How To Adjust Truss Rod Acoustic Guitar?

Adjusting your acoustic guitar’s truss rod can be a hard thing to do if you’re new to the world of acoustics.

how to adjust truss rod acoustic guitar

To be fair, and to adjust my previous statement, it can be a hard thing to do even if you’re not new to the world of acoustic guitars. 

In a short and quick summary, you can fix your stripped acoustic guitar truss by removing several parts, including the headstock veneer and the neck, which we will discuss in detail. 

Then, examine the condition of these parts. Most often, when you need to fix a stripped truss rod, it’s because the neck of the guitar is broken. If that’s the case, you will have to replace it.

This guide is going to cover the various steps that you need to take to successfully adjust the acoustic guitar’s truss rod and how to adjust truss rod acoustic guitar.

Of course, with all things like that, it’s easier and quicker to show you on an actual acoustic guitar. 

But, we can’t do that, so we will provide you with the next best thing. This guide will cover how you need to turn your truss rod to tighten it to loosen it and what happens when you do it.  

Okay, What Is A Truss Rod?

A truss rod is a minor but significant piece of kit inside any guitar. 

If you were looking at it, all you would see is a thinnish, longish, sturdy metal bar. But you can’t look at it when it’s in a guitar, because it is concealed by the guitar neck, fretboard, and strings.

So you’ll either have to take your guitar apart or take our word for it. 

The truss rod sits the entire length of the neck, so that should give you a better idea of how long it actually is.  

What Do I Need To Adjust The Truss Rod?

You need to know:

1. Where the truss rod is, so you don’t mess around in the wrong place. 

2. What you’re doing, so you don’t do the wrong thing and break your guitar. 

3. And, a truss rod adjuster nut. This is a little tool that will come in handy when you’re doing the actual physical adjusting of the truss rod.

It will be extremely difficult to do without.  But, you could replace it with any little adjuster nut or a similar or correlating size.

It would have to be the same specific size in order to avoid damage to both the truss rod and the integrity of the acoustic guitar.  

So, Where Is The Truss Rod?

We’ve discussed how the truss rod runs up the neck of the guitar.

What you also need to know is how to access it. Most truss rods can be accessed through their end point. This is normally in the sound hole, right at the top, just where the neck ends. 

It is a small opening and quite a fiddly part, but it’s not inaccessible at all. You can do it with a bit of forward planning.  

Truss Rod Adjuster Nut

The truss rod adjuster nut is a little part that will be your best friend throughout this process. 

If you want to dive deeper into truss rod adjuster nuts, there are a few good guides that you can read. 

Truss Rod Bolt And Directions To Turn It: Loose Vs Tight

The direction that you’re turning the truss rod in depends on whether you are loosening the truss rod or whether you are tightening the truss rod.

Loosening the truss rod does have a drastically different effect to tightening the truss rod. You need to know which way you want to go and what you’re trying to achieve before you start the process. 

Let’s start with tightening the truss rod.   

Tightening The Truss Rod

How To Tighten The Truss Rod

Have you ever heard ‘righty-tighty’? It’s a common phrase that people use around the world to help them remember which direction to tighten things up in. 

Well, it’s the same for your truss rod. If you want to tighten it, you have to navigate your hand and your nut in the direction to the right. 

You can also think of this as a clockwise direction. We are going to use a visual aid to help you get the picture here. 

How Do I Adjust My Truss Rod On My Acoustic Guitar?

In this image, you can see the truss rod. You can also see the fretboard and neck and sound hole of the guitar. 

This position is the one that you’re going to get yourself into when doing any adjustment work on your truss rod.

It is the easiest and most simple, straightforward, and accessible way to start to alter the truss rod tightness. 

You can also adjust the truss rod while the guitar sits in your lap as though you were playing it sitting down.

If you choose to do it this way then to tighten the rod, you are going to push away from your body as opposed to towards your face.

But, as we said, we recommend the other method over this one any day.  

Why Would You Need To Tighten The Truss Rod?

Okay, we have established the where now we are going to think about the why. What are the reasons that have led you to want to tighten your truss rod in the first place?

Our acoustic guitars can relax and change form in a number of conditions. They are made from natural materials alongside synthetic ones and because of this fact, they breathe.

The wood can relax, the strings can shift and end up sitting too high on your fretboard.

Sometimes, your sound will suffer as a direct result of this process. 

This can be things like humidity, heat, and even less often, the freezing temperatures. But, it’s normally the heat and moisture that have this effect on your instrument.

If the strings are not sitting high enough up on your fretboard, your whole sound will sound off. 

But it can also be as simple as it’s a new acoustic guitar fresh out of the factory. Sometimes, new guitars are made with strings that sit high with a truss road that is tightened up.

If this is the case, you can play around with the truss round to try to find the sound you love from your acoustic regardless. 

If you are wanting to tighten up your sound,  a good place to start would be by making small adjustments to your truss rod.  

When tightening the truss rod – go extremely slowly! Its a delicate job and not one to be rushed. Usually an 1/8 of a turn is enough – you would be surprised how little it takes to make a difference to the action (height of the strings off the fretboard). 

What Are The Effects Of Tightening The Truss Rod?

Tightening the truss rod essentially tightens the guitar neck. It pulls it in a backward direction and puts pressure on through this process.

When you do this, the strings and how they sit and pull against the tuning pegs and the fretboard will be curbed.

You can think of it as though you are restraining the strings and putting a bit more pressure on them. 

One negative consequence of adjusting the truss rod is that you can alter your acoustic sound in a way you don’t want. 

What we mean by this is that you can cause yourself problems if you get the adjustment wrong.

It is entirely possible to make the truss rod too tight, and therefore bend the neck too far in the wrong direction. 

If this were to happen, you would be left with a fuzzy sound or even, no sound whatsoever from your strings. Obviously, you want to avoid this at all costs. That’s why you’re reading our guide.  

Loosening The Truss Rod

How To Loosen the Truss Rod

We have now seen how to tighten the truss rod, so let’s talk about how to loosen it. Forget righty-tighty for the moment. Now we are going to focus on its counterpart – ‘lefty-loosey’. 

You got it. If you want to loosen your truss rod, you have to go in a leftward motion, from the position that we have previously discussed. If you need a reminder, here is that image again. 

How Do I Adjust My Truss Rod On My Acoustic Guitar?

So again, we can see the sound hole and the access point to the truss rod. We’re going to reiterate that this really is an easier way to access the truss rod and make any modifications that you need to make. 

If you are going to do it from the sitting lap position, then the key point to keep in your mind is that you are going to be turning the adjustment nut towards your face, not toward your body. This is the same as a left turn. 

Top Tip

When making any adjustments to your truss rod, do it slowly. Slow and small movements win the day here.

You don’t want to do anything too drastic, make too big of an adjustment, and have to peddle back rapidly.

You can cause real damage to the integrity of your acoustic guitar if you dive in heavy-handed and adjust too hard. We are talking an eighth of an inch turns here, people.  

Why Would You Need To Loosen The Truss Rod?

You might need to loosen your truss rod if your strings are looking a bit low down. 

If your strings are too low down, just like if they are too high, your whole sound will be messy.

This can cause muting, it can cause weird buzzes, you might even notice the tuners slipping more often than you’d like. 

Loosening your truss road relieves the pressure on the neck of the guitar and adjusts the strings’ position alongside it. 

What Are The Effects Of Loosening The Truss Rod?

If you loosen the truss rod, then the neck will bend in the opposite direction to when it is being tightened. It can even bend forward.

If your guitar has been set in a damp room, then you may notice that your strings have shifted. This is not uncommon because instruments are made from materials that work in this way. 

Ultimately, you will end up with a cleaner sound overall.  

Letting Your Neck Adjust 

Once you have played around with the truss nut and have finished making your adjustments, there is another vital part to the process that you need to observe.

This is the fact that you have to allow the guitar neck to settle down. You can play as you adjust to hear what the adjustment does to your sound.

However, in a few days, things will have shifted again, even if it is only slightly. 

We recommend that you sit on your adjustments for around 24 to 48 hours.

After this, your instrument will have made its own natural adjustments, and you will be able to tell what the overall consequences of your meddling have rendered.  


Will adjusting the truss rod on my acoustic guitar lower the action?

The truth is that tinkering with the truss rods of your acoustic guitar will have an effect. While it will definitely lower the action, the depth of it all will depend on two things. 

First, it depends on the distance you will create between the nut and the saddle after the adjustment. 

Second, the lowered action will also be determined by the tension on the strings at the end. This tension will be based on how tight you will make the strings.

How do I know if I have to tighten the truss rod on my acoustic guitar

There are two top signs to watch out for if you are not sure whether you’ve to tighten the truss rod on your acoustic guitar. 

The number one sign to be on the lookout for is whether there is any change in the action. Second, what’s the height of the strings over the frets? 

If the height is too low or high than usual, then it’s time to make some adjustments.

Conclusion – How To Adjust Truss Rod Acoustic Guitar

Adjusting your truss rod can improve your sound. We hope with our guide you have a better idea of how to adjust the truss rod in either direction now. 

With that in mind, if your guitar is still failing you, it is probably time to give it a full MOT and run down.

This includes things like looking at your saddle bridge, checking your string deterioration, and looking over the tuning nuts in more detail too. 

The biggest thing to remember if you decide to give truss rod adjustment a go, is that right equals tight and left equals loose.

Have a very clear goal in mind for what you want to achieve through your truss rod adjustment, and adjust it according to that vision. I hope you got your answer about how to adjust truss rod acoustic guitar.