1987 - 1991 Corvette: Service Bulletin: New 3-4 Club Plates for 4L60 Transmissions

Subject: NEW 3-4 CLUTCH PLATES (STEEL) 4L60 TRANSMISSIONS
Model and Year:
1987-91 CAPRICE, CAMARO, CORVETTE WITH 4L60 AUTOMATIC TRANSMISSION
1987-91 C/K, G, M, RN, S/T TRUCK
1990-91 L TRUCK WITH 4L60 AUTOMATIC TRANSMISSION
Source: Chevrolet Service Bulletin
Bulletin Number: 91-112-7A - (11/09/1990)

TO: ALL CHEVROLET DEALERS

BULLETIN COVERS:

New 3-4 clutch plates (steel) are available for 1987-1990 HYDRA-MATIC 4L60 transmissions. The new clutch plates have a slightly smaller outer radius to let them move more freely in the clutch housing.

DATE OF PRODUCTION CHANGE:

Beginning July 27, 1990 (Julian Date 208), all HYDRA-MATIC 4L60 transmissions were built using the new 3-4 clutch plates.

SERVICE INFORMATION:

The new 3-4 clutch plates can be used to service any HYDRA-MATIC 4L60 transmission produced after February 9, 1987 (Julian Date 040).

SERVICE PARTS INFORMATION:

Description New Part ----------- -------- Plate - 3rd and 4th (steel - 4 or 5 needed) 8678053 Plate - 3rd and 4th (steel - 1 needed) 8678054 Parts are currently available from GMSPO.

SERVICE MANUAL REFERENCE:

Refer to the Automatic Transmission Unit Repair Section of the appropriate service manual for 3-4 clutch plate removal and installation information.

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.