With a median build year of 1980, West Chicago's garage doors are old enough that steel rollers have logged four decades of Illinois winters without much room for anything to fail gracefully. This area sits in the same cold, moderate climate band as the rest of the region we work in - freeze-thaw cycles that swell and shrink the track brackets against the framing, which is slow, steady wear rather than one bad storm. On a door that age the rollers are almost never nylon; nylon rollers only became common on later replacements, so what's up there now is the original steel, or close to it. Steel rollers don't flex the way nylon does, so they transmit every bit of track misalignment straight into the stem and the bearing, and that's usually where the grinding noise starts. None of this is unique to one house - it's the housing stock talking, not bad luck.