Well I loosened up all nuts and bolts, Tried to realign the pipes so that the pipe that crosses under the trans would not hit. I could not get the proper clearance. So I snugged up all the bolts again. then I wedged a steel pry bar between the trans and the pipe and wacked it a couple of times with a hammer and a piece of wood so as not to damage the pipe. This worked and nothing is touching. The very bad viration went away to be replaced with a milder low vibration only when cold and in drive. As soon as I give it a little gas it smoothes out, and driving is fine.I had a friend look at the system and I went from N to D  to see if anything was touching. Then I looked and he did the same. Both  us didn't see anything touching. I decided to put a thin rubber cushion between the muffler bracket and where it bolts up to the van. I figured this might isolate the vibration a bit. No differance. I think this is the way it just is.
By the way this makes 3 days. I am going to drive it a few days and see if I can pinpoint the problem.
John  1990 vanagon gl