PEDAL BUZZ AT ZERO TO LIGHT THROTTLE IN FORWARD GEAR

TRANSMISSION APPLICATIONS: 3T40, 3.1L, 2.3L

SUBJECT: PEDAL BUZZ AT ZERO TO LIGHT THROTTLE IN FORWARD GEAR RANGES (NEW SPACER PLATE

TRANSMISSION MODELS:

VEHICLE APPLICATIONS: 1990-91 J,L W/3.1L, N,W W/2.3L, 3T40

* This bulletin has been revised to include serial number information stated under section "DATE OF PRODUCTION CHANGE". Part numbers have been updated.

Bulletin Covers:

A new Spacer Plate (20) with a smaller 1-2 accumulator orifice which will reduce the potential for pedal buzz. This pedal buzz is noticeable at zero to light throttle in forward gear ranges caused by unstable operation of the 1-2 accumulator valve.

DATE OF PRODUCTION CHANGE:

The new Spacer Plate will go into Production in all "K" and "L" model HYDRA-MATIC 3T40 transaxles for the 1991 model year on July 30, 1990 (Julian Date 211).

NOTE: 1991 KKC model transaxles with serial numbers built between 1011 - 1830 and built after July 30, 1990 (Julian Date 211) are also affected.

SERVICE PROCEDURE:

To service any HYDRA-MATIC 3T40 for a pedal buzz condition, replace the (existing) spacer plate with a new spacer plate which contains the smaller 1-2 accumulator orifice.

SERVICE PARTS INFORMATION:

Refer to the following part numbers whenever ordering this new spacer plate.

Package Description Part Number and Transaxle Model ------------------- -------------------------------- Spacer Plate 8678035 - KDC Spacer Plate 8678489 - KKC Spacer Plate 8678488 - KNC Spacer Plate 8678038 - KXC (1991 Only) Spacer Plate 8678163 - LJC Spacer Plate 8678164 - LKC Spacer Plate 8678164 - LLC

SERVICE MANUALS REFERENCE:

Whenever service to the Spacer Plate or valve body assembly is necessary, refer to the HYDRA-MATIC 3T40 Unit Repair Section of your service manual.

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.