I don’t believe it to be wheel bearings. Last I checked there was no play when doing the 3-9 o’clock test. Every time its gotten worse has been when I alter the driveline in some fashion.

I do need to try taking out the lift as you suggest, I just dread doing it. I need to bite the bullet. The 2wd doesn’t have a carrier bearing, its straight shaft from trans to diff.

Is there some sort of bearing or bushing inside the trans output shaft area that could wear down? The pinion bearing could make sense, I just never got any whining sound. This is a pretty harsh vibration. Another mental note I made today was that the vibration gets significantly harsher at 65 mph exactly, and coasting downhill causes a really really harsh vibration and grinding noise, the longer I coast downhill the worse it gets, almost to the point of shaking the entire rear. I’ve also noted that the flex of my suspension seems to change when the sounds and vibrations happen, like hitting a bump will make it do it sometimes. I changed the oil in the diff from 75w90 to 75w140 today to see if that would help, but to no avail.