743 rear sprocket drive

[Zappo]

I lost the drive to one of my rear wheels. Opened it all up expecting to find a broken chain. Nope , the sprocket had sheared off the axle coupling. Everything else looks OK and it didn't do any other damage. Strange thing is it looks like the weld on one side has been ground down? Priced a new sprocket at $420. Questions are; Can the sprocket be welded back on to the coupler with an outcome of reasonable durability for a machine that only sees occasional use? Does the axle have to pulled partialy out to reinstall the sprocket? Was able to drive a pin out of the chain to seperate it and wondered if the old pin could be reused and just hammered over with a ball peen and a heavy backer to resecure the chain link. The book says to tighten axle bolt to 425 ft lbs, can that be right? Is a 6 piont 1&1/8 box end needed to remove the axle bolt or will a 12 piont do? Any experience in this area would be welcome info.

 

[Tazza]

Ok, the sprocket can be re-welded. One side is ground as its machined to a set thickness to put the correct amount of load on the bearings. When its all bolted up, it plls the bearings in and seats them, so this width must be correct, or very close. You can fine tune it with the washer that the bolt goes through to attach to the axle. I would remove a link in the chain and install a master link, i wouldn't trust knocking the pin back in, but this is your call. The tension is rite, if you don't have a torque multiplier, just pit loctite on the threads (when you have the washer rite to adjust it so there is NO end float on the axle) and tighten it up as much as you can.
Hopefully that answered what you needed to know. I see no reason why it wouldn't work, especially if its not used all the time.