CHUGGLE - (NEW CALIBRATION PROMS). Buick Roadmaster 1992

********************************************************************** CONDITION: SOME OWNERS WITH VEHICLES LISTED BELOW, EQUIPPED WITH 5.7L V8 ENGINES (L05, VIN 7), MAY COMMENT ABOUT A "CHUGGLE" CONDITION.

THIS BULLETIN ADDRESSES THE FOLLOWING VEHICLE/CONDITION PROBLEMS ONLY:

VEHICLE - BODY YEAR(S) CONDITION -------------- ------- --------- BUICK - SEDAN + WAGON 1992-93 CHUGGLE WITH BASE AXLE ONLY SEDAN WITH RPO GM8, 2.56 RATIO WAGON WITH RPO GU2, 2.73 RATIO

CHEVROLET - WAGON 1992-93 CHUGGLE WITH BASE AXLE ONLY RPO GU2, 2.73 RATIO

OLDSMOBILE - WAGON 1992 CHUGGLE WITH BASE AXLE ONLY RPO GU2, 2.73 RATIO

CAUSE:

INSUFFICIENT DAMPENING OF THE TORQUE CONVERTER AND PROM CALIBRATION.

CORRECTION:

NEW CALIBRATION PROMS HAVE BEEN RELEASED TO ADDRESS THE ABOVE VEHICLE/CONDITION PROBLEMS.

THE FOLLOWING PROMS ARE NOT RECOMMENDED FOR VEHICLES WITH OPTIONAL AXLE RATIOS OR TRAILER TOWING PACKAGES.

VEHICLES PRODUCED FROM MID-JUNE 1993 THROUGH THE END OF THE MODEL YEAR ARE EXPECTED TO HAVE THIS PROM CHANGE. CHECK PROM SCAN ID.

EMISSION SERVICE SCAN BROADCAST SYSTEM YEARS AXLE RATIO/BODY PROM P/N ID CODE -------- ----- --------------- -------- ---- --------- FEDERAL 92-93 2.56 (GM6)/SEDAN 16195067 5131 BHHP (NA5) 2.73 (GU2)/WAGON 16195067 5131 BHHP

CALIFORNIA 93 2.56 (GM8)/SEDAN 16195072 5141 BHHR (NB2) 2.73 (GU2)/WAGON 16195072 5141 BHHR

PLEASE NOTE: THE ABOVE VEHICLES PRODUCED BEFORE DECEMBER 16, 1991 (JULIAN DATE 350) MAY HAVE HYDRA-MATIC 4L60 MODEL 2DDM TRANSMISSIONS. MODEL 2DDM TRANSMISSIONS MAY CONTAIN TORQUE CONVERTERS WITH INSUFFICIENT DAMPENING.

VEHICLES WITH MODEL 2DDM TRANSMISSION - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH P/N 8650935 (TAGGED B/C: DGAF). IT IS NOT NECESSARY TO REPLACE THOSE TORQUE CONVERTERS WITH P/N 8650935.

TRANSMISSIONS WITH TORQUE CONVERTERS WITH P/N 8656959 (TAGGED B/C: DG5F) NEED TO HAVE THE TORQUE CONVERTER REPLACED WITH P/N 8650935.

MODEL 2BRM TRANSMISSIONS (PRODUCED AFTER DECEMBER 16, 1991) HAVE THE NEW TORQUE CONVERTER.

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

LABOR OPERATION CODE TIME --------------- ---- ---- REPLACE PROM T0500 0.6 HOUR REPLACE TORQUE CONVERTER K7020 2.8 HOURS

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS ONLY. BULLETINS ARE WRITTEN TO INFORM THOSE TECH- NICIANS OF A CONDITION POSSIBLY OCCURRING ON A VEHICLE, OR TO PROVIDE INFORMATION ASSISTING IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS, AND TRAINING TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THE BULLETIN APPLIES TO ALL VEHICLES. SEE AN AUTHORIZED GM DEALER FOR INFORMATION ON WHETHER A SPECIFIC VEHICLE MAY BENEFIT FROM THE INFORMATION.