Suspension - Rear Strut Related Squeaking/Thumping Noise

File In Section: 3 - Steering/Suspension

Bulletin No.: 13-34-05

Date: January, 1995

Subject:
Rear Strut Related Thumping/Squeaking Noise
(Replace Strut Jounce Bumper Assemblies)

Models:
1989-95 Buick Regal
1990-94 Chevrolet Lumina
1989-95 Oldsmobile Cutlass Supreme
1989-95 Pontiac Grand Prix

This bulletin is being revised to add model years 1993-95.
Previous divisional publication numbers were:

Buick 92-3-7,
Chevrolet 92-82B-3D
GM of Canada 92-3-112
Oldsmobile 92-T-40
Pontiac 92-3-5A

CONDITION
Some owners may comment that the vehicle exhibits a repetitive muted thumping (oil canning) and/or squeak noise coming from the rear of the vehicle. This condition is most apparent inside the passenger compartment when the vehicle is operated at low speeds over irregular road surfaces that generate short repetitive inputs into the suspension system.

CAUSE
A load spike caused by the strut jounce bumper system transmitting noise through the body strut tower structure.

CORRECTION
Replace both rear strut jounce bumper assemblies with new assemblies contained in service unit, P/N 22063945, following service procedure indicated below:

SERVICE PROCEDURE

1. Following applicable procedure in the Service Manual, Section 3D, remove both rear struts from vehicle and identify struts from which side of vehicle they were removed.

2. With struts on bench, remove top mount/rod nuts utilizing # 50 torx to hold strut rod while removing nuts.

3. Remove jounce bumper assemblies and discard along with nuts.

4. Install new jounce bumper assemblies and nuts contained in service unit, P/N 22063945.

5. Torque top mount/rod nuts to 75-110 Nm (56-81 lb.ft.) holding rod with # 50 torx.

6. Install strut assemblies in vehicle following applicable procedures in Service Manual, Section 3D.

PARTS INFORMATION
Parts are currently available from GMSPO.





WARRANTY INFORMATION
For vehicles repaired under warranty, use: