Chevy's Turbo Hydramatic 400 (TH400) transmission is one of those legendary pieces of equipment that helped to define the muscle-car generation, and it continues to be one of the most common and highly regarded transmissions in today's enthusiast market.
The TH400 (then called the Super Turbine 400) was originally introduced in 1954 for use in full-sized Cadillacs and Buicks. The design remained almost completely unchanged from its inception to 1991, but it was renamed 3L80 in 1987.
The TH400 is a GM three-speed automatic transmission, used in high-performance and high-torque applications.
You can differentiate the Chevy TH400 from the Buick-Olds-Pontiac transmissions by its specific bell-housing bolt pattern and the fact that it only came with 4-inch/small-yoke or 9-inch/large yoke tail-shafts.
The TH400 has also seen use as factory equipment in military vehicles, full-sized Jeeps, Ferraris and V-12 Jaguars.
The TH400 was replaced by an overdrive evolution of itself in 1991, called the 4L80E.
