NEW BOTTOM PAN/CONTROLLED COMP PAN GASKET AND SERVICE INFO.

SUBJECT: NEW BOTTOM PAN AND CONTROLLED COMPRESSION BOTTOM PAN GASKET FOR 1985-1990 DE VILLES AND FLEETWOODS, 1986-1990 ELDORADOS AND SEVILLES, AND 1987-1992 ALLANTES

A new transaxle bottom pan having a flat face along the pan rail and controlled compression bottom pan gasket has been released for all Hydra-Matic 4T60 and THM F-7 transaxles. The new pan must be used with the new gasket. This bottom pan and gasket assembly was designed to reduce the potential of bottom pan leaks. The new gasket is black in color and has a rubber-like texture. The controlled compression gasket is designed to be a reusable gasket.

The controlled compression bottom pan gasket went into production on June 24, 1991 (Julian Date 175) for all Hydra-Matic 4T60 and THM F-7 transaxles. Refer to Figure 1.

This new controlled compression bottom pan gasket can be used on all previous Hydra-Matic 4T60 and F-7 transaxles when used with the new bottom pan and flanged hex head bolt. The old style conical washer screw can be used with the new bottom pan and controlled compression gasket, but the new flanged hex head bolt cannot be used on the old style bottom pan and gasket combination. Refer to Figure 2.

This new controlled compression bottom pan gasket does not supersede the old style bottom pan gasket. It is recommended for use only on transaxles with a repeat leak condition.

Bottom Pan Gasket Replacement:

1. Clean sealing surface of the bottom pan and machined surface of the transaxle case. If gasket is being reused, inspect the surface for damage and replace if needed. All mating surfaces must be clean and free of transaxle fluid.

2. Carefully align the bottom pan bolt holes with the gasket and transaxle case mounting holes. Install all bolts by hand and torque to 17 N.m (151 lbs. in.).

NOTE: If the controlled compression gasket is being reused, clean the surface with a soft cloth. Use of solvents may cause damage to the gasket and affect its durability.

Whenever ordering this new controlled compression gasket, refer to the following part numbers:

Service P/N Description (Package Contents) Models ----------- ------------------------------ ------ 8675995 Transaxle Bottom Pan Package: 4T60(44O-T4) (1) Pan, Transaxle Oil (1) Gasket, Transaxle Oil Pan (19) Bolt, Flanged Metric Hex Head (1) Magnet, Chip Collector

8675996 Transaxle Bottom Pan Package: F-7 (1) Pan, Transaxle Oil (1) Gasket, Transaxle Oil Pan (19) Bolt, Flanged Metric Hex Head (1) Magnet, Chip Collector

8678681 Transaxle Bottom Pan Gasket, 4T60 and F-7 Controlled Compression

Parts are currently available from GMSPO.

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