Roller Replacement for SeaTac's Early-70s Garage Doors

On a door built when SeaTac's houses went up, the roller is steel, the track is steel, and there's no bearing seal between them. That combination wears in one specific way: the roller flat-spots on one side, then starts riding up the edge of the track instead of straight through it. You hear it before you see it - a grinding tick on every rotation that gets louder as the flat spot widens. Left alone, the roller stem works loose in the hinge and eventually snaps off mid-cycle, usually with the door half open.

SeaTac's housing stock centers on a 1971 median build year, which puts a lot of doors here a good decade ahead of the newer stock further out in the service area, where the median build lands closer to 1984. That gap matters for rollers specifically - older track tends to be narrower gauge and mounted with fewer brackets per side, so a worn roller has more room to wander before it jumps the track entirely. It's not a dramatic failure until it is, and then it's a Saturday morning with the car stuck inside.