LEXUS LS430 2003 Factory Repair Manual

Standard overall length:
94.80 to 95.30 mm (3.7323 to 3.7520 in.)
Minimum overall length: 94.55 mm (3.7224 in.)
If the overall length is less than the minimum, replace the valve.
Fig. 327: Checking Surface Of Valve Stem

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
f. Check the surface of the valve stem tip for wear.
If the valve stem tip is worn, resurface the tip with a grinder or replace the valve.

Fig. 328: Checking Exhaust Valve
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
7.INSPECT EXHAUST VALVE
a. Clean the valves.
1. Using a gasket scraper, chip off any carbon from the valve head.
2. Usin
g a wire brush, thoroughly clean the valve.

Fig. 329: Measuring Diameter Of Valve Stem Using Micrometer
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
b. Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter:
5.465 to 5.480 mm (0.2152 to 2.2157 in.)
If the clearance is
greater than the maximum, replace the valve and guide bushing.

Fig. 330: Removing Pits And Carbon
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
c. Check the valve face angle.
1. Grind the valve enough to remove pits and carbon.
2. Check that the valve is ground to the correct valve face angle.
Valve face angle: 44.5°
If the valve face is worn, replace the valve.

Fig. 331: Measuring Valve Head Margin Thickness
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
d. Check the valve head margin thickness.
Standard margin thickness: 1.0 mm (0.039 in.)
Minimum margin thickness: 0.5 mm (0.020 in.)
If the mar
gin thickness is less than the minimum, replace the valve.

Fig. 332: Checking Valve Overall Length
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
e. Check the valve overall len
gth.

Standard overall length:
94.85 to 95.35 mm (3.7342 to 3.7539 in.)
Minimum overall length: 94.60 mm (3.7244 in.)
If the overall length is less than the minimum, replace the valve.
Fig. 333: Checking Surface Of Valve Stem Tip For Wear

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
f. Check the surface of the valve stem tip for wear.
If the valve stem tip is worn, resurface the tip with a grinder or replace the valve.

Fig. 334: Measuring Deviation Of Spring Using Steel Squares
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
8.INSPECT INNER COMPRESSION SPRING
a. Using steel squares, measure the deviation of the spring.
Maximum deviation: 2.0 mm (0.079 in.)
If the deviation is
greater than the maximum, replace the spring.

Fig. 335: Measuring Free Length Of Spring Using Vernier Caliper
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
b. Using a vernier caliper, measure the free length of the spring.
Free length: 54.05 to 54.15 mm (2.1279 to 2.1319 in.)
If the free len
gth is not as specified, replace the spring.