For what it's worth, I went through a round of crap with a bent/twisted drive shaft. I had a GMC 1500 years ago (don't burn me too bad) and I got rearended. I was in school at the time. Insurance was paying so I took it to the stealership and let them fix it. Well, a few months later I developed the classic squeak in the driveshaft... bad u-joint. It had enough miles on it I didn't think much about it. It was one of those ******** that used the injected plastic to retain the Ujoint from factory (the guy that designed that ought to be
) I ended up bending a yoke a little getting the joints out. I guess you'll have that beating them out in a parking garage. Anyway, I took it to a driveline guy in town to change the yoke and he stuck it in the lathe and spun it up and stopped it and said, what the F@#$% did you do to this thing? I had checked it rolling it on the floor but I couldn't see it mainly because it was more twisted than bent. AS it turned out, that wasn't the only thing that was still wrong after the wreck and I won't go to further details but suffice it to say after eating a t-case, replacing it and eating another, I got rid of it.
The moral of the story is it's really hard to tell the condition of a drive shaft unless you put it in a lathe or a balancer and spin it. Then the runout will become painfully obvious. It was really cool watching the guy straighten it though. He was good. I stood there and watched the dial gauge for the runout.