Hi esteemed friends,
I have just replaced the gearbox output shaft oil seal behind the engine sprocket. I replaced the sprocket and lock washer. That went well. When I checked the alignment of the engine sprocket teeth and the clutch basket with a straight edge, as shown in the manual, I noticed that the back of the clutch spacer and shim would not sit against sprocket sleeve. There is a recess in the spacer which looks like it gives clearance for the circlip, but if I tightened the clutch nut to 70 foot pounds, it would be clamping up to a circlip , not the sprocket sleeve. It is difficult to explain . I hope the photos show my issue better.
70ft/lbs is way too high and…
70ft/lbs is way too high and risks destroying the circlip, ignore the manual and use 30 to 40 ft with locitie on the nut. There is also an alternative part that when thinned will replace the circlip and be stronger.
https://andover-norton.co.uk/en/shop-details/17464/circlip
So yes that circlip does take the strain.
- Log in to post comments
Circlip Chopping
As John says 70 ft/lbs is a bit too high and will probably shear the circlip. Don't forget there is a locking washer to sit behind the main shaft nut. This, some Threadlock, and not more than 50ft/lbs should do the trick. Sorry about the grotty photo.
- Log in to post comments
Input/output shafts.
Hi Nigel,
If you are not aware already, the clutch body can not bear against the gearbox sprocket shaft as this would lock up the gearbox and it would only operate in top gear. All the other gears will make the shafts turn at different speeds. Earlier gearboxes relied on the clutch body tightening up on the lead-out of the spline grooves, but being a wedge fit this could become jammed hard on the shaft and would need the extractor tool to remove it. Idealy, the body would be better butting on to a shoulder, but this would need a double diameter shaft which might then be too small. The circlip is the cheapest method of making a solid fixing.
- Log in to post comments
Machining the groove for the circlip
Has machining a groove for the circlip into old style mainshafts ever been a thing? I put a Commando mainshaft into my Dommie box many moons ago, and as I recall the only difference was this circlip groove. It was to allow a Tony Hayward belt drive conversion.
I want to fit a box with a reverse camplate before I change down into 2nd at 65mph again. Lucky to get away with a bent valve on that occasion.
Cheers
Steve M
- Log in to post comments
should read " output shaft oil seal behind Gearbox Drive sprocket."