5 replies to this topic

[E-Tizzle]

this is a purely hypothetical question, but i thought i would throw it out there and see what you guys think.

what do you think is the chances of transplanting an overdrive system onto the gearbox. im no expert but im think im right in saying the overdrive is bolted on after the gearbox and is not actually inside of it. do you think this is possible.

or is the only way to put a whole new engine and gearbox in there, for example a mg engine complete with overdrive.

im not going to do this is just wanted to know, and know what you guys think.
i think most of what i said is correct (ish) but if its not dont shout at me.

comments... (pictures)

[njathind]

That is an awesome Idea, screw my plans for an expensive 5 speed gearbox. I didn't think about an overdrive, I once tested a triumph spitfire with overdrive (I was gonna buy one then I got infected with the incurable mini bug) and you would not believe the difference it made, if you know how to use it it would be like a 6 speed gearbox....ish

If anyones done it let me know how as I want one, I might just nick a unit off a 1.3 spitfire.

[Cooperman]

You need a single output shaft (prop shaft) to fit an overdrive so it's really a non-starter in a Mini. It has to go between gearbox output and diff input.
Interestingly, overdrives could be wired to operate on all gears (but not reverse!!!), although on 1st they used to break. On some 60's rally cars, like the Sunbeam Rapier, they used to wire them on 2nd, 3rd and 4th, thus giving 7 forward gears. It was great on short straights when you would come out of a corner in 2nd, need a higher gear half way down a short straight, flick into overdrive 2nd, then back into direct second for the next corner.
Showing my age now

[E-Tizzle]

yeah i did think about the single output shaft thing, i know they are fitted to mgs which are rear wheel drive. and also not a transverse engine. hence, not having to split the drive inside the engine bay.

looks like njathind your gonna have to buy a new engine and convert you mini to rear wheel drive if you really want an overdrive. good luck!!!

other opinions still welcome

[Ethel]

Since we're being hypothetic: an auto gearbox is just a collection of overdrives and there's one of those that works in a Mini sump. Wonder if there's enough room to squeeze an epicyclic hub on the end of the 3rd motion shaft & link it a final drive pinion?

[njathind]

yeah i did think about the single output shaft thing, i know they are fitted to mgs which are rear wheel drive. and also not a transverse engine. hence, not having to split the drive inside the engine bay.

looks like njathind your gonna have to buy a new engine and convert you mini to rear wheel drive if you really want an overdrive. good luck!!!

other opinions still welcome

Damn it, my mpi's gearbox is running fine on it at the momment so I can't really justify a new box when the current one works fine, the gearbox is about the only thing that works properly on the car.