Don't cook it so long. Real hot charcoal or wood fire (I will not cook on a gas grill), steaks about 3/8in thick, just a couple minutes a side over the hot part of the fire.

This is what I do. Thaw the steaks, cool but not frozen, season and set aside. Start fire. Cook potatoes and veggies. Put steaks on fire, don't walk away or you will over cook. Flip often. Give a total of a couple minutes a side.