Valve Clearance: Adjustments

Fig. 14 First Valve Clearance Adjustment. Except 16 Valve Engine:

Fig. 15 Second Valve Clearance Adjustment. Except 16 Valve Engine:

EXCEPT 16 VALVE ENGINE

Perform valve adjustment with engine at normal operating temperature.
1. Position No. 1 cylinder to TDC of compression stroke.
2. Turn crankshaft in normal direction of rotation to align timing marks at TDC, then set groove on pulley to the ``0'' position.
3. Ensure rocker arms on No. 1 cylinder are loose and rockers on No. 4 are tight. If not, turn crankshaft one complete revolution and align marks.
4. Adjust valve clearances of the valves shown in Fig. 14, to specification.
5. Turn crankshaft one revolution and align the timing marks.
6. Adjust remaining valves as shown in Fig. 15, to specification.

Fig. 16 First Valve Clearance Adjustment. 16 Valve Engine:

Fig. 17 Second Valve Clearance Adjustment. 16 Valve Engine:

Fig. 18 Depressing Valve Spring. 16 Valve Engine:

Fig. 19 Removing Adjusting Shim. 16 Valve Engine:

Fig. 20 Valve Shim Size Chart. 16 Valve Engine:

16 VALVE ENGINE

Measure and adjust valve clearance while the engine is cold.
1. Disconnect battery ground cable.
2. Remove cylinder head cover.
3. Set No. 1 cylinder at TDC on the compression stroke.
4. Turn crankshaft to align groove in crankshaft pulley with ``0'' mark on No. 1 timing belt cover. Ensure that valve lifters on No. 1 cylinder have freeplay. If not, rotate crankshaft pulley 360° and align the ``0'' mark on timing belt cover.
5. Measure and record valve lash clearance between the cam lobe and the adjusting shim on cylinders shown in Fig. 16.
6. Rotate crankshaft 360° and align groove with ``0'' mark timing belt cover.
7. Measure and record valve lash clearance between the cam lobe and the adjusting shim on cylinders shown in Fig. 17.
8. If clearance is not within specifications, obtain the valve clearance adjustment tool set No. J-37141-A, or equivalent.
9. Insert valve spring compression tool No. J-37141-1, or equivalent, between the camshaft and lifter adjusting shim. This action will compress the valve spring and push lifter down.
10. Insert lifter holding tool No. J-37141-2A, or equivalent, between camshaft and lifter. Position bottom edge of tool on lifter and not on adjusting shim. The lifter appears to be a sleeve around the adjusting shim. This action will hold the lifter away from camshaft, Fig. 18.
11. Remove spring compression tool No. J-37141-1. Lifter holding tool No. J-37141-2A should hold lifter down away from camshaft.
12. Remove adjusting shim with a small screwdriver and magnetic finger, Fig. 19.
13. Measure thickness of removed shim.
14. Calculate thickness of new shim required by using the following formula:
a. T = Thickness of shim removed.
b. A = Valve clearance measured.
c. N = Thickness of shim required.
d. For intake valves use formula; N = T + (A - .008 inch (.20 mm)).
e. For exhaust valves use formula; N = T + (A - .010 inch (.25 mm)).
f. Select a shim from Fig. 20 with a thickness as close as possible to the calculated valve.
15. Install new adjusting shims as required.
16. Depress valve spring using spring compression tool No. J-37141-1 and remove the lifter holding tool No. J-37141-2A.
17. Install cylinder head cover and connect battery ground cable.