SLIPS IN LOW/REVERSE NO REVERSE-REPLACE LOW CLUTCH

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/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.