LEXUS LS430 2003 Factory Repair Manual

HINT:
Use a new cylinder block:
Use a piston with the same number mark as the cylinder diameter marked on the cylinder
block.
The shape of the piston varies for the LH and RH banks. The LH piston is marked with "3L"
and the RH piston is marked with "3R".

Fig. 443: Identifying Cylinder Block Diameter
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
c. Inspect the piston pin fit.

1. At 60°C (140°F), check that the piston pin can be pushed into the piston pin hole with your
thumb.
Fig. 444: Checking Piston Pin

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
d. Using a micrometer, measure the piston pin diameter.
Piston pin diameter:
21.997 to 22.006 mm (0.8660 to 0.8664 in.)

Fig. 445: Measuring Piston Pin Diameter Using Micrometer
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
10.INSPECT PISTON RING SET
a. Inspect the piston ring groove clearance.
1. Using a feeler gauge, measure the clearance between a new piston ring and the wall of the
ring groove.
RING GROOVE CLEARANCE:
RING GROOVE CLEARANCE SPECIFICATIONS
If the clearance is not as specified, replace the piston.
No. 10.030 to 0.080 mm (0.0012 to 0.0031 in.)
No. 20.020 to 0.060 mm (0.0008 to 0.0024 in.)

Fig. 446: Measuring Clearance Between Piston Ring Using Feeler Gauge
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
b. Inspect the piston ring end gap.
1. Insert the piston ring into the cylinder bore.
2. Using a piston, push the piston ring a little beyond the bottom of the ring travel 105 mm (4.13 in.)
from the top of the cylinder block.

Fig. 447: Inserting Piston Ring Into Cylinder Bore
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
3. Using a feeler gauge, measure the end gap.
STANDARD END GAP:
END GAP SPECIFICATIONS

MAXIMUM END GAP:
MAXIMUM END GAP SPECIFICATIONS
Fig. 448: Measuring Piston Ring Gap Using Feeler Gauge

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
If the end gap is greater than the maximum, replace the piston ring. If the end gap is greater than the
maximum, even with a new piston ring, replace the cylinder block sub-assy.
No. 10.300 to 0.500 mm (0.0118 to 0.0197 in.)
No. 20.400 to 0.600 mm (0.0157 to 0.0236 in.)
Oil (Side rail)0.150 to 0.500 mm (0.0059 to 0.0197 in.)
No. 11.05 mm (0.0413 in.)
No. 21.20 mm (0.0472 in.)
Oil (Side rail)1.10 mm (0.0433 in.)

11.INSPECT CONNECTING ROD SUB-ASSY
a. Using a rod aligner and feeler gauge, check the connecting rod alignment.
1. Check if it is bent.
Maximum bend:
0.05 mm (0.0020 in.) per 100 mm (3.94 in.)
If the bend is greater than the maximum, replace the connecting rod sub-assy.
Fig. 449: Checking Connecting Rod Alignment

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2. Check if it is twisted.
Maximum twist:
0.15 mm (0.0059 in.) per 100 mm (3.94 in.)
If the twist is
greater than the maximum, replace the connecting rod sub-assy.

Fig. 450: Checking Twisted
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
12.INSPECT PISTON PIN OIL CLEARANCE
a. Inspect the piston pin oil clearance.
1. Using a caliper gauge, measure the inside diameter of the connecting rod bushing.
Bushing inside diameter:
22.005 to 22.014 mm (0.8663 to 0.8667 in.)
If the bushing inside diameter is not as specified, check the oil clearance.
2. Subtract the piston pin diameter measurement (see step 10) from the bush inside diameter
measurement.

Fig. 451: Measuring Inside Diameter Of Connecting Rod Bushing Using Caliper Gauge
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard oil clearance:
0.005 to 0.011 mm (0.0002 to 0.0004 in.)
Maximum oil clearance: 0.05 mm (0.0020 in.)
If the oil clearance is greater than the maximum, replace the bush. If necessary, replace the piston and
piston pin with a new piston and pin set.
13.REMOVE CONNECTING ROD SMALL END BUSH
a. Using SST and a press, press out the bush.
SST 09222-30010