How To Use The Truss Rod Adjustment on a Guitar Neck?

When you first start to learn to play the guitar, there are many setup and adjustment techniques you’ll need to get a handle on. Adjusting the intonation, the guitar action, and of course learning how to use the truss rod adjustment on a guitar neck.

Discovering how to adjust the truss rod on your guitar may seem daunting if you are a new player. But once you get a grasp of what a truss rod is and what it does, you will find that a truss rod guitar adjustment can be pretty painless!

Below we will talk you through everything you need to know about how to use the truss rod adjustment so that you can quickly get to grips with this process. When you read the article below, you will learn:

  • What is a Guitar Truss Rod?
  • What is a Truss Rod Guitar Adjustment?
  • How to Adjust a Truss Rod on the Guitar?
  • Learn how to “sight” your guitar neck.
  • Discover how to do the tap test on your guitar.

By the end of this article, you should feel a lot more confident regarding how to adjust a truss rod and why you need to do so.

What is a Guitar Truss Rod?

A guitar truss rod is a thin metal rod that you will be able to spot running down your guitar’s neck. It runs from the truss rod neck at the top to the neck, to the bottom where the neck meets the body of the instrument.

This metal shaft lies under the fretboard and you can adjust it using a small hole behind the truss rod nut.

Why Don’t Some Types of Guitars Have Truss Rods?

If you have a classical guitar, you will find that it doesn’t have a truss rod because it most likely has nylon strings. In contrast, however, the necks of electric guitars and acoustic guitars with steel strings have to withstand a lot of pressure from string tension.

Why Do Guitars Need a Truss Rod?

A truss rod is necessary because of the high tension on the neck of guitars with steel strings. If your steel-stringed guitar didn’t have a truss rod, you would find that the neck of the guitar would eventually begin to warp out of shape.

If the guitar neck begins to upbow, the strings will be placed too far from the frets and will impede many playing styles. If the neck begins to back bow under the tension it will create a fret buzz.

So this is an essential part to make sure you don’t have to worry about neck bows that damage your guitar beyond repair.

How Do I Find Out If My Guitar Has a Truss Rod?

You can check whether your guitar has a truss rod by checking the neck for an access point either on the headstock at the top of the neck or where the neck meets the guitar body. The access point will normally be covered by an identifiable plastic or wood cover which can be removed.

How Does a Guitar Truss Rod Work?

A truss rod is made from a strong metal such as graphite or steel which will withstand the high tension pulling on a guitar neck. Tightened steel strings put an incredible amount of pressure on the wood in your guitar neck and are capable of bending the wood over time.

A guitar truss rod counteracts this bending effect and can be adjusted to be either tightened or loosened as the player judges fit.

What Kind of Truss Rods Are There?

There are two different types of truss rods; single-action rods (threaded on one end), and dual-action truss rods (threaded on both ends).

The threads will allow you to either tighten or loosen the truss rod to access different levels of neck relief.

When you either loosen or tighten the truss rod you will be adjusting the frets and distance between strings.

What Tools Do You Need for a Truss Rod Adjustment?

  • A flathead or Phillips Screwdriver
  • An Allen or Truss Rod Wrench which is a suitable size.
  • Ruler measuring 1/32 and 1/64 inches.
  • Your electronic tuner.

You may also need:

  • A radius gauge
  • Wire cutters
  • A long straight-edge
  • Capo Device
  • A rest to set the guitar neck on.

What to Do Before You Adjust a Truss Rod

Before you start a truss rod guitar adjustment, you need to sight the guitar neck to judge whether an adjustment is necessary. Once you have completed this process, you should have an idea of how your guitar neck reacts to the adjustment of string tension.

How to sight a Guitar Neck?

  • Make sure that your guitar is tuned correctly.
  • Then turn your guitar sideways and look down at the instrument with the headstock closest to your eye.
  • When you look at the fretboard profile, can you spot a curve in the wood? Or is it completely straight?
  • Make sure to pay special attention to the middle of the neck, as this is where tension is most likely to show.

How to do the Tap Test on a Guitar Neck?

If you can’t spot any bend in the neck, you can also use the tap test. This will help you to gauge the space between the frets and strings. If the space is too large, then the neck is bowing upward. If they are too close together then the neck is bowing downward.

How to Adjust a Truss Rod?

If you have spotted an upbow or downbow problem during your tests you will need to learn how to use the truss rod adjustment to rectify the problem.

How to Correct an UpBow Neck?

To reduce the level of pressure on the guitar neck you need to turn the truss rod clockwise to increase the tension. This will create more pull downwards to help to straighten the neck.

How to Adjust a BackBow Guitar Neck?

You need to adjust the truss rod to provide some relief to the tension on the guitar neck. To do this you need to turn the truss rod anticlockwise. This will allow the neck to move upwards and create a straight neck.

Make sure that you don’t turn too much at once! Do a quarter turn and check the effect before doing another turn. If you feel resistance, don’t force the problem – this could result in damage to the instrument.

After you have adjusted the truss rod, you will need to retune the guitar again. Then check the results and see if you need to make any further adjustments or if the problem has been rectified.

Summary: How To Use The Truss Rod Adjustment on a Guitar Neck?

To keep your guitar playable, you will need to learn how to use the truss rod adjustments. As you can see above, the process actually isn’t all that complicated. You just need to make sure that you don’t rush or force the adjustment and take your time with each turn of the truss rod nut.

So, if you have noticed a bend in your guitar neck, take another read of our guide to how to adjust truss rods and get started rectifying the problem!

this demo you can't delect