How to replace a broken garage door torsion spring.

Before you begin to disassemble your garage door's counterbalance system, inspect your garage door thoroughly for any damage that may have been the result of the spring's failure. Make sure the center support is securely fastened, as well as the track's flag brackets, jamb brackets and rear track hangers. Check for damaged cables, etc. Any discrepancies should be addressed before you work on that spring. Ensure that there is no tension on the spring or springs before you disassemble. If your door has only one spring: 1. Unbolt the stationary cone from the center support and slide it over towards the drum. 2. Take note of the position of the end bearing plate, then unbolt the bearing plate and slide it off the shaft. 3. Loosen the drum's set screws and slide the drum off the shaft. (You will probably have to tap it with a hammer and wrestle it off due to possible indentations made on the shaft by the drum's set screws.) 4. This will be a good time to file down any indentations that you may find on the shaft. 5. Slide the broken spring off the shaft. 6. Carefully slide the new spring onto the shaft. Avoid nicking or scraping the spring's wire. 7. Slide the drum back onto the shaft. 8. Slide the end bearing back onto the shaft and bolt it down in the same spot it was originally at. 9. Refasten the spring to the center support plate. 10. Go the opposite drum and ensure that the drum's set screws are tight and that the cable is wrapped properly around the drum. Clamp a "Vise Grip" onto the shaft so that it is up against the wall preventing the drum from turning allowing the cable to go slack. 11. Go back to the loose drum, reconnect the cable then turn the drum so that the cable wraps securely around the drum. Tighten the drum's set screws. 12. Check both cable's tautness, they should be the same. Adjust as needed. 13. Wind the spring with a couple of steel rods that fit securely and all the way into the winding plug's four holes. There is a chart at http://www.garagedoorsupply.com/torsionspringinstallation.html which will tell you how many turns to wind your spring to. This chart is only a guide, you must test your door's balance after the spring is wound and adjust the tension as needed. NOTE: If your door has two springs that share the center support then you MUST remove the tension completely from the spring that is not broken before you undo the stationary cone from the center support. As you may have realized by now, this repair is not rocket science. Anyone can do it provided they have a little mechanical aptitude, exercise caution and common sense. If you are unsure of your mechanical abilities, please do not attempt to replace a torsion spring. Refer to your Yellow Pages for a qualified garage door repairperson in your area.