I have an 04 with 4 button 4x4. Ive checked the vibration with all 4 wheels off the ground and in 2hi front wheels not moving there is no vibration. In 4hi the vibration is there. Ive replaced both hub assemblies and brake rotors with no resolution. Is there anyway to check one side at a time? Like disconnect the vacuum hose to actuator to simulate a 3 wheel drive in 4hi.

 

Why not remove the front drive shaft and drive it in 2WD & 4WD? If the vibration is gone in both modes, Check the universal joint and the CV joint on the shaft.

 

Heard driving without front drive shaft with nv236 transfer case will do damage

 

Won't hurt it a bit. Transfer case could care less if the shaft is there or not.

 

With the four button 4X4 the front drive shaft is constantly spinning. Like I said no vibration when in 2hi with shaft spinning. Vibration in 4hi with shaft spinning. I think Ive narrowed it down to the front differential just trying to see what side now.