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
Page 1227 of 4264

ENGINE MECHANICAL 6A – 87
3. Use a feeler gauge to measure the piston ring gap.
If the measured value exceeds the specified limit, the
piston ring must be replaced.
Piston Ring Gap mm (in)
4JA1T (L), 4JA1TC
Standard Limit
1st Compression Ring
2nd Compression Ring0.3-0.3
(0.0118-0.0197)
Oil Ring 0.250-0.450
(0.0098-0.0177) 1.5
(0.059)
4JH1TC
Standard Limit
1st Compression Ring
2nd Compression Ring0.3-0.5
(0.0118-0.0197)
Oil Ring 0.250-0.450
(0.0098-0.0177) 1.5
(0.059)
Piston Ring and Piston Ring Groove Clearance
Use a feeler gauge to measure the clearance between the
piston ring and the piston ring groove at several points around
the piston.
If the clearance between the piston ring and the piston ring
groove exceeds the specified limit, the piston ring must be
replaced.
Piston Ring and Piston Ring Groove Clearance mm (in)
4JA1T (L), 4JA1TC
Standard Limit
1st Compression Ring0.09-0.125
(0.0035-0.0049)
2nd Compression Ring0.05-0.085
(0.0020-0.0033)
Oil Ring 0.03-0.070
(0.0012-0.0028) 0.15
(0.0059)
4JH1TC
Standard Limit
1st Compression Ring0.09-0.130
(0.0035-0.0051)
2nd Compression Ring0.05-0.090
(0.0020-0.0035)
Oil Ring 0.03-0.070
(0.0012-0.0028) 0.15
(0.0059)
015RY00021
015LX025
Page 1228 of 4264

6A – 88 ENGINE MECHANICAL
4. Visually inspect the piston rings.
If a piston ring groove is damaged or distorted, the piston
must be replaced.
Piston Pin Diameter
Use a micrometer to measure the piston pin diameter at
several points.
If the measured value is less than the specified limit, the piston
pin must be replaced.
Piston Pin Diameter mm (in)
Standard Limit
30.995-31.000
(1.2202-1.2204) 30.97
(1.2193)
Piston Pin and Piston Clearance
Use and inside dial indicator to measure the piston pin hole (in
the piston).
Piston Pin Hole mm (in)
4JA1T (L) 31.002-31.010 (1.2206-1.2208)
4JA1TC, 4JH1TC 31.005-31.013 (1.2207-1.2210)
Piston Pin and Piston Pin Hole Clearance mm (in)
4JA1T (L) 0.002-0.015 (0.00008-0.0006)
4JA1TC, 4JH1TC 0.005-0.018 (0.0002-0.0007)
CYLINDER HEAD GASKET SELECTION
Cylinder head gasket is determined by the piston head
projection from the cylinder body upper surface, in order to
improve engine performance.
Three types of gasket are provided by the difference of
thickness. Select the adequet one out of three grades of
gasket, according to the following procedure.
Before measurement, clear off carbon from the piston head
and cylinder body surface and also clean the place where a
gasket was installed.
015LX026
015RW048
011LX011
Page 1229 of 4264

ENGINE MECHANICAL 6A – 89
RTW36ASH001701
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 1, 2, 3, 4 and obtain two differences 1-
2 and 3-4 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)
Cylinder Head Gasket Combination
4JA1T (L), 4JA1TC mm (in)
Gasket Grade Mark Piston Projection Gasket Thickness
(Reference)
A 0.718-0.773
(0.0283-0.0304) 1.6
(0.0630)
B 0.773-0.819
(0.0304-0.0322) 1.65
(0.0650)
C 0.819-0.874
(0.0322-0.0344) 1.70
(0.0669)
4JH1TC 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)
NOTE:
Difference of the each piston projection and must be
equal or within 0.1 mm (0.004 in).
011RY00027
011RY00030
Page 1230 of 4264

6A – 90 ENGINE MECHANICAL
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 (0.003) or Less 0.20 (0.008)
Parallelism 0.05 (0.002) or Less 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)
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.
Piston Pin and Connecting Rod Small End
Bushing Clearance
mm (in)
Standard Limit
4JA1T (L) 0.008-0.020
(0.003-0.0008) 0.050 (0.002)
4JA1TC,
4JH1TC 0.005-0.018
(0.0002-0.0007) 0.050 (0.002)
015LX034
011RY00029
015LX028
Page 1231 of 4264

ENGINE MECHANICAL 6A – 91
IDLER GEAR SHAFT AND IDLER GEAR
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
(1.7695-1.7707) 44.845 (1.755)
Idler Gear "A" Shaft inside Diameter
1. Use an inside dial indicator or an inside micrometer to
measure the idler gear inside diameter.
Idler Gear Inside Diameter mm (in)
Standard Limit
45.0-45.03
(1.7717-1.7718) 45.10 (1.7756)
If the clearance between the idler gear shaft outside diameter
and the idler gear inside diameter exceeds the limit, the idler
gear must be replaced.
Idler Gear Shaft and Idler Gear Clearance mm (in)
Standard Limit
0.025-0.085
(0.0010-0.0033) 0.200 (0.0079)
TIMING GEAR CASE COVER
Replace the crankshaft front oil seal if it is excessively worn or
damaged.
Crankshaft Front Oil Seal Replacement
Oil Seal Removal
Use a plastic hammer and a screwdriver to tap around the oil
seal to free it from the gear case cover.
Take care not to damage the oil seal lip surfaces.
020RY00025
014LX022
020R300004
Page 1232 of 4264
6A – 92 ENGINE MECHANICAL
Oil Seal Installation
Use the special tool to install the front oil seal.
Front Oil Seal Installer: 5-8840-2361-0
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 = 1.0 0.03mm
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.
020R300005