Why You Should Always Replace Both Garage Door Springs at the Same Time

The most common pushback I hear when someone comes out for a spring replacement on a two-spring door: "Can you just do the one that broke?"

Technically yes. Practically - almost never the right call. Here's why.

They're the same age doing the same work

Two torsion springs on a double-car door. They go in together. They run every single cycle together. Every open, every close, same stress, same wear.

One breaks first because springs don't fail at identical times - minor manufacturing differences, tiny variations in how they were wound, slight differences in load distribution. One gives out a few months before the other. But the other one is right there with it in terms of fatigue.

The spring that just broke was at the end of its rated life. The other spring is also at the end of its rated life. One happened to go first. The second one is following.

The math on replacement timing

Spring replacement including parts and labor - $150 to $300 depending on single or double setup. Service call included in that price.

If you replace only the broken one, you pay $150-200 now. Then in 3 to 6 months - which is genuinely how often the second one goes shortly after - you pay another service call, another spring, another $150-200.

Total: $300-400 over two separate visits, two separate hassles, two separate mornings with the door out of commission.

If you replace both now: $200-300 total, one visit, done.

The cost difference is small and in some cases replacing both is actually cheaper than two single-spring replacements. The inconvenience difference is more significant - one service call versus two.

The load imbalance problem

Here's the mechanical reason, beyond just the age argument.

When one spring breaks, the remaining spring is suddenly doing all the work alone. The door is still being used. Every cycle, that one working spring carries twice the load it was designed to share.

This accelerates its fatigue significantly. A spring that might have had 6 months left before the first one broke might now have 6 weeks. You've put it under double load during its final miles.

Replacing only the broken spring and leaving the worn one means the new spring is now paired with a spring that's already fatigued. They're not matched. The door doesn't balance evenly. The new spring does more work than it should, the old one does less. Neither performs optimally.

Mismatched springs and door balance

Torsion springs get wound to a specific tension based on the door weight. Both springs on a two-spring setup need to be wound to matching tension for the door to travel evenly.

When you replace one spring, the new spring is at full tension. The old spring has lost some tension from years of use. Now you have two springs at different tension levels.

The door works - it opens and closes - but it's not balanced correctly. One side is doing more than the other. The opener arm takes lateral stress. The rollers wear unevenly. The cables wear unevenly. The door might close with a slight tilt.

This is also fixable by adjusting the old spring's tension, but you're adjusting a worn spring that's already near its end. The better solution is just replacing both.

The cost argument against replacing both - and why it doesn't hold

People choose to replace only the broken spring because the price difference in the moment looks significant. $200 for one spring vs $300 for two. "I'll just do one, save the hundred bucks."

But the second spring is coming. It's not a question of if, it's when. And when it goes, you're paying for:

Another service call. Another spring. Another morning without the car. Another appointment, another wait.

The hundred dollars you saved gets erased and then some. The math always lands in favor of doing both at once. Every time.

If someone argues against replacing both - what to ask

If you're talking to a tech and they say you only need to replace the broken one - that's not necessarily dishonest, it's just a different approach. Some companies let you decide. Ask specifically:

"How old is the other spring?"

"Has it been tested for balance and tension?"

"What's the realistic timeline before the second one goes?"

A tech who's being straight with you will tell you the second spring is also at risk and explain why doing both now makes sense. If they just want to do the quick single-spring job without discussing it - that's fine, but you deserve to know what you're deciding.

High-cycle springs - while you're doing both

When replacing both springs, this is the right moment to ask about high-cycle springs. Standard springs rated for 10,000 cycles cost less upfront. High-cycle springs rated for 25,000 to 50,000 cycles cost $40-80 more per spring.

For heavy-use households - multiple drivers, garage as main entrance, door runs 8+ times a day - high-cycle springs pay for themselves quickly. You go from replacing springs every 3-4 years to replacing them every 8-12 years.

When you're already having both replaced, the incremental cost to upgrade is small and the return over the life of the springs is significant.

GarageDoorRepairz - when we come out for a spring replacement we'll always tell you the condition of the second spring and let you make an informed call. Give us a call and we'll get it done right.

The exception - when replacing one makes sense

There are situations where doing just the broken spring is genuinely reasonable. Might as well be honest about it.

The door is relatively new - under 4 or 5 years old with light use. The second spring hasn't used much of its cycle life. The age and usage math suggests it has years left. In this case, replacing the broken one and monitoring the other is defensible.

The springs are high-cycle springs that were installed specifically because the household has heavy use. If someone specifically paid for 50,000-cycle springs 3 years ago, and one broke early from a defect or unusual stress, the other spring at 3 years may genuinely have most of its life left.

The second spring was inspected and shows no signs of wear - good coil spacing, no rust, door balance tests well after new spring is installed. If a careful inspection says the second spring looks healthy for its age, keeping it and monitoring is reasonable.

In all other cases - both springs old, standard 10,000-cycle springs, heavy use - do both.

What balanced springs actually feel like

After both springs are replaced and properly tensioned, do the manual test. Disconnect the opener, lift the door to waist height, let go.

It should hold position. Drifts slightly - maybe an inch - is fine. Holds completely still is ideal. Drops or shoots up means tension isn't set right and you need to tell the tech before they leave.

Also try it at a quarter-open position and three-quarter position. A properly balanced door holds at any height. It shouldn't only hold at waist height and drop everywhere else.

Run the opener through a few cycles and listen. Both springs doing their share means the opener sounds relaxed - not strained, not working too hard. If the opener still sounds labored after spring replacement, something else is going on or the tension wasn't set correctly.

Keeping a record of spring replacement

Write down the date somewhere permanent - on the door frame, inside a maintenance log, on a note taped to the opener unit. Also note what type of springs went in. Standard 10,000-cycle or high-cycle, and if high-cycle, the rating.

This matters for two reasons. You know when to start watching for wear signs again based on your household's usage. And if you sell the house, it's useful information for the buyers - freshly replaced springs are a positive data point.

Most people have no record of when anything was done to their garage door. The homeowners who do are the ones who avoid surprises.

GarageDoorRepairz - we always document what we installed and when. Give us a call for spring replacement done right.