Catalyst Powertrain Complete Service for Your Allison / Twin Disc TT & TRT Series Transmission
Catalyst Powertrain is an Allison Transmission authorized service center. We provide reman units, parts, repair, installation, and maintenance for Allison Transmissions.


About the Allison Transmission TT & TRT Series
Allison TT (Twin Turbine) Series transmission consists of a 4 element converter that transmits power from the engine to the transmission gearing through two sets of turbine gears. When torque is in high demand, the freewheel clutch is engaged and the first turbine, assisted by the second turbine, drives the range gears. Once vehicle speed increases and torque demand decreases sufficiently, the second turbine assumes the entire load and the freewheel clutches disengages. This transition from high torque to high speed is automatic. The most common applications for TT/TRT series transmissions are Front End Wheel Loaders, Deck Winches, Cranes, Material Handling Equipment, Compactors, Tractor Pulls, and Skidders.
Features of the Allison TT/TRT Series Transmission
- TT Series = 2 forward ranges, 1 reverse range
TRT Series= 2 forward ranges, 2 reverse ranges
Internal Brake option
Inching, Air or hydraulic controls
Multiple converter series and ratios
Long Drop or Short Drop
Remote or direct engine mount
Converter Driven PTO
Output Driven PTO
