You are aware this is a three year old thread right? Also an 03 is a third gen(and the truck in the video is neither a second or third gen) and you are in the second gen forum.

 

I'm aware of all these things yes.. different truck but similar enough that I'd like to know what the ultimate problem was because I'm having identical symptoms..
I think it's pinion bearing or u joint maybe..
I'll try to stick the correct forums bro my bad 😆

 

I realize the thread is ancient but didn’t read of any resolution. I’ve got the same symptoms, worse when it’s cold, comes and goes but only when moving. Def not brake related, not belt squeal, not the radio, and does not change pitch based on speed, throttle input, etc. I’ve recorded 2 videos the shorter one you can hear it in the first 3 seconds but it went away, and a longer length one.