Learning how to fix a twisted guitar neck is straightforward. You have two choices: attempt to turn the neck back or replace the part. Consider any other problems the neck may have before deciding whether to fix the twisted neck. If the board is thinned or the frets are falling off, it may be worth changing out the neck as opposed to fixing the twist. However, if twisting seems to be the only issue, adjusting the truss rod may correct the piece and straighten the neck back into shape.
- Look into the sound hole, towards the neck. Check for a hex nut sitting on the base of the hollow portion at the opening of the neck.
- Check near the nut on the front of the headstock if you do not see the hex nut in the sound hole. There may be a piece of plastic or wood attached to the headstock with screws. This piece probably covers the hex nut that retains the truss rod.
- Turn the guitar over and look for the hex nut on the back of the instrument. This is a common location for twelve-string guitars. Use a hex wrench and turn the hex nut a quarter of a turn clockwise.
- Lay the guitar down and view the neck at eye level. As the truss rod tightens, it should twist the guitar's neck around. If the neck is still not straight, turn the hex nut another quarter of a turn. Continue this process until the neck sits flat.
Severely twisted guitars will need to have new necks installed. Wood likes to change shape and will do so regardless. A badly twisted neck will continue to twist. It is just the nature of wood. It is better to replace the piece and save the effort and cost of trying to fix it.