I am pretty lucky as i do not have the vibrator option as of yet. My truck is a 9/13 build from Mexico and i have about 4200 miles on it. I haven't seen anyone with a 2500 report the issue, or at least to this extreme so it appears that it is a 1500 issue. Based on that, it seems that it has to be the transmission, drive shaft or rear end. I would be willing to bet the reason they cant resolve it is because they are replacing bad parts with more bad parts. Most likely there is a defect in the manufacturing process that is yielding a high rate of defects and they haven't figured it out.