As a former Jeep owner, I can tell you that, first, death wobble is a common issue among those of us who have modified our Jeeps, and secondly, you are doing everything right, because the cure for the dreaded death wobble is very elusive! The usual culprit is the track bar bushings (why do the British say 'bush'?) so when you replace those it should go away. Perserverance is the key! I'm getting the beginings of theat in my '01 with 125k miles, so I'm right behind you!