Recently I removed the neck on a client’s vintage Tele to adjust the truss rod. The nut looked like Photo 3, which illustrates what happens when someone uses a screwdriver that’s the wrong size. The slots get deformed, and this makes truss rod adjustments difficult. The good news is these nuts are easy to remove, even when they’re butchered like this, but unfortunately it’s nearly impossible to find a “period correct” replacement. Sure, there are plenty of aftermarket parts available, but for a vintage guitar, it’s imperative to use period-correct parts to maintain its value. I mention this simply to drive home the importance of using the correct truss rod tool—one that fits snugly.
Worn-out tools will also damage a truss rod nut. For example, if the truss rod requires a hex key and its edges have become worn and rounded, it can in turn round out the inside of the nut. It’s important to check your tools to ensure they won’t damage your guitar.
A basic guitar tech principle: Replacing worn tools is much cheaper than fixing the damage they can cause.
Tools for removing a stripped nut. There are times when you can use the specified tool to remove the nut, but often you have to be creative. Once when working on a Gibson electric, I had to remove a hex nut that was so stripped that a nut driver wouldn’t grip it. Fortunately, a pair of needle-nose pliers did the job, but you must be careful to avoid stripping the nut more than it already is as you remove it. An improvised tool can easily damage the headstock, so proceed with caution.
Important: Always slacken the strings before you remove the truss rod nut.
In other cases, I’ve used a small flathead screwdriver to extract a nut when a hex key wouldn’t work. For example, by gently tapping the screwdriver into this stripped bullet nut (Photo 4), I was able to get it to catch hold. I turned the screwdriver counter-clockwise and voilà, the nut came off.
I’ve also used a screw extractor, a tool that looks like a drill bit, but with a twist: Screw extractors have tapered, reversed cutting threads designed to dig into a damaged screw and grip it tighter as you turn the extractor counter-clockwise while carefully applying pressure. The counter-clockwise movement backs out the damaged screw—typically its head is mangled or broken off—even as the extractor bores deeper into the screw shaft. I do this manually using a T-handle, but you can also use vice-grips with a screw extractor. I’d advise against using a power drill for extraction, but some techs do, running the drill at slow speeds. Using an extractor to remove a stripped truss rod nut takes a lot of patience, but it’s doable. The trick is to be gentle but firm.
Installing the new truss rod nut. This is the easy part. Just slide the nut onto the truss rod threads and turn it clockwise. Tighten the nut until it’s just a little snug. Tune the guitar up to pitch and check the relief in the neck. Depending on your playing style, .010" to .012" should be plenty of relief. Check out “Time for a Neck Adjustment?” if you’re not sure how to adjust the truss rod.
Averting disaster. A stripped truss rod nut is bad news, but it can usually be replaced inexpensively. However, if you strip the threads or nut at the other end of the truss rod—where it screws into hardware embedded within the neck itself—that’s a different story. Also, if the exposed threads on a truss rod are stripped, a replacement nut will not help. In either case, the truss rod itself would need to be replaced—a very invasive and expensive repair. At that point you have to decide whether replacing the neck makes more sense than spending a fortune on major surgery. The bottom line is simple: When adjusting your truss rod, don’t over-tighten the nut.If you’re not comfortable working with your truss rod nut, consult a qualified repair technician. Guitar techs and luthiers deal with these issues all the time, and paying them for their expertise can be a wise investment.