Rocker Arm Assembly: Service and Repair

Fig. 6 Locking The Camshaft:

Fig. 7 Rocker Arms & Shafts:

Fig. 8 Rocker Arm Shaft Removal:

Fig. 9 Rocker Arm & Valve Adjusting Screw Inspection:

Fig. 10 Measuring Rocker Arm Shaft Runout:

Fig. 11 Measuring Rocker Arm Shaft Diameter:

Fig. 12 Rocker Arm Shaft Installation:

1. Disconnect battery ground cable.
2. Drain cooling system.
3. Remove flexible A/C compressor suction hose from pipe if equipped.
4. Remove cooling fan and shroud.
5. Remove water pump drive belt and pump pulley.
6. Remove timing belt outside cover, timing belt and tensioner.
7. Remove air intake case and cylinder head cover.
8. Remove camshaft timing belt pulley and timing belt inside cover by inserting a .35 inch rod into hole in camshaft to lock camshaft, Fig. 6.
9. Loosen all valve lash adjusting screw lock nuts and remove all adjusting screws, Fig. 7.
10. Remove rocker arm shaft screws.
11. Remove intake and exhaust rocker arm shafts, rocker arms and springs, Fig. 8.
12. Inspect rocker arm as follows:
a. Replace adjusting screw if tip is badly worn, Fig. 9.
b. Replace rocker arm if cam riding surface is badly worn.
13. Measure rocker arm shaft runout as follows:
a. Ensure rocker arm shaft runout is less than .0004 inch, Fig. 10.
b. Measure rocker arm shaft outer diameter and rocker arm inner diameter using a micrometer and a bore gage, Fig. 11.
c. Rocker arm shaft outer diameter is .628-.629 inch.
d. Rocker arm inner diameter is .629-.630 inch.
e. Rocker arm to shaft clearance is .0005-.00017 inch.
14. Reverse procedure to install noting the following:
a. Apply a thin coat of engine oil to the rocker arms and shafts.
b. When installing the rocker arm shafts, ensure the correct shaft is used for both intake and exhaust rocker arms, Fig. 12.
c. Install intake rocker arm shaft with the stepped side toward the camshaft pulley while the exhaust rocker arm shaft is toward the distributor gear case.
d. Adjust valve lash and belt tension by referring to ADJUSTMENT PROCEDURE/VALVES and SPECIFICATIONS/BELT TENSION DATA.
e. On models with A/C, evacuate and charge A/C system.