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

BEGINNING IN SEPTEMBER, 1983, THE THM 125/125-C TRANSAXLE WENT INTO PRODUCTION USING A NEW OIL PAN AND VALVE BODY COVER. THIS NEW OIL PAN (PART NO. 8643574) AND VALVE BODY COVER (P/N 8643575) ARE THICKER AND HAVE A RAISED, CONTINUOUS RIB ON THE FLANGE (FIGURE 1). THE NEW OIL PAN REQUIRES A NEW GASKET (P/N 8643572). THE NEW VALVE BODY COVER ALSO REQUIRES A NEW GASKET (P/N 8631340). NEW HEX HEAD BOLTS WITH CONICAL WASHERS (P/N 8643879) ARE TO BE USED WITH BOTH THE OIL PAN AND VALVE BODY COVER (FIGURE 2). SERVICE INFORMATION: 1. IF A LEAK OCCURS, REFER TO YOUR SERVICE MANUAL FOR DIAGNOSTIC AND DISASSEMBLY/REASSEMBLY PROCEDURES. 2. WHEN SERVICING ANY THM 125/125C TRANSAXLE FOR A LEAK IN THE OIL PAN OR VALVE BODY COVER AREA, VISUALLY INSPECT THE OIL PAN AND VALVE BODY COVER BOLTS TO DETERMINE IF THE NEW PARTS HAVE BEEN INSTALLED. (FIGURE 2). 3. IF THE TRANSAXLE WAS BUILT PRIOR TO SEPTEMBER 1983, ORDER SERVICE PACKAGE 8653942 TO CORRECT A LEAK IN THE OIL PAN AREA, OR SERVICE PACKAGE 8653943 TO CORRECT A LEAK IN THE VALVE BODY COVER AREA. THESE PACKAGES CONTAIN: 8653942 8653943 QTY. DESCRIPTION P/N QTY. DESCRIPTION P/N 1 PAN,TRANSAXLE OIL 8643574 1 COVER,VALVE BODY 8643575 1 GASKET,TRANSAXLE 8643572 1 GASKET,VALVE BODY 8631340 OIL PAN 16 ASSEMBLY,HEX HEAD 8643879 11 ASSEMBLY,HEX HEAD 8643879 SCREW AND CONICAL SCREW AND CONICAL WASHER WASHER 1 INSTRUCTION SHEET 1 INSTRUCTION SHEET

4. IF THE TRANSAXLE WAS BUILT AFTER SEPTEMBER, 1983, THE GASKET, BOLTS, OIL PAN AND/OR VALVE BODY COVER CAN BE ORDERED SEPARATELY. 5. DO NOT USE R.T.V. WITH THE NEW TRANSAXLE OIL PAN OR VALVE BODY COVER. OIL LEAKS MAY RESULT. 6. WHEN ASSEMBLING THE OIL PAN OR VALVE BODY COVER, FOLLOW PROCEDURE OUTLINED IN YOUR SERVICE MANUAL. DO NOT USE IMPACT TOOL OR OVER- TORQUE ATTACHING BOLTS. OVER-TORQUING MAY RESULT IN SPLIT OR CRACKED GASKETS. BOLTS SHOULD BE TORQUED TO 8-14 N-M (6-10 FT. LBS.). (SEE ILLUSTRATION)

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.