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 1210 of 4264

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".
012RY00010
012LX016
012RY00012
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 1218 of 4264
6A – 78 ENGINE MECHANICAL
Camshaft and Camshaft Bearing Clearance
Use an inside dial indicator to measure the camshaft bearing
inside diameter.
Crankshaft Bearing Inside Diameter mm (in)
Standard Limit
50.00 - 50.03
(1.968 - 1.970) 50.08 (1.972)
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
0.055 (0.0022) 0.12 (0.005)
Camshaft Bearing Replacement
Camshaft Bearing Removal
1. Remove the cylinder body plug plate.
2. Use the bearing replacer to remove the camshaft bearing.
Bearing Replacer: 5-8840-2038-0
Camshaft Bearing Installation
1. Align the bearing oil holes with the cylinder body oil holes.
2. Use the replacer to install the camshaft bearing.
Bearing Replacer: 5-8840-2038-0
014RY00034
014RY00035
014RY00036
Page 1221 of 4264

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
015RY00013 015RY00011
Page 1223 of 4264

ENGINE MECHANICAL 6A – 83
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 crank pin and bearing clearance exceeds the
specified limit, the crankshaft and/or the bearing 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
(0.0011-0.0033) 0.100 (0.0039)
CRANKSHAFT BEARING SELECTION
Crankshaft bearing selection is based on the measured
diameters of the crankshaft journals and the bearing inserts.
Match the crankshaft bearing housing grade marks and the
crankshaft journal grade marks in the table below to determine
the correct crankshaft bearing size.
Crankshaft Bearing Housing Grade Mark
Position
Crankshaft bearing housing grade marks 1, 2 or 3 are stamped
on the rear right hand side of the cylinder body.
Crankshaft Journal Grade Mark Position
The crankshaft journal grade marks (1 or -, 2 or --, 3 or ---) are
stamped on each crankshaft journal web.
The crankshaft journal and bearing clearance must be the
same for each position after installation of the crankshaft and
the crankshaft bearings.
NOTE:
The crankshaft journal mark No. 4 is stamped on
crankshaft No. 4 journal web front side or rear side.
015LX060
015RY00016
Page 1225 of 4264

ENGINE MECHANICAL 6A – 85
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 crankshaft pilot
bearing.
Pilot Bearing Remover: 5-8840-2000-0
Sliding Hammer: 5-8840-0019-0
Crankshaft Pilot Bearing Installation
1. Place the crankshaft pilot bearing right angle 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 race with
the hammer. Do not strike the bearing inner race.
Bearing damage and reduced bearing service life will
result.
FLYWHEEL AND RING GEAR
Flywheel
1. Inspect the flywheel friction surface for excessive wear and
heat cracks.
2. Measure the flywheel friction surface depth.
If the measured value is within 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)
Standard Limit
4JA1T (L),
4JA1TC 20 (0.7874) 21 (0.8267)
4JH1TC 18 (0.7087) 19 (0.7480)
Ring Gear
Inspect the ring gear.
If the ring gear teeth are broken or excessively worn, the ring
gear must be replaced.
015RY00010
015RY00019015RY00018
Page 1226 of 4264

6A – 86 ENGINE MECHANICAL
Ring Gear Replacement
Ring Gear Removal
Strike around the edges of the ring gear with a hammer and
chisel to remove it.
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
200C (390F).
2. Install the ring gear when it is sufficiently heated.
The ring gear must be installed with the chamfer facing the
clutch.
PISTON
Piston Grade Selection and Cylinder Bore
Measurement
Refer to the Section "Cylinder Body", Item "Cylinder Liner Bore
Measurement" for details on piston grade selection and
cylinder liner bore measurement.
Piston Ring Gap
1. Insert the piston ring horizontally (in the position it would
assume if it were installed to the piston) into the cylinder
liner.
2. Push the piston ring into the cylinder bore until it reaches
the measuring point 1 or 2 where the cylinder liner bore is
the smallest.
Do not allow the piston ring to slant to one side or the
other. It must be perfectly horizontal.
Measuring Point 1 10 mm (0.4 in)
or
Measuring Point 2 120 mm (4.7 in)
020LX008
020LX009
015LX023
015RY00020