A/T - Moan/Whine Noise At 15-30 mph

TECHNICAL

Bulletin No.: 10-07-30-006B

Date: January 10, 2011

Subject: Transmission Moan/Whine Noise from Final Drive Carrier Assembly at Low Speeds 24-48 km/h (15-30 mph) (Perform Comparison Road Test, Repair As Outlined in Bulletin)

Models:
2007-2010 Buick Lucerne
2007-2010 Cadillac DTS
Equipped with 4T80E Automatic Transmission RPO FV3 or FV4
Vehicles Built Prior to February 1, 2010

Attention:
If you encounter a vehicle with this noise symptom built AFTER February 1, 2010 please refer to the latest version of PI0331.

Supercede:
This bulletin is being revised to add an Attention statement, clarify the Subject, change the final drive carrier assembly callout number in the Correction text and update two part descriptions in the Parts Information. Please discard Corporate Bulletin Number 10-07-30-006A (Section 07 - Transmission/Transaxle).

Condition

Some customers may comment on a moan or whine noise coming from the transmission in the 24-48 km/h (15-30 mph) range.

Cause

This condition may be caused by a whine from the final drive internal gear, final drive sun gear and the final drive carrier assembly.

Correction

1. The noise level should be evaluated at approximately 31 km/h (19 mph) with the radio OFF and the HVAC fan on speed 3. Compare the customer's vehicle to a like vehicle. If the customer's vehicle is not louder than the comparison vehicle and the noise can't be heard above a fan speed of 3 with the radio OFF, this may be a normal characteristic of the vehicle.








2. If the noise encountered is considered louder than a comparison vehicle, replace the transmission final drive internal gear (120), final drive sun gear (121) and final drive carrier assembly (100). Refer to Final Drive Assembly Replacement, Case Extension Replacement and Final Drive Internal Gear Replacement in SI.

3.11 Final Drive Ratio (FV3)
- Final Drive Internal Gear (120), P/N 08677862
- Final Drive Sun Gear (121), P/N 24256733
- Final Drive Carrier Assembly (100), P/N 24256635

3.71 Final Drive Ratio (FV4)
- Final Drive Internal Gear (120), P/N 08677862
- Final Drive Sun Gear (121), P/N 24256732
- Final Drive Carrier Assembly (100), P/N 24256632

Parts Information





Warranty Information





For vehicles repaired under warranty, use the table.





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