Spray lubricant directly into the keyhole. Insert the key and see if the lock now turns smoothly. Wipe any lubricant off the key with a rag or paper towel. If the lock still sticks, you will need to disassemble, clean and lubricate the doorknob assembly.
Unscrew all the screws on the lock's faceplate, located on the side of the door. Unscrew and remove the screws that hold each doorknob in place.
Pull the doorknobs out of the door, one after the other. Pull out the bolt from the faceplate hole.
Spray lubricant on all the moving parts except for the lock cylinder, which is the spindle attached to one of the doorknobs that goes through the hole in the door. Wipe all parts clean with a rag or paper towel, being careful not to get any lubricant on the lock cylinder. Wipe off dirt from the non-moving parts.
Coat the lock cylinder with powdered graphite. This lubricates the lock cylinder without attracting dirt.
Push the latch assembly into place in the side of the door. Insert the outside doorknob, lining up the screw holes in the doorknob to the screw holes in the door. Insert screws in the latch assembly on the side of the door, but don't tighten them all the way.
Place the inside doorknob on the spindle coming through the door from the outside doorknob. Tighten the screws on both doorknobs almost all the way.
Turn the knob and the lock to make sure they are working smoothly. If they do not turn, turn the doorknobs until all the screws line up with the screw holes in the door. Once the doorknobs and lock turn properly, tighten the screws the rest of the way.
Things You Will Need
- Spray lubricant, such as WD-40
- Rag or paper towel
- Powdered graphite
- Your lock may have a small knob instead of a full-size doorknob on the inside of the door. When disassembling your lock, unscrew and remove this small knob just as you would a full-size doorknob.
- Lay all parts on a cloth on the floor so that nothing gets lost.