How to Fix a Doorknob's Bolt Mechanism

Diagnosis

• 1

  Open the door and turn the knob into the open and closed positions. If the tongue of the bolt mechanism moves appropriately, the problem most likely involves a crooked hang.

• 2

  Close the door and observe to the best of your ability how the tongue moves as you close the door. If the door frame seems to be obstructing the bolt, the problem is most likely a crooked hang.

• 3

  Remove and reinstall the door knob and bolt if neither step one nor two applies to your bolt mechanism. In that case, the problem isn't likely to be with a crooked hang; it's likely to be with the door knob itself.

Fixing a Crooked Hang

• 4

  Tighten all screws connecting the door's hinges to the frame and to the edge of the door. If any screws no longer "bite" into the wood, replace them with longer screws to ensure a tight and secure fit.

• 5

  Check the strike plate -- the small metal tab around the hole in the frame where the bolt goes -- to ensure it still lines up with the bolt hole. If not, adjust its position so it does line up properly. Tighten the screws on the strike plate as you did the screws for the hinges.

• 6

  Check the doorknob and bolt. If they are loose in the door, tighten the screws that hold the knob to the door. If the door has a strike plate around where the bolt goes, tighten that down as well.

• 7

  Test your door. If the bolt still isn't sliding, move on to removing and reinstalling.

Remove and Reinstall

• 8

  Locate the screws that hold the doorknob in place, usually located near the base of the knob on the interior side of the door.

• 9

  Remove those screws with a long-shafted screwdriver. With shorter shafts, the knob often will interfere with the screwdriver's handle.

• 10

  Pull the two sides of the doorknob off the door. They should separate easily once the screws have been removed.

• 11

  Pull the bolt out of the door through the hole in the door's edge. This will move in a direction perpendicular to the direction you pulled the rest of the knob apart.

• 12

  Check the bolt mechanism for obvious damage, catches or breakage. If the mechanism is visibly damaged, buy a new bolt and install it according to the instructions on the package.

• 13

  Clean any dirt or grit out of the mechanism, and coat the interior surface with a thin layer of oil

• 14

  Slide the bolt back into the door, and reinstall the door knobs. Test the action of your bolt -- first with the door open, then by closing the door. If it is still not working properly, replace the lock instead of repairing it.