so, i went to fit a new sprocket earlier. sprocket went on, then tab washer, then nut. i used rob's socket to tighten up the nut, at which point the sprocket seized up and i cant turn it by hand...
Is the bearing free and turning before you tighten the nut. If the bearing is seized the sleeve gear will still turn inside the bearing if the nut is left loose. Ron
I've got a 'box on the bench that has the same problem!! New bearings and the old sprocket turns OK but a new one tightens up when the nut is on. I still haven't found the answer but I think it may have to do with the radius between the sprocket face and the "spigot" part that goes over the shaft...probably wrong terminology but you get my drift?? This part of the sprocket seems to be contacting the casing when all is tightened up and the radius is the only identifiable difference in the dimensions between a sprocket that works and one that doesn't. Bloody annoying!
that sort of makes sense....the gerbox is completely reconditioned, and by Ian, so i trust everything is working as it should. so has anyone got a dimensioned drawing of a sprocket ? or, how far onto the shaft should the outer face of the sprocket sit ?
You will find that you have been sold a "modern" B series sprocket.
The latter sprockets for the boxes with an oil seal are a bit bigger in the flange so when tightened up fully will foul on the gear box case.
I have bought several lately that were supposed to be for WM20's but you can see where they have ground down the flange and one even did not have a scroll so it is off to Chain Sprockets P / L with the old ones for rebanding.
