For 1990-2009 cars

# SOFT 1-2 AND 2-3 SHIFTS NEW PARTS AVAILABLE

#### MODELS AFFECTED: 1979 SEVILLES 1980-1984 DEVILLES AND BROUGHAMS 1982-1984 ELDORADOS ANDSEVILLES

1979 through 1984 Cadillacs equipped with a THM 200C, 200-4R or 325-4L transmission may exhibit soft 1-2 and 2-3 upshifts. This condition may be caused by a hydraulic leak in the seal areas of the intermediate servo outer piston. The affected Cadillac vehicles which may experience this condition are as follows:

Year(s) Vehicle(s) Transmission/Model(s) ------ ----------- --------------------- 1979 Seville THM 20OC/AX 1980-1981 Deville and Brougham THM 20OC/AS 1981-1984 Deville and Brougham THM 200-4R/AA, BY and OM 1982-1984 Eldorado and Seville THM 325-4L/AJ, AL, AM and AE

Beginning in January, 1984, all models of THM 200C, 200-4R and 325-4L transmissions are being produced using a new intermediate servo outer piston that has rubber lip seals in place of the past scarf cut Teflon ring seals (refer to illustrations). When servicing any of the above listed transmissions for a soft 1-2 and 2-3 upshifts condition, replace the scarf cut seals equipped intermediate servo outer piston with the appropriate new rubber lip seals piston listed below:

Servo Piston Kit P/N's (Includes New Piston and Rubber Lip Seals)

Year(s) Transmission/Model(s) Outer Piston -------- --------------------- ------------ 1979-1980 THM 20OC/AX and AS 8638936 1981 THM 20OC/AS 8638937 1981 -1984 THM 200-4R/AA, BY and OM 8632980 1982-1984 THM 325-4L/AJ, AL, AM and AE 8632980

#### NOTE: The new rubber lip seals must not be installed on past intermediate servo outer pistons or past Teflon seals on new pistons.

The new rubber seals are also available separately in a service package (P/N 8638941) consisting of two rubber lip seals and a servo cover "O" ring.

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.