A single-cylinder deadbolt lock consists of a shallow cylinder that accepts a key on one side and a deadbolt that slides through the edge of the door into the door frame. A deadbolt is mounted at least 6 inches above the door knob and has a thumb latch on the inside face of the cylinder. Problems with either the deadbolt or the cylinder portion of the lock can make it sticky and difficult to operate. Instead of going to the expense and trouble of replacing a single-cylinder deadbolt lock, repair it instead.
Step 1
Remove the two screws on the back of the thumb latch with a Philips head screwdriver. Remove the thumb latch to expose its mounting plate. The two screws on the mounting plate hold the lock together. These only need to be hand-tight. It they are over tight, they can make the deadbolt difficult to turn. Loosen the screws about half a turn each. Replace the thumb latch. If the bolt still does not turn easily, proceed to Step 2.
Step 2
Insert the narrow nozzle on a can of Teflon lubricating spray into the key slot on the cylinder a quick spray. The Family Handyman recommends Teflon spray over traditional graphite as it leaves behind a dry powdery residue that keeps locks lubricated longer.
