I have 2011 Yukon Denali XL also has broken motor mount. Terrible quality GM. Saw these threads. Emailed GMC customer service they said take it into GM dealer for diag before they can determine whether or not GM would help with repair costs. Then called them to let them know that it was at my local GMC dealer. They then changed their mind while they were on the phone with me, before diag had been done, and said they were not willing to help at all. $65 k new. Has 118k miles and THEY told me to take it to GMC dealership. I do so and they then tell me before knowing what's wrong, they won't help. Now I have two $100 diag fees because I listened to GMC customer service. They said they can't help because vehicle out of warranty. Looks like the above vehicles were out of warranty as well. Hmmmmmm. Awful service. This is like my 10th GM SUV. No more.