The rollers are probably the most important part of the functions of a garage door because like a car or motorcycle they don’t go anywhere without the basic invention of the wheel. A garage door can function with broken springs and bent track or bent panels or even broken hinges but it absolutely does not work properly without a good set of rollers.  When rollers have not been lubed properly and have attracted a lot of dirt and debris typically in windy areas like desert or dry dusty regions. This happens when doors in these elements are left open for long periods of time the rollers attract the sand and dirt blowing around in an open garage. Especially if the rollers are lubed with heavy grease.

dirt and sand had built up

I once made a service call to a desert community in Southern California and the homeowner had a garage that was open on one side it only had three walls kind of like a carport. The dirt and sand had built up on the rollers so bad that the door would not even move when I tried to lift it by hand.  Broken or worn out rollers can cause the door to fall down into your garage damaging cars and items in the garage. The rollers hold the entire weight of the door when it is open. And when they wear down and the wheel gets smaller they pop out of the track and causes all kinds of problems with the door.

The most damaging roller failure will happen with the very top or bottom rollers

The top roller because when the top rollers pop out of track the top of door comes down when you open the door. And the bottom roller is attached to the spring assist assembly and causes a whole set of other problems. I have seen doors still function when a roller in between the top and bottom rollers has come out of the track. It might not open or close very smooth but some homeowners don’t even realize there is a major problem with the door because it goes up and down when they push the buttons. Homeowners need to pay attention to their garage door like they pay attention to the front door when they leave their home and make sure it is closed and locked.