A/T Oil Pan Gasket - Revised to Eliminate Fluid Leaks
Bulletin 86-7200-4Date
Jan. '87
Ref. No. 86-195-7200
SUBJECT: NEW CELLULOSE COATED OIL PAN GASKET TO ELIMINATE FLUID LEAKS
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 200C 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.
FIGURE 1 - THM 200C TRANSMISSION I. D. NAMEPLATE YPSILANTI, MICHIGAN:
FIGURE 2 - THM 200-4R TRANSMISSION I.D. NAMEPLATE THREE RIVERS, MICHIGAN:
Date Of Production Change: (Figures 1 and 2)
THM 200C: 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 Information:
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 ft.lbs.) and all THM 200C hex head screws 10-16 N-m (7-12 ft.lbs.). NOTE: The THM 200C pan torque specifications have recently been
changed from 8-14 N-m (7-12 ft.lbs.). Please update Page 200C-43 of your 1987 THM 200C Unit Repair Section to reflect this change.