A worn nylon roller starts as noise, a rhythmic thump as the door travels, but it doesn't stop there. Once the nylon sleeve wears thin, the steel stem starts riding directly against the track, which chews a groove into aluminum track over a few months. Keep running it and the roller can jump the track entirely, usually on the top section where the angle changes, and that's a stuck door with an off-track panel, not a simple part swap anymore. On the newer sectional doors common in Maple Valley, we also see roller brackets loosen slightly as the door settles over 20+ years, which lets the roller wobble even when the roller itself is fine. Diagnosing which one you actually have matters, because tightening a bracket costs a fraction of replacing a full roller set.