01-03 Pontiac Aztec and Buick Rendezvous AWD B Van Loose Lumber / Clunk Noise from Rear Suspension - kw accelerate arm bump bushing control loose rattle stop wear

The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.

Customers may complain of a loose lumber/clunk noise from the rear underside of the vehicle (AWD models). The noise can be heard under acceleration from a stop or when coming to a complete stop. It may also be heard while going over bumps.

After checking for proper operation of other suspension components that may make this type of noise (i.e. shock absorbers), advise the tech to inspect the rear knuckle assembly, specifically, the bushing at the top of the assembly where the upper control arm attaches to the knuckle. To test for this condition:

1. Apply the park brake (vehicle not running).
2. Place finger on the bushing.
3. Rock vehicle back and forth.

The clunk should be able to be felt at this point. The correction is to replace the rear knuckle assembly (bushing not serviced separately). The part in question can be viewed in SI under SUSPENSION => REAR SUSPENSION => KNUCKLE REPLACEMENT AWD.

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.

(2001-2003 PONTIAC AZTEK AWD) and (2002-2003 BUICK RENDEZVOUS AWD)

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