Ok, so I took my 2015 XP1K in for the noisy front diff..... The dealer took it for a test drive and said it was the wind blowing through my windshield that was making the noise, so they took out the windshield and said it's quiet now. I laughed at him and said I know the difference between a noisy bearing and some wind noise and I know there is a bad bearing in the front diff.... he said he'd be happy to tear it apart to look for a problem, but if they didn't find anything wrong, I would be stuck with the labor bill. I told him I was very confident there was a bad bearing and I suspected it to be the pinion bearing. This morning I got a call saying they tore it down and didn't find anything wrong but I could come in and see for myself. So I did..... first thing I did was spin the pinion bearing by hand and it growled like a rabid dog in heat. It was actually catching and would stop freewheeling it was so bad. Next I tried the carrier bearings..... at first they both seemed fine but I asked for some brake clean to get the oil out and one of them was starting to make noise too. He tried telling me the pinion bearing was fine cuz it didn't have any play in it. Once I told him I was an offshore platform oil rig mechanic and I knew what I was doing, he changed his tune and said they would fix it. I also noticed the pinion depth looked to be too deep. It was only wearing on the big end of the pinion teeth which could be the reason for premature bearing failure due to the fact there would be heavy thrust load on it and suggested to slightly shim out the pinion when they put in the new bearing....... I then got the deer in the headlights look.