Adjusting the truss rod on a guitar is one of the most important aspects of maintaining your instrument. It’s an easy task that doesn’t take much time, but can make a big difference in the sound and playability of your guitar.
In this article, you’ll learn how to adjust your guitar’s truss rod, do a tap test to check it, and get some tips about what to be aware of when making adjustments.
So read on for everything you need to know about how to adjust your truss rod!
What is a truss rod
A truss rod typically consists of a metal bar running along the length of a guitar neck that can be adjusted to help it resist string tension. This bar is usually steel, but other materials like graphite may also be used.
Adjusting the truss rod affects three main aspects: neck relief, action, and intonation.
Proper adjustment can help you customize your guitar’s setup to play optimally regardless of weather or player style changes.
How to adjust the truss rod on a guitar – Step-by-step guide
Now that you understand what a truss rod is, you can learn how to properly adjust it. Just follow these steps, and you’ll be ready in no time.
Prepare the tools you need
To get the job done right, you’ll need the proper tools.
- Two capos: to hold down strings while making any adjustments to the truss rod.
- Feeler gauges: for setting the correct string action on your guitar.
- A small screwdriver: for removing a truss rod cover before adjusting it.
- A hex key or wrench: to make accurate truss rod adjustments; make sure that it fits the truss rod nut before starting.
All these items should be ready before attempting any adjustment so that you can work smoothly and efficiently.
Check the Neck Relief
To check the neck relief make sure to:
Tune your guitar
Tighten your strings and get the right tension to ensure your neck has the right amount of curve.
Use the same strings you already play with and tune your guitar as usual. Different gauges may require additional adjustments.
It’s important to keep the strings on when adjusting your truss rod.
Taking them off can make your adjustment inaccurate.
Over time, the pressure from the strings can cause an increase in bowing. This means that even if you had good neck relief when you first bought it, you’d need to check and adjust it periodically.
Check the neck to determine if it’s straight
Look down the neck of your instrument to see if it’s bowed or curved in any way. Close one eye and peer down the neck from the headstock to get a general idea of its straightness.
If you notice that the neck is bowed outward or inward, then you’ll know where to start with adjusting the relief. It’s important to note that this is merely an exercise in sight, so don’t worry if you haven’t done this before and don’t know exactly what you’re looking for.
Attach capos to the 1st and 15th frets
Securely clamp two capos to the 1st and 15th frets of your guitar.
This creates a straight line that you can use to measure neck relief. It eliminates the issue of extra string height from both the nut and bridge, making it easier to accurately measure your neck’s relief.
If you don’t have two capos, fretting the low E string on both frets is an alternative solution. However, this will require another set of hands for help.
For shorter-scale guitars, where a capo can’t fit on the 15th fret, place it as close to the body as possible so you still have a straight line.
Take a measure of the gap between the string and the 7th fret
Using your feeler gauges, measure the gap between your guitar’s 6th string and the 7th fret to see if you need to adjust your neck relief.
If it fits snugly between the string and the top of the fret, then your relief is just fine. But if there’s resistance or no space at all when you insert the feeler gauge, then you’ll need to increase your relief.
On the other hand, if there’s still space between them after inserting it, then you should decrease your relief.
Make sure to use a 0.007 inches (0.18 mm) feeler gauge as a starting point for an optimal neck relief adjustment.
Correcting Neck Relief
Correcting neck relief is an important step in maintaining the playability of your guitar.
To do so, you’ll need to:
Remove the truss rod cover (if necessary)
Remove that pesky truss rod cover if it’s blocking your way.
On some acoustic guitars, this can be accessed through the soundhole, so look there if you don’t see a plate or notch in the headstock.
If there’s a cover, use a screwdriver to carefully remove it and set it aside.
Make sure you have easy access to the truss rod before continuing with any adjustments.
Fit the right hex key to turn your truss rod
Make sure the hex key fits right into the truss rod and doesn’t slip out. This is important because if you use a tool that doesn’t fit properly, you risk damaging your truss rod or even stripping it altogether.
Always be careful when turning any hex key as they can easily strip if over-tightened.
Turn the truss rod
Give the truss rod a slight twist, and don’t overdo it.
When adjusting your guitar truss rod, you need to be precise and accurate. Turning it too much can damage the instrument or cause other tuning issues.
It’s recommended to only turn the truss rod nut it 1/8 of a turn at a time. Whether you’ll turn the truss rod nut clockwise or counterclockwise, depending on whether you want to decrease or increase relief.
To make sure you haven’t exceeded this amount, think of 1/8 as half of a quarter turn.
In this way, you’ll be able to adjust the truss rod with confidence and accuracy for optimal performance from your guitar.
Retune your guitar and check the neck relief
Checking your instrument’s relief after adjustments is essential to ensure it’s playing its best. So, take a few moments to retune and see how it feels.
Clamp your guitar strings down at the 1st and 15th fret (or whichever higher fret you used before) and use a feeler gauge to check for any changes in relief.
If you find that you’ve gone too far, adjust the truss rod back in the opposite direction until it feels right.
Neck relief can be a personal thing, so if it feels good when you play, then there may be no need for further adjustment, even if the measurements don’t match what you wanted.
Adjust the truss rod another 1/8 turn or less if necessary
If the desired relief still hasn’t been reached, give your instrument’s neck a slight tweak of no more than an eighth of a turn.
To do so, use the truss rod adjustment tool to carefully turn it clockwise or counterclockwise as needed. Don’t forget that even tiny adjustments can make a difference, so don’t force it!
It might take some time and patience to get it just right. Remember to retune your guitar after each adjustment and check for the desired amount of relief.
Check your relief again after 24 hours
After 24 hours, check the relief again and make any necessary adjustments.
It’s important to let the neck settle for a full day so that you can get a more accurate reading on the amount of relief. Avoid moving or changing temperatures during this period as it could affect the truss rod adjustment you’ve made.
How to do the tap test
To perform the tap test, start without a capo. Fret at the first fret and use your pinky finger near where the guitar joins the body. Lightly press the string until it touches the top of the fret, and feel how much space is between them.
The amount of space between these two parts can tell you if there’s too much or too little relief in your guitar neck. If there’s too little space, it means that there’s backbow; if there’s too much, then upbow or excessive relief is present.
Repeat this process on different frets. Check after 24 hours to see if any change occurred due to tension shifts from tuning or playing.
Tips about Adjusting the Truss Rod
Adjusting your truss rod can make a significant difference in the sound of your stringed instrument, so it’s worth taking the time to get it just right.
When adjusting the truss rod on your guitar, make sure you give it plenty of time to acclimate before attempting any adjustments. This is particularly important if you’ve recently traveled with the guitar and experienced changing temperatures and humidity levels.
Have all of your tools ready before beginning work, including luthier tools if necessary. Make small adjustments at a time and wait for 24 hours between each quarter turn of the truss rod.
If you don’t feel comfortable making changes yourself, take it to an experienced luthier who can do this job safely and effectively.
Your guitar’s truss rod is the key to keeping it in tune and playing smoothly. With a little bit of knowledge and an understanding of how your instrument works, you can adjust the truss rod yourself.
Do it once or twice, and adjusting the truss rod will become second nature.
How often should I adjust the truss rod?
How often to adjust the truss rod depending on the amount of use and the environment you play in.
If you play more often or live in an area with extreme temperatures and humidity levels, it’s recommended to adjust it every few months.
Are there different types of truss rods?
Yes, there are different types of truss rods. Most electric guitars have either a single-action or double-action truss rod. Single-action truss rods allow you to adjust the neck relief only, while dual-action truss rods can both decrease and increase the amount of bow in the neck.
Some higher end instruments use adjustable truss rods which allow for more control over the instrument’s action and playability.
What are the signs that the truss rod needs to be adjusted?
The signs that the truss rod is out of tune are subtle but unmistakable: you’ll feel a slight buzz in the strings when playing open chords, and the neck might feel crooked or warped when you fret notes.
If your guitar is exhibiting these symptoms, then chances are it’s time to adjust the truss rod!
Is it safe to adjust the truss rod myself?
It’s perfectly okay to adjust the truss rod yourself if you’re confident in your abilities and have done some research to ensure that you know what you’re doing.
Just make sure to take your time and follow all instructions carefully for best results.