Truss Rod Frequently Asked Questions If you wish to tighten the truss rod, you merely need to loosen your guitar strings before adjusting the truss rod. Tightening the truss rod adds tension to the strings, which might cause issues. You do not need to loosen your strings if you wish to loosen your truss rod. The term "truss" comes from early stringed instruments, like guitars and violins, where it is used to describe the structure that holds the neck and body together. On a guitar, the truss rod is a metal rod inside the body of the guitar that controls the tension in the neck and shoulder joints. The goal is to find a setting that keeps the guitar in tune, but doesn't cause it to crackle or buzz when you play. Each string on your guitar is held under slight tension from its tuning peg to the top of its gauge (diameter). This helps to keep the string in tune, but also makes it possible for you to hear any irregularities in pitch when you play. To adjust the truss rod, first remove the strings. Then take off the nut at the base of the fretboard on the guitar's neck and slide it away from the body. Finally, lift up the saddle located just behind the nut and move it toward or away from the body to adjust the tension on each string. You should only need to adjust the truss rod once or twice during the life of your guitar.