Ok, I'll do that. There may be a little when I let off the gas. The truck is pretty smooth, but not so smooth that I would definitely notice a small amount of vibration unless I was really feeling for it, so I'll pay more attention. I climbed under yesterday and shook the d-shaft but didn't spend too much time...got caught up getting my mudflaps on & starting to finally add power steering.
How much play is acceptable in the d-shaft? I can get it to rotate a bit less than 1/4". Doesn't seem to be u-joints, though, since I see it moving at the back of the t-case and the rear diff. Is a little play there ok? Otherwise I couldn't get any more movement. I'll get some u-joints and see where that puts me.