For 1990-2009 cars

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

#### NOTICE:

This bulletin supersedes Product Service Bulletin 86-7200-106 which should be destroyed.

#### BULLETIN COVERS:

New design "feed/bleed" system for the forward clutch. This system gives more cushioning during forward clutch apply and can be used on certain past models to reduce a harsh PARK/NEUTRAL to DRIVE engagement.

DATE OF PRODUCTION CHANGE: (Figures I and 2)

April 25, 1986 (Julian date 115), the following changes were introduced for all THM 200-4R models (excluding BRF).

Forward clutch assembly, minus check ball in housing (618) Forward clutch piston assembly (622) Additional waved plate (666) Front internal gear (633)

#### SERVICE ACTION:

1981-86 Models Built Prior To April 25, 1986 (Julian date 115).

If a vehicle equipped with a THM 200-4R transmission built prior to April 25, 1986 (Julian date 115) exhibits a harsh Park/Neutral to Drive engagement, install the Service Package listed in Service Parts Information.

NCTICE: This system cannot be used on 1986-1987 BRF, 1984-1985 BQ and 1983 BR model.

1986-87 Models Built On Or After April 25, 1986 (Julian date 115).

#### Models built after implementation of the feed/bleed system can be serviced with indiviqual parts.

#### Important: When servicing the forward clutch, select the correct backing plate (627). Backing plate selection affects piston travel, shift feel and clutch durability.

Backing Plate Selection: (Clutch Fully Assembled) Apply an evenly distributed load in the direction indicated in Figure 3 to remove slack from the clutch assembly. Use 20 lbs. (9 kg) of pressure against the backing plate--excessive pressure will cause an inaccurate measurement. With the clutch assembly compressed, use a feeler gage to measure the distance between the backing plate and snap ring. Correct backing plate travel is 0.7mm-1.5mm (0.028"-D.059"#). Refer to Figure 4 for backing plate identification information.

SERVICE PARTS INFORMATION:

8639943 Neutral Drive Shift Package (Contains Forward Clutch Assembly Complete, Front Internal Gear and Thrust Washer)

For models built on or after April 25, 1986, (Julian date 115), refer to the current Service Parts Catalog for separately available part numbers.

#### SERVICE NOTES:

Earlier design front internal gears (Service Package Number 8630909) cannot be used with THM 200-4R models built after Apri1 25, 1986 (Julian date 115).

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.