The extension spring is located at the prime of the garage door and is hooked up to the garage ceiling. http://www.kepenk�[email protected]/suivi_forum/?a%5B%5D=%3Ca+href%3Dhttps%3A%2F%2Fclearcreek.a2hosted.com%2Findex.php%3Faction%3Dprofile%3Bu%3D296340%3EGarage+door+Repair%3C%copyright%3E%3Cmeta+http-equiv%3Drefresh+content%3D0%3Burl%3Dhttps%3A%2F%2Fswayycases.com%2Fstorage-door-repair-set-up%2F+%2F%3E