I see in your sig you have a Ford 8.8 in the rear, what in the front?
Was this "noise" happening in 4x4 and stopped when you took off the DS? Maybe I'm reading the post wrong, but it sounds like you were running in 4x4 constantly and took off the DS to get a noise to go away.
If not, it's prolly the transfer case. If you have a locking front diff, put it in 4l and lock it and see if she crawls. If so, then it's a wheel bearing or an axle. If not, it points you back to the tcase.
I don't know of a good way of troubleshooting the tcase. Maybe someone else does.