Posted March 2nd, 2020 at 12:02 pm by Dan Musick
This week one of our wholesale customers called me about stripped operator drive sprockets. This is usually caused by overstress. I recommend the service tech disconnect the drive chain and check the door balance as per the instructions we have on our “Balanced Garage Door” blog. His initial diagnosis was that the metal had fatigued. I suggested he adjust the springs until the door stays open by itself, and then check to see how heavy the door was when closed. As it turned out the spring had fatigued, but not abnormally given that this was a high cycle car wash door.
After springs are wound in the manufacturing process, they need to be baked for a few hours. Sometimes mistakes are made or corners are cut. As a result, a service company can end up with a load of half-baked torsion springs, and have a nightmare warrantying the materials.
For about 15 years I was employed by Area Door Service in Elgin, IL where I repaired residential and industrial garage doors and openers. On one occasion I was dispatched to a small residential door where the cables had come of the drums and the door would not close because the cables were tangled. While reinstalling the cables I realized that the problem was caused by the spring not having enough tension. The simple fix was to add about a turn of spring tension to prevent the problem from recurring. I assumed the spring was never wound correctly.
About a week later I was recalled to the same job to correct the same problem. As I analyzed the door I concluded that the spring had lost another turn of tension in the short time since I had been there. At that point, I had to replace the spring to avoid the same problem from recurring. The original spring on this fairly new door was half-baked.
The American spring manufacturers conform their practices to the highest standards in the industry. That is why we have never bought springs from China. The critical baking time is the easiest standard to compromise because a spring that is not properly baked looks identical to one that is properly baked. Even when it is installed the spring may work fine for several days, weeks or months.
Chinese manufacturing has improved over the past several decades, but trust in consistent quality is still an issue. One container of springs from China sold on EBay or Amazon could be very profitable. The second container may have springs with compromised heat treating can put a company like ours out of business.