MiniSpares 5 speed box

OT posts from this thread.

5 Speed Gearbox

Made by MiniSpares

Upgraded to evolution spec by MiniSpares North approx 20k ago

In excellent condition, used on my own Mini Cooper.

Helical cut gears, central oil pickup, 3.44:1 final drive, rod change

Is this the type that 5th is like an overdrive gear? If so dont some people question the bearings and the way the overdrive is mounted?

If its MiniSpares then ues, 5th is like an overdrive. I believe its only the Jack Knight box that puts all 5 gears into the same space as the usual 4.

when i looked into buying mine both minisport and minispares said buy the jack knight box

i dont know why

So in the photo, which bits the overdrive?

Hmmm, just an educated guess. I don't think the 5th is exactly like the overdrive found in other cars. But I would say its the gears found right next to the speedo housing (left side of the above pic). With a 4 speed box theres no gears on that side of the box.

I'm going to split this topic since we have seemed to have hijacked EP90s thread! Sowwie!

5th speed is an overdrive in all 5 speed boxes except for the KAD racing only box. This is also the only box which fits all the gears into the standard gearcase.
All that being an overdrive means is that it drives the FD pinion faster than the input shaft is turning, it's just that this has certain associated inefficiencies which means that gearbox losses will be higher in 5th than in top.
These boxes have a limit on their ability to cope with torque due to the relatively small bearings. 85 Lbft is meant to be the maximum I think but they have been successfully used on meatier engines than that.

I don't think there's a problem with the mounting of the overdrive gear as such, I believe there may have been a problem with the drive to the overdrive laygear in earlier Mini Spares boxes but this should corrected in the Evolution spec.

It's not like a seperate overdrive unit which you switch in and out, it's just that 5th gear is an overdrive ratio.

Edited by Dan, 29 April 2006 - 05:14 PM.

I have run this gearbox on my 80lb/ft Mpi engine before and after the upgrade with no probs. Minispares use the evolution box on their 1380 8port with no probs (I've not got any torque figures for this engine though)