GM Service Manual Online
For 1990-2009 cars only

Checks

Cause

Additionally, noise is most noticeable under light throttle

Drive Link Assembly System

Verify a noise from the sprockets or the drive link assembly (chain) by placing your left foot on the brake and by moving the gear selector from Park or Neutral to Drive or Reverse. If the noise stops, check the remaining items in this list.

Drive Link (Chain) Assembly (101)

Stretched

Drive Sprocket and Driven Sprocket (103, 102)

Broken or sheared teeth

Drive and Driven Sprocket Support Bearing Assemblies (108, 121)

Bearing race or roller bearing surfaces are rough or pitted

Drive Sprocket Support and Driven Sprocket Support (109, 602)

Bearing outer race support is rough or nicked