gearbox help
Turbo Mini Forums

hi lads is it posibble to fit a pre a+ gearbox onto my metro turbo what do i have to change if anything cheers

Why would you want to do this? You can do it, yes, but the drop gears have a smaller shaft and are not as strong. Also the gear tooth form on the A+ box is different (and I believe stronger) than the A box.
All in all not really worth doing IMO?

The A+ is NOT stronger than the A. The only rason they went for the A+ angles were to reduce noise.
Also, the 3rd shaft(mainshaft) is 18mm instead of14mm on the A ones, but they are made of a far softer material.

Also, the A idler has got a longer shaft which possibly is better for twist? Although the bearing it self is stronger/larger on the A+.

If the mainshaft is shagged, a new A+ one £240 whereas an A is £70.

Finally, the ratios on the A+ engines are even worse than standard A.

A+ is A- in my book :)

Edited by Vegard on 4th May, 2005.

Conficting opinions!!!

Can't offer any reasoning for the change in form between the A and A+ other than the AR engineers must've had a reason to change it with the impending introduction of the 998 and 1275A+ engines...

So - if you wanted to use an 'A' in your metroturbo engine - what do you need Vegard? I'm guessing the transfer case off the 'A' needs to be used - what about the transfer gears? Does a 'big bore' pre A+ primary have to be used?

ok so am i guessing this is a pre a+ box

All A rod internals fit easily into an A+ housing. You can fit the A dropgears in an A+ box as well, as Minispares sell a special bearing.

Remember that the reason for increasing diameters on the A+ box was NOT to make it stronger. It was to save money, as they've used cheaper materials. Look at A+ rods.. Worse material, but still up to the job.

The only snag, is that you cannot fit an A+ layshaft in an A+ box. The step on it, is machined 1mm too far out... Easily machinable, but not plug and play.