Extension springs run along the sides of the garage door and are different from torsion spring that run along the front portion of the overhead door. Replacing garage door extension springs is a relatively minor job.
As a homeowner, you should never attempt to replace torsion springs. They are wound tight and only garage door professionals should replace torsion springs.
To replace your garage door’s extension springs, follow these steps.
1. Secure your garage door first
Fully open your garage door and secure it using clamps. C-clamps, piece of lumber or locking pliers work best here. Clamp the garage door just beneath the door roller at the bottom on both sides of the door. Test to ensure it is holding firmly. If using piece of lumber, prop the garage door open by placing the piece of lumber next to the roller tracks on both sides of the door.
2. Detach and remove broken spring
Be careful when detaching the springs. They are flexible and could wound tight. Detach the spring from the mounting points first before releasing the end that attaches to the safety cable. Inspect other parts like the pulley and cables to ensure they are still in good working condition before proceeding.
3. Buy identical spring from local hardware store or garage door dealer
Take the removed spring to your local hardware store or overhead garage door dealer. It is important that you go with the spring you just removed to ensure you buy the right spring with identical length, diameter and wire gauge. Using the wrong spring could cause your garage door to malfunction. Confirm that the spring ends on the new springs are identical to the old spring you are replacing. Buy two springs and replace both on the same day. This helps balance the load on the springs.
4. Install the new garage door spring
Using the spring still attached to the other side of your garage door as sample, install the new garage door spring. Ensure you use the same measurement as the old spring when installing the new spring. The new spring should not stretch when the garage door is fully opened and both door pulleys should not touch when the door is closed.
5. Reattach safety cable
Reattach the safety cable on the other side of the spring when you are done installing the spring. Be sure the spring is properly installed to avoid damage to your garage door during operation.
6. Replace other spring
Go to the other side of your garage door and following the steps above, remove and install the other door spring. Use the spring you installed earlier as a guide for the second installation. Do not forget to reattach the safety cables.
7. Remove garage door support
Once you are certain the springs on both sides of the door and safety cables are installed and attached properly, carefully remove the garage door support. This depends on the type of support you applied above; piece of lumber, C-clamps or locking pliers.
8. Complete readjustment if necessary
Adjust your garage door as needed. When all necessary adjustments is complete, plug your garage door to the power source and test your door. Your garage door should function without problems if all steps above were completed properly.