For 1990-2009 cars

All automatic transmissions have a metal identification (ID) nameplate (1) attached to the case exterior.

(1) | Transaxle
(1) | Transaxle
(2) | Calendar Year
(2) | Calendar Year
(3) | Julian Date or Day of the Year
(3) | Julian Date or Day of the Year
(4) | Shift and Line Number
(5) | Model Year
(5) | Model Year
(6) | Model
(6) | Model
(7) | Part Number
(8) | Serial Number in Base Code 34
(9) | Plant
(10) | Broadcast Code
(11) | Control Number
(12) | Serial Number

The Hydra-Matic® 4T40-E transmission has a metal identification nameplate (1) attached to the case exterior.

The information on the nameplate assists the technician in servicing the transmission and ordering replacement parts from a GM Parts Catalog.

Additional transmission identification information is provided on the Service Parts Identification label. This label shows the regular production options (RPO) as well as the standard and mandatory options. This label is affixed to the inside of each vehicle at the assembly plant.