Triumph Repair: transmission substitutes, re: 1966 to 1980, overdrive transmissions, speed gearbox

Question
Jim:

Good Morning.  I have a 1966 Triumph Spitfire 4, MK II, that has a 4 speed manual transmission.  Is there a way that I can either get the 5 speed that originally came with my car (opt), or select another Spitfire year 5 speed transmission that will bolt right up?  If so, which years can I pull from?  I love my spit, but would love it that much more if i only had a 5th gear!  Harrison, TN.

Regards,
John

Answer
John,

I suspect that you're thinking of the overdrive transmissions fitted to the Spitfires, there was never a 5 speed gearbox in the Spitfire.

If your car still has it's original engine/transmission then you have a three rail three synchro transmission with small output flange.  The easiest way to tell is to remove the transmission tunnel and look at the serial number stamped into the top of the gearbox casing.  If your transmission is original it should be an FC or FD prefix to the serial number.

This basic transmission was used in the 1962 thru 1970 Spitfires.  In 1971 the Spitfire recieved a transmission with a synchro on 1st gear.  This transmission has an FH prefix.

This transmission was used through the 1974 year.  For 1975 thru 1980 the Spitfire was fitted with a single rail gearbox.  That transmission should have an FM prefix.

Having said all that, with the right perserverance you can fit any year overdrive gearbox into any year Spitfire, although it will be easier if you stick to looking for a '62 thru '70 D-type overdrive.

You need to make sure you get the shift lever, driveshaft and trans mounting plate for the overdrive as they are different than on the non overdrive cars.


There are companies making an adapter kit to fit some of the more common Japanese 5 speeds into the Spitfire.  I have no experience with any of them so I have no recommendations if you choose to go that route.


Cheers,

Jim