Camshafts Cleaning and Inspection

WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

Tools Required : J 7872 Magnetic Base Dial Indicator Set

Clean the camshafts with cleaning solvent.
Inspect the camshafts for the following conditions:
- Scored camshaft journals
- Damaged camshaft lobes
- Damaged camshaft sprocket locator pins
- Damaged threads
Measure the camshaft lobes using a micrometer. The intake camshaft lobes should be a minimum of 41.5 mm (1.635 in). The exhaust camshaft lobes should be a minimum of 41 mm (1.615 in).

Fig 1: Measuring Camshaft Lobes

Courtesy of GENERAL MOTORS CORP.

Use J 7872 to measure the camshaft runout.
1. 4.1. Set the camshaft in V-blocks between the centers.
2. 4.2. Measure the intermediate camshaft journal.

Fig 2: Measuring Camshaft Runout And Camshaft Lobe Lift

Courtesy of GENERAL MOTORS CORP.

Use J 7872 to measure the camshaft lobe lift.
1. 5.1. Lubricate the camshaft to V-block contact areas with engine oil.
2. 5.2. Set the camshaft on V-blocks.
3. 5.3. Measure the camshaft lobe lift.
If the runout or camshaft lobe lift is not within specifications, replace the camshaft.