The contraction and stretching of the garage door extension springs make the opening and closing of the door possible. This makes these components particularly important for the operation of the system. Without them, the unit will simply not be able to function, and it may pose a great threat to people and property as well.
Less often, when the unit is particularly heavy, more springs can be included in the set. In the classic case, there is one spring above the left horizontal track and one above the right one. The back end of each component is connected to the angle iron which is also responsible for holding the track into place. This is done with the use of a special bolt. The other end of the spring is attached to a pulley with the help of a fork component. There is a cable going over this pulley and over another one that is attached to the bottom end of the door.
The springs are stretched while the door is in closed position. They are loaded with tension corresponding to the unit's weight. This is how they actually hold the door in place. When you press the button on the clicker to open the door with the opener, the electric device starts pulling it up. The energy held by the springs is released as they contract. It is applied to the pulleys and then to the lift cables. This is how the door gets opened. Most of the energy necessary for this is provided by the springs.
Given that they are stretched and loaded with energy, the garage door extension springs should never be adjusted or repaired by someone without special technical skills.