Ariel Owners Motorcycle Club

Hey guys,

Just a question with regards to main shafts. I’ve stripped down the engine I obtained and whilst inspecting things found the drive side main shaft to have excessive wear in the area that the bearings are situated. Bearings should be a firm push/lite tap fit however they just fall on/off the shaft, Timing side are not quiet as bad but could be better.

I can obtain another set of good shafts, other than ensuring they are installed and aligned to the flywheels correctly using a dial indicator is there anything else I need to look out for. Would it be worth lapping the tapers of the new shafts into the existing flywheels using some fine grinding paste?

Cheers

Josh

I wouldn't expect there to be any issues with the tapers in the flywheels but I'd make sure
that those on the replacement shafts are in good condition. If there are any issues I'd
avoid any grinding in the flywheels - you can't put the metal back later.

Do make sure you have the correct mainshafts as there are at least two different lengths
of drive side shaft and three versions of gear side shaft , two of which are identical
except for the position of the oil hole.

Will,

Was aware of the differences in shafts and can confirm they are the same. So no lapping of the tapers, just a good clean, install and align.

Cheers

Josh

Successive nut tightening can raise a Burr there that makes the taper fit appear bad. Check and judiciously use a scraper to remove it evenly. Lapping is not recommended as the Hard shaft is more likely to be altered than the softer wheels as the abrasive embeds in the softer metal. Nev..

Josh I must say that I never owned a Ariel on which the mainshafts did have a very tight fit or required a tap to fit in the bearings. Howmuch play do you measure? Most, if not all, shafts do have that ‘mirror’ looking surface on place of the bearing. Yes the shaft may do some creeping in the inner race, but not much I guess. It is kept in place, very tight, on the inner race because of a serious amount of pressure of the spring.

Cheers for the reply’s guys, appreciated.

Paul, the shafts have lost their “brightness” and are pitted. There is no interference what so over between the bearings and the shaft and the bearings spin on the shaft when turning them by hand. Maybe the tension on the spring may hold it in place however I’ll sleep much better at night knowing the bearings are a little firmer on the shaft then what they currently are.

Pic of each of the shafts below, can see the pitting in both shafts, the worst of it is on the drive side shaft and is pitted in multiple spots around the shaft.
The timing side bearing fit is a little better and could be usable if needed but will aim to replace that also.

Hello Josh, the photographs makes things more clearly. Succes!