Most Doors We Tune Up Have Already Been Sprayed

Rollers roll along the track. They do not slide. Putting grease in the channel reduces no friction because there is no sliding contact there to reduce, and what it does instead is trap grit until the mixture behaves more like a lapping compound than a lubricant. The rollers then skid through it, develop flat spots, and the door ends up louder than it was before anybody touched it.

Track gets cleaned rather than lubricated. A rag run down the inside of the channel, top to bottom, taking off the black paste that builds from old spray and worn roller material. On a door sprayed every spring for a decade, cleaning the track out is on its own a noticeable change.

The boundary is worth knowing, because plenty of people spray a door over and over hoping to reach something spray cannot. A squeal or a chirp is dry metal and it does respond. A deep rumble that fills the room is roller bearings that have broken down internally, and no lubricant gets inside a sealed one. One bang at a fixed point in the travel is normally a loose hinge or bracket.

A door that groans as it rises and feels heavy in the hand has a counterbalance problem, and no lubricant does anything for a spring that has given up its tension. A door that catches at exactly the same height every cycle has track or bracket geometry sitting wrong. If the quiet lasted a fortnight after the last spray, the noise was never about lubrication in the first place.