Some 1985-1989 DeVilles and Fleetwoods, 1986-1989 Eldorados and Sevilles, or 1987-1989 Allantes may experience transmission fluid leaks at the side cover due to crushing or splitting of the gasket when the cover nuts are torqued during assembly. The new side cover to channel plate gasket uses a latex coated cellulose which resists crushing and splitting. As of November 1, 1988 (Julian Date 306), all THM 440-T4/HYDRA-NUTIC 4T60 and THM F-7 models have been built with the new gasket.
In addition, changes to the THM F-7 transaxle bottom pan include a revised design which uses a continuous raised rib on the pan rail in combination with the latex coated cellulose gasket. These changes were made in production on January 30, 1989 (Julian Date 030) and were made previously on the THM 440-T4/HYDRA-MATIC 4T60.
Service Parts Information:
Description P/N Usage ----------- --- ----- Package Side Cover Gaskets Kit - 8644902 1985-1989 THM 440/4T60 & THM F-7 Gasket, Side Cover to Case Gasket, Side Cover to Channel Plate
The new latex coated cellulose side cover gasket will be available for service once the previous gasket stock has been used up. The gasket will not be available separately but can be obtained by ordering the Side Cover Gasket Kit Package or the Complete Overhaul Repair Package.
Bottom Pan Package - THM F-7 8661917 1987-1989
Gasket, Bottom Pan (Latex Coated Cellulose) Bottom Pan Chip Collector Magnet Gasket, Bottom Pan - THN4 F-7 8668028 1987-1989 (Latex Coated Cellulose)
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.