OIL PAN GSK.FLUID LEAKS NEW CELLULOSE OIL PAN GSK.

MODELS AFFECTED: 1986 ELECTRA AND LESABRE ESTATE WAGONS AND REGALS EQUIPPED WITH 200C AND 200-4R AUTOMATIC TRANSMISSIONS

On the Julian dates listed below, all 1986 THM 200a and THM 200-4R transmissions were built using a new latex coated cellulose (hard fiber material) pan gasket. The new gaskets improve sealing capability by better withstanding fastener torques.

Date Of Production Change: (Figures 1 and 2) ------------------------- THM 20OC: May 29, 1986, Julian Date 149, New Cellulose coated transmission pan gasket implemented. THM 200-4R: June 23, 1986, Julian Date 174, New Cellulose coated transmission pan gasket implemented.

Service Action:

Any model year THM 200C and 200-4R transmissions with a continuous raised rib pan can be serviced with the new cellulose gaskets. When servicing a THM 200C or THM 200-4R which has the former flat surface pan, refer to Buick Service Bulletins 84-7200-4 (THM 200-4R) and 83-214 (THM 200C) for proper service procedures.

Some service overhaul packages may contain the latex coated cork (soft material) gasket, which should not be used on continuous raised rib pans. The new gasket can be ordered separately by ordering the appropriate part number listed below.

Service Parts Infomation:

8648529 THM 200C Gasket, Transmission Oil Pan (Cellulose) 8657387 THM 200-4R Gasket, Transmission Oil Pan (Cellulose)

Service Manual Reference:

Refer to the Automatic Transmission Unit Repair sections of the respective 1986 Service Manuals for proper installation procedures.

Service Notes:

When replacing the oil pan, it is critical that a torque wrench is used to tighten the hex head pan screws. Hand torque all THM 200-4R hex head screws 8-14 N.m (6-10 lb. ft.) and all THM 200C hex head screws 10-16 N.m (7-12 lb. ft. NOTE: The THM 200C pan torque specifications have recently been changed from 8-14 N.m (7-12 lb. ft.). Please update Page 200C-43 of your 1987 THM 200C Unit Repair Section to reflect this change.

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.