INTERMITTENT NEUTRAL OR LOSS OF DRIVE AT HIGHWAY SPEEDS. Buick Regal 1995

SUBJECT: INTERMITTENT NEUTRAL OR LOSS OF DRIVE AT HIGHWAY SPEEDS OR FROM FOURTH GEAR (REPLACE CONTROL VALVE BODY ASSEMBLY)

MODELS: 1995-96 BUICK SKYLARK, REGAL, CENTURY, PARK AVENUE, RIVIERA, LESABRE 1997 BUICK SKYLARK, REGAL, CENTURY, LESABRE 1995-96 CHEVROLET BERETTA, CORSICA, LUMINA APV, LUMINA, MONTE CARLO 1997 CHEVROLET LUMINA, MONTE CARLO, VENTURE 1995 CADILLAC DEVILLE 1995-96 OLDSMOBILE CUTLASS CIERA, CUTLASS CRUISER, LSS, NINETY EIGHT, NINETY EIGHT REGENCY, EIGHTY EIGHT, ACHIEVA, SILHOUETTE, CUTLASS SUPREME 1997 OLDSMOBILE EIGHTY EIGHT, ACHIEVA, CUTLASS SUPREME, LSS, SILHOUETTE 1995-97 PONTIAC BONNEVILLE, GRAND AM, TRANS SPORT, GRAND PRIX WITH HYDRA-MATIC 4T60-E TRANSAXLE (RPO M13)

CONDITION:

SOME OWNERS MAY COMMENT ABOUT AN INTERMITTENT NEUTRAL CONDITION WHILE DRIVING AT HIGHWAY SPEEDS OR INTERMITTENT NEUTRAL FROM FOURTH GEAR.

CAUSE:

THE 3-2 MANUAL DOWNSHIFT VALVE MAY BE STICKING INTERMITTENTLY. WHEN THE 3-2 DOWNSHIFT VALVE STICKS, THIS ALLOWS THE 2-3 SHIFT VALVE TO FLOAT IN ITS BORE EITHER EXHAUSTING 2ND, 3RD AND 4TH CLUTCH OIL OR SENDING D-4 OIL INTO THE AUX INPUT CLUTCH FEED. EXHAUSTING THE 3RD AND 4TH CLUTCH OIL COULD CAUSE AN INTERMITTENT LOSS OF DRIVE. SENDING D-4 OIL INTO THE INPUT CIRCUIT COULD CAUSE A POTENTIAL TIE UP CONDITION BY ENGAGING THE INPUT CLUTCH AND 4TH CLUTCH.

CORRECTION:

INSPECT THE TRANSMISSION FLUID AND PAN FOR SIGNS OF DISTRESSED CLUTCHES OR ANY ABNORMAL AMOUNTS OF DEBRIS. REMOVE AND DISASSEMBLE THE 1-2 AND 2-3 ACCUMULATOR HOUSING ASSEMBLY. INSPECT THE ACCUMULATOR HOUSING AND COVER FOR ANY SIGNS OF SCORING, SEDIMENT, OR ABNORMALITIES THAT COULD GENERATE DEBRIS. IF ANY OF THE ABOVE CONDITIONS ARE FOUND, MAKE THE NECESSARY REPAIRS TO THOSE ITEMS. THEN INSPECT THE 2-3 (357) AND 3-2 (356) VALVE LINE UP. IF THE VALVES ARE SCORED, REPLACE THE CONTROL VALVE BODY ASSEMBLY.

PARTS INFORMATION REFER TO THE LATEST SERVICE PARTS CATALOG FOR THE PROPER CONTROL VALVE BODY ASSEMBLY PART NUMBERS. ANODIZED VALVES ARE BEING INSTALLED INTO THE 2-3 (357),AND 3-2 (356) VALVE LINE UP, AND THE MACHINING OPERATION FOR THE VALVE BODY HAS BEEN REFINED TO PRODUCE A CLEAN VALVE BORE.

WARRANTY INFORMATION FOR VEHICLES REPAIRED UNDER WARRANTY USE: LABOR OPERATION LABOR TIME K6570 USE PUBLISHED LABOR OPERATION TIME AND APPROPRIATE ADD TIME FOR ACCUMULATOR HOUSING INSPECTION

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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.