I am having the pretty much the same problem,, I have 12 hrs on my 24 xp5 northstar, lots of vibration while in 4wd,, kinda like the drive shaft is out of phase/balance or the carrier bearing is junk,, took all the skid plates off last night and the carrier bearing looks to be in good shape and everything looks to be in order,, think I’m gonna put a camera under near the front drive shaft and see what it does,, i agree with JTbarlow and it actually could be a bent drive shaft from the factory,, had lots of utv’s and never have i felt this bad of vibration from the 4wd,, even my wife is like wtf is going on,,, thought about the after market drive shafts but at 1600 I’ll let the dealer deal with it, I just like to have some knowledge or proof when I get down there so I don’t get the run around and have it sit there for a month…..