Repairing a sagging gate with a cable and turnbuckle is an inexpensive project. Anti-sag gate-repair kits include connecting hardware, steel cable, a turnbuckle and two cable clamps. The simplest gate-repair kits use screw hooks to attach the cable and turnbuckle to the gate frame. Without removing the gate from the gatepost, you can tighten the frame, using common home-repair tools. This quick project can prevent your gate from dragging, and allow the hinges and latch to operate properly.
Close the gate. Place scrap lumber under the gate to raise it to its normal position, aligning the latch so it functions properly. Using a drill bit that is slightly smaller in diameter than the threaded shanks of the screw hooks in the anti-sag kit, drill two pilot holes into the vertical stiles of the gate frame. One hole should be about an inch beneath the top rail of the hinge side and the other, about an inch above the bottom rail of the latch side. Screw the screw hooks into the pilot holes until the curved portions of the hooks meet the frame.
Attach the cable to the turnbuckle by placing a cable clamp onto one end of the cable. Thread the cable through an eye-screw on the turnbuckle, and then back through the cable clamp, leaving about 2 inches of the end of the cable protruding from the clamp. With a screwdriver, tighten the clamp so the cable will not slip. Fully expand the turnbuckle by turning the eye screws on the ends.
Place the eye screw of the turnbuckle that is not attached to the cable onto the screw hook on the hinge side of the gate. Thread the second cable clamp onto the free end of the cable. Hook the cable on the screw hook on the latch side of the frame. Thread the free end of the cable back through the cable clamp, forming a loop of cable attached to the screw hook in the gate frame. Pull the free end of the cable to tighten it as much as possible. Slide the cable clamp so it is close to the eye screw. Tighten the cable clamp with a screwdriver.
Turn the turnbuckle clockwise to remove slack from the cable. As tension increases, you will have to use an adjustable wrench to continue tightening the turnbuckle. Continue tightening until the latch side of the gate is in the proper position for the latch to work properly. Trim the excess cable with wire-cutting pliers and remove the scrap lumber from beneath the gate.
Some gate-repair kits include specialised hardware for attaching the cable to the gate frame. Refer to the manufacturer's instructions for installation. If your gate begins to sag over time, you can tighten the cable by turning the turnbuckle.