I have a completely stock 2018 2500 4x4 Cummings that has 185k miles on it. It started having the vibration about 25k miles ago. I thought it was the tires and replaced them with the same brand of tires that has been on it for 150k miles (3 sets) from the same tire shop. Made no difference, had them rebalance and trade fronts to back, still the same. Took the truck to driveline specialist shop and rearend speciality shop, both told me they could not find anything wrong. Vibration starts about 65 and goes to 80. After reading several forums about this issue, I’m going to drive it until it explodes and then I’ll buy a new one. I’m not going down that rabbit hole. It sucks because I really like the truck and have never had a problem until now.