Isuzu NHR 4J Series, NPR 4J Series, NKR 4J Series Workshop Manual

WORKSHOP MANUAL

NHR • NKR • NPR

ENGINE

4J SERIES

SECTION 6

MEMO

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

NOTICE

Before using this Workshop Manual to assist you in performing vehicle service and maintenance operations, it is reco mmended that you carefully read and thoroughly understand the information contained in Section 0A under the headings “GENERAL REPAIR INSTRUCTIONS” and “HOW TO USE THIS MANUAL”.

All material contained in this Manual is based on the latest product information available at the time of publication. All rights are reserved to make changes at any time without prior notice.

Applicable Model : NHR55. NKR55. NPR55. NPR69

This manual is applicable to 1994 year model and later vehicles

.

THIS MANUAL INCLUDES THE FOLLOWING SECTIONS:

SECTION NO. CONTENTS

00 Service Information

6A Engine Mechanical

6A1 4JB1/4JB1T/4JB1-TC/4JG2 Engine

6B Engine Cooling 6C Fuel System 6D Engine Electrical 6E Exhaust Gas Reci rculation (EGR) System 6F Exhaust 6G Turbocharger

SERVICE INFORMATION 00 – 1

HOME

SECTION 00

SERVICE INFORMATION

CONTENTS

PAGE

Troubleshooting .............................................................................................................. 00 -2

Main Data and Specifications......................................................................................... 00 -30

Service Standard ............................................................................................................. 00 -34

Servicing........................................................................................................................... 00 -38

Fixing Torque...................................................................................................................00 -51

Special Tools.................................................................................................................... 00 -60

00 – 2 SERVICE INFORMATION

TROUBLESHOOTING

CONTENTS

PAGE

Hard Starting.................................................................................................................... 00 - 3

Starter Inoperative....................................................................................................... 00 - 3

Starter Motor Operates but Engine Does Not Turn Over......................................... 00 - 3

Engine Turns Over but Does Not Start...................................................................... 00 - 4

Quick-on Start System................................................................................................ 00 - 5

Unstable Idling.................................................................................................................00 - 6

Insufficient Power............................................................................................................ 00 - 7

Excessive Fuel Consumption......................................................................................... 00 - 9

Excessive Oil Consumption............................................................................................ 00 - 9

Overheating...................................................................................................................... 00 - 10

White Exhaust Smoke..................................................................................................... 00 - 10

Dark Exhaust Smoke....................................................................................................... 00 -11

Oil Pressure Does Not Rise............................................................................................ 00 - 11

Abnormal Engine Noise .................................................................................................. 00 -12

Engine Knocking......................................................................................................... 00 - 12

Gas Leakage Noise...................................................................................................... 00 -12

Continuous Noise........................................................................................................ 00 - 12

Slapping Noise............................................................................................................. 00 -13

Engine Cooling Trouble .................................................................................................. 00 -14

Engine Electrical Part Trouble........................................................................................ 00 - 15

Turbocharger ................................................................................................................... 00 -20

Lubrication Chart............................................................................................................. 00 - 29

SERVICE INFORMATION 00 – 3

1.HARD STARTING

1. STARTER INOPERATIVE Checkpoint Possible cause Correction

Battery

Fusible link Fusible link shorted Replace the fusible link

Starter switch Defective starter switch or starter relay Replace the starter switch or the

Loose battery cable terminal poor connections due to rusting

Battery discharged or weak Recharge or replace the battery

Fan belt loose or broken Adjust or replace the fan belt

Defective magnetic switch or starter relay Repair or replace the magnetic switchStarter motor

Defective starter motor Repair or replace the starter motor

Clean and/or retighten the battery cable terminal

Starter relay

2. STARTER MOTOR OPERATES BUT ENGINE DOES NOT TURN OVER

Battery

Loose battery cable terminal Clean and/or retighten the battery

cable terminal

Poor connections due to rusting Recharge or replace the battery

Battery discharged or weak Recharge or replace the battery

Fan belt loose or broken Adjust or replace the fan belt

Starter

Engine Piston, crank bearing seizure, or other

Defective pinion gear Replace the pinion gear

Defective magnetic switch Repair or replace the magnetic switch

Brush wear, Weak brush spring Replace the brush and/or the brush

damage

spring

Repair or replace the related parts

00 – 4 SERVICE INFORMATION

3. ENGINE TURNS OVER BUT DOES NOT START Checkpoint Possible cause Correction

Engine stop mechanism

Defective fuel cut solenoid valve Replace the fuel cut solenoid valve

FUEL IS NOT BEING DELIVERED TO THE INJECTION PUMP

Fuel Fuel tank is empty Fill the fuel tank

Fuel piping Clogged or damaged fuel lines. Loose fuel

line connection

Fuel filter

Fuel system Air in the fuel system Bleed the air from the fuel system

Fuel feed pump Defective feed pump Repair or replace the feed pump

Fuel filter overflow valve does not close Repair or replace the fuel filter

Clogged fuel filter element Replace the fuel filter element or the

Repair or replace the fuel lines Retighten the fuel line connection

overflow valve

filter cartridge

FUEL IS BEING DELIVERED TO THE INJECTION PUMP

Fuel

Use of the wrong fuel Use the correct fuel

Water particles in the fuel Change the fuel

Fuel system

Injection pump

Air in the injection pump Bleed the air from the fuel system

Injection nozzle stickingInjection nozzle

Injection nozzle injection starting pressure too low Improper spray condition

Defective fuel injection nozzle resulting in the fuel drippage after fuel injection

Defective injection pump control rack operation

Injection pump plunger worn or stuck Replace the injection pump plunger

Injection pump drive shaft seizure or other damage

Injection pump governor spring seizure Replace the injection pump governor

Adjust or replace the injection nozzle

Replace the delivery valve

Repair or replace the injection pump control rack

assembly

Replace the injection drive shaft

spring

SERVICE INFORMATION 00 – 5

4. QUICK-ON START SYSTEM

PREPARATION 1 Disconnect the thermoswitch connector.

2. Determine whether or not the glow plugs are receiving power. a) Make sure that the starter switch is “OFF”. b) Connect a voltmeter between one of the glow plugs and the cylinder wall. c) Move the starter switch to the “ON” position.

The voltmeter needle will show the souse voltage (12V) if the glow plugs are receiving power. If the voltmeter needle does not move, the glow plugs are not receiving power.

3. Perform the troubleshooting procedure.

GLOW PLUGS ARE RECEIVING POWER

Checkpoint Possible cause Correction

Glow plug indicator light does not turn on

Quick-on start timer Defective quick-on start timer Replace the quick-on start timer

Glow plug indicator light turns on the 0.3 seconds

Glow plug indicator light turns on for 3.5 seconds

Thermoswitch Defective thermoswitch Replace the thermoswitch

Glow plug continuity No glow plug continuity Replace the glow plugs

Defective indicator light bulb Replace the indicator light bulb

Defective quick-on start timer Replace the quick-on start timer

Return the starter switch to the “ON” position from the “START” position after the engine starts if the glow plug relay remains on less than 14 seconds, the quick-on start timer is defective

Move the starter switch from the “OFF” position to the “ON” position if the glow plug relay remains on less than 14 seconds, the quick-on start timer is defective

Replace the quick-on start timer

GLOW PLUGS ARE NOT RECEIVING POWER

Glow plug indicator light does not turn on

Quick-on start timer Defective quick-on start timer Replace the quick-on start timer

Broken indicator light fuse Replace the fuse

00 – 6 SERVICE INFORMATION

GLOW PLUGS ARE NOT RECEIVING POWER (Cont’d)

Checkpoint Possible cause Correction

Glow plug indicator light turns on for 3.5 seconds

Defective glow plug relay The glow plug relay does not turn on after the starter switch is moved from the “OFF” position to the “ON” position

Defective quick-on start timer Replace the quick-on start timer

Defective glow plug relay wiring harness Repair or replace the wiring harness

Defective fusible link or wiring harness The glow plug relay turns on when the starter switch is moved from the “OFF” position to the “ON” position

Replace the glow plug relay

Replace the fusible link or the wiring harness

2. UNSTABLE IDLING

Checkpoint Possible cause Correction

Idling system Idling improperly adjusted Adjust the idling

Fast idling speed Defective fast idling speed control device Repair or replace the fast idling speed

control device

Accelerator control system

Accelerator control system improperly adjusted

Adjust the accelerator control system

Fuel system

Fuel filter Clogged fuel filter element Replace the fuel filter element or the

Fuel feed pump Defective fuel feed pump Repair or replace the fuel feed pump

Injection pump Defective delivery valve resulting in fuel

Fuel system leakage or blockage Repair or replace the fuel system

Air in the fuel system Bleed the air from the fuel system

Water particles in the fuel system Change the fuel

fuel filter cartridge

Injection nozzle sticking Replace the injection nozzleInjection nozzle

Injection nozzle injection starting pressure too low Improper spray condition

drippage after fuel injection

Adjust or replace the injection nozzle

Replace the delivery valve

SERVICE INFORMATION 00 – 7

Checkpoint Possible cause Correction

Injection pump (Cont’d)

Valve clearance Valve clearance improperly adjusted Adjust the valve clearance

Compression pressure Blown out cylinder head gasket. Worn

Injection timing improperly adjusted Adjust the injection timing

Insufficient injection volume Adjust the injection volume

Defective idle spring Replace the idle spring

Defective governor lever operation Repair or replace the governor lever

Regulator valve improperly adjustment Adjust or replace the regulator valve

Broken plunger spring Replace the plunger spring

Worn plunger Replace the plunger assembly

Worn cam disc Replace the cam disc

Replace the related parts cylinder liner. Piston ring sticking

3. INSUFFICIENT POWER

Checkpoint Possible cause Correction

Air cleaner Clogged air cleaner element Clean or replace the air cleaner

element

Fuel Water particle in the fuel Replace fuel

Fuel filter Clogged fuel filter element Replace the fuel filter element or the

fuel filter cartridge

Fuel feed pump Defective fuel feed pump Repair or replace the fuel feed pump

Injection nozzle sticking Replace the injection nozzleInjection nozzle

Injection nozzle injection starting pressure too low Improper spray condition

Fuel injection pipes Fuel injection pipes damaged or obstructed Replace the fuel injection pipes

Adjust or replace the injection nozzle

00 – 8 SERVICE INFORMATION

Checkpoint Possible cause Correction

Injection pump

Compression pressure Blown out cylinder head gasket. Worn

Valve clearance Valve clearance improperly adjusted Adjust the valve clearance

Valve spring Valve spring weak or broken Replace the valve spring

Defective regulating valve Repair or replace the regulating valve

Defective delivery valve Replace the delivery valve

Defective timer Repair or replace the timer

Worn cam disc Replace the cam disc

Improper control lever operation Adjust or replace the control lever

Defective injection timing Adjust the injection timing

Repair or replace the injection pump

timer

Weak governor spring Replace the governor spring

Worn plunger Replace the plunger assembly

Replace the related parts cylinder liner. Piston ring sticking

Exhaust system Exhaust pipe clogged Clean the exhaust pipe

Full load adjusting screw seal

Open and improperly set adjusting screw seal

Adjust and reseal the adjusting screw

SERVICE INFORMATION 00 – 9

4. EXCESSIVE FUEL CONSUMPTION

Checkpoint Possible cause Correction

Fuel system Fuel leakage Repair or replace the fuel system

related parts

Air cleaner Clogged air cleaner element Clean or replace the air cleaner

element

Idling speed Poorly adjusted idling speed Adjust the idling speed

Injection nozzle Injection nozzle injection starting pressure

too low Improper spray condition

Fuel injection timing Fuel injection timing improperly Adjust the fuel injection timing

Injection pump Defective Delivery valve resulting is fuel

drippage after fuel injection

Valve clearance Valve clearance improperly adjusted Adjust the valve clearance

Compression pressure Blown out cylinder head gasket. Worn

cylinder liner. Piston ring sticking

Valve spring Valve spring weak or broken Replace the valve spring

Adjust or replace the injection nozzle

Replace the delivery valve

Replace the related parts

5. EXCESSIVE OIL CONSUMPTION

Checkpoint Possible cause Correction

Engine oil Engine oil unsuitable

Too much engine oil

Replace the engine oil

Correct the engine oil level

Oil seal and gasket Oil leakage from the oil seal and/or the

gasket

Air breather Clogged air breather Clean the air breather

Intake and exhaust valve

Worn valve stems and valve guides Replace the intake and exhaust

Replace the oil seal and/or the gasket

valves and the valve guides

00 – 10 SERVICE INFORMATION

6. OVERHEATING

Checkpoint Possible cause Correction

Cooling water Insufficient cooling water Replenish the cooling water

Fan clutch Oil leakage from the fan clutch Replace the fan clutch

Fan belt Fan belt loose or cracked causing slippage Replace the fan belt

Radiator Defective radiator cap or clogged radiator

core

Water pump Defective water pump Repair or replace the water pump

Cylinder head and cylinder body sealing cap

Thermostat Defective thermostat Replace the thermostat

Cooling system Cooling system clogged by foreign material Clean the foreign material from the

Fuel injection timing Fuel injection timing improperly adjusted Adjust the fuel injection timing

Defective sealing cap resulting in water leakage

Replace the radiator cap or clean the

radiator core

Replace the sealing cap

cooling system

7. WHITE EXHAUST SMOKE

Checkpoint Possible cause Correction

Cooling water Insufficient cooling water Replace the cooling water

Fuel Water particles in the fuel Replace the fuel

Fuel injection timing Delayed fuel injection timing Adjust the fuel injection timing

Compression pressure Blown out cylinder head gasket. Worn

cylinder liner. Piston ring sticking

Inlet and exhaust valve Valves seals

Defective valve seals. Worn valves stems and valve guides

Replace the related parts

Replace the valve seals, the valves,

and the valve guides

SERVICE INFORMATION 00 – 11

8. DARK EXHAUST SMOKE

Checkpoint Possible cause Correction

Air cleaner Clogged air cleaner element Clean or replace the air cleaner

element

Injection nozzle Injection nozzle injection starting pressure

too low Improper spray condition

Fuel injection timing Fuel injection timing improperly adjusted Adjust the fuel injection timing

Defective delivery valve resulting in fuel drippage after fuel injection

Excessive injection volume Adjust the injection volume

Adjust or replace the injection nozzle

Replace the delivery valveInjection pump

9. OIL PRESSURE DOES NOT RISE

Checkpoint Possible cause Correction

Engine oil Improper viscosity engine oil.

Insufficient engine oil

Oil pressure gauge or unit Oil pressure indicator light

Oil filter Clogged oil filter element Replace the oil filter element or the oil

Defective oil pressure gauge or unit

Defective indicator light

Replace the engine oil

Correct the engine oil volume

Repair or replace the oil pressure

gauge or unit

Replace the indicator light

filter cartridge

Relief valve and bypass valve

Rocker arm shaft Worn rocker arm bushing Replace the rocker arm bushing

Camshaft Worn camshaft and camshaft bearing Replace the camshaft and the

Crankshaft and bearings

Relief valve sticking and/or weak by-pass valve spring

Clogged oil pump strainer Clean the oil pump strainerOil pump

Worn oil pump related parts Replace the oil pump related parts

Worn crankshaft and bearings Replace the crankshaft and/or the

Replace the relief valve and/or the by-

pass valve spring

camshaft bearing

bearings

00 – 12 SERVICE INFORMATION

10. ABNORMAL ENGINE NOISE

1. ENGINE KNOCKING

Check to see that the engine has been thoroughly warmed up before beginning the troubleshooting procedure.

Checkpoint Possible cause Correction

Fuel Fuel unsuitable Replace the fuel

Fuel injection timing Fuel injection timing improperly adjusted Adjust the fuel injection timing

Injection nozzle Improper injection nozzle starting pressure

and spray condition

Compression pressure Blown out head gasket

Broken piston ring

Adjust or replace the injection nozzle

Replace the head gasket or the piston

ring

2. GAS LEAKAGE NOISE

Exhaust pipes Loosely connected exhaust pipes. Broken

exhaust pipes

Injection nozzles and/or glow plugs

Exhaust manifold Loosely connected exhaust manifold and/or

Cylinder head gasket Damaged cylinder head gasket Replace the cylinder head gasket

Loose injection nozzles and/or glow plugs Replace the washers

glow plugs

Tighten the exhaust pipe connections

Replace the exhaust pipes

Tighten the injection nozzles and/or

the glow plugs

Tighten the exhaust manifold

connections

3. CONTINUOUS NOISE

Fan belt Loose fan belt Readjust the fan belt tension

Cooling fan Loose cooling fan Retighten the cooling fan

Water pump bearing Worn or damaged water pump bearing Replace the water pump bearing

Generator or vacuum pump

Valve clearance Clearance improperly adjust Adjust the valve clearances

Defective generator or vacuum pump Repair or replace the generator or the

vacuum pump

SERVICE INFORMATION 00 – 13

4. SLAPPING NOISE Checkpoint Possible cause Correction

Valve clearance Valve clearance improperly adjusted Adjust the valve clearance

Rocker arm Damaged rocker arm Replace the rocker arm

Flywheel Loose flywheel bolts Retighten the flywheel bolts

Crankshaft and thrust bearings

Crankshaft and connecting rod bearings

Connecting rod bushing and piston pin

Piston and cylinder liner

Worn or damaged crankshaft and/or thrust bearings

Worn or damaged crankshaft and/or connecting rod bearings

Worn or damaged connecting rod bushing and piston pin

Worn or damaged piston and cylinder liner. Replace the piston and the cylinder

Replace the crankshaft and/or the thrust bearings

Replace the crankshaft and/or the connecting rod bearings

Replace the connecting rod bushing and/or the piston pin

liner.

00 – 14 SERVICE INFORMATION

11. ENGINE COOLING TROUBLE

Checkpoint Possible cause Correction

Engine overheating

Low coolant level Replenish

Thermo unit faulty Replace

Faulty thermostat Replace

Faulty coolant unit Repair or replace

Clogged radiator Clean or replace

Faulty radiator cap Replace

Low engine oil level or use of improper engine oil

Damaged cylinder head gasket Replace

Clogged exhaust system Clean exhaust system or replace

Loose fan belt Adjust

Excessive fuel injected Adjust

Improper injection timing Adjust

Replenish or change oil Replenish

faulty parts

Engine overcooling Faulty thermostat Replace

Faulty thermostat ReplaceToo long engine

warm-up time

Thermo unit faulty Replace

12. ENGINE ELECTRICAL PART TROUBLE

STARTER DOES NOT RUN

CHECK BATTERY

SERVICE INFORMATION 00 – 15

CHARGING FAILURE OR LIFE

CHECK BATTERY

CONNECTION FAILURE

CLEAN BATTERY TERMINALS, AND RECONNECT

BATTERY IS NORMAL

CHECK TERMINAL CONNECTION

TERMINAL CONNECTION IS NORMAL

CHECK STARTER OR STARTER SWITCH

FAILURE

REPAIR OR REPLACE

TURN ON HEAD LAMP AND STARTER SWITCH

HEAD LAMP DOES NOT COME ON OR IT IS EXTREMELY DARK

a) LACK OF BATTERY CHARGING b) SHORT-CIRCUIT IN STARTER OIL c) FAULTY STARTER PARTS

HEAD LAMP ILLUMINATES

a) DISCONNECT STARTER CIRCUIT b) DISCONNECT STARTER COIL c) FAULTY STARTER SWITCH

00 – 16 SERVICE INFORMATION

FAULTY MESHING OF PINION AND RING GEAR

CHECK IF BATTERY VOLTAGE IS PRESENT AT MAGNETIC SWITCH TERMINAL “S” WHEN STARTER SWITCH IS TURNED TO “START (ST)”

YES

OR

EXTREME WEAR OF PINION AND RING GEAR

REPAIR OR REPLACE STARTER, REPLACE RING GEAR

STARTER SLIDING RESISTANCE IS LARGE

REPAIR OR REPLACE STARTER

NO

UNDER THIS CONDITION, CHECK IF VOLTAGE OF CONNECTOR 3BW ON MAGNETIC SWITCH OF RESTART RELAY IS NORMAL

YES NO

DISCONNECTION OR FAULTY CONNECTION BETWEEN STARTER SWITCH AND MAGNETIC SWITCH

REPAIR

YES NO

CHECK IF VOLTAGE IS PRESENT AT WIRING CONNECTOR 3BW ON STARTER SWITCH OF RESTART RELAY

FAULTY CONNECTION OF STARTER SWITCH

REPLACE STARTER SWITCH

DISCONNECTION OR FAULTY CONNECTION BETWEEN STARTER SWITCH AND BATTERY

REPAIR

MAGNETIC SWITCH DOES NOT OPERATE THOUGH STARTER SWITCH IS TURNED TO “START (ST)”

CHECK IF VOLTAGE IS PRESENT AT MAGNETIC SWITCH TERMINAL “S” WHEN STARTER SWITCH IS TURNED TO “START (ST)”

SERVICE INFORMATION 00 – 17

YES

CHECK GROUND CABLE

YES NO

REPAIR

OR

PINION SLIDING PART DOES NOT MOVE

MAGNETIC SWITCH OR COIL IS DISCONNECTED OR BURNED OUT

NO

CHECK IF INDICATOR LAMP ON METER COMES ON NORMALLY

YES NO

CHECK CONTINUITY STARTER SWITCH AND MAGNETIC SWITCH TERMINAL “S”

CHECK STARTER RELAY

FAULTY CONNECTION OR STARTER SWITCH

DISCONNECTION OR FAULTY CONNECTION BETWEEN BATTERY AND STARTER SWITCH

REPAIR

REPAIR OR REPLACE STARTER

CHECK CLUTCH START

REPLACE STARTER SWITCH

00 – 18 SERVICE INFORMATION

PINION MESHES WITH RING GEAR BUT ENGINE DOES NOT RUN

CHECK GROUND CABLE

YES

FAULTY CONNECTION OF BRUSH AND COMMUTATOR

REPAIR OR REPLACE STARTER

BURNED-OUT MAGNETIC STARTER SWITCH

NO

REPAIR OR REPLACE GROUND CABLE

DISCONNECTION OR DAMAGE OF FIELD COIL

DISCONNECTION OR DAMAGED OF ARMATURE COIL

SLIP OF PINION CLUTCH

SERVICE INFORMATION 00 – 19

STARTER DOES NOT STOP THOUGH STARTER SWITCH IS RETURNED TO “ON” FROM “START”

DISCONNECTED STARTER SWITCH WIRING CONNECTOR, AND CHECK STARTER SWITCH OPERATION.

KEY POSITION

LOCK

OFF

ACC

ON

START

THERE MUST BE NO CONTINUITY EXCEPT ABOVE LINES.

YES

MAGNETIC SWITCH CONTACTS ARE FUSED AND NOT MOVED, OR A RETURN SPRING IS BROKEN OR DETERIORATED

BATTERY

B1

IGNITION

IG1

BATTERYB2ACCESSORIES

ACC

IGNITION

NO

REPLACE STARTER SWITCH

IG2

STARTER

ST

REPLACE MAGNETIC SWITCH

00 – 20 SERVICE INFORMATION

1) ENGINE HAS LESS THAN NORMAL POWER

Checkpoint Trouble Cause Countermeasure

13. TURBOCHARGER

Air cleaner Restricted Clean or replace

OKOK

Intake pipe and hose Restricted Clean or replace

OK

Compressor/Intake manifold Loose (Leaking) Repair

OK

Exhaust manifold/turbine inlet Loose (Leaking) Repair

OK

NG

Exhaust piping and silencers Restricted Clean or replace

OK

Air breather Restricted Clean or replace

OK

Boost compensator

(Injection pump)

Continued on the next page

NG

Defective Repair or replace

Checkpoint Trouble Cause Countermeasure

Continued from the previous page

OK

SERVICE INFORMATION 00 – 21

Compressor wheel Impact damage Replace

OKOK

Turbine wheel Impact damage Replace

OK

Rotating assembly Dragging or seized Replace

NG

Carbon build-up Replace

NG

00 – 22 SERVICE INFORMATION

Checkpoint Trouble Cause Countermeasure

2) BLUE OR BLACK SMOKE

Air cleaner or intercooler Restricted Clean, repair, or replace

OKOK

Turbocharger oil seal Leakage Replace

OK

Turbocharger oil drain pipe Restricted Repair or replace

OK

Air breather Restricted Clean

OK

NG

Boost compensator

(Injection pump)

OK

Compressor wheel Impact damage Replace

OK

Turbine wheel Impact damage Replace

Continued on the next page

NG

Defective Repair or replace

NG

Checkpoint Trouble Cause Countermeasure

Continued from the previous page

OK

SERVICE INFORMATION 00 – 23

Center housing oil drain passage Restricted Clean or replace

NG

00 – 24 SERVICE INFORMATION

Checkpoint Trouble Cause Countermeasure

3) EXCESSIVE OIL CONSUMPTION

Air breather Restricted Clean

OKOK

Boost compensator

(Injection pump)

OK

Turbocharger oil seal Leakage Replace

OK

Turbocharger oil drain pipe Restricted Clean or replace

OK

NG

Defective Repair or replace

NG

Turbine wheel Impact damage Replace

OK

Compressor wheel Impact damage Replace

OK

Oil pressure Excessive Repair

Continued on the next page

NG

Checkpoint Trouble Cause Countermeasure

Continued from the previous page

OK

SERVICE INFORMATION 00 – 25

Center housing oil drain passage

NG

Restricted Clean or replace

00 – 26 SERVICE INFORMATION

4) EXCESSIVE TURBOCHARGER NOISE

Checkpoint Trouble Cause Countermeasure

Intake and exhaust

system joints

OKOK

Intake and exhaust system

gaskets

OK

Turbocharger rotating parts Rough rotation Replace

Compressor wheel

NG

Restricted Repair

Damaged Replace

Rubbing against housing Repair or replace

OK

Turbine wheel

Continued on the next page

NG

Damaged Replace

Rubbing against housing Repair or replace

Damaged Replace

Carbon deposits Clean or replace

Checkpoint Trouble Cause Countermeasure

Continued from the previous page

OK

SERVICE INFORMATION 00 – 27

Oil level Too low Correct

OK

Turbocharger oil feed pipe Restricted Repair or replace

OK

Turbine housing Carbon deposits Clean

OK

NG

Contaminated Replace oil

NG

Compressor housing Dirty Clean

OK

Turbine shaft bearings Worn Replace

NG

00 – 28 SERVICE INFORMATION

5) EXCESSIVE ROTATING PART WEAR

Checkpoint Trouble Cause Countermeasure

Engine oil Contaminated Change

OK

Turbocharger oil feed pipe Restricted Clean or replace

OK

Turbocharger oil seal Defective Replace

OK

NG

Wrong grade or type Change

NG

Center housing oil

drain passage

OK

Turbine shaft Oil sludge and coking Replace

OK

Engine lubrication system Inadequate oil supply Correct

NG

Restricted Clean or replace

NG

LUBRICATION CHART

4JB1, 4JB1TC, 4JG2, Oil Filter & Oil Cooler

SERVICE INFORMATION 00 – 29

kPa (Kg/cm2/psi)

!

Oil filter relief valve opening pressure : 559 - 0618 (5.7 - 6.3/81 - 90)

"

Oil cooler safety valve opening pressure : 314 - 373 (3.2 - 3.8/46 - 54)

#

Oil filter safety valve opening pressure : 78 - 118 (0.8 - 1.2/11 - 19)

$

Oil pressure switch opening pressure : 29.4 - 49.0 (0.3 - 0.5/4.3 - 7.1)

Lubu Chart 5J.tif

The 4J Series engine lubricating system is a full flow type. Lubricating oil is pumped from the oil pump to the cylinder body oil gallery through the oil cooler and the oil filter

(replaceable type oil filters have on oil cooler). It is then delivered to the vital parts of the engine from the cylinder body oil gallery.

00 – 30 SERVICE INFORMATION

MAIN DATA AND SPECIFICATIONS

Item

Engine type Four-cycle, overhead valve, water cooled

Combustion chamber type Direct injection In direct injection

Cylinder liner type Dry type, chrome plated, stainless steel tube

Timing train system Gear drive Gear and Belt Drive

No. of cylinders - Bore x stroke mm (in) 4 - 93 x 102

No. of piston rings Compression rings: 2 / Oil ring: 1

Total piston displacement cm3 (in3) 2,771 (169.0) 3,059 (186.6)

Compression ratio (to 1) 18.2 (4JB1)

Compression pressure kPa (kg/cm2/psi) 3,038 (31 / 441) 3,334 (34 / 483.8)

Engine weight (Dry) N (kg/lb) Approximately

Fuel injection order 1 - 3 - 4 - 2

Engine Model

4JB1 / 4JB1T / 4JB1TC 4JG2 (G. EXP & EC)

4 - 95.4 x 107

(3.66 x 4.02)

18.1 (4JB1T/4JB1TC)

(For EC 2,363 (24.1 / 531))

2,245 (229 / 505) (4JB1)

2,511 (256 / 564)

(4JB1T/4JB1TC)

(3.76 x 4.21)

20.1

Approximately

2,403 (245 / 540)

Fuel injection timing deg BTDC 14 (4JB1)

BTDC 12 (’91/542A) (4JB1)

BTDC 11 (4JB1T)

BTDC 4 (4JB1TC)

Specified fuel type SAE No. 2 diesel fuel

Idling speed rpm 750 - 790 700 – 740

Valve clearances (At cold): Intake mm(in) 0.40 (0.016)

Exhaust mm(in) 0.40 (0.016)

Valve clearances (At hot): Intake mm(in) 0.45 (0.018)

Exhaust mm(in) 0.45 (0.018)

Intake valves Open at (BTDC) deg 24.5

Close at (ATDC) deg 55.5

Exhaust valves Open at (BTDC) deg 54

Close at (ATDC) deg 26

NOTE: G.EXP : General Export Model

EC : European Countries Emission Gas Control Standard ’91/542A : Euro 1 ’91/542B : Euro 2

ATDC 1 (Belt ’91/542A)

TDC 0° (Belt ’91/542B)

ATDC 2 (Gear ’91/542A)

SERVICE INFORMATION 00 – 31

Item

Lubricating system

Lubrication method Pressurized circulation

Specified engine oil (API grade) CC (4JB1)

Oil pump type Gear

Oil filter type Disposable cartridge (Spin-on) Paper element

Oil capacity (Including oil filter)

Oil cooler type Water cooled

Fuel system

Injection pump type Bosch distributor

Governor type Mechanical (Partially variable speed) (For EC Variable speed)

Injection nozzle type Hole Pinttle

Injection nozzle kPa (kg/cm2/psi) opening pressure

Engine Model

lit (US/UK gal) 6.6 - 7.1 (1.74 - 1.87/2.62 - 2.82)

4JB1 / 4JB1T / 4JB1TC 4JG2 (G. EXP & EC)

CC

CD (4JB1T/4JB1TC)

(For EC 6.2 - 8.2 (2.17 - 1.64 / 1.36 - 1.80))

18,142 (185 / 2,631)

(4JB1/4JB1T)

14,710 (150/2,133)

1st: 19,500 (199 / 2,830) 2nd: 26,500 (270 / 3,840)

(4JB1TC)

Main fuel filter type Cartridge paper element and water separator

Air cleaner type Dry paper element

Generator capacity V-A (W) 12 - 40 (480) and 12 - 50 (600) 12 - 50 (600)

(For EC 12 - 60 (720))

Starter motor output V-kW 12 - 2.0 and 12 - 2.2 12 - 2.2

(For EC 12 - 2.0)

Turbocharger IHI RHB5 (4JB1T)

IHI RHF4 (4JB1TC)

00 – 32 SERVICE INFORMATION

Engine Cooling

Cooling system Radiator Heat radiation capacity kcal/h Heat radiation area m Front area m

2

(ft2)

2

(ft2) Dry weight N (Kg/lb) Radiator cap Valve opening pressure kPa (Kg/cm

2

/psi) Coolant capacity lit (Imp.qt./US qt.)

88.2 - 116.7 (0.899 - 1.199/12.78 - 17.05)

Coolant forced circulation

(2 tube in row) Tube type Corrugated

71400

11.78 (126.8)

0.216 (2.325)

105 (10.7/23.6)

3.1 (2.73/3.28)

(For EC 5.8 (5.1/6.13))

Coolant pump Pulley type Pulley ratio

Thermostat type

Centrifugal impeller type

1.2

wax pellet with jiggle valve.

Without jiggle valve (Thailand only) Valve opening °C (°F) Valve full open °C (°F)

82 (180) 95 (203)

Coolant total capacity Iit (Imp.qt./US qt.) 10 (8.80/10.57) (For EC 7.3 (6.42/7.71))

Starting System

Manufacturer DENSO

Engine Model 4JB1 / 4JB1T / 4JB1TC 4JG2 (G.EXP & EC)

Rating

Voltage V 12 Output kW 2.0 2.2 Time Sec 30 Number of tooth of pinion 9

Rotating direction (as viewed from pinion) Clockwise

Weight (approx.) kg 4.6 5.4

No-load characteristics

Voltage/current V/A Speed rpm

11.5/100 or less 3700 or more

Load characteristics

Voltage/current V/A Torque N•m(Kg•m/lb•ft)

7.5/500 or less

13.7 (1.4/10.1)

Speed rpm 1200 or more 1400 or more

Locking characteristics

Voltage/current V/A Torque N•m(Kg•m/lb•ft)

2.4/800 or less

18 (1.8/13) or more

2.0/850 or less

16 (1.6/12) or more

SERVICE INFORMATION 00 – 33

Charging System

Manufacturer HITACHI LR150-449B DENSO

Rated voltage V 12 12

Rated output A 50 40

Rotating direction (As viewed from pulley)

Pulley effective diameter mm (in) 80 (3.15) 82 (3.23)

Weight (with pump) kg (lb) 6.0 (13.27)

Clockwise Clockwise

6.7 (14.77)

4JB1TC for G.E

4JB1TC for EC

4JB1TC for Thailand

00 – 34 SERVICE INFORMATION

SERVICE STANDARD

Engine Mechanical

Parts Items

Cylinder Head

Valve Spring

Cylinder head deck, and exhaust manifold mating surface for flatness

Cylinder head height 92.0 (3.622) 91.55 (3.6043)

Cylinder Head Lower Face Warpage.

Manifold Warpage.

Hot plug sinking

Hot plug exert pressure

Free height

Squareness

Service standard Service limit

4JG2

0.05 (0.002) or less 0.2 (0.0079)

0.05 (0.002)or less

0.05 (0.002) or less

4,500 – 5,500 kg

(9922.5 - 12127.5 lbs)

48.0 (1.891)

4JB1 / 4JB1T /

4JB1TC

-

4JG2

0.20 (0.008)

0.02 (0.0008)

-

47.10 (1.856)

1.7 (0.067)

4JB1 / 4JB1T /

4JB1TC

mm (in)

Remarks

Cannot be Reground

Valve and Valve Guide

Spring tension N (kg/lb)

Diameter Valve Stem

IN

EX

Valve and valve guide clearance IN

EX

Valve guide upper end height (Measured from the Cylinder head upper face)

Valve guide margin

Valve thickness IN

EX

Valve seat contact surface angle

296 (30.2/66.4)

7.946 - 7.961

(0.3128 - 0.3134)

7.921 - 7.936

(0.3118 - 0.3124)

0.039 - 0.069

(0.0015 - 0.0027)

0.064 - 0.096

(0.0025 - 0.0038)

13.0 (0.512)

1.1 (0.0433)

1.41 (0.0556)

1.39 (0.0547)

1.79 (0.0705)

1.83 (0.0720)

45°

257.9 (26.3/57.9) At installed

7.880 (0.3102)

7.850 (0.3090)

0.200 (0.0079)

0.250 (0.0098)

-

1.6 (0.0630)

1.1 (0.0433)

1.5 (0.06)

height

38.9 (1.531)

Valve seat contact width

IN

EX

1.7 (0.0669)

2.0 (0.0787)

2.2 (0.0866)

2.5 (0.0984)

SERVICE INFORMATION 00 – 35

Service standard Service limit

Parts Items

4JG2

Push rod Curvature - 0.4 (0.0157) or less

4JB1 / 4JB1T /

4JB1TC

4JG2

4JB1 / 4JB1T /

4JB1TC

mm (in)

Remarks

Camshaft End play

Cam lobe height

Journal diameter

Runout

Camshaft bearing inside diameter

Camshaft oil clearance

Tappet Outside diameter

Oil clearance (Between tappet and cylinder body)

Rocker arm Assembly

Rocker shaft outside diameter

Rocker arm inside diameter

Oil clearance (Between rocker arm and rocker shaft)

0.08 (0.0031)

42.02 (1.6543)

49.945 - 49.975(1.9663-1.9675)

0.02 (0.0008) or less

50.000 - 50.030

(1.9685 - 1.9697)

0.025 - 0.085

(0.0098 - 0.00334)

12.97 - 12.99 (0.5106 - 0.5114)

0.03 (0.0118)

18.98 - 19.00

(0.7472 - 0.7480)

19.036 - 19.060

(0.7494 - 0.7504)

0.06 - 0.08

(0.00235 - 0.00315)

0.2 (0.0079)

41.65 (1.6397)

49.60 (1.9527)

0.10 (0.0039)

50.08(1.9716)

0.12 (0.0047)

12.95 (0.5098)

0.10 (0.0039)

18.90 (0.7440)

19.10 (0.7520)

0.10 (0.004)

Rocker shaft runout

Oil clearance Body and gear Body cover and gear 0.06 (0.0024) 0.02 - 0.07

Crankshaft Thrust clearance 0.10 (0.0039) 0.30 (0.018)

Main bearing clearance (Between main bearing and Crankshaft)

Crankshaft runout

Main journal diameter

Crankshaft pin diameter

Crankshaft Journal and Crank Pin uneven wear

Crank Pin and Bearing Clearance.

0.14 (0.0055) 0.13 - 0.14

0.031-0.063

(0.0012-0.0025)

0.05 (0.00197) or less

69.917 - 69.932 (2.7526 - 2.7532)

52.915 - 52.930 (2.0833 - 2.0839)

0.05 (0.002) or less

0.029 - 0.066 (0.0011 - 0.0026)

-

(0.0051-0.0055)

(0.0008-0.0028)

0.035-0.080

(0.0014-0.0032)

0.2 (0.0079) or less

0.20 (0.0079) 0.15 (0.0059)Oil pump

0.15 (0.0059)

0.11

(0.0043)

0.08 (0.0031)

69.91 (2.7524)

52.90 (2.0827)

0.08 (0.003)

0.100 (0.0039)

00 – 36 SERVICE INFORMATION

Parts Items

Service standard Service limit

4JG2

4JB1 / 4JB1T /

4JB1TC

4JG2

4JB1 / 4JB1T /

4JB1TC

mm (in)

Remarks

Piston pin, Piston ring and Connecting rod

Piston diameter 95.365 - 95.404

(3.7545-3.9039) Piston Clearance (Between piston and Cylinder liner)

Piston ring gap 1st

Piston ring clearance 1st

0.047 - 0.065

(0.0019-0.0026)

(0.0079 –

2nd

(0.0146 -

Oil

(0.0079 -

(0.0035 -

2nd

(0.002 -

0.20 - 0.35

0.0138)

0.37 - 0.52

0.0205)

0.20 - 0.40

0.00157)

0.09 - 0.13

0.0051)

0.05 - 0.09

0.0035)

92.985 - 93.024

(3.6600-3.6623)

0.025 - 0.045

(0.0010-0.0018)

0.20 - 0.40

(0.0079 –

0.0157)

0.20 - 0.40

(0.0079 -

0.00157)

0.10 - 0.30

(0.0039 -

0.0118)

0.090 - 0.125

(0.0035 -

0.0049)

0.050 - 0.075

(0.0020 -

0.0030)

-Piston,

-

1.5 (0.0591)

0.15 (0.0059)

Oil 0.03 - 0.07

(0.0012 - 0.0028)

Piston pin diameter 33.995 - 34.000

(1.3384-1.3386)

Fitting interference (Between connecting rod and piston pin)

Fitting interference (Between piston and piston pin)

Connecting rod alignment Bend

Twist

Piston pin and Connecting Rod Bushing Clearance

Connecting rod thrust clearance

Oil clearance (Between crank pin and Connecting rod) 0.0033) 0.0026)

0.029 -0.083 0.029 - 0.066 0.100 (0.0039)

(0.0014 - (0.0011 -

0.008 - 0.020

(0.0003 - 0.0008)

0.002 - 0.015

(0.0001 - 0.0006)

0.08 (0.0031) or less

0.05 (0.0020) or less

0.008 - 0.020

(0.0003 - 0.0008)

0.230 (0.0091)

30.995 - 31.000

(1.2202-1.2204)

0.15 (0.0059)

33.970

(1.3374)

0.05 (0.0020)

0.04 (0.0016)

0.20 (0.0079)

0.15 (0.0059)

0.050 (0.0020)

0.35 (0.0138)

30.970

(1.2190)

Per 100

(3.94)

Per 100

(3.94)

Parts Items

SERVICE INFORMATION 00 – 37

Service standard Service limit

4JG2

4JB1 / 4JB1T /

4JB1TC

4JG2

4JB1 / 4JB1T /

4JB1TC

mm (in)

Remarks

Cylinder Block

Warpage (Upper surface of the cylinder block)

Cylinder bore diameter 97.000 - 97.040 95.011 - 95.040

(3.8189 - (3.7406 -

3.8205) 3.7417)

Cylinder liner projection 0.0-0.1

Cylinder liner inside 95.420 - 95.460 93.020 - 93.060 diameter (3.7567 - (3.6622 -

3.7583) 3.6638)

Cylinder liner outside 97.011-97.050 95.011 - 95.050 diameter (3.8193 - (3.7405 -

3.8209) 3.7421)

- 0.20 (0.0079)

(0.00-0.0039)

00 – 38 SERVICE INFORMATION

SERVICING

Servicing refers to general maintenance procedures to be performed by qualified service personnel.

MODEL IDENTIFICATION

Engine Serial Number

The engine number is stamped on the front left hand side of the cylinder body.

0038-1.tif

AIR CLEANER

Dry Type Paper Element

Element cleaning procedures will vary according to the condition of the element.

0038-2.tif

Dust fouled Element

Rotate the element with your hand while applying compressed air to the inside of the element. This will blow the dust free.

Compressed air pressure kPa (kg/cm

392 - 490 (4 - 5/57 - 71)

CAUTION

Do not bang the element against another object in an attempt to clean it. Damage to the element will result.

Carbon and Dust Fouled Element

1. Prepare a cleaning solution of Isuzu Genuine Element Cleaner (Donaldson D1400) diluted with water.

2. Submerge the element in the solution for twenty minutes.

2

/Psi)

0038-3.tif

0039-1.tif

SERVICE INFORMATION 00 – 39

3. Remove the element from the solution and rinse it well with running water.

Water pressure must not exceed 274 kPa (2.8 kg/cm /40Psi)

4. Dry the element in a well ventilated area. An electric fan will hasten drying.

NOTE:

Do not use compressed air or an open flame to dry the element quickly. Damage to the element will result. It will usually take two or three days for the element to dry completely. Therefore, it is a good idea to have a spare on hand to use in the interim.

2

0039-2.tif

050LX001.tif

LUBRICATING SYSTEM

Main Oil Filter (Cartridge Type Paper Element) Replacement Procedure

1. Loosen the used oil filter by turning it counterclockwise with the filter wrench.

2. Clean the oil filter fitting face. This will allow the new oil filter to seat properly.

3. Apply a light coat of engine oil to the O-ring.

4. Turn in the new oil filter until the filter O-ring is fitted against the sealing face.

5. Use the filter wrench to turn in the filter an additional 1 and 1/4 turns.

Filter Wrench : 5-8840-0200-0 (89mm/3.5in)

5-8840 0202-0 (106mm/4.2in) 5-8840-2209-0 (100.6mm/4.0in)

6. Check the engine oil level and replenish to the specified level if required.

Replenishment Engine Oil lit (Imp qt/US qt)

0.7 (0.62/0.74)

0039-4.tif

7. Start the engine and check for oil leakage from the main oil filter.

00 – 40 SERVICE INFORMATION

FUEL SYSTEM

Fuel Filter Replacement Procedure

1. Loosen the used fuel filter by turning it counterclockwise with the filter wrench.

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

0040-1.tif

2. Clean the filter cover fitting faces. This will allow the new fuel filter to seat properly.

0040-2.tif

0040-3.tif

0040-4.tif

3. Turn in the fuel filter until the sealing face comes in contact.

4. Turn in the fuel filter an additional 2/3 of a turn with a filter wrench.

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

5. Loosen the bleeder plug on the injection pump overflow valve.

6. Operate the priming pump until fuel begins to flow from the fuel filter.

7. Retighten the bleeder plug.

8. Operate the priming pump several times and check for fuel leakage.

NOTE:

The use of an ISUZU genuine fuel filter is strongly recommended.

0041-1.tif

Fuel Filter Water Draining Procedure

The indicator light will come on when the water level in the water separator exceeds the specified level.

Drain the water and foreign material from the water separator with the following procedure.

0041-2.tif

SERVICE INFORMATION 00 – 41

1. Find a safe place to park the vehicle.

2. Open the engine hood and place a container (Approximately 0.2 liter capacity) at the end of the vinyl hose beneath the drain plug on the separator.

3. Loosen the drain plug by turning it counterclockwise (Approximately 5 turns) and operate the priming pump up and down about 10 times until water is drained approximately 0.1 liter.

4. After draining, securely tighten the drain plug by turning it clockwise and operate the priming pump manually up and down several times.

5. After starting the engine, check to see that there is no fuel leak from the drain plug. Also check to see that the fuel filter water indicator light has turned off.

If water separator requires frequent draining, have the fuel tank drained for removal of water at your Isuzu Dealer.

Air Bleeding

1. Loosen the bleeder screw on the injection pump overflow valve.

2. Operate the priming pump until fuel mixed with foam flows from the bleeder screw.

3. Tighten the bleeder screw.

4. Operate the priming pump several times and check for fuel leakage.

0041-3.tif

0041-4.tif

0042-1.tif

COOLING SYSTEM

Coolant Level

Check the coolant level and replenish the radiator reserve tank as necessary.

If the coolant level falls below the “MIN” line, carefully check the cooling system for leakage. Then add enough coolant to bring the level up to the “MAX” line.

Engine coolant change procedure

1. To change engine coolant, make sure that the engine

is cool.

WARNING:

When the coolant is heated to a high temperature, be sure not to loosen or remove the radiator cap. Otherwi se you might get scalded by hot vapor or boiling water. To open the radiator cap, put a piece of thick cloth on the cap and loosen the cap slowly to reduce the pressure when the coolant has become cooler.

2 Open radiator cap and drain the cooling system by

loosening the drain valve on the radiator and on the cylinder body.

00 – 42 SERVICE INFORMATION

NOTE:

For best result it is suggested that the engi ne cooling system be flushed at least once a year. it is advisable to flush the interior of the cooling system including the radiator before using antifreeze (ethylene-glycol based).

Replace damaged rubber hoses as the engine anti-freeze coolant is liabl e t o l eak out even minor cracks. Isuzu recommends to use lsuzu genuine anti-freeze (ethylene-glycol based) or equivalent, for the cooling system and not add any inhibitors or additives.

CAUTION: A failure to correctly fill the engine cooling

system in changing or topping up coolant may sometimes cause the coolant to overflow f r om the filler neck even before the engine and radiator are completely full. If the engine runs under this condition, shortage of coolant may possibly result in engine overheating. To avoid such trouble, the following precautions should be taken in filling the system.

3 To refill engine coolant, pour coolant up to filler neck

using a filling hose which is smaller in outside diameter of the filler neck. Othewise air between the filler neck and the filling hose will block entry, preventing the system from completely filling up.

4 Keep a filling rate of 9 liter/min. or less. Filling over

this maximum rate may force air inside the engine and radiator. And also, the coolant overflow will increase, making it difficult to determine, whether or not the system is completely full.

5 After filling the system to the full, pull out the filling

hose and check to see if air trapped in the system is dislodged and the coolant level goes down. Should the coolant level go down, repeat topping-up until there is no more drop in the coolant level.

6 After directly filling the radiator, fill the reservoir to the

maximum level.

7 Install and tighten radiator cap and start the engine.

After idling for 2 to 3 minutes, stop the engine and reopen radiator cap. If the water level is lower, replenish.

WARNING: When the coolant is heated to a high

temperature, be sure not to loosen or remove the radiator cap. Otherwi se you might get scalded by hot vapor or boiling water. To open the radiator cap, put a piece of thick cloth on the cap and loosen the cap slowly to reduce the pressure when the coolant has become cooler.

8 After tightening radiator cap, warm up the engine at

about 2,000 rpm. Set heater adjustment to the highest temperature position, and let the coolant circulate also into heater water system.

9 Check to see the thermostat has opened through the

0042-2.tif

0042-3.tif

SERVICE INFORMATION 00 – 43

needle position of water thermomete, conduct a 5 minutes idling again and stop the engine.

10 When the engine has been cooled, check filler neck

for water level and replenish if required. Should extreme shortage of coolant is found, Check the coolant system and reservoir tank hose for leakage.

11 Fill the coolant into the reservoir tank up to “MAX”

line.

Cooling System Inspection

Install a radiator filler cap tester to the radiator. Apply testing pressure to the cooling system to check for leakage.

The testing pressure must not exceed the specified pressure. Testing Pressure kPa (Kg/cm2/psi)

147 (1.5/21)

Radiator Cap Inspection

The radiator filler cap is designed to maintain coolant pressure in the cooling system at 1.05 kg/cm kPa). Check the radiator filler cap with a radiator filler cap tester. The radiator filler cap must be replaced if it fails to hold the specified pressure during the test procedure.

Radiator Filler Cap Pressure Pressure Valve kPa (Kg/cm

Negative Valve (Reference) kPa (Kg/cm2/psi)

88 - 118 (0.9 - 1.2/12.8 - 17.1)

1.0 - 13.9 (0.01 - 0.04/0.14 - 0.57)

2

(15 psi / 103

2

/psi)

0042-4.tif

Thermostat Operating Test

1. Completely submerge the thermostat in water.

2. Heat the water. Stir the water constantly by suitable wood bar (2) to avoid direct heat being applied use wood plate (3) to the thermostat.

3. Check the thermostat initial opening temperature.

Thermostat Initial Opening Temperature °C (°F)

4. Check the thermostat full opening temperature.

Thermostat Full Opening Temperature °C (°F)

Valve Lift at Fully Open Position mm (in)

82 (180)

95 (203)

10 (0.39)

00 – 44 SERVICE INFORMATION

0043-1.tif

Drive Belt Adjustment

Depress the drive belt mid portion with a 98N (10 kg/22 lb) force.

Drive Belt Deflection mm (in)

10 (0.39)

Check the drive belt for cracking and other damage.

1. Crankshaft damper pulley

2. Generator pulley

3. Cooling fan pulley

4. Oil pump pulley or idler pulley

5. Compressor pulley or idle pulley

Cooling Fan Pulley Drive Belt

Fan belt tension is adjusted by moving the generator. Depress the drive belt mid portion with a 98N (10 kg/22

lb) force.

1. Crankshaft damper pulley

2. Generator pulley

3. Cooling fan pulley

0043-2.tif

0043-3.tif

0043-4.tif

Compressor Pulley Drive Belt

Move the idler pulley as required to adjust the compressor drive belt tension.

If the vehicle is equipped with power steering, move the oil pump as required.

Depress the drive belt mid portion with a 98N (10 kg/22 lb) force.

Belt Deflection mm (in)

14 - 17 (0.55 - 0.67)

1. Crankshaft damper pulley

2. Oil pump pulley or idler pulley

Power Steering Oil Pump Pulley Drive Belt

Move the oil pump as required to adjust the oil pump drive belt tension.

On air conditioner equipped models, both drive belts pulley must always be replaced as a set.

Depress the drive belt mid portion with a 98N (10 kg/22 lb) force.

Belt Deflection mm (in)

1. Crankshaft damper pulley

2. Oil pump pulley

3. Compressor pulley or idler pulley

14 - 17 (0.55 - 0.67)

SERVICE INFORMATION 00 – 45

ENGINE CONTROL

Idling Speed Inspection

1. Set the vehicle parking brake and choke the drive wheels.

2. Place the transmission in neutral.

3. Start the engine and allow it to warm up.

4. Disconnect the engine control cable from the control lever.

5. Set a tachometer to the engine.

6. Check the engine idling speed. If the engine idling speed is outside the specified

range, it must be adjusted.

Engine Idling Speed rpm

4JB1 / 4JB1T / 4JB1TC 750 - 790

4JG2 700 - 740

Idling Speed Adjustment

0044-1.tif

1. Loosen the idling set bolt lock nut on the injection pump idling set bolt.

2. Adjust the idling speed to the specified range by turning the idling set bolt.

3. Lock the idling set bolt with the idling set bolt lock nut.

4. Check that the idling control cable is tight (free of slack).

If required, remove the slack from the cable.

Accelerator Control Cable Adjustment

1. Loosen the accelerator cable clamp bolt.

2. Check that the idling control knob on the instrument panel is in the engine idling position.

3. Hold the accelerator lever in the fully closed position and stretch the control cable in the direction indicated by the arrow to remove any slack.

Accelerator Pedal Adjustment

1. Loosen the lock nut.

2. Adjust bolt height from floor.

Adjust Bolt Height A mm (in)

18 - 28 (0.71 - 1.1)

0044-2.tif

00 – 46 SERVICE INFORMATION

0045-1.tif

1. Hold the accelerator pedal pad securely by hand, and give it a full stroke.

2. Adjust the stopper bolt so that the clearance between the pad stopper bolt and the rear side of the pad becomes the specified length.

0 - 2 (0 - 0.079)

mm (in)

3. Check to see if the accelerator pedal play is in the range of 5 to 10mm above the pedal pad.

4. Press down on the accelerator pedal fully and check to see if the engine rotates at its maximum speed with each of the linkage in the smooth operation.

5. In the operating range of accelerator pedal and the injection pump lever returns to their respective original positions without fail.

VALVE CLEARANCE ADJUSTMENT

1. Bring the piston in either the No. 1 cylinder or the No. 4 cylinder to TDC on the compression stroke by turning the crankshaft until the crankshaft damper pulley TDC line is aligned with the timing pointer.

0045-2.tif

0045-3.tif

0045-4.tif

2. Check the rocker arm shaft bracket nuts for looseness.

Tighten any loose rocker arm shaft bracket nuts before adjusting the valve clearance.

Rocker Arm Shaft Bracket Nut Torque N∙m (kg∙m/lb∙ft)

54 (5.5/40)

3. Check for play in the No. 1 intake and exhaust valve push rods.

If the No. 1 cylinder intake and exhaust valve push rods have play, the No. 1 piston is at TDC on the compression stroke.

If the No. 1 cylinder intake and exhaust valve push rods are depressed, the No. 4 piston is at TDC on the compression stroke.

0046-1.tif

SERVICE INFORMATION 00 – 47

Adjust the No. 1 or the No. 4 cylinder valve clearance while their respective cylinders are at TDC on the compression stroke.

Valve Clearance (At Cold) mm (in)

0.4 (0.016)

4. Loosen each valve clearance adjusting screw as shown in the illustration.

5. Insert a feeler gauge of the appropriate thickness between the rocker arm and the valve stem end.

6. Turn the valve clearance adjusting screw until a slight drag can be felt on the feeler gauge.

7. Tighten the lock nut securely.

8. Rotate the crankshaft 360°.

9. Realign the crankshaft damper pulley TDC notched line with the timing pointer.

10. Adjust the clearance for the remaining valves as shown in the illustration.

0046-2.tif

0046-3.tif

0046-4.tif

INJECTION TIMING ADJUSTMENT

1. Check that the notched line on the injection pump flange is aligned with the front plate or the timing gear case notched line.

2. Bring the piston in the No. ! cylinder to TDC 1 on the compression stroke by turning the crankshaft until the crankshaft pulley TDC line is aligned with the timing

"

mark

Note:

Check for play in the No. 1 intake and exhaust valve push rods. If the No. 1 cylinder intake and exhaust valve push rods have play, the No. 1 piston is at TDC on the compression stroke.

.

0046-5.tif

3. Disconnect the injection pipe from the injection pump.

4. Remove one bolt from the distributor head.

5. Insert a screwdriver into a hole in the fast idle lever and turn the lever to release the W-C.S.D. function. (If so equipped)

6. Install the static timing gauge

#

.

The probe of the gauge should be depressed inward approximately 2 mm (0.079 in).

Static Timing Gauge : 5-8840-0145-0 (J-28827)

00 – 48 SERVICE INFORMATION

0047-1.tif

0047-2.tif

7. Rotate the crankshaft to bring the piston in the No. 1 cylinder to a point 30 - 40° BTDC.

8. Set the timing gauge needle to zero.

9. Move the crankshaft pulley slightly in both directions to check that the gauge indication is stable.

10. Turn the crankshaft clockwise and read the gauge indication when the crankshaft pulley timing mark is aligned with the pointer.

mm (in)

4JB1 BTDC 14°

4JB1T BTDC 11°

4JB1TC BTDC 4°

4JG2 ATDC 2°

Standard Reading mm (in)

0.5 (0.02)

0047-3.tif

If the injection timing is outside the specified range, continue with the following steps.

11. Loosen the injection pump fixing nuts and bracket bolts.

12. Adjust the injection pump setting angle.

When large than

standard value

When smaller than

standard value

Gear drive A B

A : Move the injection pump toward the engine. B : Move the injection pump away from the engine. Tighten the pump fixing nut, adjust bolt and pump

distributor head plug to the specified torque. Pump Fixing Bolt N∙m (kg∙m/lb∙ft)

Adjust Bolt N∙m (kg∙m/lb∙ft)

24 (2.4/17)

19 (1.9/14)

Injection Pump Distributor Head Plug N∙m (kg∙m/lb∙ft)

17 (1.7/12)

CAUTION

• When installing the distributor head/plug, be sure to use new copper washer.

0048-1.tif

SERVICE INFORMATION 00 – 49

COMPRESSION PRESSURE MEASUREMENT

1. Start the engine and allow it to idle until the coolant temperature reaches 70 - 80°C (158 - 176°F).

2. Remove the following parts. * Glow plugs * Fuel cut solenoid connector * QOS (Quick-On Start System) fusible link wire at

the connector.

3. Set the adapter and compression gauge to the No. 1 cylinder glow plug hole.

Compression Gauge (with Adapter): 5-8840-2008-0 (J-29762) Adapter: 5-8531-7001-0

4. Turn the engine over with the starter motor and take the compression gauge reading.

Compression Pressure at 200 rpm kPa (Kg/cm

Standard Limit

2

/psi)

0048-2.tif

0048-3.tif

4JB1 3,038 (31/441) 2,157 (22/313)

4JG2 3,334 (34/484) 2,452 (25/356)

5. Repeat the procedure (Steps 3 and 4) for the remaining cylinders.

If the measured value is less than the specified limit, refer to “Troubleshooting” in this Manual.

QUICK-ON START II SYSTEM (4JB1 / 4JB1T / 4JB1TC only)

Quick-On Start System Inspection Procedure

1. Disconnect the thermo-sensor connection on the thermostat outlet pipe.

2. Turn the starter switch to the “ON” position. If the Quick-On Start II System is operating properly,

the glow relay will make a clicking sound within 15 seconds after the starter switch is turned on.

3. Measure the glow plug terminal voltage with a circuit tester immediately after turning the starter switch to the “ON” position.

Glow Plug Terminal Voltage V

Approx. 11

0048-4.tif

00 – 50 SERVICE INFORMATION

0049-1.tif

0049-2.tif

QUICK-ON START III SYSTEM (4JG2 only)

Quick-On Start System Inspection Procedure

1. Disconnect the thermo-sensor connection on the thermostat outlet pipe.

2. Turn the starter switch to the “ON” position. If the Quick-On Start III System is operating properly,

the glow relay will make a clicking sound within seven seconds after the starter switch is turned on.

3. Measure the glow plug terminal voltage with a circuit tester immediately after turning the starter switch to the “ON” position.

Glow Plug Terminal Voltage V

NOTE:

Electrical power to the quick-on start system will be cut after the starter has remained in the “ON” position for twenty seconds.

Turn the starter switch to the “OFF” position and back to the “ON” position.

This will reset the Quick-On Start III System.

8 – 9

FIXING TORQUE

CYLINDER HEAD COVER, CYLINDER HEAD ROCKER, SHAFT BRAKER

SERVICE INFORMATION 00 – 51

N∙m (kg∙m/lb∙ft)

011LX002.tif

00 – 52 SERVICE INFORMATION

Crankshaft, Bearing Cap, Connecting Rod Bearing Cap, Crankshaft Damper Pulley, Flywheel, Oil Pan

N∙m (kg∙m/lb∙ft)

0051-1.tif

Timing Pulley Housing, Timing Pulley, Timing Gear, Camshaft Oil Seal Retainer

SERVICE INFORMATION 00 – 53

N∙m (kg∙m/lb∙ft)

014LX001.tif

00 – 54 SERVICE INFORMATION

Cooling System and Lubrication System

N∙m (kg∙m/lb∙ft)

SERVICE INFORMATION 00 – 55

Intake Manifold, Exhaust Manifold, Exhaust Pipe

N∙m (kg∙m/lb∙ft)

150LX004.tif

00 – 56 SERVICE INFORMATION

N∙m (kg∙m/lb∙ft)

036LX003.tif

SERVICE INFORMATION 00 – 57

Engine Electricals

N∙m (kg∙m/lb∙ft)

0056-1.tif

00 – 58 SERVICE INFORMATION

Engine Fuel

N∙m (kg∙m/lb∙ft)

0057-1.tif

SERVICE INFORMATION 00 – 59

Engine Mounting Bracket

N∙m (kg∙m/lb∙ft)

0058-1.tif

00 – 60 SERVICE INFORMATION

SPECIAL TOOLS

ILLUSTRATION TOOL NO. TOOL NAME

5-8840-2035-0 Crank Timing Pulley (4JG2 Belt Drive only)

5-8840-0200-0 Oil Filter Wrench (89.0 mm/3.5 in)

5-8840-0202-0 Oil Filter Wrench (106.0 mm/4.2 in)

5-8840-2209-0 Oil Filter Wrench (100.6 mm/4.0 in)

9-8523-1423-0 (J-29760) Valve Spring Compressor

5-8840-2033-0 Oil Seal Installer

5-8840-9018-0 Piston Ring Compressor

5-8840-2093-0 Tacho Meter

9-8523-1212-0 Valve Guide Replacer

5-8840-0086-0

Camshaft Timing Pulley Remover (4JG2 Belt Drive only)

5-8840-0199-0 Rubber Hardness Tester

SERVICE INFORMATION 00 – 61

SPECIAL TOOLS (CONT.1)

ILLUSTRATION TOOL NO. TOOL NAME

5-8840-2675-0 Compression gauge

5-8531-7001-0 Gauge Adapter

5-8531-7002-0 Gauge Adapter

5-8840-0145-0 Measuring Device

5-8522-0024-0

5-8840-0266-0 Angle Gauge

5-8840-9016-0 Injection Nozzle Tester

5-8840-2034-0 Nozzle Holder Remover (4JB1 only)

5-8840-2038-0 Camshaft Bearing Replacer

5-8840-2036-0

Crankshaft Timing Pulley Installer (4JG2 Belt Drive only)

Front Oil Seal Installer (4JB1, 4JG2, Gear Drive only)

00 – 62 SERVICE INFORMATION

SPECIAL TOOLS (CONT.2)

LLUSTRATION TOOL NO. TOOL NAME

5-8840-0259-0 Nozzle Holder Wrench (4JG2 only)

5-8840-0253-0 (J-22700) Fuel Filter Wrench

5-8840-2362-0 Front Oil Seal Remover (4JG2, Belt Drive only)

5-8840-2361-0 Front Oil Seal Installer (4JG2, Belt Drive only)

5-8840-2360-0 Rear Oil Seal Remover

5-8840-2359-0 Rear Oil Seal Installer

5-8840-2040-0 Cylinder Liner Installer (4JB1 only)

5-8840-2313-0 Cylinder Liner Installer (4JG2 only)

5-8840-2039-0 Cylinder Liner Remover (4JB1 only)

5-8840-2304-0 Cylinder Liner Remover Ankle (4JG2 only)

5-8840-2000-0 Pilot Bearing Remover

5-8840-0019-0 Sliding Hammer

5-8522-0024-0 Pilot Bearing Installer

SERVICE INFORMATION 00 – 63

MEMO

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

GENERAL ENGINE MECHANICAL 6A – 1

HOME

SECTION 6A

GENERAL ENGINE MECHANICAL

CONTENTS

PAGE

Cylinder Head................................................................................................................. 6A - 2

Valve Spring, Valve Guide Oil Seal, Valve Guide, Push Rod..................................... 6A - 10

Camshaft, Tappet........................................................................................................... 6A - 17

Rocker Arm Assembly................................................................................................... 6A - 24

Oil Pump......................................................................................................................... 6A - 27

Crankshaft......................................................................................................................6A -31

Piston and Connecting Rod .......................................................................................... 6A - 47

Cylinder Block................................................................................................................ 6A - 56

6A – 2 GENERAL ENGINE MECHANICAL

CYLINDER HEAD

Disassembly steps

1. Thermostat housing Assembly

2. Injection nozzle holder (4JG2) 2a. Injection nozzle holder (4JB1

4JB1TC)

3. Glow plug and plug connector (4JG2)

3a. Glow plug and plug connector

(4JB1・4JB1TC)

4. Rocker arm shaft and rocker arm

5. Push rod

6. Cylinder head

Reassembly steps

To reassemble, follow the disassembly steps in the reverse order.

・

(4JB1)

NOTE:

• During disassembly, be sure that the valve train components are kept together and identified so that they can be re-installed in their original locations.

• Before removing the cylinder hea d from the engine and before disassembling the valve mechanism, make a compression test and note the results.

DISASSEMBLY

1. Thermostat Housing Assembly

2. Injection Nozzle Holder (4JG2)

2a. Injection Nozzle Holder (4JB1, 4JB1TC)

1) Remove the nozzle holder bracket nuts.

6A-2-1.tif

6A-2-2.tif

6A-3-1.tif

GENERAL ENGINE MECHANICAL 6A – 3

2) Use the nozzle holder remover and the sliding

hammer to remove the nozzle holder together with the holder bracket.

Nozzle Holder Remover: 5-8840-2034-0 Sliding Hammer: 5-8840-0019-0

3. Glow Plug and Glow Plug Connector (4JG2)

3a. Glow Plug and Glow Plug Connector (4JB1,

4JB1TC)

4. Rocker Arm Shaft and Rocker Arm

5. Push Rod

6. Cylinder Head

• Loosen the cylinder head bolts a little at a time in

the numerical order shown in the illustration.

NOTE:

Failure to loosen the cylinder head bolts a little at a time in numerical order will adversely effect the cylinder head lower surface.

6A-3-2.tif

CLEAN

• Cylinder head bolts

• Cylinder head

Carefully remove all varnish, soot and carbon to the bare metal. Do not use a motorized wire brush on any gasket sealing surface.

INSPECTION AND REPAIR

Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during inspection.

• Cylinder head gasket and mating surfaces for leaks, corrosion and blow-by. If the gasket has failed, determine the cause;

- Improper installation

- Loose or warped cylinder head

- Insufficient torque on head bolts

- Warped case surface

1. Cylinder head bolts for damaged threads or stretching and damaged heads caused by improper use of tools.

CAUTION: Suspected bolts must be replaced.

2. Cylinder head for cracks, especially between valve seats and in the exhaust ports.

3. Cylinder head deck for corrosion, sand particles in head and porosity.

6A – 4 GENERAL ENGINE MECHANICAL

6A-4-1.tif

CAUTION: Do not attempt to weld the cylinder head. Replace it.

4. Cylinder head deck, intake and exhaust manifold mating surfaces for flatness.

These surfaces may be re-conditioned by milling (except cylinder head lower face). If the surfaces are “out of flat” by more than specification, the surface should be grinded to within specifications. If more than limit of specification, it should be replaced.

NOTE: The cylinder head lower face cannot be reground.

mm (in)

Standard Limit

6A-4-2.tif

6A-4-3.tif

Cylinder Head Lower Face Warpage

Cylinder Head Height

0.05 (0.002) or less

0.20 (0.0079)

92 (3.622) 91.55 (3.6043)

5. Water jacket sealing plugs seating surfaces.

6. Use a straight edge and a feeler gauge to measure the manifold cylinder head lifting face warpage. Regrind the exhaust manifold cylinder head lifting surfaces if the measured values are between the specified limit and the standard. If the measured values exceed the specified limit, the manifold must be replaced.

Exhaust Manifold Warpage mm (in)

Standard Limit

0.05 (0.002) or less 0.20 (0.0079)

Hot plug depression (4JG2 only)

1. Clean the cylinder head lower side, taking care not to damage the hot plug surfaces.

2. Use a straight edge and feeler gauge to measure hot plug depression in a straight line from the No. 1 hot plug to the No. 4 hot plug. If the measured value exceeds the limit, the hot plugs must be replaced.

Depression Limit mm (in)

0.02 (0.0008)

6A-4-4.tif

6A-5-1.tif

GENERAL ENGINE MECHANICAL 6A – 5

Hot plug removal (4JG2 only)

1. Insert a 3.0 - 5.0 (0.12 - 0.20.) diameter bar into the nozzle holder fitting hole unit it makes contact with the hot plug.

2. Lightly tap the bar with a hammer to drive the hot plug free.

If the measured value exceeds the limit, the hot plugs must be replaced.

Combustion chamber inspection (4JG2 only)

1. Remove the carbon adhering to the inside of the combustion chamber. Take care not to damage the hot plug fitting positions.

2. Inspect the inside of the combustion chamber, the hot plug, and the hot plug machined faces for cracking and other damage.

If cracking or damage is present, the cylinder head must be replaced.

NOTE: Be absolutely certain that there are no scratches or

protuberance on the combustion chamber surfaces which will be in contact with the hot plug after it is installed. There flaws will prevent the hot plug from seating correctly.

6A-5-2.tif

6A-5-3.tif

Hot plug inspection

Inspection the hot plugs for excessive wear and other damage. Replace the hot plugs if either of these conditions are discovered.

Hot plug installation (4JG2 only)

1. Align the hot plug knock ball ! with the cylinder head groove plastic hammer.

2. Place an appropriate metal plate # thick over the hot plug upper surface

3. Use a press % to exert a pressure of 44130 - 53937N (4500 - 5500 kg/9923 - 12128 lbs.) on the metal plate covering the hot plug upper surface. This will drive the hot plug into position.

4. Lightly tap the hot plug heads to make sure that they are firmly seated.

5. Repeat the procedure Steps 1-4 for the remaining hot

plugs.

"

and tap it temporarily into position with a

$

6A – 6 GENERAL ENGINE MECHANICAL

CAUTION: Do not apply pressure greater than that specified.

Damage to the cylinder head will result.

6. Use a surface grinder to grind off any hot plug surface protuberances.

The hot plug surfaces must be perfectly flush with the cylinder head.

7. After grinding, make sure that the hot plug surfaces are completely free of protuberances.

The hot plug surfaces must also be free of depressions.

Once again, lightly tap the hot plug heads to make sure that they are firmly seated.

6A-6-1.tif

6A-6-2.tif

6A-6-3.tif

Heat shield removal (4JG2 only)

After removing the hot plugs, use a hammer ! and a brass bar

#

and drive it free.

"

to lightly tap the lower side of the heat shield

Heat shield installation (4JG2 only)

Install the heat shield washer and the heat shield to the cylinder head from the nozzle holder installation hole side. Lightly tap the flange into place with a brass bar.

The heat shield flange side must be facing up.

NOTE: Always install a new heat shield. Never reuse the old

heat shield.

REASSEMBLY

6. Cylinder Head

1) Hot plug

• Set the nock ball in the positioning groove on the cylinder head side according to the order of the cylinders, and hit it lightly with a plastic hammer.

GENERAL ENGINE MECHANICAL 6A – 7

NOTE: After being pressed into the cylinder head, the hot plugs were provided with surface grinding. Accordingly, their dimensions are different individually among them, and take care not confuse the order of the cylinders.

When replacing the hot plug with new one:

When assembling a new hot plug, set the knock ball in the positioning groove on the cylinder side and hit it lightly with a plastic hammer until the hot plug is set in stably.

With patch attached to the hot plug to prevent it from being damaged, press it in with a force of 4.5 to 5.5 ton applied.

After pressing the hot plug, grind its surface to the cylinder head.

And finally, hit the hot plug lightly with a plastic hammer and check it for any excessive sinking, protrusion or backlash.

2) Valve Seat Insert Installation

!

1. Carefully place the attachment

(having a smaller

outside diameter than the valve seat insert) on the

"

valve seat insert

.

6A-7-1.tif

6A-7-2.tif

NOTE: The smooth side of the attachment must contact the

valve seat insert.

2. Use the bench press

#

to gradually apply pressure to the attachment and press the valve seat insert into place.

NOTE: Do not apply an excessive amount of pressure with

the bench press. Damage to the valve seat will result.

Measure the height of the valve guide upper end from the upper face of the cylinder head.

Valve Guide Upper End Height (H) (Reference) mm (in)

13 (0.51)

NOTE: If the valve guide has been removed, both the valve

and the valve guide must be replaced as a set.

6A – 8 GENERAL ENGINE MECHANICAL

6A-7-3.tif

6A-8-1.tif

3) Spring lower seat

4) Valve stem oil seal

• Install a new oil controller in the valve.

• Guide using special tool Oil seal installer: 5-8840-2003-0

5) Valve

• Apply engine oil to the outside of the valve stem before installing it.

6) Valve Spring

• Attach the valve spring to the upper spring seat.

CAUTION

• The painted area of the valve spring should be facing downward.

• Apply compressed air to cylinder from the glow plug hole to hold the valve in place.

• Install split collar by special tool.

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

6A-8-2.tif

7) Split Collar

• Use a spring compressor to push the valve spring into position.

• Install the spring seat split collar.

• Set the split collar by tapping lightly around the head of the collar with a rubber hammer.

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

5. Push Rod

4. Rocker Arm Shaft and Rocker Arm

• Tighten rocker arm shaft fixing bolts

54 (5.5/40)

N∙m (kg∙m/lb∙ft)

3a. Glow Plug and Glow Plug Connector (4JB1/4JB1T

only)

3. Glow Plug and Glow Plug Connector

• Tighten glow plugs

23 (2.3/17)

N∙m (kg∙m/lb∙ft)

6A-8-3.tif

040LX016.tif

GENERAL ENGINE MECHANICAL 6A – 9

2a. Injection Nozzle Holder (4JB1/4JB1T/4JB1TC only)

!

1) Install the injection nozzle gasket

and the O-ring

to the injection nozzle holder #. Be sure that the O-ring fits snugly in the injection

nozzle groove.

2) Apply engine oil to the cylinder head nozzle holder hole.

3) Install the nozzle holder together with the nozzle holder bracket

$

to the cylinder head.

37 (3.8/27)

N∙m (kg∙m/lb∙ft)

2. Injection Nozzle (4JG2 only)

• Lightly tighten the holder nut to suck extent that the nozzle holder can turn one word and one word.

• Set positioning confirmation drilled hole (ø2) within a nozzle turning angle of ±5° against the cylinder headside positioning boss.

• Apply a wrench as illustrated and tighten the holder nut to the specified torque using a special tool.

CAUTION

• After tightening the holder nut, make sure that the drilled hole makes ±5° or smaller with the cylinder head-side positioning boss.

• When mounting leak off pipe, injection nozzle and pipe, clean then with air so that dust may not enter.

"

6A-9-1.tif

Nozzle Fixing Torque N∙m (kg∙m/lb∙ft)

64 (6.5/47)

Wrench: Nozzle holder 5-8840-0259-0

1. Thermostat Housing Assembly

• Tighten thermostat housing assembly fixing bolt.

19 (1.9/14)

N∙m (kg∙m/lb∙ft)

6A – 10 GENERAL ENGINE MECHANICAL

VALVE SPRING, VALVE GUIDE OIL SEAL, VALVE GUIDE, PUSH ROD

6A-10-2.tif

6A-10-1.tif

DISASSEMBLY

1. Rocker Arm Assembly

2. Split Collar

Using special Tool, compress valve spring Valve spring compressor: 9-8523-1423-0 (J-29760)

3. Valve Spring

4. Valve

5. Valve Guide Oil Seal

6. Valve Guide

Valve Guide Replacer: 9-8523-1212-0

GENERAL ENGINE MECHANICAL 6A – 11

INSPECTION AND REPAIR

Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during inspection.

Valve spring

CAUTION: Visually inspect the valve springs and replace them if

damage or abnormal wear is evident.

1. Free height

• Measure the free height of the springs. The springs must be replaced if the height is below the specified limit.

6A-11-1.tif

6A-11-2.tif

Free Height mm (in)

Standard Limit

48.0 (1.891) 47.100 (1.8560)

2. Squareness

• Measure the valve spring squareness with a steel square.

• Replace the valve springs if the measured value exceeds the specified limit.

Limit mm (in)

1.7 (0.067)

3. Spring tension

• Use spring tester to compress the springs to the installed height. Measure the compressed spring tension.

Replace the springs if the measured tension is below the specified limit.

Tension N (kg/lb)

6A-11-3.tif

At installed height

38.9 mm (1.5 in)

Standard Limit

296.2 (30.2/66.6) 257.9 (26.3/57.9)

Valve Guide

CAUTION: Taking care not to damage the valve seat contact

surface, when removing carbon adhering to the valve head.

Carefully inspect the valve stem for scratching or abnormal wear. If these conditions are present, the valve and the valve guide must be replaced as a set.

6A – 12 GENERAL ENGINE MECHANICAL

1. Valve Guide Clearance

• Measure the valve stem diameter with a micrometer. If the valve stem diameter is less than the specified

limit, the valve and the valve guide must be replaced as a set.

mm (in)

Standard Limit

6A-12-1.tif

Diameter of Valve stem

Inlet

Exhaust

7.946 - 7.961

(0.3128 - 0.3134)

7.921 - 7.936

(0.3118 - 0.3124)

7.880

(0.310.2)

7.850

(0.3091)

• Measure the inside diameter of the valve guide with a micrometer.

• Subtract the measured outer diameter of the valve stem from the measured inner diameter of the valve guide. If the valve exceeds of the valve guide.

If the valve exceeds the specified limit, the valve and the valve guide must be replaced as a set.

Valve Guide Clearance mm (in)

Standard Limit

Inlet clearance

Exhaust clearance

0.039 - 0.069

(0.0015 - 0.0027)

0.064 - 0.096

(0.0025 - 0.0038)

0.200

(0.0079)

0.250

(0.0098)

6A-13-1.tif

6A-13-2.tif

GENERAL ENGINE MECHANICAL 6A – 13

Valve Guide Replacement

1. Using special tool, drive out the valve guide from the combustion chamber side.

Valve guide replacer: 9-8523-1212-0

2. Apply engine oil to the outside of the valve guide. Using special tool, drive in a new valve guide from

cylinder head upper face side, and check the valve guide height.

Valve guide replacer: 9-8523-1212-0 Height mm (in)

NOTE: If the valve guide has been removed, both the valve

and the valve guide must be replaced as a set.

13 (0.51)

6A-13-3.tif

Valve Thickness

1. Measure the valve thickness

2. If the measured value is less than the specified limit the valve and the valve guide must be replaced as a set.

Valve Thickness mm (in)

Standard Limit

4JB1 4JB1T 4JB1TC

4JG2

Contact surface angle on valve seat on valve

1. Measure contact surface angle on valve seat.

2. If the measured value exceeds the limit, replace valve guide and valve seat as a set.

Standard Degrees

Inlet 1.79 (0.0705)

1.5 (0.06)

Exhaust 1.83 (0.0720)

Inlet 1.41 (0.0555)

1.1 (0.043)

Exhaust 1.39 (0.0547)

45°

6A-13-4.tif

6A – 14 GENERAL ENGINE MECHANICAL

6A-14-1.tif

Valve depression

1. Install the valve (1) to the cylinder head (2).

2. Use a depth gauge or a straight edge with steel rule to measure the valve depression from the cylinder head lower surface.

If the measured value exceeds the specified limit, the valve seat insert must be replaced.

Valve Depression mm (in)

Standard Limit

4JB1 4JB1T 4JB1TC

4JG2

Inlet 0.73 (0.029) 1.28 (0.050)

Exhaust 0.70 (0.028) 1.20 (0.047)

Inlet

1.1 (0.043) 1.6 (0.063)

Exhaust

Valve Contact Width

1. Check the valve contact faces for roughness and unevenness. Make smooth the valve contact surfaces.

2. Measure the valve contact width. If the measured value exceeds the specified limit, the

valve seat insert must be replaced.

Contact Width mm (in)

Standard Limit

6A-14-2.tif

6A-14-3.tif

6A-14-4.tif

Inlet 1.7 (0.0670) 2.2 (0.0866)

Exhaust 2.0 (0.0788) 2.5 (0.0984)

Valve Seat Insert Replacement

Valve Seat Insert Removal

!

1. Arc weld the tire inside circumference seat insert

2. Allow the valve seat insert to cool for a few minutes. This will invite contraction and make removal of the

valve seat insert easier.

3. Use a screwdriver

Take care not to damage the cylinder head

4. Carefully remove carbon and other foreign material from the cylinder head insert bore.

Valve Seat Insert Installation

1. Carefully place the attachment outside diameter than the valve seat insert) on the valve seat insert

NOTE: The smooth side of the attachment must contact the

valve seat insert.

2. Use a bench press the attachment and press the valve seat insert into place.

"

.

#

to pry the valve seat insert free.

!

(having a smaller

"

.

#

to gradually apply pressure to

of the valve

$

.

6A-15-1.tif

6A-15-2.tif

GENERAL ENGINE MECHANICAL 6A – 15

NOTE: Do not apply an excessive amount of pressure with

the bench press. Damage to the valve seat insert will result.

Valve Seat Insert Correction

1. Remove the carbon from the valve seat insert surface.

2. Use a valve cutter (15°, 45°, and 75° blades) to minimize scratches and other rough areas, this will bring the contact width back to the standard value.

Remove only the scratches and rough areas. Do not cut away too much. Take care not to cut away unblemished area of the valve seat surface.

Valve Seat Angle degree

NOTE: Use an adjustable valve cutter pilot. Do not allow the valve cutter pilot to wobble inside the

valve guide.

3. Apply abrasive compound to the valve seat insert surface.

4. Insert the valve into the valve guide.

5. Turn the valve while tapping it to fit the valve seat

insert.

6. Check that the valve contract width is correct.

7. Check that the valve seat insert surface is in contact with the entire circumference of the valve.

45°

6A-15-3.tif

6A-15-4.tif

Push Rod Curvature

1. Lay the push rod on a surface plate.

2. Roll the push rod along the surface plate and measure the push rod curvature with a thickness gauge.

If the measure value exceeds the specified limit, the push rod must be replaced.

Push Rod Curvature Limit mm (in)

3. Visually inspect both ends of the push rod for excessive wear and damage. The push rod must be replaced if these conditions are discovered during inspection.

0.4 (0.0157) or less

6A – 16 GENERAL ENGINE MECHANICAL

6A-16-1.tif

REASSEMBLY

6. Valve Guide

• Apply engine oil to the outside of the valve guide. Using special tool, drive in a new valve guide from the

rocker arm shaft side. Valve guide replacer: 9-8523-1212-0

5. Valve Guide Oil Seal

• Using special tool, drive in a new oil seal Oil special tool, drive in a new oil seal Oil seal installer: 5-8840-2033-0

4. Valve

• Apply engine oil to the outside of the valve stem.

3. Valve Spring

• Attach the valve seat to the upper spring seat. The painted area of the valve spring should be facing downward.

6A-16-2.tif

6A-16-3.tif

6A-16-4.tif

2. Split Collar

• Use a spring compressor to push the valve spring into position.

• Install the spring seat split collar.

• Set the split collar by tapping lightly around the head of the collar with a rubber hammer.

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

1. Rocker Arm Assembly

54 (5.5/40)

N∙m (kg∙m/lb∙ft)

CAMSHAFT, TAPPET

GENERAL ENGINE MECHANICAL 6A – 17

6A-17-2.tif

DISASSEMBLY

1. Cylinder Head Assembly

2. Flywheel

3. Cylinder Block Rear Plate

4. Oil Pan Assembly

5. Oil Pump Assembly

6. Camshaft Timing Gear (Gear Drive Model)

• Remove the camshaft timing gear bolt from the camshaft.

NOTE: Hold the camshaft stationary to prevent the camshaft

from turning.

• Use the universal puller timing gear

• Universal Puller: 5-8521-0002-0

Remove the thrust plate

"

.

!

to pull out the camshaft

#

.

6A-17-1.tif

6A – 18 GENERAL ENGINE MECHANICAL

6A-18-1.tif

6a. Camshaft Timing Pulley (Belt Drive Model)

"

• Use the timing pulley puller

to remove the pulley.

Timing Pulley Puller: 5-8840-0086-0

• Remove the stopper bolt.

7. Camshaft Thrust Plate (Gear Drive Model) 7a. Camshaft Pulley Center (Belt Drive Model)

8. Camshaft

9. Tappet

INSPECTION AND REPAIR

Make the necessary adjustment, repairs, and part replacements if excessive wear or damage is discovered during inspection.

1. Measure the Camshaft Thrust Clearance

• Use a dial indicator to measure the camshaft end play. This must be done before removing the camshaft

gear. If the camshaft end play exceeds the specified limit,

the thrust plate must be replaced.

Camshaft End Play mm (in)

6A-18-2.tif

6A-18-3.tif

Standard Limit

0.08 (0.0031) 0.2 (0.0079)

2. Camshaft Journal Diameter

• Use a micrometer to measure each camshaft journal

!

diameter in two directions

and ". If the measured value is less than the specified limit, the camshaft must be replaced.

Journal Diameter mm (in)

Standard Limit

49.945 - 49.975 (1.9663 - 1.9675) 49.60 (1.9528)

3. Cam Height

• Measure the cam height

H

with a micrometer. If the measured value is less than the specified limit, the camshaft must be replaced.

Cam Height mm (in)

Standard Limit

42.02 (1.6543) 41.65 (1.6398)

6A-18-4.tif

6A-19-1.tif

GENERAL ENGINE MECHANICAL 6A – 19

4. Camshaft Run-Out

• Mount the camshaft on V-blocks.

• Measure the run-out with a dial indicator. If the measured value exceeds the specified limit, the

camshaft must be replaced.

Run-Out mm (in)

Standard Limit

0.02 (0.008) or less 0.10 (0.0039)

5. Camshaft and Camshaft Bearing Clearance

• Use an inside dial indicator to measure the camshaft bearing inside diameter.

Camshaft Bearing Inside Diameter mm (in)

Standard Limit

6A-19-2.tif

6A-19-3.tif

50.00 - 50.03

(1.9685 - 1.9696)

50.08 (1.9716)

Camshaft Bearing Clearance mm (in)

Standard Limit

0.025 - 0.085

(0.0010 - 0.0033)

0.12 (0.005)

• If the clearance between the camshaft bearing inside diameter and the journal exceeds the specified limit, the camshaft bearing must be replaced.

Camshaft Bearing Replacement

Camshaft Bearing Removal

1. Remove the cylinder body plug plate.

2. Use the bearing replacer to remove the camshaft bearing.

Bearing Replacer: 5-8840-2038-0

Camshaft Bearing Installation

1. Align the bearing oil holes with the cylinder body oil holes.

2. Use the replacer to install the camshaft bearing. Bearing Replacer: 5-8840-2038-0

6A-19-4.tif

6A – 20 GENERAL ENGINE MECHANICAL

6A-20-1.tif

TAPPET

Visually inspect the tappet camshaft contact surfaces for pitting, cracking, and other abnormal conditions. The tappet must be replaced if any of these conditions are present.

Refer to the illustration at the left.

!

Normal contact

"

Cracking

#

Pitting

$

Irregular contact

%

Irregular contact

NOTE: The tappet surfaces are spherical. Do not attempt to

grind them with an oil stone or similar tool in an effort to repair the tappet. If the tappet is damaged, it must be replaced.

Tappet Outside Diameter

1. Measure the tappet outside diameter with a micrometer. If the measured value is less than the specified limit, the tappet must be replaced.

Tappet Outside Diameter mm (in)

6A-20-2.tif

6A-20-3.tif

Standard Limit

12.97 - 12.99

12.95 (0.509)

(0.510 - 0.511)

2. Measure the inside diameter tappet on the cylinder block and calculate the clearance.

If the clearance exceeds the limit, replace tappet or/and cylinder block.

Tappet and Cylinder Body Clearance mm (in)

Standard Limit

0.03 (0.001) 0.10 (0.004)

REASSEMBLY

9. Tappet

1) Apply a coat of engine oil to the tappet 1 and the cylinder body tappet insert holes 2.

2) Locate the position mark applies at disassembly (if the tappet is to be reused).

NOTE: The tappet must be installed before the camshaft.

6A-20-4.tif

6A-21-1.tif

6A-21-2.tif

GENERAL ENGINE MECHANICAL 6A – 21

8. Camshaft

1) Apply a coat of engine oil to the camshaft and the camshaft bearings.

2) Install the camshaft to the cylinder body. Take care not damage the camshaft bearings.

7a. Camshaft Timing Pulley Center (Belt Drive Model)

• Apply engine oil to the oil seal lip portion of the oil seal retainer.

• Apply the recommended liquid gasket or its equivalent to the retainer.

• Install the oil seal retainer to the cylinder body.

• Tighten the retainer bolts to the specified torque.

Oil Seal Retainer Bolt Torque N∙m (kg∙m/lb∙ft)

19 (1.9/14)

6A-21-3.tif

6A-21-4.tif

• Align the camshaft timing pulley center with the camshaft key.

• Tighten the timing pulley bolts to the specified torque.

Timing Pulley Bolt Torque N∙m (kg∙m/lb∙in)

8 (0.8/69)

7. Camshaft Thrust Plate (Gear Drive Model)

Install the thrust plate to the cylinder body and tighten the thrust plate bolts to specified torque.

Thrust Plate Bolt Torque N∙m (kg∙m/lb∙ft)

18 (1.8/13)

6a. Camshaft Timing Pulley (Belt Drive Model)

• Prevent the camshaft from turning when tightening the timing center bolt.

• Tighten the timing pulley center bolt to the specified torque.

Center Bolt Torque N∙m (kg∙m/lb∙ft)

64 (6.5/47)

6A-21-5.tif

6A – 22 GENERAL ENGINE MECHANICAL

6A-22-1.tif

6. Camshaft Timing Gear (Gear Drive Model)

1) Install the camshaft timing gear to the camshaft. The timing gear mark (“Y-Y”) must be facing outward.

2) Tighten the timing gear to the specified torque

Timing Gear Bolt Torque N∙m (kg∙m/lb∙ft)

64 (6.5/47)

5. Oil Pump Assembly

4. Oil Pan Assembly

Above works refer to “OIL PUMP” Section in this manual.

3. Cylinder Block Rear Plate

• Tighten cylinder block rear plate fixing bolts to the specified torque.

Rear Plate Bolt Torque N∙m (kg∙m/lb∙ft)

82 (8.4/61)

6A-22-2.tif

2. Flywheel

• Apply engine oil to fixing bolts.

• Tighten the flywheel bolts to the specified torque in two steps using the Angular Tightening Method.

Follow the numerical order shown in the illustration.

Flywheel Bolt Torque N∙m (kg∙m/lb∙ft)

1st Step (Snug Torque) 2nd Step (Final Torque)

59 (6.0/43) 60° - 90°

1. Cylinder Head Assembly

1) Hot plug

• Set the nock ball in the positioning groove on the cylinder head side according to the order of the cylinders, and hit it lightly with a plastic hammer.

NOTE: After being pressed into the cylinder head, the hot

plugs were provided with surface grinding. Accordingly, their dimensions are different individually among them, and take care not confuse the order of the cylinders.

6A-23-1.tif

GENERAL ENGINE MECHANICAL 6A – 23

When replacing the hot plug with new one:

When assembling a new hot plug, set the knock ball in the positioning groove on the cylinder side and hit it lightly with a plastic hammer until the hot plug is set in stably.

With patch attached to the hot plug to prevent it from being damaged, press it in with a force of 4.5 ~ 5.5 ton applied.

2) Valve Seat Insert Installation

!

1. Carefully place the attachment

(having a smaller

outside diameter than the valve seat insert) on the

"

valve seat insert

.

NOTE: The smooth side of the attachment must contact the

valve seat insert.

2. Use the bench press

#

to gradually apply pressure to the attachment and press the valve seat insert into place.

NOTE: Do not apply an excessive amount of pressure with

the bench press. Damage to the valve seat insert will result.

Measure the height of the valve guide upper end from the upper face of the cylinder head.

Valve Guide Upper End Height (H) (Reference) mm (in)

13 (0.51)

6A-23-2.tif

NOTE: If the valve guide has been removed, both the valve

and the valve guide must be replaced as a set.

3) Spring Lower Seat

4) Valve Stem Oil Seal

5) Valve

6) Valve Spring

7) Split Collar Above works refer to “VALVE” Section in this manual.

6A – 24 GENERAL ENGINE MECHANICAL

ROCKER ARM ASSEMBLY

DISASSEMBLY

1. Rocker Arm Shaft Assembly

2. Rocker Arm Shaft Snap Ring

3. Rocker Arm

4. Rocker Arm Shaft Bracket

5. Rocker Arm

6. Rocker Arm Shaft Spring

7. Rocker Arm Shaft

INSPECTION AND REPAIR

Make the necessary adjustment, repairs, and part replacements if excessive wear or damage is discovered during inspection.

Use a micrometer to measure the rocker shaft outside diameter at the point where the rocker arm moves on the rocker shaft.

Replace the rocker shaft if the diameter exceeds the specified limit.

6A-24-1.tif

mm (in)

6A-24-2.tif

Standard Limit

18.98 - 19.00

(0.7472 - 0.7480)

18.9 (0.744)

GENERAL ENGINE MECHANICAL 6A – 25

Oil Clearance

1. Use either a vernier caliper or a dial indicator to measure the rocker arm inside diameter.

Rocker Arm Inside Diameter mm (in)

Standard Limit

6A-25-1.tif

19.036 - 19.060

(0.7494 - 0.7503)

19.100 (0.7519)

2. Measure the rocker arm shaft outside diameter. If the measured value exceeds the specified limit,

replace either the rocker arm or the rocker arm shaft.

Rocker Arm and Rocker Shaft Clearance mm (in)

Standard Limit

0.06 - 0.08

(0.0024 - 0.0031)

0.10 (0.0039)

3. Check that the rocker arm oil port is free is obstructions.

If necessary, use compressed air to clean the rocker arm oil port.

6A-25-2.tif

6A-25-3.tif

Rocker Arm Correction

Inspection the rocker arm valve stem contact surface for

!

step wear

and scoring ".

If the contact surfaces have light step wear or scoring, they may be honed with an oil stone.

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

6A – 26 GENERAL ENGINE MECHANICAL

6A-26-1.tif

Rocker Arm Shaft Run-Out

1. Place the rocker arm shaft on a V-block.

2. Use a dial indicator to measure the rocker arm shaft central portion run-out.

If the run-out is very slight, correct the rocker arm shaft run-out with a bench press. The rocker arm must be at cold condition.

If the measured rocker arm shaft run-out exceeds the specified limit, the rocker arm shaft must be replaced.

Rocker Arm Shaft Run-Out mm (in)

Limit

6A-26-2.tif

4JB1 / 4JB1T / 4JB1TC

0.2 (0.008)

4JG2

REASSEMBLY

7. Rocker Arm Shaft

• Apply a light coat of engine oil to the rocker arm shafts.

• Position the rocker arm shaft with the large oil hole (4ø) facing the front of the engine.

• Install the rocker shaft together with the rocker arm, the rocker arm shaft bracket, and the spring.

6. Rocker Arm Shaft Spring

5. Rocker Arm

4. Rocker Arm Shaft Bracket

3. Rocker Arm

2. Rocker Arm Shaft Snap Ring

1. Rocker Arm Shaft Assembly

• Install the rocker arm shaft assembly in cylinder head.

• Tighten the rocker arm shaft fixing bolts to the specified torque.

6A-26-3.tif

OIL PUMP

GENERAL ENGINE MECHANICAL 6A – 27

Disassembly steps

1. Vacuum pump oil hose

2. Stiffener and space rubber

3. Oil pan Assembly

4. Oil pump Assembly

5. Strainer

6. Pump cover

7. Driven gear

8. Oil pump body

6A-27-2.tif

DISASSEMBLY

1. Vacuum Pump Oil Hose

!

• Remove the oil hose

2. Stifner & Space Rubber

• Remove the stiffener from of the oil pan left & right side.

• Take out space rubber.

3. Oil Pan Assembly

from oil pan.

6A-27-1.tif

6A – 28 GENERAL ENGINE MECHANICAL

4. Oil Pump Assembly

5. Strainer

6. Pump Cover

7. Driven Gear

8. Oil Pump Body

INSPECTION AND REPAIR

Make the necessary adjustment, repairs, and part replacements if excessive wear or damage is discovered during inspection.

Body and gears

The pump assembly must be replaced if one or more of the conditions below is discovered during inspection.

• Badly worn or damaged driven gear guide.

• Badly worn or damaged gear teeth.

Gear Teeth and Body Inner Wall Clearance

• Use a feeler gauge to measure the clearance between the gear teeth and the body inner wall.

• If the clearance between the gear teeth and the body inner wall exceeds the specified limit, either the gear or the body must be replaced.

Gear Teeth and Body Internal Wall Clearance mm (in)

6A-28-1.tif

6A-28-2.tif

Standard Limit

0.14 (0.0055) 0.20 (0.0079)

Gear and Body Clearance

• Use a feeler gauge to measure the clearance between the body and the gear.

• If the clearance between the gear and the body exceeds the specified limit, the body must be replaced.

Gear and Body Clearance mm (in)

Standard Limit

0.06 (0.024) 0.15 (0.0059)

6A-29-1.tif

GENERAL ENGINE MECHANICAL 6A – 29

REASSEMBLY

8. Oil Pump Body

7. Driven Gear 6 Pump Cover

5. Strainer

• Install the strainer assembly and tighten the strainer assembly fixing bolts.

16 (1.6/12)

4. Oil Pump Assembly

• Apply molybdenum mixed engine oil to drive gear of camshaft and driven gear of oil pump.

• Tighten the oil pump fixing bolt to the specified torque.

19 (1.9/14)

N∙m (kg∙m/lb∙ft)

6A-29-2.tif

6A-29-3.tif

3. Oil Pan Assembly

• Apply the recommended liquid gasket or its equivalent to the No. 5 bearing cap arches, the grooves, the cylinder block and the timing gear case filting face at the positions shown in the illustration.

• Fit the gasket rear lipped portion into the No. 5 groove.

• Be absolutely sure that the lipped portion is fitted snugly into the groove.

• Install the oil pan to the cylinder body.

• Tighten the oil pan bolts to the specified torque.

Oil Pan Bolt Torque N∙m (kg∙m/lb∙ft)

19 (1.9/14)

6A – 30 GENERAL ENGINE MECHANICAL

2. Stiffener & Space Rubber

• Install the space rubber.

• Install the stiffener tighten to the specified torque.

Engine Body Side N∙m (kg∙m/lb∙ft)

Clutch Housing Side N∙m (kg∙m/lb∙ft)

37 (3.8/27)

78 (8.0/58)

1. Vacuum Pump Oil Hose

• Install the oil hose to oil pan.

CRANKSHAFT

5a

GENERAL ENGINE MECHANICAL 6A – 31

Disassembly steps

1. Cylinder head Assembly and gasket

2. Oil pan Assembly

3. Timing gear

3a. Timing Belt and Pulley

4. Front oil seal

5. Timing gear housing

5a. Timing pulley housing

6. Oil pump Assembly

7. Piston cooling oil pipe

8. Piston and connecting rod

9. Flywheel

10. Cylinder block rear plate

11. Crankshaft rear oil seal

12. Main bearing cap

13. Crankshaft

Reassembly steps

To reassemble, follow the disassembly steps in the reverse order.

DISASSEMBLY

1. Cylinder Head Assembly and Gasket

2. Oil Pan Ambly

3. Timing Gear (Gear Drive Model) 3a. Timing Belt and Pulley (Belt Drive Model)

4. Front Oil Seal

• With the oil seal pushed in deep, install the special tool as shown in the illustration to remove the oil seal.

Remover: 5-8840-2362-0

6A-31-1.tif

6A – 32 GENERAL ENGINE MECHANICAL

6A-32-1.tif

5. Timing Gear Housing 5a.Timing Pulley Housing

6. Oil Pump Assembly

7. Piston Cooling Oil Pipe

8. Piston and Connecting Rod

9. Flywheel

10. Cylinder Block Rear Plate

11. Crankshaft Rear Oil Seal (Gear and Belt Drive Model)

• With the oil seal pushed in deep, install the special tool as shown in the illustration to remove the oil seal.

Remover: Rear Oil Seal 5-8840-2360-0

NOTE: Take care not to damage sealing surface of rear plate

and crankshaft when removing oil seal.

12. Main Bearing Cap

13. Crankshaft

INSPECTION AND REPAIR

6A-32-2.tif

Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during inspection.

1. Crankshaft

Thrust clearance Set the dial indicator as shown in the illustration and

measure the crankshaft thrust clearance. If the thrust clearance exceeds the specified limit, replace

the thrust bearing as a set. Thrust clearance mm (in)

Standard Limit

0.10 (0.0039) 0.30 (0.0118)

6A-33-1.tif

6A-33-2.tif

6A-33-3.tif

GENERAL ENGINE MECHANICAL 6A – 33

2. Main bearing clearance

1) Remove the main bearing caps in the sequence shown in the illustration.

Arrange the removed main bearing caps in the cylinder number order.

2) Remove the crankshaft. Remove the main bearings.

3) Clean the upper and lower bearings as well as the crankshaft main journal.

4) Check the bearings for damage or excessive wear. The bearings must be replace as a set if damage or

excessive wear is discovered during inspection.

5) Set the upper bearings and the thrust washers to their original positions. Carefully install the crankshaft.

6) Set the lower bearings to the bearing cap original position.

7) Apply plastigage to the crankshaft journal unit as shown in the illustration.

8) Install the main bearing caps. Apply engine oil to the bolt threads and the seats. Tighten the bolts to the specified torque.

167 (17/123)

N∙m (kg∙m/lb∙ft)

NOTE: Do not allow the crankshaft to rotate.

9) Remove the main bearing caps.

10) Measure the plastigage width and determine the oil clearance. If the oil clearance exceeds the specified limit, replace the main bearings as a set and/or replace the crankshaft.

11) Clean the plastigage from the bearings and the crankshaft.

12) Remove the crankshaft and the bearings.

Oil Clearance mm (in)

4JB1 /4JB1T 4JB1TC

4JG2

Standard Limit

0.035 - 0.080

(0.0014 - 0.0036)

0.11 (0.0043)

0.031 - 0.063

(0.0012 - 0.0025)

Isuzu NHR 4J Series, NPR 4J Series, NKR 4J Series Workshop Manual

Specifications and Main Features

Frequently Asked Questions

User Manual