Valve Clearance: Notes
Bring camshaft into correct position for checking valves. Using a suitable go and no-go feeler gauge, check that clearance between valve tappet and heel of cam is to specifications given under "Preliminary Check." If within specifications, no further adjustment is necessary. If not, proceed as follows:
NOTE:
Turbo valve clearances are critical. Use only specifications listed for Turbo.
- Using special tool (8391450) and a dial indicator, measure clearance of each valve. With measuring point of dial indicator resting on tip of cam, zero dial indicator.
- Lift valve depressor with special tool and note movement of dial indicator, indicating present valve clearance. Any valve not within "Adjustment Limit" specifications should be adjusted as follows:
- Remove camshaft, valve depressors and adjusting pads of valves needing adjustment. Measure thickness of adjusting pad with special tool (8391633) and calculate thickness of new pad required to bring valve clearance within "Adjustment Limit" specifications.
- Measured valve clearance plus adjusting pad thickness equals total distance between valve and cam. This total distance less the specified valve clearance, determines thickness of new adjusting pad to be installed.
- Install new adjusting pad, valve depressors, and camshaft and recheck that clearances are correct.
Valve Clearances(1)
| Application | Clearance | ||
|---|---|---|---|
| Preliminary Check | |||
| Intake | .006-.012" (.15-.30 mm) | ||
| Exhaust | |||
| All Exc. Turbo | .014-.020" (.35-.50 mm) | ||
| Turbo | .016-.020" (.40-.50 mm) | ||
| Adjustment Limit | |||
| Intake | .008-.010" (.20-.25 mm) | ||
| Exhaust | |||
| All Exc. Turbo | .016-.018" (.40-.45 mm) | ||
| Turbo | .018-.020" (.45-.50 mm) | ||
| (1) - When checked 30 minutes after driving vehicle at normal operating temperature. | |||