Garage Door Cable Replacement: preparing for the visit

The cable has wrapped itself around the shaft above the door instead of sitting on its drum. When the opener runs, the door lurches, one side rises before the other, and the top panel twists.

Worth answering before the call

Does the opener still run, and does it strain or reverse? Is anything stored close to the door or under the spring shaft? Is there a car inside that you need out before the visit?

Should both cables be replaced when only one has failed?

Yes, as a rule. The two cables were fitted together, have flexed around their drums the same number of times and have sat in the same slush, so the survivor is close to the end of its life. A new cable beside a stretched one also makes it harder to set the door level. Two matched cables give an even lift and one visit instead of two.

How do I tell a cable problem from a spring problem?

Look above the door with it closed. A torsion spring that has broken shows a clear gap in the coil, and both cables usually go slack together because nothing is turning the shaft. A cable problem tends to show on one side only: a frayed length, a coil of loose cable, or one corner sitting higher. Either way the technician inspects both, since a weak spring is a common reason a cable fails.