Stumped with vibration/hum

06 4runner with 235k miles, bought as a project
Replaced all balljoints, tie rods, struts and shocks for inspection
After a few thousand miles it developed a vibration under your drivers feet with an oscillating vibration/hum with it
Sounded like a wheel bearing so I replaced both sides, (original)
Noise still there

Put on a lift and drove it, loud bearing noise from transfer case, replaced it and the rear driveshaft (hunch)
Noise still there

pulled drain plug out of front differential, metal on magnet..bingo
Replaced differential, noise still there

put 2 brand new axles in, and a ECGS driver diff bearing, noise still there

noise goes away over 60 degrees, louder and temp decreases
No change in throttle or braking, only makes noise 50mph+ and gets loud

front driveshaft u joints have no play and take grease fine
L
I’m at a loss and have 0 clue what this is, driving me nuts