banshee

I have a 46" Husky riding mower and the front wheels keep wearing out the shafts they ride on. I replaced them with all the parts listed in the manual, but it seems I'm missing something. The wheels are real wobly. It looks to me like there should be a sleeve of some sort between the the shaft and the hollow part of the rim. Nothing like that is mentioned in the part book. I'm assuming there must be something there, or it was part of the rim and just wore out.

Any ideas?

Thanks in advance.