A buzzing noise and possible delayed upshifts may be noticed on some 1982 THM 700-R4 transmissions if the gaskets (control valve assembly to spacer plate and spacer plate to case), currently released for service in 1983, are used with the original control valve assembly and spacer plate.
When servicing any THM 700-R4 transmission that necessitates the replacement of the gaskets (control valve assembly to spacer plate and spacer plate to case) order service package 8642993, and inspect for control valve assembly spacer plate identification. If the control valve assembly spacer plate identification is letter 'A', the spacer plate must be replaced also, to avoid the buzzing noise and possible delayed upshifts.
Service Package Number 8642993 Contains:
1 - Gasket, Control Valve Assembly To Spacer Plate 1 - Gasket, Spacer Plate To Case 1 - Instruction Sheet
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.