Torsion Spring Replacement

Old 02-14-17, 04:23 PM
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Torsion Spring Replacement

I installed new torsion springs and I'm having an issue. Once I set the tension, 1 full turn for 1' of door height, I tried to manually open the door to test the balance. The right side cable drum sheared off at the cable slot.

What would cause this? Do I need to add tension or reduce tension?
Old 02-14-17, 06:20 PM
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Possibly it was cracked before?

1 turn for 1' of height? Never heard of that before. Normally you need to know the weight of the door. Then after a rough setting, you fine tune it based on how it operates.

Just looked at a Clopay chart and they say a 7' high door get 7.75 turns. So at one turn per ft you would be a bit under and the door would be "heavy". All depends on the door though. A double steel skinned insulated 2" door is going to weigh a lot more than a single skin uninsulated 1 3/8" door.
Old 02-14-17, 07:52 PM
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"Sheared off"... it has a key, and the key sheared? Or it has a set screw that wasn't tight and it spun?
Old 02-15-17, 03:21 AM
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General rule of thumb for a residential torsion spring is door height plus a half of a turn.... (but not always) I.E. 7 foot high door would requirer 7 1/2 turns. Different manufactures use different sized drums, if your drum is approx. 12 inches in circumference then this rule would apply.

Last edited by Doorman2722; 02-15-17 at 03:25 AM. Reason: spelling
Old 02-17-17, 10:37 AM
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Torsion Spring replacement

IF your drum is damaged in any way replace it. Now is the time when you have everything pulled apart. I would also recommend replacing the end bearing plates as well if you can. It is not too common for drums to break but I have definitely seen it before. Make sure the spring/springs you are using are the correct size for your door. This is crucial. Assuming you have the correct springs, wind each spring 7 full turns and check the balance of the door. if it feels heavy and wont stay up by itself when opened half way up you can start to add tension to the springs. increase the tension by a quarter turn per spring to be safe. check the balance and repeat if necessary. if the door is wanting to fly back/up when it is getting close to being all the way open but is still heavy when lifting off the ground initially, chances are the springs are not right for your door. Selecting the proper spring size can be tricky. Service Spring makes an app you can download on your phone that may be helpful. What type of door do you have? IF you could tell us the size and type of door(steel uninsulated, steel vinylback insulated, steelback insulated, wood, etc.) and then the size of the spring (wire guage, inside diameter, and length) we could probably help you out.

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