Doors from this era were built with 7-ball nylon rollers as the default, not steel ball-bearing units, because nylon was quieter and cheap to spec at scale across new subdivisions. Nylon holds up fine in moderate weather but gets brittle with age and cold-weather flexing, and this area sits in a cold-severe climate band - the freeze-thaw cycle each winter is exactly what cracks a stem that's already thirty-some years into its service life. The failure usually shows up the same way: a grinding or slapping noise on the second or third roller back from the bottom, worse on cold mornings when the nylon has contracted and the gap in the track roughens up. Owners often blame the opener first. It's rarely the opener. It's the roller stem, and by the time it's loud enough to notice, the track edge near that roller is usually scored too, which is the part that turns a $20 roller into a track-section repair if it sits too long.