thanks. I will try all three things.

I have suspected the brake caliper from the start. I had to replace it, the slide bolt had broken inside the old one. So I have checked that frequently, it does not appear to be loose in any way, nor is it warm to the touch after extended riding. It is something I still suspect mainly because I'm really not a wrencher, and that was the first time I have ever replaced shoe's or a caliper.

Twisting the U joints sounds like an easy check.

I let you all know what I find tomorrow afternoon. Got Jury Duty in the AM.