How bad is it worn? I repaired one during wheat harvest two years ago. We couldn't find a tube that was the right size so we had the machine shop bend a piece of flat metal into a tube, slid it into the old one, welded it in several spots and kept on running, then we fixed it over the winter.
It will take awhile to fix. As I remember you will have to take the chain sprocket off, slide the top auger in toward the rotor, unbolt the tube where its is bolted to the side of the combine and from the return. I would put all new bearings in while I had it apart and then reverse the process. I don't remember if we had to move the return elevator or not????? I think we did though so we could get the old tube out and put the new one in.
ya ours is junk we have been putting duct tape on it for quite a long time now which our outter hub is getting worn so we were going to replace it we figured while we were doing that we might try to hack into replacing the tube