[Frank Messina]

Not sure what you mean by "they don't have a lock nut". Are you talking about the nut on the end of the threaded shaft on the shock? That has nothing to do with ride height. You should put a hose clamp around the body behind the adjusting collar to hold your height setting. If the shocks are worn you can send them to Naake Suspension in Roseville, CA for a rebuild. Their work is excellent and an inexpensive alternative to buying new coilovers. I recently had mine done there and bought stiffer springs as well. Great service and excellent prices.
Frank