Garage door off track: getting it back on and safe

A door comes off its track when a roller leaves the channel it runs in. Sometimes that is one roller at the top and the door still looks nearly straight. Sometimes the whole side has come out and the door is hanging in the opening at an angle.

Either way, the first thing to do is stop. Do not press the opener button, and pull the red emergency release cord so the opener is disconnected from the door. Every additional cycle drags the door further out of line and turns a roller job into a bent track and creased sections.

If the door dropped or nearly hit someone, Health Canada takes incident reports on consumer products from anyone, near misses and property damage included. It asks what happened and when, what the product is and where it came from, and for photos of the product and its labels, so take them before you move anything.

What actually causes it

A vehicle touching the door is the obvious one, and it usually bends the track as well as popping the roller. Worn rollers are the common one: a steel roller with a failed bearing stops rolling and starts sliding, and a slider eventually climbs out. After that it is loose track brackets, which let the track flex until the roller has room to escape, and debris or ice in the bottom of the channel.

The cable is the one people miss. If a cable slips off its drum, one side of the door is no longer being held up, that corner drops, and the rollers on that side come out because the door is no longer square. The roller is the symptom; the drum is the fault.

Why the internet advice is risky here

There is a lot of video showing a roller being levered back in with a pair of pliers. On a door that is fully up, on one top roller, with the cables tight and the track undamaged, that is roughly what happens. The reason it goes wrong is everything around it: the bottom bracket is under cable tension and is not something to unbolt, a door held only by an opener rail can drop, and a track that has been sprung will let the roller straight back out.

What we do

The door gets clamped so it cannot move, the tension comes off in a controlled way, and the door is lifted back into the track. Then the actual cause is dealt with: the track is straightened or replaced, the drums are re-spooled and the cables reset to equal length, worn rollers are changed, brackets are tightened, and the door is run and rebalanced before the opener is reconnected.

Sections are inspected at the same time. A door that has been forced while off-track often has a crease or a pulled hinge that will put it back on the floor in a month if nobody looks for it.