I have had a 2014 bought back due to shakes and I’m in a 2017 now that has had the transmission tsb done 4 times, about 10 re-learns, aftermarket driveshaft, about 500 dollars worth of alignments, tried the spring clamps, rain danced and all kinds of other wastes. Finally I found http://www.dkgoodrich.com/contact.htm in KY. He did a dyno tune with HP tuners and so far the shake is 96 percent gone. So is the annoying downshift clunks that are embarrassing when driving passenger who thinks your u-joint just went flying. If your around KY you really need to give DK a call. Save yourself the agony of trying all that other bs. If it shakes and clunks find someone near you to tune it. None of the handheld stuff can get close. I know firsthand how bad it sucks to be unhappy with a shaky and clunky truck. I cannot understand how GM send these vehicles out to customers with such a garbage tune on them.