Every guitarist should learn to do truss rod adjustments for
him or herself. There really isn't much danger if you use caution. Most new
guitars come with a wrench for you to use for that purpose. If you are buying a
guitar and it doesn't come with one, ask the salesman for one. They're usually glad
to give you one for free.
The truss rod adjusts the amount of bow or "relief" in the neck. The neck
should have a little bit of relief and not be perfectly flat unless it's a nylon string
classical guitar. When you pick, pluck, or strum a string, the maximum movement is
in the middle between the nut & saddle of the guitar. Depending on your playing
style, you may want more or less relief.
In my Tips 82 & 102, I mentioned this stuff but it doesn't
hurt repeating...
a.) If the string buzzes when you fret on the bottom 6 frets, the truss rod may be too
tight.
b.) High action up by the sound hole end of the neck may mean that the truss rod
is too loose and/or the bridge/saddle setup is too high.
c.) Check the concaveness of the neck. With your left index finger, push down on
the Bass E string on the first fret like you're playing a F. With your right index finger,
push down on the Bass E string at the 12th fret like you're playing a high E. Now look
between the bottom of the Bass E string and the top of the 6th fret. You should be able to
see a very slight gap. Just enough to see some light. If you can't
see any light and/or the string is touching the fret, the truss rod is too tight. If
there's a larger gap than the thickness of a business card or match book cover, the truss
rod may be too loose for you.
d.) If the relief of the neck checks out alright using step "c.",
but the strings are uncomfortably high, DON'T try to lower them by tightening the truss
rod. You might break it. In some cases the problem is best fixed by lowering
the height of the saddle instead.
The main cautions to observe when adjusting the truss rod are...
a.) Make small adjustments each time. (1/8th turn)
b.) Look at the results of each adjustment before turning again. If the opposite is
happening than the desired effect, you're probably turning it the wrong way (see below).
If it's going the right way, don't go too far.
c.) Be patient. It may take overnight for the full result of the adjustment to show
up.
d.) Don't apply excessive force. If the nut doesn't turn with a reasonable amount of
force, you could break the rod. This is very expensive to repair!
Now finally : )
Whether the nut for the truss rod is at the tuner end of the neck or in the sound hole, it
is tightened to lower the string clearance "relief" by turning clockwise when
you are facing the adjustment nut. Turn counterclockwise to increase the string
clearance. Remember, 1/8 turn! If the nut is at the tuner end of the neck,
there is a small cover to remove first.
As usual, if you have any problems or questions until you learn - go see a pro!
If you have old Martins like mine or a nylon string , there's probably no adjustable truss
rod at all. Mine have never given me any problems but if these necks go out, you'll
need to see a repairman or send it to the company.
Gman ( o )==#