Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual — part 567

6A – 106 ENGINE MECHANICAL

Piston Head Projection Measuring Point

1. Use a dial indicator to measure the piston projection

amount.

2. Refer to the illustration for the piston head projection

measuring positions.
All measuring positions should be as close as possible
to the cylinder liner.

3. Measure

the

points

Q

R

S

T

and obtain two

differences

Q

–

R

and

S

–

T

on each cylinder.

Calculate the average value of the piston head
projection on each cylinder.

4. Obtain the maximum value in the four cylinders.
5. Determine the gasket grade required to the maximum

value described above in accordance with the following
table.

Cylinder Head Gasket Combination

mm (in)

Piston Projection

Gasket Grade
Mark

4JA1, 4JA1TC

4JB1T

Gasket

Thickness

(Reference)

A

0.718 – 0.773

(0.0283 – 0.0304)

0.758 – 0.813

(0.0298 – 0.0320)

1.6

(0.0630)

B

0.773 – 0.819

(0.0304 – 0.0322)

0.813 – 0.859

(0.0320 – 0.0338)

1.65

(0.0650)

C

0.819 – 0.874

(0.0322 – 0.0344)

0.859 – 0.914

(0.0338 – 0.0360)

1.70

(0.0669)

4JH1TC Cylinder Head Gasket Thickness mm (in)

Gasket Grade
Mark

Piston Projection

Gasket Thickness

(Reference)

A

0.215 – 0.265

(0.0085 – 0.0104)

1.3

(0.5118)

B

0.265 – 0.315

(0.0104 – 0.0124)

1.35

(0.5315)

C

0.315 – 0.365

(0.0124 – 0.0144)

1.4

(0.5512)

For 4JA1/4JA1T/4JB1T/4JA1TC/4JH1TC

ENGINE MECHANICAL 6A – 107

4JG2T Cylinder Head Gasket Combination mm (in)

Gasket Grade

Mark

Piston Projection

Gasket Thickness

(Reference)

A

0.658 – 0.712

(0.0259 – 0.0281)

1.6

(0.0630)

B

0.713 – 0.758

(0.0281 – 0.0299)

1.65

(0.0650)

C

0.759 – 0.813

(0.0299 – 0.0320)

1.70

(0.0669)

Note:
Difference of the each piston projection and must be
equal or within 0.1 mm (0.004 in).

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

0.08 or Less (0.003)

0.20 (0.008)

Parallelism

0.05 or Less (0.002)

0.15 (0.006)

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 Big End and Crankpin Side
Face Clearance

mm (in)

Standard Limit

0.23 (0.009)

0.35 (0.014)

011RY00031

For 4JG2T

6A – 108 ENGINE MECHANICAL

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

(0.0003 – 0.0008)

0.050 (0.002)

Connecting Rod Bushing Replacement

Connecting Rod Bushing Removal

1. Set the connecting rod small end to the bench press

V-block

Q

.

2. Use the bench press

R

and the bar

S

to slowly force

the bushing from the connecting rod

T

.

Note:
Take care not to damage the connecting rod with the
bar when removing the bushing.

Connecting Rod Bushing Installation

1. Set the connecting rod small end

Q

to the bench

press V-block.
The connecting rod must be perfectly horizontal.

2. Use the bench press

R

and the bar

S

to slowly force

the bushing with oil hole into position.

3. Use a pin hole grinder

T

fitted with a reamer

U

to

ream the piston pin hole.

ENGINE MECHANICAL 6A – 109

TIMING PULLEY HOUSING

Replace the crankshaft front oil seal if it is worn or
damaged.
Take care not to damage the oil seal fitting surfaces.

Crankshaft Front Oil Seal Replacement

Oil Seal Removal

With the oil seal pushed in deep, install the special tool as
shown in the illustration and remove the oil seal.
Oil Seal Remover: 5-8840-2362-0
Note:
Take care not to damage sealing surface of front plate
and crankshaft when removing oil seal.

Oil Seal Installation

Use the special tool to install the oil seal.
1. With the oil seal attached to the sleeve, insert it into

the front end section of the crankshaft.

2. With the oil seal end section attached securely to the

crankshaft, tighten up the center bolt until the sleeve
hits the front end reference plane of the crankshaft
securely.

3. Remove

the

sleeve.

4. With the seal pressed in, check the dimension of the

oil seal section.
Standard Dimension = 0.9

± 0.3 mm

Note:
Install the oil seal after assembling the timing pulley
housing. The oil seal lip section is applied with oil.
Take notice of the press-in direction of the oil seal.

Front Oil Seal Installer: 5-8840-2361-0

IDLER GEAR SHAFT AND IDLER GEAR
(GEAR Drive Model)

Idler Gear “A” 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 shaft must be replaced.
Idler Gear “A” Shaft Outside Diameter

mm (in)

Standard Limit

44.945 – 44.975

(1.769 – 1.770)

44.845 (1.766)