The really good thing about having torsion springs on the garage door is that when one breaks, not much happens:
We decided to spray money on the problem and make it go away; the Dutchess Overhead Doors tech was here the morning after I called: quicker than Amazon Prime and he works much faster than I can.
As nearly as I can tell from the checkbook (remember checkbooks?), an original (to us, anyway) spring broke shortly after we moved in. If so, that spring lasted nearly 17 years; at two open-shut cycles per day, let’s call it 12,000 cycles.
For the record, the springs are:
- 29 inches long
- 1-3/4 inch ID
- 0.250 wire
- 7 foot tall door
He cranked in seven full turns, corresponding to the “one turn per foot of door height” rule, although the door doesn’t quite balance on its own. I’d have done one more quarter-turn to match the chalk above the door (a good example of write it where you use it), plus maybe another for good measure, but I’m reluctant to mess with success:
Perhaps the 1955 springs were 32 inches long, but the tech replaced what he found both times. It’s a brute of a door, two generous cars wide, with plywood panels in heavy wood framing, plus a few pounds of filler I applied to the rather crazed surface before painting it some years ago.
I’m mildly surprised none of the dimensions changed in the last 60 years: the springs, end caps, pulleys, and hardware directly interchanged.