TRANS. OIL EXHAUSTING OUT VENT SERVICE REPLACEMENT PARTS

VEHICLES AFFECTED: 1983-84 Vehicles Equipped With THM 200-C Transmissions

If a 1983 or 1984 THM 200-C transmission exhibits oil exhausting out the vent pipe, possible causes may be due to out-of-flat conditions on the face, nicked faces, porosity, or face damage on the Pump Body Assembly or the Oil Pump Cover Assembly.

When servicing any 1983 or 1984 THM 200-C transmission for transmission oil exhausting out the vent pipe, both the Pump Body Assembly and the Pump Cover assembly should be replaced. At the same time, a new Pump to Case gasket should also be installed. Replacement of these parts will prevent transmission oil from exhausting out the vent pipe during harsh deceleration or during sharp turns.

The following part numbers can be used to service all these THM 200-C transmissions.

Pump Body Assembly

Models Order Service Part ------ ------------------ BH,PS,CZ,JY, OI,OR,OU 8638922

Oil Pump Cover

Models Order Service Part ------ ------------------ CZ,JY 8633956

OR,OU 8633957

BH,PS,OI 8633958

Pump to Case Gasket

Models Order Service Part ------ ------------------ BH,PS,CZ,JY, OI,OR,OU 8633899

Refer to your service manual for disassembly and reassembly procedures.

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.