Isuzu A-4JA1, 4ja1, A-4JB1 Workshop Manual

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Page 1

INDUSTRIAL

DIESEL ENGINE

A-4JA1, A-4JB1

MODELS

2003 ISUZU MOTORS LIMITED

WORKSHOP MANUAL

Page 2

FOREWORD

This Workshop Manual is designed to help you perform necessary maintenance, service, and repair procedures on applicable Isuzu industrial engines.

Information contained in this Workshop Manual is the latest available at the time of publication.

Isuzu reserves the right to make changes at any time without prior notice.

This Workshop Manual is applicable to 1998 and later models.

NOTICE

Before using this Workshop Manual to assist you in performing engine service and maintenance operations, it is recommended that you carefully read and throughly understand the information contained in Section - 1 under the headings “General Repair Instruction” and “Notes on The Format of This Manual”

Page 3

TABLE OF CONTENTS

SECTION 1. GENERAL INFORMATION.................................. 1

SECTION 2. MAINTENANCE ............................................. 17

SECTION 3. ENGINE ASSEMBLY (1) .................................... 29

(DISASSEMBLY)

SECTION 4. ENGINE ASSEMBLY (2) .................................... 47

(INSPECTION AND REPAIR)

SECTION 5. ENGINE ASSEMBLY (3) .................................... 81

(REASSEMBLY)

SECTION 6. LUBRICATING SYSTEM.................................... 109

SECTION 7. COOLING SYSTEM ......................................... 121

SECTION 8. FUEL SYSTEM............................................... 133

SECTION 9. ENGINE ELECTRICALS ..................................... 147

SECTION 10. TROUBLESHOOTING....................................... 175

SECTION 11. SPECIAL TOOL LIST ........................................ 201

SECTION 12. REPAIR STANDARDS....................................... 205

SECTION 13. CONVERSION TABLE....................................... 219

Page 4

GENERAL INFORMATION

SECTION 1

GENERAL INFORMATION

TABLE OF CONTENTS

ITEM PAGE

General repair instructions ....................................................... 2

Notes on the format of this manual................................................. 2

Main data and specifications....................................................... 6

Tightening torque specifications ................................................... 7

Page 5

GENERAL INFORMATION

GENERAL REPAIR INSTRUCTIONS

1. Before performing any service operation with the engine mounted, disconnect the grounding cable from the battery.

This will reduce the chance of cable damage and burning due to short circuiting.

2. Always use the proper tool or tools for the job at hand. Where specified, use the specially designed tool or tools.

3. Use genuine ISUZU parts.

4. Never reuse cotter pins, gaskets, O-rings, lock washers, and self locking nuts. Discard them as you remove them. Replace them with new ones.

5. Always keep disassembled parts neatly in groups. This will ensure a smooth reassembly operation. It is especially important to keep fastening parts separate. These parts vary in hardness and design,

depending on their installation position.

6. All parts should be carefully cleaned before inspection or reassembly. Oil ports and other openings should be cleaned with compressed air to make sure that they are

completely free of obstructions.

7. Rotating and sliding part surfaces should be lubricated with oil or grease before reassembly.

8. If necessary, use a sealer on gaskets to prevent leakage.

9. Nut and bolt torque specifications should be carefully followed.

10. Always release the air pressure from any machine-mounted air tank(s) before dismounting the engine or disconnecting pipes and hoses. To not do so is extremely dangerous.

11. Always check and recheck your work. No service operation is complete until you have done this.

NOTES ON THE FORMAT OF THIS MANUAL

This Workshop Manual is applicable to ISUZU industrial engine or engines which is or are stated in the title.

When more than two engine models are dealt in the manual, such engines have common parts and components as well as data and specifications, unless otherwise specified.

1. Find the applicable section by referring to the Table of Contents at the beginning of the Manual.

2. Common technical data such as general maintenance items, service specifications, and tightening torques are included in the "General Information" section.

The section ENGINE ASSEMBLY is an exception. This parts are divided in three sections to facilitates indexing.

3. Each section is divided into sub-sections dealing with disassembly, inspection and repair, and reassembly.

Page 6

GENERAL INFORMATION

4. When the same servicing operation is applicable to several different units, the manual will direct you to the appropriate page.

5. For the sake of brevity, self-explanatory removal and installation procedures are omitted. More complex procedures are covered in detail.

6. Each service operation section in this Workshop Manual begins with an exploded view of the applicable area. A brief explanation of the notation used follows.

★

★Repair kit

★

Disassembly Steps - 2

1. Water by-pass hose

2. Thermostat housing

3. Water pump

▲ 4. Injection nozzle holder

5. Glow plug and glow plug connector

6. Cylinder head cover

▲ 7. Rocker arm shaft and rocker arm

8. Push rod

▲ 9. Cylinder head

10. Cylinder head gasket

▲ 11. Crankshaft damper pulley with

dust seal

12. Timing gear case cover

13. Timing gear cover

14. Timing gear oil pipe

15. Idler gear “B” and shaft

▲ 16. Idler gear “A”

17. Idler gear shaft

Inverted Engine

Parts marked with an asterisk (*) are included in the repair kit.

Parts within a square frame are to be removed and installed as a single unit, and their disassembly steps or reassembly steps are shown in the illustrations respectively.

The number tells you the service operation sequence.

Removal of unnumbered parts is unnecessary unless replacement is required.

The "* Repair Kit" indicates that a repair kit is available.

The parts listed under "Disassembly Steps" or "Reassembly Steps" are in the service operation sequence.

The removal or installation of parts marked with a triangle (▲) is an important operation. Detailed information is given in the text.

Page 7

GENERAL INFORMATION

8. The following symbols appear throughout this Workshop Manual. They tell you the type of service operation or step to perform.

.... Removal .... Adjustment

.... Installation .... Cleaning

.... Disassembly ... Important operation requiring extra care

.... Reassembly .... Specified torque (tighten)

.... Alignment (marks) ....

Special tool use required or recommended(Isuzu tool or tools)

.... Directional indication ....

Commercially available tool use required or recommended

.... Inspection .... Lubrication (oil)

.... Measurement .... Lubrication (grease)

.... Sealant application

7. Below is a sample of the text of the Workshop Manual.

4. Camshaft Timing Gear

1) Install the thrust plate 1 .

2) Apply engine oil to the bolt threads 2 .

3) Install the camshaft timing gear with the timing mark stamped side facing out.

Camshaft Timing Gear Bolt Torque kgf·m(lb.ft/N·m)

11.0 ± 1.0 (79.5 ± 7.2/107.8 ± 9.8)

1

2

13. Crankshaft Rear Oil Seal

1) Apply engine oil to the oil seal lip circumference and the oil seal outer circumference.

2) Use the oil seal installer to install the oil seal to the cylinder body.

Oil Seal Installer: 5-8840-0141-0

14. Flywheel Housing

1) Apply liquid gasket to the shaded area shown in the illustration.

2) Tighten the flywheel housing bolts to the specified torque a little at a time in the sequence shown in the illustration.

Flywheel Housing Bolt Torque kgf·m(lb.ft/N·m)

M10x1.25 (0.40x0.05) Bolt 5.6±1.0 (40.5±7.2/ 54.9±9.8) M12x1.25 (0.47x0.05) Bolt 10.5±1.0 (76.0±7.2/103.0±9.8) M12x1.75 (0.47x0.07) Bolt 9.8±1.0 (71.0±7.2/ 96.0±9.8)

This is the item shown in the illustration. It is marked with a triangle (▲) on the Major Components page.

Letters and numbers contained in a circle refer to the illustration.

Special tools are identified by the tool name and/or number.

The illustration shows how the special tool is to be used.

Symbols indicate the type of service operation or step to be performed. A detailed explanation of these symbols follows.

Service data and specifications are given in this table.

Page 8

GENERAL INFORMATION

9. Measurement criteria are defined by the terms "standard" and "limit". A measurement falling within the "standard" range indicates that the applicable part or parts are

serviceable. "Limit" should be thought of as an absolute value. A measurement which is outside the "limit" indicates that the applicable part or parts must be either

repaired or replaced.

10. Components and parts are listed in the singular form throughout the Manual.

11. Directions used in this Manual are as follows: Front The cooling fan side of the engine viewed from the flywheel. Right The right hand side viewed from the same position. Left The left hand side viewed from the same position. Rear The flywheel side of the engine. Cylinder numbers are counted from the front of the engine. The front most cylinder is No. 1 and rear most cylinder is the final cylinder number of the engine. The engine's direction of rotation is counterclockwise viewed from the flywheel.

Page 9

GENERAL INFORMATION

MAIN DATA AND SPECIFICATIONS

Engine Model

A-4JA1 A-4JB1 4JB1T

Item

Engine type Water cooled, four-cycle, in-line, overhead valve Combustion chamber type Direct injection Cylinder liner type Dry No. of cylinders - Bore x Stroke mm(in.) 4 - 93.0 x 92.0 4 - 93.0 x 102.0 4 - 93.0 x 102.0

(3.66 x 3.62) (3.66 x 4.02) (3.66 x 4.02) Total piston displacement lit(cid) 2.449 (152.4) 2.771 (169.0) 2.771 (169.0) Compression ratio (To 1) 18.4 18.2 18.2

*Engine dimensions mm(in.) 805 x 625 x 729 739 x 625 x 746 578 x 771 x 577

Length x Width x Height (31.7 x 24.6 x 28.7) (29.1 x 24.6 x 29.4) (22.8 x 30.4 x 22.7)

*Engine weight (Dry) kg(lb.) 218 (480) 220 (486) 245 (540)

Fuel injection order 1 – 3– 4 – 2

*Fuel injection timing (B.T.D.C.) degrees 14

Specified fuel Diesel fuel Injection pump In-line plunger, Bosch A type Bosch distributor

VE type

Governor Variable speed mechanical type

*Low idle speed rpm 850 – 1,000

Injection nozzle Multi-hole type Injection starting pressure kgf/cm2(psi/MPa) 185 (2630/18.1) Fuel filter type Cartridge papaer element Water sedimentor (if so equipped) Sediment/water level indicating type Compression pressure kgf/cm2(psi/MPa) 31 (441/3.04) Valve clearance (at cold) Intake mm(in.) 0.40 (0.0157)

Exhaust mm(in.) 0.40 (0.0157) Lubrication method Pressurized circulation Oil pump Trochoid type Main oil filter type Cartridge paper element, full flow Partial oil filter Not equipped

*Lubricating oil volume lit.(qts) 5.5 (5.8) – 6.6 (7.0) 4.6 (4.9) – 6.4 (6.8) 4.6 (4.9) – 6.3 (6.7)

Oil cooler (if so equipped) Water cooled built in oil filter Cooling method Pressurized forced circulation Coolant volume lit.(qts) 5.0 (5.3) Water pump Belt driven impeller type Thermostat type Wax pellet type

*Alternator V-A 12 – 35 *Starter V-kW 12 – 2.2

Specifications marked with an asterisk (*) will vary according to engine application.

Page 10

GENERAL INFORMATION

TIGHTENING TORQUE SPECIFICATIONS

The tightening torque values given in the table below are applicable to the bolts unless otherwise specified.

STANDARD BOLT kgf·m (lb.ft/N·m)

An asterisk (*) indicates that the bolts are used for female threaded parts that are made of soft materials such as casting. Those shown in parentheses in the strength class indicate the classification by the old standard.

M 6 × 1.0

M 8 × 1.25

M10 × 1.25

M12 × 1.25

M14 × 1.5

M16 × 1.5

M18 × 1.5

M20 × 1.5

M22 × 1.5

M24 × 2.0

*M10 × 1.5

*M12 × 1.5

*M14 × 2.0

*M16 × 2.0

0.4 – 0.8

(2.9 – 5.8/3.9 – 7.8)

0.8 – 1.8

(5.8

–

13.0/7.8– 17.7)

2.1 – 3.5

(15.2– 25.3/20.6– 34.3)

5.0

–

7.5

(36.2

–

54.2/49.0– 73.6)

7.8

–

11.7

(56.4

–

84.6/78.5– 114.7)

10.6

–

16.0

(76.7

–

115.7/103.0– 156.9)

15.4

–

23.0

(111.1

–

166.4/151.0– 225.6)

21.0

–

31.6

(151.9

–

228.6/205.9– 307.9)

25.6

–

42.2

(185.2

–

305.2/251.1– 413.8)

36.6

–

55.0

(264.7

–

397.8/358.9– 539.4)

2.0

–

3.4

(14.5

–

24.6/19.6– 32.4)

4.6

–

7.0

(33.3

–

50.6/45.1– 68.7)

7.3

–

10.9

(52.8

–

78.8/71.6– 106.9)

10.2

–

15.2

(73.8

–

110.0/100.0– 149.1)

0.5

–

1.0

(3.6

–

7.2/4.9– 9.8)

1.2

–

2.3

(8.7

–

16.6/11.8– 22.6)

2.8

–

4.7

(20.3

–

34.0/27.5– 46.1)

6.2

–

9.3

(44.8

–

67.3/60.8– 91.2)

9.5

–

14.2

(68.7

–

102.7/93.2– 139.3)

13.8

–

20.8

(99.8

–

150.4/135.3– 204.0)

19.9

–

29.9

(143.9

–

216.3/195.2– 391.3)

27.5

–

41.3

(198.9

–

298.7/269.7– 405.0)

37.0

–

55.5

(267.6

–

401.4/362.9– 544.3)

43.9

–

72.5

(317.5

–

523.9/430.5– 711.0)

2.8

–

4.6

(20.3

–

33.3/27.5– 45.1)

5.8

–

8.6

(42.0

–

62.2/56.9– 84.3)

9.0

–

13.4

(65.1

–

96.9/88.3– 131.4)

13.2

–

19.8

(95.5

–

143.2/129.5 – 194.2)

1.7

–

3.1

(12.3

–

22.4/16.7– 30.4)

3.8

–

6.4

(27.5

–

46.3/37.3– 62.8)

7.7

–

11.6

(55.7

–

83.9/75.5– 113.8)

11.6

–

17.4

(83.9

–

125.6/113.8– 170.6)

16.3

–

24.5

(118.9

–

177.2/159.9– 240.3)

23.4

–

35.2

(169.3

–

254.6/229.5– 345.2)

32.3

–

48.5

(233.6

–

350.8/316.8– 475.6)

43.3

–

64.9

(313.2

–

469.4/424.6– 636.5)

56.5

–

84.7

(408.7

–

612.6/554.1– 830.6)

3.7

–

6.1

(26.8

–

44.1/36.3– 59.8)

7.3

–

10.9

(52.8

–

78.8/71.6– 106.9)

10.9

–

16.3

(78.8

–

118.9/106.9– 159.9)

15.6

–

23.4

(112.8

–

169.3/162.8– 229.5)

Refined

No mark

Non-Refined

4.8 (4T)

8.8(7T)

9.8 (9T)

Strength

Class

Bolt Identification

Bolt Diameter × pitch (mm)

Page 11

GENERAL INFORMATION

TIGHTENING TORQUE SPECIFICATIONS

The tightening torque values given in the table below are applicable to the bolts unless otherwise specified.

FLANGED HEAD BOLT kgf·m (lb.ft/N·m)

M 6 × 1

0.5– 0.9 0.6 – 1.2

(3.61– 6.50/4.6

–

8.5 (4.33 – 8.67/5.88 – 11.76)

M 8 × 1.25

1.1

–

2.0 1.4

–

2.9 1.9– 3.4

(7.95– 14.46/10.78– 19.61) (4.33– 8.67/5.88– 11.76) (13.74– 24.59/18.63– 33.34)

M10 × 1.25

2.3

–

3.9 3.6– 6.4 4.3– 7.2

(17.35– 28.20/23.53– 38.24) (26.03– 44.12/35.30– 59.82) (31.10– 52.07/42.16– 70.60)

*M10 × 1.5

2.3

–

3.8 3.5– 5.8 4.1– 6.8

(16.63

–

27.48/22.55– 37.26) (25.31– 41.95/34.32– 56.87) (29.65– 49.18/40.20– 66.68)

M12 × 1.25

5.6– 8.4 7.9– 11.9 8.7– 13.0

(40.50

–

60.75/54.91– 82.37) (57.14– 86.07/77.47– 116.69) (62.92– 94.02/85.31– 127.48)

*M12 × 1.75

3.5

–

9.5 7.3– 10.9 8.1– 12.2

(37.61– 56.41/50.99– 76.49) (52.80– 78.83/71.58– 106.89) (58.58– 88.24/79.43– 119.64)

M14 × 1.5

8.5

–

12.7 11.7– 17.6 12.6– 18.9

(61.48

–

91.85/83.35– 124.54) (84.62– 127.30/114.73– 172.59) (91.13– 136.70/123.56– 185.34)

*M14 × 2

7.6– 11.5 11.1– 16.6 11.8– 17.7

(57.14

–

85.34/77.47– 115.71) (80.28– 120.06/108.85– 162.79) (85.34– 128.02/115.71– 173.57)

M16 × 1.5

11.8– 17.7 17.1

–

26.5 18.0

–

27.1

(85.34

–

128.02/115.71– 173.57) (125.85– 189.50/170.63– 256.93) (130.19– 196.01/176.52– 265.76)

*M16 × 2

11.2– 16.7 16.6– 24.9 17.2– 25.7

(81.00

–

120.79/109.83

–

163.77) (120.06

–

180.10/162.79– 244.18) (124.40– 186.61/168.67– 253.01)

A bolt with an asterisk (*) is used for female screws of soft material such as cast iron.

Bolt head

marking

Nominal size (dia. x pitch)

Page 12

GENERAL INFORMATION

SPECIAL PARTS FIXING NUTS AND BOLTS

Cylinder Head Cover, Cylinder Head, and Rocker Arm Shaft Bracket

kgf·m(lb.ft./N·m)

1.0 – 2.0

(7.2 – 14.4/9.8 – 19.6)

0.8 – 1.8

(5.8 – 13.0/7.8 – 17.6)

1st Step 2nd Step

3.0 – 5.0

(21.7 – 36.1/29.4 – 49.0)

8.2 – 9.2

(59.4 – 66.5/80.4 – 90.2)

8.0 – 9.0

(57.9 – 65.1/78.4 – 88.2)

10.0 – 11.0

(72.4 – 79.6/98.1 – 107.9)

5.0 – 6.0

(36.2 – 43.4/49.0 – 58.8)

New bolt

Reused bolt

Page 13

GENERAL INFORMATION

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

kgf·m(lb.ft./N·m)

8.0 – 9.0

(57.9 – 65.1/78.4 – 88.2)

16.0 – 18.0

(115.7 – 130.2/159.6 – 176.5)

20.1 – 24.5

(145.4 – 177.2/197.1 – 240.3)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

11.5 – 12.5

(83.2 – 90.4/112.8 – 122.6)

14 – 24

(1.4 – 2.4/4.4 – 7.2)

Page 14

GENERAL INFORMATION

Timing Gear Case, Flywheel Housing, Camshaft, and Timing Gear

kgf·m(lb.ft./N·m)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

10.0 – 12.0

(72.4 – 86.8/98.1 – 117.7)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.0 – 1.5

(7.2 – 10.9/9.8 – 14.7)

6.6 – 8.7

(48 – 63/66 – 85)

M10 x 1.25 (0.39 x 0.05) 4.6 – 6.6 (33.3 – 47.7/45.1 – 64.7)

9.6 – 11.6 (69.4 – 83.9/94.1 – 113.8)

8.8 – 10.8 (63.7 – 78.1/86.3 – 105.9)

M12 x 1.25 (0.47 x 0.05) M12 x 1.75 (0.47 x 0.07)

Page 15

GENERAL INFORMATION

Cooling and Lubricating System

kgf·m(lb.ft./N·m)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

Page 16

GENERAL INFORMATION

Intake and Exhaust Manifold

kgf·m(lb.ft./N·m)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

Page 17

GENERAL INFORMATION

Engine Electrical

kgf·m(lb.ft./N·m)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

3.6 – 4.6

(26.0 – 33.3/35.3 – 45.1)

2.0 – 2.5

(14.4 – 18.1/19.6 – 24.5)

6.0 – 8.0

(43.4 – 57.9/58.8 – 78.4)

Page 18

GENERAL INFORMATION

Fuel Injection System

kgf·m(lb.ft./N·m)

3.2 – 4.4

(23.1 – 31.8/31.4 – 43.2)

20 – 4.0

(14.4 – 28.9/19.6 – 39.2)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

Page 19

MEMO

Page 20

MAINTENANCE

SECTION 2

MAINTENANCE

TABLE OF CONTENTS

ITEM PAGE

Model identification ............................................................. 18

Injection pump identification ...................................................... 18

Lubricating system .............................................................. 18

Fuel system .................................................................... 19

Cooling system ................................................................. 22

Valve clearance adjustment ....................................................... 23

Injection timing ................................................................. 24

Compression pressure measurement ............................................... 26

Recommended lubricants ......................................................... 27

Engine repair kit ................................................................ 28

Page 21

MAINTENANCE

Servicing refers to general maintenance procedures to be performed by qualified service personnel. Maintenance interval such as fuel or oil filter changes should be refered to “INSTRUCTION MANUAL”.

MODEL IDENTIFICATION

Engine Serial Number

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

INJECTION PUMP IDENTIFICATION

Injection volume should be adjusted after referring to the adjustment data applicable to the injection pump installed.

The injection pump identification number (A) is stamped on the injection pump identifications plate.

Note:

Always check the identification number before beginning a service operation.

Applicable service data will vary according to the identification number. Use of the wrong service data will result in reduced engine performance and engine damage.

1 ZEXEL (Manufacturer of the injection pump) identifi-

cation number

2 ISUZU Parts Number

Pump No. . . . . . . . . . . . . . .

NP - PE . . . . . . . . . . . . . . . . . . . . . .

(LICENCE BOSCH)

…Identification number

In-line type

LUBRICATING SYSTEM

Main Oil Filter Replacement Procedure

1. Loosen the drain plug to drain the engine oil.

2. Wait a few minutes and then retighten the drain plug.

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

Filter Wrench

Distributor type

Page 22

MAINTENANCE

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

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

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

7. Use a filter wrench to turn in the filter an additional 1 and 1/4 of a turn.

Filter Wrench

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

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

FUEL SYSTEM

Fuel Filter Replacement Procedure

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

Filter Wrench

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

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

4. Supply fuel to the new fuel filter to facilitate bleeding.

5. Turn in the new fuel filter until the filter O-ring is fitted against the sealing face.

Be very careful to avoid fuel spillage.

6. Use a filter wrench to turn in the fuel filter an additional 1/3 to 2/3 of a turn.

Page 23

MAINTENANCE

Water Separator (Water Sedimentor) (Optional Equipment)

Check the water separator float 1 level. If the float 1 has reached level 2 , loosen the drain plug 3 (at the bottom side of the water separator) to drain the water.

Drain Plug Torque kgf·m(lb.ft./N·m)

0.9 – 1.5 (6.5 – 10.9/8.8 – 14.7)

1

2

3

Air Bleeding

1. For the engine equipped with in-line type injection pump

1) Loosen the priming pump cap 1 on the injection pump.

2) Loosen the fuel return eye bolt 2 on the fuel filter.

3) Operate the priming pump until there are no more bubbles visible in the fuel being discharged from the fuel return eye bolt on the fuel filter.

4) Retighten the fuel return eye bolt on the fuel filter.

5) Loosen the bleeder bolt 3 while operating the injection pump priming pump to check that the air has been bled completely.

6) Operate the priming pump several times to check for fuel leakage around the injection pump and the fuel filter.

2. For the engine equipped with distributor type injection pump

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.

080ES004

Air bleeding screw

Page 24

MAINTENANCE

Injection Nozzle Injection Nozzle Inspection

Use a nozzle tester to check the injection nozzle opening pressure and the spray condition.

If the opening pressure is above or below the specified value, the injection nozzle must be replaced or reconditioned.

If the spray condition is bad, the injection nozzle must be replaced or reconditioned.

Injection Nozzle Opening Pressure kgf/cm2(psi/MPa)

185 (2,630/18.1)

Spray Condition

(1) Correct (2) Incorrect (Restrictions in orifice) (3) Incorrect (Dripping)

Injection Nozzle Adjustment

1. Clamp the injection nozzle in a vise.

2. Use a wrench to remove the injection nozzle retaining nut.

3. Install the injection nozzle 1 , the push rod 2 , the spring 3 , and adjusting shim 4.

Retaining Nut Torque kgf·m(lb.ft./N·m)

4.0 – 5.0 (28.9 – 36.2/39.2 – 49.0)

4. Attach the injection nozzle holder to the injection nozzle tester.

5. Apply pressure to the nozzle tester to check that the injection nozzle opens at the specified pressure.

If the injection nozzle does not open at the specified pressure, install or remove the appropriate number of adjusting shims to adjust it.

Adjusting Shim Availability mm(in.)

Range 0.50 – 1.50 (0.02 – 0.06) Increment 0.025 (0.001)

Total No. of Shims 40

(Reference) Removing or installing one shim will increase or

decrease the nozzle opening pressure approximately

3.77 kgf/cm2(53.6 psi/370kPa).

WARNING:

TEST FLUID FROM THE INJECTION NOZZLE TESTER WILL SPRAY OUT UNDER GREAT PRESSURE. IT CAN EASILY PUNCTURE A PERSON’S SKIN. KEEP YOUR HANDS AWAY FROM THE INJECTION NOZZLE TESTER AT ALL TIMES.

1

2 3

1

2

3

4

Page 25

MAINTENANCE

COOLING SYSTEM

Cooling Fan Drive Belt

Fan belt tension is adjusted by moving the alternator.

A Crankshaft damper pulley B Alternator pulley C Cooling fan drive pulley D Depress the drive belt mid-portion with a 10 kgf (22

lb/98 N) force.

Drive Belt Deflection mm(in.)

10.0 (0.39)

Thermostat Operating Test

1. Completely submerge the thermostat in water.

2. Heat the water. Stir the water constantly to avoid direct heat being

applied to the thermostat.

3. Check the thermostat initial opening temperature.

Thermostat Initial Opening Temperature °C(°F)

82 (180)

4. Check the thermostat full opening temperature.

Thermostat Full Opening Temperature °C(°F)

95 (203)

Valve Lift at Fully Open Position mm(in.)

8.0 (0.315)

1 Thermostat 2 Agitating Rod 3 Wooden Piece

1

2

3

Page 26

MAINTENANCE

VALVE CLEARANCE ADJUSTMENT

1. Retighten the rocker arm shaft bracket bolts in sequence as shown in the illustration.

Rocker Arm Shaft Bracket Bolt Torque kgf·m(lb.ft/N·m)

5.0 – 6.0 (36.2 – 43.4/49.0 – 58.8)

3124

2. 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.

TDC

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.

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

Valve Clearance mm(in.)

0.40 (0.016)

Loosen each valve clearance adjusting screw as shown in the illustration. (At TDC on the compression stroke of the No. 1 cylinder)

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

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

5. Tighten the lock nut securely.

Page 27

MAINTENANCE

Rotate the crankshaft 360°. Realign the crankshaft damper pulley TDC line with the

timing pointer. Adjust the clearances for the remaining valves as shown

in the illustration. (At TDC on the compression stroke of the No. 4 stroke)

INJECTION TIMING

Injection Timing Confirmation Procedure

1. In-line type injection pump

1) Rotate the crankshaft clockwise to align the cam shaft gear timing mark “O” with the timing gear case cover pointer.

The No. 1 cylinder will now be at the point where nearly injection timing.

2) Remove the No. 1 fuel injection pipe.

3) Remove the delivery valve holder 1 , the delivery valve spring 2 , and the delivery valve 3 .

4) Tighten the delivery valve holder to the specified torque.

Delivery Valve Holder Torque kgf·m(lb.ft/N·m)

4.0 – 4.5 (28.9 – 32.5/39.2 – 44.1)

1

2

3

5) Operate the injection pump priming pump while slowly rotating the crankshaft until fuel stops flowing from the delivery valve holder.

6) Conform that the crankshaft damper pulley notched line is aligned with the timing gear case cover pointer.

Injection Timing (Static BTDC)

14°

TDC 17

7) Remove the delivery valve holder.

8) Install the delivery valve 1 , the delivery valve spring 2 , and the delivery valve holder 3 .

9) Tighten the delivery valve holder to the specified torque.

10) Install the fuel injection pipes and tighten them to the specified torque.

Fuel Injection Pipe Torque kgf·m(lb.ft/N·m)

2.0 – 4.0 (14.4 – 28.9/19.6 – 39.2)

11) Operation to air breeding.

1

2

3

Page 28

MAINTENANCE

2. Distributor type injection pump

1) Rotate the crankshaft clockwise to align the cam shaft gear timing mark “O” with the timing gear case cover pointer.

The No. 1 cylinder will now be at the point where nearly injection timing.

2) Remove injector pump distributor head plug.

3) Fit a dial gauge and set lift to 1 mm (0.039 in).

4) Set crankshaft damper pulley Top Dead Center mark about 45° before Top Dead Center from the pointer.

5) Set dial gauge in the “0” position. Measuring device: 5-8840-0145-0

6) Turn the crankshaft a little rightwise and leftwise and see if the pointer is stable in the “0” position.

7) Turn the crankshaft in the normal direction and read the measuring device’s indication at TDC.

Starting Timing mm(in.)

0.5 (0.02)

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

9) Loosen the injection pump fixing nuts and bracket bolts.

10) Adjust the injection pump setting angle.

• If injection timing will be advanced, move the

injection pump away from the engine.

• If injection timing will be retarded, move the

injection pump toward the engine.

Tighten the pump fixing nut, adjust bolt and pump distribution head plug to the specified torque.

Pump Fixing Bolt kgf·m(lb.ft/N·m)

1.9 (13.7/18.6)

Injection Pump Distributor Head Plug kgf·m(lb.ft/N·m)

1.7 (12.3/16.7)

080ES002

080ES003

Page 29

MAINTENANCE

4. Set a compression gauge to the No. 1 cylinder glow plug hole.

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

Compression Pressure kgf/cm2(psi/MPa) at 200 rpm

Standard Limit

31 (441/3.04) 22 (313/2.157)

COMPRESSION PRESSURE MEASUREMENT

1. Start the engine and allow it to run for several minutes to warm it up.

2. Stop the engine and cut the fuel supply.

3. Remove all of the glow plugs from the engine.

Compression Gauge :5-8840-2675-0 Adapter :5-8840-9029-0

Page 30

MAINTENANCE

RECOMMENDED LUBRICANTS

ENGINE TYPE TYPES OF LUBRICANTS

Diesel engine oil

Without turbocharger

CC or CD grade

Diesel engine oil

With turbocharger

CD grade

ENGINE OIL VISCOSITY CHART

ENGINE OIL VISCOSITY GRADE – AMBIENT TEMPERATURE

[Single grade]

–0°C

(32°F)

15°C

(59°F)

25°C

(77°F)

30°C

(86°F)

–15°C

(5°F)

–30°C

(–22°F)

[Multi grade]

SAE 40

SAE 20, 20W

SAE 10W–30

SAE 15W–40, 20W–40

SAE 30

Ambient Temperature

SAE 10W

Page 31

MAINTENANCE

ENGINE REPAIR KIT

All of the numbered parts listed below are included in the Engine Repair Kit. The gaskets marked with an asterisk (*) are also included in the Top Overhaul Kit.

* 1. Cylinder head gasket * 2. Cylinder head cover gasket * 3. Head cover cap nut gasket

4. Drain cock gasket

5. Crankshaft rear oil seal

6. Gear case gasket

7. Gear case cover gasket

8. Oil pan drain plug gasket

9. Oil pan gasket

10. Oil filter gasket

11. Water pump gasket

12. Water outlet pipe gasket * 13. Thermostat housing gasket * 14. Intake manifold gasket * 15. Exhaust manifold gasket

16. Crankshaft front oil seal * 17. Nozzle holder O-ring * 18. Nozzle holder gasket

19. Joint bolt gasket

20. Vacuum pump pipe gasket

Page 32

ENGINE ASSEMBLY ( 1 )

SECTION 3

ENGINE ASSEMBLY ( 1 )

TABLE OF CONTENTS

ITEM PAGE

General description .............................................................. 30

Disassembly .................................................................... 31

Page 33

ENGINE ASSEMBLY ( 1 )

ENGINE ASSEMBLY

GENERAL DESCRIPTION

This illustration is based on the A-4JA1 engine.

The A-4J Series of industrial engines features the unique ISUZU troidal square combustion chamber. This design provides superior fuel economy for a wide range.

Auto-thermatic pistons with cast steel struts are used to reduce thermal expansion and resulting engine noise when the engine is cold.

Chrome plated dry type cylinder liners provide the highest durability. The laminated steel sheet cylinder head gasket is very durable. This type of gasket eliminates cylinder head bolt retightening. The tufftrided crankshaft has a long service life. Because it is tufftrided, it cannot be reground. The crankshaft main bearings and the connecting rod bearings are aluminum plated. These bearings are

especially sensitive to foreign material such as metal scraps. It is very important that the oil ports and other related parts be kept clean and free of foreign material.

Page 34

ENGINE ASSEMBLY ( 1 )

DISASSEMBLY

These disassembly steps are based on the A-4JA1 engine.

Disassembly Steps - 1

1. Cooling fan and spacer

2. Cooling fan drive belt

3. Cooling fan drive pulley

4. Alternator and adjusting plate

5. Fuel pipe (Fuel filter to injection pump)

6. Fuel pipe (Fuel filter to feed pump)

7. Fuel pipe (Fuel filter leak off)

8. Fuel filter

9. Oil pipe (Injection pump to cylinder body)

10. Rear engine hanger

11. Fuel leak off pipe

▲ 12. Fuel injection pipe with clip ▲ 13. Injection pump

14. Intake manifold

15. Starter

16. Oil filter

17. Oil pressure switch

18. Cooling water rubber hose

19. Cooling water intake pipe

20. Front engine hanger

▲ 21. Exhaust manifold

21 20 18 3 7 8 5 13 14 12

16 17 19 4 2 1 6 9 15

Page 35

ENGINE ASSEMBLY ( 1 )

Important Operations (Disassembly Steps - 1)

12. Fuel Injection Pipe with Clip

1) Loosen the injection pipe sleeve nuts at the delivery valve side.

Do not apply excessive force to the injection pipes.

2) Loosen the injection pipe clips.

3) Remove the injection pipes.

13. Injection Pump

1) Remove the six injection pump bracket bolts from the cylinder body timing gear case.

2) Remove the injection pump rear bracket bolts from the rear bracket.

3) Pull the injection pump with the injection pump timing gear free from the rear.

Note:

Plug the injection pump delivery holder ports with the shipping caps (or the equivalent) to prevent the entry of foreign material.

21. Exhaust Manifold

Loosen the exhaust manifold bolts a little at a time in the numerical order shown in the illustration.

4851

2673

Page 36

ENGINE ASSEMBLY ( 1 )

★

★Repair kit

★

Disassembly Steps - 2

1. Water by-pass hose

2. Thermostat housing

3. Water pump

▲ 4. Injection nozzle holder

5. Glow plug and glow plug connector

6. Cylinder head cover

▲ 7. Rocker arm shaft and rocker arm

8. Push rod

▲ 9. Cylinder head

10. Cylinder head gasket

▲ 11. Crankshaft damper pulley with

dust seal

12. Timing gear case cover

13. Timing gear cover

14. Timing gear oil pipe

15. Idler gear “B” and shaft

▲ 16. Idler gear “A”

17. Idler gear shaft Inverted Engine

Page 37

ENGINE ASSEMBLY ( 1 )

★

★Repair kit

Disassembly Steps - 3

1. Oil pan 1a. Oil pan (If so crankcase equipped)

2. Crankcase (If so equipped)

▲ 3. Flywheel

3a. Rear flywheel (If so equipped)

4. Flywheel housing

5. Oil pump with oil pipe

▲ 6. Camshaft with camshaft timing

gear and thrust plate

7. Timing gear case

▲ 8. Connecting rod cap with

lower bearing

▲ 9. Piston and connecting rod with

upper bearing

▲ 10. Crankshaft bearing cap with

lower bearing

11. Crankshaft thrust bearing

12. Crankshaft with crankshaft timing gear

▲ 13. Crankshaft upper bearing ▲ 14. Tappet

15. Crankshaft rear oil seal

16. Cylinder body

Page 38

ENGINE ASSEMBLY ( 1 )

Important Operations (Disassembly Steps - 2)

4. Injection Nozzle Holder

1) Remove the nozzle holder bracket nuts.

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 Humme: 5-8840-0019-0

7. Rocker Arm Shaft and Rocker Arm

Loosen the rocker arm shaft bracket bolts in numerical order a little at a time.

Note:

Failure to loosen the rocker arm shaft bracket bolts in numerical order a little at a time will adversely effect the rocker arm shaft.

1342

9. Cylinder Head

Loosen the cylinder head bolts in numerical order a little at a time.

Note:

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

1213

Page 39

ENGINE ASSEMBLY ( 1 )

11. Crankshaft Damper Pulley with Dust Seal

1) Block the flywheel with a piece of wood to prevent it from turning.

2) Use the damper pulley remover to remove the damper pulley.

Damper Pulley Remover

16. Idler Gear “A”

Measure the camshaft timing gear backlash, the crankshaft timing gear backlash, and the idler gear “A” end play before removing the idler gear “A” and shaft.

Timing Gear Backlash Measurement

1) Set a dial indicator to the timing gear to be measured.

Hold both the gear to be checked and the adjoining gear stationary.

2) Move the gear to be checked as far as possible to both the right and the left.

Take the dial indicator reading. If the measured value exceeds the specified limit,

the timing gear must be replaced.

Timing Gear Backlash mm(in.)

Standard Limit

0.10–0.17 (0.0039–0.0067) 0.30 (0.012)

Idler Gear “A” End Play Measurement

Insert a feeler gauge between the idler gear and the thrust collar to measure the gap and determine the idler gear end play.

If the measured value exceeds the specified limit, the thrust collar must be replaced.

Idler Gear End Play mm(in.)

Standard Limit

0.07 (0.0028) 0.30 (0.012)

Page 40

ENGINE ASSEMBLY ( 1 )

Important Operations (Disassembly Steps - 3)

3. Flywheel

1) Block the flywheel with a piece of wood to prevent it from turning.

2) Loosen the flywheel bolts a little at a time in the numerical order shown in the illustration.

6. Camshaft with Camshaft Timing Gear and Thrust Plate

1) Remove the thrust plate bolts.

2) Pull the camshaft free along with the camshaft

timing gear and the thrust plate.

Note:

Be careful not to damage the camshaft journal, the cam, and the camshaft during the disassembly procedure.

8. Connecting Rod Cap with Lower Bearing

If the connecting rod lower bearings are to be reinstalled, mark their fitting positions by tagging each bearing with the cylinder number from which it was removed.

9. Piston and Connecting Rod with Upper Bearing

1) Remove carbon deposits from the upper portion

of the cylinder wall with a scraper before removing the piston and connecting rod.

2) Move the piston to the top of the cylinder and

tap it with a hammer grip or similar object from the connecting rod lower side to drive it out.

If the connecting rod upper bearings are to be reinstalled, mark their fitting positions by tagging each bearing with the cylinder number from which it was removed.

Page 41

ENGINE ASSEMBLY ( 1 )

10. Crankshaft Bearing Cap with Lower Bearing

1) Measure the crankshaft end play at the center journal of the crankshaft.

Do this before removing the crankshaft bearing caps.

If the measured value exceeds the specified limit, the crankshaft thrust bearing must be replaced.

Crankshaft End Play mm(in.)

Standard Limit

0.10 (0.0039) 0.30 (0.0118)

2) Loosen the crankshaft bearing cap bolts in numerical order a little at a time.

If the crankshaft bearings are to be reinstalled, mark their fitting positions by tagging each bearing with the cylinder number from which it was removed.

13. Crankshaft Upper Bearing

If the crankshaft upper bearings are to be reinstalled, mark their fitting positions by tagging each bearing with the cylinder number from which it was removed.

14. Tappet

If the tappets are to be reinstalled, mark their fitting positions by tagging each tappet with the cylinder number from which it was removed.

15. Crankshaft Rear Oil Seal (Axial Type)

Remove the flywheel housing. With the oil seal pushed in deep, install the special

tool as shown in the illustration and remove the oil seal.

Oil Seal Remover: 5-8840-2360-0

Page 42

ENGINE ASSEMBLY ( 1 )

DISASSEMBLY

SINGLE UNIT

ROCKER ARM SHAFT AND ROCKER ARM

Disassembly Steps

▲ 1. Rocker arm shaft snap ring ▲ 2. Rocker arm ▲ 3. Rocker arm shaft bracket

4. Rocker arm

5. Rocker arm shaft spring

6. Rocker arm shaft snap ring

7. Rocker arm shaft

Page 43

ENGINE ASSEMBLY ( 1 )

Important Operations

1. Rocker Arm Shaft Snap Ring

2. Rocker Arm

3. Rocker Arm Shaft Bracket

1) Use a pair of snap ring pliers to remove the snap rings.

2) Remove the rocker arms.

3) Remove the rocker arm shaft bracket. If the rocker arms and rocker arm shaft brackets

are to be reinstalled, mark their installation positions by tagging each rocker arm and rocker arm shaft bracket with the cylinder number from which it was removed.

Page 44

ENGINE ASSEMBLY ( 1 )

CYLINDER HEAD

1 2

Disassembly Steps

▲ 1. Split collar

2. Valve spring upper seat

3. Valve spring

▲ 4. Intake and exhaust valves

5. Valve stem oil seal

6. Valve spring lower washer

7. Cylinder head

Page 45

ENGINE ASSEMBLY ( 1 )

Important Operations

1. Split Collar

1) Place the cylinder head on a flat wooden surface.

2) Use the spring compressor to remove the split collar.

Do not allow the valve to fall from the cylinder head.

Spring Compressor: 9-8523-1423-0

4. Intake and Exhaust Valve

If the intake and exhaust valves are to be reinstalled, mark their installation positions by tagging each valve with the cylinder number from which it was removed.

If there is excessive valve wear or damage, the valve must be replaced.

Refer to Page 50 of “Inspection and Repair” for the valve and valve seat insert procedure.

Note:

If there is excessive valve guide wear or damage, the valve guide must be replaced.

Refer to Page 49 of “Inspection and Repair” for the valve guide replacement procedure.

The valve and the valve guides must be replaced as a set. Never replace only one or the other.

Page 46

ENGINE ASSEMBLY ( 1 )

PISTON AND CONNECTING ROD

Disassembly Steps

▲ 1. Connecting rod bearing ▲ 2. Piston ring ▲ 3. Piston pin snap ring ▲ 4. Piston pin

5. Connecting rod

▲ 6. Piston pin snap ring ▲ 7. Piston

Page 47

ENGINE ASSEMBLY ( 1 )

Important Operations

1. Connecting Rod Bearing

If the connecting rod bearings are to be reinstalled, mark their fitting positions by tagging each bearing with the cylinder number from which it was removed.

2. Piston Ring

1) Clamp the connecting rod in a vise. Take care not to damage the connecting rod.

2) Use a piston pin replacer to remove the piston rings.

Piston Ring Replacer Do not attempt to use some other tool to

remove the piston rings. Piston ring stretching will result in reduced piston ring tension.

3. Piston Pin Snap Ring

4. Piston Pin Snap Ring

Use a pair of snap ring pliers to remove the piston pin snap rings.

5. Piston Pin

7. Piston

Tap the piston pin out with a hammer and a brass bar.

If the pistons are to be reinstalled, mark their installation positions by tagging each piston with the cylinder number from which it was removed.

Page 48

ENGINE ASSEMBLY ( 1 )

CAMSHAFT, CAMSHAFT TIMING GEAR, AND THRUST PLATE

Disassembly Steps

▲ 1. Camshaft timing gear ▲ 2. Thrust plate

3. Feather key

4. Camshaft

Page 49

ENGINE ASSEMBLY ( 1 )

Important Operations

1. Camshaft Timing Gear

2. Thrust Plate

1) Clamp the camshaft in a vise. Take care not to damage the camshaft.

2) Use the universal puller 1 to pull out the camshaft timing gear 2 .

Universal Puller: 5-8840-0086-0

3) Remove the thrust plate 3 .

3

2

1

Page 50

ENGINE ASSEMBLY ( 2 )

SECTION 4

ENGINE ASSEMBLY ( 2 )

TABLE OF CONTENTS

ITEM PAGE

Inspection and repair ............................................................ 48

Page 51

INSPECTION AND REPAIR

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

ENGINE ASSEMBLY ( 2 )

CYLINDER HEAD

Cylinder Head Lower Face Warpage

1. Use a straight edge and a feeler gauge to measure the four sides and the two diagonals of the cylinder head lower face.

2. Regrind the cylinder head lower face if the measured values are greater than the specified limit but less than the maximum grinding allowance.

If the measured values exceed the maximum grinding allowance, the cylinder head must be replaced.

Cylinder Head Lower Face Warpage mm(in)

Standard Limit

Maximum Grinding

Allwance

0.05

0.2 (0.008) 0.3 (0.012)

(0.002) or less

Cylinder Head Height (Reference) mm(in)

Standard Limit

91.95 (3.620) – 92.05 (3.624) 91.65 (3.60)

Note:

If the cylinder head lower face is reground, valve depression must be checked.

Exhaust Manifold Fitting Face Warpage

Use a straight edge and a feeler gauge to measure the manifold cylinder head fitting face warpage.

Regrind the manifold cylinder head fitting faces if the measured values are greater than the specified limit but less than the maximum grinding allowance.

If the measured values exceed the maximum grinding allowance, the cylinder head must be replaced.

Page 52

ENGINE ASSEMBLY ( 2 )

VALVE GUIDE

Valve Stem and Valve Guide Clearance Measuring Method - I

1. With the valve stem inserted in the valve guide, set the dial indicator needle to “0”.

2. Move the valve head from side to side. Read the dial indicator. Note the highest dial indication. If the measured values exceed the specified limit,

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

Valve Stem Clearance mm(in)

Standard Limit

Intake Valve

0.039 – 0.069 0.20

(0.0015 – 0.0027) (0.008)

Exhaust Valve

0.064 – 0.096 0.25

(0.0025 – 0.0038) (0.0098)

Manifold Fitting Face Warpage mm (in)

Standard Limit

Maximum Grinding

Allwance

0.05

0.2 (0.008) 0.4 (0.016)

(0.002) or less

Measuring Method - II

1. Measure the valve stem outside diameter. Refer to the Item “Valve Stem Outside Diameter”.

2. Use a caliper calibrator or a telescoping gauge to measure the valve guide inside diameter.

Valve Guide Replacement

Valve Guide Removal Use a hammer and the valve guide replacer to drive out

the valve guide from the cylinder head lower face. Valve Guide Replacer: 9-8523-1212-0

Page 53

ENGINE ASSEMBLY ( 2 )

Valve Guide Installation

1. Apply engine oil to the valve guide outer circumference.

2. Attach the valve guide replacer to the valve guide.

3. Use a hammer to drive the valve guide into position from the cylinder head upper face.

Valve Guide Replacer: 9-8523-1212-0

4. 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 (0.512)

Note:

If the valve guide has been removed, both the valve and the valve guide must be replaced as a set.

VALVE AND VALVE SEAT INSERT

Valve Stem Outside Diameter

Measure the valve stem diameter at three points. If the measured value is less than the specified limit, the

valve and the valve guide must be replaced as a set. Valve Stem Outside Diameter mm(in)

Standard Limit

Intake Valve

7.949 – 7.961 7.88

(0.3129 – 0.3134) (0.3102)

Exhaust Valve

7.921 – 7.936 7.88

(0.3118 – 0.3124) (0.3102)

Valve Thickness Measure the valve thickness.

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

Intake and Exhaust Valve Thickness mm(in)

Standard Limit

1.8 (0.071) 1.5 (0.059)

Page 54

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.

Valve Contact Width mm(in)

Standard Limit

Intake 1.7 (0.067) 2.2 (0.087)

Exhaust 2.0 (0.079) 2.5 (0.098)

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

Intake 0.73 (0.029) 1.28 (0.050)

Exhaust 0.70 (0.028) 1.20 (0.047)

ENGINE ASSEMBLY ( 2 )

1

2

Valve Seat Insert Replacement

Valve Seat Insert Removal

1. Arc weld the entire inside circumference 1 of the valve seat insert 2.

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.

1

2

3

4

Page 55

ENGINE ASSEMBLY ( 2 )

3. Use a screwdriver 3 to pry the valve seat insert free.

Take care not to damage the cylinder head 4 .

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

Valve Seat Insert Installation

1. Carefully place the attachment 1 (having a smaller outside diameter than the valve seat insert) on the valve seat insert 2 .

Note:

The smooth side of the attachment must contact the valve seat insert.

2. Use a bench press 3 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.

1

2

3

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 areas of the valve seat surface.

Valve Seat Angle 45°

Note:

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

valve guide.

30˚

90˚

150˚

Page 56

Valve Spring Tension

Use a spring tester to measure the valve spring tension. If the measured value is less than the specified limit, the

valve spring must be replace. Valve Spring Tension kgf(lb/N)

Compressed Height Standard Limit

38.9 mm (1.53 in)

32.6 29.0

(71.9/319.6) (63.9/284.4)

ENGINE ASSEMBLY ( 2 )

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 contact width is correct.

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

VALVE SPRING

Valve Spring Free Height

Use a vernier caliper to measure the valve spring free height.

If the measured value is less than the specified limit, the valve spring must be replaced.

Valve Spring Free Height mm(in)

Standard Limit

49.7 (1.96) 48.2 (1.90)

Valve Spring Inclination

Use a surface plate and a square to measure the valve spring inclination.

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

Valve Spring Inclination mm(in)

Standard Limit

1.5 (0.06) or less 2.5 (0.098)

Square

Page 57

Rocker Arm Shaft Outside Diameter

Use a micrometer to measure the rocker arm fitting portion outside diameter.

If the measured value is less than the specified limit, the rocker arm shaft must be replaced.

Rocker Arm Shaft Outside Diameter mm(in)

Standard Limit

18.98 – 19.00 (0.747 – 0.748) 18.85 (0.742)

ENGINE ASSEMBLY ( 2 )

ROCKER ARM SHAFT AND ROCKER ARM

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)

Standard Limit

0.2 (0.008) 0.6 (0.024)

Rocker Arm Shaft and Rocker Arm Clearance

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

Rocker Arm Bushing Inside Diameter mm(in)

Standard Limit

19.01 – 19.03 (0.748 – 0.749) 19.05 (0.750)

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 Arm Shaft Clearance mm(in)

Standard Limit

0.01 – 0.05 (0.0004 – 0.002) 0.2 (0.008)

Page 58

ENGINE ASSEMBLY ( 2 )

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

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

Rocker Arm Correction

Inspect the rocker arm valve stem contact surfaces for step wear 1 and scoring 2 .

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.

CYLINDER BODY

Cylinder Body Upper Face Warpage

1. Remove the cylinder body dowel.

2. Remove the cylinder liner. Refer to “Cylinder Liner Replacement”.

1

2

3. Use a straight edge 1 and a feeler gauge 2 to measure the four sides and the two diagonals of the cylinder body upper face.

1

2

Cylinder Body Upper Face Warpage mm(in)

Standard Limit

0.05 (0.002) or less 0.2 (0.008)

If the measured value is more than the limit, the cylinder body must be replaced.

Page 59

ENGINE ASSEMBLY ( 2 )

Cylinder Body Height (Reference) mm(in)

Standard

247.945 – 248.105 (9.7616 – 9.7679)

4. Reinstall the cylinder liner. Refer to “Cylinder Body Bore Measurement”.

5. Reinstall the cylinder body dowel.

Cylinder Liner Bore Measurement

Use a cylinder indicator to measure the cylinder bore at measuring point 1 in the thrust X – X and axial Y – Y directions of the crankshaft.

Measuring Point 1 : Maximum wear portion

[11 – 15 mm (0.43 – 0.59 in)]

If the measured value exceeds the specified limit, the cylinder liner must be replaced.

Cylinder Liner Bore mm(in)

Standard Limit

93.021 – 93.060 (3.662 – 3.663) 93.10 (3.665)

Note:

The inside of the dry type cylinder liner is chrome plated. It cannot be rebored or honed.

If the inside of the cylinder liner is scored or scorched, the cylinder liner must be replaced.

1

Cylinder Liner Projection Inspection

1. Hold a straight edge 1 along the top edge of the cylinder liner to be measured.

2. Use a feeler gauge 2 to measure each cylinder liner projection.

Cylinder Liner Projection mm(in)

Standard

0 – 0.10 (0 – 0.0039)

The difference in the cylinder liner projection height between any two adjacent cylinders must not exceed 0.03 mm (0.0012 in).

1

2

Page 60

ENGINE ASSEMBLY ( 2 )

Cylinder Liner Replacement Cylinder Liner Removal

1. Insert the cylinder liner remover 1 into the cylinder body (from the lower side of the cylinder body) unit it makes firm contact with the cylinder liner.

Cylinder Liner Remover: 5-8840-2039-0

(A-4JA1, A-4JB1)

2. Use a bench press 2 to slowly force the cylinder liner from the cylinder body.

3. Discard the cylinder liner.

Note:

Take care not to damage the cylinder body upper face during the cylinder liner removal procedure.

4. Measure the cylinder body upper face warpage. Refer to “Cylinder Body Upper Face Warapage”.

Cylinder Liner Grade Selection

Measure the cylinder body inside diameter and select the proper cylinder liner grade number corresponding to the cylinder body inside diameter.

Standard Fitting Interference (Reference) mm(in)

0.001 – 0.019 (0.00004 – 0.00075)

If the cylinder liner fitting interference is too small, engine cooling efficiency will be adversely affected.

If the cylinder liner fitting interference is too large, it will be difficult to insert the cylinder liner into the cylinder body.

Cylinder Body Bore Measurement

1. Take measurements at measuring point 1 across positions (“W – W”), (“X – X”), (Y – Y) and (Z – Z).

Measuring Point 1 : 98 mm (3.86 in)

2. Calculate the average value of the four measurements to determine the correct cylinder grade.

Cylinder Liner Grade

Nominal Cylinder Body

Liner Grade

Dimension Bore Diameter

95.001 – 95.010 1

(3.74019 – 3.74055)

95.011 – 95.020 2

(3.74059 – 3.74094)

95.021 – 95.030 3

(3.74098 – 3.74133)

95.031 – 95.040 4

(3.74138 – 3.74173)

φ95

Page 61

ENGINE ASSEMBLY ( 2 )

Cylinder Liner Installation

1. Cylinder Liner Installation Using The Special Tool.

1) Use new kerosene or diesel oil to thoroughly clean the cylinder liners and bores.

2) Use compressed air to blow-dry the cylinder liner and bore surfaces.

Note:

All foreign material must be carefully removed from the cylinder liner and the cylinder bore before installation.

3) Insert the cylinder liner 1 into the cylinder body 2 from the top of the cylinder body.

1

2

3

4) Set the cylinder liner installer 3 to the top of the cylinder liner.

Cylinder Liner Installer: 5-8840-2040-0

5) Position the cylinder body so that the installer center 3 is directly beneath the bench press shaft center 4.

Note:

Check that the cylinder liner is set perpendicular to the bench press and that there is no wobble.

6) Use the bench press to apply a seating force of 500 kgf (1,102.5 lb/4,900 N) to the cylinder liner.

7) Apply a force of 2,500 kgf (5,512.5 lb/24,500 N) to fully seat the cylinder liner.

8) After installing the cylinder liner, measure the cylinder liner projection.

Refer to “Cylinder Liner Projection Inspection”.

2. Cylinder Liner Installation Using Dry Ice If the cylinder liner is a chrome plated dry type, it is

advisable to use dry ice during the installation procedure.

Cooling the cylinder liner with dry ice will cause the cylinder liner to contact, thus making installation easier.

Note:

It is important that the cylinder liner be inserted to the cylinder body immediately after it has been cooled.

3

4

Page 62

ENGINE ASSEMBLY ( 2 )

WARNING:

DRY ICE MUST BE USED WITH GREAT CARE. CARELESS HANDLING OF DRY ICE CAN RESULT IN SEVERE FROSTBITE.

Piston Selection

Select the same grade number as the one for the cylinder liner inside diameter.

Grade of cylinder

Grade of piston Combination

inside diameter

AX AX OK CX CX OK

AX CX NG CX AX NG

Page 63

ENGINE ASSEMBLY ( 2 )

Piston Grade Selection

Measure the cylinder liner bore. Then select the appropriate piston grade for the installed cylinder liner.

1. Measure the cylinder liner bore. There are two measuring points ( 1 and 2 ). Measure the cylinder liner bore in four different

direction (W – W, X – X, and Z – Z) at both measuring points.

Calculate the average value of the eight measurements to determine the correct cylinder liner bore.

Measuring Points 1 :

20 mm (0.79 in) for all A-4J models

2 :

140 mm (5.51 in) for A-4JA1 160 mm (6.30 in) for A-4JB1

Cylinder Liner Bore mm(in)

Standard Limit

93.021 – 93.060 (3.662 – 3.663) 93.10 (3.665)

Note:

It is most important that the correct piston grade be used. Failure to select the correct piston grade will result in engine failure.

1

2

2. Measure the piston outside diameter.

Piston Measuring Point 1 : 70 mm (2.76 in) Piston Grade mm(in)

Grade

Piston Outside Diameter

4JA1 4JB1

92.979 – 92.994 92.989 – 93.004

(3.6606 – 3.6611) (3.6610 – 3.6615)

92.995 – 93.010 93.005 – 93.020

(3.6612 – 3.6618) (3.6616 – 3.6622)

Cylinder Liner and Piston Clearance mm(in)

0.017 – 0.055 (0.0007 – 0.0022)

Note:

:Cylinder liner kit clearances are preset. However, the cylinder liner installation procedure may result in slight decreases in cylinder liner clearances. Always measure the cylinder liner clearance after installation to be sure that it is correct.

1

Page 64

ENGINE ASSEMBLY ( 2 )

TAPPET AND PUSH ROD

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.

1 Pitting 2 Cracking 3 Normal contact 4 Irregular contact 5 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.

123

Tappet Outside Diameter

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)

Standard Limit

12.97 – 12.99 (0.5106 – 0.5114) 12.95 (0.5098)

Page 65

ENGINE ASSEMBLY ( 2 )

Tappet and Cylinder Body Clearance mm(in)

Standard Limit

0.03 (0.0012) 0.1 (0.0039)

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

Push Rod Curvature mm(in)

Limit

0.3 (0.012)

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.

CAMSHAFT

Visually inspect the journals, the cams, the oil pump drive gear, and the camshaft bearings for excessive wear and damage. The camshaft and the camshaft bearings must be replaced if these conditions are discovered during inspection.

Camshaft Journal Diameter

Use a micrometer to measure each camshaft journal diameter in two directions ((X – X) and (Y – Y)). If the measured value is less than the specified limit, the camshaft must be replaced.

Camshaft Journal Diameter mm(in)

Standard Limit

49.945 – 49.975 49.60

(1.9663 – 1.9675) (1.953)

Page 66

ENGINE ASSEMBLY ( 2 )

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 H mm(in)

Standard Limit

42.08 (1.65) 41.65 (1.64)

Camshaft Run-Out

1. Mount the camshaft on V-blocks.

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

the camshaft must be replaced.

Camshaft Run-Out mm(in)

Standard Limit

0.02 (0.0008) 0.10 (0.004)

Camshaft and Camshaft Bearing

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

Camshaft Bearing Inside Diameter mm(in)

Standard Limit

50.0 – 50.03 50.08

(1.9685 – 1.9697) (1.9716)

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

Camshaft Bearing Clearance mm(in)

Standard Limit

0.05 (0.002) 0.12 (0.005)

Camshaft Bearing Replacement Camshaft Bearing Removal

1. Remove the cylinder body plug plate.

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

Bearing Replacer: 5-8840-2038-0

Page 67

ENGINE ASSEMBLY ( 2 )

Camshaft Bearing Installation

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

2. Use the camshaft bearing replacer installer to install the camshaft bearing.

Bearing Replacer: 5-8840-2038-0

Camshaft End Play

1. Before removing the camshaft gear 1, push the thrust plate 2 as far as it will go toward the camshaft gear 3.

2. Use a feeler gauge to measure the clearance between the thrust plate and the camshaft journal. If the measured value exceeds the specified limit, the thrust plate must be replaced.

Camshaft End Play mm(in)

Standard Limit

0.050 – 0.114 (0.002 – 0.0045) 0.2 (0.008)

1

2

3

Thrust Plate Replacement Thrust Plate Removal

1. Use the universal puller 1 to remove the camshaft timing gear 2 .

Universal Puller: 5-8840-0086-0

2. Remove the thrust plate 3 .

1

2

3

Thrust Plate Installation

1. Install the thrust plate.

2. Apply engine oil to the bolt setting face and the bolt threads.

3. Install the camshaft gear.

Camshaft Gear Torque kgf·m(lb.ft/N·m)

10.0 – 12.0 (72.4 – 86.8/98.1 – 117.7)

Page 68

ENGINE ASSEMBLY ( 2 )

CRANKSHAFT AND BEARING

Inspect the surface of the crankshaft journals and crankpins for excessive wear and damage.

Inspect the oil seal fitting surfaces for excessive wear and damage.

Inspect the oil ports for obstructions.

Note:

To increase crankshaft strength, tufftriding (Nitrizing Treatment) has been applied. Because of this, it is not possible to regrind the crankshaft surfaces.

Crankshaft Tufftriding Inspection

1. Use an organic cleaner to thoroughly clean the crankshaft. There must be no traces of oil on the surfaces to be inspected.

2. Prepare a 5 – 10% solution of ammonium cuprous chloride (dissolved in distilled water).

3. Use a syringe to apply the solution to the surface to be inspected.

Hold the surface to be inspected perfectly horizontal to prevent the solution from running.

Note:

Do not allow the solution to come in contact with the oil ports and their surrounding area.

The portion to be tested shall be held horizontally so as not to let the test solution flow.

The sliding surface of the pin or journal.

Test liquid should not be applied to the area around the oil port.

Approximately 10mm

Judgment

1. Wait for thirty to forty seconds. If there is no discoloration after thirty or forty sec-

onds, the crankshaft is usable. If discoloration appears (the surface being tested

will become the color of copper), the crankshaft must be replaced.

2. Steam clean the crankshaft surface immediately after completing the test.

Page 69

Crankshaft Run-Out

1. Set a dial indicator to the center of the crankshaft journal.

2. Gently turn the crankshaft in the normal direction of rotation. Read the dial indicator as you turn the crankshaft. If the measured value exceeds the specified limit, the crankshaft must be replaced.

Crankshaft Run-Out mm(in)

Standard Limit

0.05 (0.002) or less 0.08 (0.0031)

ENGINE ASSEMBLY ( 2 )

Note:

The ammonium cuprous chloride solution is highly corrosive. Because of this, it is imperative that the surfaces being tested be cleaned immediately after completing the test.

Bearing Tension

Check to see if the bearing has enough tension, so that a good finger pressure is needed to fit the bearing into position.

Crankshaft Journal and Crankpin Diameter

1. Use a micrometer to measure the crankshaft journal diameter across points (“1 – 1”) and (“2 – 2”).

2. Use the micrometer to measure the crankshaft journal diameter at the two points ( 3 and 4 ).

3. Repeat Steps 1 and 2 to measure the crankpin diameter.

If the measured values are less than the limit, the crankshaft must be replaced.

3

4

Page 70

ENGINE ASSEMBLY ( 2 )

Crankshaft Journal Diameter mm(in)

Standard Limit

A-4JA1

59.917 – 59.932 59.910

(2.3589 – 2.3595) (2.3587)

A-4JB1

69.917 – 69.932 69.910

(2.7526 – 2.7531) (2.7524)

Crankpin Diameter mm(in)

Standard Limit

52.915 – 52.930 (2.0833 – 2.0839) 52.906 (2.0829)

Crankshaft Journal and Crankpin Uneven Wear mm(in)

Standard Limit

0.05 (0.002) or less 0.08 (0.0031)

Crankshaft Journal and Bearing Clearance

If the clearance between the measured bearing inside diameter and the crankshaft journal diameter exceeds the specified limit, the bearing and/or the crankshaft must be replaced.

Crankshaft Bearing Cap Bolt Torque kgf·m(lb.ft./N·m)

16.0 – 18.0 (115.7 – 130.2/156.9 – 176.5)

Crankshaft brg’ cap Bolt Torque Crankshaft Journal and

Bearing Clearance mm(in)

Standard Limit

0.035 – 0.080 (0.0014 – 0.0031) 0.11 (0.0043)

Connecting Rod Bearing Inside Diameter

1. Install the bearing to the connecting rod big end.

2. Tighten the bearing cap to the specified torque.

Connecting Rod Bearing Cap Bolt Torque kgf·m(lb.ft/N·m)

8.0 – 9.0 (57.9 – 65.1/78.4 – 88.2)

3. Use a inside dial indicator to measure the connecting rod bearing inside diameter.

Page 71

ENGINE ASSEMBLY ( 2 )

Crankpin and Bearing Clearance

If the clearance between the measured bearing inside diameter and the crankpin exceeds the specified limit, the bearing and/or the crankshaft must be replaced.

Crankpin and Bearing Clearance mm(in)

Standard Limit

0.029 – 0.066 (0.0011 – 0.0026) 0.10 (0.0039)

Clearance Measurements (With Plastigage)

Crankshaft Journal and Bearing Clearance

1. Clean the cylinder body, the journal bearing fitting surface, the bearing caps, and the bearings.

2. Install the bearings to the cylinder body.

3. Carefully place the crankshaft on the bearings.

4. Rotate the crankshaft approximately 30° to seat the bearing.

5. Place the Plastigage (arrow) over the crankshaft journal across the full width of the bearing.

6. Install the bearing caps with the bearing.

7. Tighten the bearing caps to the specified torque.

Crankshaft Bearing Cap Bolt Torque kgf·m(lb.ft/N·m)

16.0 – 18.0 (115.7 – 130.2/156.9 – 176.5)

Do not allow the crankshaft to turn during bearing cap installation and tightening.

8. Remove the bearing cap.

Page 72

ENGINE ASSEMBLY ( 2 )

9. Compare the width of the Plastigage attached to either the crankshaft or the bearing against the scale printed on the Plastigage container.

If the measured value exceeds the limit, perform the following additional steps.

1) Use a micrometer to measure the crankshaft outside diameter.

2) Use an inside dial indicator to measure the bearing inside diameter.

If the crankshaft journal and bearing clearance exceeds the limit, the crankshaft and/or the bearing must be replaced.

Crankshaft Journal and Bearing Clearance mm(in)

Standard Limit

0.035 – 0.080 0.11

(0.0014 – 0.0036) (0.0043)

Crankpin and Bearing Clearance

1. Clean the crankshaft, the connecting rod, the bear ing cap, and the bearings.

2. Install the bearing to the connecting rod and the bearing cap.

Do not allow the crankshaft to move when installing the bearing cap.

3. Prevent the connecting rod from moving.

4. Attach the Plastigage to the crankpin. Apply engine oil to the Plastigage to keep it from

falling.

Page 73

ENGINE ASSEMBLY ( 2 )

5. Install the bearing cap and tighten it to the specified torque.

Do not allow the connecting rod to move when installing and tightening the bearing cap.

Connecting Rod Bearing Cap Bolt Torque kgf·m(lb.ft/N·m)

8.0 – 9.0 (57.9 – 65.1/78.4 – 88.2)

6. Remove the bearing cap.

7. Compare the width of the Plastigage attached to either the crankshaft or the bearing against the scale printed on the Plastigage container.

If the measured value exceeds the specified limit, perform the following additional steps.

1) Use a micrometer to measure the crankpin outside diameter.

2) Use an inside dial indicator to measure the bearing inside diameter.

If the crankpin and bearing clearance exceeds the specified limit, the crankshaft and/or the bearing must be replaced.

Crankpin and Bearing Clearance mm(in)

Standard Limit

0.029 – 0.066 0.10

(0.0011 – 0.0026) (0.0039)

Crankshaft Timing Gear Replacement Crankshaft Timing Gear Removal

1. Use the crankshaft gear remover 1 to remove the crankshaft gear 2 .

2. Remove the crankshaft feather key. Crankshaft Timing Gear Remover: 9-8840-2057-0

1

2

Crankshaft Timing Gear Installation

1. Install the crankshaft gear.

2. Use the crankshaft gear installer 1 to install the crankshaft gear 2 .

The crankshaft gear timing mark (“X – X”) must be facing outward.

Crankshaft Gear Installer: 9-8522-0020-0

1

2

Page 74

ENGINE ASSEMBLY ( 2 )

CRANKSHAFT PILOT BEARING

Check the crankshaft pilot bearing for excessive wear and damage and replace it if necessary.

Crankshaft Pilot Bearing Replacement

Crankshaft Pilot Bearing Removal Use the pilot bearing remover to remove the pilot bear-

ing. Pilot Bearing Remover: 5-8840-2000-0

Sliding Hammer: 5-8840-0019-0

Crankshaft Pilot Bearing Installation

1. Place the crankshaft pilot bearing horizontally across the crankshaft bearing installation hole.

2. Tap around the edges of the crankshaft pilot bearing outer races with a brass hammer to drive the bearing into the crankshaft bearing installation hole.

Pilot Bearing Installer: 5-8522-0024-0

Note:

Strike only the crankshaft pilot bearing outer races with the hammer. Do not strike the bearing inner races. Bearing damage and reduced bearing service life will result.

Page 75

ENGINE ASSEMBLY ( 2 )

FLYWHEEL AND RING GEAR

Flywheel

1. Inspect the flywheel friction surface for excessive wear and heat cracks.

2. Measure the flywheel friction surface wear amount (depth)

The flywheel friction surface area actually making contact with the clutch driven plate (the shaded area in the illustration) will be smaller than the original machined surface area.

There will be a ridge on the flywheel surface area. Be sure to measure the surface wear in the area inside the ridge.

If the measured value is between the standard and the specified limit, the flywheel may be reground.

If the measured value exceeds the specified limit, the flywheel must be replaced.

Flywheel Friction Surface Depth 1 mm(in)

Limit

1.0 (0.04) or more

Note:

Because a ridge is produced at the flywheel friction surface as illustrated, do not measure the friction surface wear amount at the non-ridge area but be sure to measure it at the rear-friction surface which is shown in the illustration by shaded area.

1

Ring Gear Replacement Ring Gear Removal

Strike around the edges of the ring gear with a hammer and diesel to remove it.

Ring Gear

Inspect the ring gear. If the ring gear teeth are broken or excessively worn, the

ring gear must be replaced.

Page 76

ENGINE ASSEMBLY ( 2 )

Ring Gear Installation

1. Heat the ring gear evenly with a gas burner to invite thermal expansion.

Do not allow the temperature of the gas burner to exceed 200°C (390°F).

2. Install the ring gear when it is sufficiently heated. The ring gear must be installed with the chamfer

facing the clutch.

Note:

Another method of heating the ring gear to invite thermal expansion is to soak a rag in diesel fuel, wrap the diesel fuel soaked rag around the rim of the ring gear, and then light the rag.

1

2

PISTON RING

Piston Ring Gap

1. Insert the piston ring horizontally into the cylinder liner.

2. Use a piston inserted upside down to push the piston ring into the cylinder liner until it reaches either measuring point 1 or measuring point 2. Cylinder liner diameter is the smallest at these two points.

Do not allow the piston ring to slant to one side or the other. It must be perfectly horizontal.

3. Use a feeler gauge to measure the piston ring gap. Measuring Point 1 : 10 mm (0.39 in)

Measuring Point 2 : 120 mm (4.72 in) If the piston ring gap exceeds the specified limit, the

piston ring must be replaced.

PISTON

Piston Grade Selection and Cylinder Liner Bore Measurement

Refer to the Section “CYLINDER BODY”, Item “Cylinder Liner Bore Measurement” for details on piston grade selection and cylinder or liner bore measurement.

Page 77

ENGINE ASSEMBLY ( 2 )

Piston Ring Gap mm(in)

Standard Limit

1st Compression Ring

0.20 – 0.40

2nd Compression Ring

(0.008 – 0.016)

Oil Ring

0.10 – 0.30

(0.004 – 0.012)

Piston Ring and Piston Ring Groove Clearance

Use a feeler gauge to measure the clearance between the piston ring and the piston ring groove at several points around the piston.

If the clearance between the piston ring and the piston ring groove exceeds the specified limit, the piston ring must be replaced.

Piston Ring and Piston Ring Groove Clearance mm(in)

Standard Limit

1st

Compression Ring

0.090 – 0.125

(0.0035 – 0.0049)

2nd Compression Ring

0.050 – 0.075 0.15

(0.002 – 0.003) (0.006)

Oil Ring

0.030 – 0.070

(0.0012 – 0.0028)

Visually inspect the piston. If a piston ring groove is damaged or distorted, the piston must be replaced.

1.5

(0.059)

Page 78

PISTON PIN

Piston Pin Diameter

Use a micrometer to measure the piston pin outside diameter at several points. If the measured value is less than the specified limit, the piston pin must be replaced.

Piston Pin Diameter mm(in)

Standard Limit

31.0 (1.220) 30.97 (1.219)

Piston Pin and Piston Clearance

Use an inside dial indicator to measure the piston pin hole (in the piston).

Piston Pin Hole mm(in)

Standard

29.002 – 29.007

Piston Pin and Piston Pin Hole Clearance mm(in)

0.002 – 0.015 (0.00008 – 0.0006)

Piston Pin and Connecting Rod Small End Bushing Clearance

Use a caliper calibrator and a dial indicator to measure the piston pin and connecting rod small end bushing clearance.

If the clearance between the piston pin and the connecting rod small end bushing exceeds the specified limit, replace the piston pin and/or the connecting rod bushing.

Piston Pin and Connecting Rod Small End Bushing Clearance mm(in)

Standard Limit

0.008 – 0.020 0.05

(0.0003 – 0.0008) (0.002)

ENGINE ASSEMBLY ( 2 )

Connecting Rod Bushing Replacement Connecting Rod Bushing Removal

1. Clamp the connecting rod in a vise.

2. Use the connecting rod bushing remover to remove the connecting rod bushing.

Connecting Rod Bushing Replacer

Page 79

CONNECTING ROD

Connecting Rod Alignment

Use a connecting rod aligner to measure the distortion and the parallelism between the connecting rod big end hole and the connecting rod small end hole.

If either the measured distortion or parallelism exceed the specified limit, the connecting rod must be replaced.

Connecting Rod Alignment Per Length of 100 mm (3.94 in) mm(in)

Standard Limit

Distortion

0.20

0.05 or Less

(0.008)

(0.002)

0.15

Parallelism

(0.006)

ENGINE ASSEMBLY ( 2 )

Connecting Rod Bushing Installation

1. Clamp the connecting rod in a vice.

2. Use the connecting rod bushing installer to install the connecting rod bushing.

Connecting Rod Bushing Replacer:

3. Use a piston pin hole grinder 1 fitted with a reamer 2 to ream the piston pin hole.

1

2

Page 80

ENGINE ASSEMBLY ( 2 )

Connecting Rod Side Face Clearance

1. Install the connecting rod to the crankpin.

2. Use a feeler gauge to measure the clearance between the connecting rod big end side face and the crankpin side face.

If the measured value exceeds the specified limit, the connecting rod must be replaced.

Connecting Rod and Crankpin Side Face Clearance mm(in)

Standard Limit

0.23 (0.009) 0.35 (0.014)

IDLER GEAR SHAFT AND IDLER GEAR

Idler Gear Shaft Outside Diameter

Use a micrometer to measure the idler gear shaft outside diameter.

If the measured value is less than the specified limit, the idler gear must be replaced.

Idler Gear Shaft Outside Diameter mm(in)

Standard Limit

44.95 – 44.98 44.90

(1.770 – 1.771) (1.767)

Page 81

ENGINE ASSEMBLY ( 2 )

Idler Gear “A” Inside Diameter

1. Use an inside dial indic ator to measure the idler gear

Idler Gear Inside Diameter mm(in)

Standard Limit

45.0 – 45.03 45.10

(1.7717 – 1.7728) (1.7756)

If the clearance between the idler gear shaft outside diameter and the idler gear inside diameter exceeds the limit, the idler gear must be replaced.

Idler Gear Shaft and Idler Gear Clearance mm(in)

Standard Limit

0.025 – 0.085 0.2

(0.0010 – 0.0033) (0.008)

Idler Gear “B” Bearing replacement

Use a suitable bar and a bench press or hammer. Bearing projection amount should be within the spec-

ified height.

mm(in) Projection 1 0.4 – 0.6 (0.016 – 0.024) Height 2 23.7 – 24.0 (0.933 – 0.945)

1

2

Crankshaft Front Oil Seal Replacement Oil Seal Removal

Use a plastic hammer and a screwdriver to tap around the oil seal to free it from the gear case.

Take care not to damage the oil seal fitting surfaces.

TIMING GEAR CASE COVER

Replace the crankshaft front oil seal if it is excessively worn or damaged.

Page 82

ENGINE ASSEMBLY ( 2 )

Oil Seal Installation

1. Apply a coat of engine oil to the oil seal lip circumference.

2. Use the oil seal installer and the installer grip to insert the oil seal 1 mm (0.039 in) into the front portion of the timing gear case.

Oil Seal Installer: 5-8840-2061-0

Page 83

MEMO

Page 84

ENGINE ASSEMBLY ( 3 )

SECTION 5

ENGINE ASSEMBLY ( 3 )

TABLE OF CONTENTS

ITEM PAGE

Reassembly..................................................................... 82

Page 85

REASSEMBLY

SINGLE UNIT

ROCKER ARM SHAFT AND ROCKER ARM

ENGINE ASSEMBLY ( 3 )

Reassembly Steps

▲ 1. Rocker arm shaft

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 snap ring

Page 86

ENGINE ASSEMBLY ( 3 )

Important Operations

1. Rocker Arm Shaft

1) Position the rocker arm shaft with the large oil hole (Dia. 4 mm (0.157 in)) facing the front of the engine.

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

Page 87

ENGINE ASSEMBLY ( 3 )

CYLINDER HEAD

Reassembly Steps

1. Cylinder head

2. Valve spring lower washer

▲ 3. Valve stem oil seal ▲ 4. Intake and exhaust valve

▲ 5. Valve spring

6. Valve spring upper seat

▲ 7. Split collar

7 6

Page 88

ENGINE ASSEMBLY ( 3 )

3. Valve Stem Oil Seal

1) Apply a coat engine oil to the oil seal inner face.

2) Use an oil seal installer to install the oil seal to the valve guide.

Oil Seal Installer: 5-8840-2033-0

4. Intake and Exhaust Valve

1) Apply a coat of engine oil to valve stem.

2) Install the intake and exhaust valves.

3) Turn the cylinder head up to install the valve springs.

Take care not to allow the installed valves to fall free.

5. Valve Spring

1) Turn the cylinder head up to install the valve springs.

2) Install the valve springs with the fine pitched end (painted pink) facing down.

Take care not to allow the installed valves to fall free.

7. Split Collar

1) Use the spring compressor to push the valve spring into position.

Spring Compressor: 9-8523-1423-0

2) Install the split collar to the valve stem.

3) Set the split collar by tapping around the bead of the collar with a rubber hammer.

Important Operations

Page 89

ENGINE ASSEMBLY ( 3 )

PISTON AND CONNECTING ROD

Reassembly Steps

▲ 1. Piston ▲ 2. Piston pin snap ring ▲ 3. Connecting rod ▲ 4. Piston pin

5. Piston pin snap ring

▲ 6. Piston ring ▲ 7. Connecting rod bearing

Page 90

ENGINE ASSEMBLY ( 3 )

1. Piston

2. Piston pin snap ring

3. Connecting rod

1) Clamp the connecting rod in a vise. Take care not to damage the connecting rod.

2) Use a pair of snap ring pliers to install the piston pin snap ring to the piston.

3) Install the piston to the connecting rod. The piston head front mark 1 and the con-

necting rod “ISUZU” casting mark 2 must be facing the same direction.

Important Operations

4. Piston pin

1) Apply a coat of engine oil to the piston pin and the piston pin hole.

2) Use your fingers to force the piston pin into the piston until it makes contact with the snap ring.

3) Use your fingers to force the piston pin snap ring into the piston snap ring groove.

4) Check that the connecting rod moves smoothly on the piston pin.

Page 91

ENGINE ASSEMBLY ( 3 )

6. Piston Ring

1) Use a piston ring replacer to install the three piston rings.

Piston Ring Replacer:

Install the piston rings in the order shown in the illustration.

1 Oil ring (Coil expander type) 2 2nd compression ring (Taper undercut type) 3 1st compression ring (Barrel face type)

Note:

Install the compression rings with the stamped side facing up.

Insert the expander coil into the oil ring groove so that there is no gap on either side of the expander coil before installing the oil ring.

2) Apply engine oil to the piston ring surfaces.

3) Check that the piston rings rotate smoothly in the piston ring grooves.

1

2

3

7. Connecting Rod Bearing

Carefully wipe any oil or other foreign material from the connecting rod bearing back face and the connecting rod bearing fitting surface.

Page 92

ENGINE ASSEMBLY ( 3 )

CAMSHAFT, CAMSHAFT TIMING GEAR, AND THRUST PLATE

Reassembly Steps

1. Camshaft

2. Feather key

3. Thrust plate

▲ 4. Camshaft timing gear

Page 93

ENGINE ASSEMBLY ( 3 )

4. Camshaft Timing Gear

1) Install the thrust plate 1 .

2) Apply engine oil to the bolt threads 2 .

3) Install the camshaft timing gear with the timing mark stamped side facing out.

Camshaft Timing Gear Bolt Torque kgf·m(lb.ft/N·m)

10.0 – 12.0 (72.4 – 86.8/98.1 – 117.7)

1

2

Important Operations

Page 94

ENGINE ASSEMBLY ( 3 )

MEMO

Page 95

ENGINE ASSEMBLY ( 3 )

REASSEMBLY

15a

★

16a

★

★Repair kit

Reassembly Steps – 1

▲ 1. Cylinder body ▲ 2. Tappet ▲ 3. Crankshaft upper bearing ▲ 4. Crankshaft with crankshaft timing gear ▲ 5. Crankshaft thrust bearing ▲ 6. Crankshaft bearing cap with lower

bearing

▲ 7. Timing gear case ▲ 8. Camshaft with camshaft timing gear

and thrust plate

▲ 9. Piston and connecting rod with upper

bearing

▲ 10. Connecting rod cap with lower bearing ▲ 11. Crankcase (If so equipped) ▲ 12. Oil pump with oil pipe ▲ 13. Crankshaft rear oil seal ▲ 14. Flywheel housing ▲ 15. Flywheel

15a Rear flywheel (If so equipped)

▲ 16. Oil pan

16a Oil pan (If so crankcase equipped)

Inverted Engine

Page 96

ENGINE ASSEMBLY ( 3 )

★

★Repair kit

★

Reassembly Steps – 2

▲ 1. Idler gear shaft ▲ 2. Idler gear “A” ▲ 3. Idler gear “B”

4. Timing gear oil pipe

▲ 5. Timing case cover

6. Timing gear case cover

▲ 7. Crankshaft damper pulley with dust

seal

▲ 8. Cylinder head gasket ▲ 9. Cylinder head

10. Push rod

▲ 11. Rocker arm shaft and rocker arm ▲ 12. Water pump ▲ 13. Thermostat housing

14. Water by-pass hose

▲ 15. Glow plug and glow plug connector

seal

▲ 16. Injection nozzle holder

17. Cylinder head cover

Page 97

ENGINE ASSEMBLY ( 3 )

1. Cylinder Body

Use compressed air to thoroughly clean the inside and outside surfaces of the cylinder body, the oil holes, and the water jackets.

Important Operations (Reassembly Steps-1)

2. 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 applied at disassembly (if the tappet is to be reused).

Note:

The tappet must be installed before the camshaft.

1

2

3. Crankshaft Upper Bearing

The crankshaft upper bearings have an oil hole and an oil groove. The lower bearings do not.

1) Carefully wipe any foreign material from the crankshaft upper bearing and the crankshaft upper bearing fitting surfaces.

2) Locate the position mark applied at disassembly if the removed crankshaft upper bearings are to be reused.

4. Crankshaft with Crankshaft Timing Gear

Apply an ample coat of engine oil to the crankshaft journals and the crankshaft bearing surfaces before installing the crankshaft.

Note:

Do not apply engine oil to the bearing back faces and the cylinder body bearing fitting surfaces.

Page 98

ENGINE ASSEMBLY ( 3 )

5. Crankshaft Thrust Bearing

1) Apply an ample coat of engine oil to the crankshaft thrust bearings.

2) Install the crankshaft thrust bearings to the crankshaft center journal.

The crankshaft thrust bearing oil groove must be facing the sliding face.

6. Crankshaft Bearing Cap with Lower Bearing

1) Apply silicon adhesive to the cylinder body No. 5 bearing cap fitting surface at the points shown in the illustration.

Note:

Be sure that the bearing cap fitting surface is completely free of oil before applying the silicon adhesive.

Do not allow the silicon adhesive to obstruct the cylinder thread holes and bearings.

2) Install the bearing caps. The bearing cap arrow marks must be facing the

front of the engine. The arrow mark journal number must corre-

spond to the journal to which the bearing cap is installed.

Note:

The No. 4 journal bearing cap does not have a number stamped on it.

1 2 3 Nile

3) Apply a coat of engine oil to the bearing cap bolts.

4) Tighten the crankshaft bearing cap bolts to the specified torque a little at a time in the sequence shown in the illustration.

Crankshaft Bearing Cap Torque kgf·m(lb.ft/N·m)

16.0 – 18.0 (115.7 – 130.2/156.9 – 176.5)

5) Check to see that the crankshaft turns smoothly by rotating it manually.

1

23

4

5

6

7

8

9

10

7. Timing Gear Case

1) Tighten the timing gear case with timing gear case gasket to the specified torque.

Timing Gear Case Bolt Torque kgf·m(lb.ft/N·m)

1.4 – 2.4 (10.1 – 17.3/13.7 – 23.5)

2) Cut away any excessive flash from the timing gear gasket.

Page 99

ENGINE ASSEMBLY ( 3 )

8. Camshaft with Camshaft Timing Gear and Thrust Plate

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 to damage the camshaft bearings.

3) Tighten the thrust plate to the specified torque.

Thrust Plate Bolt Torque kgf·m(lb.ft/N·m)

1.4 – 2.4 (10.1 – 17.3/13.7 – 23.5)

4) Check to see that the camshaft turns smoothly by rotating it manually.

9. Piston and Connecting Rod with Upper Bearing

10. Connecting Rod Bearing Cap with Lower Bearing

1) Apply a coat of engine oil to the circumference of each piston ring and piston.

1

2

3

2) Position the piston ring gaps as shown in the illustration.

1 1st compression ring 2 2nd compression ring 3 Oil ring

3) Apply a coat of molybdenum disulfide grease to the two piston skirts.

This will facilitate smooth break-in when the engine is first started after reassembly.

1

2

3

4) Apply a coat of engine oil to the upper bearing surfaces.

Note:

Do not apply engine oil to the bearing back faces and the connecting rod bearing fitting surfaces.

5) Apply a coat of engine oil to the cylinder wall.

Page 100

ENGINE ASSEMBLY ( 3 )

6) Position the piston head front mark so that it is facing the front of the cylinder body.

7) Use a piston ring compressor to compress the piston rings.

Piston Ring Compressor

8) Use a hammer grip to push the piston in until the connecting rod makes contact with the crankpin.

At the same time, rotate the crankshaft until the crankpin is at BDC.

9) Install the connecting rod bearing caps. The bearing cap front marks must be facing the

front of the engine. The bearing cap number (at the side of the

bearing cap) and the connecting rod number must be the same.

Note:

It is absolutely essential that the bearing caps be installed in the correct direction. Reversing the bearing cap direction will result in serious engine damage.

10) Apply a coat of engine oil to the threads and setting faces of each connecting rod cap bolt.

11) Tighten the connecting rod caps to the specified torque.

Connecting Rod Cap Bolt Torque kgf·m(lb.ft/N·m)

8.0 – 9.0 (57.9 – 65.1/78.4 – 88.2)

11. Crankcase (if so equipped)

1) Apply sealant to the No. 5 bearing cap arches, the bearing grooves, and the timing gear case arches at the positions shown in the illustration.

2) Apply sealant to the crankcase cylinder body fitting area.

3) Tighten the crankcase bolts to the specified torque a little at a time in the sequence shown in the illustration.

Crankcase Bolt Torque kgf·m(lb.ft/N·m)

1.4 – 2.4 (10.1 – 17.3/13.7 – 23.5)

Isuzu A-4JA1, 4ja1, A-4JB1 Workshop Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

GENERAL INFORMATION

SECTION 1

GENERAL REPAIR INSTRUCTIONS

NOTES ON THE FORMAT OF THIS MANUAL

MAIN DATA AND SPECIFICATIONS

MAINTENANCE

SECTION 2

MODEL IDENTIFICATION

INJECTION PUMP IDENTIFICATION

LUBRICATING SYSTEM

FUEL SYSTEM

COOLING SYSTEM

VALVE CLEARANCE ADJUSTMENT

INJECTION TIMING

COMPRESSION PRESSURE MEASUREMENT

RECOMMENDED LUBRICANTS

ENGINE REPAIR KIT

ENGINE ASSEMBLY ( 1 )

SECTION 3

GENERAL DESCRIPTION

DISASSEMBLY

ENGINE ASSEMBLY ( 2 )

SECTION 4

INSPECTION AND REPAIR

ENGINE ASSEMBLY ( 3 )

SECTION 5

REASSEMBLY