A/T - Pedal Buzz At Zero to Light Throttle

91pontiac04

Bulletin Number: 91-7-9A
Reference Number: 077126R
Publish Date: 3/91


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

Models Affected:
1990-91 SUNBIRD W/3.1L, GRAND AM AND GRAND PRIX 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. This bulletin cancels and replaces bulletin 91-7-9 issued 9/90.

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:

This new spacer plate went 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 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
" " 8678489 - KKC
" " 8678488 - KNC
" " 8678038 - KXC (1991 Only)
" " 8678163 - LJC
" " 8678164 - LKC
" " " " - LLC

Parts are currently available from GMSPO.

SERVICE MANUAL 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.