Guitar maintenance is something that every guitarist should be familiar with. Being able to setup your own guitar is convenient, saves time, gives you a deeper connection to the instrument, and—most importantly—can help you save some cash.
However, many guitarists choose to just take their guitar to a professional instead, and I get it. You get worried you’ll mess something up, break your guitar somehow, and just make things worse. This is especially true when it comes to truss rod adjustments. There have long been rumors, stories, and myths about people permanently damaging their neck by incorrectly adjusting their truss rods. But adjusting your truss rod is actually a fairly simple, easy, and safe thing to do if you have the proper knowledge.
Today, we’re going to cover the basics of what truss rods are for, when and why you need to adjust them, and how to adjust them safely on your own. By the end of this article, you should have the confidence and knowledge to save some cash and make your truss rod adjustments on your own.
What Truss Rods Are For
Before explaining how to adjust your truss rod, it’s essential to understand what truss rods are and what they are for. A truss rod is a thin metal rod that runs through the entire guitar neck. It sits just under the fretboard and is accessible via a whole behind the nut or near the neck joint.
So it’s a metal rod that runs through the neck, but what’s it for? Simply put, the purpose of the truss rod is to keep your neck straight. It may not seem like it, but a guitar with standard strings in standard tuning puts a lot of pressure on the neck. Without a truss rod, the neck will bend over time from that pressure. This is easily seen on older guitars prior to the advent of the truss rod, as many of them have had to have necks replaced due to the neck bending from pressure. But with a truss rod, you can accommodate for that tension and keep your neck straight.
It’s also important to mention that the truss rod’s purpose is not to adjust the action. This is a common misunderstanding, and it’s important to understand the truss is meant to keep your neck straight and not to adjust your action. Though adjusting the truss will have an impact on action, it likely won’t fix the action problems you’re having. If your action is too high or too low, there are likely multiple other factors involved such as nut height, bridge height, neck angle, etc.
When To Adjust Your Truss Rod
Now, let’s move onto when you should adjust your truss rod. As you may have pieced together already, your truss rod should be adjusted when your guitar’s neck is not straight. If your neck has a forward or backward bow, that means it’s time to adjust your truss rod and straighten out your neck.
There are a multitude of factors that could cause your neck to be bowed. Changes in temperature and humidity can cause a neck to bend. Changing to a very different new tuning like Robert Fripp’s new-standard tuning could even cause bowing if your guitar isn’t set up for it. It can even happen overtime naturally from the tension. Something as simple as changing to a different string gauge can have an impact too. Either way, if you notice bowing in your neck, that’s a sign you need to adjust your truss rod.
How to Tell If Your Neck Is Bowed
Though figuring out if you need a truss rod adjustment seems as easy as asking “is my neck bowed,” actually being able to tell if your neck is bowed can be harder than you think. So let’s take a moment to cover how you can see whether or not your neck is bowed and to what extent.
There are multiple ways to check if your neck is bowed, though some are a bit more mathematical than others. The simplest way is to just look straight down the neck from the nut. If the guitar has any serious bow, it will be pretty easy to recognize. However, this method isn’t very precise, and it can be hard to see if the bow is minor.
Another method involves using two capos, though you can get by without them if you have an extra set of hands. Place capos on the 1st and 15th frets. This removes the bridge and nut height from the equation and allows the strings to serve as a straight edge. The next step is to measure the gap (or lack thereof) around the 6th and 7th frets with a feeler gauge. If the gap is large, you have up-bow. If the gap is non-existent, you have back bow. You should be able to find suggested measurements for your guitar or similar ones on the manufacturer’s website.
How to Adjust Your Truss Rod
Finally, we are ready to adjust the truss rod. Actually adjusting the truss rod is probably the easiest part of adjusting your neck relief. The first step is to figure out where you can access your truss rod. It’s typically found behind the nut via a slot in the neck, but many guitars have it at the bottom of the neck as well. For some acoustics, it’s found inside the soundhole.
Then, you need to make sure that you have the right tool. Different guitars require different tools to adjust the truss rod, so figure out which one you need. Most guitars come with a truss rod tool, but let’s be honest—those often disappear just like picks seem to do. Take a look at your truss rod and see what tool you’ll need, or just check online to find the right tool for your guitar. Just be certain that you have the right tool, otherwise you may end up damaging the truss rod.
After all that, you’re ready to make adjustments. Just make sure you know what issue you are correcting. If your neck is bowed upwards, you’ll need to turn clockwise. If your neck is bowed backward, you’ll need to turn counterclockwise.
When making adjustments, go slow and small. Make minor adjustments and check them as you go. Small adjustments can have a big impact, so there’s no need to crank the truss rod by large amounts. Just carefully turn it a bit at a time and see how much it changes.
Adjusting your truss rod might seem scary, but it’s actually pretty simple. All you have to do is figure out if your neck is bowed (either by eye or by using feeler gauges), and make small adjustments to the truss rod accordingly. Being able to complete your own maintenance and make truss rod adjustments is a great way to save money and get a better understanding of your instrument. So next time your neck seems a bit off, try it yourself and save a couple bucks.