How to Adjust a Guitar Neck With the Adjustable Truss Rod

The neck of most guitars are adjustable. The adjustable rod both strengthens the neck and facilitates adjustment of a bowed neck. Because all guitar necks are subject to great stress as a result of string tension and climatical change, there are times when a neck will take on a slight bow (warp, neck hump). This will rarely occur. However, if it does, there is no cause for alarm if you follow the procedure below for proper correction.

Headpiece Type of Adjustable Truss Rod

Loosen 3rd and 4th strings (do not remove strings from guitar). Pull loose strings to one side so free access to nut cover can be obtained.
Remove cover so neck adjustment nut is exposed.
Sight down the neck from the top in order to see just how much of a bow or hump the neck has taken. Note: Hold the neck up at eye level and sight along the edge of the fingerboard on both treble and bass sides.
If neck is bowed, tighten adjustable nut (turn wrench clockwise).

Neck with “bow” in the middle, will cause bad action and impair intonation.
If neck has hump, loosen adjustable nut (turn wrench counterclockwise).

Neck with “hump” in the middle, will cause string rattle and false tones.
Place guitar wrench on adjustment nut and turn very gently (small fraction of a turn at a time). Keep checking the neck as you proceed with each nut turn. Once the neck is straight give the adjustment nut a very slight added turn to compensate for the tension the 3rd and 4th strings will add once they are replaced and tuned.

Special Note: When making this adjustment, it is best to place a straight-edge on the frets to assure a perfect adjustment. Be careful not to tighten the nut too much (ie. when it becomes hard to turn), because it could result in stripping the threads or perhaps even breaking the truss rod.

End-Of-Fingerboard Type of Adjustable Truss Rod

On certain models of guitars, adjustment of the truss rod is made at the lower end of the fingerboard. However, the procedure of adjustment is the same as above. Follow the pattern of correction as outlined in Headpiece Type of Adjustable Truss Rod.

If there is buzzing after you are certain the neck has been straightened, locate the fret at the playing position that causes the buzz. Lower the fret by gently tapping with hammer. If necessary, file the fret down.