Tuning pegs, or tuning machines, tighten and loosen the strings on guitars for tuning adjustments. The pegs are typically divided onto both sides of the headstock of an acoustic guitar and often aligned in a single row on one side of an electric guitar headstock. Quality tuning machines hold the tension on guitar strings to retain tuning longer. Replace tuning pegs that are damaged, or upgrade for better performance.
Remove the strings from the guitar by loosening the tuning pegs until the strings wind completely off the posts. Use a string winder wrench to expedite the process. Pull the ends of the strings out of the holes in the posts and remove the pins from the saddle to free the strings at the other end.
The tuners may be affixed to the back of the head with one or two tiny screws. If any are present, remove the screws from the back covers of the tuning machines with a small Phillips screwdriver. A few tuning machine makers have eliminated such holding screws.
Remove the nuts around the posts at the front of the guitar head. Fit an adjustable wrench or appropriate-size socket wrench over the nut and loosen with counterclockwise turns. Once the nut is free, the post will slip through the hole in the headstock and come off with the enclosed tuner body.
Push the posts of the new tuning pegs through the holes in the guitar headstock. Check for alignment of the holding screw holes in the back of the headstock. Fill the old holes with wood putty and allow two hours' drying time if the holding screw holes on the new tuners do not line up with the existing holes in the wood.
Fit the nuts over the posts and tighten snugly by hand. Align the holes in the back if the old holes match up with the new tuners. Position the screw holes away from the putty-filled spots if they do not align. Tighten the nuts securely with an adjustable wrench or socket wrench while holding the tuning pegs in place.
Put the small holding screws through the screw holes in the tuners. The screws can use the old holes if they aligned properly with the new tuners. Create new holes in the wood if necessary by driving the points of the screws into the wood with forceful turning pressure. These tiny wood screws will sink into the wood without disturbing the headstock. Put fresh strings on the guitar once all the tuning pegs are secured.
Remove the strings completely by loosening the pegs, slipping the top ends out of the post holes and untying the saddle ends. Push ball end guitar strings through the saddle tunnels.
Unscrew the hub screws in the centre of the gear wheels with a Phillips screwdriver. All three gear wheels must be removed from a side before the peg strips can be removed.
Remove the holding screws on the strips holding the pegs. Both strips will be secured with three or four screws. Pull out the horizontal tuning posts. When purchasing replacement pegs, bring one of the strips to the store to ensure alignment of the horizontal tuning posts, unless you are buying the exact make and style of tuners.
Install the new tuning pegs. Insert the new horizontal tuning posts. Push the posts through the side holes in the headstock with the threaded screw holes facing out. Secure the strips of the new pegs on either side of the headstock. Line up the holes for the tuning posts and check the alignment of the holding screws. Fill the old screw holes with putty and wait two hours for drying if the holding screws do not line up. Use the old holes to secure the screws if they align. Force the small wood screws into the headstock for new holes if necessary.
Put on the new tuning gears. Place the shafts of the gears into the side holes and slip the gear cranks into the spiral grooves of the tuning pegs. Put the hub screws in the centre and tighten securely. Install a new set of guitar strings.