Feb 13, 2019
What are the parts of a garage door system?

What are the parts of a garage door system?

Garage door systems aren’t the most complicated things on the planet, but they aren’t just a door and electric opener either. Modern garage door systems are made up of over a dozen different essential parts and any one of them can affect the operation and safety of your door. It’s hard to fix something if you don’t know what it is, so here’s a basic introduction to the main parts of a garage door system.

The star of the show is the actual garage door itself. This is the most visible and largest of all the parts, so it’s a big deal. Literally. The door itself generally comes in sections for single-car doors (8 ft. wide x 7 ft. high), double-car doors (16 ft. wide x 7 ft. high) and custom doors of nearly any size. The options for the look of garage door panels are nearly endless. Door panels can be raised, recessed or smooth and can have windows or not have windows. Doors can be made from steel, wood, aluminum, fiberglass or vinyl, but steel is by far the most popular due to cost, strength to weight ratio and ease of maintenance. Garage doors can be virtually any color you want and there are a wide variety of steel doors that even look like real wood.


This is the part we all know, the big box mounted above your car that magically lifts the door up, just by pressing a button. Cool right? We agree. Other than the spring, nothing has been more revolutionary in the garage door world than the electric opener, and it has become a mainstay in the American garage. For homeowners these days, not having an opener would be like having a washer, but no dryer. Like having a refrigerator, but no freezer. Or, worst of all, like having a TV with no remote! Not a pretty picture. Garage door openers are also the most complex of all the garage door components and are the only part of the garage door system that requires electricity and a small computer (logic board) inside it to operate. There are many brands of opener, but under the hood they all have the same basic parts, including a motor, gear, logic board, radio receiver, chain and others. When all of these parts are in good condition they will work together and provide you with that “magic” we all love so much.


Springs are the metal coils that do the heavy lifting in raising or lowering your garage door. Springs come in two varieties: torsion and extension. Torsion springs are the most common and sit above your garage door. Extension springs run along the top portion of the track on each side. Torsion springs get their energy from being twisted, where extension springs get their energy by being stretched. Torsion springs are thought to be significantly safer and last longer, on average, than extension springs, so extension springs are being widely phased out of use.

While both types of springs are pretty safe from a distance, they can be very dangerous up close or when servicing them. We always recommend you call the local experts at Reliable Garage Door for any springs that need service, installation or repair.

Tube shaft

The tube shaft is directly above the door and holds the torsion springs in place so the torsion power can be transferred to the drum and raise the door. Only doors that use torsion springs will have a tube shaft. If a door operates by way of extension springs, there is no need for a tube shaft.


Garage door drums sit on both ends of the torsion bar and spin as the door goes up or down, rolling up the cables or spooling them out. These help to stabilize the door and keep the cables taught so the entire system stays balanced.


Lifting cables run vertically, from top to bottom, on each side of the door. Each cable connects to the door at the bottom and the drum at the top. These cables are the connection that transfers the force from the spring, which makes the door much easier to lift.


Just like a railroad track, the track in your garage door is what keeps everything traveling in the right direction. The track houses the rollers and guides the door as it raises and lowers. Tracks are made from steel and they can be installed at standard heights or non-standard heights for spaces with low headroom.


Rollers move along the track and allow the door to travel smoothly when opening or lowering. Rollers are generally made from steel or nylon and can affect the amount of noise your system makes. Nylon is generally thought to be more quiet, but contrary to popular belief, the number of bearings in each roller has a greater effect on the noise produced than what the roller is made from.


A garage door retainer is a metal, aluminum or plastic piece that runs along the bottom of the door and holds the bottom seal in place. Retainers come in different styles and are typically replaced in tandem with bottom seal because they are so closely connected.

Bottom seal

The bottom seal is the rubber or vinyl piece on the bottom of the door. It runs along the entirety of the panel and is used to form a tight seal with the ground to keep out pests, insects, blowing snow and Green Bay Packer fans. OK, maybe not Packer fans, but it does block the freezing wind that blows through Minnesota during the winter months, making it essential for energy efficiency in attached garages.

Safety sensors

All garage door openers produced since 1992 have infrared safety sensors that can detect if something is in the path of the door and stop it from closing on people, pets or objects. The sensors are generally small boxes or tubes and they are placed less than 6 inches off the ground, one on each side of the door.

While these parts of your garage door are the most likely to impede or stop its operation if they fail, this is not at all an exhaustive list of every part of a garage door system. Yours may include others or use different terminology depending on the exact style and model. But by identifying the basics, you can be better prepared to handle any maintenance issues that come up.

Lastly, always remember that if you have any questions at all, we are just a call away. All our technicians and even our customer service representatives are well trained in all these parts, so we can handle whatever questions you may have.