I've been hearing a vibrating noise underneath the truck. It sounds like it should be the exhaust pipes (metal against metal sound..) but when I checked them they are tight all the way through. I got under the truck and shook everything I could think of that could be making the annoying noise but found nothing obvious. Could something in the transfer case be causing the noise? I just had it put on a few hundred miles ago (it's used) Any other ideas? This noise is very annoying. It's hard to explain but it only happens when starting from a stop (slower speeds) when truck is working more to get up to speed. Once up to speed or even floored it doesnt make a noise.

 

try your truck in 4wd and see if the noise gets worse or any other symptoms occur