Couple things here- just installed a 3" suspension lift from zone, with a transfer case drop (I know, not ideal but I don't have the money at the moment and I needed new tires so now was the time).
At any rate, I seem to have some vibrations, but I only feel them when starting up, i.e 1st and sometimes 2nd gear. I can also feel it slightly when I step on the gas with a trailer behind. I don't notice this when in four low, and I also feel that the front u joints need replacing. Does this make sense? I would have thought driveline vibes would be more noticeable at higher speed.
Second, different question: my front (and probably rear) pinion leaks very slightly. Reading around it looks easy to change the outer seals...is it? And is there an inner seal? I found no reference to one. Incidentally the pinion leaked before the lift they are not related.