Last month a guy called me, telling me the truss rod on his brand new guitar was broken and asked if he could return it. I’ve had experiences with people saying there is something wrong with the truss rod, when in fact it is perfectly fine, so I was a bit skeptical. Sure enough, I received it in perfect health. There is a reason for some people’s thought that there is an issue, but let me start at the beginning.
What is a truss rod and why is it there and why is it placed on the guitar somewhere? The truss rod is a bar, usually made of steel, inside the neck of fretted instruments. The purpose for this is to prevent warping or twisting and to stabilize the neck. Wood is susceptible to changing and bending, depending on factors like environment, climate or humidity. The necks on fretted instruments are also highly affected by the tension of the strings (how many strings, or whether they are nylon or steel strings, etc). Adding the truss rod helps the neck stay straight by reversing the effects of the tension from the strings and natural susceptibilities of the wood.
When you adjust the truss rod, you are either straightening or slightly bending the neck. Tightening the truss rod straightens the neck… and loosening it bends the neck in response to the tightness of the strings. The tension of the truss rod, combined with the height of the bridge, decides how low or high the action is. Generally people want low action, but not so low that the strings are touching any of the frets as this causes issues of its own. The height of the action determines the playability and intonation from your instrument.
The first time someone came to me saying their truss rod was having issues, they actually thought it was snapped. Yikes! So I took it to our luthier and asked him to look at it. He told me there was nothing wrong with it… So how could this person not only think the truss rod was defective, but snapped?
Our luthier explained to me that the truss rod used to start at about the second or third fret inside the neck, and then go all the way to about 1-2 inches from the end of the neck, past where the neck meets the body. But in recent years, Teton (and I think other guitar manufacturers) have started the truss rod all the way at the nut, and that it doesn’t go as far past the body, inside the neck. This makes it so the truss rod is no longer 1-2 inches from the end of the neck, but 3-4 ½ inches so you need an entirely different length allen wrench. So when these people get their guitar and go to adjust the truss rod, their allen wrench wouldn’t even touch it, giving the impression that something was wrong.
We’ve since updated the size of the wrench we send with our guitars to prevent this confusion. I would like to say that even though you’re now more educated on what a truss rod is, and its purpose, I suggest never touching it. I’d advise that if you’re having issues with your guitar, take it to an expert. Messing with the truss rod can cause problems with your guitar such as; buzzing, intonation issues, the angle of the neck… and yes, the truss rod can even snap. I personally love to understand more about my instruments and how they work, but I will keep letting professionals adjust and fix mine, so nothing terrible happens to one of my babies.
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