Contents: Checking valve drive clearances ↓ Adjusting valve clearances ↓ Example calculation (intake valves) ↓
Checking valve drive clearances
Remove the cylinder head cover.
Set the piston of cylinder No.1 to TDC of the compression stroke.
Fig. 2.118. Valves to be tested
Check the valves shown in Figure 2.118.
Using a set of flat feeler gauges, measure the clearances between the valve lifters and the camshaft lobes.
Valve clearance (cold engine): 0.15–0.25 mm for intake valves, 0.25–0.35 mm for exhaust valves.
The original text is posted on ToyotaMan.ru
Record any valve clearance measurements that are not within specifications. These will be needed later to determine the dimensions of the replacement valve lifters.
Turn the crankshaft 1 revolution (360°) and set the piston of cylinder No.4 to TDC of the compression stroke.
Fig. 2.119. Valves to be tested
Check the valves shown in Figure 2.119.
Using a set of feeler gauges, measure the clearances between the valve lifters and the camshaft lobes.
Valve clearance (cold engine): 0.15–0.25 mm for intake valves, 0.25–0.35 mm for exhaust valves.
Record any valve clearance measurements that are not within specifications. These will be needed later to determine the dimensions of the replacement valve lifters.
Adjusting valve clearances
Remove camshaft No.2.
Remove the camshaft.
Fig. 2.120. Measuring the thickness of the valve tappet
Use a micrometer to measure the thickness of the removed valve lifters (fig. 2.120)
Calculate the thickness of the new valve lifter so that the valve clearance matches the specified value.
Valve drive clearances:
- inlet valves A=B+(C–0.20 mm).
- exhaust valves A=B+(C–0.30 mm).
Example calculation (intake valves)
Measured clearance in the intake valve drive = 0.40 mm.
0.40 mm – 0.20 mm = 0.20 mm.
(Measured – Nominal = Excess Clearance).
Measured thickness of removed tappet = 5.250 mm.
0.20 mm + 5.250 mm = 5.450 mm.
(Excess clearance + Thickness of removed tappet = Thickness of new tappet).
The most suitable thickness of the new tappet = 5.460 mm.
Select pusher #46.
Note: Select a new valve lifter whose thickness is closest to the calculated value.
Note: Valve adjuster tappets are available in 35 sizes in 0.020mm increments, from 5.060mm to 5.740mm.
Install the camshaft.
Install camshaft #2.
The installation of the remaining components is carried out in the reverse order of removal.