Spitfire spitfire transmission conversion to GT6?

[bob67bgt]

Hi, anyone know about putting a spitfire (OD) trans into a GT6? bell housing is different and the input shaft as well- can I just switch out these parts? Web site with this info out there? Need some help to get home this week. Thanks- Kevin

 

[Andrew Mace]

Unfortunately, it's not really practical. I sincerely doubt a Spitfire gearbox would hold up to the torque of the six, and the ratios -- especially 1st and 2nd -- are much too low (high numerically) for the six as well. All is not lost, as any functional Spitfire OD gearbox would be very easy to sell, but it's not going to work in the GT6.

What's the serial number on the gearbox?

 

[TR3driver]

More importantly, which overdrive? If it's a D-type, it shouldn't be too hard to source the parts needed to move it to the GT6 box. J-type I'm not so sure about, but it might be worth talking to ORS to see if it can be done:
https://www.overdrive-repairs.co.uk/

 

[mikecyc72usa]

For kicks we tried it about 15 years ago when I had 3 GT6s and a Spit OD trans lying around. After too much effort, the result we knew would happen did: trans disintegrated after about a week of driving. It was a fun "I bet we can fabricate what we need" project with several friends of mine who were very talented. It made it easier that they worked for various Indycar teams (I lived in Indianapolis at the time) and we had full run of the race shops after hours. I'd just source a GT6 OD transmission.

 

[vagt6]

I installed a J-type in my MKII GT6, it took a bit of fabrication and minor cutting of the propshaft tunnel, and new rear gearbox mounts since the J-type is longer.

Paul Tegler helped me install it, it's documented on his web site. The safron/yellow GT6 in the photos is my car.

https://www.teglerizer.com/triumphstuff/gt6/gt6jtype.htm

Not a project for the uninitiated, but it would have been easier if we had all the parts ready: we had to custom-fab the gearbox mounts out of angle iron, and then fabricate all the wiring. I got the gearbox from Quantumechanics, BTW.

If I had it to do over again I'd install the correct D-type overdrive. It's less expensive, mainly, and requires no cutting (although the J-type required very little cutting, actually). However, the J-type is a bit more robust. But for normal driving the D type is fine.

It's the most useful mod I did to this car, transfored her into a top-end screamer! Just loved that OD.

Let us know what you do . . . and good luck! :thumbsup:

 

[bob67bgt]

For now we just put a standard trans back in the car. The problem we ran into was the input shaft being way to short when using the GT6 bellhousing. Extending a pilot bush would have been easy but having enough splines for the clutch disc appeared to be a problem we did not want to deal with right now. We'll see if it ever makes it into the car. For now the car is back up and driving! Bob