Garage Door Parts: Names and What Each One Does
Updated November 2026 · A plain-language glossary
A garage door has a surprising number of parts, and homeowners often cannot tell which is which. Knowing the names helps when you describe a problem on the phone and when you read a manual. This glossary groups the parts by what they do, explains each in plain language and points to the page that covers repairs.
A safety note: the springs, cables, drums and bottom brackets hold stored tension even when the door is closed. Look, but do not touch them.
The Door Itself
| Part | What it is | Read more |
|---|---|---|
| Section or panel | One of the horizontal slabs the door is made of | Panel repair |
| Strut | A stiffener across the back of a wide section | Panel repair |
| Hinge | Joins two sections and holds a roller | Roller replacement |
| Roller | The wheel that rides inside the track | Roller replacement |
| Bottom seal | The rubber strip on the bottom edge | Seal replacement |
| Weatherstripping (stop molding) | The strips along the sides and top of the opening | Water under the door |
| Bottom bracket | The fixture at each bottom corner that anchors the lift cable. It is under tension | Cable repair |
Springs and the Lift System
| Part | What it is | Read more |
|---|---|---|
| Torsion spring | A wound coil on a shaft above the door that carries most of its weight | Torsion springs |
| Extension spring | A long spring along the side track that stretches as the door closes | Extension springs |
| Safety cable | The cable through the middle of an extension spring that contains it if it breaks | Extension springs |
| Shaft or torsion tube | The steel bar the torsion springs and drums sit on | Torsion springs |
| Center bearing plate | The bracket in the middle of the shaft that holds it up | Torsion springs |
| Winding cone | The end of the torsion spring where it is wound and locked. It is under tension | Spring safety |
| Cable drum | The grooved wheel at each end of the shaft that winds the lift cable | Cable repair |
| Lift cable | The cable that connects the bottom bracket to the drum | Cable repair |
Tracks and Frame
| Part | What it is | Read more |
|---|---|---|
| Vertical track | The track that runs up each side of the opening | Off-track repair |
| Horizontal track | The track that runs back along the ceiling | Off-track repair |
| Curved section | The bend where the vertical track meets the horizontal | Off-track repair |
| Track bracket | The fixture that holds the track to the wall or ceiling | Off-track repair |
| Jamb and header | The framing on each side of, and above, the opening | Measuring guide |
The Opener and Controls
| Part | What it is | Read more |
|---|---|---|
| Motor unit (powerhead) | The housing on the ceiling with the motor and the logic board | Opener repair |
| Rail | The track the trolley rides along | Opener installation |
| Trolley (carriage) | The part that rides the rail and connects to the door arm | Manual opening guide |
| Chain, belt or screw | The drive that moves the trolley along the rail | Opener installation |
| Emergency release cord (red cord) | The cord that disconnects the door from the opener | Manual opening guide |
| Photo eyes (safety sensors) | The two units near the floor that watch for obstructions | Sensor repair |
| Wall control | The button panel on the wall inside the garage | Remote and keypad repair |
| Limit and force settings | The adjustments that decide where the door stops and how hard the opener pushes | Won’t-close guide |
Parts That Hold Tension: A Quick Reference
These parts stay under load even when the door is closed. Look, but leave them to a technician.
- The springs, both torsion and extension
- The winding cones and set screws on a torsion spring
- The lift cables
- The cable drums
- The bottom brackets at each lower corner
Our guide to what you can fix yourself explains which jobs are safe, and the spring safety guide explains why these are not.
Related Services and Guides
Frequently Asked Questions
What is the red cord hanging from my garage door opener?
The emergency release cord. Pulling it disconnects the door from the opener so the door can be moved by hand. Use it only with the door fully closed.
What is the cable running through the long spring?
A safety cable. On an extension spring it contains the spring if it breaks, so that the spring does not whip across the garage.
What is the metal plate in the middle of the spring shaft?
The center bearing plate, which supports the shaft and the springs.
What are the bars across the back of the door?
Struts. They stiffen wide sections so the door does not flex.
Not sure what part is broken?
Tell us what you see and where, and we will tell you what it is and how soon we can be there.
Elite Miami Gardens Garage Door Repair, 6187 NW 167th St, Suite 101, Miami Gardens, FL 33015