HARSH 1-2, 2-3, AND 3-4 UPSHIFTS (REPAIR ACC. VALVES)

REVISION: 03/01/94

THIS BULLETIN IS BEING REVISED TO INCLUDE U VAN APPLICATIONS.

SUBJECT: HARSH 1-2, 2-3 AND 3-4 UPSHIFTS (REPAIR ACCUMULATOR VALVE(S) IN CONTROL VALVE BODY)

MODELS: 1991 BUICK REATTA 1991-93 BUICK RIVIERA 1991-94 BUICK PARK AVENUE AND REGAL 1992-94 BUICK LE SABRE 1994 BUICK CENTURY AND SKYLARK 1991-93 CADILLAC ELDORADO, SEVILLE, SIXTY SPECIAL AND FLEETWOOD (FWD) 1991-94 CADILLAC DE VILLE 1991-94 CHEVROLET LUMINA 1994 CHEVROLET BERETTA AND CORSICA 1992-94 CHEVROLET LUMINA APV 1991-92 OLDSMOBILE TORONADO AND TROFEO 1991-94 OLDSMOBILE NINETY EIGHT AND CUTLASS SUPREME 1992-94 OLDSMOBILE EIGHTY EIGHT AND SILHOUETTE 1994 OLDSMOBILE CUTLASS CIERA AND ACHIEVA 1992-94 PONTIAC BONNEVILLE AND TRANS SPORT 1991-94 PONTIAC GRAND PRIX 1994 PONTIAC GRAND AM

TRANSAXLE APPLICATIONS: HYDRA-MATIC 4T60-E (RPO M13)

CONDITION:

SOME OWNERS MAY EXPERIENCE A HARSH 1-2, 2-3 OR 3-4 UPSHIFT CONDITION. THE HARSH UPSHIFT CONDITION WILL USUALLY BE NOTICEABLE DURING A LIGHT TO MEDIUM THROTTLE UPSHIFT.

CAUSE: (FIGURES 1, 2 AND 3) THE HARSH UPSHIFT CONDITION MAY BE CAUSED BY:

O A MISSING OR LOOSE ACCUMULATOR BUSHING RETAINER.

O A METAL SHAVING (BURR) OR DEBRIS IN THE ACCUMULATOR VALVE TRAIN IN THE CONTROL VALVE BODY.

IMPORTANT: ALL 4.9L MODELS AND 3.1L MODELS 3BHW AND 4AFW HAVE A 1-2 ACCUMULATOR VALVE TRAIN AND PISTON/SPRING LINE UP THAT IS DIFFERENT FROM ALL OTHER 4T60-E MODELS. DO NOT ASSUME THAT THESE MODELS HAVE A HARSH SHIFT CONDITION DUE TO MISASSEMBLY. FIGURES 2 AND 3 CORRECTLY SHOW THE 1-2 ACCUMULATOR COMPONENTS FOR THESE MODELS. THE 1993 AND 1994 HYDRA-MATIC 4T60-E AUTOMATIC TRANSAXLE UNIT REPAIR SECTION 7A-5B IS INCORRECT.

CORRECTION: (FIGURES 2 AND 3) TO REPAIR THIS CONDITION, INSPECT THE CONTROL VALVE BODY FOR THE FOLLOWING:

O ACCUMULATOR BUSHING RETAINERS FOR BEING PRESENT AND SECURELY INSTALLED. IF A RETAINER IS MISSING, REFER TO SERVICE PART INFORMATION FOR RETAINER PART NUMBERS.

O ACCUMULATOR VALVE TRAIN IN THE CONTROL VALVE BODY FOR BINDING DUE TO BURRS OR DEBRIS. DISASSEMBLE AND CLEAN THE CONTROL VALVE BODY IF BURRS OR DEBRIS ARE FOUND.

SERVICE PART INFORMATION: (FIGURE 4) THE ACCUMULATOR BUSHING RETAINER DESIGN WAS CHANGED AFTER THE START OF THE 1993 MODEL YEAR. PREVIOUS AND CURRENT DESIGN ACCUMULATOR BUSHINGS AND RETAINERS ARE NOT INTERCHANGEABLE. TO DETERMINE THE CORRECT ACCUMULATOR RETAINER BUSHING TO ORDER FOR 1993 MODEL TRANSAXLES, INSPECT ONE OF THE OTHER ACCUMULATOR BUSHING RETAINERS THAT IS PRESENT IN THE CONTROL VALVE BODY. COMPARE WITH FIGURE 2 TO DETERMINE THE CORRECT PART NUMBER TO ORDER.

+-----------------------------------------------------------+ | PART NUMBER | DESCRIPTION | MODELS | |-------------+--------------------------------+------------| | | | ALL 1991 | | 8651493 | RETAINER, ACCUMULATOR BUSHING | ALL 1992 | | | (3/PACKAGE) | EARLY 1993 | |-------------+--------------------------------+------------| | 8681510 | RETAINER, ACCUMULATOR BUSHING | LATE 1993 | | | (3/PACKAGE) | ALL 1994 | +-----------------------------------------------------------+

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION: K6570 LABOR TIME: USE PUBLISHED LABOR OPERATION TIME.

+-----------------------------------------------------+ | LEGEND FOR FIGURES 2, 3 AND 4 | |-----------------------------------------------------| | ITEM | COMPONENT DESCRIPTION | |------+----------------------------------------------| | 3 | CASE, TRANSAXLE | | 103 | BOLT, 2-1 SERVO COVER TO CASE | | 104 | COVER, 2-1 MANUAL SERVO BODY | | 105 | SEAL, SQUARE CUT (2-1 SERVO) | | 106 | CLIP, RETAINING (BOTTOM) | | 107 | SEAL, LIP | | 108 | PISTON, 2-1 MANUAL SERVO | | 109 | SPRING, 2-1 MANUAL SERVO CUSHION | | 110 | RETAINER, INT. SERVO SPRING MANUAL CUSHION | | 111 | PIN, 2-1 MANUAL APPLY | | 112 | SPRING, 2-1 MANUAL SERVO RETURN | | 113 | SEAL, O-RING | | 114 | BODY, 2-1 MANUAL SERVO | | 115 | FILTER, 2-1 SERVO | | 124 | PIPE, FORWARD SERVO APPLY | | 125 | PIPE, MANUAL SERVO APPLY | | 126 | PIPE, LUBE OIL | | 127 | CLAMP, HOSE | | 128 | HOSE, LUBE OIL | | 129 | RETAINER, LUBE PIPE CLIP | | 130 | PIPE AND WASHER ASSEMBLY | | 131 | BOLT, ACC. COVER TO CASE AND ACC. HOUSING | | 132 | COVER, ACCUMULATOR | | 133 | GASKET, ACCUMULATOR COVER | | 134 | PLATE, ACCUMULATOR SPACER | | 135 | PIN, 2-3 ACCUMULATOR | | 136 | PISTON, 1-2 AND 2-3 ACCUMULATOR | | 137 | RING, OIL SEAL ACCUMULATOR PISTON | | 138A | SPRING, 2-3 ACCUMULATOR (INNER) | | 138B | SPRING, 2-3 ACCUMULATOR (OUTER) | | 139B | SPRING, 1-2 ACCUMULATOR (INNER) | | 139C | SPRING, 1-2 ACCUMULATOR (OUTER) | | 140 | HOUSING, ACCUMULATOR | | 301 | BODY, CONTROL VALVE | | 338 | RETAINER, 1-2 ACCUMULATOR PLUG | | 339 | PLUG, 1-2 ACCUMULATOR | | 340 | SPRING, 1-2 ACCUMULATOR VALVE (PRIMARY) | | 341 | VALVE, 1-2 ACCUMULATOR (PRIMARY) | | 342 | BUSHING, 1-2 ACCUMULATOR VALVE (PRIMARY) | | 343 | VALVE, 2-3 ACCUMULATOR | | 344 | SPRING, 2-3 ACCUMULATOR VALVE | | 345 | BUSHING, 2-3 ACCUMULATOR VALVE | | 346 | PLUG, 1-2 ACCUMULATOR (SECONDARY) | | 347 | VALVE, 1-2 ACCUMULATOR (SECONDARY) | | 348 | SPRING, 1-2 ACCUMULATOR VALVE (SECONDARY) | | 349 | BUSHING, 1-2 ACCUMULATOR VALVE (SECONDARY) | | 350 | VALVE, 3-4 ACCUMULATOR | | 351 | SPRING, 3-4 ACCUMULATOR VALVE | | 352 | BUSHING, 3-4 ACCUMULATOR VALVE | | 385 | RETAINER, ACCUMULATOR VALVE BUSHING ASSEMBLY | +-----------------------------------------------------+

FIGURES: 4

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.

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