All 1987 THM 40O/475 transmissions have a new latex-coated cellulose (hard, fiber material) pan gasket. The new gasket improves sealing because it will not "crush" like a cork (soft material) gasket.
DATE OF CHANGE: (Figure No.1) --------------- July 22, 1986 (Julian Date 203) for all 1987 THM 400/475 transmission models.
The previous latex-coated cork (soft material) gasket, in some service overhaul packages, should NOT be used. The new gasket is available separately and can be used on any model year THM 400/475 transmission.
Part Number Description ----------- ----------- 8655625 Gasket, Transmission Oil Pan (Cellulose)
Refer to the Oil Pan and Filter Assembly section of the 1987 THM 400 Unit Repair Service Manual for proper installation proce- dures.
When installing the oil pan you must use a torque wrench to tighten the conical washer and screw assemblies to 8-14 Nm (6-10 ft lb).
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.