this is about the best i can do to record the noise. it only happens:

between 30-50 mph
doesn't matter if im accelerating, braking, or cruising
also doesn't happen every time

i've looked underneath and found nothing that is loose that would be rattling.

try and block out the exhaust and listen for a noise. can best be heard up until 5-6 seconds and again starting at 22 seconds.

http://www.youtube.com/watch?v=7istq...ature=youtu.be

 

weird man. i mean it sounds like something making revolutions so either in the tire/brake area, or a shaft/gear. id say check the rotors and drums, and maybe around the tcase/shaft area.

 

Do you recall running over any hitchhikers or homeless people that could be stuck in the undercarriage?

 

Front drive shaft? Cat heat shield? Gas tank heat shield?

 

50/50 Dry cross joint, most likely the front one on the rear drive shaft.

 

ummm, no i think i got rid of all those last oil change!

no cat so no heat shield. and like i said i literally check anything and everything that can be moved.

just weird that it only does it between 30-50 mph.

 

So the gas tank shield maybe? The turbulence under the truck can cause weird things to happen(I actually remember a thread a couple years ago with that prob). My laptop cooling fan is vibrating more than your noise in the video LOL. So maybe I'll wait to fix that(when the fan comes from japan) before listening to the vid again.