NEW DESIGN FORWARD CLUTCH SMOOTHER PK./NEUT. TO DRIVE

MODELS AFFECTED: 1982-1987 RWD DE VILLE AND BROUGHAM

Some 1982-1987 RWD De Villes and Broughams may exhibit harsh park/neutral-to-drive engagement feel. A new design feed/bleed system for the forward clutch, which gives more cushioning during clutch apply, was introduced in production on April 25, 1986 (Julian Date 115), for all THM200-4R transmissions.

The new system includes the following component changes:

- Forward clutch assembly, minus check ball in housing - New forward clutch piston assembly - Additional wave plate - New front internal gear

To repair a condition of harsh park/neutral-to-drive engagement, the following service parts have been released:

Breakpoint Part Number Description ---------- ----------- ----------- Built Before April 25, 1986 8639943 Forward clutch assembly complete, (Julian Date 115) front internal gear and thrust washer.

Built After April 25, 1986 8657257 Forward clutch assembly complete, (Julian Date 115) 8639947 Front internal gear and thrust washer (Can be used on all model years)

NOTE: Earlier design front internal gears, (Service Package P/N 8630909), cannot be used with THM200-4R models built after April 25, 1986 (Julian Date 115).

When servicing a 200-4R transmission of the second design, it is important to select the correct backing plate. Backing plate selection affects piston travel, shift feel and clutch durability. To select the backing plate, assemble the clutch pack using the original backing plate and apply approximately 20 lbs. of pressure to the backing plate. This will assure full contact of all the elements without compressing the wave plates. With the clutch compressed, use a feeler gauge to measure the clearance between the backing plate and the snap ring (refer to Figure 1). If clearance is greater than 1.5mm (.059") use the next thicker backing plate. If the clearance is less than .7mm (.028") use the thinner plate. Refer to Figure 2 for backing plate identification information.

For models built on or after April 25, 1986 (Julian Date 115), refer to the current GMSPO catalog for separately available part numbers.

Refer to the appropriate Service Information Manual for repair procedures.

For warranty purposes, use Labor Operation K7200 at 3.5 hours.

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.