GM TH400 Complete Racing Transmission – 1200HP – 2.48 Gear – SFI One Piece Case

For over 40 years Transmission Specialties has been the trusted name in the performance automatic transmission industry. TSI has pioneered much of the technology that is now commonplace in the transmission marketplace. The inventors of the spragless converter and the aftermarket Powerglide planetary, TSI is known worldwide for manufacturing and assembling the highest quality transmissions and components.

Unlike many production builders, our transmissions are handcrafted from beginning to end by one highly skilled and experienced technician. This process ensures that you the customer gets the highest quality product each and every time. This unit has undergone over 40 years of contiguous, rigorous R&D and on track testing.

Designed, Engineered and Assembled in the USA at our state-of-the-art Philadelphia, PA facility.

Disassembly Process and Cleaning

Complete disassembly of the entire transmission, all wearable “soft parts” are discarded.
Casing and housings are washed in our 190-degree hot wash tank.
Hard parts are thoroughly inspected and then either discarded or hand washed
Casing is thoroughly checked for any cracks or damage
Factory Casing is fully sand blasted
Upgrade Internal Components

TSI SFI Two Piece Cast Aluminum Case or OEM Inspected Case
Choice of Stock or Billet 300M, Aermet Input Shaft
Choice of Stock or Billet 300M, Aermet Main Shaft
Choice of Stock or Billet 300M, Output Shaft
Choice of Stock or Billet Steel, Aluminum Direct Drum
Choice of 34 or 36 Element Intermediate Sprag
Choice of Stock or Billet Reverse Manual Valve Body
Two or Three Speed Option
3/4/5 Intermediate Clutch Option
Rollerized or Bushing Tail Housing
All new bearings
All new bushings
Alto Red Eagle Clutches
OEM or Aftermarket Pump
All New External Fasteners
Deep Aluminum Pan w Drain Plug
All New Gaskets and Seals
Endplay and Clearances Set to Exacting TSI Performance Specifications