OIL PAN/VALVE BODY COVER LEAK NEW PAN / VALVE BODY COVER

MODELS AFFECTED: ALL THM 125/125C TRANSAXLES

The THM 125/125C transaxle oil pan and valve body cover have been changed to improve sealing in these areas. The new oil pan (Part No. 8643574) and valve body cover (Part No. 8643575) are thicker and have a raised continuous rib on the flange. (See Figure 1).

The new transaxle oil pan requires a new thicker oil pan gasket (Part No. 8643572). The new valve body cover also requires a new gasket (Part No. 8631340). New hex head bolts with conical washer (Part No. 8643879) are to be used with both the oil pan and valve body cover (Figure 2).

Service Information

1. If a leak occurs on THM 125/125C transaxle refer to your service manual for diagnostic and disassembly/assembly procedures.

2. If the oil leak is in the transaxle oil pan or valve body cover area visually inspect the transaxle to determine if the new design parts have been used.

If the unit is of the old design, order service package Part No. 8653942 to correct oil leask in the oil pan area or service package Part No. 8653943 to correct an oil leak in the valve body cover area. These packages contain the following:

Part No. 8653942 Part No. 8653943

Qty. Descriptim Part No. Qty. Description Part No.

1 Pan, Transaxle Oil 8643574 1 Cover, Valve Body 8643575 1 Gasket, Transaxle 8643572 1 Gasket, Valve Body 8631340 Oil Pan Cover 16 Assembly, Hex Head 8643879 11 Assembly, Hex Head 8643879 Screw & Conical Washer Screw & Conical Washer 1 Instruction Sheet 1 Instruction Sheet

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 transaxle oil pan or valve body cover oil leaks may result.

4. When assembling the oil pan or valve body caver follow procedures outlined in the service manual. Do not use impact tools or over torque attaching bolts. Over-torquing may result in split or cracked gaskets. Bolts should be torqued 8-14 N.m (6-10 Ft lbs.).

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.