I recently just found out from a friend that normally 80 % of the time the
"death wobble" is caused by the cummins torque monster which twists the frame and causes the rails to flex and fatigue. He was able to fix this problem with one of these Dodge Steering Stabilizers and it has lasted a little over a year. You can check them out since that where he got his or shop around, i heard a place called thouroughbred diesel also has decent ones available