So, I removed the front DS. Very easy. Took 10 minutes. Drove it at highway speeds without the DS and no more noise/vibrations.
While removing it, I think I found the problem with the loud grinding knocking going on when the 4WD is engaged. The front DS rear CV joint is shot. The boot was disintegrated, bearings exposed, rusty dry and gritty in there. I could barely move the spline inside the CV joint.
My front drive shaft has a universal joint at the differential and a CV joint at the TC. I can't seem to find a diagram of this set up on the web? I'm hoping I can just replace the CV joint and the spline as a unit rather then buy a whole new DS which I can't seem to find mine anyway. Any thoughts?