One Spring Broke: Replace One or Both?
On a two-spring door, one spring almost always breaks first. Here is why we recommend replacing both, what it costs relative to replacing one, and the rare cases where one is fine.
Most double garage doors, and a fair number of heavy single doors, run two torsion springs on the tube above the door. When one breaks, the tech will almost always recommend replacing both. Homeowners reasonably ask whether that is a genuine recommendation or padding the ticket. Here is the honest answer.
Why one breaks first
Two springs on the same tube were installed together and have done the exact same number of cycles. They are equally fatigued. One breaks first simply because no two pieces of steel are identical; a microscopic flaw in the wire or a slightly harsher winding gives one a shorter life. The other is at the same point in its life and typically fails within months.
Our post on spring cycle life explains the fatigue rating in detail.
The math on replacing one
Say you replace only the broken spring. The labor on that visit is the same as it would be for two, because the door has to be secured, the tube unwound, the spring swapped, and the door re-balanced regardless. The saving is one spring's parts cost.
Then, some months later, the second spring breaks. Now you pay the full labor a second time, plus the second spring. Total cost across the two visits is significantly more than doing both the first time, and you have had two mornings with the car stuck behind a dead door instead of one.
There is a second, less obvious cost. A new spring paired with a worn one does not balance the door evenly. One side lifts with more force than the other, the door can lift slightly crooked, and the opener strains against the imbalance. That is hard on cables, drums, and the opener's gear.
When replacing one is genuinely fine
There are a few real exceptions.
The other spring is recent. If a previous tech replaced only one spring last year and the older one has now broken, the recent spring may have plenty of life left. Replacing the old one with a matching spring brings the pair into line.
The door is being replaced soon. If the panels are rusting through and a new door is a few months away, a single spring to get you through is reasonable. We will say so.
The springs are visibly different ages already. Mismatched springs are common on doors that have been worked on by several companies. In that case the right fix is usually still a matched pair, but we will look at the wear on the older one before recommending.
What we do on a two-spring door
At Greggs Garage Door Services, the diagnostic is free and the quote is flat and written. On a two-spring door with one broken, the quote lists the matched pair, and we tell you plainly if your door is one of the exceptions where one spring makes sense. We also check the parts that fail alongside springs: the cables, which have been carrying uneven load since the break, and the bearing plates and center bearing on the tube. Our post on torsion tubes and bearing plates explains why those matter.
The door is then balanced properly, with the opener disconnected, so it floats at waist height. That test is what tells us the springs are right.
The single-spring door
If your door has one torsion spring, the question does not arise: it breaks, we replace it. What we do consider is whether the door would be better served by converting to two springs. A heavy door on a single spring works that spring hard and puts more stress on one side of the tube. Two smaller springs share the load and often last longer. It is a modest upgrade, and we quote it as an option, not a requirement.
Common questions
Is replacing both springs an upsell? No. On a matched pair with one broken, the second is at the same point in its life. Replacing both saves you a second visit and keeps the door balanced.
How much more does the second spring cost? The parts cost of one spring. The labor is the same either way, which is the whole reason it makes sense to do both now.
Can I just wait until the second one breaks? You can, but you will pay labor twice and run the opener against an unbalanced door in the meantime.
Do you replace the cables too? We inspect them. If they are frayed or have been stretched by the uneven load, we recommend replacing them in the same visit.
Call (423) 262-3147 or request a free quote. See our spring repair page for the service, and the spring replacement cost guide for what drives the price.
Garage door trouble in the Greeneville area?
Greggs Garage Door Services offers flat-rate repair and new door installation across Greene County, TN. A real person answers the phone, and the quote is always free.
