Brother had a noise and vibration in the front of his brand new xp 1000 so we got to checking it out and narrowed it down to the front diff with a mechanics stethoscope. Pulled it apart along with a 2014 xp1000 diff i installed on my old xp900 that sounded good. After comparing to 2 diffs found that the 2014 had .026 gap between the pinion gear and housing. The 2015 only had .010 gap. Found a shim on the 2015 diff between the pinion bearings and pinion gear. Pulled the shim off and reinstalled between the bearing and snap ring which gave it the same amount of clearance as the 2014. Put diff back together, installed it in rzr and the noise and vibration is 100 percent gone.