Extension springs are under extreme tension when the door is down or in operation.
Your door is closed for the majority of the time and when the door is in the down position the springs are fully charged and at their most dangerous.
When, not if, a cable or springs breaks and safety cables are not present the charged spring becomes a potentially deadly projectile.
I have seen instances of an extension spring actually traveling through garage walls.
Unfortunately I have done repairs after someone was hurt by a flying extension spring.
I cannot stress enough the need of having safety cables on any and all extension spring garage doors.
THIS IS AN EXTENSION SPRING
NOTE THAT THERE ARE NO SAFETY CABLES INSTALLED ON THIS SPRING
Here is our Extension Spring SAFETY CABLE KIT
Installing a safety cable is a simple process.
First, open the door fully and place a clamp or vice grip under each bottom roller to prevent the door from closing. UNPLUG THE GARAGE DOOR OPENER!
Run one end of the cable through the back hanging like this
Next, run the cable through the spring
The cable needs to run to the OUTSIDE of the clevis pulley on the other end of the spring
Next, install the eyebolt into the door jamb / frame above the stud pulley (front pulley mounted on the top of the door track)
then loop the cable through the eye bolt. Pull the safety cable tight and install the cable clamp to hold the cable in place.
Obviously repeat this process on the other spring.
Placing or leaving the door in MANUAL OPERATION AND LEAVING THE GARAGE DOOR OPENER UNPLUGGED, remove the clamps from the door.
Standing in the center of the garage door, slowly close the door being diligent to observe the movement of the spring.
We want the spring to function as if the safety cable were net even there.
If there is any interruption of normal spring travel, stop the downward movement of the door and open the door fully,
re install the two clamps under the bottom rollers and adjust the safety cables as needed.
The only issue that may arise is if you have ran the cable on the wrong side of the pulley as it exits the front of the spring.
Again, the cable needs to exit the spring on the OUTSIDE of the pulley.
After any adjustments, follow the above procedure with the door in manual operation SLOWLY closing the door.
Open and close the door a few times and as long as the springs are functioning unobstructed this is another job done.
You have just prevented what could be a tragedy.
You and your family are now considerable safer, your car and other items in your garage are no longer targets for an errant spring.
Life is good!