REAR STRUT THUMPING NOISE (REPLACE STRUT JOUNCE BUMPER). Buick Regal 1992

REVISION: 01/03/95

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 ----------------------------------------------------------------------

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

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 TOPMOUNT/ROD NUTS TO 75-110 N.M (56-81 LBS. FT.) HOLDING ROD WITH #50 TORX.

6. INSTALL STRUT ASSEMBLIES IN VEHICLE FOLLOWING APPLICABLE PROCEDURES IN SERVICE MANUAL, SECTION 3D.

PART AVAILABILITY:

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE: LABOR OPERATION NUMBER: T1836 LABOR TIME: 1.4 HRS. (SINGLE EXHAUST) 1.8 HRS. (DUAL EXHAUST) ADD 0.3 HR. FOR AUXILIARY SPRINGS

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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.