I was very close to trading my 2016 GMC Yukon Denali due to the extreme shaking and vibration coming from the tranny/rear area of the truck. As some have described, it was like going over rumble strips. Took it to my dealer and they diagnosed it as a torque converter issue. They drained the trans fluid as per the TSB and it now drives like a new truck. The best part is it was covered under warranty. The GM instructions are to drive it at least 200 miles but the difference was immediate.