I have a 2017 GMC Sierra, 6.2 w/ 8 speed, that also has a bad vibration while going about 50-70 mph. It started at about 25k miles, and it was after I had a tire alignment. The vibration described above is similar to my vibration, and that it feels like a rumble strip while going full speed. Things that I have notice along with this vibration: it usually only happens on very smooth road while at a constant speed, and at those speeds I can see a very rhythmic rpm uptick of about 50-100 rpm every couple of seconds wether it does vibrate or not. I’ve got an appointment for it since I’m still on warranty.
I have a 2017 GMC Sierra, 6.2 w/ 8 speed, that also has a bad vibration while going about 50-70 mph. It started at about 25k miles, and it was after I had a tire alignment. The vibration described above is similar to my vibration, and that it feels like a rumble strip while going full speed. Things that I have notice along with this vibration: it usually only happens on very smooth road while at a constant speed, and at those speeds I can see a very rhythmic rpm uptick of about 50-100 rpm every couple of seconds wether it does vibrate or not. I’ve got an appointment for it since I’m still on warranty.