LEXUS LS430 2003 Factory Repair Manual

Fig. 346: Identifying Specification Clearance Using Reamer
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
e. Using a sharp 5.5 mm reamer, ream the guide bush to obtain the standard specified clearance (see
step 9) between the guide bush and valve stem.

Fig. 347: Measuring Bush Bore Diameter Of Cylinder Head Using Caliper
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
14.INSTALL EXHAUST VALVE GUIDE BUSH
a. Using a caliper gauge, measure the bush bore diameter of the cylinder head.
b. Select a new guide bush (STD or O/S 0.05).
GUIDE BUSH REFERENCE
If the bush bore diameter of the cylinder head is greater than 10.306 mm (0.4057 in.), machine the
bush bore diameter to between 10.335 and 10.356 mm (0.4068 to 0.4077 in.)
If the bush bore diameter of the cylinder head is greater than 10.356 mm (0.4077 in.), replace the
cylinder head.
HINT:
Bush sizeBush bore diameter
Use STD10.285 to 10.306 mm (0.4049 to 0.4057 in.)
Use O/S 0.0510.335 to 10.356 mm (0.4068 to 0.4077 in.)

Different the bushes are used for the intake and exhaust.
Bush length: 40.5 mm (1.594 in.)
Fig. 348: Identifying Intake And Exhaust Bush Dimension

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
c. Gradually heat the cylinder head to approximately 80 to 100 °C (176 to 212°F).
d. Using SST and a hammer, tap in a new guide bush to the specified protrusion height.
SST 09201-01055 (09951-07100), 09950-70010
<0033005500520057005500580056004c005200510003004b0048004c004a004b00570003000b002b000c001d0003001b001100150003005700520003001b0011001b0003005000500003000b00130011001600150016000300570052000300130011001600
1700190003004c00510011000c[

Fig. 349: Taping Guide Bush Using SST And Hammer
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
e. Using a sharp 5.5 mm reamer, ream the guide bush to obtain the standard specified clearance (see
step 10) between the
guide bush and valve stem.

Fig. 350: Identifying Specification Clearance Using Reamer
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
15.INSPECT INTAKE VALVE SEAT
a. Usin
g a 45° carbide cutter, resurface the valve seats. Remove only enough metal to clean the seats.

Fig. 351: Checking Intake Valve Seat Identify
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
b. Check the valve seating position.
1. Apply a light coat of Prussian blue (or white lead) to the valve face.
2. Lightly press the valve against the seat. Do not rotate the valve.
c. Check the valve face and seat for the following:
1. If blue appears 360° around the face, the valve is concentric. If not, replace the valve.

Fig. 352: Checking Valve Seating Position
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2. If blue appears 360° around the valve seat, the guide and face are concentric. If not, resurface
the seat.
3. Check that the seat contact is in the middle of the valve face and has the width below.
Width: 1.0 to 1.4 mm (0.039 to 0.055 in.)

Fig. 353: Checking Seat Contact Surface (1 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
If not, correct the intake valve seats as follows:
d. If the seating is too high on the valve face: Use 30° and 45° cutters to correct the seat.
e. If the seatin
g is too low on the valve face: Use 60° and 45° cutters to correct the seat.

Fig. 354: Checking Seat Contact Surface (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
f. Handrub the valve and valve seat with an abrasive compound.
g. After handrubbing, clean the valve and valve seat.

Fig. 355: Cleaning Valve And Valve Seat
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
16.INSPECT EXHAUST VALVE SEAT
a. Using a 45° carbide cutter, resurface the valve seats. Remove only enough metal to clean the seats.