It looks like the bearing was staying on the shaft. The idler was sliding off. The shaft is not adjusted parallel. sighting from the back, the idler did not line up with the spacing in the road wheels. It's better now. I will try to make sure it rides well when I put the tracks back on.
Patchcon... I found the right links for the drive chain, at Menards. I think I'll leave mine as they are, and keep an eye on them.
