Camshaft: Service and Repair

REMOVAL
1. Recover the refrigerant. See Heating and Air Conditioning.
2. Remove the radiator with the A/C condenser. See Cooling System.
3. Remove the valve lifters.
4. Remove the engine front cover.
5. Remove the camshaft sprocket.

CAUTION: All camshaft journals are the same diameter so care must be used in removing the camshaft to avoid damage to the bearings.





6. Remove the camshaft thrust plate bolts.
7. Remove the camshaft thrust plate.

CAUTION: Do not attempt to repair the camshaft, replace it if it is damaged. If a new camshaft is installed, all valve lifters must be replaced. Replace the camshaft bearings, if necessary.

8. Use the following procedure to remove the camshaft:
a. Install three 5/16-18 x 4 in bolts in the camshaft bolt holes.
b. Carefully rotate and pull the camshaft out of the bearings.
9. Inspect the sprocket.
10. Inspect the keyway and threads.
11. Inspect the bearing surfaces lobes for the following conditions:
^ Wear
^ Galling
^ Gouge
^ Overheating (discoloration)
12. Measure the bearing journals. Use a micrometer in order to measure the diameter and run-out. If the journals are out of specification replace the camshaft.

INSTALLATION
1. Coat the camshaft with prelude GM P/N 12345501 or equivalent before installation.
2. Install the camshaft.
3. Install the camshaft thrust plate.
4. Install the camshaft thrust plate bolts. Tighten the thrust plate bolts to 15 Nm (11 ft. lbs.).
5. Install the camshaft sprocket.
6. Install the engine front cover.
7. Install the valve lifters. Refer to Valve Lifter Replacement.
8. Install the radiator with the A/C condenser. See Cooling System.
9. Charge the A/C system. See Heating and Air Conditioning.