A/T - Harsh Garage Shift from Reverse to Drive
File In Section: 7 - TransmissionBulletin No.: 77-71-60A
Date: September, 1997
Subject:
Harsh Garage Shift Reverse to Drive
(Install New Valve Body Spacer Plate and Reflash PCM)
Models:
1997 Buick Park Avenue, Riviera
1997 Oldsmobile LSS
1997 Pontiac Grand Prix, Bonneville SSEi with 3.8L Engine (VINs 1, K - RPOs L67, L36) and HYDRA-MATIC 4T65-E Transaxle (RPOs MN3, MN7)
This bulletin is being revised to correct a new calibration number. Please discard Corporate Bulletin Number 77-71-60 (Section 7 - Transmission).
Condition
Some customers of vehicles equipped with a Hydra-matic 4T65-E transaxle produced before December 16, 1996 may comment about a harsh garage shift sometimes described as a delayed or harsh engagement from reverse to drive.
Cause
This condition may be due to a combination of valve body spacer plate orifice size and calibration of this shift maneuver.
Correction
The vehicle assembly plants started producing vehicles with transaxles that contain an enhanced garage shift package on December 16, 1996 to improve the reverse to drive garage shift feel. In order to correct this 6ondition on a customer's vehicle produced prior to December 16, 1996 it will be necessary to install a new valve body spacer plate which has an orifice size change and reflash the calibration in the PCM.
Service Information
Vehicles produced before December 16, 1996 did NOT have this updated garage shift package. When the assembly plant introduced this change they changed the model numbers of the transaxle assemblies.
When servicing a 4T65-E transaxle for a harsh garage shift, it is important to note the model number and compare it to the chart below to verify if the repair should be performed.
Original Model Number Updated Model Number
Before December 1996 After December 1996
7FBB 8.8L (L67) 7BMB 3.8L (L67)
C/G CAR C/G CAR
7FHB 3.8L (L36) 7BDB 3.8L (L36)
C/G CAR C/G CAR
7XAB 3.8L (L67) W CAR 7HKB 3.8L (L67) W CAR
7YWB 3.8L (L67) H CAR 7MAB 3.8L (L67) H CAR
Parts Information
The following parts are currently available from GMSPO.
Part Number Description
24210495 Garage Shift Package, includes new
valve body spacer plate and gaskets
Calibration Cross Reference Table
A phone call will be required to properly reprogram a vehicle with the new calibration. Contact the Techline Customer Support Center (TCSC) at:
English 1 800 828 6860
French 1 800 503 3222
Inform the TCSC specialist that you are reconfiguring the vehicle due to the changes made to the transmission.
You will need the vehicle's VIN and the new calibration part number when you call TCSC. TCSC will provide you with a special number. The number is called a VCI which stands for Vehicle Configuration Index. This number is unique for each vehicle. The number will update the PCM with the new calibration. TCSC will also update their database so that a phone call will not be required after you receive your next CD ROM disc.
Once you have the number from TCSC, enter the Service Programming System, select SPECIAL and then Program by VCI. The correct calibration part number will be listed on the SPS summary screen. Continue with the programming process by selecting Program.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation Labor Time
K6570 Use published labor operation time
plus an "add time" of 0.4 hour to
PCM reprogramming.