AN OVERHEAD GARAGE DOOR HINGING SYSTEM HAVING A SPRING FASTENER FOR ADJUSTABLY COUPLING COUNTERBALANCE SPRINGS TO A POWER ARM. THE SPRING FASTENER INCLUDES A PAIR OF SIDE PLATES BETWEEN WHICH THE POWER ARM IS PIVOTABLY MOUNTED THROUGH ONE OF A PLURALITY OF HOLES IN THE POWER ARM. A PLURALITY OF OPENINGS ARE SO SPACED ALONG THE SIDE PLATES THAT EACH OF THE OPENINGS ARE ALIGNED WITH A DIFFERENT ONE OF THE HOLES IN THE POWER ARM AT ONE POSITION OF THE HINGING SYSTEM, WHEREBY THE POINTS OF ATTACHMENT OF THE SPRINGS TO THE POWER ARM MAY BE CHANGED WITHOUT DISCONNECTING THE SPRINGS. THE COUNTERBALANCE SPRINGS ARE CONNECTED TO THE GARAGE STRUCTURE BY MEANS INCLUDING A SPRING-CONNECTING MEMBER AND A SLOTTED MOUNTING BRACKET WHICH ARE ADAPTED FOR ACCOMMODATING A TENSION-ADJUSTING TOOL FOR REPOSITIONING THE CONNECTING MEMBER, AND THEREFORE ADJUSTING THE TENSION OF THE SPRINGS. A SPRING SPREADER, HAVING SPRING-CONNECTION LUGS MOUNTED ON A SHAFT SO AS TO CONVERT ROTATIONAL MOTION OF THE SHAFT INTO LINEAR DISPLACEMENT OF THE LUGS, IS PROVIDED FOR CONVENIENTLY INSTALLING THE COUNTERBALANCE SPRINGS. A MOUNTING MEMBER POSITIONING TOOL IS FURTHER PROVIDED FOR RELEASABLY ENGAGING ONE LEG OF A MOUNTING BRACKET OF THE HINGING SYSTEM, SO THAT THE GARAGE DOOR MAY BE DETACHED AND REINSTALLED WITHOUT DISCONNECTING THE SPRINGS FROM THE SYSTEM.