Bonneville V6-231 3.8L VIN 3 SFI (1988)
Band: All Technical Service Bulletins
A/T - Intermittent Loss of Drive
Bulletin Number:
90-7-3
Reference Number:
977120R
Publish Date:
9/89
Figure 1 - THM 440-T4/THM F-7 Transaxle Identification Information
Subject:
INTERMITTENT LOSS OF DRIVE (CHECK 1-2 BAND APPLY/NEW SERVICE TOOL)
Models
Affected:
1984-90 6000, BONNEVILLE, GRAND PRIX MODELS WITH 4T60, F-7
BULLETIN COVERS:
(Figure 1)
A vehicle equipped with a THM 440-T4/HYDRA-MATIC 4T60 or THM F-7 may experience an intermittent loss of Drive. This may be caused by the
1-2 band stop (139) being below specification allowing the band to shift off location causing the 1-2 Band Apply Pin to miss the Band while stroking,
creating a loss of drive. The vehicle will still have Reverse gear. If there is no Forward and Reverse gear, then it is most likely a damaged input clutch
sprag assembly.
Figure 2 - Removal Of Bottom Case Components
