Vibration only in 4wd

I seem to be having the opposite vibration than a bad needle bearing. Truck vibrates (pretty bad) only in 4wd and goes away in 2wd. When this happens, the truck pulls to the right slightly, so I'm assuming it is on the right side.

The vibe is the same whether going strait or turning, reverse or forward. And gets louder/heavier with speed increase.

The vibration feels like the tire has a bubble in it (obviously does not), and has a drag spot to the vibration--meaning that if I am almost stopped, I can feel something grabbing or stopping the rotation.

Changed front diff, rear diff and transfer case oil 5k ago.

CV axle? but if it turns all the time why would the vibe only occur in 4wd.

I have yet to get it up in the air, but plan to soon.

2006 Tacoma 4x4, TRD, 175k