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Home Door Lock Maintenance

Keep locks from sticking…so you won’t be outside…knocking and kicking…

On this day, in 1851, Mr. Yale patented the door lock. By 1852, his invention was sticking and difficult to turn. Soon thereafter, it froze solid -- and he was locked out. And, in 1853, he broke his first door key trying to turn his lock. Today, 200 years later, little has changed. While locks have gotten better, time, dirt and inside goo, still gum things up -- sometimes preventing Yale’s invention from doing what it’s supposed to do. To prevent or eliminate this problem, give a sluggish lock mechanism a shot or two of penetrating spray lubricant like WD-40. Don’t use regular lubricating oil, which collects and holds dirt; this will make locks even harder to operate over time. Once things are operating smoothly, an occasional spritz of WD-40 will keep locks working well. An alternative solution is powdered graphite, from the hardware store. Or, you can rub key edges with a soft lead pencil, insert the key and transfer graphite into the lock mechanism. .

Door Lock Fix

Repairing an old door lock that no longer locks when the door shuts. Part of the problem is that the strike plate is not recessed deep enough in the door.

Tools needed:

hammer
chisel
file
screwdrivers
Emory cloth
brass screws

Steps:

1. Remove the plate from the lock. Some locks have another plate beneath the first one, and you will have to remove the entire doorknob mechanism.

2. Slide off the interior doorknob by pressing in on the retaining pin with a small screwdriver. Slide the knob off once the pin is depressed.

3. Loosen the screws on the inner side of the lock and slide the mechanism out.

4. Use the hammer and chisel to deepen the socket for the strike plate.

5. Run the fine edge of a file over the end of the locking arm until it's smooth and shiny.  Gently file in one direction and polish with an Emory cloth.

6. Reassemble the lock and test the door.
 

Padlocks

Here are a few tips that will help you keep your padlocks working efficiently:

1. Lubricate padlocks periodically with a light machine oil. Do not use graphite in any form! Your padlock is a precision instrument, and graphite may actually cause the locking mechanism to stick. Apply oil in both the keyway and shackle openings.

2. Padlocks used outdoors may require occasional cleaning. To do this, submerse them overnight in kerosene -- let them dry thoroughly -- and apply oil.

3. Your padlock is only as strong as the hasp on which it is hung. Use only a strong, plated hasp with concealed screws. An un-plated hasp will cause rust to drip down through the shackle opening into the mechanism of your padlock.

4. When a padlock is operated infrequently or exposed to severe weather conditions, internal working parts may become tight. In these cases, it is suggested that you exert a slight downward pressure on the shackle while the key is being turned. Doing this 3 or 4 times will relieve any tension and will usually restore easy and normal operation of the padlock.

Auto Door Hinges

Door hinges require periodic lubrication to keep the door operating properly. The technician should understand the parts and operation of the door hinge assembly.

Each door has two hinge assemblies: one on the top of the door, called the upper hinge, and one on the bottom, called the lower hinge. Each hinge assembly has two basic parts: one attached to the body and one attached to the door. Most hinges are bolted to the door and body. The bolt holes may be slotted to allow the door to be moved slightly for proper alignment.

A round pin called a hinge pin is solidly attached to one side of the hinge assembly. This pin fits into holes in the other side of the hinge assembly. When the door is opened or closed, the hinge assemblies rotate on the hinge pin. The space between the hinge pin and the hole it rides in must be lubricated for the hinge to move properly.

One of the two hinges is usually equipped with a door check. The door check is used to hold the door in an open position after the door is opened. The door check has three basic parts: a door check cam, a door check roller, and a door check spring.

The door check roller is attached to the body side hinge. The roller fits into grooves in a cam that is attached to the door side of the hinge. When the door is opened the cam moves and the roller rolls on it until the roller fits into one of the grooves. With the roller engaged in a groove, the door is held in an open position. There are several grooves so that there are several positions for holding the door open. The door check spring holds the cam and roller in contact with each other. The door check roller and the slots in the door check cam each require periodic lubrication for proper operation.

Door Latch Assembly

The door latch assembly on a car door is another area that requires periodic lubrication. The door latch assembly holds the door closed and allows it to be locked. The parts of the door latch assembly that you see on the outside of the door are the door handle and the part the key fits in, called the door lock cylinder.

Most of the door latch assembly parts are located inside the door at the opposite end from the hinges. . Operating the door handle moves a linkage rod, which in turn opens and closes the latch mechanism on the part of the door called the door jam. The latch mechanism must be strong enough to hold the door closed even if the car is involved in a collision.

When the door is closed, the latch mechanism engages a part on the car body called the striker. The striker is mounted to the body pillar. Some strikers are a stud or bolt that the latch mechanism engages like the one shown below. Other cars use a part called a striker plate, which the latch mechanism can engage.

The door lock cylinder allows the driver to lock the door. The lock cylinder and related parts fit inside the door as shown below. . The door lock key is inserted in the lock cylinder. Turning the key turns a pawl at the end of the cylinder. The pawl engages a connecting link to the door latch assembly. When the lock cylinder is in the locked position, the connecting link prevents the door latch mechanism from operating; the door cannot be opened.

Lubricating the Door Hinges and Lock Mechanism

The door hinge and lock mechanism of each car door should be lubricated each time your car is serviced. These parts are often overlooked. A door hinge assembly that is not properly maintained will result in a noisy, hard-to-operate door. An improperly maintained lock mechanism will result in locking and unlocking problems.

The first step in lubricating the hinge and lock mechanism is to look up the correct lubricants. The door hinge assembly requires lubrication on the moving parts of the hinge pin. Most hinge pins are lubricated with engine oil. Put the correct type of oil in a small squirt can. Use the oil squirt can to lubricate the hinge pin.

The door check part of the hinge also requires lubrication. You will need oil and grease for this area. A special door grease is available for these parts. This grease is made from materials that do not attract dirt. This is an advantage because door check parts are unprotected. Open the door wide to get access to the parts. Use the oil squirt can to oil the roller pin. Apply grease to the door check cam. While you have the door open, you can lubricate the striker plate assembly of the lock mechanism.

WARNING : Never spray any lubricant into a lock cylinder until you check the shop service manual. Using an incorrect lubricant can cause the lock mechanism to "freeze up" and prevent the key from turning.

The door lock cylinder is typically lubricated with a water displacement lubricant like WD-40. Place the spray can nozzle tube into the lock cylinder. Spray a small amount of the lubricant into the lock cylinder. You do not want excess lubricant running out of the cylinder and onto the car paint. Be sure to wipe off any excess from the paint. Try the key in the lock cylinder and be sure it works properly.

After lubricating the door hinge and lock mechanism, operate the door and the lock several times. Be sure to clean off any excess lubricant from the parts. Remove any lubricant that came off your hands from the door handles and paint.

WARNING : Always wipe any lubricant spill or overspray off paint with a soft rag. Lubricants can damage some paints if not wiped off promptly.

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