Malibu V6-3.5L VIN 8 (2004)
Channel Plate: Customer Interest
A/T - 4T45E Growl/Howl on Moderate Acceleration
Bulletin No.: 04-07-30-021A
Date: July 02, 2004
ADVANCE SERVICE INFORMATION RESOLUTION
Subject:
Growl or Howl Type Noise From Transmission/Engine Compartment During Light to Moderate Acceleration from a Stop (Replace Drive Link, Drive
Sprocket and Driven Sprocket)
Models:
2004 Chevrolet Malibu, Malibu Maxx
2004 Oldsmobile Alero
2004 Pontiac Grand Am
Built After January 16, 2004
with 4T45E Automatic Transaxles (RPO MN5) Built Between Julian Date 4016 and 4126 and 3.4L or 3.5L V6 Engine (VINs E, 8 - RPOs LA1, LX9)
Supercede:
This bulletin is being revised to include a repair procedure and parts availability information. Please discard Corporate Bulletin Number 04-07-30-021
(Section 07-Transmission/Transaxle).
Condition
Some customers may comment on a growl or howl type noise during light to moderate acceleration from a stop. This noise is load and engine RPM
sensitive and will occur between 1500 RPM to approximately 2300 RPM. The noise is most noticeable in first and second gear. The noise may dissipate
prior to the 1-2 shift, but will be noticed again in second gear depending on the load and engine RPM. The pitch of the noise will change during the 1-2
shift.
Cause
The noise is due to the new 5/8 inch drive link assembly being at a resonant frequency during certain driving conditions.
Correction
Important:
Only RPO MN5 transaxles built between Julian date 4016 and 4126 have 5/8 inch drive link assemblies. Refer to Transmission ID and VIN
Derivative Location, for Julian date location information.
Follow the service procedure below to replace the 5/8 inch drive link and sprockets with a 7/8 inch drive link and sprockets.
1.
Remove the transaxle from the vehicle.
2.
Install the transaxle in the bench support fixture.
3.
Remove the torque converter.
4.
Remove the Park Neutral Position (PNP) switch.
5.
Remove the side cover transmission mount bracket from the transmission.
6.
Remove the control valve side cover.
7.
Remove the wiring harness from the valve body and solenoids.
Important:
^
It is not necessary to remove either the valve body or the oil pump from the channel plate assembly.
