Garage Door Is Crooked or Hanging on One Side

You noticed it from the driveway: the bottom edge isn't parallel to the concrete any more. One corner is up, the other is down, and the door looks like it's being pulled sideways into the opening.

What that means is simple to state and important to get right. The two bottom corners of a sectional door are lifted by two separate cables, and those cables have to release and take up in step with each other. When one takes up faster than the other, the door climbs unevenly. The tilt is the readout.

Before anything else, one correction, because the internet gets it wrong constantly: a crooked door is not caused by one of two springs breaking. Both springs on a torsion setup sit on the same shaft. They turn together. If one lets go, the whole door gets heavy at once — evenly. It does not sag at one end. The tilt is a cable, a drum, or something on one side of the door binding.

High risk — leave this to a technician Involves high-tension components or the door’s full weight. This is where people get badly hurt.

This is general guidance based on what we see on service calls — it isn’t a substitute for someone looking at your actual door. Every door is a little different, and if anything here feels beyond what you want to take on, stop and give us a call.

How urgent this is

Stop cycling the door now — including the one last test to see how bad it is. A tilt of an inch or two at the bottom edge is enough to be worth stopping over, and a tilt you can see from across the street is well past that.

A tilted door is running its rollers at an angle inside a channel built for them to run straight. Each cycle drives the wheels against the track lip, works the hinge fixings, and lets the loose cable wander further across its drum. This is the last quiet stage before something loud happens.

Leave the door wherever it currently is — a tilted door that's down is fine to leave down, and one that's up is safer left up than brought down uncontrolled. Unplug the opener so nobody can operate it, park outside, and keep the opening clear. If the door has also come out of its rails, mention it, since that turns the visit into an off-track garage door repair.

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What to check in the next 10 minutes

Four observations from outside the opening. They separate a door that's tilted from a door that's merely sitting on an uneven floor, which is a completely different and much smaller problem.

  1. 1
    Watch the bottom edge through a full open, from outside

    Not from inside where the light is behind it. Stand in the driveway and watch the bottom edge against the concrete as the door rises. A door that starts level and goes out of square as it climbs is a live cable or drum problem. A door that's out of square from the first inch is more likely a track or bracket that has moved.

    You’ll know it worked when: You can say whether the tilt appears during travel or exists at rest.

  2. 2
    Look at both cables where they meet the drums

    The drums sit at each end of the shaft above the opening. On a healthy door the cable winds into its grooves in a neat single layer. You're looking for one that's slack, riding over the top of itself, sitting outside its grooves, or bunched near one end of the drum.

    You’ll know it worked when: You've compared the left drum against the right, rather than just looked at one.

  3. 3
    Look at the spring coil above the door

    A break shows as an obvious gap, like a piece has been removed. Note it if you see it — but note also that a break makes the door uniformly heavy rather than one-sided. Finding a gap tells you why the door is being forced, not why it's tilted.

    You’ll know it worked when: You know whether the counterbalance is intact.

  4. 4
    Check whether one side is being held back

    Look down both vertical tracks and along both sides of the door for something physically restraining one end — a slide lock partly thrown, a shelf bracket in the path, a roller that has jammed, a hinge that has come apart, or an object leaning against the door on one side.

    You’ll know it worked when: You've ruled a physical obstruction in or out on both sides.

Is the door tilted, or is the floor?

This one question separates an urgent mechanical fault from a cosmetic annoyance, and plenty of people call us about the second thinking it's the first.

Does the door hang square while it moves and only show a gap when it's fully closed — or is it out of square throughout its travel?
It runs square, and only the closed gap is uneven
What that means: The door is fine. What's uneven is the concrete underneath it, which in this valley is common enough to be unremarkable — slabs are poured with drainage in mind and plenty of them settle afterwards. That's a sealing question, not a counterbalance one.
Where to go next: Nothing on this page applies. Look at the slab and seal instead.
It's out of square while it's moving
What that means: The two sides are not sharing the load. Something on the lifting system has changed — a cable, a drum, a drum set screw, or a bind that one side is fighting. That's what the rest of this page is about, and it's genuinely time-sensitive.
Where to go next: Work through causes 1 to 6.
It got worse over the course of a week or two
What that means: A progressive tilt is a cable slowly migrating across its drum, or a drum creeping on the shaft. That progression has an end point, and the end point is the cable coming off entirely.
Where to go next: Causes 1 and 2 in particular.

The cheap diagnostic is a tape measure: bottom edge to floor at the left end, then at the right end, with the door most of the way down. More than about an inch of difference is a door out of square rather than a floor out of level.

Which version of crooked is it?

The specific pattern narrows the cause considerably.

Goes up level, comes down crooked

One cable is unwinding faster than the other — usually spooling problems on a drum.

Jump to that fix ↓
Gets progressively more crooked the higher it goes

The classic signature of a cable riding out of its grooves or a drum slipping on the shaft.

Jump to that fix ↓
Tilted from the first inch of travel

Something is physically holding one side down — a lock, a jammed roller, a broken hinge, an obstruction.

Jump to that fix ↓
Went crooked immediately after a bang from the garage

The counterbalance failed and the door has been driven by the opener since, which loads it unevenly.

Jump to that fix ↓
Corner drooping with a visibly slack cable

That side isn't being carried at all. This is the state just before an off-track event.

Jump to that fix ↓
Only crooked when it's fully closed, square otherwise

Not a door problem. The floor is uneven or the seal has compressed unevenly.

Jump to that fix ↓
Top section leaning while the lower sections look square

A top roller bracket has shifted or a hinge at the top has failed. Different fix, same urgency.

Jump to that fix ↓

Why two sides have to move as one — and why it isn't one spring

Above the opening runs a steel shaft. The springs are mounted on it, and so is a grooved drum at each end. A cable runs from each drum down to a bracket at the bottom corner of the door. When the shaft turns, both drums turn with it, both cables wind on together, and both corners rise together. That's the entire lifting system.

Now the correction that matters. On a door with two torsion springs, both springs sit on that same single shaft. They are not independent — they can't be. Turn one end of the shaft and the other end turns too. So when a spring breaks, the door doesn't sag at that end; it simply loses roughly half its counterbalance everywhere at once and gets heavy across the whole width. If you have read that a lopsided door means one spring went, that is the thing to unlearn. It comes up in almost every conversation we have about this symptom.

What genuinely produces a tilt is a difference between the two cables. If the left cable is winding onto a drum in a neat helix and the right cable has climbed over the top of its own wraps, the right side is now effectively on a larger diameter and takes up more cable per turn of the shaft. That corner rises faster. Reverse it and it rises slower. Either way the door skews.

The other route is a drum that has slipped on the shaft. Each drum is held by set screws bearing on the shaft. If those loosen, the drum can rotate relative to the shaft, effectively paying out cable on one side while the other holds. That produces a tilt that gets worse in one direction, cycle after cycle.

And the third route is a bind: one side of the door held back by a jammed roller, a failed hinge, a lock, or an obstruction. The shaft still turns evenly, but one corner physically can't follow, so the sections rack and the door goes out of square.

Cable drum The grooved wheel at each end of the shaft that the lift cable winds onto. The grooves are what keep the cable in a single layer.
Effective diameter How far out from the shaft the cable is sitting. A cable riding over its own wraps has a larger effective diameter and lifts that corner faster.
One shaft Both torsion springs and both drums share a single shaft. They cannot act independently, which is why a broken spring makes a door heavy rather than lopsided.
Racking Sections twisting against each other because the two ends of the door are at different heights. What damages hinges and end stiles.

So the reading is: even tilt during travel means the two cables are no longer in step, and a door held back on one side means something physical is stopping that corner. Neither is a spring failing on its own.

Matching the pattern to the cause

The way the tilt behaves tells you a great deal. Find the closest row.

What you’re seeingMost likely causeHow urgentWho should fix it
Tilt increases the higher the door goesA cable riding out of its drum grooves and lifting on a bigger effective diameterStop using itCall a pro
Tilt has gotten worse week by weekDrum creeping on the shaft as the set screws lose their gripStop using itCall a pro
One cable visibly slack, that corner droopingThat side has lost support entirely — the cable is off or has come loose at a fixingStop using itCall a pro
Door is heavy AND crooked, spring shows a gapCounterbalance failed; the opener has been lifting from one center point and racking the doorStop using itCall a pro
Out of square from the very first inch of travelOne side physically restrained — a slide lock, a jammed roller, a failed hingeStop using itCall a pro
Top of the door leaning, bottom sections squareTop roller bracket shifted or top hinge failureFix todayCall a pro
Appeared right after the door hit somethingImpact moved a track or bracket, so one side now runs on a different lineStop using itCall a pro
Square through travel, uneven gap only when closedUneven slab or a compressed seal — not a lifting fault at allFix this monthEither — call us if unsure
Door binds and shudders on the same side each timeVertical track out of plumb on that side, often from a loosened bracketFix todayCall a pro
Grinding or popping noise accompanying the tiltRollers being driven into the track lip by the skewStop using itCall a pro

What’s actually causing it

These are ordered the way we work through them on a real service call — cheapest and most common first, so you don’t start by replacing a part that was never the problem.

1

A cable has climbed out of its drum grooves

High risk — call a technician

The most common cause and the most reliably misread one. The drum is grooved so the cable lays in a single neat helix, each wrap sitting beside the last rather than on top of it. If the cable ever goes slack while the drum keeps turning — which happens if the door touches down early, hits an obstruction on the way down, or is pushed down by hand faster than the shaft unwinds — the cable can jump a groove and start wrapping over itself.

From that moment, that corner is being lifted on a larger effective radius. It rises faster than the other. The door goes up progressively more out of square, and the further it goes the worse it gets.

The reason this is urgent rather than annoying: a cable wrapped over itself gets crushed between its own wraps under load. That damages the strands, and a damaged cable is a cable heading for a failure of its own.

How you can tell: The tilt grows as the door rises and is worst at full open. Looking up at the drum, the cable is stacked over itself rather than sitting in single-file grooves.

Where to stop: Don't try to lift the cable back into its grooves, and don't rotate the shaft to unwind it. The cable is carrying the door's weight under full spring tension while it looks slack, and slack cable under a wound spring is exactly the thing that moves suddenly.
2

A cable drum has slipped on the shaft

High risk — call a technician

Each drum is clamped to the shaft by set screws that bite into it. Those screws only need to slip a fraction for the door to lose its symmetry, because a drum that rotates relative to the shaft has effectively paid out cable on that side without the other side doing the same.

Set screws let go for ordinary reasons: they were never fully torqued at installation, the shaft has a flattened or burred spot where they've been sitting, or years of daily heat cycling in a Mesa garage have worked them looser. Once one starts creeping, it creeps a little more every cycle, which is why this version of the symptom gets steadily worse rather than appearing overnight.

What makes it different from cause 1: the cable is usually sitting perfectly well in its grooves. Nothing looks wrong with the spooling. The tilt is coming from the drum's position relative to the shaft rather than the cable's position on the drum.

How you can tell: A tilt that has grown gradually over days or weeks, with both cables spooling neatly. Sometimes there's a witness mark on the shaft where the set screw has been walking.

Where to stop: Re-tightening a drum set screw sounds like a wrench job and isn't. The drum has to be re-clocked to the correct position against the other side while the spring tension is held — and holding that tension is the entire job, not an incidental part of it.
3

The counterbalance failed and the opener has been racking the door

High risk — call a technician

Here's where a broken spring genuinely does end up producing a crooked door, just not the way it's usually described.

When the springs stop carrying the weight, the opener becomes the lifting mechanism — and the opener connects to the door at a single point, at the center of the top section. Lifting a couple of hundred pounds from one center point on a door engineered to be lifted from both bottom corners makes the door flex. The center leads, the outer corners lag, and the whole assembly works through its travel twisted.

Do that for a handful of cycles and the tilt becomes structural rather than momentary: hinges take permanent set, the cables spool unevenly because the corners aren't arriving at the right heights, and now you have both a spring problem and a geometry problem.

This is why the spring page and this one are neighbors on the failure chain. It isn't that one spring caused a tilt. It's that a failed counterbalance plus continued use causes a tilt.

How you can tell: A visible gap in the spring coil, an opener that sounds like it's working hard, a door that got heavy suddenly, and the tilt appearing after all of that rather than before.

Where to stop: Two faults are now stacked. The spring has to come first — nothing about the door's geometry can be corrected while the counterbalance isn't carrying anything. Mention both when you call so we bring springs and cable hardware in one trip.
4

One side of the door is being physically held back

High risk — call a technician

The straightforward version, and worth ruling in early because it's the one where something obvious is going on.

Candidates, in roughly the order we find them: a manual slide lock partly engaged on one side, which is startlingly common on doors where somebody used the lock during a vacation and forgot; a roller that has seized and is skidding rather than rolling; a hinge that has cracked or lost a fastener so the section end isn't being carried properly; a shelf bracket, garden tool or storage rack drifted into the track's path; and a vertical track knocked out of plumb so the rollers on that side are fighting the channel the whole way.

The shaft turns evenly through all of this. Both cables take up correctly. But one bottom corner physically cannot follow, so the door twists — and the twist is what you're looking at.

How you can tell: The tilt is present from the first inch of movement rather than developing with height, and there's usually a noise from the side that's binding.

Where to stop: Even when the cause is as simple as a lock left thrown, the door has been racking against it, and racking loads hinges and end stiles in a direction they aren't designed for. Worth having the door checked rather than just releasing the lock and carrying on.
5

A track, bracket or roller carrier has moved

High risk — call a technician

Track hardware defines where the door is allowed to be. Move it and the door has no choice but to follow.

The specific culprits: a jamb bracket whose lag screws have backed out of the wood, so the vertical track has drifted toward or away from the door on that side; a flag bracket that has shifted, which changes the alignment where vertical meets horizontal; a top roller carrier that has worked loose, letting the top of the door lean; or a horizontal track hanger whose fixing into the ceiling framing has pulled.

Around here, the cause behind the cause is usually thermal. Garage framing in Gilbert or Chandler goes through a serious temperature swing every day of the year, and lag screws in wood that keeps moving don't stay as tight as they were. Nothing breaks. Everything shifts a little, and the door reports the shift as a tilt.

How you can tell: The tilt is consistent rather than progressive, and there's visible evidence in the hardware — a bracket standing proud, a lag screw you can turn with your fingers, a track that isn't parallel to the jamb.

Where to stop: It's tempting to snug up a loose lag and call it done. The problem is that the screw hole has usually elongated, so it'll come loose again, and the track position needs measuring against the door rather than eyeballing. Re-anchoring into sound material is part of the fix. Measuring and re-anchoring it happens on the visit, alongside the garage door cable repair itself.
6

The door is square and the floor isn't

Basic check

Worth stating clearly because a good number of people arrive here with this rather than a mechanical fault.

If the door hangs and travels perfectly square but there's a wedge of daylight under one end when it's fully closed, the door isn't crooked — the concrete is. Garage slabs are poured with a drainage fall, and around the Phoenix area expansive soil means plenty of them have settled further since. A slab that has dropped three-eighths of an inch at one corner produces a gap that looks alarming and means nothing about the door.

The reason it's worth separating from everything above: this is a sealing problem, not a lifting problem, and the fix is at the bottom of the door rather than at the shaft.

How you can tell: Measure bottom edge to floor at both ends with the door partly open — it'll be equal. The gap only appears when the door is fully down, and it follows a visible dip or slope in the concrete.

Where to stop: Nothing risky here at all. If the gap bothers you — and in this climate it should, because that's where dust, heat and scorpions come in — the answer is a seal that takes up the variation, not an adjustment to the counterbalance.

What you’ll need if you’re doing this yourself

  • A tape measure — measuring bottom edge to floor at both ends is the single test that separates a tilted door from an uneven slab
  • A flashlight — the drums are above head height at each end of the shaft, and cable spooling is impossible to judge in shadow
  • Your phone camera — a photo of each drum, taken from the same angle, makes the difference between them obvious — and tells us what to bring

Things not to do — and why

× Don't diagnose this as one broken spring

Both torsion springs share a single shaft and turn together. A break makes the door uniformly heavy, not lopsided. Chasing the wrong part costs a visit and leaves the actual cable fault alone.

× Don't keep running the door to monitor it

Every cycle drives the rollers harder against the track lip and lets the misbehaving cable wander further across its drum. Monitoring it is the same activity as making it worse.

× Don't try to lift a slack cable back into its grooves

A cable that looks limp is still part of a system holding the door's full weight under wound spring tension. Slack on one side doesn't mean the load has gone anywhere — it means it moved.

× Don't loosen a drum set screw to re-clock it

Releasing a drum from the shaft while the spring is wound hands the entire counterbalance to nothing. Winding bars and a controlled procedure are what make this a repair rather than an event.

× Don't touch the bottom brackets to “even things up”

The bottom brackets anchor the lift cables and carry the full tension the springs hold. The factory puts a warning label on them, and a crooked door is not the moment to test whether it's overcautious.

× Don't shim or pack under one end of the door

It hides an uneven gap without changing why the gap exists, and on a genuinely tilted door it introduces a hard point that the door then drives itself into.

× Don't assume it's fine because it still opens

It opening is what's causing the damage. A tilted door works every cycle, right up until the cycle where a roller leaves the channel.

What makes this show up here

Two Arizona factors feed this symptom, and they work on completely different timescales.

The slow one is thermal. A garage in Mesa or Queen Creek runs through a daily temperature swing that most of the country only sees seasonally, and it does it year-round. Fasteners in wood framing walk. Set screws relax. Nothing announces itself — the door just gets a fraction less symmetrical each year until the tilt is visible from the driveway.

  • Set screws relax with heat cycling — the drum clamps that hold your door square sit in a garage that expands and contracts every day. Loosening is gradual and invisible until the tilt shows.
  • Slabs settle here — expansive soil moves floors, which produces the uneven closed gap that gets mistaken for a crooked door. Measuring rules it in or out in thirty seconds.
  • Springs fatigue faster in extreme climates — springs here rarely reach the life a mild climate would give them — and DASMA's cycle-life guidance is narrower than it's usually quoted, pointing at doors left standing open rather than at ambient heat, and a counterbalance that fails early is what puts the opener in the position of racking the door.
  • Monsoon silt in the drums — fine dust settles on the shaft and drums and works into the cable wraps. It's abrasive, and it doesn't help a cable stay where it belongs.
  • Summer avoidance — a door that starts running a little uneven in June frequently doesn't get looked at until the weather breaks. Those are the calls that arrive as off-track doors in October.

Keeping the door square

Symmetry is easy to check and easy to lose. These are the habits that keep it.

  • Watch a full open from the driveway twice a year — the bottom edge should stay parallel to the concrete the entire way. Ten seconds, and it catches every version on this page early.
  • Compare the two drums when you're in the garage anyway — a cable in single-file grooves on both sides is what normal looks like. Once you've seen it, the wrong version is obvious.
  • Never let the door land on anything — an object under the door goes slack-cable-then-jumped-groove in one cycle. That's the origin of most spooling faults we find.
  • Check the track bracket lags annually with a socket wrench. If one turns by hand, the geometry has already started drifting.
  • Stop using a manual slide lock if you have an opener — a lock thrown against a powered door is a fast route to a racked, twisted door and a stripped drive gear.
  • Have the cables inspected when the springs are replaced — cables and springs age together, and the moment tension is off the shaft is the cheapest time to look at both.
  • Act on a tilt the week you see it — an inch of skew is a cable adjustment. An inch of skew ignored for a month is usually cables, rollers and track.

Where this sits in the sequence

This is the middle stage of the most common failure chain on a residential door — and it's the last stage where the repair is still small. Each step here genuinely causes the next.

Plenty of doors arrive at this stage without a spring failure — a cable can jump a groove on a perfectly healthy door. But once a door is here, the two steps that follow are the same either way.

How we put a door back to square

Squaring a door means restoring equal cable take-up on both sides, and that has to happen with the spring tension under control from the first move to the last.

What we do on a visit for this
  • Measure the actual out-of-square at the bottom edge and at the top, to establish where the twist lives
  • Bring the spring tension under control before any cable or drum is disturbed
  • Unwind and re-lay both cables into their drum grooves in a proper single layer
  • Re-clock both drums to matched positions on the shaft and re-seat the set screws into sound bearing surface
  • Inspect both cables full length for crushing and broken strands from the overwrap, and replace in pairs if either is compromised
  • Check the shaft for run-out and the center and end bearings for play
  • Check every hinge for the permanent set that racking leaves behind
  • Confirm both vertical tracks are plumb and correctly spaced from the door
  • Re-tension and balance the door so it holds position anywhere in its travel
  • Cycle under power and re-run the safety reversal test the way UL 325 requires

You'll get a written quote before any work starts.

What moves the number on this one

Squaring a door is a labor-led job. What changes the total is how much hardware the skew has already damaged.

  • Whether the cables can be reused A cable that has been crushed between its own wraps has damaged strands. Those get replaced, and cables are replaced in pairs so both sides have matched condition.
  • Drum condition Grooves that have been worn or burred by a cable riding out of them won't hold a cable properly afterward. A worn drum has to go.
  • Whether the counterbalance is intact If a broken spring is why the door has been racking, the spring work is the main job and the squaring is part of it.
  • How many cycles it ran crooked Hinges take permanent set, rollers wear their stems oval, and end stiles can rack. A door caught the same week is mostly labor.
  • Whether the track needs re-anchoring Lags that have pulled out of the jamb need fresh material to bite into before the geometry will hold, and that's extra work at the opening rather than at the shaft. It's the one thing that reliably adds time at the opening to a garage door cable repair.
  • Roller condition on the side that was fighting The rollers on the binding side take the brunt. They're inexpensive individually and usually replaced as a set.

You'll get a written quote before any work starts. If you're due anyway, our full tune-up is $39.99 — same price in every city we serve.

Still stuck? We’ll come take a look.

Same-day service is our standard across Mesa, Gilbert, Chandler, Queen Creek, Scottsdale, Phoenix, and the rest of the Valley.

Due for a check-up while we’re out? Our full tune-up is $39.99 — same price in every city we serve.

Questions we get asked about this

Where this information comes from

Serving the Valley

Where we come out

We’re a family-run shop based in Mesa, and we cover the whole Phoenix metro. Same-day service is our standard — pick your city, or just call (602) 935-9766 and we’ll find the soonest slot that works.

Not sure if you’re in range? Give us a call — if we can’t get to you, we’ll point you to someone who can.

Mesa-based · Serving the whole Phoenix Valley

Want us to just take care of it?

If you’ve worked through this and you’d rather have someone who does this every day handle it — that’s us. Tell us what your garage door is doing and we’ll come diagnose it properly.

  • Same-day service is our standard
  • Family-owned right here in Mesa
  • Straight answers — we’ll tell you if it’s not worth fixing
  • Written quote before any work starts
Due for a check-up anyway? Our full tune-up is $39.99 — same price in every city we serve, and we’ll go through the whole system while we’re there.
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