New tires cured mine. You have a classic case of death wobble. Mine started at about the same mileage as yours running the stock goodyear wrangler 30" tires. The dealer said that the tires had plenty of mileage left on them, I had the tires rotated, balanced and had the Jeep aligned. None of this worked. As soon as I put on the new tires, it went away. Actually the new tires made my jeep ride like an entirely different rig.