This area sits in a cold, severe climate band, and that's hard on any door, but it's harder on hardware that's already 60-plus years old. Steel that's cycled through decades of freeze and thaw gets brittle at the spring coils first - that's where we see the snap, usually on a cold morning when the door's asked to lift a weight it handled fine the day before. Extension springs common on Zilwaukee's older stock lose tension unevenly, so one side gives out while the other still looks fine, which throws the door off its track on the next open. Track brackets fastened to jamb wood that's shrunk and re-swelled for six decades work loose the same way. We also see rollers seized from lack of lubrication over a winter, which binds the door hard enough that an opener will strip its gear trying to force it rather than stop.