NEW INPUT INNER SEAL 440-T4 SHORTLIP & 3RD CLUTCH DESIGN

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

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? 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 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."

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.