The valve stem-to-rocker arm clearance for all engines except the 3.0L and the 3.2L SHO should be within specification with the valve lifter completely collapsed. To determine the rocker arm-to-valve lifter clearance, make the following checks:
See Figure 1
- Set the No. 1 piston on TDC of the compression stroke. The timing marks on the camshaft and crankshaft gears will be together. Check the clearance in the No. 1 intake, No. 1 exhaust, No. 2 intake and No. 3 exhaust valves.
- Rotate the crankshaft 1 complete turn (360°), or 180° for the camshaft gear. Check the clearance on the No. 2 exhaust, No. 3 intake, No. 4 intake and No. 4 exhaust valves.
- The clearance between the rocker arm and the valve stem tip should be 0.071-0.170 in. (1.80-4.34mm) with the lifter on the base circle of the cam.
fz 3.0L AND 3.8l ENGINE-EXCEPT SHO
See Figures 2 and 3
Rotate the engine until the No. 1 cylinder is at TDC of its compression stroke and check the clearance between the following valves:
- No. 1 intake and No. 1 exhaust valves
- No. 3 intake and No. 2 exhaust valves
- No. 6 intake and No. 4 exhaust valves
Rotate the crankshaft 360° and check the clearance between the rocker arm and the following valves:
- No. 2 intake and No. 3 exhaust valves
- No. 4 intake and No. 5 exhaust valves
- No. 5 intake and No. 6 exhaust valves
- The clearance should be 0.085-0.185 in. (2.15-4.69mm) for the 3.0L engine and 0.089-0.189 in. (2.25-4.79mm) for the 3.8L engine.
3.0L AND 3.2L SHO ENGINES
See Figure 4
- Disconnect the negative battery cable.
- Remove the valve cover. For the 3.2L SHO engine, first remove the EGR valve-to-exhaust manifold tube to gain access to the right-hand valve cover. For details regarding these procedures, please refer to Engine & Engine Overhaul .
- Remove the intake manifold assembly. For details regarding this procedure, please refer to Engine & Engine Overhaul .
- Insert a feeler gauge under the cam lob at a 90° angle to the camshaft. Clearance for the intake valves should be 0.006-0.010 in. (0.15-0.25mm). Clearance for the exhaust valves should be 0.010-0.014 in. (0.25-0.35mm).
The cam lobes must be directed 90° or more away from the valve lifters/tappets.