Death wobble (DW), can be cause by MANY different things in the front end. Make sure that all of your steering linkage is tight, as well as the steering box itself. If they are all tight, then move on to the track, or panhard bar. If either of the joints on the ends are loose, you can have DW. From there, move on to the ball joints and suspension linkage. Check your alignment, and your wheel balance too. Unfortunately, DW is a very broad problem, with only one symptom!! I just rebuilt the ENTIRE front end of my XJ because of worn out parts, and DW!!