I have a jeep that had death wobble. I fixed it by lining it up, tires balanced and changed the track bar. So far, so good.
Good on ya, mate.
Bad track bar is the most common cause of the death wobble in Jeeps. That is most likely what fixed it. Tire balance and alignment issues could have exacerbated it as well.
A Bad Steering Damper (5th Shock Absorber), In Jeeps That Have One, Will Create A Death Wobble.