Converting a 1979-1993 Fox Body Mustang to a TREMEC TKX 5-Speed Transmission
The TREMEC TKX 5-speed has opened up a whole new world of driving enjoyment for classic and late-model cars and trucks. But many people wonder what is really involved in converting an automatic-equipped car to a TREMEC t-speed. We recently followed along with Knights Automotive in Oveido, Florida, as they made that conversion on a Fox Body Mustang.
The compact transmission case design of the TREMEC TKX allows for fitment in vehicles where a modern 6-speed manual transmission might not fit without major transmission tunnel modifications. The high torque handling capacity, high-rpm shifting ability and available gear ratios make it ideal to put behind almost any engine.
The 1979-1993 Ford Mustang is one of the most popular cars for car enthusiasts. They’ve proven to be highly adaptable for building in a variety of ways, from street performance to race cars. Ford built more than 2.5 million Fox Bodies, assuring there is still a plentiful supply of these Mustangs. But the majority of 1979-1993 Mustangs built were automatics, making factory manual transmission-equipped Fox Bodies more difficult to find. But converting an automatic-equipped Fox Mustang to a manual transmission is an easy, straightforward process.
Thanks to the design of the TKX, it easily fits in a Fox Mustang transmission tunnel without any modifications. The TKX actually takes up less space than the factory AOD automatic, and it weighs almost 200 pounds less than the AOD with torque converter. Capable of handling 600 lb-ft of torque, the TKX can easily handle a pushrod V8 or one of the modern modular or Coyote Ford OHC V8s. You can find all the details and specs on the TKX in our previous blog.
To show how easy converting a factory automatic Fox Mustang is, we found a suitable AOD-equipped test subject for the demonstration. This particular car is a factory SSP (Special Service Production) which were typically used as pursuit vehicles for state police, sheriffs and highway patrol units where a lighter, speedier and more nimble vehicle was needed over the typical police sedan.