COASTDOWN CLUNK/THM200-C NEW CONTROL VALVE ASSEMBLY

SOME 1982-83 'F' SERIES VEHICLES EQUIPPED WITH 200-C TRANSMISSION AND 2.8 LITRE V-6 ENGINES MAY EXPERIENCE A 302 AND/OR 2-1 COAST- DOWN CLUNK CONDITION. THIS CONDITION IS MOST NOTICEABLE DURING THE 3-2 DOWNSHIFT AT APPROXIMATELY 28-32 K.P.H. (18-20 M.P.H.). BEGINNING IN EARLY NOVEMBER, TWO NEW TRANSMISSION ASSEMBLIES ('CS' AND 'HO' CODES) WENT INTO PRODUCTION FOR THE 2.8 LITRE V-6 ENGINES TO ELIMINATE THIS CLUNK CONDITION. WHEN SERVICING ANY 1982 AND 1983 THM 200-C MODEL TRANSMISSION WITH THIS CLUNK CONDITION, REPLACE THE CONTROL VALVE ASSEMBLY WITH PART NO. 8648100. ON CAR SERVICE CAN BE PERFORMED IN CHANGING THE CONTROL VALVE ASSEMBLY. REFER TO YOUR SERVICE MANUAL FOR THE 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.