The Warning Signs
The homeowner in this West Loop condo building had been hearing a faint grinding sound for almost three weeks — always when the door was going up, never coming down. That’s a specific pattern: it points to the cable making contact with something during the wind-up sequence. She called before it snapped, which put her in a much better position than most of the cable calls we get.
What We Found
The left lift cable had seven broken wire strands at the bottom bracket — the highest-stress point in the cable system, where the cable bends around the pulley before heading to the drum. Wire failures always start here first, because the wrap angle concentrates fatigue. The right cable looked clean from the ground, but closer inspection at the drum revealed early kinking in the layering — the beginning of the same failure on the other side. In these cases, we always replace both: matched cables wear at the same rate, and replacing one puts unequal tension on the door that accelerates the remaining cable’s failure.
Both cables were replaced with 7×19 stainless aircraft-grade wire, rated to 2,200 lbs each on a 218-lb door. The drums were cleaned of built-up debris, the center bearing and end bearings were lubricated, and the spring tension was checked and confirmed in balance before we left. The grinding that had been building for three weeks was gone on the first cycle after the repair.