Thanks to all for the help. The answer to my problem was simpler than I thought. I used an impact wrench to take the nut off the tie rod end. I destroyed the inner plastic threads on the self locking nut. It was just spinning- I thought the stud was spinning. I used a chisel and broke off the nut- put a new one on and it tightened right up. Moral of the story: Dont use impact wrenches on self locking nuts. They are fragile. Volvo recommends replacing self locking nuts everytime you take them off. You probably dont have to do that. Just take your time and remove with a wrench or socket.