About 6 months ago I noticed a "rattle" when I was starting out or when the engine was under load. At first I thought I fixed it with the volume *** but as I have been doing alot traveling lately I need to keep the radio low so I can talk on the phone and the rattle was driving me nuts. Every so often I would climb up under the truck with a rubber mallot to see if I could recreate it. I took off several skid plates and heat shields to no avail. This morning with the assistance of my daughter I found it. There is a heat shield on the passenger side of the transmission that had a crack in it. Not sure what kind of metal it was I decided to remove it and burn a bead of weld down the crack and to my surprise the rattle is gone. Here a couple of photos to show how I fixed it. Since it has been a year since I have welded it is not pretty but since it is under the truck I say no problem.

 

Nice weld... Wish I was that good with my pocket mig