the other hand, it may be that your garage isn’t doing its part. An overhead sectional door can weigh several hundred pounds, and without a little mechanical help it might as well be locked shut. Garage doors that roll away overhead use springs to counterbalance their weight.
The spring system is either a torsion assembly mounted over the top edge of the door, or a pair of springs, each running along the garage ceiling next to a horizontal length of door track. When the springs get weary after years of use, the door gets harder to lift. While new springs are a sure way to lighten the load, they won’t do much to improve your mood as you pull into your driveway on a stormy night. For the ultimate in convenience, there’s only one solution—an electric garage door opener. Fortunately, installing new springs and a door opener are straight-forward jobs requiring only basic tools and a free weekend or two.
This project was originally published in the October 2002 issue of Popular Mechanics. You can find more great projects at Popular Mechanics DIY Central.
Step 1: Spring Replacement
Most residential garage doors are linked to the springs by cables, but some heavier doors, like ours, have chains. Also, some doors have double springs. The cables or chains travel from the bottom of the door to a stationary pulley at the top of the track frame, then to a pulley attached to the spring, and finally to an S-hook attached to the track frame near the stationary pulley. With the load off the springs and the door secured, find the S-hook on one side, pull on the cable or chain to release the load on the hook, and remove the hook (Fig. 1).
Repeat the process for the other spring. With one end of each spring free, move to the opposite ends and remove either the S-hooks or U-bolts that secure the springs to the rear track supports (Fig. 2). The weight and size of the door determine the correct replacement springs. To find springs, contact the manufacturer of your door, or a supplier of garage door equipment. Check your old springs for an identification tag. If you don’t find a tag, you’ll need to weigh your door by removing the C-clamps and lowering it onto a bathroom scale. Bear in mind that a large door can weigh a few hundred pounds and the effort required to support it increases dramatically as it’s lowered.
Be extremely careful. Have someone on hand to help, and use temporary supports on which to rest the door as you lower it in stages. We lowered our door onto sawhorses, and then used a 2 x 4 as a lever to rest it on the scale (Fig. 3). With the proper springs on hand, remove the pulleys from the old springs and install them on the new springs (Fig. 4). Then, secure the opposite ends to the rear track supports, pass the cables or chains through the spring pulleys, and secure the chains to the front support frame with the S-hooks. To reduce the danger of a breaking spring, run 3⁄16-in. steel cable through each one and attach the cable ends to the frame with cable connectors (Fig. 5).
Step 2: Installing an Opener
The opener comes with a powerhead, a boom that contains the chain drive, mechanical linkages, sensors, controls and all necessary wiring. To install this opener, first lay the powerhead on the floor, slip the drive end of the boom over the powerhead shaft (Fig. 6), and secure the boom with screws. Find the exact center of the door, mark it on its top edge, and extend the mark onto the door-opening header. Partially open the door and measure its highest point of travel over the floor (Fig. 7). Then, with the door shut, add at least 21⁄2 in. to this to get the boom location. Mark this height at the centerline on the header (Fig. 8).
Position the U-shaped header bracket at the height and centerline marks and secure it with lagscrews (Fig. 9). Then, connect the free end of the boom to the bracket with a pin and locking clip (Fig. 10). Lift the powerhead onto a step-ladder to bring it close to its final position (Fig. 11). Place blocks under the powerhead as necessary to level the boom. To position the powerhead between the door tracks, open the door and align the center of the boom with the centerline mark on the door.
Then, secure the powerhead to the overhead framing. We used perforated angle stock bolted to the powerhead and extending up to the roof crossties (Fig. 12 and 13). With the door shut, install the door bracket at the top of the door on the centerline (Fig. 14). Link the lower L-shaped door arm to the door bracket with a pin and cotter pin (Fig. 15). Attach the upper control arm to the boom carriage (Fig. 16). Unlock the carriage from the chain by pulling down on the release lever, and slide the carriage so the two arms can be bolted together (Fig. 17). Tie the release cord to the carriage lever.
Step 3: Opener Controls
Strip 1⁄2 in. of sheathing from the system wires, and connect the sensor to the source (Fig. 19). Then, run wire from the source to the powerhead. Secure all wiring with staples. Attach wire to the terminals on the back of the manual control panel, and screw the panel to the wall near the door at a height where small children can’t reach it (Fig. 20). Then, run this wire to the powerhead. Follow the instructions that came with your unit to connect the wires from the source module and control panel to the powerhead (Fig. 21). Our unit came ready to be plugged into a receptacle.
Check to see if local building codes require the opener to be wired directly to the electrical panel. Move the door until the carriage is under the connecting link in the chain. Push up the lever to engage the carriage with the chain. Climb up to the back of the powerhead and press the limit switch to open the door. Release the switch when the door is at its full open position. Press and release the limit switch when the door reaches the closed position. With the rough limits set, check and adjust the open-force and close-force settings. Next, fine-tune the open and close positions by adjusting the screws in the limit- adjustment slots at the back of the powerhead. Test the contact-reverse system by placing a 2 x 4 under the open door. Lower the door onto the board. If the door does not reverse automatically, adjust the close-force setting.
Step 4: Finishing Touches
Before you leave your garage door for another season, check the seal under the door edge. If it’s deteriorated, use a pry bar to remove all the old nails (Fig. 22). Then, use galvanized nails to secure a new seal (Fig. 23). Finally, clean the door tracks and lubricate all metal rollers.