SLIPS IN LOW/REVERSE NO REVERSE-REPLACE LOW CLUTCH

SUBJECT: * Slips in Manual Low/Reverse, * No Reverse, Repair Low/Reverse Clutch

TRANSMISSION APPLICATIONS: 1986-92 HYDRA-MATIC 3T40 TRANSAXLE (RPO MD9)

TRANSAXLE MODELS: All

VEHICLE APPLICATIONS: 1986 - 1992 Vehicles Chevrolet A, J, L, W Cars/ U Van Pontiac A, J, N, P, T, W Cars/ U Van Oldsmobile A, J, N, W Cars/ U Van Buick A, J, N, W Cars

CONDITION:

---------- Some A, J, L, N, P, T, W Cars and U Vans 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/0-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.

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)

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.

For vehicles repaired under warranty use:

Labor Operation: K-7580

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.