Content .. 28 29 30 31 ..

Isuzu engine 4j series. Manual - part 30

6A – 56

GENERAL ENGINE MECHANICAL

CYLINDER BLOCK

DISASSEMBLY

1. Cylinder Head Assembly and Gasket

2. Oil Pan Assembly

3. Timing Gear

3a. Timing Belt and Pulley

4. Front Oil Seal (Belt Drive Model)

5. Timing Gear Housing

5a. Timing Pulley Housing

6. Oil Pump Assembly

6A-56-1.tif

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
14. Camshaft
15. Tappet
16. Cylinder block

Reassembly steps

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

GENERAL ENGINE MECHANICAL 6A – 57

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

14. Camshaft

15. Tappet

16. Cylinder Block

INSPECTION AND REPAIR

Make the necessary adjustments, repairs, and part
replacements if excessive wear or damage is discovered
during inspection.
1. Remove the gasket and any other material adhering

the upper surface of the cylinder block.
Be very careful not to allow any material to accidental
drop into the cylinder block.
Be very careful not to scratch the cylinder block.

2. Carefully remove the oil pump, Rear Seal retainer and

oil pan installation surface seal.

3. Wipe the cylinder block clean.

Cylinder Liner Projection Inspection

1. Hold a straight edge

along the top edge of the

cylinder liner to be measured.

2. Use a feeler gauge

to measure each cylinder line

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

Standard

mm (in)

0.0 - 0.1 (0.0000 - 0.0039)

Flatness

1. Remove the cylinder body dowel.
2. Set the cylinder liner remover to the cylinder liner.
3. Check that the remover shaft ankle is firmly gripping

the cylinder liner bottom edge.

4. Slowly turn the remover shaft handle counterclockwise

to pull the cylinder liner free.
Cylinder Liner Remover Ankle: 5-8840-2304-0 (4JG2)

5-8840-2039-0
(4JB1/4JB1T/4JB1TC)

NOTE:

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

6A-57-1.tif

6A-57-2.tif

6A – 58

GENERAL ENGINE MECHANICAL

5. Use a straight edge

and a feeler gauge

measure the four sides and the two diagonals of the
cylinder body upper face.
If the measured values exceeds the limit, the cylinder
body must be replaced.

Cylinder Liner Bore Measurement

Use a cylinder indicator to measure the cylinder liner bore
at measuring point

in the thrust

and axial

direction of the crankshaft.
Measuring Point

20mm (0.79 in)

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

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.

Cylinder Liner Grade Selection

Measure the cylinder body inside diameter and select the
appropriate cylinder liner grade.
Standard Lifting Interference

mm (in)

0.01 - 0.019 (0.0004 - 0.0007)

If the cylinder liner fitting interference is too small, engine
cooling efficiency will be adversely effected.
If the cylinder liner fitting interference is too large, it will be
difficult to insert the cylinder liner into the cylinder body.

6A-58-1.tif

6A-58-2.tif

6A-58-3.tif

6A-58-4.tif

GENERAL ENGINE MECHANICAL 6A – 59

Cylinder Body Bore Measurement

1) Take measurements at measuring point (A) across

positions

, and

Measuring Point (A) 98mm (3.86 in).
2) Calculate the average value of the four measurements

to determine the correct cylinder grade.

3) Consult the following table with the resultant diameter

for the correct liner application.

Selection method of cylinder liner and piston grade for
service parts.

The production line stamped cylinder liner grade on the
top of cylinder body, the cylinder liner outside diameter
grade 1, 2, 3, 4.
If you find cylinder liner outside diameter grade 1 and
piston outside diameter B on the cylinder body or result of
measurement for each parts, you will select service parts
grade for cylinder liner 1, AX grade and for piston AX
grade.
The stamping grade code on the service parts are;
For cylinder liner grade stamped on the outside of cylinder
liner.
For piston grade stamped on the head of piston.

4JB1 / 4JB1T / 4JB1TC

mm (in)

Liner

outside

Grade

Cylinder bore

diameter average

Liner outside

diameter

Liner

bore

Grade

Service liner bore measurement

93.035 (3.6628) - 93.050 (3.6634)

95.001 - 95.010

(3.7402 - 3.7406)

95.011 - 95.020

(3.7406 - 3.7409)

93.051 (3.6634) - 93.066 (3.6640)

93.035 (3.6628) - 93.050 (3.6634)

95.011 - 95.020

(3.7406 - 3.7409)

95.021 - 95.030

(3.7410 - 3.7413)

93.051 (3.6634) - 93.066 (3.6640)

93.035 (3.6628) - 93.050 (3.6634)

95.021 - 95.030

(3.7410 - 3.7413)

95.031 - 95.040

(3.7414 - 3.7417)

93.051 (3.6634) - 93.066 (3.6640)

93.035 (3.6628) - 93.050 (3.6634)

95.031 - 95.040

(3.7414 - 3.7417)

95.041 - 95.050

(3.7418 - 3.7421)

93.051 (3.6634) - 93.066 (3.6640)

6A-59-1.tif

6A-59-2.tif

Content .. 28 29 30 31 ..