Borg Warner T5 Conversions for a Triumph TR4-TR6

Geoff DuPont developed a T5 conversion kit for Triumphs in the late 2000’s, his kit was ready for the market around 2009, and by 2014, he was done. I have no idea how many kits he sold, but I have two kits for sale. Thanks to the Wayback Machine, his website is preserved.

Dupont Machining.com – T5 to Triumph TR6 Conversions

There are a few 5 speed conversions available for the big chassis TR, so why go the T5 route? First of all, the T5 is legendary on the hot rod and racing world. It can take hamfisted shifting better than the alternatives, and was installed in many, many vehicles so finding a gear ratio you like is not too difficult. The Toyota Supra gearboxes that you want for the HVDA conversion are getting very scarce, and parts availability is questionable. The kits are no longer available from Moss, they have jumped ship to a Miata-based conversion, they call it the Vitesse gearbox. As of this writing, Moss is showing the Vitesse conversion is available for $6938.

The first one was in a TR6 I purchased from a club member. He installed the gearbox and proceeded to put at least 50,000 miles on the car, driving it to national shows for several years. He moved on to other things and I bought the car to fixing it up and flip it. One of the things I did was replace the gearbox with a stock TR6 box with overdrive, so the T5 sat on my shop floor for a bit. I then rebuilt the T5 with a close ratio racing gearset and tryed it in my racecar. It didn’t perform as I hoped, so the racing T5 gearbox was sold to a Mustang racer. Obviously, he didn’t need the custom Triumph bits, they are what I am selling. The kit is complete less a T5, easily obtained on Facebook Marketplace. It is the bellhousing made to bolt up to the back of a TR2-6 engine and a Borg Warner T5. The tailshaft housing was modified to move the shifter back to the correct location for the TR. The output shaft is included, as the bushing in the tailshaft housing is honed to fit the output shaft. The output shaft was modified to accept the TR u-joint flange. The shifter is included, as well as a driveshaft. This setup uses a stock TR4A-6 pressure plate, a custom clutch disc, and stock clutch hydraulics.

The second one I have was never installed on a car. It was purchased by the guy who bought the T5 racing gearbox from me, but he never got around to doing anything with it. This kit includes a rebuilt T5 gearbox, the conversion bellhousing, the conversion tailshaft housing, shifter, and uses a hydraulic throwout bearing setup. It does not have the output shaft, that got lost. I have a driveshaft that may work for you depending on what differentail you are using.