Maintenance tunes up garage doors. It makes their movement smoother, quiets down noises and fixes problems. Maintenance doesn't take place due to specific problems. It's instead a preventive service so that garage door parts will operate properly and free of problems. It's one way to prevent problems from ever emerging and when garage doors operate properly, they are safe. During the service all parts are inspected, obvious problems are repaired and steel components are lubricated.
When parts are tightened, cleaned, adjusted, repaired and lubricated, it is hardly unlikely to cause problems in the near future. Stability is ensured and the garage door is rejuvenated. It is tuned up. That's why it is said that garage doors look as good as new after maintenance. They are actually restored and gain back a fresher look. Although it looks good, the service is not done for appearances but to prolong the lifespan of the whole system, and ensure both great performance and safety.