TRANS. OIL PAN/ GASKET LEAK NEW PAN, GASKET, BOLTS/325-4L

Models Affected: All THM 325-4L

The THM 325-4L transmissim oil pan has been changed to improve the seal between the oil pan and transmission case. The new transmission oil pan (Part No. 8635854) is thicker and has a continuous rib on the flange. (See Figure 1)

The new transmission oil pan requires a new thicker oil pan gasket (Part No. 8635884) and hex screw and conical washer assembly, (Part No. 8643693). (See Figure 2.)

Service Information

1. If a leak occurs refer to your service manual for diagnostic and disassembly/assembly procedures.

2. If the oil leak is in the transmission oil pan area visually inspect the oil pan and bolts to determine if the new design parts have been used.

If the unit is of the old design, you may need to order service parts listed below:

1 - Pan, Transmission Oil 8635854 1 - Gasket, Transmission Oil Pan 8635884 15 - Assembly, Hex Head Screw and 8643693 Conical Washer (Bolts)

If new design parts were used, you may only need the gasket and bolts or the gasket alone.

3. Do not use R.T.V. with the new transmissim oil pan.

4. When assembling the oil pan follow your service manual procedures and take particular care not to over-torque the bolts. Over-torquing may result in split or cracked gaskets. Bolts should be torqued to 11 N.m (8 Ft-lbs).

5. Service Package No. 8635959 incorporating the parts listed above will be available approximately November 1, 1983.

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.