Your torsion springs are responsible for cycling your door. Although your automatic opener initiates the cycling process, your torsion springs are the components that perform the heavy lifting. For this reason, it's necessary you do everything in your power to keep your torsion springs in good condition. A well-maintained set of torsion springs will last between 15,000 to 20,000 cycles. However, these two problems will reduce the lifetime expectancy of your springs and force you to arrange for premature repairs or adjustments:
Overtravel occurs when your automatic opener uses too much power while cycling your door into the open position. When overtravel occurs, your door will travel past the point at which your door manufacturer designed the door to stop cycling. This issue typically causes the top rollers of a door assembly to be pulled out of their tracks, but this side effect may not be present in your door.
Overtravel causes your torsion springs to wind further than the point at which they're supposed to stop. Prolonged overtraveling will reduce the elasticity of your springs—which, in turn, reduces the amount of weight your springs are capable of tolerating.
Luckily, overtravel is a fairly easy problem to fix. Two main issues cause overtravel:
Improper Lift Power
To test for improper lift settings, close your door and keep your opener's remote in hand. Stand on the interior side of your closed door and use your remote to begin the cycling process. Once the door is a couple feet off the ground, grab onto a non-moving section of your door frame and apply a few pounds of downwards pressure.
If your door immediately stops, then your lift settings are adjusted properly. However, if your door continues to rise, then you must reduce the upwards lift power by turning the corresponding knob on your opener's housing.
If you must adjust your lift power, do so in small increments. Each time you adjust the lift power, test your door. By working in small increments and testing your lift power after each adjustment, you can achieve optimal power for efficient cycling.
Your chain should be fairly tight, but it should still sag about halfway down your chain drive. If your chain is completely taught, then loosen it by adjusting the nuts on the chain bolt (located directly above your operator). Loosen the nut opposite of your chain while tightening the nut closest to your chain. Repeat this process until your chain has a slight amount of sag.
Incorrect Load Rating
If the torsion springs currently used in your door assembly are not the ones provided by your door's manufacturer, then they may not be rated for the weight of your door. Torsion springs that are used to lift doors heavier than the load for which they're rated will wear out well before their cycle rating. Additionally, they have an increased chance of breaking mid-cycle.
However, the load rating of your springs won't be easy to determine. Unless you're able to find a brand name or model number on your springs, you'll have to pay attention to the symptoms produced by overworked springs to determine whether or not your springs are suitable for the weight of your door.
Typically, springs that are too weak to lift a door will cause the closing cycle of your door to occur significantly faster than the opening cycle. This is due to the springs struggling to lift the weight of your door and stabilize it during its descent.
If you have trouble adjusting your lift power and chain, or if you suspect that your springs aren't rated for the weight of your door, then hire your local garage door technician from a place like The Garage Doctor to inspect your door assembly and perform the necessary repairs. If you wait any longer, your springs may break mid-cycle and leave you unable to back your vehicle out of your garage.