GM Service Manual Online
For 1990-2009 cars only

Clunk Noise Felt Through Floor Pan - keywords bar bump frame front mount torsion turn suspension

Subject:Clunk Noise Felt Through Floor Pan

Models:1998-2004 Chevrolet Blazer, S-10 4WD
1998-2001 GMC Envoy 4WD
1998-2004 GMC Sonoma 4WD
1998-2004 GMC Jimmy (Canada Only) 4WD
1998-2001 GMC Jimmy (US Only) 4WD
1998-2001 Oldsmobile Bravada AWD



The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

Clunk noise that can be felt through the floor pan on right or left turns, or on uneven road surfaces.

Recommendation/Instructions:

Inspect for witness marks from the torsion bar crossmember contacting the frame rails.

If the torsion bar crossmember is contacting the frame rails, loosen the bolt through the frame to the crossmember hanger. It is important to support the crossmember with the torsion bar loading/unloading tool J 36202. Then install three 1/8" alignment shims and tighten the bolt. Repeat procedure on the other side. It may be necessary to tap in the third shim with a hammer and then tighten the bolt. This procedure will help isolate the crossmember from thumping the frame on flexing maneuvers.

Please follow this diagnostic or repair 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.