Vibration from ladder-type skid plate.

[finall]

Update:

Thanks to a combination of EVERYONEs help I have solved this difficult and persistent problem.

After the dealer fixes the UCP, I still had some vibration. I removed it, and vibration disappeared. I looked at it, and it was still warped.

So I took the advice and ran over it 17 times with the H2, blocking it with wood bits, and CAREFULLY and slowly almost perfectly straightened it. Took a while to do this, since I had to not only straighten it, but take a warp out of it.

Then I made rubber washers for the back 3 bolts that went between the UCP and body. On the front part, I glued strips of the same 1/8" thick rubber on the last upper half of 4" of the UCP, where it tucks under the front skid plate. Also, I glued similar strips on the upper side of the metal cross pieces with the bolt holes in them.

This way, the entire UCP is isolated against the vehicle frame by the rubber. It worked! Took a 200 mile spin in the H2, with zero vibration. So either the rubber isolators did the trick, or just unwarping the UCP worked. Either way I am really stoked about getting this fixed!

Thanks for everyone's help!