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Triumph Spitfire - over drive in a 74 spitfire

has any one refitted a 74 with an overdrive trany? how was it? what did you use. I am looking for any info out ther
DE Eastland

I can't help you too much DE. I have never done it but if you can give a little more information perhaps I can offer some suggestions.

My 68 Spitfire has no OD. My 69 TR6 does.

Are you replacing the whole transmssion with an OD mated to it or just retrofitting an OD?

Is the overdrive an original or are you refitting a different make?

There should be no problems if you are replacing with an orginal make. If you are installing a different make, you may have support attachment location adjustments to make or perhaps adaptors for the flanges.

Any additional information would help.

You might want to post on the GT6 site or Tr6 site. GT6 are very similar and the TR6 site is referenced by a lots of people with lots of Triumph experience.

Mike Petryschuk
Michael S. Petryschuk

I am looking at two ideas

1 drop a Triumph od tranny, it seems the most simple but I wounder how much is involved. outher then the tranny what outher components will I need out side of the gear box? I like keeping every thing TR but is my money better spent

2 a ford 5 speed kit coast is $700 more then a TR od tranny, but it is all thear no extra componets to run down.

do you have experience or advice on witch is going to be easer better. again I just want a cruising gear so I can keep the rpms down. I have a 1500 turning around 100 hp.
DE Eastland

If the spifire is mostly like the tr overdrive, you will need an overdrive mainshaft and an adapter plate, as well as a usable OD unit.

I assume here that you would be re-using your existing tranny. You rebuild it using the OD mainshaft, bolt on the adapter plate, and slip on the OD unit.

If you are going to replace your tranny with one that already has an OD box, all you have to do is wire in the dashboard switch.
Al Christopher
A. R. Christopher

I would think it easier to just put in the SPitfire OD. There will be a lot less modification than a Ford transmission. But then I know nothing about this Ford kit you reference.

Sorry. I guess I need pictures or schematics to make any other comment.
Michael S. Petryschuk

If you decide to go with the Spitfire O/D you will also need to use the O/D drive shaft and an O/D rear mounting bracket which are different then the non overdrive driveshaft and mounting bracket. The rear mounting bracket is still available at Moss Motors, The Roadster Factory and Victoria British. As for the driveshaft I'm not sure about availability on this unit.I looked into the Ford 5 speed and it is quite expensive, but more reliable since you don't have to worry about any electrical connections.
Abel Miramon

I installed the Hi-Gear engineering (UK) 5 speed gearbox conversion kit with the Ford Type N gearbox in my 1973 MGB a few years ago. It was a very well engineered conversion and was truly bolt on - no metal bashing or modifications required to fit. Driving experience was excellent and I put on 10000+ miles before selling it to buy my current TR6. Having since experienced an OD in the TR6, I must also say that it is very nice to drive in third gear switching in and out of OD when in town or out in the country on twisty roads.


BJ Quartermaine

This thread was discussed between 19/02/2007 and 09/07/2007

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