywheel
3. back plate of the machine body
4. oil bottom casing assembly
5. engine oil pump assembly
6. camshaft timing gear
7. camshaft thrust plate
8. camshaft
9. transverse member

Reassembly procedure
Reassemble according to the reverse
procedure of disassembly.

Disassembly
1.
2.
3.
4.
5.
6.

Cylinder cover assembly

Flywheel
Back plate of the machine body
Oil bottom casing assembly
Engine oil pump assembly
Camshaft timing gear
(a) Dismount the camshaft timing gear fixing bolts from the
camshaft.
Attention:
Fix the camshaft to prevent it turning.
(b) Pull camshaft timing gear
out with general purpose
puller
.
General purpose puller: 5-8521-0002-0
JKM-1034

(c) Disassembly the thrust plate
.

7. Camshaft thrust plate

8. Camshaft
9. Transverse member

Inspection and maintenance

Parts must be adjusted, repaired or replaced when excess
wear or damage are found in examination.

EM-14

Mechanical system-Camshaft and transverse member

Camshaft
1.

Camshaft axial clearance

Measure the camshaft axial clearance with a dial gauge.
This task must be carried out before disassembling camshaft
timing gear.
The thrust plate must be replaced if the axial clearance of
camshaft exceeds the prescribed limit value.
camshaft axial clearance
mm
Standard
0.08

2.

Camshaft outer diameter

Measure the camshaft outer diameter in two direction
and

with spiral micrometer.
The camshaft must be replaced if the measurement value is
under the prescribed limit value.
Shaft outer diameter
mm
Standard
49.945-49.975

3.

Limit
41.65

Camshaft radial jumping

(a) Put the camshaft on the V-type block.
(b) Measure the camshaft axial jumping with a dial gauge.
The camshaft must be replaced if the measurement value
exceeds the prescribed limit value.
Radial jumping
mm
Standard
<=0.02

5.

Limit
49.600

Cam height
Measure the camshaft height H with a micrometer.
The camshaft must be replaced if the measurement value is
under the prescribed limit value.
cam height
mm
Standard
42.02

4.

Limit
0.20

Limit
0.10

Camshaft bearing clearance

Measure the inner diameter of the camshaft bearing with an
inner diameter micrometer.
Camshaft bearing inner diameter
mm
Standard
50.00-50.03

Limit
50.08

Camshaft bearing clearance

Standard
0.025-0.085

mm
Limit
0.12

The camshaft bearing must be replaced if the camshaft bearing

clearance exceeds the prescribed limit value.

EM-15

Mechanical system-Camshaft and transverse member

Camshaft bearing
Disassemble camshaft bearing
(a) Dismount the bowl plug of machine body.
(b) Disassemble the camshaft bearing with bearing replacer.
bearing replacer: 5-8840-2038-0

Assemble camshaft bearing

(a) Align the oil hole on the bearing with that on the engine
body.
(b) Assemble the camshaft bearing with bearing replacer.
bearing replacer: 5-8840-2038-0

Transverse member
Visually examine if there is any spot corrosion, crack and other
abnormal conditions on the contact surface of the transverse
member and camshaft.
The transverse member must be replaced if any above mentioned occurs.
Refer to the left diagram

normal contact

crack

spot corrosion

abnormal contact

abnormal contact
Attention:

The transverse member surface is spherical, do not try to

grind the transverse member when repairing it with oil
stone or other similar tools.
The transverse member must be replaced if it is damaged.

Transverse member outer diameter

(a) Measure the outer diameter of transverse member
with a spiral micrometer.
The transverse member must be replaced if the
measurement value is under the prescribed limit value.
Transverse member outer diameter
Standard
12.97-12.99

mm
Limit
12.95

EM-16

Mechanical system-Camshaft and transverse member

(b) Measure the inner diameter of installation hole on the
transverse member, calculate for clearance.
The transverse member and/or engine body must be
replaced if the gap between the transverse member and its
installation hole exceeds the prescribed limit value.
Clearance between the transverse member and its installation hole mm
Standard
0.03

Limit
0.10

Reassembly
1.

Transverse member
(a) Apply machine oil on the surfaces of the transverse
member
and its installation hole
.
(b) Determine the transverse member according to the position
in disassembly (if the transverse member will be reused).
Attention:
The transverse member must be assembled before

camshaft assembly.
2.

Camshaft
(a) Smear the camshaft and its bearings with machine oil.
(b)

3.

Mount the camshaft onto the engine body.

Take care not to damage the camshaft bearings.

Camshaft thrust plate

Install the camshaft thrust plate onto the engine body and
screw down the camshaft thrust plate to prescribed torque.
Tighten torque: 18N
m

4.

Camshaft timing gear

(a) Mount the camshaft timing gear onto the camshaft.
The mark Y-Y on the timing gear must face outside.
(b)

Screw down the fastening bolts of the camshaft timing

gear to prescribed torque.
Tighten torque: 85N
m

Mechanical system-Camshaft and transverse member

EM-17

5.

Engine oil pump assembly

(a) Smear the oil pipe O-ring with engine oil and mount the
O-ring into its groove in the engine body.
(b) Install the engine oil pump assembly and the oil pipe onto
the engine body and screw down the fixing bolts to
prescribed torque.
Tighten torque: 19N
M
(c) Screw down the bush nuts to prescribed torque
Tighten torque: 25N
M

6.

Oil bottom casing assembly

(a) Oil the arc area of the fifth main bearing cover, groove
and timing gear chamber arc area with recommended
liquid sealant or the similar.

(b)

Mount the gasket back-lip into the groove in the fifth

main bearing cover.
(c) Ensure that the back-lip clings with the groove.
(d) Mount the oil bottom case onto the engine body.
(e) Screw down the fastening bolts of oil bottom case to
prescribed torque.
Tighten torque: 19N
m
7.

Back plate of the machine body

(a) Align the fix pinhole on the back plate with that on the
engine body.
(b) Screw down the fastening bolts of the back plate to
prescribed torque.
Tighten torque: 82N
m

8.

Flywheel
(a) Coat the flywheel bolts with engine oil.
(b) Screw down the flywheel bolts to prescribed torque by
angle-screw home method in two steps.
Flywheel bolts torque
N
m
First step(pre-tighten torque)
59

9.
4D28

Second step(fianal torque)

60-90

Cylinder cover assembly

(1) cylinder cover gasket
The cylinder cover gasket is determined according to the
projection of the cylinder top against the engine top surface.
Three different thickness gasket have been provided to
improve the engine performance.
Select a suitable gasket in the three groups according to the
following procedures.
Remove carbon deposit on top of the cylinder and the engine.
Surface installed with gasket shall be cleaned also.

EM-18

Mechanical system-Camshaft and transverse member

(2) Measure the piston top projection
(a) Measure the piston projection with a micrometer.
(b) Refer to the illustration for measuring position of the piston
top projection.
All the measuring positions shall be as adjacent to the cylinder
bush as possible.
(c) Measure the points
 ! and derive two differences

and
-
for each cylinder.
(d) Obtain the maximum from four cylinders.
(e) The gasket group shall be selected according to the next table
with above mentioned maximum.

4D28 cylinder cover gasket thickness

Gasket No.

(A)
(B)
(C)

mm

Piston top
projection

Gasket thickness
(just for reference)

0.758-0.813
0.813-0.859
0.859-0.914

1.50
1.55
1.60

Attention: Difference between the maximum and minimum

of piston top projection shall not exceed 1.0mm.
(3) cylinder cover
(a) Mount the cylinder cover fixing pin onto the engine body.
(b) The top mark shall be toward upside when mounting the
cylinder cover gasket.
(c) Clean the bottom surface of the cylinder cover and top surface
of the engine body.
(d) Smear machine oil on the bolt threads and mating surface of
the cylinder cover.
(e) Screw down the support bolts of the cylinder cover bolts by
three steps to prescribed torque according to the procedure
shown in the diagram.
Cylinder cover bolts torque
First step
49

Second step
60-75

N
m
Third step
60-75

(4)

Push rod
Smear the push rod with engine oil and insert it into the
cylinder cover.
(5) Rockshaft assembly
(a) Loose all the adjusting screws.
(b) Assemble the rockshaft with its large engine oil hole (4)
face front of the engine.

(c) Screw down the support bolts of the rockshaft to prescribed

torque according to the procedure shown in the diagram.
Tighten torque: 54N
m
(d) Adjust the air valve clearance.

EM-19

Mechanical system- Crankshaft

Crankshaft

Disassembly procedure
1. cylinder cover assembly
2. oil bottom casing assembly
3. timing gear
4. injection pump assembly
5. timing gear chamber
6. engine oil pump assembly
7. piston and connecting rod assembly
8. flywheel
9. back plate of the machine body
10.back oil seal of the crankshaft
11.main bearing cover.
12.crankshaft

Reassembly procedure
Assemble according to the reverse
procedure of disassembly.

Disassembly
1.
2.

Cylinder cover assembly

Oil bottom casing assembly

3.

Timing gear

4.
5.

Injection pump assembly

Timing gear chamber

6.
7.

Engine oil pump assembly

Piston and connecting rod assembly

8.

Flywheel

9.

Back plate of the machine body

10. Back oil seal of the crankshaft

Push the oil seal deeply, mount special tool as shown in the
diagram to dismount the oil seal.
Rear oil seal detacher: 5-8840-2360-0
Attention:
Take care not to damage the back plate and crankshaft
seal surfaces when dismounting the oil seal.
11. Main bearing cover.
12. Crankshaft

EM-20

Mechanical system- Crankshaft

Inspection and maintenance

Parts must be adjusted, repaired or replaced when excess wear or damage
is found in examination.
1. Crankshaft thrust clearance
Mount dial gauge as shown in the diagram and measure the crankshaft
thrust clearance.
The thrust bearings must be replaced as a whole if thrust clearance exceeds
the prescribed limit value.
crankshaft thrust clearance
mm
Limit
0.30

Standard
0.10

2. Camshaft main bearing clearance

(a) Remove main bearing cover gradually as shown in the diagram
Place the main bearing cover according to the cylinder serial number.
(b) Remove the crankshaft
Remove the main bearing
(c) Clean the surfaces of top/bottom bearings and crankshaft main journal.
(d) Examine if the main bearing is damaged or excessively worn.
The main bearings must be replaced as a group when excess wear or
damage is found in examination.
(e) Assemble the top bearing and thrust washer to their original positions.
Mount the crankshaft carefully.
(f) Mount the bottom bearing onto the main bearing cover of original position.
(g) Place a plastic line gap gauge onto the crankshaft main journal.
(h) Mount the main bearing cover.
Smear machine oil on the bolt threads and mating surface of the main
bearing cover, screw down the main bearing cover bolts to prescribed
torque.
Tighten torque: 167N
m
Attention:
Crankshaft rotation is not permitted.
(i) Remove the main bearing cover.
(j) Measure the width of the plastic line gap gauge and determine oil film gap.
Main bearings and/or crankshaft must be replaced as a whole if oil film
clearance exceeds the prescribed limit value.
(k) Erase the plastic line gap gauge from the main bearing and crankshaft.
(l) Remove the crankshaft and main bearing
Oil film clearance
mm
Standard
0.035-0.080

3.

Limit
0.11

Radial jump of the camshaft

(a) Place the crankshaft carefully on the V-block
Turn the crankshaft slowly and measure its radial jumping.
The crankshaft must be replaced if the radial jump of crankshaft
exceeds the prescribed limit value.
Radial jumping
Standard
<=0.05

mm
Limit
0.08

EM-21

Mechanical system- Crankshaft

(b)

Measure the diameter and non-uniform wear of the

crankshaft main journal and the crankpin.
The crankshaft must be replaced if non-uniform wear of
the crankshaft exceeds the prescribed limit value.
mm

Main journal diameter

Connecting rod journal diameter
non-uniform wear

4.

Standard
69.917-69.932
52.915-52.930
0.05 or leass

Limit
69.91
52.90
0.08

Crankshaft examination
(a) Examine if there is any excessive wear or damage of the
crankshaft main journal and the crankpin surfaces.
(b) Examine if there is any excessive wear or damage on the
oil seal mating surface.
(c) Examine if there is any blockage in the oil hole.

5.

The surfaces being examined

shall be fully horizontal to
prevent solution flow.
The sliding surface of
crankshaft main journal
or crankpin.

Crankshaft soft nitriding examination

(a) Clean the crankshaft thoroughly with a kind of organic
Solution flowing to oil
substance.
hole and its periphery
area is not permitted.
There should be no oil trace on the surfaces being
examined.
(b) Prepare ammonium chloride copper solution of 5%-10%
About 10mm
concentration (dissolved in distilled water)
(c) Smear the solution onto the surfaces being examined with
injector.
The surfaces being examined shall be fully horizontal to
prevent solution flow.
Attention: Solution flowing to oil hole and its periphery area is not permitted.
(d) Test
(1) Wait for 30 to 40 minutes.
If the surface color does not change for 30 to 40 minutes, then the crankshaft can be
applied.
The crankshaft must be replaced if the surface being tested changes color (to cooper
color).
(2) Wash the crankshaft surface with steam immediately after the test has been completed.
Attention:
Ammonium chloride copper solution is highly corrosive.
So, it is absolutely necessary to wash surface being tested immediately after the
test has been completed.
6. Camshaft bearing selection
Please refer to the following selection table when assembling

No.3
No.1

No.2

No.4

No.5

a new camshaft bearing or replacing the old bearing.

Pay attention to diameter dimension marks on the engine body
journal hole
and the camshaft main journal
when selecting and installing new camshaft bearings.

EM-22

Mechanical system- Crankshaft

Attention:
Pay attention to distinguish top bearing (engine body
side) form bottom bearing (main bearing cover side) of
the main journal even though there are oil groove and
hole on the main journal top bearing (engine body side)
and not on the main journal bottom bearing (main bearing
cover side).

Diameter of main bear (mm)

Dimension
mark

Inside diameter

73.987-74.000

73.975-73.987

Diameter of main journal of

crankshaft (mm)
Dimension
mark

Inside diameter

1 or

2 or

3 or

1 or

2 or

3 or

69.927-69.942
69.922-69.927
69.917-69.922
69.927-69.942
69.922-69.927
69.917-69.922

Dimension mark
of crankshaft
bearing
Black
Blue
Green
Black

Oil film
clearance (mm)
0.035-0.061
0.032-0.058
0.063-0.087
0.031-0.056
0.036-0.048
0.033-0.058

Reassembly
1. Crankshaft
(a)

Mount the main bearing onto the engine body and main
bearing cover.
Ensure their proper positions.

(b) Coat the top/bottom main bearing surfaces with engine oil.
(c) Mount the crankshaft carefully.
(d)

Coat the thrust washer with engine oil.

(e)

Mount the thrust washer into the washer groove of the

third main journal.Oil groove in the thrust washer must
face the crankshaft.

2. Main bearing cover.

(a)

Coat the fifth bearing cover
with recommended liquid

sealant and the similar as shown in the diagram.

(b) Mount the arc gasket
into the groove in the fifth main
bearing cover.

Mechanical system- Crankshaft

EM-23

(c) Coat the fifth bearing cover
with recommended liquid

sealant and the similar as shown in the diagram.
Attention:
Ensure there is not any oil dust on the bearing cover
mating surface before coating liquid sealant. Cylinder
screw thread hole and bearing blockage by liquid sealant

is not permitted.

(d) Mount main bearing cover, the arrow mark on top of the
main bearing cover shall face front of the engine.

(e) Smear new machine oil on the mating surface of bolts and
threads of main bearing cover.

(f) Screw down the main bearing cover bolts gradually for
several times to prescribed torque according to the order

number shown in the diagram, each for a little.

Tighten torque: 167N
m

Attention:

Turn the crankshaft by hand to examine if the crankshaft

rotates freely.
3.
12.5
0.3

4.
5.

Back oil seal of the crankshaft

(a) Mount the crankshaft rear oil seal onto the engine body
with an oil seal erector.
rear oil seal erecter: 5-8840-2359-0
Attention:
Clean rust and scrap of oil seal pressing part.
Pay attention to oil seal press in direction.
(b) Fix the connector of the special tool to the end of the
crankshaft with two bolts.
(c) Mount the oil seal onto outer periphery of the joint.
(d) Insert the bush into the joint, screw down the bolts

M12

1.75
L=70
until the joint end surface contacts
with the bush.
(e) Remove the joint and bush.
(f) Examine the installation dimension of oil seal after it has
been installed.
Standard value: (12.2-12.8)mm.
Back plate of the machine body
Flywheel
(see page EM-17)

EM-24

Mechanical system- Crankshaft

6.

Piston and connecting rod assembly

(a) Mount the connecting rod bearing onto the connecting
rod body and its bearing cover.
(b) Smear the cylinder bush hole, connecting rod bearing and
the crankpin with new engine oil.
(c) Examine if the opening position of piston ring is correct.

(d) Mount the piston and connecting rod assembly into the
cylinder with a piston ring compressor.
Place the piston and connecting rod in position, the front
marks on top of the piston and connecting rod must face
the direction of engine.

7.
8.

Engine oil pump assembly

(See page EM-17)
Timing gear chamber
(a) Mount the timing gear chamber onto the engine body.
Attention:
Take care not to twist front oil seal.
(b) Screw down fixing bolts of the timing gear chamber and
its gasket to prescribed torque.
Tighten torque: 19N
m
(c) Cut off the projection part on the gasket of joint surface.

9. Injection pump assembly

(a) Install examination whole covers on the camshaft gear
side in gear chamber, timing gear side of oil injection
pump.
(b) Turn the crankshaft clockwise and examine if the TDC
scratch in the crankshaft pulley aligns with the pointer.
Put the piston in the first cylinder to compression travel
top dead point.
(c) Examine if the mark O scratch on the camshaft timing
gear aligns with the pointer in the inspection hole through
inspection hole on the camshaft timing gear side.
(d) On above mentioned conditions, align the mark O of oil
injection pump with the inspection hole pointer and
mount oil injection pump assembly.
(e)
camshaft gear

injection pump gear

Mount the fastening bolts of the oil injection pump

assembly and screw down to prescribed torque.

Tighten torque: 20N
m

Mechanical system- Crankshaft

EM-25

10. Timing gear

(1) Crankshaft timing gear
Mount the camshaft timing gear
with camshaft erector
.
The mark
X-X
on the camshaft timing gear must face

outside.
Camshaft gear erecter: 9-8522-0020-0

(2) camshaft timing gear

(a) Install the camshaft thrust plate onto the engine body and
screw down the camshaft thrust plate to prescribed torque.
Tighten torque: 18N
m
(b) Mount the camshaft timing gear onto the camshaft.
The mark
Y-Y
on the camshaft timing gear must face
outside.
(c) Screw down the fastening bolts of the camshaft timing
gear to prescribed torque.
Tighten torque: 85N
m
(3) Idle gear
A

(a) Smear the idle gear and its shaft with machine oil.
Oil hole of idle gear shaft must face upward.
(b) Positioning mark
X
and
Y
on the idle gear
A

shall be installed facing front of the engine.
Positioning mark
X
of the idle gear shall align the
positioning mark
X-X
of the camshaft timing gear
.
Positioning mark
Y
of the idle gear shall align the
positioning mark
Y-Y
of the camshaft timing gear
.
(d) Mount the thrust ring onto the engine body.
The oil hole of thrust ring must face upward and the
chamfer must face outside.
(e) Screw down the fastening bolts of the idle gear
A
to
prescribed torque.
Tighten torque: 19N
m

(c)

(4) Idle gear
B
and its shaft

(a) Smear the idle gear and its shaft with machine oil.
(b) Positioning mark
Z
of the idle gear
B

shall
align with the positioning mark
Z-Z
of the idle gear

A

.
(c) Screw down the fastening bolts of the idle gear
B
to
prescribed torque.
Tighten torque: 76N
m

EM-26

Mechanical system- Crankshaft

(5)

Injection pump

(a)

Mount the O-ring
onto oil injection pump flange
.

(b) Mount the oil injection pump onto the timing gear chamber.
Align the positioning mark
V-V
of the idle gear
B


with the mark
V
of the o il injection pump timing
gear
A

.

(c)

Screw down six oil injection pump bracket bolts

temporarily.
Screw down oil injection pump bracket bolts after screwing down oil injection pump rear bracket bolts.

(d)

Mount oil injection rear bracket
and its bolts
onto

the engine body.
Mount the rear bracket bolts
onto the oil injection

pump bracket
.
screw down the rear bracket bolts
and
to prescribed
torque.

Tighten torque: 19N
m

(6) Timing gear engine oil pipe

(a) Mount the oil pipe onto the timing gear chamber and the

idle gear
A

.
(b)

screw down the eye bolts
and fixing bolts
of oil pipe
to prescribed torque.
Screw down torque of oil pipe eye bolts is: 13N
m
Screw down torque of oil pipe fixing bolts is: 19N
m

(7) Timing gear chamber cover

(a) Align the gear chamber cover with timing gear chamber
positioning pin and then mount the gear chamber cover.
(b) Screw down the fastening bolts of the gear chamber cover
to prescribed torque.
Tighten torque: 19N
m

Mechanical system- Crankshaft

EM-27

(8) Crankshaft vibration absorber pulley

Screw down the fastening bolts of the crankshaft vibration absorber pulley to prescribed torque.
Tighten torque: 206N
m
Attention:
Crankshaft rotation shall be prevented when
screwing down the fastening bolts of the crankshaft
vibration absorber pulley.

power steering pump

driving belts

(9) AC electric generator and power steering pump driving

belts
(a)

Mount the driving belt of AC generator and power

steering pump, adjust their tensity.

(b) Press the middle of the driving belt with 98N force.
Driving belt deflection: (8-12) mm.
the driving belt of AC
generator

(10) Cooling fan assembly

Mount the fan pulley and cooling fan assembly onto the
water pump and screw down the locknuts to prescribed
torque.
Tighten torque: 8N
m

(11) Fan air guide shield

(a) Mount the fan air guide shield and water overflow tank
hose.
(b) Charging coolant
(c) Start the engine and check if there is any coolant leakage.

11. Oil bottom casing assembly

(See page EM-17)
12. Cylinder cover assembly
(See page EM-17)

EM-28

Mechanical system-Piston and the connecting rod assembly

Piston and the connecting rod assembly

Disassembly procedure
1. cylinder cover assembly
2. oil bottom casing assembly
3. engine oil pump assembly
4. connecting rod bearing cover
5. piston and connecting rod assembly
6. piston ring
7. retaining ring of the piston pin
8. piston pin
9. piston
10. connecting rod
Reassembly procedure
Assemble according to the reverse
procedure of disassembly.

Disassembly
1.

Cylinder cover assembly

2.
3.

Oil bottom casing assembly

Engine oil pump assembly

4.

Connecting rod bearing cover

5.

Piston and connecting rod assembly

Scrape the carbon deposit on the cylinder wall with scraper
before removal of piston and the connecting rod assembly.

6.

Piston ring
Dismount the piston ring with a piston ring extender.
Place the piston ring according to the cylinder serial number.

7.

Retaining ring of the piston pin

Remove the retaining ring of the piston pin with a nipper plier.

8.

Piston pin
Attention:
Place the parts dismounted from each cylinder by order.
All of the parts must be reassembled to their original
positions when reassembly.

9. Piston
10. Connecting rod

EM-29

Mechanical system-Piston and the connecting rod assembly

Inspection and maintenance

1.

Piston
(a) Remove carbon deposit on top of the piston and on the piston
ring grooves carefully.
Attention:

Do not clean the piston with a metal brush, or the piston
may be damaged.

Visually examine if there is any crack, scar or other
excessive wear on each cylinder.
The piston must be replaced if any above mentioned
occurs.
(b) Measure piston outer diameter with spiral micrometer on
piston group position. Piston group position: 74mm.
Piston outer diameter
mm
Dimension mark

Standard value

92.985-92.994

92.995-93.004

93.005-93.014

93.015-93.024

TQ

(c) Measure the inner diameter of the cylinder casing hole.

Inner diameter of the cylinder casing hole

mm

Dimension mark

Standard value

93.021-93.030

93.031-93.040

93.041-93.050

93.051-93.060

Piston clearance: (0.025-0.045)mm

2.

Piston ring
(1) Opening clearance of the piston ring
Mount the piston ring into the cylinder casing.
Measure the opening clearance with a feeler gauge.
Opening clearance of the piston ring
mm
Standard value
Air ring

First ring

0.20-0.40

Second ring

0.20-0.40

Oil ring

Limit value
0.150

0.10-0.30

(2) Axial direction gap between the piston ring and piston ring groove
Measure the axial direction gap between the piston ring and
piston ring groove with a feeler gauge.
The piston must be replaced if the gap exceeds the prescribed limit value.
Axial direction gap between the piston ring and piston ring
groove
mm

Air ring

First ring
Second ring
Oil ring

Standard value
0.090-0.125
0.050-0.075
0.03-0.07

Limit value
0.150

EM-30

Mechanical system-Piston and the connecting rod assembly

3.

Piston pin
Examine the piston pin visually to find if there is any crack, scar or
other damage on it, replace the piston pin when necessary.
(a) Measure the outer diameter of the piston pin on three different
positions and along two different directions with a spiral micrometer.
The piston pin must be replaced if the measurement value exceeds
the prescribed limit value.
Outer diameter of the piston pin
mm
Limit
30.970

Standard
30.995-31.000

(b)

Measure the inner diameter of the small end hole of the

connecting rod.
If the gap between the small end hole of the connecting rod and
the piston pin do not comply with requirement, the connecting
rod or the bush and the piston pin must be replaced.
Gap between the small end hole of the connecting rod and the
piston pin
mm
Limit
0.05

Standard
0.008

(c) Insert the piston pin into its seat hole and turn it.
If the piston pin turns freely with no gap, then the gap is normal.
Measure the gap if there is any gap or roughness.
The piston or piston pin must be replaced if the gap exceeds the
prescribed limit value.
Axial direction gap between the piston pin and piston pin seat
hole==

Limit
0.04

Standard
0.002-0.004

4.

Bush
Disassembly: with suitable bar and table press or hammer.
Assembly: with suitable bar and table press.
Attention:
The bush shall align with the oil hole of the connecting
rod small end.
Grind the bush hole with pin hole grinding miller after new
bush installed.

5.

Connecting rod
(1) Reducer hole axial line error of the connecting rod.
Examine the reducer hole axial line error of the connecting rod with connecting rod calibrator.
The connecting rod must be replaced if the degree of
bending or distortion exceeds the prescribed limit value.
The degree of bending
The degree of distortion

Standard

Limit

0.08 or less

0.20
0.15

0.05 or less

EM-31

Mechanical system-Piston and the connecting rod assembly

(2) Axial gap of the connecting rod

Measure the thrust clearance of the large end of connecting rod
with feeler gauge.
The connecting rod must be replaced if the measurement value
exceeds the prescribed limit value.
Axial gap of the connecting rod
mm
Standard
0.230

Limit
0.350

(3)

Oil clearance between the connecting rod bearing and the

crank pin
(a) Dismount nuts of the connecting rod bearing cover; remove the
connecting rod bearing cover.
Place the connecting rod bearing cover according to the cylinder serial number.
(b) Clean the surface of connecting rod bearing and crank pin.
(c) Examine carefully if there is any damage of the connecting rod
bearing.
All of the bearings shall be replaced as a whole even if only a
bearing is found damaged or severe wear.
(d) Reassemble the connecting rod bearings to their original
positions.
(e) Place a plastic line gap gauge onto the crank pin.
(f) Reassemble the connecting rod bearing cover to their original
position.
(g) Screw down the connecting rod cover nuts to prescribed torque
by angle-screw home method in two steps
Torque of the connecting rod cover nuts
N
m
Standard
45

Limit
60-90

Attention:
Crankshaft rotation is not permitted when screwing down the
connecting rod cover nuts.
(h) Dismount the connecting rod bearing cover.
(i) Measure the width of the plastic line gap gauge and determine
oil film gap.
The connecting rod bearings must be replaced as a whole if the
gap exceeds the prescribed limit value.
(j) Erase the plastic line gap gauge from the crank pin.
Oil clearance between the connecting rod bearing and the crank
pin
mm
Standard
0.029-0.066

Limit
0.100

Reassembly
front mark

ISUZU mark

1. Connecting rod
2. Piston
(a) Mount the piston onto the connecting rod. Front mark on top of
the piston shall be at the same side with the casting mark

ISUZU
on the connecting rod.
Attention:
Do not change the mating assembly of the piston and its pin when
replacing the piston and the connecting rod mating assembly.

EM-32

Mechanical system-Piston and the connecting rod assembly

3.

Piston pin
(a) Smear the piston pin and its seat hole with machine oil.
Push the piston pin into the hole of piston pin seat hole.
(b) Weight the assembly of each piston and connecting rod.
Weight difference of difference cylinder and same assembly shall be limited to prescribed range when selecting the assembly of piston and connecting rod.

4.

Prescribed value: Less than 3g.

Retaining ring of the piston pin

5.

Piston ring
(a) Mount the piston ring with a piston ring extender.
The mark
N
shall be toward upside when mounting the
caustic ring.
The position of the identification mark is shown in the diagram.

N mark
air ring

(b) The piston ring shall be assembled as following procedures.

Oil ring

Oil ring with spiral expansion ring.

The second air ring

The first air ring

(c) Smear the surfaces of all the piston rings with machine oil
after assembly has been completed, examine if the piston
ring rotates freely.
6.

Piston and connecting rod assembly

(a) Smear the surfaces of the cylinder casing hole, connecting rod bearing, crank pin, piston ring and piston
Examine if the opening position of piston ring is correct.

(b) Mount the piston and connecting rod assembly into each
cylinder with a piston ring compressor.
The front mark on top of the cylinder must be forward.

EM-33

Mechanical system-Piston and the connecting rod assembly

7.

The connecting rod bearing cover.

(a) Align the stamped marks of the connecting rod and the
connecting rod bearing cover.
(b) Smear machine oil on the bolt threads and mating surface
of the connecting rod bearing cover.
(c) Screw down the connecting rod cover nuts to prescribed
torque by angle-screw home method in two steps.
Torque of the connecting rod cover nuts
First step(pre-tighten torque)
45

(d)

8.

Examine if the crankshaft rotates freely after screwing

down the connecting rod cover nuts.

Engine oil pump assembly

(See page EN-17)

9.

N
m

Second step(final torque)

60-90

Oil bottom casing assembly

(See page EN-17)

10. Cylinder cover assembly

(See page EN-17)

EM-34

Mechanical systemJEngine oil pump assembly

Engine oil pump assembly

Disassembly procedure
1. flywheel
2. back plate of the machine body
3. oil bottom casing assembly
4. engine oil pump assembly
5. oil pipe
6. strainer
7. pump cover
8. driven gear and bush
9. driving gear
10.driven shaft
11.pinion pin
12.pinion
13.driving shaft
14.engine oil pump body

Reassembly procedure
Reassemble according to the reverse
procedure of disassembly.

Disassembly
1. Flywheel
2. Back plate of the machine body
3. Oil bottom casing assembly
4. Engine oil pump assembly
5. Oil pipe
6. Strainer
7. Pump cover
8. Driven gear and bush
9. Driving gear
10. Driven shaft
11. Pinion pin
(a) File the riveting end of the pinion retention pin to flat.
(b) Knock the pinion pin out with a hammer and rod.
(c) Dismount the pinion.
12. Pinion
13. Driving shaft
14. Machine oil pump body

EM-35

Mechanical system-Engine oil pump assembly

Inspection and maintenance

Parts must be adjusted, repaired or replaced when excess wear
or damage is found in examination.
Casing and gears
The machine oil pump assembly must be replaced if following
conditions are found in examination.
(a) Excess wear or damage of driven gear shaft bush.
(b) Excess wear or damage of gear teeth.
Gap between gear top tooth and the casing inner surface
(a) Measure the gap between gear top tooth and the casing
inner surface with a feeler gauge.
(b) Either the gear or the casing must be replaced if the gap
between gear top tooth and the casing inner surface
exceeds limitation.
Gap between gear top tooth and the casing inner surface mm
Standard
0.14

Limit
0.20

Gap between the pump cover and the gear

(a) Measure the gap between the pump cover and the gear
with a feeler gauge.
(b) The casing must be replaced if the gap between the pump
cover and the gear exceeds the prescribed limit value.
Gap between the pump cover and the gear
Standard
0.06

mm

Limit
0.15

Gap between the driving shaft and the machine oil pump body
(a) Measure the outer diameter of driving shaft with a spiral
micrometer.
(b) Measure the inner diameter of the pump body with an
inner diameter micrometer.
(c) The machine oil pump assembly must be replaced if the
gap between the driving shaft and the machine oil pump
exceeds the prescribed limit value.
Gap between the driving shaft and the machine oil pump body mm
Standard
0.04

Limit
0.20

Gap between the driven shaft and the bush

(a) Measure the outer diameter of driven shaft with a spiral
micrometer.
(b) Measure the inner diameter of the bush with an inner
diameter micrometer.
(c) The bush must be replaced if the gap between the driven
shaft and the bush exceeds the prescribed limit value.
Gap between the driven shaft and the bush
mm
Standard
0.05

Limit
0.15

EM-36

Mechanical system-Engine oil pump assembly

Reassembly
1. Engine oil pump body
2. Main shaft
3. Pinion
4. Pinion pin
(a) Mount the new transmission shaft onto the machine oil
pump body.
(b) Mount the pinion onto the driving shaft.
(c)

Drill a hole of 5mm diameter to let the pinion and

transmission shaft through.

(d) Insert the pinion pin into the hole.Rivet the small pin
5. Driven shaft
6. Driving gear
7. Driven gear and bush
8. Pump cover
9. Strainer assembly
Mount the strainer assembly and screw down its fastening
bolts to prescribed torque.
Tighten torque: 16N
.
10. Oil pipe
11. Engine oil pump assembly
(See page EN-17)
12. Oil bottom casing assembly
(See page EN-17)
13. Back plate of the machine body
(See page EN-17)
14. Flywheel
(See page EN-17)

EM-37

Mechanical system- Engine body

Engine body

Disassembly procedure
1. cylinder cover assembly
2. pil bottom casing assembly
3. timing gear
4. oil injection pump assembly
5. timing gear chamber
6. engine oil pump assembly
7. piston and connecting rod assembly
8. flywheel
9. back plate of the machine body
10. back oil seal of the crankshaft
12. crankshaft
13. transverse member
14. camshaft
15. engine body

Reassembly procedure
Reassemble according to the reverse
procedure of disassembly.

Disassembly
1.

Cylinder cover assembly

2.
3.

Oil bottom casing assembly

Timing gear

4.

Injection pump assembly

5.
6.

Timing gear chamber

Engine oil pump assembly

7.
8.

Piston and connecting rod assembly

Flywheel

9.

Back plate of the machine body

10. Back oil seal of the crankshaft

EM-38

Mechanical system- Engine body

11. Main bearing cover.
12. Crankshaft
13. Transverse member
14. Camshaft
15. Engine body

Inspection and maintenance

Parts must be adjusted, repaired or replaced when excess wear
or damage is found in examination.
(a) Remove the gasket and any attachment on the surfaces of
the machine body.
Notes:
Take care not let any matter drop into the machine body.
Take care not to score the machine body surface.
(b) Remove the gasket on the contact surface of the oil pump
assembly ,rear oil seal retaining ring and oil bottom casing.
(c)

Clean the surface of machine body.

Cylinder bush projection quantity examination

(a) Put the straight ruler at the top edge of cylinder bush to be
measured.
(b) Measure projection quantity of each cylinder bush.
Cylinder bush projection quantities difference between
two adjacent cylinders shall not exceed 0.03mm.
Standard value: (0.0-0.1)mm.

Flatness
(a) Dismount the fixing pin of machine body.
(b) Mount the cylinder bush detacher onto the cylinder bush.
(c)

Examine if the base frame on the detacher shaft moves

around the edge of the cylinder bush bottom.

(d) Turn the handwheel of detacher shaft anti-clockwise slowly

to pull the cylinder bush out.
Cylinder bush detacher: 5-8840-2039-0
Attention:
Take care not to damage the surface of the cylinder when
dismounting the cylinder bush.
(e) Measure four edges and two diagonal lines of the machine
body surface with straight ruler and feeler gauge.The
machine body must be replaced if the measurement value
exceeds the prescribed limit value.

EM-39

Mechanical system- Engine body

Measurement of the Inner diameter of cylinder

casing hole
Measure the cylinder bush hole diameter of measurement point

along thrust direction
-
and crankshaft axial direction
-
.
Height of measurement point
:20mm
The cylinder bush must be replaced if the measurement value
exceeds the prescribed limit value.
Attention:
Do not regrind or grind inner surface of dry cylinder bush
because it is chroming.
The cylinder bush must be replaced if there is any scratch or

burn in the cylinder bush inner surface.

Selection of cylinder bushes group

Measure the inner diameter of cylinder hole, select suitable cylinder
bushes group.
Standard fitting interference: (0.001-0.019)mm
Cooling efficiency for the engine will be affected if fitting interference of the cylinder bush is too small.
Difficulty will arises when mounting the cylinder bush into the
cylinder hole if fitting interference of the cylinder bush is too large.
Attention:
There are two methods for cylinder bush selection.
Method I
Mark have been stamped on the engine body surface in manufacturing to indicate correct cylinder bush size.
Cylinder bushes groups (1, 2, 3, 4 and etc.) are printed with
permanence ink.
Select proper cylinder bush according to the following method if
there is any question of the cylinder bush marks.
Method II

Measurement of the engine body inner hole

(a) Measure the inner diameters of section I-I, II-II, III-III and IVIV at measuring point
.
Height of measurement point
:98mm
(b) Calculate mean value of four measured dimensions to determine suitable cylinder bushes group.
(c) Refer to the following table on the basis of the mean value,
select suitable cylinder bushes group.
4D28
Classified cylinder
bush
1
2
3
4

mm
Average diameter of
inner hole of engine body
95.001-95.010
95.011-95.020
95.021-95.030
95.031-95.040

Outside diam eter of

cylinder bush
95.011-95.020
95.021-95.030
95.031-95.040
95.041-95.050

EM-40

Mechanical system- Engine body

Installation of the cylinder bush

(a)

Clean thoroughly surfaces of the cylinder bush and

cylinder hole with fresh kerosene or diesel oil.

(b) Blow surfaces of the cylinder bush and cylinder hole to

dry with compressed air.

(c) Mount the cylinder bush with special tool.
Cylinder bush erector: 5-8840-2040-0
Attention:
Removal all foreign bodies from the cylinder bush and
cylinder hole carefully before mounting the cylinder bush.

(d) Press the cylinder bush
into the cylinder hole
from
top of the engine body.

(e)

Mount the cylinder bush erector
on top of the cylinder

bush.

(f)

The engine body position shall ensure the erector centre

line directly under the table press axle centre
.

Attention:
Examine to ensure that the engine body is perpendicular
to the table press and there is no shake.
(g) Exert allocation force of 4,900N on the cylinder bush with
a table press.
(h) Exert force of 24,500N to make the cylinder bush fully in
position.
(i)

After the cylinder bush being mounted, measure its projection quantity.
Refer to
Cylinder bush projection quantity examination

in this chapter.

(j) Measure the diameter of cylinder bush, select suitable cylinder bushes group.

Reassembly
1. Engine body
2. Camshaft
(a) Apply machine oil into the transverse member surface
and its mounting hole.
(b)

Mount the transverse member according to the position

in disassembly (if the transverse member will be reused).

(c) Smear the camshaft and its bearings with machine oil.
(d) Mount the camshaft onto the engine body.
Take care not to damage the camshaft bearings.
3. Transverse member
4. Crankshaft
(See page EN-22)
5. Main bearing cover.
(See page EN-22)
6. Back oil seal of the crankshaft
(See page EN-23)
7. Back plate of the machine body
8. Flywheel

(See page EN-17)

Mechanical system- Engine body

9.

EM-41

Piston and connecting rod assembly

(a) Smear the piston pin and its seat hole with machine oil.
Push the piston pin into the hole of piston pin seat hole.
(b) Weight the assembly of each piston and connecting rod.
Weight difference of difference cylinder and same assembly shall be limited to prescribed range when selecting the assembly of piston and connecting rod.
Prescribed value: Less than 3g.
(c) Clamp the connecting rod with a jaw.
Take care not to damage the connecting rod.
(d) Mount the piston pin retaining ring into its groove with
nipper pliers.
Attention:
Do not change the mating assembly of the piston and its
pin when replacing the piston and the connecting rod
mating assembly.

(e) Mount the cylinder onto the connecting rod.

Front mark
on top of the piston and the casting mark

ISUZU

on the connecting rod shall face the same

direction.

(f) Smear the piston pin and its seat hole with machine oil
Press the piston pin into the piston with fingers until it
contacts with the piston pin retaining ring.

(g) Mount the piston pin retaining ring into its groove with
fingers.
Examine if the connecting rotates freely on the piston pin.

EM-42

Mechanical system- Engine body

(h)

Coat the piston ring surface with engine oil.

Mount three piston rings with a piston ring replacer.

Piston ring replacer: 5-8840-9018-0

The piston ring shall be assembled as following

procedures.

Oil ring

The second air ring

The first air ring

Attention:

The marked face shall be toward upside when mounting
the caustic ring.The identification mark is shown in the
diagram.

Mount the spiral expansion ring into the grooves of oil
ring, ensure there is no clearance around any side of the
expansion ring before mounting the oil ring.
N mark
air ring

(i)
the second ring

Place the opening position of piston ring properly as

shown in the diagram.

expansion ring

Examine if the piston ring rotates freely on the piston

ring groove.
front mark
oil ring

the first ring

(j) Removal the oil stain and foreign bodies on the connecting
rod bearing surface.
(k) Coat the top/bottom bearings of the connecting rod with
engine oil, mount them into the connecting rod bearing
seats.

(l)

Coat the cylinder wall with engine oil.

Place the piston in position, the front mark on top of the
piston must face the direction of engine.
Compress the piston ring with a piston ring compressor.

Piston ring compressor: 5-8840-9018-0
J-8037

(m) Push the piston into the cylinder with hammer shaft until the
top bearing of connecting rod contacts with the crank pin.
Turn the crank pin at the same time until it locates at the
bottom dead point.

EM-43

Mechanical system- Engine body

(n) Place the connecting rod bearing cover in position. The

front mark on top of the piston must face the direction of
engine.
Align the cylinder serial number on the connecting rod
bearing cover with that on the connecting rod.

front mark

(o) Smear machine oil on the bolt threads and mating surface
of each connecting rod bearing cover.
(p)

Screw down the connecting rod bearing cover nuts to

prescribed torque by angle-screw home method in two

steps.
Torque of the connecting rod cover nuts
First step(pre-tighten torque)
45

N
m

Second step(final torque)

6 0 - 9 0

Attention:
Turn the crankshaft by hand to examine if the crankshaft
rotates freely.
10. Engine oil pump assembly
(see page EN-17)
11. Timing gear chamber
12. Injection pump assembly
13. Timing gear
(see page EN-25)
14. Oil bottom casing assembly
15. Cylinder cover assembly
(see page EN-17)

EN-1

4D28 Engines
Page

General description .....................................................

Engine assembly .........................................................
Engine bracket ............................................................
Intake manifold ............................................................
Exhaust manifold .........................................................
Cylinder cover cap ......................................................
Rockshaft assembly ....................................................
Valve oil seal and valve spring ....................................
Cylinder cover assembly and sealing washer .............
Timing gear .................................................................
Oil filter assembly ........................................................

EN-2
EN-3
EN-7
EN-9
EN-11
EN-13
EN-14
EN-16
EN-18
EN-23
EN-28

Flywheel and transmission primary shaft front-bearing.... EN-30

Oil pump assembly...................................................... EN-32
Oil pan assembly ......................................................... EN-34
Camshaft and tappet stem .......................................... EN-36
Piston and connecting rod assembly .......................... EN-40
Crankshaft front-seal ................................................... EN-45
Crankshaft rear-seal .................................................... EN-47
Crankshaft front-seal ................................................... EN-49
Housing ....................................................................... EN-53

EN

EN-2

GW4D28 Diesel-engines-General description

General description

4D28

The GW4D28 diesel engine employs shaped combustion chamber. This kind of design results in good fuel
economy in a broad stroke.
The cylinder cover sealing washer is piled with thin sheet steels.
The cylinder cover sealing washer can be divided into three dimensions according to the bulging that the top of the
piston protrudes the block, and then this can reduce the deviation range of the compression ratio
Tight the cylinder cover fixing bolts, connecting rod fixing bolts and flywheel fixing bolts with the angle-tight
method
The steel chome plated dry liner has higher durability
The automatic thermal compensation piston is sustained by cast steel to abate noises caused by heat expansion and
cooling down.
The soft nitriding crankshaft has a long life.The crankshaft cant be reground because of the Tenifer process
The crankshaft main bearing and rod bearing are both made of aluminum alloy. This kind of bearing is vulnerable
to being damaged by impurities (such as flitter).So it is very important to keep oil orifice and other related surfaces clean
and to discharge impurities.
The Tenifer process (nitrogen treatment) of the crankshaft increases its strength and dispense with regrinding
crankpin and maneton and such work.
The oil injection equipment cooling the piston is set in the oil circuit to inject oil to the piston from the oil passage
of the housing through the check valve.
Take care not to damage the oil nozzle when disassembling and assembling piston and rod assembly.
The GW4D28 diesel engine is a direct injection diesel engine. The injector has four orifices and then this may obtain
the optimal mixture ratio of the admission and fuel injection.
The QOSII preheating system is used in the GW4D28 diesel engine. Its characteristic is that the system can switch
on quickly to preheat and can control the time when the preheatinig starts and ends with a thermometer

EN-3

GW4D28 Diesel engines-Engine assembly

Engine assembly
4

Disassembly sequence
1. transmission assembly and clutch assembly
2. radiator assembly
3. air intake guide
4. heater hose
5. engine control cable
6. preheating plug wire
7. fuel oil hose
8. oil pressure switch wire
9. air-conditioning compressor assembly
10. power steering pump assembly
11. vacuum pump hose
12. front exhaust pipe
13. engine bracket
14. engine assembly

12

10

Assembly sequence
13

Carry out assembly in the reverse order of

disassembly.

Disassembly
Preparation work

Break the grounding cable of the storage battery

Drain off coolant
1. Transmission assembly and clutch assembly
Raise the car and sustain it with a proper secure bench
(1) Transmission assembly
(a) Demount the propeller-shaft on the flange yoke
(b) Disassemble the transmission assembly
(2) Clutch assembly
Note: Dont leave the clutch liquid on the surface of the paint,
flush it away immediately
(1) platen assembly
(2) clutch plate assembly
(a) Use guiding plummet to avoid clutch plate assembly falling
freely
Guiding plummet:5-5825-3001-0
(b) Mark on the flywheel and the platen flange for alignment when
mounting
(c) Release platen assembly fixing bolts, detach clutch assembly

EN-4

GW4D28 Diesel engine-Engine assembly

2.

Radiator assembly
(a) Demount the upper and lower hoses of the radiator
(b) Disassemble overflow tank hose
(c) Disassemble the radiator assembly

3.
4.

Air intake guide

Heater hose

5.

Engine control cable

Release the cable bracket fixing bolts and demount the valve
control cable from the control lever of the injection pump

6.
7.

Preheating plug wire

Fuel hose

Disassemble the fuel inlet hose and oil return hose

8. Oil pressure switch wire
9.

Air-conditioning compressor assembly

(a) Release the air-conditioning compressor adjusting bolts
and then disassemble the driving belts
(b)

Disassemble the magnetic clutch wire connector

(c)

Unscrew the air-conditioning compressor fixing bolts,

remove the air-conditioning compressor assembly

10. Power steering pump assembly

(a)

Unscrew the power steering pump adjusting bolts and

then disassemble the driving belts

(b) Disassemble the inlet hose and oil return hose of the
power steering pump
(c) Unscrew the fixing bolts of the power steering remove
the power steering pump assembly
11. Vacuum pump hose
12. Front exhaust pipe
(a) Demout the fixing bolts of the front exhaust pipes from
the exhaust manifold
(b) Demout the stay bolts of the front exhaust pipes
(c) Demout the fixing nuts of the front exhaust pipes

GW4D28 Diesel engine-Engine assembly

EN-5

13. Engine bracket

Disassemble the engine bracket and engine jaw pads from both
sides of the housing.

14. Engine assembly

(a) Lift the engine with a crane carefully
(b) The front should be higher than the rear after lifting the
engine
(c) Take care not to crash any oil pipe, break pipe and so on
when taking out the engine assembly

Assembly
1.

Engine assembly

2.

Place the engine with the crane

Engine bracket
Install the engine bracket, and screw the bracket fixing bolts to
the specified torque
Screw down torque: 40N
m

3.

Front exhaust pipe

(a) Connect the front exhaust pipes and screw the fixing nuts
of the front exhaust pipes to the specified torque
67N
m screw down torque :67N
m
(b) Screw the front exhaust pipe bracket bolts to the speci-

4.

5.

fied torque
40N
m screw down torque :40N
m
Vacuum pump hose

Power steering pump assembly

(a) Mount the power steering pump and hose bracket
19N
m the screw down torque to screw the fixing
bolts of
the power steering pump:19 N
m
(b) Mount driving belts of the power steering pump and
adjust the belt tightening . Check the wear or damage of
the belts, change them if necessary
(c)

Press the middle of the driving belts with 98N force;

check the flexibility of each belt
(8-12)mm standard value of the flexibility :( 8-12) mm

EN-6

GW4D28 Diesel engine- Engine assembly

6.

Air-conditioning compressor assembly

(a)

Mount the air-conditioning compressor and screw the

fixing bolts to the specified torque
screw down torque :19N

(b) Connect the wire connector of the magnetic clutch

(c) Mount driving belts of the air-conditioning compressor
and adjust the belt tightening
Check the wear or damage of the belts, change them if
necessary
(d) Press the middle of the driving belts with 98N force;
check the flexibility of each belt
standard value of the flexibility :( 8-12) mm

7.

Oil pressure switch wire

8.

Connect the wire connector of the oil pressure switch

Fuel hose
Connect the fuel inlet hose and oil return hose, and then screw

9.

the turnbuckle firmly

Preheating plug wire
Connect the wire connector of the preheating plug

10. Engine control cable

(a) Install the valve control cable to the control lever of the
injection pump
(b) Switch the valve lever to full close position and strain the
control cable in the direction the arrow shows, eliminate
any relaxation
(c) Screw the fixing bolts of the valve cable bracket

11. Heater hose

Connect the heater hose and then screw the turnbuckle firmly
12. Air intake guide
Connect the air intake guide and then screw the turnbuckle
firmly.

13. Radiator assembly

(a) Mount the radiator assembly
(b) Connect the upper and lower hoses of the radiator
(c) Connect the overflow tank hose
14. Transmission assembly and clutch assembly
(see page EM-31)

EN-7

GW4D28 Diesel engine- Engine assembly

Engine assembly
1

Disassembly sequence
1. air intake guide
2. fan guide shield
3. engine jaw pad

Assemble in the reverse

order of disassembling.

Disassembly
Preparation work

Break the grounding cable of the storage battery

Drain off coolant
1. Air intake guide
Demount the air intake guide

2.

Fan guide shield

(a) Disassemble the fan guide shield
(b) Demount the upper and lower hoses of the radiator

3. Engine jaw pad

(a)

Disassemble the bolts connecting the engine jaw pad and

frame

(b)

Disassemble the fixing nuts of the engine jaw pad from

the side of the engine bracket

(c)

Lift the engine to disassemble the engine jaw pad

EN-8

GW4D28 Diesel engine-Engine assembly

Assembly
1.

Engine jaw pad

(a) Lift the engine to mount the engine jaw pad
(b) Tight the engine jaw pad fixing nuts and connecting bolts
to the specified torque
screw down torque of the engine jaw pad fixing nuts:
82N.m
screw down torque of the bolts connecting the engine jaw pad and frame: 40N.m

2.

Fan guide shield

3.

Install the fan guide shield

Air intake guide
(a) Install air intake guide
(b) Connect the grounding cable of the storage battery
(c) Add coolant
(d) Start the engine and check whether there is leakage of the
coolant

EN-9

GW4D28 Diesel engine-Intake manifold

Intake manifold

Disassembly sequence
1. air intake guide
2. crankcase vent hose
3. fuel injection pipe
4. oil measuring scale guide pipe
5. oil radiator cooling water pipe
6. intake manifold

Assembly sequence
2

Carry out assembly in the reverse order

of disassembly

Disassembly
Preparation work
Break the grounding cable of the storage battery
Drain off coolant
1.
2.

Air intake guide

Crankcase vent hose

3.

Fuel injection pipe

(a) Release the turnbuckle of the fuel injection pipe
(b) Unscrew the conical nuts at a side of the injection pump
(c)

4.

Unscrew the conical nuts at the side of the injector,

disassemble the fuel injection pipes and put them aside

Oil measuring scale guide pipe

Unscrew the fixing bolts and disassemble the oil measuring
scale guide pipes

5. Oil radiator cooling water pipe

(a) Unscrew the water pipes bracket bolts
(b) Disassemble the oil radiator cooling water pipes
6. Intake manifold
Unscrew the fixing bolts and nuts of the intake manifold

EN-10

GW4D28 Diesel engine-Intake manifold

Assembly
1.

Intake manifold
Screw the fixing bolts and nuts of the intake manifold tight to
the specified torque
screw down torque :19N
m

2.

Oil radiator cooling water pipe

(a) Assemble the oil radiator cooling water pipes
(b) Screw the water pipe bracket bolts behind the cylinder

3.

cover
Oil measuring scale guide pipe
Assemble the oil measuring scale guide pipes and tight them
together with the intake manifold

4.

Fuel injection pipe fuel injection pipe

(a) Connect the fuel injection pipe and screw the conical nuts
to the specified
screw down torque :29N
m
(b) Assemble the turnbuckle of the fuel injection pipe to the
home position

5.

Crankcase vent hose

6.

Air intake guide

(a) Connect the grounding cable of the storage battery
(b)

Add coolant

(c) Start the engine and check whether there is leakage of the
coolant

GW4D28 Diesel engine-Intake manifold

EN-11

Exhaust manifold

Assembly sequence
1. front exhaust pipe fixing nut
2. fixing bolt of the front exhaust pipe
mounting bracket
3. heat insulation board
4. exhaust manifold

Assembly sequence
1

Carry out assembly in the reverse order

of disassembly

Disassembly
Preparation work

Break the grounding cable of the storage battery

1.

Front exhaust pipe fixing nut

Demount two fixing nuts from the joint of the intake manifold
and front exhaust pipe

2.

Fixing bolt of the front exhaust pipe mounting bracket

3. Heat insulation board

4. Exhaust manifold
Demount the fixing bolts and nuts of the exhaust manifold, and
then disassemble the exhaust manifold and its sealing washer.

EN-12

GW4D28 diesel engine-Exhaust mainfold

Assembly
1.

Exhaust manifold
Screw the fixing bolts and nuts of the exhaust manifold tight
to the specified torque
screw down torque :26N
m

2.

Heat insulation board

Install the heat insulation board and tight the fixing bolts to the
specified torque
screw down torque :19N
m

3.

Front exhaust pipe mounting bracket fixing bolt

Tight the bracket fixing bolts to the specified torque
screw down torque :40N
m

4.

Front exhaust pipe fixing nut

(a) Screw the front exhaust pipe fixing nuts to the specified
torque
screw down torque :67N
m
(b) Connect the grounding cable of the storage battery

GW4D28Diesel engine- Cylinder cover cap

EN-13

Cylinder cover cap

2
1

Disassembly sequence
1. crankcase vent hose
2. cylinder cover cap
3. cylinder cover cap seal.ring

Assembly sequence
Carry out assembly in the reverse order of disassembly

Disassembly

Preparation work
Break the grounding cable of the storage battery
1. Crankcase vent hose
Remove the crankcase vent hose from the intake elbow
2. Cylinder cover cap
3. Cylinder cover cap seal ring

Assembly
1.

Cylinder cover cap seal ring

2.

Cylinder cover cap

(a) Oil the rocker arm and valve spring
(b) Install the cylinder cover cap seal ring to the cylinder cover cap
(c) The seal ring must be flat and non-destructive
(d) Tight the fixing bolts of the valve head cap to the specified torque.

screw down torque :13N
m

3. Crankcase vent hose
(a) Connect the crankcase vent hose to the intake elbows.
(b) Connect the grounding cable of the storage battery

EN-14

GW4D28 Diesel engine-Rockshaft assembly

Rockshaft assembly
2
1

Disassembly sequence
1. crankc ase vent hose
2. cylinder cover cap
3. rockshaft assembly

Assembly sequence
Carry out assembly in the reverse order of disassembly

Disassembly
Preparation work
Break the grounding cable of the storage battery
1.

Crankcase vent hose

2.
3.

Cylinder cover cap

Rockshaft assembly
Release the bracket nuts and fixing bolts of the rockshaft in turn,
detach the rockshaft assembly.

1.

Rockshaft assembly
(a) Release all the adjusting screws
(b)

Install the rockshaft to locate the big engine oil orifice

(4) in the frontage of the engine

(c)

Align the bracket bolts with the holes in the rockshaft,

and screw the bracket bolts to the specified torque...
The sequence is shown in figure
screw down torque :54N
m

(d)

Adjust the valve clearance

GW4D28 Diesel engine-Rockshaft assembly

EN-15

Valve clearance adjustment

(a) Rotate the crankshaft till the TDC ruling of the crankshaft
vibration damper pulley aligns with the timing pointer. At this
time either the first or the fourth cylinder piston locates at the top
dead center (TDC) of the upstroke.

(b) Check whether the bracket nuts of the rockshaft loosens.

Tight all the loosened rockshaft bracket nuts in the order shown
in figure before adjusting the valve clearance
Screw down torque :54N.m

(c) Check the clearance of the first cylinder intake valve and exhaust
valve tappet
If there is clearance between the first cylinder intake valve and
exhaust valve tappet, then the first cylinder locates at the top dead
center of the upstroke.
If the first cylinder intake and exhaust valve tappet are in the
compressed state, then the fourth cylinder piston locates at the top
dead center of the upstroke.
When adjusting the valve clearance of the first or the fourth
cylinder, its piston must locate at the top dead center of the
upstroke.
valve clearance value (in cold condition):0.4mm
Top dead center of the first cylinder upstroke
Top dead center of the first cylinder
compression stroke

The bottom dead center of the fourth

cylinder compression stroke

(d) Release the adjusting screws of each valve shown in figure

(e) Insert a proper clearance gauge between the rocker arm and the
valve tappet end
(f) Rotate the valve clearance adjusting screw till the clearance
gauge is against some resistance.
(g) Screw the lock nuts tight
(h) Rotate the crankshaft 360

(i) Align the TDC ruling of the crankshaft vibration damper pulley
with the timing pointer
The fourth cylinder upstroke top dead center
(j) Adjust the other valve clearance shown in figure
2. Cylinder cover cap
Install the cylinder cover cap and tight the fixing bolts to the specified
torque
screw down torque :13N
m
3. Crankcase vent hose
Connect the grounding cable of the storage battery

EN-16

GW4D28 Diesel engine-Valve oil seal and valve spring

Valve oil seal and valve spring

Disassembly sequence
1. cylinder cover cap
2. rockshaft assembly
3. valve spring
4. valve oil seal

Assembly sequence
Carry out assembly in the reverse order of disassembly

Disassembly
Preparation work
1.

Break the grounding cable of the storage battery

Cylinder cover cap

2.

Rockshaft assembly
Release the bracket nuts and fixing bolts of the rockshaft,
remove the rockshaft assembly

3.

Valve spring
Compress the valve springs with a special tool and remove the
valve lock clamps
valve spring compressor: 9-8523-1423-0(J-29760)
Note:
Place away the disassembled valve springs in the order of the
cylinder serial numbers.

4.

Valve oil seal

Disassemble the valve oil seal with pliers
Note:
The disassembled valve oil seal should not be used again

GW4D28 Diesel engine-Valve oil seal and valve spring

EN-17

Assembly
1. Valve oil seal
Install new valve oil seals with a special tool
special tool: 5-8840-2033-0

2.

Valve spring
Mount a bracket to the valve spring
Note:

The painted end of the valve spring should be underneath

Pump compressed air into the cylinder from the preheating
plug hole to force the valve to be in its position

Install the valve lock clamp with a special tool
valve spring compressor: 9-8523-1423-0
J-29760

3. Rockshaft assembly
(see page EN-14

4.

Cylinder cover cap

(a) Oil the rocker arm and valve spring
(b)

Install the cylinder cover cap seal ring to the to the

cylinder cover cap .
The seal ring must be flat and non-destructive

(c) Install the cylinder cover cap and tight the fixing bolts
to the specified torque
screw down torque :13N
m
(d) Connect the crankcase vent hose
(e) Connect the grounding cable of the storage battery

EN-18

GW4D28 Diesel engine-Cylinder cover assembly and sealing washer

Cylinder cover assembly and sealing washer

11
3

Disassembly sequence

8
2
4
1

1. radiator hose
2. heater hose
3. engine wire
4. engine oil radiator cooling water pipe
5. by-pass hose
6. fuel injection pipe
7. oil return hose
8. crankcase vent hose
9. preheating plug connecting panel
10. engine oil measuring scale guide pipe
11. cylinder cover cap
12. rockshaft assembly
13. tappet
14. cylinder cover
15. cylinder cover sealing washer

Assembly sequence
Carry out assembly in the reverse order of
disassembly

Disassembly
Preparation work

Break the grounding cable of the storage battery

Drain off coolant
1.

Radiator hose
Remove the radiator hose from the side of the engine

2.

Heater hose
Remove the heater hoses from the engine oil radiator cooling
water pipes

3.

Engine wire
Remove the wire connector from the thermostat cap assembly

4.

Engine oil radiator cooling water pipe

(a) Disassemble the water pipe bracket fixing bolts in the
backside of the cylinder cover
(b)

Remove the engine oil radiator cooling water pipes

GW4D28 Diesel engine-Cylinder cover assembly and sealing washer

5.

By-pass hose

6.

Fuel injection pipe

EN-19

(a) Release the turnbuckle of the fuel injection pipe

(b) Release the conical nuts at the side of the injection pump
(c) Unscrew the conical nuts at the side of the injector and
disassemble the fuel injection pipes
Note:
Plug up the orifices of the injector and the delivery valve
7.

to prevent foreign substances from entering them.

Oil return hose

8.

Disassemble the oil return hose at the side of the injector

Crankcase vent hose
Remove the crankcase vent hose from the intake elbow

9.

Preheating plug connecting panel

10. Engine oil measuring scale guide pipe

Remove the engine oil measuring scale guide pipe from the
cylinder cover
11. Cylinder cover cap

12. Rockshaft assembly

Release bracket bolts of the rockshaft, a little each time. The
sequence is shown in figure
Note:
If the rockshaft bracket bolts are not unscrewed a little
each time, the rockshaft may be damaged
13. Tappet

EN-20

GW4D28 diesel engine-Cylinder cover assembly and sealing washer

14. Cylinder cover
Release the cylinder cover bolts, a little each time. The sequence is
shown in figure
Note:
If the cylinder cover bolts are not unscrewed a little each time,
it will go against the undersurface of the cylinder cover

4D28

Assembly
1.

Cylinder cover sealing washer

The selection of the cylinder cover sealing washer is decided by the bulging
that the top of the piston protrudes the upper surface of the block
To improve the performance of the engine, three kinds of washer of different
thickness are provided to select.
Select a proper washer according to the following methods
Clean the carbon on the piston top and the upper surface of the block before
measurement . And clean the surfaces mounted sealing washers
(1) The measurement of the bulging of the top of piston
(a) Measure the bulging of piston with a dial measuring gauge
(b) The measuring position of the bulging of the piston top refers to
the left figure
All the measuring positions should get as close as possible to the block
(c) Measure point 1),2),3),4)and calculate two differentials 1)-2)
and3)-4)of each cylinder
(d) Get the maximum from the four cylinders
(e) Select the assortment of the sealing washer needed according to
the maximum and the chart below
The thickness of 4D28 cylinder cover sealing washer
The No.of sealing washer
(A)
(B)
(C)

The piston
top bulging
0.758-0.813
0.813-0.859
0.859-0.914

mm

The thickness of
the sealing washer
1.50
1.55
1.60

Note:
The piston top bulging differential of the minimum and maximum
must not be over 1.0mm.
2.

Cylinder cover
(a) Install set pin of cylinder cover to the block
(b) Install the cylinder cover sealing washer and make the mark on
its top be upward
(c) Clean the fitting surface of the cylinder cover and the block,
mount the head slightly
(d) Oil the screws of the cylinder cover bolts and the fitting surfaces
(e) Tight the cylinder cover bolts to the specified torque according
to the serial numbers in the figure within three steps
the torque of the cylinder cover bolt
N
m
The first step
49

The second step

60-75

The third step

60-75

GW4D28 diesel engine-Cylinder cover assembly and sealing washer

EN-21

3. Tappet
Oil the tappet and insert it into the cylinder cover
4.

5.

Rockshaft assembly

see page EN-14

Cylinder cover cap

(a) Oil the rocker arm and valve spring
(b) Install the cylinder cover cap seal ring to the cylinder
cover cap
(c) The seal ring must be flat and non-destructive
(d)

Tight the fixing bolts of the valve head cap to the

specified torque.
screw down torque :13N
m

6.

Engine oil measuring scale guide pipe

Tight the fixing bolts of the engine oil measuring scale guide
pipe to the specified torque
screw down torque :19N
m

7.

Preheating plug connecting panel

8.

Crankcase vent hose

9.

Oil return hose

Install the oil return hose with a new copper washer

10. Fuel injection pipe

(a) Install the conical nut to the side of the injection pump
and the injector.
(b) Tight the conical nuts to the specified torque
screw down torque :29N
m
(c) Install the turnbuckles of the pipes under the specified
torque
11. By-pass hose

EN-22

GW4D28 Diesel engine-Cylinder cover assembly and sealing washer

12. Engine oil radiator cooling water pipe
Screw the water pipe bracket bolts to the specified torque
screw down torque :19N
m

13. Engine wire

Connect the wires of the coolant temperature sensor and the
thermometer assembly
14. Heater hose
Install the heater hose and then screw the turnbuckle firmly
15. Radiator hose
(a) Connect the radiator hose and then screw the turnbuckle
firmly
(b) Connect the grounding cable of the storage battery
(c) Add coolant
(d)

Start the engine and check whether there is leakage of

coolant

EN-23

GW4D28 Diesel engine-Timing gear

Timing gear

Disassembly sequence
1. fan guide shield
2. power steering pump driving belt
3. AC-generator driving belt
4. cooling fan assembly
5. crankshaft vibration damper pulley
6. acoustic hood
7. acoustic hood gasket
8. timing gear cover
9. timing gear pipe.
10. idle gear B
11. idle gear A
12. injection pump assembly
13. camshaft timing gear
14. crankshaft timing gear
2

Assembly sequence
Carry out assembly in the reverse order
of disassembly

Disassembly
Preparation work

Break the grounding cable of the storage battery.

Drain off coolant
1. Fan guide shield
2.

Power steering pump driving belt

Unscrew the bracket bolts and adjusting bolts of the power
steering pump and then disassemble the driving belts

3.

AC-generator driving belt

Release the bracket bolts (the lower side) of the AC-generator and
lock bolts of the adjustment plate and disassemble the driving
belts

4.

Cooling fan assembly

Disassemble the lock nuts, and disassemble the cooling fan
assembly and the water pump pulley

5.
6.

Crankshaft vibration damper pulley

Acoustic hood

7.

Acoustic hood gasket

8.
9.

Timing gear cover

Timing gear pipe.

EN-24

GW4D28 Diesel engine-Timing gear

10. Idle gear
B

(a) Measure the clearance of the camshaft timing gear and crankshaft timing gear before disassembling the idle gears
(b) Measure the axial clearance of the idle gears before disassembling them
Note:
On the details of the measurement of the gear clearance and
axial clearance, please refer to the following items
(1) Timing gear clearance measurement
(a) Mount a dial measuring gauge on the measured timing gear
Fix the measured gear and gears connecting to it
(b) Hunt the measured gear to the left and right as much as possible
Obtain the reading of the dial measuring gauge
If the measured value exceeds the specified limit, the timing
gear must be replaced
timing gear clearance
Standard
0.10-0.17

mm
Limitation
0.30

(2) Idle gear
A
axial clearance measurement

Insert a clearance gauge between the idle gears and stop ring
to measure its axial clearance
If the measured value exceeds the specified limit, then the stop
ring must be replaced
timing gear clearance
Standard
0.07

mm
Limitation
0.20

11. Idle gear
A

12. Injection pump assembly
(a)

(a)

Disassemble six injection pump bracket bolts 1) from the

timing gear housing

Disassemble injection pump rear bracket bolts 2)from the

injection pump bracket 3)

(b) Disassemble injection pump rear bracket bolts 4) and bracket

5) from the housing

(c) Pull out the injection pump and the injection pump timing gear
together towards the backside of the engine
Note:

Plug up the orifices of the injection pump and delivery valve

with cap or its equivalent to prevent foreign substances from
entering them

EN-25

GW4D28 Diesel engine-Timing gear

13. Camshaft timing gear

(a) Measure the axial clearance of camshaft with a dial measuring gauge
Do this work before disassembling camshaft timing gear
If the clearance of the camshaft exceeds the specified limit, the
thrust plate must be replaced.
camshaft axial clearance
Standard
0.050-0.114

mm
Limitation
0.20

(a) Unscrew camshaft timing gear bolts from the camshaft.

Note:
Keep the camshaft fixed from rotating
(b)

Pull the camshaft timing gear2)out with general utility puller 1)

general utility puller: 5-8521-0002-0

(c)

Disassemble the thrust plate3)

14. Crankshaft timing gear

Assembly
1. Crankshaft timing gear
(a) Install crankshaft timing gear
(b)

Install the crankshaft timing gear 2) with crankshaft fixing

tool 1) The mark
X-X
of the crankshaft timing gear must
be outward
crankshaft gear fixing tool: 5-8522-0020-0

2. Camshaft timing gear

(a) Mount the thrust plate to the housing
(b)

Screw the fixing bolts of the thrust plate to the specified torque
screw down torque :19N
m

(c)

Install the camshaft timing gear to the camshaft

The mark
Y-Y
of the camshaft timing gear must be
outward

(d)

Tight the fixing bolts of the camshaft timing gear to the

specified torque
screw down torque: 85N
m

3. Injection pump assembly

(a) Install the O-ring 1)to the injection pump flange 2)
(b) Install the injection pump to the timing gear housing
Align the mark
V-V
of the idle gear
B
3) with the mark

V
of the injection pump timing gear 4)

EN-26

GW4D28 Diesel engine-Timing gear

(c) Tight six injection pump bracket bolts5)temporarily
After screwing the injection pump rear bracket bolts,
tight the bracket bolts of the injection pump at last

(d) Install the injection pump rear bracket 6) and rear bracket
bolt 7)to the housing
Install the rear bracket bolt 8) to the injection pump

bracket 9)
Screw the rear bracket bolts 7) and 8)to the specified
torque after tighting the injection pump nuts

(e) Tight the injection pump nuts to the specified torque

screw down torque :15N
m

(f)

Screw the injection pump bracket bolts to the specified

torque
screw down torque :19N
m

4.

Idle gear
A

(a) Oil the idle gear
A
and its shaft
The oil orifice in the idle gear shaft must be upward
(b)

Place the gear
A
to direct the marks
X
and
Y

toward the frontage of the engine

(c) Align the mark
X
of the idle gear with the mark
XX
of the crankshaft timing gear1)
Align the mark
Y
of the idle gear
A
with the mark

Y-Y
of the camshaft timing gear 2)
(d) Install the stop ring and idle gear bolts to the housing.
The oil orifice in the stop ring must be upward. The
chamfer of the stop ring must be outward
(e)

Screw the idle gear
A
fixing bolts to the specified

torque
screw down torque :19N
m

5.

Idle gear
B

(a) Cover the idle gear
B
and its shaft with oil
(b)

Align the mark
Z
of the idle gear
B
3) with the
mark
Z-Z
the idle gear
A
4)

(c) Tight the idle gear Bfixing bolts to the specified torque
screw down torque:76N
m

GW4D28 Diesel engine-Timing gear

EN-27

6. Timing gear pipe.

(a)

Install the timing gear pipe to the timing gear housing and

idle gear
A

(b) Tight the pipe eye bolt 1) and fixing bolt 2) to the
specified torque
screw down torque of the pipe eye bolt:13N
m

7.

Timing gear cover

(a) Align set pin of the timing gear cover with the timing gear
(b)

cover, and then mount the timing gear cover

Screw the fixing bolts of the timing gear cover to the
specified torque
screw down torque :19N
m

8.

Acoustic hood gasket

9.

Acoustic hood

10. Crankshaft vibration damper pulley

Tight the fixing bolts of the crankshaft vibration damper pulley
to the specified torque
screw down torque :206N
m
Note:
Fix the flywheel ring gear to prevent the crankshaft from
spinning when tighting the bolts of the crankshaft vibration damper pulley
11. Cooling fan assembly
Install the water pump pulley and the cooling fan assembly to
the water pump, tight the lock nuts to the specified torque
screw down torque :8N
m
12. AC-generator driving belt
(a) Mount driving belts of the AC-generator and adjust the
belt tightening
(b) Press the middle of the driving belts with 98N force
driving belt flexibility :(8-12)m
13. Power steering pump driving belt
(a)

Mount driving belts of the power steering pump and

adjust the belt tightening

(b) Press the middle of the driving belts with 98N force
driving belt flexibility :(8-12)mm
14. Fan guide shield
(a) Install the fan guide shield and overflow tank hose.
(b) Add coolant
(c)

Start the engine and check whether there is leakage of

coolant

EN-28

GW4D28 Diesel engine-Engine oil filter assembly

Engine oil filter assembly

Disassembly sequence

1. water tube hose

2. engine oil filter
3. engine oil radiator fixing nut
4. engine oil radiator

Assembly sequence
Carry out assembly in the reverse order of
disassembly

Disassembly
Preparation work

Break the grounding cable of the storage battery

Drain off coolant

Place a container under the engine oil filter to collect engine oil
1.

Water tube hose

Release the intake and exhaust hoses of the engine oil radiator

2.

Engine oil filter

Disassemble the engine oil filter with a filter wrench

3.

filter wrench: 5-8840-0200-0

Engine oil radiator fixing nut

4.

Engine oil radiator

Check
(1)

Safety valve

(a) Install an engine oil pressure gauge in engine oil passage

near the engine oil filter
(b)

Start the engine to check the opening pressure of the

safety valve
pressure:(422-461) kPa

GW4D28 Diesel engine-Engine oil filter assembly

EN-29

(2) Engine oil radiator

Check whether there is leakage of the radiator water
channel
(a) Plug up one end of the engine oil radiator water channel
(b) Submerge the engine oil radiator into water. Aerate the
other end of the engine oil radiator water channel with
compressed air (19.60kPa), if there are bulbs rising to the
water surface, that proves the water channel leaks.

Assembly
1.

Engine oil radiator

Install the O ring to the engine oil filter and assemble the engine

2.

oil radiator
Engine oil radiator fixing nut
Screw the engine oil radiator fixing nuts to the specified torque
screw down torque :29N
m

3. Engine oil filter

(a) Oil the O-ring of the engine oil filter with a thin layer
(b) Screw the new engine oil filter into the engine oil filter base
manually till the sealing area is oppressed to the O-ring
(c) Screw the engine oil filter 1.25 turns more with a filter
wrench

4. Water tube hose

(a) Connect the intake and oil return hose of the engine oil
radiator
(b) Connect the grounding cable of the storage battery
(c) Add coolant
(d) Start the engine and check whether there is leakage of the
engine oil radiator

EN-30

GW4D28 Diesel engine- Flywheel and transmission primary shaft front-bearing

Flywheel and transmission primary shaft front-bearing

Disassembly sequence
1. transmission assembly and clutch assembly
2. transmission primary shaft front-bearing
3. flywheel

Assembly sequence
Carry out assembly in the reverse order of disassembly

Disassembly
Preparation work
Break the grounding cable of the storage battery
1. Transmission assembly and clutch assembly
Raise the car and sustain it with a proper secure bench
(1) Transmission assembly
(a) Demount the propeller-shaft on the flange yoke
(b) Remove the transmission assembly
(2) Clutch assembly
Note: Dont leave clutch liquid on the paint surface, flush
it away immediately
1) Platen assembly
2) Clutch plate assembly
(a) Use guiding plummet to avoid clutch plate assembly
falling freely
guiding plummet
5-5825-3001-0
(b) Mark on the flywheel flange and the platen flange for
alignment when mounting
(c) Release platen assembly fixing bolts, remove clutch
assembly
2.

Transmission primary shaft front-bearing

Disassemble the transmission primary shaft front-bearing
with a bearing extractor and a sliding hammer transmission
primary shaft front-bearing extractor: 5-8840-2000-0
sliding hammer: 5-8840-0019-0

GW4D28 Diesel engine- Flywheel and transmission primary shaft front-bearing

3.

EN-31

Flywheel
(a) Assemble flywheel retaining device
(b)

Unscrew fixing bolts of the flywheel and then disassemble the flywheel

Assembly
1.

Flywheel
(a) Cover the flywheel bolts with engine oil
(b) Tight flywheel bolts to the specified torque in two steps
with angle-tight method, and the sequence is shown in
figure.
flywheel bolt torque N
m

The first step(pre-tighten torque)

59

2.

The second step(final bolt torque)

60-90

Transmission primary shaft front-bearing

Install the transmission primary shaft front-bearing with a
bearing assembler
bearing assembler of the transmission primary shaft front
bearing:5-8522-0024-0

3.
(1) Clutch
1) Clutch plate assembly
(a) Cover multiple spline of clutch plate hub with multifunctional molybdenum disulphide grease
(b) Mount the clutch plate assembly with a guiding plummet
guiding plummet
5-5825-3001-0

2) Platen assembly
(a) Tight platen assembly fixing bolts in the order shown in
figure to the specified torque
screw down torque :18N
m
(b) Detach the guiding plummet
Note:If a new platen is installed,after tighting the planten
fixing bolts to the specified torque,the wire guarding the
diaphragm spring must be detached
(2) Transmission assembly
(a) Assemble the transmission assembly
(b) Install the propeller-shaft

EN-32

GW4D28 Diesel engine- Engine oil pump assembly

Engine oil pump assembly

Disassembly sequence
1. vacuum pump engine oil hose
2. enginge bracket bolt
3. stiffening plate and rubber packing
4. oil pan
5. engine oil pump assembly

Assembly sequence
Carry out assembly in the reverse order
of disassembly

Disassembly
Preparation work
Break the grounding cable of the storage battery
Lift the car
Drain off engine oil
Note:
Install a new washer of oil drain plug
oil drain plug screw down torque:83N
m
1. Oil hose of vacuum pump
(a) Remove the engine oil hose
from the oil pan
(b) Remove the engine oil hose
from the housing
engine oil hose

engine oil hose

2. Enginge bracket bolt

Release engine bracket bolts and disassemble the engine
bracket
3. Stiffening plate and rubber packing
(a) Disassemble exhaust manifold bracket
(b) Disassemble stiffenning plate from the oil pan
(c)

Take out rubber packing

4. Oil pan
(a) Lift the engine for about 50 mm
(b)
5.

Remove the oil pan from the housing

Engine oil pump assembly

Remove the engine oil pump assembly from the housing

GW4D28 Diesel engine- Engine oil pump assembly

EN-33

Assembly
1.

Engine oil pump assembly

(a) Oil the O-ring of oil hose and install the O-ring to the Oring groove of the housing
(b) Install the engine oil pump assembly with engine oil hose
to the housing,and tight the fixing bolts to the specified
torque
screw down torque :19N
m
(c) Tight sleeve nut to the specified torque
screw down torque:25N
m

2.

Oil pan assembly

(a)

Cover the fifth bearing cap arched area ,gutter and timing
gear housing arched area with fluid sealant recommended
or its equivalent

(b) Install the posterior lip of the sealing washer into the fifth
gutter
(c) Make sure the lip is appressed to the gutter
(d)

Install the oil pan to the housing

(e) Screw the oil pan fixing bolts to the specified torque
screw down torque:19N
m

3.

Stiffening plate and rubber packing

(a) Assemble the rubber packing
(b) Install the stiffening plate and tight the fixing bolts to the
specified torque Screw down torque of the bolts at the
side of theengine:37N
m
Screw down torque of the bolts at the side of theclutch
housing:78N
m
(c) Mount exhaust manifold bracket

4.

Enginge bracket bolt

(a) Install the engine bracket ,and screw the bracket bolts to
the specified torque
Screw down torque :40N
m
(b) Connect the engine oil hose to the oil pan and housing

5. Vacuum pump engine oil hose

(a) Connect the grounding cable of the storage battery
(b)

Add coolant

(c) Add engine oil

(d) Start the engine and check whether there is leakage of the
coolant

EN-34

GW4D28 Diesel engine- Oil pan assembly

Oil pan assembly

Disassembly sequence
1. vacuum pump engine oil hose
2. enginge bracket bolt
3. stiffening plate and rubber packing
4. oil pan assembly

Assembly sequence
Carry out assembly in the reverse order
of disassembly

Disassembly
Preparation work

Break the grounding cable of the storage battery

Lift the car

Drain off engine oil

Note:

Install a new washer of oil drain plug

oil drain plug screw down torque:83N
m

1. Vacuum pump engine oil hose

(a)

Disassemble the engine oil hose
from the oil pan

(b)

Disassemble the engine oil hose
from the housing

engine oil
hose

engine oil hose

2. Enginge bracket bolt

Release engine bracket bolts ,and remove engine bracket

3. Stiffening plate and rubber packing

(a) Disassemble exhaust manifold bracket
(b) Disassemble the stiffenning plate from the oil pan
(c)

Take out the rubber packing

GW4D28 Diesel engine- Oil pan assembly

4.

EN-35

Oil pan assembly

(a) Lift the engine for about 50 mm
(b) Disassemble the oil pan from the housing

Assembly
1.

Oil pan assembly

(a) Cover the fifth bearing cap arched area ,gutter and timing
gear housing arched area with recommended fluid sealant or its equivalent

(b) Install the posterior lip of the sealing washer into the fifth
gutter
(c) Make sure the lip is appressed to the gutter
(d) Install the oil pan to the housing
(e)

Screw the fixing bolts of the oil pan to the specified

torque
screw down torque :19N
m

2. Stiffening plate and rubber packing

(a) Take out the rubber packing
(b) Install the stiffening plate and tight the fixing bolts to the
specified torque
Screw down torque of the bolts at the side of the
engine:37N
m
Screw down torque of the bolts at the side of the
clutch housing:78N
m
3.

Enginge bracket bolt

(a) Iinstall the engine bracket ,and screw the bracket bolts to
thespecified torque
screw down torque :40N
m

4.

(b) Connect the engine oil hoses to the oil pan and housing
Vacuum pump engine oil hose
(a) Connect the grounding cable of the storage battery
(b) Add engine oil
(c) Add coolant
(d) Start the engine and check whether there is leakage of the
coolant

EN-36

GW4D28 Diesel engine-Camshaft and tappet stem

Camshaft and tappet stem

Disassembly sequence
1. transmission assembly and clutch assembly
2. engine assembly
3. cylinder cover assembly
4. camshaft timing gear
5. oil pan assembly
6. engine oil pump assembly
7. camshaft and tappet stem

Assembly sequence
Carry out assembly in the reverse order of disassembly

Disassembly
Preparation work

Break the grounding cable of the storage battery

Drain off coolant

Drain off engine oil

Note:

Install a new copper washer of oil drain plug

oil drain plug screw down torque:83N.m
1.

Transmission assembly and clutch assembly

see page EN-30

2. Engine assembly

see page EN-33

3. Cylinder cover assembly

see page EN-18

4.

Camshaft timing gear

(1)

Cooling fan assembly

Release the lock nuts ,and disassemble cooling fan assem-

bly and water pump pulley

(2) Crankshaft vibration damper pulley
(3)

Acoustic hood

(4)
(5)

Acoustic hood gasket

Timing gear cover

EN-37

GW4D28 Diesel engine-Camshaft and tappet stem

(6)

Camshaft timing gear

(a)

Measure the camshaft axial clearance with a dial measuring gauge Do this work before disassembling camshaft
timing gear If the camshaft clearance exceeds the specified limit, the thrust plate must be replaced.

camshaft axial clearance

Standard
0.050-0.114

(b)

mm
limitation
0.20

Remove camshaft timing gear bolts from the camshaft.

Note:
Keep the camshaft fixed from spinning
(c) Pull the camshaft timing gear
out with general utility
puller

general utility puller: 5-8521-0002-0
(d)

Disassemble the thrust plate3)

5.
(b) Disassemble the stiffening plate and rubber packing from
two sides of the oil pan
(c) Disassemble the oil pan bolts and remove the oil pan from

engine oil hose

the housing
6.

Engine oil pump assembly

Remove the engine oil pump assembly from the housing

engine oil hose

7.

Camshaft and tappet stem

(a) Remove the camshaft from the housing
Take care not to damage the camshaft bearings

(b)

Take out the tappet stem from the housing tappet stem
hole

EN-38

GW4D28 Diesel engine-Camshaft and tappet stem

Assembly
1.

Camshaft and tappet stem

(a) Oil the tappet stem and tappet stem mounting hole
(b) Place the tappet stem according to the position mark made
when disassembling(if the tappet stem is ready to use again)
Note:
The tappet stem must be mounted before assembling the
camshaft

(c) Oil the camshaft and camshaft bearings

(d) Install the camshaft to the housing
Take care not to damage the camshaft bearings

2.

Engine oil pump assembly

(see page EN-33)

3.

Oil pan assembly

(see page EN-33)

4.

Camshaft timing gear

(1) Camshaft timing gear
(a) Install the thrust plate to the cylinder and screw the fixing
bolts to the specified torque
screw down torque :18N
m
(b) Install the camshaft timing gear to the camshaft
(c)

The mark
Y-Y
of the camshaft must be outward

Align the mark
V-V
of the idle gear
B
with the
mark
V
of the injection pump timing gear

(d) Align the mark
Z
of the idle gear
B
with the mark

Z-Z
of the idle gear
A

(e)

Place the position marks
X
and
Y
of idle gear

A
to direct them toward the frontage of the engine

(f)

Align the mark
X
of the idle gear
A
with the mark

X-X
of the crankshaft timing gear

(g) Align the mark
Y
of the idle gear
A
with the mark

Y-Y
of the camshaft timing gear
(h) Tight the camshaft timing gear fixing bolts to the specified
torque
screw down torque :85N
m

GW4D28 Diesel engine-Camshaft and tappet stem

EN-39

(2) Timing gear cover

(a) Align the timing gear cover set pin with the timing gear
cover,and then assemble the timing gear cover
(b) Screw the fixing bolts of the timing gear cover to the
specified torque
Screw down torque: 19N
m
(3) Acoustic hood gasket
(4) Acoustic hood

(5) Crankshaft vibration damper pulley

Tight the crankshaft vibration damper pulley fixing bolts to
the specified torque
Screw down torque: 206N
m
Note:
Fix the flywheel ring gear to prevent the crankshaft from
spinning when tighting the crankshaft vibration damper
pulley bolts

(6) Cooling fan assembly

Install the water pump pulley and cooling fan assemlby
to the water pump in turn, and tight the lock nuts to the
specified torque
Screw down torque: 8N
m

5.

Cylinder cover assembly

see page EN-20

6.

Engine assembly

see page EN-3

7.

Transmission assembly and clutch assembly

see page EN-30

EN-40

GW4D28 Diesel engine-Piston and connecting rod assembly

Piston and connecting rod assembly

Disassembly sequence
1. cylinder cover assembly
2. oil pan assembly
3. engine oil pump assembly
4. connecting rod bearing cap
5. piston and connecting rod assembly

Assembly sequence
Carry out assembly in the reverse order
of disassembly

Disassembly
Preparation work
Break the grounding cable of the storage battery

Drain off coolant

Drain off engine oil

Note:
Install a new copper washer of oil drain plug
screw down torque: 83N
m
1.

Cylinder cover assembly

(see page EN-18)

2.

Oil pan assembly

3.

(see page EN-34)

Engine oil pump assembly

4.

(see page EN-32)

Connecting rod bearing cap
If the lower bearing of the connecting rod is to be reinstalled,
please tag each bearing with a label,recording the cylinder
serial number when disassembling and mounting position

GW4D28 Diesel engine-Piston and connecting rod assembly

5.

EN-41

Piston and connecting rod assembly

(a) Clean the carbon of the upper part of the cylinder wall
with a doctor knife before disassembling the piston and
connecting rod

(b) Move the piston to the top of the cylinder, push the end
of the rod with the shaft of a hammer or its equivalent,and
take out the piston and connecting rod.

(c) If the connecting rod upper bearing is to be reinstalled,

please tag each bearing with a label, recording the cylinder serial number when disassembling and mounting
position

(d) Clamp the rod with a jaw

Take care not to bruise the connecting rod
(e) Detach each piston ring with a piston ring expander
Do not try to detach piston ring with other tools
Expanding the piston ring with extravagance will reduce
the elasticity of the piston ring

(f)

Detach piston pin retainer with a long-nose plier

EN-42

GW4D28 Diesel engine-Piston and connecting rod assembly

(g)

Knock out the piston pin with hammer and copper bar
If the piston and piston pin are to be reinstalled,please tag
each bearing and piston pin with a label, recording the
cylinder serial number when disassembling and mounting position

Assembly
1.

Piston and connecting rod assembly

(a) Weigh each piston and connecting rod assembly
When selecting piston and connecting rod set,the weight
differentials of different cylinders while same sets should
be maintained in a specified range
Specified value:less than 3g
(b)

Clamp the rod with a jaw

Take care not to bruise the connecting rod

(c)

Install the piston pin retainer into the groove with a longnose plier

Note:
When changing the set of the piston/connecting rod,do
not change the set of the piston/piston pin.

(d)

Install the piston to the connecting rod

The forward mark=
at the top of the piston and the cast
mark
ISUZU

must be directed toward the same
direction

(e) Oil the piston pin and piston pin hole

Push the piston pin into the piston pin hole with fingers
till it contacts the piston pin retainer

GW4D28 Diesel engine-Piston and connecting rod assembly

(f)

EN-43

Press the retainer hard into the groove with fingers.

Check whether the connecting rod spins freely on
the pin

(g) Mount the piston ring with a piston ring expander The N
shaped mark on the gaseous ring must be upward.
The identification sign is shown in figure .

N mark
gaseous ring

(h) Install the piston ring in the following order

Oil ring
The oil ring with spiral expanding ring

The second gaseous ring

The first gaseous ring
The N shaped mark of the gaseous ring should be upward
when mounting the gaseous ring.

Note:
the first gaseous ring

the second gaseous ring

The surface with the mark should be upward when

assembling the gaseous ring
Install the spiral expanding ring into the oil ring groove,
and make sure there is no clearance at any side of the
spiral expanding ring before assembling the oil ring

oil ring

(i)

Cover the the piston surface with oil

(j)

Check whether the piston ring spins freely in its groove

(k) Place the piston ring joint shown in figure

the second gaseous ring

expanding ring

forward mark
oil ring

the first gaseous ring

EN-44

GW4D28 Diesel engine-Piston and connecting rod assembly

(1)

Eliminate carefully all kinds of sundries on the back of

rod bearings and fitting surface of the rod bearings

(m) Cover the upper bearing surface with engine oil .

Cover the cylinder wall with engine oil

(n)

When installing the piston, the forward mark at the top

should be directed toward the frontage of the engine
Compress the piston ring with a piston ring compressor
piston ring compressor:5-8840-99018-0
J-8037

(o) Push the piston into the cylinder with hammers shaft,till
the connecting rod contacts the crankpin .
At the same time rotate the crankshaft till the crankpin
locates at the bottom dead center(BDC)
2.

Connecting rod bearing cap

(a) When assembling, the forward mark on the bearing
(b)

cap should be directed toward the frontage of the engine

Install the connecting bearing cap
Align the cylinder serial number mark on the rod
bearing cap with the cylinder serial
number mark on the connceting rod

forward mark

(a)

Cover the screws of the rod bearing cap bolts and the

fitting surfaces with engine oil

(b) Tight the rod bearing cap bolts to the specified torque
with angle-tight method in two steps,
Rod bearing cap nut torque
N
m
the first step(pre-tighten torque)
the second step(final torque)
45

60-90

Note:
Rotate the crankshaft manually and check whether
the crankshaft spins freely
3.
4.
5.

Engine oil pump assembly

(see page EN-33

Oil pan assembly

see page EN-33

Cylinder cover assembly
(see page EN-20)

EN-45

GW4D28 Diesel engine-Crankshaft front-seal

Crankshaft front-seal

Disassembly sequence
1. fan guide shield
2. power steering pump driving belt
3. AC-generator driving belt
4. cooling fan assembly
5. crankshaft vibration damper pulley
6. crankshaft front-seal

Assembly sequence
Carry out assembly in the reverse order
of disassembly

Disassembly
Preparation work
Break the grounding cable of the storage battery

1.

Drain off coolant

Fan guide shield

2.

Power steering pump driving belt

Unscrew the bracket bolts and adjusting bolts of the power

steering pump and then disassemble the driving belts
3.

AC-generator driving belt

Release the bracket bolt (the lower side) of the AC-generator
and lock bolts of the adjustment plate and detach the driving

4.

belts
Cooling fan assembly
Release lock nuts of the cooling fan,and detach the cooling fan
assembly and the water pump pulley

5.

Crankshaft vibration damper pulley

6.

Crankshaft front-seal
Knock the the oil seal around with plastic hammer and stocky
driver, and disassemble the front-seal from the gear cover.
Take care not to damage the front-seal fitting surface

EN-46

GW4D28 Diesel engine-Crankshaft front-seal

Assembly
1.

Crankshaft front-seal
(a) Install the front-seal
to the gear cover with an oil seal
assembler

Front-seal assembler:5-8840-2361-0
(b)

Pay attention to the mounting depth
of the oil seal in

figure
Depth value:1mm

2.

Crankshaft vibration damper pulley

Tight the crankshaft vibration damper pulley fixing bolts to the
specified torque
Screw down torque :206N
m
Note:
Fix the flywheel ring gear to prevent the crankshaft from
spinning when tighting the crankshaft vibration damper
pulley bolts

3.

Cooling fan assembly

Install the water pump pulley and the cooling fan to the water
pump, and tight the lock nuts to the specified torque
Screw down torque :8N
m

4.

AC-generator driving belt

Mount AC-generator driving belts and adjust belt tightening

See page EN-27

5.

Power steering pump driving belt

Mount power steering pump driving belts and adjust belt
tightening

See page EN-27

6. Fan guide shield
(a) Install the fan guide shield and overflow tank hose.
(b) Connect the grounding cable of the storage battery
(c) Add coolant
(d) Start the engine and check whether there is leakage of the
coolant

GW4D28 Diesel engine- Crankshaft rear-seal

EN-47

Crankshaft rear-seal

Disassembly sequence
1. transmission assembly and clutch assembly
2. flywheel
3. crankshaft rear-seal

Assembly sequence
Carry out assembly in the reverse order of
disassembly

Disassembly
Preparation work

Break the grounding cable of the storage battery
1. Transmission assembly and clutch assembly
(See page EN-30)

2. Flywheel
(a) Install flywheel retaining device
(b) Release flywheel fixing bolts and then disassemble the
flywheel

3.

Crankshaft rear-seal
Push the oil seal inward and at the same time assemble the
special tool shown in the figure to detach the oil seal
rear-seal detacher :5-8840-2360-0
Note:
Take care not to damage the crankshaft and rear-seal
base when disassembling oil seal

EN-48

GW4D28 Diesel engine- Crankshaft rear-seal

Assembly
1.Crankshaft rear-seal
(a) Install the rear-seal to the block with an oil seal assembler
rear-seal assembler:5-8840-2359-0
Note:
Scrape the rust and chippings of the oil seal press-in part
thoroughly.
Pay attention to the press-in direction of the oil seal
(b) Install the joint of the special tool to the posterior end of
the crankshaft with two bolts
(c)

Install the oil seal to the outside circle of the joint (d)
Insert the sleeve into the joint part,and tight bolt (M12

1.75
L=70) till the joint butt end retains the sleeve.

(e) Disassemble the joint and sleeve

(f) Check oil seal fitted position after mounting the oil seal
Standard value:(12.2-12.8)mm

2.Flywheel
(a) Oil the flywheel bolts
(b) Tight the flywheel bolts to the specified torque with
angle-tight method in two steps,and the sequence is
shown in figure.
Flywheel bolt torque

3.

N
m

the first step(pre-tighten torque)

the second step(final torque)

59

60-90

Transmission assembly and clutch assembly

(See page EN-31)

GW4D28 Diesel engine-Crankshaft and main bearing

EN-49

Crankshaft and main bearing

Disassembly sequence
1. transmission assembly and clutch assembly
2. engine assembly
3. cylinder cover assembly
4. crankshaft timing gear
5. oil pan assembly
6. engine oil pump assembly
7. piston and connecting rod assembly
8. timing gear housing
9. water pump assembly
10. flywheel and engine body backboard
11. crankshaft rear-seal
12. crankshaft and main bearing

Assembly sequence
Carry out assembly in the reverse order of
disassembly

Disassembly
Preparation work

Break the grounding cable of the storage battery

Drain off coolant
1.

Drain off engine oil

Transmission assembly and clutch assembly

See page EN-30)

2.

Engine assembly

See page EN-3

3.

Cylinder cover assembly

See page EN-18

EN-50

GW4D28 Diesel engine-Crankshaft and main bearing

4.

Crankshaft timing gear

(See page EN-23

5.

Oil pan assembly

See page EN-34

6.

Engine oil pump assembly

See page EN-32

7.

Piston and connecting rod assembly

See page EN-41

8.

Timing gear housing

9.

Water pump assembly

10. Flywheel and engine body backboard

(a) Install flywheel retaining device
(b) Release fixing bolts of the flywheel and then disassemble
the flywheel
(c) Disassemble the engine body backboard

11. crankshaft rear-seal

Push the oil seal inward and at the same time assemble a special
tool shown in the figure to detach the oil seal
rear-seal detacher: 5-8840-2360-0
Note:
Take care not to damage the back plate and crankshaft
sealing surface when disassembling oil seal

12. Crankshaft and main bearing

(a) Disassemble main bearing cap and thrust plate

(b) Disassemble the crankshaft carefully
(c) Disassemble the the crankshaft upper bearing

Assembly
1.

Crankshaft and main bearing

(a)

There is an oil orifice and an oil groove in the upper

bearing,while nothing in the lower one

(b) Scrape off various foreign substancees on the bearings
(c) Cover the upper and lower bearings with new engine oil
Note:
Do not oil the back of bearings and fitting surfaces of the
bearings and the housing

GW4D28 Diesel engine-Crankshaft and main bearing

(d)

EN-51

Install the crankshaft main bearing to the housing and

main bearing cap .

The main bearing must be installed in the right position

(e) Assemble the crankshaft carefully

(f)

Cover the thrust plate with engine oil

(g) Install the thrust plate to the third maneton

The oil groove of the thrust plate must be directed toward
the crankshaft

(h) Cover the fifth bearing cap of the crankshaft with recommended fluid sealant or its equivalent,shown in figure

(i) Cover the fitting surfaces of fifth bearing cap and housing
with recommended fluid sealant or its equivalent,shown
in figure .
Note:
Before smearing liquid sealant,the main bearing fitting
surface must be clean from even a drop of engine oil .
Do not let fluid sealant block threaded holes and bearings
(j) The arrow mark at the top of each bearing cap must be
directed toward the frontage of the engine when mounting main bearing cap
(k) Oil each bolt of the crankshaft main bearing cap
(1) Tight the crankshaft main bearing cap bolts to the specified torque,a little each time,and the sequence is shown in
figure
Screw down torque: 167N
m
Note:
Rotate the crankshaft manually and check whether the
crankshaft spins freely

EN-52

GW4D28 Diesel engine-Crankshaft and main bearing

2.

Crankshaft rear-seal
(see page EN-48)

3.

Flywheel and engine body backboard

(a) Align the back plate with set pin of the housing
(b) Screw the back plate fixing bolts to the specified torque
screw down torque: 82N
m

(c)

Stop off the crankshaft with hardwood to prevent the

flywheel from spinning

(d) Oil the screws of the flywheel bolts
(e) Align the crankshaft set pin with flywheel set pin hole
(f)

Tight the flywheel bolts to the specified torque with

angle-tight method in two steps

The sequence is shown in figure.

Flywheel bolt torque

4.

N
m

the first step(pre-tighten torque)

the second step(final torque)

59

60-90

Water pump
Install the water pump assembly and tight the fixing bolts to the
specified torque
screw down torque: 20N
m

5.

Timing gear housing

(a) Install the timing gear housing to the housing
Do not distort the crankshaft front-seal
(b)

Screw the timing gear housing fixing bolts to the specified torque
screw down torque: 19N
m

(c)
6.
7.

Remove the bulging of the timing gear housing sealing

washer

Piston and connecting rod assembly

Engine oil pump assembly
(see page EN-33)

8.

Oil pan assembly

(see page EN-33)

9.

Crankshaft timing gear

(see page EN-25)

10. Cylinder cover assembly

(see page EN-20)
11. Engine assembly
(see page EN-5)
12. Transmission assembly and clutch assembl
(see page EN-31)

EN-53

GW4D28 Diesel engine-Housing

Housing

N
P

Disassembly sequence
1. transmission assembly and clutch assembly
2. engine assembly
3. cylinder cover assembly
4. AC-generator
5. engine bracket
6. engine oil filter assembly
7. timing gear
8. oil pan assembly
9. engine oil pump assembly
10. piston and connecting rod assembly
11. timing gear housing
12. water pump assembly
13. flywheel and engine body backboard
14. crankshaft rear-seal
15. crankshaft
16. camshaft and tappet stem
17. housing

R
Assembly sequence
Carry out assembly in the reverse order of
disassembly

Disassembly
Preparation work

Break the grounding cable of the storage battery

Drain off coolant

Drain off engine oil
Note:
Install a new copper washer of oil drain plug oil
drain plug screw down torque: 83N
m

EN-54

GW4D28 Diesel engine-Housing

1.

Transmission assembly and clutch assembly

(See page EN-30)

2. Engine assembly
(See page EN-3)
3.

Cylinder cover assembly

(See page EN-18)

4.

AC-generator
(a)Remove AC-generator wire connector
(b)Remove the engine oil hose
from the oil pan
(c)Remove the engine oil hose
from the housing

oil hose

(d)Remove AC-generator adjustment plate fixing bolts

(e)Remove AC-generator fixing bolts
oil hose

5.

Engine bracket
Remove the engine bracket from the housing

6.
7.

Engine oil filter assembly

see page EN-28

Timing gear

see page EN-23

8. Oil pan assembly
9.

see page EN-34

Engine oil pump assembly

see page EN-32

10. Piston and connecting rod assembly

see page EN-41

11. Timing gear housing
Release timing gear housing fixing bolts , and detach timing
gear housing and its sealing washer from the housing

GW4D28 Diesel engine-Housing

EN-55

12. Water pump assembly

(a)

Remove the water pump assembly fixing bolts and

detach the water pump assembly

(b) Detach the O-ring from the water pump

13. Flywheel and engine body backboard

(a) Install flywheel retaining device
(b) Release the flywheel fixing bolts and then disassemble
the flywheel
(c) Disassemble the engine body backboard

14. Crankshaft rear-seal

Push the oil seal inward and at the same time assemble a
special tool shown in figure to detach the oil seal
rear-seal detacher: 5-8840-2360-0
Note:
Take care not to damage the back plate and crankshaft
sealing surface when disassembling oil seal

15. Crankshaft
16. Camshaft and tappet stem

See page EN-37

17. Housing

Assembly
1.

Housing
Clean housing fitting surfaces,and check the blockage of the
water channel and oil passage

2.

Camshaft and tappet stem

(see pageEN-38)

3.

Crankshaft
(see pageEN-50)

EN-56

GW4D28 Diesel engine-Housing

4.

Crankshaft rear-seal

5.

(see page EN-48)

Flywheel and engine body backboard

6.

Water pump

7.

Timing gear housing

(see page EN-52)

8.

Piston and connecting rod assembly

(see page EN-42)

9.

Engine oil pump assembly

(see page EN-33)

10. Oil pan assembly
(see page EN-33)
11. Timing gear
(see page EN-25)
12. Engine oil filter assembly
(see page EN-29)

13. Enginge bracket

Mount the engine bracket ,and screw the bracket fixing bolts
to the specified torque
screw down torque :40N
m

14. AC-generator assembly

(a) Tight AC-generator fixing bolts temporarily
(b) Connect vacuum pump engine oil hose
to the oil pan
(c) Connect vacuum pump engine oil hose
to the housing

oil hose

(d)

Connect AC-generator wire connector

oil hose

15. Cylinder cover assembly

16. Engine assembly
(see page EN-5)
17. Transmission assembly and clutch assembly
(see page EN-31)

FU-1

Fuel system
Page
General .......................................................................
Maintenance and repair on the car .............................
Fuel filter assembly .....................................................
Filter element of the fuel filter ......................................
The injector .................................................................
The injector pump assembly .......................................
Oil injection timing adjustment ....................................
Parameters of the fuel injection pump .........................
Injecting fuel adjustment .............................................
The fuel tank ...............................................................
The fuel gauge ............................................................
The throttle valve control .............................................
Control line of the throttle valve ...................................
The accelerator pedal .................................................
The air filter .................................................................

FU-2
FU-6
FU-6
FU-7
FU-8
FU-11
FU-14
FU-15
FU-15
FU-16
FU-18
FU-19
FU-19
FU-20
FU-22

FU

FU-2

Fuel system-General

General
The following should be observed when being engaged in working on the fuel supply system:
(1)
(2)

Whenever the fuel supply system is working, earth wire of the battery should be cut off.
Dry chemical fire extinguishers (level B) should be kept around the work place.

(3)

Change all the removed oil pipes and attachments for new ones which are the same types as
the removed.

(4)

Before repairing parts of the fuel supply system, pressure in the pipelines should be released.

(5)

Do not repair the fuel supply system without reading instruction books or checking the
drawings on repairing.

The fuel oil flow

solenoid valve of cold starting device

injector
fuel cut solenoid valve

distributor injection pump

fuel filter

oil-and-moisture trap

fuel tank

The fuel supply system consists of a fuel tank, an Oil-and-moisture

trap, a fuel filter, an injector and an injection pump.
Fuel in the fuel tank flows through the Oil-and-moisture trap and
fuel filter (to filter off water and other impurities) and the injection
pump plunger. Some fuel is fed to the injector in an optimal time,
and then is injected to the cylinder with certain time, certain quality
and certain quantity.

FU-3

Fuel system-General

Injection pump

governor spring
fly block

idle spring
full load adjusting bolt

control lever
tension rod

control lever shaft

governor rod assembly

from the fuel filter
fuel cut solenoid valve

pressure control valve

plunger
oil outlet

to injector
drive shaft
delivery valve
control sleeve

injection pump
drive gear

plunger spring

cross block

cam plate

The Bosch distributor injection pump is used in the GW4D28 type

diesel motor. The fuel is fed to each injector uniformly by a to-andfro/rotary type plunger, which has nothing to do with the serial
numbers.
The governor, the fuel supply automatic advance and fuel pump are
all set inside the injection pump case. The injection pump which is
compact and light can run with high speed reliably.

FU-4

Fuel system-General

The fuel filter and Oil-and-moisture trap

start the injection pump
oil-and-moisture
trap

the fuel filter assembly

the case

drain level
float

filter element of the fuel filter

level sensor

drain plunger

There is a fuel filter with filter element and an Oil-and-moisture

trap, besides the distributor injection pump.
The interior of oil injection pump is lubricated by flowing fuel
oil. The fuel should be clean. Before fed to the injection pump, fuel
should flow through the fuel filter and the Oil-and-moisture trap in
order to remove water and other impurities in the fuel.
There is a float inside the Oil-and-moisture trap. When the float
rises to certain level, the warning lamp will give signals that it is time
to release water in the Oil-and-moisture trap.
The thin-film fuel injection pump is set on the top of Oil-andmoisture trap. It will be used when releasing the water and air.

FU-5

Fuel system-General

The injector

injector body

pressure adjusting washer

pressure adjusting spring of the injector

pressure adjusting spring seat
the injector

hold-down nut

The high pressure fuel, which is from the injection pump, is

injected to combustion chamber by the injector through the injection hole.
The hole-type injector with four injection holes is used in the
4D28 engine. The injector consists of injector body and injector
mated pair.
The high pressure fuel, which is from the injection pump, is
injected to combustion chamber.

FU-6

Fuel system-Maintenance and repair on the car

Maintenance and repair on the car

The fuel filter assembly

Disassemble order
1. fuel hose
2. fuel filter
3. oil-and-moisture trap

Assemble order
N

The assemble order is adverse to the

disassemble order.

Disassemble
Preparing work
Cut off the earth wire of battery.
1.

Fuel hose
(a) Disassemble the fuel hose of fuel filter.
(b) Plug the fuel hose end so the fuel can not overflow.

2.

Fuel filter
Disassemble the fix screws on the fuel filter bracket, then
disassemble the fuel filter.

3.

Oil-and-moisture trap

Assemble
1.
2.

Oil-and-moisture trap
Fuel filter
Assemble the fuel filter and tighten the fix screws on the
bracket.

3. Fuel hose
(a) Connect the fuel hose to fuel filter.
(b) Connect the earth wire of battery.
(c) Feed the fuel to fuel injection pump by using starinjection
pump and release air in the fuel supply system.

Fuel system-Maintenance and repair on the car

FU-7

Filter element of the fuel filter

Disassemble
Disassemble the filter element by filter wrench.
Filter wrench: 5-8840-0253-0 (J-22700)

Assemble
(a)

Clean the surface of filter element of fuel filter so the

filter element can be well seated.

(b) Paint thin motor oil on the O ring of new filter element.
(c) Inject fuel to new filter element to remove air.
(d) Tighten the new filter element, until the O ring contact
with the sealing surface. Be careful in order to prevent the
fuel overflow.
(e) Tighten the filter element with 1/3 to 2/3 of a circle by
using the filter wrench.
Filter wrench: 5-8840-0253-0 (J-22700)
Air release
(a) Operate the start injection pump so the air in the fuel
supply system will be pushed to injection pump.
(b) Loosen the bleeder screw of injection pump and control
the start injection pump until all air bubble be removed.
(c) Tighten the bleeder screw.
(d) Start the engine. If it were not started in 10 seconds,
repeat the releasing process.
(e) Make sure that there is not any fuel leakage and tighten
the cover of start injection pump.
Water release
water level indicatory light

(a) When water in the Oil-and-moisture trap achieves certain

level, the warning lamb will give signals. Release water
as the following procedure.
(b) Put a vinyl hose on the plunger.
(c) Loosen the plunger.
(d) Control the start injection pump several times to release
water.

loosen the plunger anticlockwise

(e) After releasing water, tighten the plunger.

(f) Control the start injection pump several times to check if
there is any fuel leakage.
(g) Examine the warning lamb is on or off.

FU-8

Fuel system-Maintenance and repair on the car

The injector

Disassemble order
1. high pressure oil pipe
2. oil return pipe
3. injector

Assemble order
The assemble order is adverse to
the disassemble order.

Disassemble
Preparing work
1.

Cut off the earth wire of battery.

High pressure oil pipe
(a) Loosen the high pressure oil pipe fastener.
(b) Loosen the conical nut of the injection pump.
(c) Loosen the conical nuts of the injection pump, and remove

2.

the high pressure oil pipe and keep it in place.

Oil return pipe

3.

Injector

Check and repair

(a) Install the injector on the tester.
(b) When the oil pressure is 18142.3KPa, check the injector
head there is any leakage.
Change it if there is any leakage.
Disassemble
1. Clamp nuts
2.

Injector nozzle matching parts

(a) Disassemble every part from the injector body.
(b) Label all the injector body and every part in order to set
back when assembled.
Notice:
Do not change the combination of injector body and its
parts.
(c) Put the injector into a tool pan filled with clean diesel in
order to guard dust.

Fuel system-Maintenance and repair on the car

3.
4.
5.
6.
7.

FU-9

Spacer ring
Pressure adjusting spring seat
Pressure adjusting spring
Pressure adjusting spacer
Injector body

Check and repair

Check the injector. If the injector is worn or damaged, it is
necessary to adjust, repair or change.
Check the injector mated pair
(a) Remove the injector valve from the injector valve body.
(b) Clean the injector valve and injector valve body by clean
fuel oil.
(c)

Check whether the injector valve can run smoothly or

not. If not, do repair it (refer to the following the grinding
program of injector mated pair)

The grinding program of injector mated pair

(a) Grind the injector valve
and injector valve body
by
chromic oxide and animal oil grinding paste
.
Notice:
Do not use too much chromic oxide or animal oil
grinding paste on the injector valve seat. Too much
grinding paste will damage the injector valve and inner
conical surface.
(b) After grinding, clean the injector valve and injector valve
body by clean diesel.

Check the injector valve and the injector valve body

Check the damage and distortion of the injector valve and
injector valve body.
If the injector valve and the injector valve body are damaged
or distorted, do change them.

Reinstall
1.
2.
3.
4.
5.
6.
7.

Injector body
Pressure adjusting spacer
Pressure adjusting spring
Pressure adjusting spring seat
Spacer ring
Injector mated pair
Clamp nuts
Tighten the clamp nuts to set torque.
Tightening moment: 69N
m

FU-10

Fuel system-Maintenance and repair on the car

Injector adjustment
(a) Install the injector on the tester.
(b)

Increase the test pressure and check the start condition

under set pressure.

Pressure: 18142KPa
(1) If the injector can not work under set pressure, adjust it
by adjusting spacer with suitable grade number.
Usable adjusting spacer

(2)

mm

Thickness range

0.50-1.50

Grade thickness

0.025

Adjusting spacer assembly

40

When one grade of the adjusting spacer is increased or

reduced, the start pressure of injector can reduce or
increase 369.71KPa.

Warning:
The testing liquid inside injector is injected under high
pressure so it will hurt skins easily. When testing the
injector, you should keep your hands far away the tester.

Assemble
1.

Injector
(a) Install the injector sealing washer
and the O ring
to
the injector body
.
(b) Paint motor oil inside the mounting hole of injector body
of the cylinder cover.
(c)

Install the injector body
, together with the pressure

plate
, on the cylinder cover and tighten the pressure
plate screws to set torque.
Tightening moment: 37N
m

2.
3.

Return pipe
High pressure oil pipe

Fuel system-Maintenance and repair on the car

FU-11

Injection pump assembly

P

Disassembly order
1. the fan assembly
2. fan wind scooper
3. power steering pump and air-conditioning
compressor belt
4. AC generator belt
5. sound barrier cover
6. spacer of sound barrier cover
7. air inlet guide pipe
8. control line of the injection pump
9. fuel hose
10. line group of the injection pump
11. high pressure oil pipe
12. injection pump assembly

Assembly order
The assemble order is adverse to the
disassemble order.

Disassemble
Preparing work
Cut off the earth wire of battery.
Release cooling liquid.
1.

The fan assembly

Loosen the screws and remove fan assembly and belt pulley of
water pump.

2.
3.

Fan wind scooper

Power steering pump and air-conditioning compressor belt
Loosen the adjusting screws of the power steering pump and
remove the belt.

4.

AC generator belt
Loosen the fixing screws (lower side) of AC generator and the
lock screws of adjusting plate, and remove the belt.

5.

Sound barrier cover

6.

Spacer of sound barrier cover

7.

Air inlet guide pipe

FU-12

Fuel system-Maintenance and repair on the car

8.

Control line of the injection pump

Disassemble the screws on the line bracket and remove the
control line.

9.

Fuel hose
Remove the fuel supply hose and return hose.

cold start solenoid valve

tachometer sensor

injection pump

10. Line group of the injection pump

Remove the tachometer sensor (with the tachometer), solenoid valve
of the cold start device (CSD) and the solenoid valve for fuel cut.
11. High pressure oil pipe
(a) Loosen the fastener of high pressure oil pipe.
(b) Remove conical nuts at the injection pump.

fuel cut-off solenoid

valve

(c) Remove the conical nuts at the injection pump and remove
the high pressure oil pipe.
Notice:
Do plug the holes on the injector body and delivery valve
body to guard the impurities.
12. Injection pump assembly
(a) Remove the fixing screws of injection pump.
(b)
(c)

Loosen the lock screws on the back bracket of injection pump.

Remove the fixing screws at the engine side.

(d) Pull the injection pump from the back of engine.

Notice:
Do cover the holes on the delivery valve body by rubber
lagging (or similar things) to guard impurities.

Assemble
1. Injection pump assembly
(a) Install checking holes at timing gear side of cam shaft of the
timing gear housing and at the timing gear side of injection pump.
(b) Rotate the crankshaft in clockwise direction. Check the
TDC mark on crankshaft belt pulley is aligning with the
pointer. Stop the piston of the first cylinder at the upper dead
center of the upstroke.
(c) Check 0 scale mark on the timing gear of crankshaft is
aligning with the pointer through the checking hole at the
crankshaft timing gear.
(d) Under the above conditions, align the 0 scale mark of
injection pump gear with the pointer and install the injection
pump assembly.
camshaft gear

injection pump gear

(e) Install the fixing screws of the injection pump and tighten
the screws to set torque.
Tightening moment: 19N
m

Fuel system-Maintenance and repair on the car

2.

FU-13

High pressure oil pipe

(a) Connect the high pressure oil pipes at injection pump side
and injector side, and tighten the conical nuts to set
torque.
Tightening moment: 29N
m
(b) Install oil pipe fastener at the original location.

3.

Line group of the injection pump

Fix the line group of the injection pump and connect with
switch.

4.

Fuel hose

5.

Connect the fuel inlet hose and the return hose.

Control line of the injection pump
(a) Connect the steel cable with the control rod on the engine.
(b) Leave the throttle lever at the oil complete-cut point and
tension the control line in the direction indicated by the
arrow, which can eliminate the relaxation.
(c) Tighten the screws on the throttle control line bracket.

air-conditioning compressor and

power steering pump driving belt

6.

Air inlet guide pipe

7.

Spacer of sound barrier cover

8.

Sound barrier cover

9.

AC generator belt
(a) Install the AC generator belt and adjust tightness of the belt.
(b) Apply a force whose value is 98N onto the middle part of belt.
Deflection of the belt: (8-10) mm
(c) Install fixing screws and tighten to set torque.
Tightening moment of the generator fixing
screws: 25N
m
Tightening moment of the adjusting plate: 19N
m

AC genarator and fan

driving belt

10. Power steering pump and air-conditioning compressor belt

(a)

Install the power steering pump and air-conditioning

compressor belt and adjust its tightness.

(b) Apply a force whose value is 98N onto the middle part of belt.
(c)

Deflection of the belt: (8-10) mm

Tighten the fixing screws of the power steering pump
and air-conditioning compressor to set torque.
Tightening moment: 27N
m

FU-14

Fuel system-Maintenance and repair on the car

11. Fan wind scooper
Install the fan wind scooper and overflow tank hose.
12. Fan assembly
(a) Install the belt pulley and cooling fan onto the water
pump, and tighten the lock screw to set torque.
Tightening moment:8N
m
(b)

Connect the earth wire of battery.

(c) Fill with coolant.

(d) Start the engine and check if there is leakage or not.

Fuel supply timing adjustment

(a) Locate the first cylinder at the top dead center.
(b) Remove the distributor top plug of injection pump.
(c) Remove cold start device by screwdriver.
(d)

Install a dial gauge, and preset it with 1mm.

Measuring instrument: 5-8840-0145-0

(e)

Locate the top dead center mark of belt pulley of the

crankshaft vibration damper at the position which is
about 45 degrees to the top dead center.

(f) Adjust the dial gauge to
0
position.

(g) Rotate the crankshaft a little to left and to right. Check the
indicator of dial gauge is at
0
stably.
(h) Rotate the crankshaft clockwise, and read the number on
the dial gauge under the following condition.
14
before the top dead center, the reading on the
dial gauge is 0.5mm
(i)

If the reading is abnormal, loosen the fixing screws of

injection pump and adjusting screws on the injection
pump bracket. When the reading of dial gauge achieves
certain value, tighten the fixing screws and nuts to set
torque.
Tightening moment of fixing nuts on the injection
pump: 24N
m
Tightening moment of fixing bolts on the injection
pump: 19N
m

(j) Remove the measuring gauge, and tighten the distributor

plug of injection pump to set torque.
Tightening moment: 17N
m
Notice:

Do use new copper washers when install the

injection pump plug.

Install the high pressure oil pipe.

Install the pipe fastener.

FU-15

Fuel system-Maintenance and repair on the car

Parameters of injector
Iem
engine type
injector(bisch) type
Start pressure of injector
Size of high pressure oil pipe
Inner diameter
Outer diameter
Length
Delivery pressure
Test fuel
Temperature of test fuel

sspecification
GW4D28
p type:KBAL-P001A
18142

kPa
mm

1.6

6.35
400
19.61
light diesel
48-52

kPa

The characteristic diagram of injecting oil and adjuster

Engine: 4D28
Model of injection pump: NJ
VE4/11F1900LNJ03
adjustment of injection pump

Adjustment Criterion
Rotating speed of Av. Discharge jet Range of
injection pump
mm3/stroke
unevenness
r/min

38.6

500

14.9

1000

42.1

1

Remarks

48
2

3

700

Av. discharge jet

(mm 3/st)

Fuel
temperature


50
2
50
2

4.0

1450

3

44.5

50
2

1800

47.6

3

60
2

2100

12.9
3

4.0

52
2

390

6.7
3

2.0

48
2

100

60
100

Standard

48
2

below

Adjustment Criterion
rotating speed of injection pump(r/min)

Sol
en
aut oid v
om alv
atic e o
adv f fue
anc l su
er O ppl
ff y

stroke of fuel supply

automatic advancer piston
(mm)

Sol
en
aut oid v
om alv
atic e o
adv f fue
anc l su
er O ppl
n y

adjustment of fuel supply automatic advancer

rotating speed of injection pump(r/min)

Rotating
speed of
injection
pump
r/min

700
1300
1600
1950

Stroke of fuel supply

automatic advancer piston
mm

Air pressure of
injection pump
(kPa)
Standard

Solenoid valve of fuel Solenoid valve of fuel

supply automatic
supply automatic
advancer
advancer
On
0.5
2

Off


1.4
0.1
3.9
2
7.0+0.1

0.3

On

Off




0.5
1

Standard

adjustment of speed control lever

Adjustment Criterion
Rotating speed
of injection Height
pump
m
r/min

1000
full speed

idle speed

Air pressure
difference
(kPa)

500

5.5
0.3

2000

21.9

Decreasing
amount
mm3/stroke

Decreasing rate
%

Expansion point Expansion point

4.6
1

11
3

FU-16

Fuel system-Maintenance and repair on the car

Fuel tank
Disassemble order
1. guard plate of fuel tank
2. cap fastener of tank filler
3. air hose of tank filler
4. hose of tank filler
5. oil drain block
6. fuel tank cushion
7. fuel sensor
8. tank cap
9. filter screen
10. fuel tank outlet hose
11. oil return hose of fuel tank
12. fuel tank outlet pipe
13. oil return pipe of fuel tank
14. three-lined oil pipe fastener
15. fuel tank

Assemble order
The assemble order is adverse to the
disassemble order.

Disassemble
Preparing work
Cut off the earth wire of battery.
1. Fuel tank plate
2. Cap fastener of tank filler
3. Air hose of tank filler
4. Hose of tank filler
5. Oil drain block
(a) Loosen the oil drain block and release the fuel.
(b) After releasing the fuel, tighten the block to set torque.
6.
7.

8.
9.
10.
11.
12.
13.

14.
15.

Tightening moment: 29N
m

Fuel tank cushion
Fuel sensor
Block the oil pipe joint after remove the pipe from the engine, which
can avoid leakage.
Tank cap
Filter screen
Fuel tank outlet hose
Oil return hose of fuel tank
Fuel tank outlet pipe
Oil return pipe of fuel tank
Block the oil pipe joint after remove the pipe from the engine, which
can avoid leakage.
Three-lined oil pipe fastener
Fuel tank

Fuel system-Maintenance and repair on the car

FU-17

Assemble
1.

Fuel tank
Notice:
When install the fuel tank onto the frame, pay attention to
set a cushion on the fuel tank of the frame.

2.

Three-lined oil pipe fastener

Tighten the fixing screws to set torque.
Tightening moment: 19N
m

3.
4.

Oil return pipe of fuel tank

Fuel tank outlet pipe
Connect the outlet pipe and return pipe with the engine and
fastened by fastener.

5.

Oil return hose of fuel tank

6.
7.

Fuel tank outlet hose

Filter screen

8.
9.

Tank cap
Fuel sensor
Connect the fuel sensor with the fuel gauge.

10. Fuel tank cushion

11. Oil drain block
12. Hose of tank filler
13. Cap fastener of tank filler
14. Air hose of tank filler
15. Fuel tank plate
(a) Tighten the fixing screws of the plate to set torque.
Tightening moment: 55N
m
(b) Fill fuel to the fuel tank.
(c) Connect the earth wire of battery.

FU-18

Fuel system-Maintenance and repair on the car

Fuel gauge
Disassemble order
1. fuel sensor
2. fuel level gauge

Assemble order
The assemble order is adverse to the disassemble order.

Disassemble
Preparing work
Cut off the earth wire of battery.
1.

Fuel sensor
Remove the fuel sensor from the fuel level gauge.

2.

Fuel gauge
Remove the fixing screws of fuel level gauge and the fuel
gauge.
Notice:
After the fuel level gauge is removed, block the fuel
tank inlet by cotton waste, which can guard the
impurities.

Assemble
1.

Fuel level gauge

Install the fuel level gauge on the fuel tank.

2.

Fuel sensor
Connect the fuel sensor with fuel level gauge.

FU-19

Fuel system-Throttle line

Throttle line
Control line of the throttle valve

Disassemble order
1. control line of the throttle valve
2. bolts
3. spring washer
4. flat washer
5. throttle line frame (front)
6. bolts
7. throttle line frame (back)

Assemble order
The assemble order is adverse to
the disassemble order.

Disassemble
1.

Control line of the throttle valve

Loosen the adjusting screws of the throttle bracket on the inlet
pipe and remove the Control line of the throttle valve.

2.
3.

Bolts
Spring washer

4.

Flat washer

5.
6.

Throttle line frame (front)

Bolts

7.

Throttle line frame (back)

Check
Check the following items. Change the control line if there is
abnormal condition.
(a) The control line should move flexibly.
(b) The control line can not bend or kink.
(c) The control line can not be damaged or corrupted.

Assemble
1.
2.
3.
4.
5.
6.
7.

Throttle line frame (back)

Bolts
Throttle line frame (front)
Flat washer
Spring washer
Bolts
Control line of the throttle valve
Connect the control line with the injector and tighten the
adjusting screws on bracket.

FU-20

Fuel system-Throttle line

Throttle pedal

Disassemble order
1. accelerator lever
2. bracket case
3. bracket of accelerator lever
4. torsion spring
5. cotter pin
6. throttle pedal

Assemble order
The assemble order is adverse to the
disassemble order.

Disassemble
1.

Accelerator lever
Remove the accelerator lever from the bracket.

2.

Bracket case

3.
4.

Bracket of accelerator lever

Torsion spring

5.
6.

Cotter pin
Throttle pedal
Loosen the fixing screws, and remove the throttle pedal from the
cab side.

Assemble
1. Throttle pedal
2. Cotter pine
3. Torsion spring
4. Bracket of the accelerator lever
5. Bracket case
6. Accelerator lever
Install the accelerator onto the bracket and fix it by cotter pins.

Fuel system-Throttle line

FU-21

The adjustment of down force of the throttle pedal

(a) When finishing each control line, push the throttle pedal
seat in order to press the pedal to end through full travel.
(b)

Adjust the catch bolts to leave the clearance 0-2mm

between the seat back and the catch bolt. Tighten the lock
screws to set torque.

Tightening moment: 7.4N
m

(c) Check the clearance of throttle pedal. The normal clearance above the pedal seat is 5-10cm.
(d) Press the pedal to the end and check if the engine speed
is the highest and stable.
(e)

In the pedal working range, check whether the throttle

pedal and injector lever can return their initial position
freely or not.

FU-22

Fuel system-Throttle line

Air filter

Disassemble order
P
Q

1. snorkel tube
2. air filter cover
3. air filter element
4. air filter case

Assemble order
The assemble order is adverse to the
disassemble order.

Disassemble
1.

Snorkel tube

2.
3.

Air filter cover

Air filter element

4.

Air filter case

Clean
(a) Clean the inside of air filter case.
(b) Clean the air filter cover.

Check and repair

Check whether the air filter element is non-light-tight and has
any little holes.

Cleaning measures
When the filter core is blocked by dust:
To blow off the dust in the filter core, use the compressed air
to blow the filter core from the innner part of it to the outer part.
The pressure of the compressed air:(392-490)kpa
Remark:
In order not to damage it, the filter core should not be
knocked when cleaning .

Fuel system-Throttle line

FU-23

Carbon deposition and dust blocking the filter element

(a) Prepare the diluted cleaning liquid which is original of
the Great Wall Company.
(b) Dunk the filter element in cleaning liquid for about 20
minutes.

(c) After taking out the filter element from cleaning liquid,
flush it carefully by water. The water pressure should not
exceed 274Kpa.

(d)

Dry the filter element where is good ventilated. It is

favorable to use a fan.
Notice:
Do not use compressed air or open fire to dry the
filter element, or the filter element may be damaged.
It is about two or three days to thoroughly dry the
filter element. Thus, it is better to prepare a spare
filter element.

Assemble
1.
2.

Air filter case

Air filter element

3.
4.

Air filter cover

Snorkel tube

CO-1

Cooling system
Page
General .......................................................................
On vehicle repair .........................................................
Single piece repair ......................................................
Thermostat ..................................................................
Radiator .......................................................................
Conveying belt adjustment ..........................................

CO-2
CO-4
CO-7
CO-9
CO-10
CO-11

CO

CO-2

Cooling system -General

General
thermostat
cylinder cover

overflow tank

engine oil cooler

radiator
cold startup device
fan

water pump
vehicle heater

fuel injction pump

The cooling system of type 4D28 diesel engine is of pressured

coolant forced circulating type. The system consists of water pump,
thermostat, fan, radiator and other parts. Coarse oil in the filter is
cooled by circulating coolant.

Water pump
Centrifugal blade type water pump, V -belt driven.

Thermostat
swing valve

Wax pill thermostat, original valve is equipped with swing

valvelet (swing valve).
Thermostat is equipped on thermostat body.

CO-3

Cooling system -General

Radiator
Tube-band radiator for type 4D28 diesel engine. A valve with
cover is equipped with thermostat body of cylinder cover to
increase the boiling point of coolant which will open when
the pressure reaches 88-118kPa.

mixing ratio(%)

Anti-freeze fluid

freezing point(
)

(a) Relation between mixing ratio and freezing point

The freezing point temperature of engine coolant changes
with the ratio of anti-freeze fluid in water. Right mixing
ratio can be determined according to the curve diagram.
(b)

mixing ratio calculation

anti-freeze fluid (L)
Mixing ratio Z
anti-freeze fluid (L) +water (L)
Attention:
Anti-freeze fluid+water=10L. Total capacity of
cooling system.

If the total capacity of cooling system is 10L, then:

specific weight
mixing ratio

Mixing ratio(
)

Anti-freeze fluid(L)

Water(L)

10

0.5

9.5

10

1.0

9.0

15

1.5

8.5

20

2.0

8.0

25

2.5

7.5

30

3.0

7.0

35

3.5

6.5

40

4.0

6.0

45

4.5

5.5

50

5.0

5.0

(c) Mixing ratio

Specific weight of coolant in engine cooling system at
0
to 50
can be measured with suction densitometer,
and then the mixing ratio of coolant can be looked up in

coolant temperature(
)

the curve diagram.

(d)

The coolant is high quality ethylene-ethylene glycol

(-35
) based anti-freeze fluid.

CO-4

Cooling system -On-vehicle repair

On-vehicle repair
Water pump

1
3

Disassembly procedure
2
4

1. air guide cover of cooling fan

2. cooling fan assembly
3. drive belt of power steering pump and
air-conditioned compressor
4. drive belt of alternating current
generator
5. crankshaft vibration damper pulley
6. timing gear house cover
7. water pump assembly

Assembly procedure

The assembly procedure is reverse of

disassembly procedure.

Disassembly
Preparation

Disconnect earthing cable of storage battery.

Drain coolant.
1. Air guide cover of cooling fan
Remove overflow tank and air guide cover of cooling fan.
2. Cooling fan assembly
Loose locknut and disassembly cooling fan assembly.

3.

Drive belt of power steering pump and

airconditioned compressor
Loose adjustment bolt of power steering pump and disassembly drive belt.

Cooling system -On-vehicle repair

lock bolt

4.

CO-5

Drive belt of alternating current generator

Loose bottom set point of alternating current generator and
lock bolt of adjusting plate, dismount drive belt.

5.

Crankshaft vibration damper pulley

6.

Timing gear house cover

7.

Water pump assembly

Dismount water pump assembly, remove O-ring.

Inspection
If heavy wear or damage is found in inspection, necessary
repair and replacement of parts shall be carried out. If any of
following problem occurs, the water pump assembly must be
replaced.
(1)

Crack on water pump body

(2)
(3)

Leakage of coolant from water seal

Drunkenness of ball bearing or abnormal noise

(4)

Crack or corrosion of water pump impeller

Cooling system -On-vehicle repair

CO-6

Assembly
1. Water pump assembly
(a) mount O-ring into O-ring groove of water pump body.
(b)

Assemble water pump, screw down set bolt of water

pump to prescribed torque: 20N
m

2. Timing gear house cover

Assemble gear house cover and screw down set bolt of gear
house cover to
prescribed torque: 19N
m
3. Assemble crankshaft vibration damper pulley and screw
down set bolt of pulley to
prescribed torque: 206N
m

4. Drive belt of alternating current generator

drive belt of power steering pump and airconditioned compressor

5. Drive belt of power steering pump and airconditioned compressor

(a) Examine if there is wear or damage of drive belt, replace it
when necessary.
Examine the rate of tension of drive belt, adjust it when
necessary.
(b) Exert force of 98N on the middle section of the belt, examine
deflection of each belt.

drive belt of alternating current

generator and fan

Standard deflection :( 8-12) mm

6. Fan assembly
Mount water pump pulley and fan assembly onto water pump
in turn, screw down lock nut to prescribed torque.
Screw down torque: 8N
m

7.

Air guide cover of cooling fan

(a) Assemble air guide cover of cooling fan and overflow
tank hose.
(b) Connect storage battery earthing cable.
(c) Fill in coolant.
(d)

Start engine and examine coolant leakage.

CO-7

Cooling system -Single piece repair

Single piece repair

Disassembly
Disassembly procedure
1. set screw
2. centre flange of fan
3. water pump impeller
4. water seal assembly
5. oil slinger
6. bearing assembly
7. water pump body

Reassembly procedure
The disassembly procedure is reverse
of assembly procedure.

Disassembly
1.

Set screw

2.

Centre flange of fan

Force down centre flange of fan using bench press and compression bar.

3.
4.

Water pump impeller

Water seal assembly

5.

Oil slinge

6.

Bearing assembly
(a) Heat up water pump body in hot water of 80 to 90

(b)

Force down water pump impeller, water seal assembly

and bearing assembly using bench press and compression bar.

Attention:
Do not try to dismount water pump impeller with
hammer, otherwise the impeller will be damaged.
7.

Water pump body

CO-8

Cooling system -Single piece repair

Inspection and maintenance

If heavy wear or damage is found in inspection, necessary
adjustment, repair and replacement of parts shall be carried out.
Bearing assembly
Inspect if there is any noise, stagnant and other abnormal condition.

Reassembly
1. Water pump body
2. Bearing assembly
(a) Force bearing assembly into water pump body.
(b) Align the bearing set screw hole to set screw hole of water
pump body.
(c) Fix bearing assembly with set screw.
3. Set screw
4. Oil slinger
5. Water seal assembly
(a) Apply a film of liquid sealant on the outer surface of water
seal assembly.
(b) Assemble water seal assembly.

6.

Water pump impeller

(a) Mount water pump impeller with bench press.
(b) Measure the distance between projection portion of water
pump impeller and end surface of water pump body.
The dimension (L) of projection portion on water pump
impeller must be ensured which shall be 24mm.
7. centre flange of fan
Measure the distance between fan fitting surface and back cover
fitting surface.
Standard value is 79.2 to 79.8mm.
Attention:

Mount centre flange of fan and impeller of water pump
onto water pump shaft with press machine. Do not
dismount and mount centre flange of the fan and impeller
of the water pump for the second time, otherwise, the
total water pump assembly shall be replaced. The water
pump will be damaged and overheated if centre flange of
the fan and impeller of the water pump have been
dismounted and mounted for the second time.

If the force applied on the centre flange of the fan and
water pump impeller is less than 1960N, the water pump
assembly must be replaced.

Do not knock the bearing into water pump body with
hammer and the like, or the bearing will be damaged.

CO-9

Cooling system -Thermostat

Thermostat

Disassembly procedure
1. socket joint part
2. thermostat top shell
3. thermostat gasket
4. thermostat

Assembly procedure
The assembly procedure is reverse of
disassembly procedure.

Disassembly
Preparation

1.
2.

3.
4.

Disconnect earthing cable of storage battery.

Drain coolant.
Socket joint part
Discharge tube
Dismount fixed bolt and remove
thermostat top shell and radiator hose.
Thermostat gasket
Thermostat

Inspection and maintenance

(a)

Immerse the thermostat assembly into noncorrosive

neutral fresh water.

(b) Place wood block on the bottom of the vessel. Do not

heat thermostat directly.
(c) Increase water temperature gradually and stir the water
to balance the water temperature in the vessel.

Confirm that the main valve opens at prescribed
temperature.
Valve open temperature is 82

Confirm that the secondary valve wide open at prescribed
temperature.
Valve wide open temperature is 95

If found thermostat heavy wear or damage, necessary
repair and replacement must be carried out.

Assembly
1.
2.
3.

Thermostat
Thermostat gasket
Thermostat top shell
Mount thermostat top shell and screw down the set bolt to
prescribed torque.
The screw down torque is 19N
m
4. Socket joint part

Connect the earthing cable of storage battery.

Fill in qualified coolant of prescribed quantity or to
prescribed indication mark.

Start engine and examine if there is any coolant leakage.

CO-10

Cooling system -Adjustment of drive belt

Radiator

Disassembly procedure
1. overflow tank hose
2. radiator hose
3. condenser
4. radiator assembly

Assembly procedure
The assembly procedure is reverse of
disassembly procedure.

Disassembly
Preparations

Disconnect earthing cable of the storage

battery.

Drain coolant.

1. Overflow tank hose

Remove overflow tank hose from the

Inspection and maintenance

1. Radiator cover
(a) Test response pressure of pressure valve with tester of
radiator cover.
Standard value of the response pressure is 88
to 118kPa.

radiator.
2. Radiator hose
Remove radiator top hose and bottom hose
from the engine.
3. Condenser

If the response pressure is larger than the standard

value, the radiator cover shall be replaced.
(b) Check the response pressure of vacuum valve in the
centre of radiator cover valve seat.
The standard value of the response pressure is

Remove condenser from the radiator and

put it aside.
4. Radiator assembly
Withdraw the radiator assembly upward
together with hose.
Pay attention not to scuff radiator core by
fan blades.

12.7 to17.0kPa.
If the vacuum valve can not move smoothly because of
corrosion or dust, the radiator cover shall be cleaned or
replaced.
2. Radiator core
(a)

thermolysis will be decreased when the radiator deformed and the cooling system will be overheated. Flat
the radiator fin and pay attention not to damage the root

(b)

of radiator fin.
Remove dust, dirt and other foreign material.

3. Flush the radiator

Flush the inner channels and coolant channels of the radiator
with water and neutral liquid detergent. Remove all scale
and deposit.

Cooling system -Adjustment of drive belt

CO-11

4. Examine coolant leakage

Press the compressed air of 196.9kPa from radiator filling hole
into the radiator with radiator cover tester. Examine if there is any
coolant leakage in the cooling system.

Assembly
1. Radiator assembly
Assemble the radiator assembly with hose. Pay attention not to
scuff the radiator core with the fan blades.
2. Condenser
Mount the condenser onto the radiator.
3. Radiator hose
(a) Connect the entrance hose of radiator and outlet hose with
the engine.
(b) Connect earthing cable of the storage battery.
(c) Fill in qualified coolant to the neck of radiator filling hole
and to the MAX mark of overflow tank.
4. Overflow tank hose
Start the engine and warm up. Examine the level of coolant.
drive belt of power steering pump and
air-conditioned compressor

drive belt of alternating current generator and fan

Adjustment of drive belt

Inspection and maintenance
(a)

Examine if there is any wear or damage of drive belt, replace

it when necessary.

(b)

Examine the rate of tension of drive belt, adjust it when

(c)

necessary.
Exert force of 98N on the middle section of the belt, examine

deflection of each belt.

Standard deflection: ( 8-12) mm

Adjustment of belt tension rate.

1. Belts of alternating current generator and fan pulleys
(a) Loose alternating current generator support lock bolt, adjust
belt tension rate with adjustment bolt on the adjustment
plate.
(b) Screw down set bolt to prescribed torque.
Screw down torque of generator set bolt is 25N
m
Screw down torque of adjustment plate set bolt is 19N
m
2. Power steering pump and air-conditioned compressor
pulley belts
Adjust belt tension rate with power steering pump adjusting bolt.
Screw down lock nut of adjustment bolt after adjustment.

ST-1

Starting system
Page
Summary ..................................................................... ST-2
Service on the vehicle ................................................. ST-4
Single piece maintenance ........................................... ST-5

ST

ST-2

Starting system- Summary

Summary
starting relay

starting motor

starting switch
holder winding
contact point

50
terminal connector

pinion shaft clutch

30
terminalconnector
electromagnetic
switch
suction
winding

storage battery

Starting system
Starting System is composed of storage battery, starting motor,
starting switch, ignition lock, starting relay and so on. These
components are connected as the diagram shown above, and it
also can be used as the detailed specification of the starting
circuit.

Starting motor
Starting system uses magnetic reduction motor; its bearing is
also used as pinion shaft. when starting switch being closed, the
magnetic switch contact point closes and causes the armature to
rotate, attracts movable core and the tappet trundles the pinion
shaft forward to mesh with ring gear at the same time ,then the
ring gear rotates to starts the engine. When the engine starts up
and the starting switch is unlocked, the movable core returns,
the pinion disengages from the ring gear and armature stops
rotating. The pinion runs without load while the speed of engine
is much higher than which of pinion, so the armature isnt being
driven.

ST-3

Starting system- Summary

Starting circuit

starting switch
storage battery

fuse

fuse
fuse

fuse
starting relay

quick start component

suction winding.

retaining coils
electromagnetic switch

starter

ST-4

Starting system-Service on the vehicle

Service on the vehicle

Starter
Disassembly procedure
1.

50
wiring terminal
2.

30
wiring terminal
3. earthing cable wire terminal
4. engine assembly
5. isolation board (cold area excluded)

Assembly procedure
Assemble according to the reverse procedure
of disassembly.

Disassembly
Preparations
Disconnecting the grounded cable of storage battery
1.
50
terminal post
2.
30
terminal post
3. Earth wire cable post
4.

Starting motor assembly

5.

Separation plates(Cold regions except)

Assembling
1.
2.

Separation plates(Cold regions except)

Starting motor assembly
Screw tight fixed bolts and nut to the provided torque

3.

Screwing torque: 81N.m

Earth wire cable post

Connect the grounded cable of storage battery

4.
50
terminal post
Connect wire connectors
5.
30
terminal post
Connect earth wire cable post of storage battery to the wire
Connector of the starting switch, then screw tight fixed nut to
the provided torque.
Screwing torque: 81N
m
Connect the grounded cable of storage battery

ST-5

Starting system-Single piece maintenance

Single piece maintenance

Discomposition sequence
1. lead wire
2. through bolt
3. yoke assembly
4. yoke cover
5. carbon brush and Carbon brush holder
6. armature
7. driving box
8. overriding clutch
9. return spring
10. steel ball
11. pinion
12. holder
13. roller
14. magnetic switch.

Reassembly sequence
Reassembly according to the reserve order
of discomposition.

Decomposition
1.

Lead wire
Remove the wire from the magnetic switch.

2.

Through bolt
Remove the through bolt from the yoke.

ST-6

Starting system-Single piece maintenance

3.

Yoke assembly
Separating the yoke from magnetic switch

4.

Yoke cover

5.

Carbon brush and Carbon brush holder

Disassemble the brush and the holder from armature with
shaft-mouth plier

carbon brush

6.

Armature

7.

Driving box

8.

Overriding clutch

spring

Disassemble the overriding clutch from the box.

9.

Return spring
Disassemble the return spring from the magnetic switch

10. Steel ball

Disassemble the steel ball from the overriding clutch

ST-7

Starting system-Single piece maintenance

11. Pinion
Disassemble the pinion from the box

12. Holder
Disassemble the holder from the box
13. Roller
14. Magnetic switch.

Checking and repairing

If find abrasion, destroyed or any other unusual conditions in
the checking, then need to repair or replace parts.

Armature
(a) Checking the quantity of radial runout of ring header, if
it exceeds the provide limit, and then need to replace the
ring header.
Quantity of radial runout

insulator

ring header

mm

Output(kw)

Standard

Limit

2.8

0.02

0.05

(b) Check the mica is worn or not.

Depth of mica

mm

Output(kw)

Standard

Limit

2.8

0.70-0.90

0.20

accurate

inaccurate

(c) Check the outer diameter of ring header.

Outer diameter of ring header
Output(kw)

Standard

Limit

2.8

35.00

34.00

mm

ST-8

Starting system-Single piece maintenance

Armature short-circuited test
Put the armature in the short-circuited test meter to check if it
is short-circuited.
When rotate the armature slowly, make the saw blade touch the
armature core ,short-circuited armature makes the saw blade
oscillating and attracted by core .if so , it indicates that
armature has been short-circuited ,must be replaced.

Armature earth connection test

Connect one probe of the multimeter to the ring header; the
other to the armature core, the result will turn to be opencircuited. If closed-circuited, it means that armature has connected to earth. Replace the armature.

Armature closed test

Connect both of the multimeters probes to the ring header
it must be closed-circuited on any test point .open-circuited,
replace the armature.

Yoke
Magnetic winding earth connection test
Connect one probe of the multimeter to the magnetic winding
connector or brush, the other to the outside surface of the yoke.
The result will turn to be open-circuited .if the multimeter
shows closed, it means the magnetic winding has connected to
earth, replace the unit yoke.

Magnetic winding closed-circuited test

Connect one probe of multimeter to the terminal connector

C

, the other to the brush; the result will turn to be closedcircuited. If open-circuited, then replace unit yoke.

ST-9

Starting system-Single piece maintenance

Carbon brush and carbon brush holder

Measure the length of the carbon brush, if the abrasion
exceeds the using limit, then the carbon brush should be
replaced.
Length of carbon brush

mm

Output(kw)

Standard

Limit

2.8

14.5

10

Insulation experiment of the carbon brush holder

Check the carbon brush holder is insulated with the Multimeter.
Put one of the probe on the board of the brush holder, the other
touches the positive of the brush holder.
The result will turn to be open-circuited.

Overriding clutch
Check the tooth of the pinion is worn or destroyed, if destroyed,
then new one instead. When make the pinion rotating clockwise, it should be rotating freely. If anticlockwise, the pinion
will be locked up.

Bearing
Check the bearing is worn or destroyed, if noise is produced
when the bearing is in operation, the bearing will be replaced.

Reassembling
Reassembling sequence is inverse the sequence of
decomposition. Notice the following:
steel ball

Magnetic switch

Idle gear

Clutch assembly

roller
idle gear

Box

a
Unit clutch is fitted on the magnetic switch.

b
Fix gear and box.

ST-10

Starting system-Single piece maintenance

Note:
Do not forget to mount the ball and spring between clutch
and magnetic switch. Before this, mount the roller on the
pinion.

Magnetic switch
Link the magnetic switch between clutch and box temporarily
then do the following experiments. Each experiment must be
completed in 3 to 5 seconds.
M terminal connector

1.

Combine force of pull and push test

Connect the negative terminal connector of storage battery to
shell and M .When the current runs from positive of the story
battery to the terminal connector 50, pinion will shift.

50
terminal connector

disconnect

2.

Holding test
Cut off the wire of M ,the pinion keeps shifting.

PK Return test
Connect the negative terminal connector of the storage battery
to terminal connector 50 and shell, the positive terminal
connector of the storage battery to M, the pinion will be
wobbling. When cut off the wire which is connected to
50

,
the pinion returns to the position before its shifting immediately.

QK Current

30
terminal connector

As the figure shows, Connect the positive pole of the storage

battery to the amperometers positive pole, the negative pole
to the body, amperometers negative pole to the terminal
connectors of 30 and 50.then measure the value of current.
Standard value will be 120A or less.
Note:
The storage battery must be full-charged. Wide wire
should be used, because big current will go through it.
terminal connector

CH-1

Charging appliance
Page
General .......................................................................
Diagnosis ....................................................................
On-vehicle maintenace ...............................................
Single piece maintenance ...........................................

CH-2
CH-4
CH-5
CH-8

CH

CH-2

Charging appliance-General

General
Electric generator
14V-50A
fan
rotor
carbon brush
stator
Integrated circuit(IC) adjuster
rolling bearing
rolling bearing
oil seal

vacuum pump

pulley

front cover

through bolt
slide
ring

back cover

The charging appliance is of integrated circuit (IC) universe

adjuster type. Main parts shall be connected according to the line
diagram shown in the figure.The adjuster is not a solid circuit. It
is assembled together with carbon brush bracket in the motor and
assembled on the back end cover.
The electric generator need no special maintenance as voltage adjuster.there are nine diodes in the rectifier connected with
the stator coils in order to convert AC voltage to DCThe DC
voltage will be rectified and then be fed to the output terminals of
electric generator.

CH-3

Charging appliance-General

Charging circuit

startup switch

storage battery

fuse

fuse

oil seal

fuse

generator

speed indicator
of the generator

S
wiring terminal

W
wiring terminal

L
w i r i n g
terminal

I G
w i r i n g
terminal

charging relay

to charging alarm light

to charging signal

CH-4

Charging appliance-Diagnosis

Diagnosis

resistance

storage battery

resistance
kindle switch

charging alarm light

S
wiring terminal

W
wiring terminal

generator

speed indicator
of the generator

charging relay

L
wiring terminal

IG
wiring terminal

On-vehicle comprehensive inspection

The operating condition of the charging appliance is indicated
with the charging alarm light.when the starting switch is turned to
close position, the alarm light will be on.when the engine starts, the
charging system operates properly if the alarm light off.If the alarm
light shows abnormal or you doubt about insufficient or excess
charging of battery, the following inspection shall be carried out for
the charging system.
1. Visual examination of belt and lead socket joint.
2. When the engine is stop, turn the starting switch to
close

position and examine the state of alarm light.

If the alarm light is not on
Disconnect the lead socket joint from the engine, and earth
The
L
terminals on the socket joint.

If the alarm light is on

Repair or replace the electric generator.

CH-5

Charging appliance-On vihicle maintenance

On vihicle maintenance

Disassembly procedure

T
lock nut

1. power steering pump and air

conditioning compressor
2. air conditioning compressor assembly
3. lead socket joint
4. vacuum hose
5. engine oil hose
6. driving belt of AC electric generator
7. power steering pump assembly
8. assemble according to the reverse
procedure of disassembly
9. AC electric generator assembly

Assembly procedure
Fastening bolts of AC generator

Disassembly
Preparation
1.

Disconnect the earthing cable of storage battery.

belts of power steering pump and air conditioning
compressor
Loose the bolts of power steering pump belt and dismount
the driving belt.

2.

air conditioning compressor assembly

(a) Disconnect lead socket joint of the clutch.
(b)

3.

Dismount the bolts of air conditioning compressor,Remove the air conditioning compressor assembly.

Lead socket joint

(a) Disconnect the terminals L, S, W and IG.
(b) Disconnect the terminal B.

4.

Vacuum hose
Remove the vacuum hose from the vacuum pump of the
electric generator.

5.

Engine oil hose

remove the engine oil hose
from the bottom case.
remove the engine oil hose
from the body.

CH-6

Charging appliance-On vihicle maintenance

6.

Driving belt of AC electric generato

(a) Loose the fastening bolts of adjusting plate.
(b) Dismount adjusting bolts.
(c) Loose the fastening bolts of AC electric generator and
dismount the driving belt.

7.

Power steering pump assembly

(a) Loose the adjusting bolts and dismount the driving belt.
(b) Dismount the bolts of power steering pump, remove the

UK

power steering pump assembly.

Fastening bolts of AC generator

VK

AC electric generator assembly

Disassemble the AC electric generator assembly from the
engine.

Assembly
1.

AC electric generator assembly

Installation of AC electric generator assembly

2.

fastening bolts of AC generator

Temporarily mount fastening bolts of AC generator

3.

Power steering pump assembly

(a) Mount the power steering pump assembly and screw
down the fastening bolts to prescribed torque.
Tighten torque: 19N
m
(b) Connect the feed and return oil hose of the power steering
pump and fasten them with clips.

belts of air conditioning compressor and

power steering pump

Driving belt of AC electric generator

Mount the driving belt of AC generator and adjust its tensity.
Press the middle of the driving belt with 98N force.
Driving belt deflection: (8-12)mm.
Mount the fastening bolts and screw down to prescribed torque.
Screw down torque of electric generator fastening
bolt is: 25N
m

belts of air conditioning compressor and power

steering pump

Screw down torque of adjusting plate fastening bolt

is: 19N
m

Charging appliance-On vihicle maintenance

5.

CH-7

Engine oil hose

(a) Mount the engine oil hose
onto the bottom case.
(b) Mount the engine oil hose
onto the body

engine oil hose

engine oil hose

6.

Vacuum hose
Mount the vacuum hose to the vacuum pump of the electric
generator.

7.

Lead socket joint

Connect the terminals
L
,
S
,
W
,
IG
and
B
.

8.

Air conditioning compressor assembly

(a)

Mount the air conditioning compressor assembly and

screw down the fastening bolts to prescribed torque.
Tighten torque: 19N
m

(b) Connect lead socket joint of the magnetic switch.

belts of air conditioning compressor and power

steering pump

9.

Belts of power steering pump and air conditioning

compressor
(a) Mount the driving belt and adjust its tensity.
(b) Press the middle of the driving belt with 98N force.
Driving belt deflection: (8-12)mm.
(c) Connect the ground cable of storage battery.

driving belt of AC electric generator and fan

CH-8

Charging appliance-Single piece maintenance

Single piece maintenance

Disassembly procedure
1. vacuum pump
2. lead
3. through bolt
4. rotor and front cover assembly
5. stator and back cover assembly
6. rotor
7. back bearing
8. terminal bolts and nuts
9. back cover
10. stator
11. diode
12. integrated circuit (IC) adjuster
13. carbon brush bracket

Reassembly procedure
Reassemble according to the reverse
procedure of disassembly.

Disassembly
1. Vacuum pump

seal protective cover

(a)

Drain liquid from the exit.

(b)

Dismount the fastening bolts of vacuum pump.

Hold center plate and disassembly the vacuum pump
horizontally along the rotor axis.
single piece maintenance disassembly

2. Lead
3. Through bolt
4. Rotor and front cover assembly
5. Stator and back cover assembly
Insert the screwdriver into the space between the front cover
and stator core, dismount the assembly.
Attention:
Pay attention not to damage the stator core when using
screwdriver.
When the assembly can not be dismounted, fasten the
back cover and slowly knock the axis end face with
plastic hammer.

CH-9

Charging appliance-Single piece maintenance

6.

Rotor
Grip the rotor with nip, dismount belt nut
, remove the pulley

, fan
, front cover
and the rotor
.

7.
8.

Back bearing
Terminal bolts and nuts

9.

Back cover
(a) Dismount the nuts fastening B terminal and diode.
(b) Separate stator and back cover.Pay attention to the location of insulating spacer so that they can be mounted to
their original location when reassembly.

10. Stator

11. Diode
Melt and remove the solder on stator core and diode, dismount
the diode from the stator.Grip the leads when melting the
solder to prevent heat from transferring to the diode.

terminal bolts
rivet

12. Integrated circuit (IC) adjuster

diode
terminal plate

melt the solder on the support bracket of IC adjuster, separate

the IC adjuster and diode, then remove the nuts.

13. Carbon brush bracket

(a) Dismount fine-pitch screw and melt solder on the IC
adjuster.
(b) Fine-pitch screws shall be dismounted only when replacing carbon brush or capacitance, otherwise, do not dismount fine-pitch screws.
(c) Aassemble according to the reverse procedure of
wear limit

disassembly.

Inspection and maintenance

Parts must be repaired or replaced when excess wear or
damage is found in examination.
Rotor
(a) Examine if there is any pollution or roughness on the
rotor slide ring surface.Polish the rough part (if any) with
500# to 600# sand paper.
(b) Measure the diameter of slide ring, replace it if the
diameter surpasses limit.
mm
Standarrd
34.6

limit
33.6

CH-10

Charging appliance-Single piece maintenance

multimeter

`eJNM

(c) Examine if the circuit between the slide rings is closed,

replace them if circuit is open.

slide ring

multimeter

(d)

Examine if the circuit between the slide ring and rotor

iron core or rotor axis is closed.
If the circuit is closed, replace the rotor assembly.

slide ring

retaining ring
ball bearing
multiple keys

Back rolling bearing

(a) Examine if the rolling bearing can run properly without
nois.When the rolling bearing can not run properly or
noise can be heard, the rolling bearing must be replaced
with a new one.
(b)

When mount the bearing, snap ring must be pressed in

together with the bearing. The snap ring shall face the
spline end.
The press-in distance of the bearing is 41.8 to 42.0mm

multimeter
lead

Stator core
(a) Examine if the circuit between every phase is closed.If
the circuit is open, replace the stator.

multimeter
lead

(b) Examine if the circuit between stator winding and stator

iron core is closed.The winding shall be replaced when
the circuit is closed.

CH-11

Charging appliance-Single piece maintenance

Diode

multimeter

(a) Examine if the circuit between terminals (for example:

BAT and U) is closed.If the circuit is closed, that means
the diode is ok; if the circuit is open, that means the diode
is unqualified.
(b) Ttest with reverse polarity.if the circuit is closed in every
point, it means the diode is unqualified and shall be
replaced.Auxiliary diode has no terminals, so circuit test
always is carried out between the two ends of the diode.
Examination of diode negative end

U,V and W indicate wiring terminals of stator windings.

negative end of
the diode

Connecting terminal
The probe of
themuitimeter
U.V.W
positive end
Negative

The positive end of the diode

Postive end
Neggative end
Open circuit
Close circuit

auxiliary diode
storage battery

current direction

Examination of diode negative end

Connecting terminal
The probe of
the muitimeter
U.V.W
positive end
Negative

The negative end of the diode

Postive end
Neggative end
Open circuit
Close circuit

Carbion brush
Measure the longth of the carbon brush.
Longth of the carbon brush

L

Standard
20

mm
Limit
16

The horizontal line on the carbon brush indicates its usage

limit.
wear limit

Ingegrate circuit adjuster

Needs measurement appliances
Connect the instrument appliances as shown in the diagram
and carried out the following measurements.
V
V1 is the voltage on BAT1
zero
point

Standard

10-13

V 2is the voltage on F-E

storage battery (12*2)

Standard

2

Disconnect the terminal
S
to measure.

V
Limit

2

CH-12

Charging appliance-Single piece maintenance

The adjuster shall be replaced if the voltage breaks in any point.

V3is the votage on BAT1-BAT2

Standard

20-26

V4 is the voltage between middle tap of variable resistor and

terminal
E
when the resistance value of the resistor not
changed.

Storage battery (12V*2) V3 is the voltage

between BAT1 and BAT2. Measure the voltage when gradually changes the resistance
value from zero with the variable resistor.
voltage between E and Fand then examine if

standard votage at 20

14.0-14.9

The adjuster shall be replaced when the measuring value deviates

from standard value.
(b) Connect the instrument appliances as shown in the diagram

the voltage increases from 2V to 10 to 13V.

and examine the following items.

Measure the voltage between terminals B and E with the
variable resistor gradually increasing voltage.Examine if
the voltage increases from 2V to 10 to 13V.If the voltage
does not change, it means the adjuster is unqualified and

zero position

shall be replaced.
Measure the voltage between middle tap of variable resistor
and terminal
E
when the resistance value of the resistor
not changed.
standard votage at 20

storage battery
12*2

14.0-14.9

The adjuster shall be replaced when the measuring value deviates

from standard value.

Vacuum pump
blades

Visual examination

centre plate

Examine if there is any wear, damage or other abnormal condition on the vacuum case, blades and check valves.
Vacuum pump disassembly
Center plate, rotor and blades disassembly is mentioned here.
rotor

case

Case
Measure the inner diameter, the case shall be replaced when the
measuring value surpasses standard value.
case inner diameter () is 57.0 to 57.1mm.
Blades
Measure the length of blades.
length of the blade (L) is 41.8 to 42mm.
Inspection of check valve
end A

end B

push
compressed air

(a)

Press B end of the check valve with screwdriver and

examine if the valve can operate properly.

(b)

Lead compressed air of 98 to 490 kPa into
A
end of the

check valve and examine if there is any leakage in the check
valve.

Charging appliance-Single piece maintenance

CH-13

Vacuum pump reassembly

(a) Position the stator on the center plate and the case when
the fine-pitch spline upward.Align the holes of center
plate and the rotor.
(b)

Mount the blade into the slots of rotor.Blade chamfer

shall face outward when assembly.

(c) Mount O-ring and center plate.

chamber end

Reassembly
1.

Carbon brush bracket assembly

2.

Integrated circuit (IC) adjuster assembly

(a) Catch hold of the carbon brush with carbon brush bracket
(b)

as shown in the diagram and weld the leads.

Put the IC adjuster onto the carbon brush bracket and
press into bolts.Insulating pipes and joint plate must be
assembled when pressing into bolts.

joint plate

3.

Diode
Connect the terminals in the position
with fastening rivets
and weld the terminals in the position
.

4.

Stator
When welding the stator winding and diode leads, bite the
diode lead with nipper pliers and finish the job as soon as
possible to prevent heat from transferring to the diode.

5.

Back cover

6.

Terminal bolts and nuts

7.

Back bearing

CH-14

Charging appliance-Single piece maintenance

UK

Rotor
Wrap nip jaw, clamp the rotor with the nip and screw down
pulley nuts to prescribed torque.
Tighten torque: 90N
m

9.

Stator and back cover assembly

10. Rotor and front cover assembly

11. Through bolt

(a) Pull he guide bar through front cover and back cover
flanges for alignment, and then mount through bolts.
(b)

Screw down the through bolts to prescribed torque.

Tighten torque: 35N
m

12. Lead

13. Vacuum pump

(a) Mount the case onto the electric generator with three
bolts.
(b)

Screw down the fastening bolts of vacuum pump to

prescribed torque.

Tighten torque: 35N
m

(c) Fill engine oil through oiling port (about 5ml), and then
examine if the electric generator pulley can run properly.
brand of the engine oil: Grade CD, GB11122-1997
diesel oil engine oil

EX-1

Exhaust system
Page
General ....................................................................... EX-2
On-vehicle repair ......................................................... EX-3
Front exhaust pipe ...................................................... EX-4

EX

EX-2

Exhaust system-General

General
Attention:
There must be sufficient distance between exhaust system
assembly and car body bottom board to prevent bottom
board from overheat and damage to passenger carriage
insulation and decorating material.

When examine or replace exhaust system assembly, sufficient

distance between exhaust system and any part of car body bottom
board must be ensured to prevent bottom board from overheat and
damage to passenger carriage insulation and decorating material.
Examine if there is any crack, damage, part loss or misplacement
in the whole exhaust system, nearby car body surface and back car
body cap. Examine if there is any joint disconnection or eyelet, any
loose connection or any other damage which may cause exhaust fume
leak into back car body or passenger car body. It means so if there is
any dust or water in the back car body. Any fault must be eliminated.

Exhaust system-On-vehicle repair

EX-3

On-vehicle repair
Detonation and vibration noise of exhaust system normally are caused
by parts misalignment. When adjust the system, unlock all of the bolts and
nuts first until all of the parts properly aligned, then tightening all of the
bolts and nuts from front to end.
Examination contents:
1. Examine if there is any loosening or damage of joint, especially
exhaust fume leakage.
2. Examine if there is any defect, crack or damage of clamp plate and
rubber.
3. If any part of catalyzed converter heat shield damaged or if there
is any drop pit spreads to the location of catalyzer, it shall be
repaired or replace
4.

Examine if there is any drop pit, damage or any eyelet, crack

caused by corrosion.

EX-4

Exhaust system-Front exhaust pipe

Front exhaust pipe

Disassembly procedure
1. tightening nut of front exhaust pipe
2. set bolt of front exhaust pipe installation support
3. set bolt and tightening nut of front exhaust pipe
4. front exhaust pipe
5. elbow pipe

3
4

Assembly procedure
Assembly procedure is inverse of disassembly
procedure.

Disassembly
Preparations
Disconnect ground cable of the storage battery.
1. Tightening nut of front exhaust pipe
dismount the two tightening nut from the joint of exhaust manifold
and front exhaust pipe.
2. Set bolt of front exhaust pipe installation support
3. Set bolt and tightening nut of front exhaust pipe
Dismount the two set bolts and tightening nuts from the joint of front
exhaust pipe and centre pipe.
4. Front exhaust pipe
Dismount front exhaust pipe and put it aside.
5. Elbow pipe

Assembly
1. Elbow pipe
2. Front exhaust pipe
Mount front exhaust pipe onto exhaust manifold.
3. Set bolt and tightening nut of front exhaust pipe
Tightening set bolts and tightening nuts of front exhaust pipe to
specific torque.
4. Set bolt of front exhaust pipe installation support
Tightening set bolt of support to specific torque.
Tightening torque is 40N
m
5. Tightening nuts of front exhaust pipe
(a) Tightening fixed nuts of front exhaust pipe to specific torque.
Screw torque is 67N
m
(b) Connect ground cable of the battery.
(c) Start engine and examine if there is any joint leakage after all
parts have been assembled and found in order and no loss.