AJS & Matchless Owners Club

Quick question before I finish with the gearbox.
When I was taking the sprocket off it took some time to get the sprocket nut off. How tight should it be when going back together?

I had to replace the sprocket on my recently acquired 18S. The nut was only finger tight when I took it off and it was only the very well used tab washer that stopped it coming undone completely. I did the nut up as tightly as I could using a tube/box spanner and an 18" 'tommy bar' before bending over the tab of a new tab washer. As the gearbox was on the bench at the time, I wrapped a length of chain around the sprocket and secured it to a length of 4" x 2" timber with long wood screws. That stopped it turning whilst I did the business with the spanner. I can't give you a torque figure but it was pretty tight and I don't expect it to come undone by it's self.

Thanks for that.
Did you notice any difference in how freely the sprocket turned when it was tightened up? When I tightened it up it wasn't turning as easily.

I can't honestly say that I noticed any great difference. It certainly wasn't tight enough to cause me any concern.

Right then, I'll do it up tight and if there is any cause for concern I'll just need to take it apart again .

Thanks for your help.

Have you also fitted a new oil seal just behind the gearbox sprocket? If so, then the sprocket will be slightly harder to turn when the retaining nut is tightened. Just behind the sprocket is the distance collar which is a good fit in the oil seal. When the sprocket is loose, the distance collar is free to float but when tightened up it is locked onto the sleeve gear and has to rotate within the oil seal, causing some drag.

Yep. There's a new oil seal.
If that explains the drag I'm a happy man!
Cheers Zwarts.

Don't forget to put some oil on the distance collar, where it fits into the oil seal.
They don't like being run dry!

Will do.