Page 1195 of 4264
ENGINE MECHANICAL 6A – 55
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.
29. Crankshaft Thrust Bearing
30.Crankshaft
31. 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.
32. 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.
33. Crankshaft Rear Oil Seal
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
34. Cylinder Body
015RY00003
015RY00004
015RY00005
015LV002
Page 1197 of 4264
ENGINE MECHANICAL 6A – 57
CYLINDER HEAD
RTW46ALF001201
Disassembly Steps
1.
Intake manifold 6.
Intake and exhaust valve
2.
Intake manifold gasket 7.
Valve stem oil seal
3.
Split collar 8.
Valve spring lower seat
4.
Valve spring upper seat 9.
Cylinder head
5.
Valve spring
Page 1198 of 4264
6A – 58 ENGINE MECHANICAL
Disassembly
1. Intake Manifold
2. Intake Manifold Gasket
3. Split Collar
1. Place the cylinder head on a flat wooden surface.
2. Use the spring compressor to remove the split collars.
Do not allow the valve to fall from the cylinder head.
Spring Compressor: 9-8523-1423-0
4. Valve Spring Upper Seat
5. Valve Spring
6. 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 the intake and exhaust valves are to be replaced, the
valve guides must also be replaced.
7. Valve Stem Oil Seal
8. Valve Spring Lower Seat
9. Cylinder Head
011RY00011
011LX022
Page 1203 of 4264

ENGINE MECHANICAL 6A – 63
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
Valve Guide Installation
1. Apply engine oil to the valve guide outer circumference.
2. Attach the valve guide installer 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)
12.8-13.2 (0.50-0.52)
NOTE:
If the valve guide has been removed, both the valve
and the valve guide must be replaced as a set.
011LX029
011RY00024
011RY000025011RY00023
Page 1209 of 4264

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.
014RY00024
012R100001
012RY00009014RY00023
Page 1213 of 4264

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".
012RY00017
012RY00018
Page 1215 of 4264

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
014RY00028
Page 1217 of 4264

ENGINE MECHANICAL 6A – 77
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 (1 and 2). 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
(1.9663 - 1.9675) 49.60 (1.953)
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
42.016 (1.6542) 41.65 (1.640)
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)
014RY00032
014RY00033
014LX092