These things have a short threaded post that serves to hold the inside and outside halves of the lock assembly together when the mounting screws are removed–which you have to do to change batteries. The units on our greenhouse doors were installed by the guy who built the greenhouse. I had changed the batteries once or twice, but now believe the pieces were held in place by being stuck to the stain on the doors. I removed the mounting screws yesterday to replace batteries, and found that this “hands free post” was not long enough to engage–the doors are thick.
I managed to get things back together, but it was no fun. I’m planning on getting the things apart the next time and replacing this post with something about an inch longer–but need to know what diameter and thread the existing posts are. If anyone else has fought this battle before and knows, I’d love to hear from you, as getting something that will work may require ordering online.
–Richard