REMOVAL & INSTALLATION
- Remove the engine from the vehicle and place on a suitable stand as outlined in the Engine removal procedures in this section.
- Remove the intake manifold as outlined in the Intake Manifold removal section.
- Remove the rocker arm covers and loosen the rocker arm bolts enough to move them aside to remove the pushrods.
Mark all valve components to ensure installation will be in same location as removal.
- Remove the valve lifters. Mark each lifter to ensure installation will be in same location as removal.
- Remove the timing chain front cover as outlined in the Timing Chain Cover removal procedures.
- Remove the timing chain and sprocket.
- Remove the rear cover. Refer to the Camshaft Rear Cover illustration in this section.
- Carefully remove the camshaft to avoid damage to the bearings.
Install a 6 inch long M8X1.25 size bolt into the camshaft sprocket bolt hole to remove the camshaft.
- Before installation, lubricate the camshaft journals and lobes with Assembly Lube®.
If a new camshaft is to be installed, coat the lobes with Assembly Lube such as GM E.O.S. or its equivalent.
- Install the camshaft using a six inch long M8X1.25 size bolt in the camshaft sprocket bolt hole. Be careful not to damage the camshaft bearings during installation.
- Install the camshaft sprocket and timing chain as outlined in the Timing Chain installation procedures in this section.
The timing marks have to be lined up at this time.
- Apply RTV sealer to the rear camshaft cover and install the cover with the three attaching bolts. Torque the bolts to 6-9 ft. lbs. (8-12 Nm).
- Install the timing chain front cover as outlined in the Timing Chain Cover installation procedures.
- Apply Assembly Lube® to the valve lifters and install into their previously marked lifter bores.
- Install the pushrods into their previously marked positions. Adjust the valve lash as follows:
Rotate the engine until the mark on the torsional damper lines up with the "0" mark on the timing tab, with the engine in the No. 1 firing position. This may be determined by placing fingers on the No. 1 rocker arms as the mark on the damper comes near the "0" mark. If the valves are not moving, the engine is in the No. 1 firing position, . With the engine in the No. 1 firing position, the following valves may be adjusted:
Exhaust-1, 2, 3
- Back out the adjusting nut until lash is felt at the pushrod, then turn the adjusting nut until all lash is removed. This can be determined by rotating the pushrod while turning the adjusting nut. When lash has been removed, turn the adjusting nut in 1 1 / 2 additional turns to center the lifter plunger.
Crank the engine one revolution until the timing tab "0" mark and torsional damper mark are again in alignment. This is the No. 4 firing position. With the engine in this position, the following valves may be adjusted. Refer to the Timing Chain illustrations for timing marks:
Exhaust-4, 5, 6
- Install the engine assembly into the vehicle as outlined in the Engine installation procedures in this section.