Camshaft (EXH) Valve Clearance Adjustment
- Perform adjustment depending on selected head thickness of valve lifter (EXH).
- Measure the valve clearance. Refer to Inspection .
- Remove VVEL ladder assembly and camshaft (EXH). Refer to Disassembly and Assembly .CAUTION: Never loosen adjusting bolts and mounting bolts (black color) of VVEL ladder assembly.
- Remove valve lifter (EXH) at the locations that are out of the standard.
- Measure the center thickness of the removed valve lifters (EXH) with a micrometer (A).
- Use the equation below to calculate valve lifter (EXH) thickness for replacement.
Valve lifter (EXH) thickness calculation:
t = t 1 + (C 1 - C 2 )
t
= Valve lifter (EXH) thickness to be replaced
t 1
= Removed valve lifter (EXH) thickness
C 1
= Measured valve clearance
C 2
= Standard valve clearance:
Exhaust
: 0.33 mm (0.013 in)
- Thickness of new valve lifter (EXH) can be identified by stamp marks on the reverse side (inside the cylinder).
Stamp mark 788 indicates 7.88 mm (0.3102 in) in thickness.
A
: Stamp
B
: Thickness of valve lifter (EXH)
Available thickness of valve lifter (EXH): 27 sizes with range 7.88 to 8.40 mm (0.3102 to 0.3307 in) in steps of 0.02 mm (0.0008 in) (when manufactured at factory). Refer to Camshaft .
- Thickness of new valve lifter (EXH) can be identified by stamp marks on the reverse side (inside the cylinder).
- Install selected valve lifter (EXH).
- Install VVEL ladder assembly and camshaft (EXH). Refer to Disassembly and Assembly .
- Manually turn crankshaft pulley a few turns.
- Check that the valve clearances for cold engine are within the specifications by referring to the specified values. Refer to Inspection .
- Install all removed parts in the reverse order of removal.
- Warm up the engine, and check for unusual noise and vibration.