One thing which has always annoyed me is when a lock nut is combined with a carriage bolt. Especially if the square hole is not a tight fit with the bolt head, and the bolt is really long. From discussions which I have read on this forum, the carriage bolts were originally tack-welded to the engine bracket but don't hold up over time. If you were to weld the carriage bolts more securely, you could use any kind of lock nut that you want and not have issues when it is time to take them off. I suppose if you used a nylon lock nut, you could heat it with a torch to melt the nylon to make it easy to remove the nut. Now I need to log off and get out and practice what I preach and loosen mine up and hope I have a gap to eliminate the vibration in my truck.
