Truss Rod Tips

Checking the neck relief, adjusting the rod and much more...

Ultimate Guitar
Truss Rod Tips

1. To check your neck relief, place a capo on the first fret of any string (the lowest string is the easiest to measure with) and with your picking hand, fret that same string on the fret where the neck joins to the body. Then inspect the gap between the fretted string to the 7th fret. A setup that's suitable for the way most people play is about 0.5mm (≈ 0,02 in). You can measure this accurately by sliding a feeler gauge the appropriate thickness between the string and the fret. Too little gap or no gap whatsoever means that the truss rod is too tight. More than 0.5mm indicates that the truss rod may need to be tightened,

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2. This method is also a way to tell if your neck is twisted or your frets have excessive wear on one side or the other. Measure the relief with the method listed above on the bass side and also measure the same way on the treble side. A perfectly straight neck calls for both measurements to be exactly the same. Any deviations indicate that the neck could be twisted.

Make a note to say however, that sometimes just looking down a guitar neck to check for twist can be a bit deceptive, because the nut action on most guitars does tend to be lower on the higher strings, and that can sometimes create the optical illusion of a twist. Measuring the relief of the bass string and comparing that gap to the amount on the treble string with a feeler gauge is more accurate.

3. To adjust the truss rod, ensure that whatever adjustment tool you use (be it an Allan wrench, a screwdriver or a box spanner) is fully engaged with the nut it indexes into. Avoid adjusting the truss rod without the tool fully engaged or you risk chewing the adjustment nut up.

4. Asian-made guitars generally call for metric tools to adjust them. US-made guitars (and some Mexican) generally call for Imperial. This is very important because a 3/16" Allen wrench is ever so slightly undersized for the 5mm barrel nut to adjust the truss rod found on many Asian-made guitars and you seriously risk stripping the barrel nut out if you use a 3/16" wrench on a 5mm truss rod. Make sure you use metric tools on metric parts!

5. Truss rods nearly always tighten in a clockwise direction facing down the adjustment nut. This means that a truss rod nut at the bottom of a guitar's neck will adjust in the opposite direction to one at the top of the neck.

6. Only tighten the truss rod up to a 1/4 turn at any one time. You can tighten it more than that, but allow time for the guitar' neck to stabilize from the forces you're imparting on it before you adjust it further. Measure your neck relief again with every adjustment you make.

7. Some truss rods can act on the neck in both directions. They're called 2-way truss rods and they're more common on modern guitars. If you guitar has one, you can turn the truss rod counterclockwise and it'll actually force the neck into relief rather than straighten it out. This can be very useful when you want to use really light gauge strings or if you neck naturally backbows with no string or truss rod tension on it.

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8. If you have adjusted the truss rod to be very tight, and you're still not getting the correct neck relief, consult a guitar tech. Overtightening the truss rod can cause damage that is very difficult and expensive to repair. Exercise common sense; If you feel as though you might break the truss rod if you tighten it any further, STOP.

9. If you're about to adjust the truss rod and it's already tight, always start adjusting it by loosening first.

10. If your guitar's action mysteriously seems to raise or lower when you can swear on your mother's life that you never adjusted the action at the bridge, then do not adjust the action at the bridge. Check the neck relief in the method mentioned at step 1 first. Chances are, you'll find that the neck relief has changed, which has lead to the loss in playability. Adjust the truss rod accordingly. Adjusting the action at the bridge when only the truss rod needed to be adjusted will only compound the problem your originally had; because not only is the neck relief still not set correctly, but you've now set the string height at the bridge incorrectly too. 


29 comments sorted by best / new / date

    Always enjoy the guitar related articles. Great post.
    How'd you earn that money? Suck dicks for nickles? I hate how many bots are on here now.
    Good article, from a good user. Struggled with Truss rods over the years and this article has provided a shedload of help. Cheers!
    I like to adjust my truss rod with a drill. I just let that baby rip and when I hear a crack I stop tightening pretty soon after that. I do have a bit of fret buzz but it dies down significantly by the 20th fret.
    Most useful article on truss rods Ive read here. I have 2 guitars with wonky action that I now have the confidence to try to repair. Thanks!
    I only use the 3 notes per string method to make truss rod adjustments. The CAGED method of neck adjustment is ineffective and a waste of time.
    This article gives people just enough info and experience to be really dangerous, coming from a luthier/tech. There are many variables and measurements not taken into account in this article. Its not as simple as looking down the neck for straightness. That's just the basic idea.
    Did you actually READ the article before commenting? Because sighting down a neck to determine its relief is not what it says. What it actually says is that measuring with feeler gauges is more accurate and that sighting down a neck to determine is relief can be deceptive.
    Like I said there are many factors not being considered here. I understand a feeler gauge was mention. String action, intonation, and a correctly playing/sounding instrument are all set properly by a combination of factors and variables including but not limited to truss rod adjustments. It's only the starting point and usually requires all other adjustments, once the truss rod tension is changed. Take it for what you will but this article will only give you false confidence you are making your guitar play better unless you know what other things your looking for in a proper setup.
    If this article covered the topics of string action and intonation, then the article wouldn't be called 'Truss Rod Tips' would it? It would be called 'How to set up a guitar.' Nowhere in this article does it imply that a truss rod adjustment is all you will need in a guitar's setup to make it play properly either. So I really have no idea where the criticisms you're making are coming from. If you claim to be such an 'expert' on the topic, then go off and make your own article.
    You should only adjust a truss rod if you are prepared to adjust everything else to compensate for the changes in the neck length and straightness. In summary, you shouldn't be adjusting your truss rod if you don't know the rest of what goes into that adjustment and a proper setup.
    What this article teaches is how to adjust the truss rod in a way that cannot do any damage. Adjusting the truss rod and neglecting to adjust the string height and the intonation is not going to do anything damaging or that cannot easily be undone. There are situations that call for a truss rod adjustment without adjusting the string height and the intonation at all anyway. Such as seasonal changes causing changes in temperature and humidity. Temperature and humidity are not going to make any difference to how to the bridge height and the intonation is set, at least not on an electric guitar. But it can affect the neck relief. So the only thing that needs to be done to restore the guitar's playability is adjusting the truss rod and nothing else. You should already know that anyway, coming from a self proclaimed 'luthier.' But even the so-called 'luthiers' need their 'profession' to be taught to them, it seems.
    Every instrument is different case by case. They all need different amounts of adjustment to one or more areas 95 percent of the time. Sometimes a truss rod adjustment; sometimes not. Unless you know what your looking for across the whole instrument and all settings, then you couldn't accurately assess if it only needed a truss rod adjustment. It takes a full knowledge to asses that call; not reading an article online that says, this is all you need. Also, what's to say the bridge action and intonation of the saddles is even accurate to begin with when before the neck is adjusted. If the person changes string gauges or tuning in the instruments lifetime then a truss rod adjustment won't address all the changes that need to happen if you do one or both of those things. Something an inexperienced reader wouldn't know.
    Gee, maybe you should write up your own article on the subject, if only such an article didn't make your 'profession' redundant. What you're addressing are scenarios that are outside the scope of the article. There wouldn't be an article large enough to cover the scope of all the possible scenarios that may lead to a guitar's poor playability. And if there was, it would be so drawn out and long that hardly anyone would be bothered to read it. An instructional article that nobody will bother reading is a complete waste of time. As a general guide of solely adjusting the truss rod and the basics of how to measure relief however, this article suffices. But of course, I know you'll say that it doesn't suffice. But I can argue all day that the only reason you're saying that is because you have an agenda of protecting your job. But do keep wasting your time.
    Ouch, ya I can feel business slowing down already. It's a public forum, if you don't like how others critique it or praise it, then keep it private. Have a good one.
    I suppose I could look at these articles as job security because someone will need to fix the instruments after someone who doesn't know what they are doing, starts adjusting settings. I don't make detailed articles/comments on this subject for the same reason, job security.
    ...And then charge those people up the ass for something they can easily do themselves just as competently for free. If your customers only knew what an attitude you had, I don't think they'll be sending their $2000 guitars to fix up anymore. Certainly not me, I'd send it to someone who wasn't such an asshole.
    My point was not to stir up drama. I still stand by my point that if you don't know how to fully adjust the whole instrument, then you have no business adjusting the truss rod. Also it's not like I am plugging my own shop or telling people to come see me personally. I don't do that on UG.
    Adjusting the truss rod is the most sensitive aspect of adjusting a guitar's setup. Adjusting the string height and intonation cannot do anything destructive or that cannot be easily undone. This article covers truss rod adjustment specifically. If you want to learn about how to adjust the string height and the intonation in the interest of learning how to do a job you should already know how to do, then go to another article. Simple as that.
    ...and now we know why
    Get off the guy's back, he's making a very valid point. Any change you make to the truss rod is going to have an impact on the intonation, even if minor. You're adjusting the mid point of the strings on the guitar, and therefore the intonation will waiver slightly. It's a good article if you know the truss rod is the issue, but damn right you're gonna affect other things, just like string gauge has an impact, as does a tremolo to the tuning.
    How about an acoustic guitar, aren't they set differently
    The principle is exactly the same, as are the measurements you need to take. Truss rods on acoustics may need to be adjusted more frequently than electrics due to acoustics being more susceptible to temperature and humidity changes. But of course, if you measure the relief and it is still correct, then it makes no sense to adjust it.
    This is pretty much the standard way to set up a neck. I can hardly believe the way I see frets hacked away on used guitars when a bridge, pickup, or truss rod adjustment would have fixed the problem. Ibanez guitars are factory set with a straight neck but most are meant to have a slight bow. I apprenticed with a luthier and was taught to set up with a straight neck on our new guitars and after fret jobs. A simple set up would be done with a slight neck bow.
    Great article, from a knowledgeable user. You can have confidence if you apply what you've read here you'll get desired results and have a much better playing instrument.