I'd look an see if the caliper is sticking after it's been driven a while. Again, if the rears are out of adjustment the fronts will get over worked.
One thing that you haven't looked at is the kingpins. If yours is a 1 ton, you should have a dana 60 front axle. which would be equipped with kingpins instead of ball joints. if the king pins are worn they will cause a shake when you get on the brakes. They shouldn't cause the rotors to warp, but they will cause a nasty shake over a bump or on the brakes. Otherwise known as Death wobble.....Hop over to
www.CK5.com and search on death wobble. You will find a ton of posts on the subject there.