For 1990-2009 cars

#### Tools Required

J 7872 Magnetic Base Dial Indicator

1. Clean the camshaft with cleaning solvent.

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

2. Inspect the camshaft for the following conditions:

• | Scored camshaft bearing journals (1)

• | Damaged camshaft lobes (2)

• | Damaged camshaft sprocket locator pins (3)

• | Damaged threads (4)

• | Damage to the camshaft reluctor tooth (5)

3. Measure the camshaft journals using a micrometer.

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

4. Measure the camshaft runout using the J 7872 .

4.1. | Mount the camshaft in V-blocks between the centers.

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

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

5.1. | Lubricate the camshaft using GM P/N United States 12345501, GM P/N Canada 992704 or the equivalent.

5.2. | Set the camshaft on V-blocks.

5.3. | Use the J 7872 in order to measure the lobe lift.

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