One problem related to differential unit has been reported for the 2015 GMC Yukon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2015 GMC Yukon based on all problems reported for the 2015 Yukon.
Vehicle exhibits a "buffetting" or pressure sensation that can be felt primarily in the ears between 40 and 50 mph. After any amount of time at these sustained speeds it begins to cause dizziness, ear pain, and headaches. This condition was confirmed by the dealer with 3 separate drivers including a tech, the sales manager, and the owner. Gm has a technical pi issued, as the problem is apparently relatively common in these vehicles. Suggested repairs include re-bonding the roof sheet metal to the frame, repair/replacement of the rear differential, replacement of the propshaft, repair/replacement of wheels and tires, removal and "relaxing" of the exhaust system, and more. None of which appears to solve the issue. A quick internet search turned up dozens of cases with this issue in just one website. Gm has manufactured a vehicle with a significant, known flaw that they cannot currently fix. This flaw should be considered a safety issue strictly based upon the physical symptoms triggered by the sensation within the vehicle.