This page gives a brief introduction to how garage doors operate.
All sectional(most residential doors – composed of several “sections” as opposed to one-piece or commercial roll-up type doors) garage doors use springs and cables to pick up the weight of the door, and rollers and hinges to allow the door to travel up and down through the door tracks. An electric opener with remotes can be added to the door to help the springs lift the door so you don’t have to do it manually.
Rollers are attached to hinges on the door sections and “roll” along in the tracks. The rollers can be made of steel or plastic. The steel rollers use ball bearings, and plastic rollers either use ball bearings or simply rotate directly on the shaft. Higher cycle rollers are available, but it is rarely cost effective to pay 5 times more money to receive high cycle rollers, especially since rollers rarely wear out and never do all of the rollers wear out at the same time.
Cables are attached to the bottom bracket or the bottom roller and the spring system, which is tensioned to pick up the weight of the door. If a cable breaks, it needs to be replaced carefully since the cable on the other side will still have tension holding the spring. Doors will not raise and lower evenly without both cables properly installed.
All sectional doors use springs to raise and lower the garage door. All springs have a limited service life and will need to be replaced eventually, depending on the usage (number of cycles it goes up and down). There are 3 types of springs available.
Torsion spring: located on a bar above the top of the garage door. This type of spring needs to be replaced by a trained professional, since it has a lot of tension on it and requires special winding bars. The only service that a homeowner should perform would be to put oil across the top of the spring which allows the oil to run between the coils and may help the spring to last longer. Higher cycle springs are available to purchase, but it is not always cost effective to purchase them to use on an older garage door.
Stretch spring: located above the track, one on each side of the door. These springs work independently of one another, which can allow the door to wobble back and forth as the door is traveling up and down. These springs have the most tension when the door is down, and when they break, the spring has the potential of damaging anything in its path as it flies away. Safety cables can be used to prevent this. This spring system requires 4 pulleys for the cables to travel around, and when these pulleys age, the bearings can become wobbly and cause the door to have trouble going up and down smoothly.
TorqueMaster spring: invented and used only by Wayne Dalton Door, Co. This spring is concealed inside a tube that is mounted above the garage door on the header. This is a safer spring because home owners cannot be injured by this spring if they try to service or replace their own broken spring. This spring is wound with a drill, ratchet, or wrench. No oiling is required.