The other thing to remember about garage springs is that they can and do break spontaneously with extreme force causing parts to fly off in all directions. The springs should be replaced on a regular basis. We've lived in our house for a long time, and twice we've had them break while the door was closed and idle. The first time it occurred we heard a tremendous racket in the garage and upon inspection, we found that the spring had broken lose and whipped around causing most of the noise as it bounced off of walls. The cause of the failure was the hook at the end of the spring breaking. It shot off denting a car. I'd hate to think what could have happened if someone had been in the garage at the time. We learned that you can and should buy cables that run inside the spring so upon failure, the larger part will at least be restrained.
