Morris Minor Owners Club

I don't think any A series engines uses overdrive but marinas had triumph derived gearboxes that used overdrives when in triumphs, so it may be possible to build something up that will bolt to the engine using off the shelf parts, your next problem will be the marina gearbox doesen't really fit inbetween a minor chassis legs, though I think there was some sort of conversion backplate at one time, finally you would amost certainly have to cut some of the floor and trans tunnel away, thats if it all even fits in front of the centre crossmember.

So my conclusion is it might just be possible but would involve a hell of a lot of work and compromises a 5 speed kit would be a lot easier.


Happy to be corrected etc.

This subject is covered I the Morris Minor modification manual by Owen Burton . I think I got my copy from ESM. Short answer is possible but difficult, i.e.. certainly beyond me! Although he doesn't mention any need to modify the floor
Cheers JohnG

As others have said. Anything is possible. As I'm sure you know, overdrive was an option on the Triumph Herald/Vitesse/Spitfire as well as the MGB. Some have fitted the MGB engine and gearbox to Minors and I have had a Minor with the Spitfire 1500 engine and gearbox (heck of a lot of work and you end up with an engine certainly no better than an "A series"!). I can't think of any other route. Both these options give you a larger and heavier gearbox and a great deal of work and, in my opinion and having tried all sorts of things over the years, the best thing to do with a Morris Minor is to keep it simple and sort the gearing out that suits you best by fitting the most suitable final drive and sticking to a 4 speed gearbox.

The tail housing is so long and could easily include an overdrive. If one is up to some fabrication work, you could modify the third motion shaft to have third and input wheels and then a laygear but have them reversed so that the third motion shaft drives a fourth motion laygear using the third gear set and the input gear set drives a fifth motion shaft which has the speedo drive.

I think that an overdrive unit mounted on the rear axle is easiest for the Minor....a 5 speed box will be much easier though


Taupe

Marina/ ital box internals in a triumph housing with overdrive attached, engine backplate as per marina gearbox conversion and it all bolts up and works.

Triumph gears are all the wrong spacing for the minor, hence the case swap.

Interesting bit of 1950s motoring history:
By 1957 the Minor's direct competitors, the Standard 8 and the Standard 10 were listed with optional Laycock overdrive.

I fitted one to my MG Midget 1500, which of course uses a Triumph engine. In my case, the gearboxes were the same, aside from the obvious and slight differences with the selector rods. My old bell housing fitted (Unlike the A Series box, the bell housing is removable). The standard, single rail box is described as Marinalike and of course the Marina also used the A Series, albeit in a different form. I have read the Owen Burton thing and I seem to recall that the innards have to be swapped around a bit and that you need a Marina back plate. The starter motor is on the other side, with the 1500 but I'm not sure about the Marina. I think the steering rack could be an issue.

I have a Ford box in my Morris and of the two, I think the Triumph box is the more positive and the nicer to use. The gap, between 2nd and 3rd, is wider than on the 1275 Midget but the 1500 has more torque, so it doesn't matter so much (I imagine the Marina 1300 wouldn't wear it so well and I expect the ratios are different. The 1275 Midget box is similar to the late Minor box. It's very positive and lighter feeling, than the 1500 box but I fancy the 1500 box may be the stronger (I know it's not dissimilar to the GT6 box).

I've done more than enough car jobs (And others) over the years and still have a number of long term projects to finish, so I don't want to take on anything else. However, if anyone is brave enough or rather has the time, I reckon a Triumph 1500 TC, with the overdrive box, would make a nice combination. The engine is a tad longer than the 1275 and a tad heavier (But not in the league of the MGB engine, which I know has been done), so it wouldn't be a simple swap of one small engine for another.