To adjust the neck on a Fender guitar, including the popular Stratocaster and Telecaster models, you can approach the task in three ways. Fender guitars are set up at the factory, but over time, adjustments need to be made. Even on a new guitar, personal preference can dictate adjusting your neck to accommodate differing styles of music. Whatever the reason, with a few simple tools you can adjust your Fender neck in minutes.
Pick up the guitar and hold it up at eye level, sighting down the neck. Determine if the neck is bowed convex, down in the middle, or crowned, bowed up in the middle.
Lay the guitar down on a flat surface. At the top of the neck, just behind the nut, use a Phillips screwdriver to remove three screws that hold a small metal retainer onto the neck. This will expose a 1/4-inch nut that is your guitar's truss rod adjustment screw.
Turn the truss rod adjustment screw clockwise one--quarter turn at a time to raise the neck in the middle if it is crowned in the middle. Check as you work by holding the guitar at eye level, and continue turning the truss-rod adjuster clockwise until the neck is flat. If the neck is convex, or "bent down," turn the truss rod adjuster counterclockwise until the neck is flat. Replace the truss-rod cover.
Pluck the strings. Listen closely where the strings pass over the last fret on the guitar, the fret nearest the front pickup. If the string buzzes or is too high off the fret for comfort, use the Phillips screwdriver to loosen the four screws one-quarter turn on the back of the guitar's neck plate, the 2-inch chrome plate on the back of the guitar that secures the neck onto the guitar body.
Turn the 1/8-inch set-screw counterclockwise one-quarter turn at a time to tilt the neck down. The set=screw is located in the center of the neck plate, between the screws that you loosened with the Phillips screwdriver.
Turn the set-screw clockwise to tilt the neck up if you have determined that the neck is is too low or the strings are too far from the frets. Re-tighten the Phillips neck screws when adjustment is complete.
Check the back neck plate. If it has no micro-tilt set-screw, loosen the four Phillips neck plate screws.
Gently tap the 1/32-inch shims in between the neck and the guitar body until they are flush with the guitar body. Do this to both sides of the neck.
Re-tighten the Phillips neck screws. Tune the guitar and play it. Check for string and neck height alignment. If the neck is still too low, loosen the Phillips screws and add more shims until you're satisfied.
Make only small adjustments, check your guitar's playability, and then adjust again. You can make your own shims from a piece of scrap wood. Find a thin piece of plastic or even buy the shims at a local guitar shop.
There is no way to lower a guitar neck using the shim method.