A/T - 4T60 New Input and 3RD Clutch Piston Seal
90chevy27Number: 91-53-7A
Section: 7A
Date: August 1990
Corp. Bulletin No.: 077124
Subject: NEW INPUT INNER SEAL AND 3RD CLUTCH INNER PISTON SEAL
Model and Year: 1984-90 CELEBRITY AND 1990-91 LUMINA WITH 4T60 AUTOMATIC TRANSMISSION
Figure 1:
TO: ALL CHEVROLET DEALERS
BULLETIN COVERS: (Figure 1)
New input and 3rd clutch inner piston seals for a vehicle equipped with a 1990-91 HYDRA-MATIC 4T60 transaxles. The new seals are both made from VAMAC material(R). The 3rd clutch inner piston seal is identical to the previous but does not have the hash marks. The new input inner piston seal is a short lip design.
DATE OF PRODUCTION CHANGE:
Beginning December 18, 1989 (Julian Date 352), all 1990-91 HYDRA-MATIC 4T60 transaxles have been built using the short lip design for the input inner piston seal and
VAMAC ( R)material for the input/3rd inner piston seals.
SERVICE PARTS INFORMATION:
Short lip seals and the VAMAC material seals are interchangeable with the current seals. These new seals will service all 1984 through 1991 models. The new design will replace the current seal in service packages as stock is depleted.
SERVICE MANUAL REFERENCE:
Refer to the appropriate 1984 through 1991 Service Manuals for proper disassembly and assembly procedures. We believe this source and their product to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources."