After a lot of searching and reading and you fellows advice, I purchased a couple a radius arms off of eBay.  I still have not seen an exploded view of how they are attached, and I was surprised to find that they are just screwed in place.  Of course you all knew this!  I was expecting some kind of bushing, but now I see that they rotate on the threads.  So, when they ware, I'm guessing that the threads are what ware out?  I see on eBay a brake flange that the radius rod is threaded onto.  Which one wares?  Do they both have to be replaced?  There is not a lot of play at either end, but I would assume that there shouldn't be any.  Thoughts?

Thanks, Ken