Rocker Arm Assembly: Service and Repair
REMOVAL1. Disconnect battery ground cable, then remove cylinder head cover.
2. Remove distributor from cylinder head.
3. Loosen all valve adjusting screw locknuts, then turn adjusting screws back completely.
4. Remove rocker arm shaft screws, then pull out both rocker arm shafts.
5. Remove rocker arms and springs.
6. Remove timing belt as outlined under TIMING BELT & TENSIONER.
7. Insert rod into hole of camshaft, then remove camshaft pulley bolt.
8. Remove distributor case and camshaft from cylinder head.
INSPECTION
Rocker Arm & Shaft
1. Using a suitable micrometer and a bore gauge, measure rocker shaft diameter and rocker arm inside diameter. Note readings.
2. Rocker shaft diameter should be 0.628-0.629 inch. If diameter is not as specified, replace shaft.
3. Rocker arm inside diameter should be 0.629-0.630 inch. If diameter is not as specified, replace arm.
4. Take readings obtained in steps 2 and 3, and the difference between the two readings is arm to shaft clearance. Arm to shaft clearance should be 0.0005-0.0017 inch. If clearance is not as specified, replace shaft or arm as necessary.
5. Using ``V'' blocks and a suitable dial indicator, check runout of rocker arm shaft. Runout should not exceed 0.004 inch.
Camshaft Lobe Height & Runout
1. Using a micrometer, measure cam lobe height. If measured height is below 1.4975 inches for intake or exhaust cam, replace camshaft.
2. Using dial gauge, measure camshaft runout. If measured runout exceeds .0039 inch, replace camshaft.
Camshaft Journal Wear
Fig. 27 Camshaft Journal Measurement:
Fig. 28 Camshaft Journal & Journal Bore Specifications:
1. Measure journal diameter at four places to on each journal, Fig. 27. Journal diameter should be as specified in Fig. 28.
2. Using bore gauge, measure journal bores in cylinder head. Journal bore diameter should be as specified in Fig. 28.
3. Subtract journal diameter measurement from journal bore measurement to determine journal clearance. Journal clearance should not exceed .0059 inch.
4. If journal clearance exceeds specifications, replace camshaft and/or cylinder head.
INSTALLATION
Fig. 29 Rocker Arm Shaft Installation:
Reverse removal procedure to install, noting the following:
1. Install camshaft to cylinder head from transmission case side.
2. Install rocker arm shafts as specified, Fig. 29.
3. Adjust valve lash as outlined under ADJUSTMENT PROCEDURES/VALVES.