Tools Required

J 7872 Magnetic Base Dial Indicator

1. Remove and discard the camshaft position actuator filter (1).
2. Clean the camshaft with cleaning solvent.




Caution: Bodily injury may occur if the cleaning solvent is inhaled or exposed to the skin.

3. Inspect the camshaft for the following conditions:

•	Scored camshaft bearing journals (5)

•	Damaged camshaft lobes (4)

•	Damaged camshaft position sensor reluctor area (3)

•	Damaged threads (2)




4. Measure the camshaft journals using a micrometer.

If the camshaft journals are not within specifications, replace the camshaft.




5. Measure the camshaft runout using the J 7872 .

5.1.	Mount the camshaft in V-blocks between the centers.

5.2.	Use the J 7872 in order to measure the intermediate camshaft journal.

6. Measure the camshaft lobe lift using the J 7872 .

6.1.	Lubricate the camshaft using GM P/N 12345501 (Canadian P/N 992704) or the equivalent.

6.2.	Set the camshaft on V-blocks.

6.3.	Use the J 7872 in order to measure the lobe lift.

7. If the runout or lobe lift is not within specifications, replace the camshaft.




Important: Always install a NEW camshaft position actuator filter anytime the camshaft position actuator is removed or installed.

8. Install a NEW camshaft position actuator filter (1).