How to Change the Springs on Garage Cables

Close the garage door. Set up a ladder underneath the garage door motor, located in the center of the garage. Unplug the motor from the electrical outlet. Pull on the red cord that extends down from the center track.

Measure the length of the coil. If it is broken, measure the first section of coil then the second section and add these two lengths. Do not touch the springs while taking this measurement. Hold the tape measure up to the second section of coil. Count out 10 coils and write down this measurement, then count out 20 coils and write down this measurement. Use these measurements to select new garage door coils.

Place an 18-inch long, 1/2-inch, cold-rolled steel bar into the bottom hole in the winding cone's bottom edge. The winding cone is located at the outer end of the spring coil. Position the steel bar so it holds the pressure of the spring.

Hold onto the bar with one hand. Remove the cone's set screws with an open-end wrench. Do not use a socket wrench. Continue to firmly hold onto the bar with one hand when all the set screws have been removed.

Insert a second bar into the cone's hole directly above the first hole. Slowly pull the first bar out and gently lower the second bar. Then put the first bar into the next hole, directly above the second bar. Pull out the second bar and gently lower the first bar. Continue to alternate bars in this way until the spring has no more tension. Repeat with the garage door's second spring.

Remove the bolts that hold the cones on the spring's inner end to the brackets on the walls. Slide the springs down the bar, in opposite directions, toward the cable drums -- the round pieces at either end of the bar.

Loosen the cable drums' set screws. Slide the cable drums off of the bar ends. If the drum seems stuck, locate what is holding it back and use a metal file to smooth down the bar so the drum slides off. Slide the old springs off of the rod and slide the new springs on. Double-check that you have the correct spring on each of the bar's ends. The red cone spring goes on the bar's left side. Place the drums back onto the bar ends and tighten the set screws.

Slide the new springs all the way down the bar. Secure the springs' inner ends to the brackets on the wall with the supplied bolts.

Insert a steel bar into the outer cone's bottom hole. Push the bar up and insert the second steel bar into the bottom hole while removing the first bar from what is now the side hole. Push the second bar up and insert the first bar back into the bottom hole. Continue to wind the spring up, alternating bars. Count the times you make a turn and stop winding when you have reached 30 turns for a 7-foot garage door and 34 turns for an 8-foot garage door.

Tighten the cone's set screws with an open-end wrench. Wind the spring on the other side in the same way and tighten the set screws. Properly wound springs allow the garage door to stay in its closed position and hold it in an open position when you lift it. Release tension from both springs if the door does not remain closed.

Reengage the red cord you disengaged in Step 1. Lift the garage door all the way up. Plug in the motor.