NO REVERSE-NEW REAR BAND ASSY. TRUCKS WITH 4L80E/4L80EHD

SUBJECT: NO REVERSE (NEW REAR BAND ASSEMBLY)

MODELS: 1991-92 C/K, R/V, G, P TRUCKS WITH 4L80E/4L80EHD

CONDITION:

Some HYDRA-MATIC 4L80-E/4L80-EHD Transmissions may experience a no reverse condition.

CAUSE:

----- This is caused by the lugs on the rear band assembly not holding to the case pins, causing the reaction drum not to hold.

CORRECTION:

---------- A new Rear Band Assembly was released to eliminate anchor lug fatigue.

DATE OF PRODUCTION: (Figures 1 & 2) ----------------------------------- Starting April 11, 1992 (Julian Date 101) all 4L80-E/4L80-EHD were built with this new Rear Band Assembly.

SERVICE PART INFORMATION:

8681620 Band Assembly, Rear Brake

Parts are currently available at GMSPO.

SERVICE PROCEDURE: (Figure 3) ----------------------------- On all 1991 vehicles, the Band Assembly and Case Assembly with added ribs to strengthen the anchor pin area must be serviced together. All 1992 vehicles have the new Case Assembly, only the Band Assembly is serviced. Refer to your appropriate catalog for correct case assembly numbers.

The previous Band Assembly (8677313) can be used, until new bands are available, if the band has a blue ink stamp 295 or has an identification date stamp.

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.