GM Service Manual Online
For 1990-2009 cars only

A Transmission ID Tag and a VIN Dervivative stamp is located on the transmission case.

4L60-E Automatic Transmission


Object Number: 661681  Size: SH

The 4L60-E transmission ID and VIN derivative location (1).

4L80-E Automatic Transmission


Object Number: 661676  Size: SH

Transmission ID and VIN derivative locations (1,2). The right hand stamping is shown, left hand is opposite. Pin or hand stamp location (3) for the transmission ID or VIN dervivative.