3-2 OR 2-1 COASTDOWN CLUNK SPACER PLATE INFORMATION

"Supersedes Dealer Technical Bulletin 83-T-17 Section 7. "

Some 1983 and 1984 THM 200-C model transmissions may experience a 3-2 and/or 2-1 coastdown clunk condition. This condition is most noticeable during the 3-2 downshift at approximately 18-20 miles per hour.

When servicing any 1983 or 1984 THM 200-C model transmission for 3-2 and/or 2-1 coastdown clunk refer to the service procedure below.

Service Procedure:

1. Check engine idle speed. This coastdown clunk is especially noticeable when the engine is cold.

2. Check rear differential back lash and correct if necessary.

3. If this coastdown clunk condition still exists, after checking the above stated service procedure on 1983 CN, CS, and HO models equipped with 2.8 litre V-6 engines, replace the valve body spacer plate with Part Number 8648303. On car service can be performed in changing the valve body spacer plate, refer to your service manual for proper installation procedure.

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.