GM Transmission Code Sample

The GM transmission name is arranged in in connection to the number of speeds, configuration, relative torque capacity and type or features.

For example if the first number is a 3 than you have a 3 speed transmission.

The letter following the the number of speed indicates if the transmission is longitudinal or transverse. Longitudinal transmission are usually associated with rear wheel drive (rwd) units and transverse transmissions are usually associated with front wheel drive (fwd) units. A 4L80E is a rwd and a 4T80E is a fwd.

The set of numbers following the letter indicating if the unit is rwd or fwd is the relative torque capacity. The relative torque capacity for the 5L40E is 40 and for the 5L50E is 50.

If a letter follows the the relative torque capacity it will indicate something additional. For example the 4L60E is electronically controlled, whereas the 4L60, previously known as the 700-R4, is not electronically controlled.