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

BEGINNING IN MAY 1983, THE THM 325-4L TRANSMISSION OIL PAN WAS CHANGED TO IMPROVE THE SEAL BETWEEN THE OIL PAN AND TRANSMISSION CASE. THE NEW TRANSMISSION OIL PAN (P/N 8635854) IS THICKER AND HAS A CONTINUOUS RIB ON THE FLANGE, SEE FIGURE 1. THE NEW TRANSMISSION OIL PAN REQUIRES A NEW OIL PAN GASKET (P/N 8635884) THAT IS THICKER AND HEX HEAD SCREW AND CONICAL WASHER ASSEMBLY, I.E., BOLTS (PART NUMBER 8643693). SEE FIGURE 2. SERVICE INFORMATION: 1. IF A LEAK OCCURS REFER TO YOUR SERVICE MANUAL FOR DIAGNOSTIC AND DISASSEMBLY/ASSEMBLY PROCEDURES. 2. WHEN SERVICING ANY THM 325-4L TRANSMISSION FOR A LEAK IN THE TRANSMISSION OIL PAN AREA, VISUALLY INSPECT THE OIL PAN AND BOLTS TO DETERMINE IF THE NEW DESIGNS HAVE BEEN USED. 3. IF THE TRANSMISSION WAS BUILT BEFORE MID-MAY 1983, 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) 4. IF THE TRANSMISSION WAS BUILT AFTER MID-MAY 1983, YOU MAY ONLY NEED THE GASKET AND BOLTS OR THE GASKET ALONE. 5. DO NOT USE R.T.V. WITH THE NEW TRANSMISSION OIL PAN. 6. WHEN ASSEMBLING THE OIL PAN FOLLOW YOUR SERVICE MANUAL PROCEDURE 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 NM (8 FT.LBS.). 7. SERVICE PACKAGE NO. 8635959 WILL BE AVAILABLE IN THE NEAR FUTURE TO SERVICE TRANSMISSIONS BUILT PRIOR TO MID-MAY 1983. (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.