NEW SILICONE BEADED SIDE COVER & BOTTOM PAN GASKET

SUBJECT NEW SILICONE BEADED SIDE COVER AND BOTTOM PAN GASKET (NEW PRODUCT INFORMATION)

MODELS/YEARS ALL 1980-91 MODELS EQUIPPED WITH A HYDRA-MATIC 3T40 (RPO-MD9) TRANSAXLE

This bulletin covers a new side cover and bottom pan gasket for all HYDRA-MATIC 3T40 transaxles, which reduces the potential for side cover and/or bottom pan leaks. These new gaskets are light gray in color and can be identified by a silicone bead which is dark orange in color (see illustration).

DATE OF PRODUCTION CHANGE:

These new gaskets went into production July 16, 1990 (Julian Date 197) for all Windsor and Willow Run built HYDRA-MATIC 3T40 transaxles.

SERVICE PROCEDURE:

These new gaskets can be used on all previous model HYDRA-MATIC 3T40 transaxles. Whenever installation or replacement of this new gasket is necessary, refer to the following procedure.

SIDE COVER GASKET:

1. Clean ribbed surface of side cover and machined surface of case where gasket is to be installed. Both surfaces MUST be free of transmission fluid.

2. Place side cover gasket on case with silicone bead facing out.

3. Carefully install side cover onto gasket and install all pan bolts (7) by hand.

IMPORTANT: The rib on the pan must fully contact the entire silicone bead. --------- If it does not, leakage may occur.

4. Torque all pan bolts to 11 N-m (98 Lb. In.).

BOTTOM PAN GASKET:

1. Clean ribbed surface of bottom pan and machined surface of case where gasket is to be installed. Both surfaces MUST be free of transmission fluid.

2. Place bottom pan gasket on case with silicone bead facing out.

3. Carefully install bottom pan onto gasket and install all pan bolts by hand.

IMPORTANT: The rib on the pan must fully contact the entire silicone bead. If it does not, leakage may occur.

4. Torque all pan bolts to 11 N-m (98 Lb. In.).

SERVICE PARTS INFORMATION:

Whenever ordering this new silicone beaded gasket, refer to the following part numbers:

Part Number Description ----------- ------------ 8678169 Side cover gasket 8678168 Bottom pan gasket

All HYDRA-MATIC 3T40 service packages that contain side cover and bottom pan gaskets have been updated to include the new silicone beaded gaskets.

Parts are currently available from GMSPO.

SERVICE MANUAL REFERENCE:

Whenever replacement and/or installation of a side cover or bottom pan gasket on any HYDRA-MATIC 3T40 is necessary, refer to the unit repair section of your service manual.

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.