SLIPS IN LOW/REVERSE NO REVERSE-REPLACE LOW CLUTCH

Subject: SLIPS IN LOW/REVERSE-NO REVERSE

Model and Year: 1986-90 CELEBRITY, 1986-92 CAVALIER, 1987-92 CORSICA AND BERETTA, 1990-92 LUMINA, 1990-92 LUMINA APV - ALL WITH 3T40 AUTOMATIC TRANSMISSION

TRANSAXLE APPLICATIONS: SUBJECT:

1986-92 HYDRA-MATIC 3T40 *Slips in Manual Low/Reverse TRANSAXLE (RPO MD9) * No Reverse Repair Low/Reverse Clutch

TRANSAXLE MODELS: VEHICLE APPLICATIONS:

All A, J, L, W Cars and U Van

CONDITION:

--------- Some A, J, L, 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

* TN 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 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.

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.