The one time just one may need a complete substitute is when 1 has large useful or cosmetic damage. As an example, if a single forgot to open up the door and backed the vehicle into it. But, garage doorway gurus can restore slight cosmetic harm to the doorway, like http://tysontmyku.blogofoto.com/19510478/10-telltale-indications-you-need-to-get-a-new-garage-door-off-track-repair