Modding the floating primary gear bush
Turbo Mini Forums

I changed my inner idler bush approx 600miles ago and used one of the floating ones but it has siezed onto the crank now.

Looking at the old posts I see there is a mod that needs doing to use it with the turbo crank,but can't find out what it is ?

I also put it in with the chamfer inward is this correct


Would it be a good/bad idea to try fitting needle roller bearings in instead

Metro turbo weekend driver,Mini turbo in the making again!

Any ideas on these,Mine don't last very long.
Another 2 on order :(

Metro turbo weekend driver,Mini turbo in the making again!

just saw your post over on mf dude.

I got one from morspeed the other day and i remember there being something that needed doing to fit the turbo crank. We had a look at it and machined a chamfer in the end of it and it looks to be ok now but only time will tell i suppose.

i did a search on here the other day cos i remember fast carl posting something about it before, i'll go find the post again.

Edited by Nick on 21st Dec, 2006.

As with anything - if you just bang it on without inspection, at some point, quality control will bit you in the arse...

Sermon over - You need to get the bush in a lathe. flash one end off so it is square edged. The edge between the end face and outer surface can be left square.
The edge between the inner bore and end face needs chamfering (simple 45-degree chamfer).
How big of a chamfer, i don't exactly recall - but make it such that you have around 0.2-0.3mm of end-face remaining, and that will suffice.

Now, take the bush, fit it to the crank with the chamgered end inwards, and try twisting it whilst pushing it on.

It should not lock up - if it does, remove it and open the chamfer up a fraction more. Basically - you need a 'flat surface' on the end to act as a thrust face - if it's left sharp it'll burr over and jam once again.

Hope that makes sense.

Now thats odd,
First) The 2 that I ordered from minispares yesterday got here this morning.

Second) The ones I have now have a chamfer on both ends,where the previous one's have only had a chamfer on one end.

Third) They have a different chamfer each end,when Its on the furthest it stops short of the radius on the other side by approx .040"

Tryed on a spare turbo crank and seem to fit ok

Edited by Dangerous on 22nd Dec, 2006.

Metro turbo weekend driver,Mini turbo in the making again!