Left-wound vs right-wound torsion springs: how to tell them apart
Every torsion spring is wound one of two ways. A two-spring door needs one of each, and each has to go on its own side of the center bracket. Get it backwards and the spring loosens as you try to wind it, which is how winding bars get thrown.
Three ways to tell
- The wire end. Look at the spring end-on. On a right-wound spring, the free end of the wire points counterclockwise. On a left-wound spring, it points clockwise.
- The cone color. Winding cones are usually painted red for right wind and black for left wind. Treat the color as a cross-check: cones get swapped and paint wears off.
- The mounting side. On a standard two-spring door, viewed from inside the garage looking at the door, the right-wound spring sits on the left of the center bracket and the left-wound spring sits on the right.
DoorBot's spring color chart has the cone colors next to the wire-size codes.
Single-spring doors
The same rule applies: the side of the center bracket the spring sits on decides its wind. When you convert a one-spring door to two, keep the existing spring's side and add its opposite on the other side. See one spring or two for the conversion math.
Ordering the right pair
Give the parts counter the wire size, inside diameter, length and wind for each spring. If there's no paint left, measure the wire with the 20-coil method and confirm the size with the spring identifier. The spring calculator's spec sheet lists the wind for each spring, so the order is right the first time.
If they're swapped
A spring on the wrong side winds the wrong way: the coils loosen instead of tightening, and it won't hold the door. Stop, unwind fully, and swap the springs. Never force it. The torsion spring replacement procedure has the full sequence and safety checks.
Field rule: wire end first, cone color second, side of the bracket third. All three should agree before a bar goes in the cone.