The transmission model identification is located on a label or tag on the transmission case. If this label is missing or unreadable, use the service parts identification label in order to identify the vehicle's transmission.
Fig. 1999 4L60-E Transmission - (1) Model Year (9 = 1999) (2) Model (3) Julian Date (5) Shift Built (A, B, J = First Shift; C, H, W = Second Shift) (6) Serial Number (7) Transmission I.D. Location (8) Optional Transmission I.D. Location
Fig. 1999 4L80-E Transmission - (1) Model Year (99 = 1999) (2) Calendar Year (3) Julian Date (4) Hydra-Matic 4L80-E (5) Model (6) Transmission I.D. Tag Location
Fig. 2000 4L60-E Identification tag location
Fig. 2000 4L80-E Identification tag location
Fig. 2001-04 4L60-E transmission ID and VIN derivative location (1)
Fig. 2001-04 4L80-E 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 derivative.