The guys came back with a problem, again, vibration in 4wd but OK in 2wd. I am thinking selector on front of diff. Any thoughts?

[2015 Z Force 800 53/Trail EPS]

I would check the front driveline for bad U-joints or carrier bearing...then take a close look at both sets of front CV joints...put some load on the front in neutral and look for any movement in them.

But all that rotates in 2wd as well doesn't it?
I think maybe the "vibration" reported is actually jumping the splines and that means the selector fork is bent or  the plastic teeth stripped as 'someone' went from 4wd to 2wd, no problem as it just slips out but then tried to go back into 4wd on the move, under load and bent the selector or damaged the teeth on the rack etc so the dog doesn't fully engage.
Anyway, stripped out the smashed one and ready to strip the 'vibrating' oe as soon as they stop hiring 100% three ties a day.
At least it looks like I can get the electronics off in the frame.

problem solved, I think. Belt went BOOOOOM! I thing it was on the way out and the extra load in 4wd made  it vibrate. But what a malarkey to get to it, half the interior stripped down just to get to the two front bolts of the CVT case. Needless to say, no one here has any belts. 939 x 35.9 guess it will have to be a 939 x 36.7