I replaced my slide out locks about 18 months ago. However, after all the time and money, I'm not sure they are absolutely necessary.
Monaco only installed locks on the drivers side front slide. None of the other slide outs have locks.
Our slide locks were broken when we purchased the coach a few years ago. Camping Worlds solution for jammed slide locks was to cut the stainless steel plates across the bottom. The locks had been neglected since new and the inside cables and springs were completely rusted out.
I drove the coach 2500 miles with the locks not working and had no issues.
I purchased new slide locks from Sue at Veurinks RV parts. More information on replacing slide out locks:
http://www.irv2.com/forums/f115/slid...lp-416803.html