Extension spring wear
Extension springs run along the horizontal tracks instead of overhead on a shaft, and they wear differently - the coils stretch, the safety cables (if they were ever added) fray, and the pulleys seize before anything else fails. We carry replacement extension springs sized to the older 7-foot and 16-foot door openings common in this build era, along with the galvanized lift cables, pulleys, and stop-plates that go with that hardware.
