4JH1 ISUZU KB P190 2007 Workshop Service Manual

ENGINE MECHANICAL 6A – 69
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".
















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.
If the measured values exceeds the limit, the cylinder body
must be replaced.

Cylinder Body Upper Face Warpage mm (in)
Standard Limit
0.05 (0.002) or less 0.20 (0.008)


Cylinder Body Height (H) (Reference) mm (in)
Standard
4JA1T(L), 4JA1TC : 244.945-245.055 (9.6435-9.6478)
4JH1TC : 269.945-270.055 (10.6277-10.6320)
4. Reinstall the cylinder liner. Refer to "Cylinder Liner Replacement".
5. Reinstall the cylinder body dowel.


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6A – 70 ENGINE MECHANICAL





















Cylinder Liner Bore Measurement
Use a cylinder indicator to measure the cylinder bore at
measuring point (1) in the thrust (2-2) and axial (3-3) directions
of the crankshaft.
Measuring Point (1): 20 mm (0.79 in)
If the measured value exceeds the specified limit, the cylinder
liner must be replaced.


Cylinder Liner Bore mm (in)
Standard Limit
4JA1T(L), 4JA1TC 93.00 (3.6614) 93.08 (3.6646)
4JH1TC 95.40 (3.7559) 95.48 (3.7590)
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 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 liner projection.

Cylinder Liner Projection mm (in)
Standard
0-0.1 (0-0.004)
The difference in the cylinder liner projection height
between any two adjacent cylinders must not exceed 0.03
mm (0.0012 in).












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) until it makes firm
contact with the cylinder liner.
Cylinder Liner Remover : 5-8840-2039-0 (4JA1L/TC)
: 5-8840-2304-0 (4JH1TC)
2. Use a bench press (2) to slowly force the cylinder liner from the cylinder body.


NOTE:
Take care not to damage the cylinder body upper face
during the cylinder liner removal procedure.
3. Measure the cylinder body upper face warpage. Refer to "Cylinder Body Upper Face Warpage".
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ENGINE MECHANICAL 6A – 71











Cylinder Liner Grade Selection
Subtract the average cylinder body bore from the average
cylinder liner outside diameter to obtain the fitting interference.

Fitting Interference mm
(in)
Standard
-0.0010*-0.019 (-0.00004*-0.0007)
* A minus (-) value indicates that the cylinder body bore is
smaller than the liner outside diameter.



Cylinder Body Bore Measurement
1. Take measurements at measuring point (1) across positions 1-1 and 2-2.
Measuring Point (1):
4JA1T(L), 4JA1TC : 13,48,83,118,153 mm
(0.51,1.89,3.27,4.65,6.02 in)
4JH1TC : 18,53,88,123,158 mm (0.71,2.09,3.46,4.84,6.22
in)





Cylinder Liner Grade Selection and Standard
Fitting Interference
Accurately measured fitting interference and proper cylinder
liner grade selection are extremely important.
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.
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6A – 72 ENGINE MECHANICAL


012RY00022
A mark was stamped on the upper side of the cylinder block
during production to indicate the correct liner.
The liner grade (i.e.1.2.3.4) is indicated in metal stamp.


Cylinder Liner Grade
4JA1T (L), 4JA1TC mm (in)
Liner
Outside Grade Cylinder Body
Bore Diameter Liner Outside
Diameter Liner Bore
Grade Service Liner Bore Measurement
AX 93.035-93.050 (3.6628-3.6634) 1 95.001-95.010
(3.7402-3.7405) 95.011-95.020
(3.7406-3.7409) CX 93.051-93.066 (3.6634-3.6640)
AX 93.035-93.050 (3.6628-3.6634) 2 95.011-95.020
(3.7406-3.7409) 95.021-95.030
(3.7410-3.7413) CX 93.051-93.066 (3.6634-3.6640)
AX 95.035-93.050 (3.6628-3.6634) 3 95.021-95.030
(3.7410-3.7413) 95.031-95.040
(3.7414-3.7417) CX 93.051-93.066 (3.6634-3.6640)
AX 93.035-93.050 (3.6628-3.6634) 4 95.031-95.040
(3.7414-3.7417) 95.041-95.050
(3.7418-3.7421) CX 93.051-93.066 (3.6634-3.6640)
4JH1TC mm (in)
Liner
Outside Grade Cylinder Body
Bore Diameter Liner Outside
Diameter Liner Bore
Grade Service Liner Bore Measurement
AX 95.435-95.450 (3.7573-3.7579) 1 97.001-97.010
(3.8189-3.8193) 97.011-97.020
(3.8193-3.8197) CX 95.451-95.466 (3.7579-3.7585)
AX 95.435-95.450 (3.7573-3.7579) 2 97.011-97.020
(3.8193-3.8197) 97.021-97.030
(3.8197-3.8200) CX 95.451-95.466 (3.7579-3.7585)
AX 95.435-95.450 (3.7573-3.7579) 3 97.021-97.030
(3.8197-3.8200) 97.031-97.040
(3.8200-3.8205) CX 95.451-95.466 (3.7579-3.7585)
AX 95.435-95.450 (3.7573-3.7579) 4 97.031-97.040
(3.8200-3.8205) 97.041-97.050
(3.8205-3.8209) CX 95.451-95.466 (3.7579-3.7585)

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ENGINE MECHANICAL 6A – 73






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.










4. Set the cylinder liner installer (3) to the top of the
cylinder liner.
Cylinder Liner Installer : 5-8840-2040-0 (4JA1L/TC)
: 5-8840-2313-0 (4JH1TC)
5. (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 4,900 N (500 kg/1,100 Ib) to the cylinder liner.
7. Apply a force of 24,500 N (2,500 kg/5,500 Ib) to fully seat the cylinder liner.
8. After installing the cylinder liner, measure the cylinder liner projection.
Refer to "Cylinder Liner Projection Inspection".

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6A – 74 ENGINE MECHANICAL










Piston Grade Selection
Measure the cylinder liner bore after installing the cylinder liner.
Then select the appropriate piston grade for the installed
cylinder liner.
1. Measure the cylinder liner bore. Refer to "Cylinder Liner Bore Measurement"

Cylinder Liner Bore (Service Part) Grade mm (in)
Grade Bore measurement
AX 93.035-95.050
(3.6628-3.6634) 4JA1T(L) 4JA1TC CX 93.051-95.066
(3.6634-3.6640)
AX 95.435-95.450
(3.7573-3.7579)
4JH1TC
CX 95.451-95.466
(3.7579-3.7585)

NOTE:
It is most important that the correct piston grade be
used. Failure to select the correct piston grade will
result in engine failure. Always measure the cylinder
bore and select the correct piston grade.

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ENGINE MECHANICAL 6A – 75










































2. Measure the piston diameter.

Piston Measuring Point mm (in)
4JA1T(L) 4JA1TC 78 (3.07)
4JH1TC 70
(2.76)


Piston Grade (Service Part) mm (in)
AX 92.949 - 92.964
(3.6549 - 3.6600)
4JA1T(L) 4JA1TC CX 92.965 - 92.980
(3.6600 - 3.6606)
AX 95.359 - 95.374
(3.7542 - 3.7548)
4JH1TC
CX 95.375 - 95.390
(3.7548 - 3.7555)


Cylinder Liner and Piston Clearance mm (in)
4JA1T(L) 4JA1TC 0.041-0.071 (0.0016-0.0027)
4JH1TC 0.047-0.065
(0.0019-0.0026)

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.



TAPPET AND PUSH ROD
Visually inspect the tappet 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. Normal contact
2. Cracking
3. Pitting
4. Irregular contact Uneven contact
5. Irregular contact One-sided 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.


015LX021
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ENGINE MECHANICAL 6A – 79




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.
Therefore, under size bearing are not available.























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 (0.003)















Bearing Spread
Use a vernier caliper to measure the bearing spread.
If the measured value is less than the specified limit, the
bearing must be replaced.

Bearing Spread mm
(in)
Limit
4JA1T (L), 4JA1TC 64.5 (2.54)
Creankshaft Bearing
4JH1TC 74.5 (2.93)
Connecting Rod Bearing 56.5 (2.22)


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6A – 80 ENGINE MECHANICAL

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 specified limit, the
crankshaft must be replaced.

Crankshaft Journal and Diameter mm (in)
Standard Limit
4JA1T (L),
4JA1TC 59.921-59.928
(2.3591-2.3594) 59.91 (2.3586)
4JH1TC
69.917-69.932
(2.7526-2.7532) 69.91(2.7524)


Crankpin Diameter mm
(in)
Standard Limit
52.915 - 52.930
(2.0833 - 2.0839) 52.90 (2.083)



Crankshaft Journal and Crankpin Uneven W ear mm (in)
Standard Limit
0.05 (0.002) or less
0.08 (0.003)


Crankshaft Journal and Crankpin Diameter
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 Journal and Bearing Clearance mm (in)
Standard Limit
0.032 - 0.077
(0.0013 - 0.0030) 0.110 (0.0043)



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ENGINE MECHANICAL 6A – 81

Connecting Rod Bearing Inside Diameter
1. Install the bearing to the connecting rod big end.
2. Tighten the bearing cap to the two step of anglar tightening method.

Connecting Rod Bearing Cap Bolt Torque
N·m (kg·m/Ib ft)
4JA1T (L), 4JA1TC 78-88 (8.0/57 – 9.0/65)
1st step ; 29.0–29.2 (3.00/22.0–3.01/22.2)4JH1TC
2nd step ; 45°-60 °
3. Use an inside dial indicator to measure the connecting rod
bearing inside diameter.



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
4JA1T (L),
4JA1TC 0.029-0.066
(0.0011-0.0026) 0.100(0.0039)
4JH1TC
0.029-0.083
(0.0011-0.033) 0.100 (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 mm (in)
167 (17/123)
Do not allow the crankshaft to turn during bearing cap
installation and tightening.
8. Remove the bearing cap.


015RY00012
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