drop gears noise
Turbo Mini Forums

Hi everyone,

I have a problem with my mini turbo. It makes noise when idling in place when clutch is relesed. The noise is coming from drop gears (helical ones). When clutch is presed noise stops. I have change all of the roller bearings in the gearbox, including idler gear ones, first motion ball bearing and laygear shaft yesterday. The clearances on laygear, idler gear, and primary gear are set to the haynes manal, and it still makes nose. What am I mising.
I have turbo phase III cam from avonbar, and it is lumpi at idle...could that be a reson for that noise, since with std cam I could bearly hear any noise?

PLEASE HELP!

Tonci
regards,
Tonci

Could it be your clutch release bearings?

Sounds like typical drop gears to me. I usually set the idler gear and primary clearance as tight as possible (factory minimum clearance) and this makes them silent. They will be noisy if the clearance is close to factory upper limit.

You might try to increase the idle a bit. Rough running cams and idle revs too low makes the enginerun bad and it will also effect the drop gears. Higher idle revs will only be a short term solution, check and adjust the drop gear clearances again.

Jukka

I think that the problem is in radial play on primary gear. It has at least 0.5 mm of play so it defenetly needs new bushes. What do you think about floating front bush?

0.5mm radial is quite a lot!!!

I use the fully floating bush, having suffered too many failures of the standard bush seizing onto the crank. Since fitting, i've not had a single problem.

Dave

Well that explains the noise. There is no point in fitting one with that kind of play. It only wears the axial thrusts within a few hundred kms if even less ! With bad luck you?ll end up looking for another crank...

Jukka

Yes I know that there is no point in fiting one with that kind of play, but I thougt...maybe it will be OK... I , my mistake. I know that on this kind of engine helical drop gears (their bearings, maybe better to tell) are overstresed and have short life when fitted new, not to thell what would happen with this one if I have drove the car with them. Since I live in Croatia it is rather hard to get any part for mini. I allready have new rear hat type bush but I don't have front one. Regarding all that I have decided to fabricate my own floating front bush (from phosphorus bronce). What should I keep in mind, does it need to have cut (like the one on minispares site) or it can be all in one piece like ring? Any help welcome...

regards,
Tonci

All floating bushes that I have seen so far (not Mini primary gear but in general) are one piece, not split. I don?t know how the Minispares item looks like but it would sound logical that it is one piece. Dave ???

I agree with you Jukka, but I like to ask before doing semething like that, just to be shore...

Tonci