REAR SUSP. AUX. SPRING NOISE, ATTACHING BRKT. REPOSITIONING

Subject: REAR SUSPENSION AUXILIARY SPRING THUD/CLUNK

Model and Year: 1990-91 LUMINA

Condition: Some 1990-91 W-cars equipped with auxiliary rear springs may exhibit a thud/clunk type noise coming from the rear of the vehicle that is audible in the passenger compartment. This condition is most apparent after a harsh/sharp road input such as a chuck-hole/speed bump.

Cause: Auxiliary rear spring lower attaching bracket not in full contact with rear spindle rod. Under certain operating conditions lower attaching bracket may flex and contact spindle rod resulting in thud/clunk noise.

Correction: Following service procedure indicated below, insure that the auxiliary rear spring lower brackets are properly seated on spindle rods.

Service Procedure:

1. Raise vehicle and support in such a manner that rear suspension is extended in a full downward position.

2. Inspect both right and left hand auxiliary spring lower brackets to insure they are in contact with spindle rods utilizing a .002" feeler gage.

3. If a bracket is not in contact, loosen lower bracket to spindle rod bolt a maximum of two revolutions. Let bracket position itself on spindle rod and re-torque bolt(s) to 46 N.m (36 lbs. ft.).

CAUTION:

THE AUXILIARY SPRINGS ARE UNDER COMPRESSION AND BOLTS MUST NOT BE REMOVED. DOING SO MAY RESULT IN PERSONAL INJURY.

4. Lower vehicle.

Labor Operation Number: T1752 Labor Time: 0.3 Hours

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.