Repair door lock


The repair of a door lock consists in most modern locks from changing a lock cylinder. He is, however, only the heart of the entire door lock. It consists of a mechanical locking mechanism in which individual parts can be repaired.

Construction and springs

The door lock consists of two lock plates, which are connected at the head side with the forend. The forend is visible after plugging into the door lock box with latch and latch. The bolt is moved by the lock cylinder. The latch is the snap bolt above the latch.

In the door lock are three springs, of which two of the trap give their tension. The latch spring pushes the latch outwards and a counter spring accomplishes the opposite direction. The bolt is locked by a tumbler spring. It prevents movement outside the current closed position.

The three heavily loaded springs are usually the cause when a door lock needs to be repaired. A broken spring is relatively easy to use. For this purpose, the door lock must be screwed on one side. The new spring is inserted and clamped with manual force.

Replace instead of repair

The other mechanical parts in a door lock transmit closing force, block the closed state and regulate the access of the doorknob to the case. Repairing by replacing individual broken or bent items is not worthwhile. Often the repair is even impossible by sealing.

The modern mortise locks are inexpensive and spare parts are almost not available. If the locking mechanism does not work despite the correct locking cylinder, a new mortise lock should be installed. The intact lock cylinder can be used again.

If closing the door lock becomes more difficult or blocked, causes outside the door lock can also be the cause.

  • Door has warped and bolt and trap are no longer fit. The counterpart of the forend, the striking plate can be carefully filed.
  • Door lock is dirty or rusted. Spray the moving parts with Caramba or WD40 spray. Do not use oil.
  • By violently beating doors, for example by pulling the mechanism is easily slipped or tilted. Try to strike the removed door lock again with light blows.

Tips & Tricks

When buying a new door lock, pay attention to the closing direction. There are right and left-closing castles. In case of doubt, take the removed door lock as a sample.


Video Board: How to Repair a Door Lock. THE EASY WAY!