How to Install Garage Door Locks - DDM Garage Doors Blog

Posted September 22nd, 2017 at 5:12 pm by Dan Musick

Garage door locks are normally installed in the center of the section just above the bottom section. Here are instructions on how to install the two most common lock assemblies we sell.

Diagram of a garage door lock assembly.

The more common lock assembly uses a cable to connect the outside lock keyed T-handle to the spring latches. The cable runs from the spring latch on one side through the center inside the release handle and on the other side where a track bolt and nut secure the cable to the spring latch. On single-car doors there is often only one latch.

Garage door lock assembly kit showing all the parts.

Whereas, the other system uses two sash chains and small S-hooks to link the inside handles and spring latches.

Parts for lock assembly that uses sash chains and s-hooks.

If you have a foam-filled door with steel on both sides, the metal on each side will compress when you tighten the screws that secure the outside handle to the inside handle. To prevent this from happening, you will use the two red spacers above.

The order of installation is as follows.

I. Install the outside keyed handle and the inside release handle.

Drilling for the lock will be a two-step process. First, drill three holes with 3/16″ bits. This is key to a properly aligned and functioning lock.

Template showing hole sizes and recommended drill bit sizes.

After drilling these holes, larger 5/16″ holes and a 3/8″ hole will need to be drilled on the outside skin of the section only, but not on the inside. Sometimes the 3/8″ hole needs to be enlarged slightly.

Template for the outside skin only showing recommended drill bit sizes.

Most steel doors are either pan doors with stiles joining the edges of the sections or sandwich doors with steel on both sides bonded to the insulation.

Instructions for Installing Locks on Pan Doors

  1. If you have a pan door, locate the center stile, and the holes punched for the lock. These may be centered, as you see in this insulated pan door . . .
An image of the center stile on a pan door.

or slightly below center, as you see in this hollow, or non-insulated door. Notice how the lock lines with the holes.

A person aligning a garage door lock into the center stile holes.
  1. Drill three 3/16″ holes from the inside using the holes in the stiles as a guide. Then, center the drill bit in the holes and perpendicular to the section and stile. Also, check the outside of the section to make sure the holes are evenly spaced.
  2. Drill the three larger holes in the outside skin only of the door. Faster speeds are better because slower speeds tend to rip the thin sheet metal.
  3. Insert outside lock T-handle.
  4. Then, install the inside release handle.
  5. Install the two long screws that connect the inside and outside handles.

Instructions for Installing Locks on Sandwich Doors

Locate the outside stile where you want to install the lock. This would normally be in the center of the section. On odd-size doors, it will be off centered. The outside T-Handle installs vertically or horizontally, as shown below.

CHI garage door with horizontal T-Handle installed.
  1. Drill three 3/16″ holes from the outside and into the inside skin of the section. The drill bit must be perpendicular to the outside of the section. Afterward, check the inside of the section to make sure the holes are evenly spaced.
  2. Drill the three larger holes in the outside skin only of the door. Faster speeds are better because slower speeds tend to rip the thin sheet metal.
  3. Cut the red spacers, so they are flush with the outside skin of the door section and install them over the two posts that go into the 5/16″ holes. Then, insert outside lock t-handle.
  4. Install the inside release handle.
  5. Furthermore, install the two long screws that connect the inside and outside handles.

II. Install the spring latches in the center at each end of the lock section.

  1. Screw the latches to the ends of the sections.
  2. Then, connect the latches and center release handle with the cable or sash chains. Also, pull them to tighten them. The lock will not work if the chain or cable is loose.
  3. Test the outside lock handle. If the latches don’t pull when the handle is turned, remove the inside handle and turn the outside T-handle 90 degrees.

III. Install the garage door lock strikers.

  1. With the door closed, align the striker with the spring latch and secure the striker with two track bolts and flange nuts.
  2. Then, drill additional holes as needed.
  3. Test the lock to ensure it works.
  4. Finally, lubricate the latch and inside release handle.
An image showing how the garage door striker and latch align.

Here’s how the striker and latch align. Some installers bend the latch to get better traction.

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