Using your drill, add tension to the torsion spring. This system uses a single spring for a double door, but many manufacturers use two springs for a double door. The painted line on the spring acts as a gauge for the number of turns you put on the spring. To keep the bar from turning while you’re adding tension, attach a locking pliers to the bar on both ends of the spring. Apply lubricant for garage doors to the spring.
Safe automatic door openers. All automatic openers must now have an auto-reversing mechanism and photoelectric eyes located near the floor on both sides of the door (see photo). If the door is closing and the beam between the eyes is interrupted, the door will automatically reverse. If the eyes aren’t connected, the door won’t operate. For instructions on how to install a new garage door opener, see How to Install a Garage Door Opener.
Spring Issues - Unless it is due to an obstruction of some type, uneven movement of your garage door is likely caused by a problem with the spring mechanism. Roll-up doors generally have one center-mounted torsion spring. The tension on torsion springs is great. Therefore, it is necessary to call a professional for any repairs to this type of spring mechanism to avoid serious injury. Because replacement of these springs or cables in a garage door can take at least two or three hours of labor, costs can average $300 or more.