Corsica V6-191 3.1L (1990)
Clutch: All Technical Service Bulletins
A/T - Revised Direct Clutch Housing
Number:
90-63-7A
Section:
7A
Date:
September 1989
Corporate Bulletin No.: 977141
Subject:
NEW DIRECT CLUTCH HOUSING
Model and Year:
1990 A, J, L, W CARS
TO:
ALL CHEVROLET DEALERS
A new Direct Clutch Drum (610) with an increased wall thickness of 0.2 mm (Figure 1) to prevent the Direct Clutch Drum from warping when subjected
to excessive heat caused by an Intermediate Band distress (606).
The new Direct Clutch drum went into production July 11, 1989, (Julian Date 192) for all Willow Run built transaxles and July 12, 1989, (Julian Date
193) for all Windsor built HYDRA-MATIC 3T40 transaxles.
This new Direct Clutch Drum can be used on previous model HYDRA-MATIC 3T40 transaxles built since (model year) Start of Production - 1985.
Do not attempt to use the new Direct Drum in transaxles built previous to model year 1985 because the return spring and snap ring groove location will
not allow 1980 to 1985 model internal components to assemble into the new direct clutch drum.