SECOND GEAR VIBRATION AT 3000- 5000 RPM (INST. SHAFT PACKAGE)

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SUBJECT: SECOND GEAR VIBRATION AT 3000-5000 RPM (INSTALL SHAFT PACKAGE)

MODELS: 1991-93 CADILLAC DEVILLE 1991-93 CADILLAC FLEETWOOD 1991-93 BUICK PARK AVENUE 1991-93 OLDSMOBILE NINETY EIGHT 1991-92 OLDSMOBILE TORONADO 1991-93 CADILLAC ELDORADO 1991-93 BUICK RIVIERA 1991-93 PONTIAC BONNEVILLE 1991-93 OLDSMOBILE EIGHTY EIGHT 1991-93 BUICK LE SABRE 1991-93 CADILLAC SEVILLE 1991-93 OLDSMOBILE CUTLASS SUPREME 1991-93 PONTIAC GRAND PRIX 1991-93 CHEVROLET LUMINA 1991-93 BUICK REGAL 1992-93 CHEVROLET LUMINA APV 1992-93 OLDSMOBILE SILHOUETTE 1992-93 PONTIAC TRANS SPORT

TRANSAXLE APPLICATIONS:

1993 HYDRA-MATIC 4T60-E (RP0 M13)

CONDITION: (FIGURE 1) SOME VEHICLES MAY EXHIBIT A TRANSAXLE VIBRATION AT AN ENGINE SPEED BETWEEN 3000-5000 RPM WHEN IN SECOND GEAR (ONLY).

NOTE: SECOND GEAR VIBRATION SOUNDS VERY SIMILAR TO GROUNDED OUT ENGINE MOUNTS.

CAUSE:

WHEN ENGINE SPEED IS BETWEEN 3000-5000 RPM, A DISTURBANCE MAY OCCUR BETWEEN THE OUTPUT SHAFT ASSEMBLY NEAR THE BEARING, INPUT SUN GEAR (511) AND COMPONENTS ATTACHED TO THE SUN GEAR SHAFT (668). THIS DISTURBANCE MAY BE ENOUGH TO CAUSE A VIBRATION WHILE IN SECOND GEAR.

CORRECTION: (FIGURE 2) THE INPUT SUN GEAR BEARING (511) AND INPUT SUN GEAR BEARING JOURNAL HAVE BEEN REMOVED FROM THE OUTPUT SHAFT (510), AND REPLACED WITH A (NEW) 4TH CLUTCH SHAFT TO INPUT HOUSING BEARING (723). THE 4TH CLUTCH SHAFT TO INPUT HOUSING BEARING IS LOCATED ON THE (INNER DIAMETER) INPUT SHAFT OF THE INPUT AND 3RD ASSEMBLY. TO ACCOMMODATE THIS NEW 4TH CLUTCH SHAFT TO INPUT HOUSING BEARING (723), A BUSHING HAS BEEN ADDED TO THE BASE (OUTER DIAMETER) OF THE SHAFT ASSEMBLY 4TH CLUTCH, (504).

NOTE: INPUT SUN GEAR (668) WAS ALSO MODIFIED. THE SURFACE FINISH SPECIFICATION HAS BEEN REDUCED FROM THE INNER DIAMETER (INPUT SUN GEAR BEARING SURFACE) MAKING IT UNABLE TO BE USED IN A TRANSAXLE WITH A INPUT SUN GEAR BEARING (511). THE PRIOR INPUT SUN GEAR (PART NUMBER 8682441) CAN BE USED IN EITHER APPLICATION.

THE REMOVAL AND/OR RELOCATION OF THE ABOVE BEARINGS ISOLATED THE OFFENDING COMPONENTS AND DAMPENED THE VIBRATION WHILE IN 2ND GEAR.

DATE OF PRODUCTION: EFFECTIVE JUNE 1, 1993 (JULIAN DATE 152) ALL 1993 HYDRA-MATIC 4T60-E TRANSAXLES WILL BE BUILT WITH THE NEW 4TH CLUTCH SHAFT TO INPUT HOUSING BEARING AND NEW HUB AND SHAFT ASSEMBLY 4TH CLUTCH. HYDRA-MATIC 4T60 TRANSAXLES WILL BE UNEFFECTED. NO HYDRA-MATIC 4T60 PRODUCTION OR SRTA TRANSAXLES WILL BE BUILT WITH THE NEW 4TH CLUTCH SHAFT TO INPUT HOUSING BEARING AND NEW SHAFT ASSEMBLY 4TH CLUTCH.

SRTA INFORMATION:

THE 4T60-E SERVICE REPLACEMENT TRANSMISSION ASSEMBLY (SRTA) WILL PHASE THE 4TH CLUTCH SHAFT TO INPUT HOUSING BEARING AND HUB AND SHAFT ASSEMBLY 4TH CLUTCH INTO PRODUCTION WHEN SUFFICIENT PARTS ARE AVAILABLE. SRTA TRANSAXLES ARE SCHEDULED TO BE AVAILABLE AFTER NOVEMBER 15, 1993.

SERVICE PART INFORMATION:

PART NUMBER PART NUMBER (PREVIOUS) (NEW) DESCRIPTION MODEL

NONE 8651936 SHAFT PACKAGE-VIBRATION REPAIR ALL

SHAFT PACKAGE-VIBRATION REPAIR CONTAINS THE FOLLOWING: 8676613 24201094 SHAFT ASSEMBLY-4TH CLUTCH ALL

8651924 8651937 SHAFT KIT, INPUT (WITH HOUSING) ALL

8651716 8683560 SHAFT-OUTPUT ALL

8675032 NOT USED BEARING-INPUT SUN GEAR ALL TO OUTPUT SHAFT

8682441 8683559 GEAR-INPUT SUN ALL

PARTS ARE EXPECTED TO BE AVAILABLE ON NOVEMBER 15, 1993.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY USE: LABOR OPERATION NUMBER: K7537

FIGURES: 2

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER." THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS OCCURRING 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 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.

COPYRIGHT 1993. GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.