Automatic Transmission

The Chevrolet TH400 is a renowned three-speed automatic transmission, celebrated for its durability and legendary status in the automotive world. Originally introduced by General Motors, it has found its way into a wide array of vehicles, including GM cars, Jeeps, Jaguars, and even Ferraris. The TH400 is characterized by its robust construction, featuring a cast aluminum alloy case, aluminum forward and direct drums, and intermediate and input shafts made from aerospace materials. Its standard gear ratio is 2.48 for first gear, with reverse at 2.08:1 and third gear at a 1:1 ratio. Jake's Performance offers various builds of the TH400, catering to different power levels and applications. Their Stage I build is designed for up to 450 HP/TQ, featuring hydraulic and lubrication upgrades for increased service life. Higher stages, such as Stage 3 and Stage 4, are engineered for 1000+ HP and up to 1800 HP respectively, incorporating billet input shafts, forward hubs, and stronger intermediate shafts. For extreme applications, the TH400 X-2 and Ultra 400 models offer enhanced features like billet transbrake valve bodies and lightweight designs for maximum efficiency and drag racing performance. Off-road and rockcrawler specific TH400s are also available, utilizing heavy-duty cases and reverse manual valve bodies for engine braking. The Maximum Effort Offroad TH400 uses a new Reid Racing case for ultimate durability and incorporates a spragless design for 2nd gear, providing exceptional engine braking. These specialized builds often include 300M input shafts, alloy intermediate shafts, and robust lubrication improvements to withstand harsh off-road conditions.