MODULATOR BUZZ NOISE INSTALL ORIFICE CUP PLUG P/N

MODELS AFFECTED: 1986-1987 DE VILLE, FLEETWOOD, ELDORADO AND SEVILLE

Some 1986-1987 De Villes, Fleetwoods, Eldorados and Sevilles equipped with 440-T4 transaxles built prior to February 1, 1987 (Julian Date 032), may exhibit a buzzing noise from the transaxle.

This buzzing sound may be caused by a missing orifice cup plug in the modulator circuit of the channel plate. This orifice cup plug was required with the change to the altitude compensated (aneroid) modulator.

To repair this condition, remove the transaxle and channel plate and insert the cup plug from the service package listed below (See Figure 1). Press the cup plug flush to .5mm below the surface.

Part Number Description

8646987 Service Package: Orificed Cup Plug, Lower and Upper Channel Plate Gasket, Modulator Port Gasket and Instruction Sheet

For warranty purposes, use Labor Operation number K7460 for C-Car at 5.5 Hours and E/K Car at 6.1 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.