The tell is a rhythmic clunk or grind as the door travels - one bump per roller, at the same point in the cycle every time, rather than a random rattle. On a 1973-era door with steel rollers, that sound usually means a bearing's gone dry inside the roller stem. Given this area's cold-moderate climate, that dry bearing seizes up faster in winter, which is when a lot of these calls come in.
If you're hearing it only on the way down, or only near the top, that's usually one specific roller rather than the whole set - worth mentioning when you call, since it changes what we bring on the truck.