Loose truss rod nut?

[VinceAAK]

Hello all,

Forgot my old account info and it's been years so I created a new one. First things first, already placed an email and phone message with EB customer service and waiting on a response. Just trying to see if I can get ahead of this.

I went to make a truss rod adjustment (2020 SR Special SLO Special HH) last evening and gave it a quarter-turn in the counter clockwise direction. When doing so, I did not encounter the typical resistance I feel when making an adjustment. The wheel just seemed loose...as in, I was able to make the wheel turn counter-clockwise by rolling my thumb over it. After seeing this and realizing something was off, I went to turn the truss rod clockwise to restore it to its previous position, yet there was the typical resistance when tightening the wheel. I don't think I adjust the neck more than a couple of quarter-turns a year when needed, so I have a hard time believing I maxxed out the relief (it doesn't seem like it's stripped, either), but I'm no luthier.

I'm comfortable taking the neck off and looking at this myself if it's a simple fix. But, I'm also worried about causing harm to the neck tension if the issue is likely to require more than "tightening a few screws". Has anyone encountered this?

 

[tbonesullivan]

What gauge strings do you use on the bass, and what kind of relief do you usually set for? It could just be that it is right at point where it stops putting pressure on the neck. As it is winter and moisture is less now, that puts necks into a forward bow naturally, so usually you loosen the truss rod. Maybe it's more dry than usual?

 

[VinceAAK]

Thanks for the reply. Actually, as I've been researching this all afternoon, I think I might be arriving at the culprit. I need to share a little more information:

I actually meant to tighten the truss a little and in a brain fart moment, loosened it a quarter turn and that's where I noticed that I may have just inadvertently been a quarter-turn or so away from completely loosening the truss as far as it'll go. That's my working assumption before I take the neck off for further inspection (plan on looking later tonight when off work).

Compounding this is that I needed to have the input jack replaced a few years ago, and when I took it to a luthier for the fix, I also got a fresh setup. Since then, I did have to take the neck off once, and noticed that he did add in a shim at the neck joint when he was setting it up. I actually don't know that it was necessary at the time, but figured I didn't notice anything then, so no harm, no foul....as it turns out it's possible that the shim might be an issue in and of itself (but I need to investigate further, and I digress)...

To answer your question, I typically use the EB custom gauge (45-105...the orange packaging ones) and usually make adjustments by referencing the factory specs as my guide. I have a hard time believing I've loosened the truss so much that I've loosened it completely, but I don't know how much of an adjustment was made the last time it was professionally looked at (~2.5 years ago). I'm wondering it was just at the end of its relief and I was correct in that it just needs tightening a little.

Edit: I do live in Alaska as well. Definitely fluctuations in temp/humidity but I keep mine stored pretty consistently around 68F degrees. I definitely make more truss adjustments compared to when I lived in the lower 48, but it's never been problematic before.

 

[Golem]

Most MM basses are built with a shim. I doubt it was added by your luthier.

If the shim looked hand made then your luthier made a new one to re-adjust your string height.

Do not remove the neck when having an issue with the truss tension. Theres no "there" there. You dont pull out an engine just to adjust the fuel injection. Just like you cant adjust the fuel on a disconnected engine, you cant set the truss rod tension on an unstrung neck.

 

[VinceAAK]

Absolutely, and thank you for the feedback. I haven't taken anything apart. Since my initial posts, I did get a response from MM customer service, who responded that i likely am just at the end of the relief, and the tension I felt when tightening the wheel, was the wheel rethreading itself. This makes sense, the neck looks good, the bass plays well. I can make some string height adjustments and go from there. I wouldn't imagine I'll need more relief, but down the road in the future, I just hope I'm not at point where I do need it and then run into this issue again.

There's definitely a first time for everything. Have been playing since 08, and MM almost exclusively since 2010, and I had just never run into this issue before!

 

[Razzle]

So what does one do if the neck is at the 'end' of it's relief naturally and when adjusting the truss rod more to get relief you cannot, it's only turns loose.

What's the fix for that? Is there a fix?

 

[nebadon]

What's the fix for that? Is there a fix?

New Neck

 

[Mu5icM@n]

I’m not sure I understand. Loosening the truss rod nut will put more forward now into the neck, giving you more relief. So if I’m understanding you correctly, you’re saying the neck was too flat and you needed to loosen the truss rod wheel and it just spun freely? Or do you need a higher action? Relief and string height are related but two very different things. A shim will not affect relief at all, it will give you more room to achieve a lower action (potentially) by angling the neck such that a given saddle height will place the strings at a lower height off the frets.

I’d actually take the neck off and see what’s going on with the truss rod wheel. Has it spun off the threads? If so you’ll find that out quickly by pulling the neck.

Also knowing what type/gauge strings you’re using would be helpful.

There are other options besides a new neck, also, depending on what’s wrong with it. A plek job might be able to put the right amount of relief into the frets, or there are places that will try to use heat and other techniques to put some bow into the neck.

 

[Golem]

New Neck

Not usually. Many luthiers know how to steam a neck into a very slightly new shape such that youre no longer at the limit of tension adjustment. A slight increase in the bow shape of the fully relaxed neck is what they achieve with steaming while the neck is clamped in a jig.

Ive even managed this fix myself with gentle heat and no steam. Took about a week. Home made jig involving scrap lumber and bungee cords.