fitting an overdrive to a 4 speed manual

[readie]

does anyone know if you can retro-fit an overdrive gear to a 4 speed manual ?

I do not really want to change the whole gearbox and am having it reconditioned and I have had some other cars which had an overdrive switch fitted to 3 and 4th gears and wondered if it was possible to do this on a 72 coupe ?

 

[adawil2002]

Haven't heard of that being done. You are talking about changing the gearing in the transmission?

 

[teahead]

Ya, with great expense. Gear Vendors can do this I think. But at $3k plus install, not worth it.

Just get a Getrag 265 5-speed. Why waste money getting a 4-speed redone?

 

[MMercury]

does anyone know if you can retro-fit an overdrive gear to a 4 speed manual ?

I do not really want to change the whole gearbox and am having it reconditioned and I have had some other cars which had an overdrive switch fitted to 3 and 4th gears and wondered if it was possible to do this on a 72 coupe ?

With 5-speed overdrive transmissions available, me thinks you are reinventing the wheel when trying to fit the 4-speed with an extra gear (or two). That said, external overdrives have been fitted to many cars, including the venerable Ford Model A and you could likewise conceivably adapt a Layc_ock overdrive found on Volvos and various British marques to your setup. Mind you, it would most probably involve additional weight and some drive shaft modification, reorientation of the shift lever, minor electrical work and some reshaping of the body's transmission tunnel, but other than that, some might call it a simple "bolt in." :shock::shock::|

If you feel like taking on the problem from the other direction, you could always add a second speed to the rear axle.:idea:




Cutaway of trans mated to Layc_ock overdrive.

 

[readie]

thanks guys