The main benefit of changing your garage door system from a one spring, into a two spring system is first and foremost SAFETY. If a torsion spring breaks, there is nothing supporting the door. Generally the opener is not going to be able to support the door by itself. This means if the spring breaks while the door is opening then there is nothing to keep it supported and open. It then comes down with a BANG. And this can lead to serious injury or even fatalities. The other reason to uses a two spring system is cost.. The benefit of a two spring torsion system allows less wear and tear on the torsion system, which saves you the consumer, more money in the long run. You can often buy two 40,000 cycle springs for less than one 60,000 cycle spring, so you get both more use for a lower cost.
The reason some garages only have one spring is that the developers, in a nutshell are just looking to save a few dollars…. literally a few dollars. And it also allows the same developers to sell you another spring down the road.
The reason a spring breaks is pretty simple they only have a set cycle life, over time the material breaks down and eventually stops working, or breaks completely. Every piece of your garage is made to have a specific cycle life.
The steps to installing a second torsion spring are surprisingly simple. Now these instructions are giving under the assumption that you are doing this after your single spring system broke its spring.
STEP 1) First you should unplug your opener, then disengage it from the door, vice grip the track to keep the door in place when you wind the spring. You will want to loosen both the winding and stationary cones from the shaft and bracket, as per there is no spring or tension applied to the spring.
STEP 2) Mark the shaft and cable drums so you can see where they need to be when replaced. Then loosen the drums and slide the shaft out of one end of the bearing plates and remove the broken spring. Then you simply slide the new spring in making sure it is the same wind. After sliding the cable drum back on the shaft you reinsert the shaft into the end bearing plate.
STEP 3) Now you take the second spring slide it on the shaft and rinse wash and repeat the previous instructions.
STEP 4) Then you reset the cable drums and install the cable, re secure the stationary cones together at the spring anchor bracket.
STEP 5) Now all you have left is to wind the springs, secure the setscrews to the shaft, and reengage the plug on the opener.
All in all just a few extra steps to give you and your family more value, and security.