TSB 92-7-18: A/T - No Reverse or Slips In Low/Reverse

Details

9228pontiac01 Bulletin Number: 92-7-18 Reference Number: 277123 Publish Date: 6/92 Subject: SLIPS IN LOW/REVERSE - NO REVERSE (DIAGNOSE/REPLACE LOW/REVERSE CLUTCH) Models Affected: 1986-92 6000, SUNBIRD, GRAND AM, FIERO, LEMANS, GRAND PRIX AND TRANS SPORT MODELS WITH 3T40 TRANSAXLE APPLICATIONS: 1986-92 HYDRA-MATIC 3T40 TRANSAXLE (RPO MD9) TRANSAXLE MODELS: All CONDITION: Some 6000, Sunbird, Grand Am, Fiero, LeMans Grand Prix and Trans Sport models equipped with HYDRA-MATIC 3T40 transaxles and manufactured the model years 1986 through 1992 may exhibit symptoms associated with wear in the low/reverse clutch pack. These symptoms are: * Transaxle slips in manual low or reverse gears * Transaxle inoperative in reverse gear CAUSE: (See Figure 1) If this condition exists (and upon inspection of the low /reverse components), and it is noted that the piston outer lip seal is cut due to piston overtravel, this overtravel could possibly cause flattening of the low/reverse release spring (655) and deflection of the low/ reverse clutch spring retainer (656). CORRECTION: Proper diagnostics for either of the above symptoms should be performed prior to attempted repair for any condition. Diagnosis should include: * Check fluid levels * T/V cable adjustment * Fluid pressure check * Manual valve secured * Low/reverse pipe not bent; washer seal/O-ring secured; pipe brackets tight * Low/reverse piston seals uncut and properly installed * No loose retainers * Cup plug seal properly installed (not cut) * Backing plate in proper location * Driven sprocket support Teflon seals * Direct clutch seals If the diagnostic conditions are met and further repair is required, both the below listed service parts should be replaced with the low/reverse clutch components using Labor Code K7580. Include the replacement of the low/reverse release spring (655), clutch spring retainer (656), and piston snap ring (657) as part of total repair (see Figure 1). SERVICE PARTS INFORMATION: Service Part Name/Service Package Package Number Low/Reverse Clutch Release Spring (655) 8628222 Low/Reverse Clutch Retainer and Snap Ring 8664961 (656/657) These service packages are currently available from GMSPO. Use applicable Labor Time Guide for labor hours. SERVICE MANUAL REFERENCE: Refer to the "Automatic Transaxle Diagnosis/Unit Repair" section of your service manual for necessary low/reverse clutch diagnostic and repair information.