Awning Arm Replacement: Bent Arms, Weak Springs and Finding the Right Arm

You need a new awning arm when an arm is bent, a casting at the shoulder or elbow is cracked, the belt, chain or cable across the elbow has stretched or broken, or the springs can no longer pull the fabric taut. Straightening a bent arm rarely works for long, and adjusting worn springs only goes so far. The replacement has to match your awning exactly: same brand and model series, same projection (arm length), the correct left or right hand, and the same shoulder fitting. Fitting it is a technician job on almost every lateral-arm awning, because each arm holds a strong spring that can whip open with enough force to cause serious injury.

If your arms are intact but will not fold back into the hood, start with awning arms won't close instead; that is often an adjustment, not a replacement. For a sense of how arms fit into the whole mechanism, see awning parts.

How a lateral arm works

Each lateral (folding) arm has two sections joined at an elbow. The rear section attaches at the shoulder to a bracket or a square torsion bar along the wall; the front section attaches to the front bar. Inside the arm, one or more heavy springs pull on a belt, chain or steel cable that wraps around the elbow joint. That pull tries to straighten the arm, which pushes the front bar out and keeps the fabric tight.

The important consequence: an arm has the most stored energy when it is folded, the state it spends most of its life in. Retracting the awning winds fabric onto the roller and forces the arms to fold against their springs. Nothing about a closed awning tells you how much force is waiting in the arms.

Why arms fail, most common first

1. Wind damage while extended. Uplift or a strong gust bends the forearm or twists the elbow. This is the leading cause of bent arms, and often comes with damage elsewhere.
2. Worn or broken elbow belt, chain or cable. Symptoms are an arm that will not straighten fully, a sudden loss of tension on one side, or a snapping noise followed by a limp arm.
3. Tired springs. After many years and thousands of cycles, springs lose force. Fabric that used to be drum-tight sags, and ponding begins (see awning water pooling).
4. Load from water or snow. A pond or snow on an extended awning can push the arms down until the elbow or shoulder deforms.
5. Corrosion. Salt air attacks steel pins, chains and fasteners inside the arm; see awnings in coastal environments.
6. Impact. Ladders, vehicles or a retracting awning closing onto an obstruction.

Symptom, cause and fix table

How to diagnose an arm problem

1. Extend fully on a calm day. If an arm is cracked or the awning drops unevenly, stop and leave it as it is rather than cycling it again.
2. Sight along each arm. From the side and from below, look for any bow in the extrusions and twist at the elbow. Compare the two arms; they should be mirror images.
3. Compare tension. Press up gently on the front bar near each arm. Both sides should resist equally. A soft side points to a failed belt or tired springs on that arm.
4. Watch it close. Both arms should fold at the same rate and lie parallel in the hood. A bent arm often closes late, hits the hood, or leaves a gap.
5. Inspect what the arm attaches to. Check the shoulder casting, the bracket, the torsion bar and the front bar for cracks or bends. Wind that bends an arm often loads these too; see broken awning brackets.
6. Find the identification label. Look on the roller end caps, inside the hood, on a bracket, and in your purchase paperwork for the brand, model and serial number before calling anyone.

Bent arms: straighten or replace?

Most residential lateral arms are aluminum extrusions with cast aluminum or steel joints. Bending an extrusion back stresses the metal a second time at the same spot, and it can crack there later, sometimes under load with the awning extended. Even a slight residual bend changes how the arm folds, so it rubs the hood, scuffs the fabric, or prevents full closure. The internal belt or chain may also have been stretched in the event that bent the arm.

For those reasons, technicians and manufacturers generally replace bent arms rather than straighten them. The only common exception is a minor bend in a non-structural cover or trim piece. If one arm is bent, assume the other took load too and have it checked.

Matching the right replacement arm

Arms are not universal. Before ordering, gather all of the following:

• Brand and model series. Arms from different series of the same brand often have different shoulder fittings or spring forces.
• Serial number or order number, which lets the maker confirm the build year and any running changes.
• Projection. Arms are sold by the projection they produce, not by measuring the arm itself. Measure from the wall to the front bar with the awning fully extended, and compare with your paperwork.
• Hand. Left and right arms are usually mirror images; confirm which side is damaged when viewed from below or from the patio, as the maker specifies.
• Shoulder fitting. Note whether the arm clamps to a square torsion bar or bolts to an individual bracket, and the bar size if applicable.
• Elbow type. Belt, chain or cable, if the maker offers more than one.
• Frame color, so the new arm matches.
• Width and pitch setting, which some makers use to confirm spring force.

Major brands typically keep arms available for current and recent models through their dealers or parts departments. Older or discontinued awnings, and budget imports sold without a parts program, are where replacement gets difficult; generic "universal" arms rarely match spring force, length and shoulder geometry well enough to work safely. If no matching arm exists, that usually tips the decision toward a new awning (see awning repair vs replace).

Replace one arm or both?

On an awning more than a few years old, the undamaged arm's springs have relaxed somewhat. A brand-new arm on one side then pulls harder than the old arm on the other, which can tip the front bar, wind the fabric unevenly and make the awning roll crooked (see awning retracts unevenly). Many technicians recommend replacing in pairs once an awning is past roughly five to seven years, and replacing a single arm on a young awning. Ask what your technician recommends for your brand.

The spring tension hazard

New arms are usually shipped folded and held closed by a strap, bracket or tie. Technicians fit the arm at both ends while it is restrained, then release it in a controlled way with the canopy and front bar supported. Removing an old arm reverses that sequence and often requires restraining a damaged arm whose spring force is unknown. This guide deliberately does not give a removal procedure: the correct steps vary by brand, and errors are the leading way homeowners get hurt working on awnings.

RV awnings are different. Their arms are usually vertical struts with rafters, and the dangerous stored energy is in the torsion spring inside the roller tube. See RV awning adjustment for those systems.

When to call a pro and typical cost

Arm replacement on a residential lateral-arm awning is a professional job. Rough 2026 US figures, varying by brand, projection and region:

• Replacement arm (part): commonly about $150 to $600 each for mainstream residential sizes, more for long projections and premium brands.
• Labor: often about $200 to $500 for one visit to fit one or two arms, more if fabric or brackets also need work.
• Belt or chain rebuild, where the maker supports it: usually less than a full arm.

For costs across all repair types, see awning repair cost, and check your awning warranty first: frame and arm warranties often run longer than fabric warranties, though wind damage while extended is commonly excluded.

Prevention

• Retract in wind; a motion sensor protects a motorized awning when nobody is home (see wind and sun sensors).
• Never leave the awning out in heavy rain or snow, and keep pitch steep enough to drain.
• Keep the closing path clear of furniture, plants and ladders.
• Lubricate elbow and shoulder pivots only with the product the maker specifies; see awning lubrication.
• Rinse arms in coastal areas to slow corrosion of pins and chains.

Frequently asked questions

Can I replace an awning arm myself?

On most lateral-arm awnings it is not a safe DIY job. Each arm holds a strong spring that is at its highest tension when the awning is closed, and releasing it without the maker's restraints and procedure can cause serious injury. Some manufacturers document a homeowner procedure for specific models; if yours does not, have a trained technician fit the arm.

Can a bent awning arm be straightened?

Usually not reliably. Arms are aluminum extrusions, and bending one back stresses the same spot again, so it can crack later under load. A residual bend also stops the arm folding cleanly into the hood. Manufacturers and technicians generally replace bent arms and inspect the shoulder, bracket and front bar, which often take damage in the same event.

How do I know which replacement arm to buy?

Record the brand, model series and serial number from the label on the roller end, hood or bracket, then measure the projection with the awning fully extended. Note which side is damaged, whether the arm clamps to a square torsion bar or bolts to a bracket, and the frame color. Give all of this to the manufacturer or dealer so they can supply the exact arm.

Should both awning arms be replaced at the same time?

On awnings older than about five to seven years, replacing both is often recommended because the old arm's springs have weakened. A new arm on one side and a tired one on the other can tip the front bar and make the fabric roll crookedly. On a young awning, replacing only the damaged arm is usually fine. Your technician can compare the tension on both sides.

How much does it cost to replace an awning arm?

Typical 2026 US figures are about $150 to $600 per arm for mainstream residential sizes, with labor often about $200 to $500 per visit. Premium brands and long projections cost more. Replacing both arms on a mid-size awning commonly lands around $500 to $1,700 installed, which is well below a new awning if the fabric and brackets are sound.

Sources and further reading

• European Committee for Standardization (CEN), EN 13561: External blinds and awnings, performance requirements including safety
• Professional Awning Manufacturers Association (PAMA), awning service and safety guidance
• Advanced Textiles Association (formerly IFAI), Specialty Fabrics Review: articles on retractable awning service
• Occupational Safety and Health Administration (OSHA), Portable Ladder Safety fact sheet