Being able to adjust your truss rod is incredibly important to maintaining your guitars playability. Without truss rod adjustment your guitar won’t sound as good. In this guide we’re looking at how to adjust the truss rod correctly and how it works for your guitar.
Understanding the Truss Rod
Before you being to try out truss rod adjustment you need to get an understanding of what it is and what function it has on your guitar. This is a very important part of the process and shouldn’t be skipped over if you haven’t explored what a truss rod does before.
Every truss rod is unique apart from their function. It’s there to adjust the guitar neck relief. Truss rods are made from steel but the composition of metals aren’t the same in every instrument. They will vary widely in terms of the steel composition, the manufacturing quality and the rod diameter.
The strength of a truss rod is what matters most. When you go to adjust the truss rod in either direction you will be changing the amount of force which is being applied to the rod. There are multiple forces that work on a truss rod which include tension, torque and compression.
When you loosen the truss rod by turning it anti-clockwose it adds relief to the neck of the guitar. This means you are decreasing the tension on it, resulting in an increased string action height.
When you tighten the truss rod by turning it clockwise you increase the compression. This helps to push the center of the neck away from the strings of the electric guitar. In turn it will lower the string action which means it lowers the height of the strings over the frets.
Overtightening a truss rod is a big no-no. As it becomes too tight you will apply more force than the rod can tolerate. The force then turns into torque that breaks the rod as well as the adjustment nut. A broken truss rod can usually be repaired but it’s very expensive to do so – normally going over what the electric guitar is even worth.
There are multiple types of truss rods for both acoustic and electric guitar. In this guide we’re looking at the two most common ones that are used most often in bass guitars and electric guitars. These are the single action truss rods and the dual action truss rods.
Single Action Truss Rod
Most commercially manufactured instruments will have a single action truss rod. These rods have been made to be tightened up so that the pressure on the back of the guitars neck is increased. The result of this force means that the guitar neck bows backwards. This may sound like a strange thing to want on your guitar but it actually helps to counteract any tension from the strings to help straighten the guitar neck.
Dual Action Truss Rod
The dual action truss rod allows you to adjust it in both directions so you can move it up and down. This type of truss rod creates relief for the guitars neck without adding in any extra string tension. A two way truss rod like this will also have a nut at each end so there are two adjustment points.
Turning the Truss Rod
Now let’s get into adjusting the truss rod properly. We’ll start out by finding out which was to turn it. The way the truss rod is turned will all depend on the effect that you want it to give. Before you tighten the truss rod it’s always best to give it a small turn in an anti-clockwise direction to slightly loosen it. A professional guitar setup for a bass or electric guitar means you want the neck to be completely level and flat. However, there is a curve to the neck thanks to the string tension which is why you want to be able to adjust the neck up or down.
You can decrease relief by tightening the truss rod which means you’ll have to turn it clockwise. This helps the neck to curve upwards and the string action will convex.
Relief is increased by loosening the truss rod. This is done by turning the rod counterclockwise. This will help to pull the neck up and away from the strings, meaning there’s a greater string height.
Checking the Neck Relief
As you adjust the truss rod in either direction you will constantly want to be checking how much relief is on the neck. Before you begin adjusting the truss rod you will want to carry out a neck relief check so you can estimate how much adjustment is actually required.
Remember that the total effect from any adjustments made to a truss rod will not be heard or seen immediately. The neck of the guitar, whether it has a back bow or a forward bow, will normally always have a delayed response to any changes. Make sure that you are minimizing any tension on the neck by not turning the truss rod more than a quarter of a turn in a 24 hour period. Once this amount of time has passed you can check the relief once again and then turn the truss rod if necessary to make further adjustments.
Checking relief on your guitar is very simple. Below we have given you an overview of how to check this on both electric and bass guitars.
Electric Guitar Relief
To check electric guitars relief you will want to take the top string and fret it at the first and last fret. You can capo the first string if you are having trouble. Find the seventh fret and then measure the space between the top of this fret and the bottom of the string. The measurement you’ve just taken is how much relief there is.
Bass Guitar Relief
Fret the top string once again and then fret it at the first and fifteenth fret. You can capo the first string here if you want to. Count to the seventh or eighth fret and then measure the distance from the bottom of the string up to the seventh fret. This is your relief measurement.
There isn’t a universal measurement that acts as a standard for all guitars. Normally you will want to be between .008″ and 0.15″. The amount there is will be completely up to you.
If you’ve done the steps above and still aren’t loving the string action then you may want to take a look and adjust the bridge and saddle heights. After making adjustments like these you will need to check and then adjust the intonation. Remember that the neck will respond to any adjustment slowly so the intonation of the instrument will probably need to be reset after some time has passed and it’s settled.
Truss Rods That Don’t Turn or Tighten
Truss rods can be complicated and you should always err on the side of caution if you’re planning on making an adjustment yourself. If you are concerned that you cannot turn or tighten the truss rod then you will have to consult a professional such as a guitar technician or a luthier.
Tools Needed for Truss Rod Adjustments
You will need a few tools to adjust your truss rod and truss rod nut properly. Not every tool on our list is needed so make sure you check what kind of truss rod you have.
- Small screwdriver if you have a truss rod cover that must be removed
- An adjustment wrench that will fit your truss rod nut
- A string height gauge with both 1/32″ and 1/64″ markings
- An electric tuner
Because truss rods are all different there isn’t one standard wrench that will suit every truss rod nut. You can get a box wrench, a hex wrench, a screwdriver or a nut driver. Using the wrong sized wrench can cause untold damage to your truss rod nut. You must always make sure you are using the right sized wrench with the right shape that matches the truss rod nut.
Adjusting Your Own Truss Rod
If you are planning on playing guitar at a professional level then it’s important to know how to do the basics of adjustments and maintenance on your instrument. There are lots of tutorial videos online as well as articles such as this that can help you learn these skills. But of course you will need the right amount of experience to become confident in the process.
Getting the right level of experience will come with some risk because there’s always the chance you could break your truss rod as you learn. You may also end up breaking the truss rod cover, messing up the string height or damaging the truss rod barrel nut. Getting your guitar professionally setup could cost you anywhere between $55 and $90. However, a broken truss rod can cost up to $300 to cost and in some cases it can’t be repaired at all.
Never be discouraged from learning the process because it’s all about practice. Even some of the best guitar players in the entire world once didn’t know how to adjust a truss rod. If you are mechanically minded and are good at tinkering with your guitar then making these adjusmtents by yourself could be easy to pick up.
Tips to Remember When Adjusting
- Don’t adjust the rod too much all at once. You only want to turn the rod a maximum of a quarter of a turn at a time and then leave it alone for 24 hours. Do this until you understand the ins and outs of your rod and how it reacts to being adjusted.
- Always remember to re-tune your guitar before you check how the adjustment has worked.
- Never force your truss rod to turn or tighten. If you are feeling a lot of resistance then your truss rod could be at its maximum. Making any further changes by tightening or loosening it could end up damaging the instrument. In this instance take your guitar to a professional for a full inspection and repairs.
- When loosening the truss rod if you don’t feel like any adjustments are happening then you may have a dual action and not a single action truss rod. You should go back and the check the guitars specs in this instance. If it is a dual action rod then eventually it will catch as you turn it and you’ll be able to make any adjustments you want.
- Whether the guitar neck is a back bow or a forward bow it won’t adjust immediately. Always make your changes and then let the neck settle overnight. This helps to make sure it doesn’t over adjust itself.
So there you have it. A guide on what your truss rod is and how you can adjust it yourself. Remember to be careful and take your time with any adjustments made.