Quote Originally Posted by FT4NOW View Post
If I recall, they aren't nylon insert lock nuts, they are deformed lock nuts, so the female portion of the nut isn't a perfect circle. When torqued, the nut is forced into a circle causing them to lock. These types of lock nuts should not be reused.
Exactly why I didn't say they were Nylock nuts. But not all lock nuts will destroy the threads, but some types lock nuts are not designed to be reused.