Repairing or Replacing a Doorknob

Repairing or Replacing a Doorknob

We’ve seen it a million times on cop shows: the guys in uniform leap up the stairs, guns ready, and kick in the villain’s front door.

If only the criminals had used longer screws!

Replacing an existing dead bolt, whether for extra security or because of a malfunction, is not a difficult job. Once you buy the lock, you can do the replacement in a few simple steps.

When you’re preparing to put in a deadbolt, make sure you buy heavy-duty three-inch screws. In the real world, a person kicking in your door is more likely to be a thief than a police officer. Many dead bolts are mysteriously sold with small screws, which won’t be enough to stop someone from kicking in your door without too much effort.

(The same goes for an inside chain lock. Make sure you use long enough screws to prevent someone easily kicking in the door.)
There are two basic types of dead bolts: surface mount and internal. Surface mount dead bolts are easier to install, but internal deadbolts provide more security. You probably won’t be surprised to hear that I recommend spending a little extra effort and money for the sake of your security: if you can, go for an internal dead bolt.

Check to see if your door has a hole for a dead bolt. If not, you will need a hole saw for this project. Hole saws can be found at any hardware store. They are about the size of a measuring cup, with jagged teeth, and attach to a drill, Make sure the hole saw you buy matches the size of the new dead bolt.


How to replace a dead bolt:

Out with the old:

1. Take the old dead bolt out of the door by using a screwdriver to remove the screws on the inside panel of the lock. Take a good look at how the lock comes apart. This will help when you are installing the new one.

2. Take the inside and outside pieces of the lock face and pull them apart and away from the door.

3. Remove the screws from the lock mechanism plate, which is located on the edge of the door.

4. Remove the screws from the strike plate, which is located on the doorjamb.

5. Measure the diameter of the hole in the door to be sure that you buy the same size dead bolt. Even better, you can take the old dead bolt to the hardware store to en sure that you buy the right size.


Some models may be a bit more difficult to replace due to mounting brackets or slightly different assembly. The process of removing the old dead bolt can teach you things that make puffing in the new unit that much easier, so remember the steps.
In with the new:

1. Place the new dead bolt mechanism in the hole in the door.

2. Instead of using the screws provided to attach the strike plate to the doorjamb, use longer screws that are the same diameter. This will make the lock much more secure. You may need to drill pilot holes first.

3. Put the inside and outside halves of the lock cylinder together. You can use the screws provided to attach them to each other and to the door.

4. Be sure that the bolt plate on the edge of the door is flush with the surface of the wood. Otherwise, it will keep the door from closing. If the new plate is slightly bigger than the space for the old plate, you may need to use a wood chisel to enlarge the area a bit.

5. Now attach the strike plate.

6. Take a pencil and mark up the end of the bolt.

7. Close the door and turn the latch so that the bolt gently hits the doorjamb. Repeat this a few times.

8. This should leave a mark on the doorjamb. The mark will show you where you need to place the strike plate. You may need to use a chisel to adjust the previous hole.

9. Place the strike plate in the correct spot, and attach it with the long screws, not the ones provided with the plate.

10. Test the lock a few times from both the inside and the outside to ensure that it has been assembled properly. Adjustments may need to be made.


How to install a new dead bolt:

1. Buy a dead bolt and measure the diameter of the hole it will require you to make in the door. Buy a hole saw of the same size. The hole saw will attach directly to your drill.

2. The dead bolt should be placed about 6 inches above the doorknob (from the center of the doorknob to the center of the dead bolt). Center it above the doorknob. Measure and mark this distance with a pencil.

3. Wearing eye protection, drill a pilot hole with a 1/8-inch drill bit all the way through the door in the very center of your mark.

4. Attach the hole saw to your drill.

5. Using the pilot hole as a guide, drill through the door, stopping halfway. Very important: only drill halfway! Drilling halfway from each side will prevent the door from splitting. Make sure you hold your drill level and steady so that you do not create a crooked hole.

6. Move to the other side of the door, and drill from that side until you get all the way through with the hole saw. The hole saw will hold on to the drilled-out piece of the door. You can use a flat-head screwdriver to pry it out.

7. Place the new dead bolt mechanism into the hole of the door and follow steps 2—10 for replacing a dead bolt.