Why Is My Garage Door Uneven on One Side?
A garage door that hangs lower on one side than the other — visibly tilted or crooked when you look at it from the driveway — is almost always caused by a broken or worn cable on the lower side, a spring that has lost tension, or (less commonly) a bent track that is causing one side to hang at a different height.
The door is counterbalanced by two cables (one on each side) wound around drums at the top of the tracks, which are in turn held under tension by the torsion spring(s) above the door. When one cable breaks, frays, or falls off the drum, that side of the door drops — creating the visible tilt. When a spring loses tension on one side (more common with dual-spring setups than single torsion), one side gets progressively less support and the door gradually becomes uneven over weeks or months.
Do not continue to operate the door. Running a door that is out of balance puts severe asymmetric stress on the opener motor and trolley, can cause the door to jump off its tracks, and risks panel damage or sudden failure. Stop using the opener until a technician inspects it.
Cause #1 — Broken or Derailed Cable (Most Common)
The lift cables run from the bottom brackets on each side of the door up and around the cable drums at the top of each vertical track. They're typically 1/8" galvanized steel wire rated for thousands of pounds. But after 8-15 years of daily cycling in Pennsylvania's humidity and temperature swings, the cable strands fray from the inside, the fraying accelerates, and eventually one strand breaks at a time until the cable snaps or derails from the drum.
When a cable breaks on the right side: the right side of the door drops. The left side stays at the correct height. The door looks like it's sinking on one corner. The opener may still try to run — do not let it. Running an opener against an off-balance door can strip the gear in a single session.
Cable on drum: Sometimes the cable doesn't break — it slips off the drum. Symptom is the same (one side drops) but the fix is faster (resetting and retensioning the cable). Still requires a technician because the spring will need to be wound down, cable reset, and drum retensioned — all under spring tension.
Cost in PA: Cable pair replacement quoted in person including drums and hardware inspection.
Cause #2 — Spring Tension Loss or Failure
Modern residential garage doors typically use either a single torsion spring centered above the door or a pair of torsion springs. With a single spring, if it fails fully, the door won't open at all — not the "uneven" scenario. But with dual springs (or a partially failed single spring that's lost coil tension gradually), one side can lose counterbalance support and sag lower than the other.
Extension springs — the type mounted on cables running parallel to the horizontal track sections — are more common in older PA homes (pre-1995). When one extension spring breaks, it creates immediate and dramatic asymmetry. The door drops on the broken-spring side and the cable on that side goes completely slack. This is a same-day emergency.
Cost in PA: Spring pair replacement (torsion) quoted in person Extension spring pair quoted in person Recommended to replace in pairs — if one is at failure, the other is within weeks.
Cause #3 — Bent or Misaligned Track
If both cables and springs are intact but the door still hangs unevenly, a track may be bent or pulled out of vertical alignment. This is less common than cable/spring issues but happens after vehicle impacts (a car or snowblower bumped the track), settling foundations shifting the door frame, or hardware vibrating loose over years of operation.
Symptom: The door hangs unevenly only at one specific point in its travel — level when fully closed, uneven when partially open, and levels out again near the top. That indicates a local track deformation rather than cable/spring asymmetry, which would affect the full travel range.
Cost in PA: Track realignment quoted in person Full track section replacement quoted in person
Cause #4 — Bottom Bracket Failure
The bottom bracket connects the cable to the bottom corner of the door. After many years of operation, this bracket can crack, deform, or pull away from the door panel — dropping that corner of the door independent of the cable itself. Symptom: the cable looks intact but one corner of the door is lower. Look at the bottom corner of the door for a bracket that's bent, cracked, or not flush with the door surface.
This is fixable — bottom bracket replacement is quoted in person per side — but requires releasing spring tension safely to replace. Not a DIY repair.
Why You Should Not Try to Fix This Yourself
Garage door cables and springs are under extreme tension even when the door is in the closed position. A torsion spring on a standard 7-foot residential door stores -800 foot-pounds of energy when fully wound. Releasing that energy in an uncontrolled way — which is what happens when an untrained person attempts to adjust spring tension or replace a cable — can cause the spring to unwind violently, send hardware flying at high velocity, or cause the door to drop suddenly on anyone beneath it.
Every year in Pennsylvania, homeowners are seriously injured attempting DIY spring and cable work. We see the aftermath when we're called to fix damage from a collapsed door: bent tracks, destroyed panels, and in some cases structural damage to the door frame. The repair cost after a DIY attempt gone wrong is typically 3-5x what a professional repair would have cost. Call a technician. This is not the category of garage door work where DIY saves money.
How OnPoint Diagnoses and Fixes an Uneven Door
When we arrive for an uneven door call in Pennsylvania, the diagnostic process takes 5-10 minutes. The technician will.
- Visually inspect both cables (looking for fraying, slack, or drum derailment)
- Inspect both springs for visible breaks, gaps in the coil, or uneven tension
- Check the bottom brackets on both sides
- Measure the door gap at the floor across the full width
- Run a balance test (briefly disconnect the opener and manually lift the door — a balanced door stays put at any height; an unbalanced door drops or rises)
After diagnosis: written estimate, your approval, then repair. Most uneven door calls in PA are resolved in 45-90 minutes in a single visit. We carry cable pairs, spring sets, drums, and brackets on every service truck.
Free Estimate — No Charge for the Visit
We quote every job in person, free, with no obligation. The diagnostic visit is free and there is no trip fee. Call (484) 312-5999 to book a time that works for you.
All prices include PA labor, parts, 5-year workmanship warranty. Free diagnostic. No trip fee. Written estimate before work begins.
Pennsylvania Climate and Uneven Door Frequency
Cable failures spike in Pennsylvania during two seasonal windows: late winter / early spring (when cables that have been corroding under salt and road spray moisture since November finally lose the last of their structural integrity) and midsummer (when the combination of heat expansion and humidity-accelerated corrosion pushes marginal cables to failure). In Pittsburgh's hillside neighborhoods, cable fatigue is more common than average because the steep driveway approach means the door operates at higher cable tension loads — the door weight vectors differently on a steep slope.
If your cables are original equipment on a door installed more than 8-10 years ago in PA, an annual tune-up inspection (quoted in person) is the most cost-effective way to catch fraying before it becomes an emergency. We check cable condition as part of every tune-up and will flag cables that show early fraying.