9.15 Install the bolts to secure the stationary center cones to the center bracket. Position the shaft here so it is the same distance from the header as the shaft is at each end. Finger-tighten the nuts until the stationary cones are flush against the center bearing plate. Forcing the cones by tightening the bolts may break a cone if it is catching on a bearing. Winding torsion springs with cracked cones can cause the springs to spin loose and the bars to fly. Secure the bolts.
While it would be wonderful if door springs lasted forever, the reality is that the simple act of opening and shutting the door multiple times every day isn’t easy. It’s hard on the springs, even though they’re built to do it. Most springs will last for a while, but they won’t last forever. The regular wear and tear of endlessly opening and shutting the door breaks them down and eventually, they’ll need to be replaced. https://m.youtube.com/embed/Z_eZc-kh40c
Torsion springs do not last forever, regardless of what some companies claim. “Lifetime” springs do not exist – all springs have a lifespan. Most builders typically install the lowest costing door available and with that generally comes lower cycle springs. A torsion spring’s life is determined by the number of cycles the spring is rated to last. Whenever the door goes up and down is what is referred to as a “cycle.” The springs that builders install can last as little as 7,500 cycles which means the average homeowner could get 3-5 years of life. http://y2u.be/Z_eZc-kh40c