Maintenance
Garage Door Lock Bars Explained
The lock bar is the simple steel rod that slides into the track and stops your door being lifted. Here's how it works and what to do when it seizes.
What a lock bar does
On manually operated roller and tilt doors, a spring-loaded bar slides sideways into a slot in the track. With the bar engaged the door physically can't travel, which is why it's still one of the most effective anti-lift measures on an older door.
Why lock bars jam
Nine times out of ten the bar is fine and the door has simply dropped a few millimetres, so the bar no longer lines up with the slot in the track. Rust, a bent track or a stretched spring will all cause this.
Fixing a seized lock bar
Give the bar a spray of dry lubricant, then lift the door slightly by hand while sliding the bar. If it still won't budge, don't force it — a bent bar can jam the door permanently. That's a five-minute job for a tech with the right gear.
Published 10 February 2026 · 5 min read · Impact Doors
Frequently Asked Questions
- Should I keep the lock bar if I have an automatic opener?
- No — engaging a lock bar with a motorised door will damage the opener. Most techs remove or permanently disengage the bar when fitting an opener.