How to Adjust Garage Door Spring Tension (Safely)

Spring tension is the heart of how a garage door works — and the part most likely to send a DIYer to a GTA emergency room. After 15 years servicing doors across Toronto, Mississauga, and the wider GTA, I have seen what happens when a winding bar slips. This guide explains exactly how spring tension is adjusted, how to tell whether yours is off, and where the line sits between a safe homeowner task and a job for a trained technician.

Signs Your Spring Tension Is Off

Before touching anything, confirm the problem really is tension and not a broken part. These are the symptoms I diagnose most often when a door is out of balance:

• The door opens by itself or won’t stay closed. Too much tension overpowers the door’s weight and pushes it up.
• The door slams shut or feels very heavy. Too little tension means the door wins and the opener strains to lift it.
• The door stops partway and drifts. A door that won’t hold position when raised halfway is out of balance.
• The opener works hard, then reverses. An under-tensioned door makes the opener overheat and trip its safety reversal.
• One side lifts before the other. Often a cable or single-spring issue rather than pure tension — see our guide to a cable that came off the drum.

If instead you hear a loud bang and the door simply won’t open, you likely have a broken garage door spring, which needs replacement, not adjustment.

Torsion vs. Extension Springs: Know What You Have

The two spring systems are adjusted completely differently, and the safe approach depends entirely on which you own. Look above the door and along the upper tracks before you do anything else.

Feature	Torsion Springs	Extension Springs
Location	Mounted on a shaft above the door opening	Stretched along each horizontal track
How they store energy	By twisting (torque)	By stretching
Adjustment method	Winding cone + two winding bars	Move cable hook / S-hook to a different hole
DIY risk level	High — extreme stored torque	Moderate — still hazardous
Typical lifespan	10,000–20,000 cycles	8,000–15,000 cycles

Most newer GTA homes use a single or double torsion spring above the door. Older and lighter doors often use extension springs. If you have torsion springs and no winding bars, stop here and book a professional adjustment.

How to Adjust Extension Spring Tension

Extension-spring adjustment is the more homeowner-friendly of the two, because the energy is released in stages as you reposition the lift cable. Even so, the door must be fully open and locked before you touch a hook.

1. Open the door fully and clamp it. With the door all the way up, the extension springs are at their slackest. Clamp a locking plier onto the track below the bottom roller so the door cannot drop.
2. Locate the cable hook. Each extension spring connects to a lift cable through an S-hook or eye bolt anchored to the track hanger.
3. Move the hook one hole. To increase tension, shorten the cable by moving the hook to the next hole or knotting the cable shorter. To decrease it, lengthen the cable. Adjust both springs equally so the door stays even.
4. Test and repeat. Release the clamp, run the balance test, and adjust one hole at a time until the door stays put halfway.

How to Adjust Torsion Spring Tension (The Winding-Bar Method)

This is the procedure trained technicians use. I am describing it so you understand what is involved — not as encouragement to do it without proper tools and experience. A slipped bar at this tension has cost people fingers and worse.

What You Need

• Two solid-steel winding bars sized to your winding cone (never substitutes)
• An adjustable wrench or socket for the set screws
• A sturdy ladder, safety glasses, and gloves
• A locking plier or C-clamp for the track

Step-by-Step

1. Secure the door. Close it fully, disconnect the opener with the red release cord, and clamp the track just above a roller so the door cannot rise.
2. Mark the spring. Draw a chalk line down the length of the spring so you can count turns and see slippage.
3. Seat a winding bar and loosen the set screws. Insert one bar fully into the winding cone, hold it firmly, then loosen the two set screws on the cone. The spring’s full tension is now on your bar — keep your body to the side.
4. Wind in quarter turns. Using two bars in alternation, add tension (wind up) or relieve it (wind down) one quarter turn at a time. To raise a too-low door, add a quarter turn; to tame a self-opening door, relieve a quarter turn.
5. Re-tighten the set screws. With a bar holding tension, snug both set screws a quarter to half turn past first contact onto the shaft — tight enough to grip, not so tight you strip the screw.
6. Run the balance test. Remove the clamp and lift the door by hand to waist height. Repeat quarter-turn adjustments until it stays put, then reconnect the opener.

How Many Turns Does a Torsion Spring Need?

A common rule of thumb is one quarter turn of tension per foot of door height, plus four. A standard 7-foot door usually lands around 7.5 to 8 full turns (about 30 to 32 quarter-turns) past slack. But spring wire size, inside diameter, and door weight all change the number, so the turn count is only a starting point — the balance test is the real authority.

The Balance Test: How to Know the Tension Is Right

Every adjustment, on either spring type, is verified the same simple way. The balance test is the single most reliable check of spring tension and costs nothing.

1. Disconnect the opener. Pull the red release cord with the door closed.
2. Lift the door to waist height by hand and let go gently.
3. Read the result: A balanced door stays put. A door that drops needs more tension. A door that rises needs less.
4. Check full travel. The door should move smoothly and feel light from floor to fully open, with no heavy spots.

Common Mistakes to Avoid

• Using the wrong tools. Screwdrivers and rebar are the leading cause of spring injuries. Only solid-steel winding bars belong in a winding cone.
• Adjusting one spring on a double-spring door. On a two-spring setup, both must be matched or the door pulls unevenly and wears the cables — covered in our tune-up guide.
• Over-winding. Too much tension makes the door fly up, wears the opener’s up-limit, and accelerates cable fatigue.
• Ignoring worn cables. A frayed cable will fail soon after a tension change. Inspect cables and bottom brackets at the same time.
• Adjusting a broken or rusted spring. If the coil is gapped, cracked, or rusty, it needs replacement, not winding.

When to Call a Pro & GTA Pricing

For extension springs in good shape, a careful homeowner can rebalance the door. For torsion springs, my honest advice after 15 years in the trade is to let a trained technician handle it — the risk-to-reward ratio simply isn’t in your favour. Call a pro right away if you have a double-spring torsion door, a broken or rusted spring, frayed cables, or any uncertainty about the procedure.

Here is what spring work typically costs across Toronto and the GTA:

Service	Typical Cost (CAD)
Maintenance & tune-up (incl. balance & adjustment)	$100–$120 + tax
Cables & brackets	$180–$220 + tax
Cables with bottom brackets	$260 + tax
Single torsion spring replacement	from $280 + tax
Double spring setup (both springs)	$320–$460 + tax
Per spring (commercial / multi-spring)	$160 / spring
Torquemaster conversion to standard torsion	$530 + tax

A simple tension adjustment is usually folded into a $100–$120 tune-up. Because Royal Garage Doors includes a FREE service call with any repair (only a $120 diagnostic applies if you choose not to proceed), having a pro do it correctly costs little more than buying winding bars yourself. All spring work carries our 1-year labour and 5-year hardware warranty. For full, current pricing see our pricing page, and read what GTA homeowners say on our reviews page.

Serving every corner of the region, our team handles spring tension and replacement in Mississauga, Toronto, Brampton, and Hamilton. If your door turns out to need more than a tune-up, we also handle full door replacement and panel replacement.

Frequently Asked Questions

Can I adjust my garage door spring tension myself?

Extension-spring balance can sometimes be fine-tuned safely by moving the lift-cable hook to the next hole, but torsion-spring adjustment is genuinely dangerous and is not recommended for homeowners. A torsion spring stores enough energy to break bones or kill if a winding bar slips. If you do not own proper solid-steel winding bars and have never been trained, hire a technician. In the GTA, Royal Garage Doors includes a FREE service call with any repair, so a professional adjustment costs little more than the parts.

How many turns should a garage door torsion spring have?

As a rule of thumb, a torsion spring needs roughly one quarter turn of tension for every foot of door height plus four. A standard 7-foot door usually takes about 7.5 to 8 quarter-turns past slack (commonly expressed as 30 to 32 quarter-turns, or about 7.5 to 8 full turns). The exact number depends on the spring wire size, inside diameter, and door weight, so always fine-tune by the balance test rather than counting turns alone.

How do I know if my garage door spring tension is correct?

Disconnect the opener with the red release cord and lift the door by hand to about waist height. If the tension is correct, the door stays put without drifting. If it slams down, the springs are under-wound and need more tension. If it flies up, they are over-wound and need tension relieved. The door should also feel light and move smoothly through its full travel.

Why does my garage door open by itself or not stay down?

A door that creeps open or will not stay closed almost always has too much spring tension (over-wound springs) or springs that are too strong for the door. The over-tensioned spring overpowers the door's weight and pushes it upward. Relieving a quarter to half turn of tension usually fixes it. If the door instead crashes down or feels very heavy, the springs are under-tensioned or one has weakened and needs adjustment or replacement.

How much does it cost to adjust garage door spring tension in the GTA?

In Toronto and the GTA, a maintenance and tune-up package that includes balance check and spring adjustment runs $100 to $120 plus tax. If a spring is broken or worn rather than just out of adjustment, a single torsion spring replacement starts at $280 plus tax, and a double-spring setup runs $320 to $460 plus tax. Royal Garage Doors offers a FREE service call with any repair, so diagnosis costs nothing if you proceed.

Is it dangerous to adjust a garage door spring?

Yes. Torsion springs are wound to extreme tension and store enough energy to cause severe injury or death if a winding bar slips or a set screw fails. Most serious garage door injuries involve springs and cables. Never use screwdrivers or rebar as winding bars, never stand directly in line with the spring, and if you are unsure at any point, stop and call a professional technician.