SUPER loud hum at all speeds but 55mph

[E.T.]

Took the front driveshaft out today, much quieter, but only as there's less to rattle.. Still getting the vibration so I guess it has to be the rear diff, the driveshaft or the transfer case (hopefully not anything in the transmission itself..). I'd still like to know if anyone else has diagnosed a driveline vibration and come up with a specific bearing or something that was at fault- tomorrow I'm putting the front shaft back in, taking the rear one out and going out for a spin- assuming that if I still get the vibration it has to be something in the transfer case, otherwise the driveshaft or the diff. It seems to peak at 45mph for now.

 

[Mbrooks420]

It’s probably the rear end. It’s super common on this generation.

 

[E.T.]

It’s probably the rear end. It’s super common on this generation.

Put truck in neutral to reinstall front shaft, was removing rear one to test theory and had enough play to notice the rear U-joint was mullered. Fixed for now!!