Why is my garage door uneven or crooked when it closes?

A garage door that lowers at an angle, with one side dropping further than the other, is not just an aesthetic problem. It signals a real mechanical imbalance, and continuing to operate it in that state puts extra stress on the opener, cables, tracks, and spring system. The fix depends on the cause, but identifying the cause is usually straightforward.

Broken or stretched cable on one side

The most common reason a door closes crooked is a problem with one of the lift cables. Each side of the door has a cable that runs from a drum above the door, down the track, and attaches to the bottom bracket of the door. The cable on each side carries equal share of the door's weight as it opens and closes.

When one cable breaks or comes off the drum, that side of the door has no lift support. It drops lower. The door descends at an angle, with the problem side going further down than the other. In some cases, the cable does not break entirely: it may stretch unevenly, or the cable end may slip from the bottom bracket.

Look at both sides of the door from the inside. Are both cables taut and running straight from the bottom bracket up to the drum? A cable that hangs loosely on one side, or is entirely absent from the bracket, is the cause.

Symptom	Likely cause	Action
Door drops lower on one side	Broken or slack cable on low side	Technician cable replacement
Door is tilted and jerks during travel	Cable off drum on one side	Technician cable re-seat and inspect
Door binds then tilts	Track misalignment on one side	Track adjustment
New crookedness after a loud bang	Broken spring	Technician spring replacement

Spring imbalance on extension spring systems

Homes with extension springs (springs that run horizontally along the track, one per side) can develop uneven door closing when one spring wears out faster than the other. As one spring loses tension, it no longer provides the same lift force as the other side. The door pulls down on the weaker side.

This is different from a broken spring. A single broken extension spring is usually obvious (it hangs loose or is clearly snapped). A worn spring that has lost tension over time may still look intact but is providing 10 to 20 percent less force than the new side. The result is a gradual tilt that gets worse over time.

The standard advice from spring manufacturers, including DASMA, is to replace extension springs in matched pairs. When one spring wears out, the other is close behind. Replacing only the broken spring leaves an imbalance between a new spring and an aging one. The door may close slightly crooked even after the repair.

Track alignment as a cause

A vertical track that is not plumb (perfectly vertical) causes the roller on that side to travel on a slightly different path than the other side. This can make the door appear to close unevenly.

Use a level on the inside face of each vertical track. The track should be plumb from top to bottom. If one track leans inward or outward relative to the other, the door will tilt as it closes. Track misalignment may also cause the door to rub against the stop molding on one side, leaving paint or finish marks on the door edge.

Correcting track alignment involves loosening the track brackets, repositioning the track to plumb, and retightening. If the bracket bolts have stripped the wall anchors, the anchors need to be replaced before the track can be properly secured.

When is it safe to keep using the door?

A door that closes slightly unevenly but still seats fully against the floor seal on both sides and operates without noise or jerking may be monitored for a short period while you schedule service. A door that bangs, jumps, drops suddenly on one side, or leaves a significant gap at the bottom is not safe to continue using in that state.

In Denver and along the Front Range, many homes have older garage doors where springs and cables have seen 10 to 15 years of use. A small tilt that appears in October may worsen significantly through the winter as cold weather affects spring tension. Addressing it before hard winter weather sets in avoids a failure on a cold morning when you need the door to work.

Do not attempt to adjust spring tension or re-seat cables yourself. Cable and spring systems are under high tension, and improper handling causes serious injury. G Brothers can typically diagnose and repair uneven door problems the same day.

What an uneven door does long-term and how repairs work

An uncorrected tilt does more than look bad. The door exerts uneven force on the opener trolley, wearing the carriage assembly faster on the heavy side. The off-angle load stresses track brackets on the lower side, eventually loosening them from the wall.

The photo-eye sensors can also be affected. If the door descends at an angle, the bottom edge may approach sensor brackets from an angle, increasing the risk of false triggering or light contact with a sensor before fully closing. Over time, uneven load also accelerates hinge wear on the heavier side.

A technician starts a repair by checking cable tension on both sides. Cables should be equally taut when the door is in the closed position. On extension spring systems, the springs on each side are compared for equal tension. If a cable is the problem, it gets replaced. If a spring is worn unequally, both springs are replaced as a matched pair, which is the standard practice recommended by spring manufacturers including DASMA. Track alignment is checked after the spring and cable work, because a track problem may only show up after spring tension is corrected.

After repairs, the technician runs the door through several cycles and checks the bottom edge alignment before calling the job complete.

For homeowners in older Denver homes with extension spring systems, it is worth asking whether a conversion to a torsion spring system makes sense at the same time as the cable replacement. Torsion springs above the door provide more consistent, balanced tension than paired extension springs. They are generally longer-lasting and are easier to service because all the tension hardware is in one location above the door rather than distributed along the tracks. A torsion conversion is a bigger job than a cable replacement alone, but it can make sense to do both at the same time when major spring or cable work is already underway.

If the door has been closing unevenly for a while before you noticed it, also inspect the bottom weather seal and the track brackets on the lower side for signs of extra wear. The uneven load may have accelerated wear on components that would not normally need replacement for another few years. Catching this early keeps the total repair bill lower. A door that has been operating unevenly for six months or more may need track bracket re-anchoring in addition to the spring or cable repair, because the repeated off-angle load works bracket bolts loose over time.

G Brothers Garage Doors serves the Denver metro and Front Range with free estimates, same-day service on cable and spring repairs, and 24/7 emergency response. Licensed and insured.