Why is the garage door crooked?

A garage door becomes crooked, meaning one side is higher than the other or it closes at an angle, due to several mechanical failures that cause uneven lifting and imbalance. The most common cause is a broken or loose cable on one side; cables wrap around drums above the door on torsion systems or run through pulleys on extension systems, and if one cable frays, snaps, or comes off its drum, that side loses tension and lags, making door crooked. A broken torsion spring on a two-spring system causes similar crookedness because only one spring provides lift, making door heavy on broken side. Loose or bent vertical tracks cause rollers to bind on one side, causing uneven movement and crooked appearance when closing. Worn or damaged rollers that are cracked or seized can cause one side to drag. An unbalanced door due to incorrect spring tension, where springs have different tension levels, pulls unevenly. Impact damage from car hitting door bends tracks and panels, causing crooked travel. Foundation settling can shift track mounting points out of plumb. Lack of maintenance like not lubricating rollers causes binding. Even small issues like debris in one track cause drag. To diagnose, disconnect opener via emergency release and manually lift door to see which side is heavy or binding. Professional inspection costing 75 to 150 dollars can pinpoint cause, and repairs range from 150 to 600 dollars depending on cables, springs, or tracks.