Electra Park Avenue V6-231 3.8L VIN 3 FI (1988)
Drive Chain: All Technical Service Bulletins
A/T - 4T60/4T60E Drive Link Noise In Park/Neutral/Drive
Bulletin: 91-74T60-15
Date: August 91
Ref. No.: 91-231-74T60
Corp. Ref. No.: 077127
SUBJECT:
DRIVE LINK NOISE-IN PARK, NEUTRAL OR DRIVE (DIAGNOSE/REPLACE DRIVE SPROCKET BEARING)
MODELS AFFECTED: ALL WITH 4T60/4T60E TRANSAXLE
BULLETIN COVERS: (Figure 1)
Drive link diagnosis tips - all Hydra-Matic 4T60 and 4T60-E transaxles. Damaged drive link components may exhibit one of the following conditions:
1. A whine/whistle (that could even sound like generator whine) or growling noise in Park and Neutral that stops when the vehicle is put in Drive or
Reverse (with the vehicle not moving). When the vehicle is driven, this whine or growling noise (the noise may not be noticeable when the vehicle is
driven) increases and fades with vehicle speed and is most noticeable under light throttle acceleration. This whine/ whistle noise is usually caused by
a damaged drive sprocket support bearing (*516, for 4T60 **521 for 4T60-E). Replace the bearing if necessary.
*
Figure 1 shows Hydra-Matic 4T60 drive link components.
** Hydra-Matic 4T60-E item numbers not shown. Reference 4T60 components.
2. Noise under hard acceleration (drive link jumping sprocket teeth, rubbing on transaxle case or the driven sprocket support because of drive link
stretch).
IMPORTANT:
(Other vehicle related noises) --
