Customer Reports Door Crooked in the Opening: Cable vs Spring vs Track Translation Decision Tree

Why this matters

"The door is crooked" or "it looks tilted in the opening" is a customer translation, not a diagnosis. The same visible symptom, one side of the door sitting higher than the other, comes from at least three distinct failures: a cable that has slipped, frayed, or come off its drum; a spring that has lost balance on one side; or a track that has shifted out of plumb. Each has a different urgency and a different repair, and one of them, a cable issue, means the door is being held by tension that can release without warning. Getting the translation right on the phone and confirming it in the first two minutes on site keeps the tech from removing the wrong part and keeps everyone away from a stored-energy hazard.

A crooked door is a geometry problem. The two sides of the door are no longer rising at the same rate. The diagnostic question is always: which side is wrong, and what is making that side lag or lead.

Symptom presentation

The customer describes one or more of these:

• One bottom corner sits higher than the other when the door is closed or partly open.
• The door "jams in the corner" or scrapes one side of the opening.
• A loud bang was heard, then the door went crooked (classic broken-cable or broken-spring onset).
• The door rises evenly but lands crooked, or rises crooked and lands square.

The order matters. A door that lands crooked but rises straight points one way; a door that goes crooked the moment it lifts points another.

Quick checks

Disengage the opener and stop. Before touching anything, observe with the door closed:

• Look at both bottom corners against the floor. Measure the gap on each side.
• Trace each lift cable from the bottom bracket up to the drum. A cable lying slack, off the drum, hanging, or wrapped unevenly is your headline.
• Look at the springs. A broken torsion spring shows a visible gap in the coil; on a two-spring door, one broken spring unbalances the door instantly.
• Sight each vertical track for plumb and check the door-to-track reveal on both sides.

Isolation tree

Branch 1: One cable is off the drum, slack, or frayed. The crooked side is the side whose cable failed. The drum on that side stops lifting, so that corner lags. Confirm by lifting the door slightly by hand (if balanced) and watching the slack cable fail to take up. This is the most common cause and the highest hazard, because the remaining tension is now asymmetric.

Branch 2: A spring is broken or unbalanced. On a single-spring door, a broken spring makes the whole door heavy, not crooked, but a door that was hand-cranked or improperly wound can pull one side. On a two-spring door, one broken spring lets that side sag because the surviving spring cannot hold both drums evenly. Confirm by inspecting both springs for a coil gap and by testing balance: a door that is heavy AND crooked usually has a spring problem layered on the cable check.

Branch 3: Track shifted out of plumb. The cables and springs are intact, but a vertical track has moved, usually from a loosened lag or a vehicle bump. The door rides up the high side and binds. Confirm with a level on both verticals: a track more than roughly 1/8 in out of plumb that matches the crooked side is your cause.

Disambiguating the three: If a cable is visibly off or slack, that is the answer regardless of what else you find, fix it first. If both cables are seated and the springs are intact, check track plumb. If track is plumb and cables are seated but the door is heavy and crooked, look harder at the springs and drum winding.

Confirming diagnosis

• Cable confirmed: the slack or off-drum cable is on the lagging side, and re-tensioning that drum (after securing the door) squares the door.
• Spring confirmed: a coil gap is visible, or the door is heavy and balance is lost; correcting spring tension restores even rise.
• Track confirmed: a level reads out of plumb on the lagging side, and re-plumbing the track squares the reveal and clears the bind.

Reading the timing of the crook. When the door goes crooked in the travel cycle is a strong discriminator. A door that is square when closed but goes crooked as it lifts points at a cable or drum, the lifting side that fails is the side that lags the moment tension is applied. A door that lands crooked but rises straight, or sits crooked even at rest, points at a track shift or a section that has been off-track and re-seated unevenly. A door that is heavy throughout and drifts crooked under that weight points at a spring or drum-winding imbalance. Ask the customer, or watch one slow hand cycle, and the timing usually picks the branch before you touch a tool.

The cable-wrap inspection that catches the early failure. Before a cable comes fully off the drum it often wraps unevenly, overlapping itself or climbing the drum flange, which shortens that side's lift and tilts the door before any dramatic failure. Inspect both drums for clean, single-layer wraps seated in the grooves. An overlapped or climbing wrap on the lagging side is a cable/drum problem caught early, far better than waiting for the cable to jump off and drop that corner.

Why a two-spring door fails crooked and a one-spring door fails heavy. On a single torsion spring, a break unbalances the whole shaft and the door simply gets too heavy to lift, reading as heavy rather than crooked. On a two-spring setup, a single break removes support from that half of the torque, so that side sags and the door tilts. Counting springs and noting which broke tells you whether to expect a heavy symptom or a crooked one.

Remediation

Cable off-drum: secure the door, release spring tension if you must re-route the cable, re-seat the cable on the drum, re-tension, and confirm both drums wind evenly. Replace any frayed cable, never re-use it. Spring: replace or re-wind to spec and re-balance. Track: loosen the lags, re-plumb to within 1/8 in, retighten, and re-check the reveal. After any repair, run the balance test and the UL 325 contact-reverse test.

References

• UL 325, Standard for Safety for Door, Drapery, Gate, Louver, and Window Operators and Systems.
• ANSI/DASMA 102, Specifications for Sectional Doors (cable, drum, and balance specifications).
• DASMA Technical Data Sheet, Garage Door and Operator Spring Safety.