Yes, you can replace a garage door without changing the rails. Most vehicle doors come with a pre-cut header that can be set into the existing rail system. This header will fit snugly into the opening, so it is not necessary to change out the rails.

Normally, a trackless garage door is used for garages with limited interior spaces. When it is activated, the trackless garage door will raise itself, fold in half, go under your garage ceiling, split into two parts, and then the lower section of the garage door will slide under the upper section.