truss rod loosening?

tranceFusion · #1 01-30-2009, 08:37 AM

It seems like once a month or so, I have a realization that my action has gotten quite high on my bass. When I check the neck, there is a ton of relief. The bass was manufactured less than a year ago.

I am wondering - is the truss rod slipping/loosening, or is this just a function of newer wood settling in? Is this going to cause me long term problems?

JLS · #2 01-30-2009, 09:14 AM

Have you had this bass setup? If not, I suggest you do so.

Slowgypsy · #3 01-30-2009, 09:18 AM

Do a search on truss rods, or take a look at the Stickys at the beginning of this forum.

No... there's nothing "wrong" with your instrument. The neck on your instrument is made from wood. Wood naturally swells and shrinks with the seasons... different temperatures and humidity.

Truss rods are meant to be adjusted, to "counter act" the natural movements of wood. The truss rod in the neck of your instrument sounds like it could use and adjustment. Check the relief on your neck either using the straightedge thickness gauge method (science) or by sighting down the neck to see how bowed it it (art).

Again... check out the stickys at the beginning of this forum... lots of step by step info to help you through the process.

rumblethump · #4 01-30-2009, 09:19 AM

The relief on my Carvin needs to be adjusted 4 times a year due to change of the seasons, different humidities, and temperatures cause it to move . Have you adjusted your truss rod at all this last year?

tranceFusion · #5 01-30-2009, 10:40 AM

Apparently it wasn't clear from my first post. I AM adjusting the truss rod myself approximately once per month. Given my other basses do not require a truss rod adjustment this frequently, and the fact that it is always a tightening that is required seem bizarre.

I can understand that the wood swells and shrinks. The problem is that I am ALWAYS tightening the truss rod, never loosening it. If I had to move it one way when it got hot and the other when it got cool, then I would not be asking this question.

I have searched using the google search using several different terms and could not find an answer to this specific issue.

My understanding is that a truss rod can't be tightened infinitely so the fact that I am ALWAYS tightening it without running into a stopping point makes me thing that it is loosening itself.

Slowgypsy · #6 01-30-2009, 10:51 AM

OK... got it... your first post wasn't exactly clear.

Is this a new bass? What I mean is... if you just got this bass a few months ago, and you've found yourself giving a little tweak every month, I'd say the neck might just be settling in.

If this is a bass you've had for a while... how much do you turn the truss rod nut each adjustment? 1/8 turn? 1/4 turn? 1/2 turn?

Have you recently changed strings, say from a light gauge to a heavier high tension gauge?

Has this instrument ever been professionally set up? Or do you do your own setups?

I know, some of these questions are fairly basic... but without actually being able to see the instrument it's hard to give a diagnosis. If you've done your own adjustments, on several instruments, for several years, then you've got a fairly good idea of what's normal or not.

If you could give answers to some of the above questions... I'll check back here later on. But... yes... it is possible there is an issue with either the truss rod or the truss rod nut.

62bass · #7 01-30-2009, 11:07 AM

Quote:

Originally Posted by tranceFusion

Apparently it wasn't clear from my first post. I AM adjusting the truss rod myself approximately once per month. Given my other basses do not require a truss rod adjustment this frequently, and the fact that it is always a tightening that is required seem bizarre.

I can understand that the wood swells and shrinks. The problem is that I am ALWAYS tightening the truss rod, never loosening it. If I had to move it one way when it got hot and the other when it got cool, then I would not be asking this question.

I have searched using the google search using several different terms and could not find an answer to this specific issue.

My understanding is that a truss rod can't be tightened infinitely so the fact that I am ALWAYS tightening it without running into a stopping point makes me thing that it is loosening itself.

really doubt that the nut is loosening by unwinding itself on the threads. I've had that happen on the bridge saddle height adjustment screws on a P bass but never on a truss rod nut. The fact is you have to keep tightening but never loosening it and that makes me think that either the wood under the nut is soft or drilled roughly and keeps compressing. Or the problem might be at the other end of the rod which would make it really bad news. However, if you keep tightening you will soon run out of room to turn the nut anymore.

I'd go back to the tried and true washers under the nut trick. I'd remove the neck and take off the nut. Slip 2 or 3 washers (depending on their thickness) of appropriate diameter over the rod, put the nut back on and tighten it up until it just meets resistance. Then, clamp the neck into a slight back bow and snug up the nut until it just meets resistance again. Take off the clamp and re-instal the neck and strings and tune up. Then check your neck for the right amount of backbow and adjust the truss rod until you have it. If it continues to need adjustment a lot after that, then you really have a big problem that requires an expensive fix.

Sorry I don't have the ability to sketch out how to clamp the neck if you're unsure of how to do it. Perhaps someone else here can do it or post a link. It's actually quite simple and involves a straight length of something like 2"x3", a couple of small wood blocks and a clamp of the right size--maybe a 6" C clamp. I use one of those Irwin Quickclamps. It's big enough to fit and I can exert enough pressure with one hand to easily put the neck into a backbow, while holding everything together with the other.

202dy · #8 01-30-2009, 11:48 AM

The truss rod requires tightening and not loosening. That is as it should be right now. As you pointed out, wood shrinks and swells with the weather and humidity. Right now it is heating season in in the north east. If you have a humidifier in your home it will mitigate some of the problem. Otherwise the humidity levels aren't going rise much before spring. At that point you may find that it requires a twist in the opposite direction. All of this is especially true with a new instrument. Right now the retailers (who care about the instruments in their custody) are going nuts trying to keep the new guitars playing in top shape.

Here is a link to a thread from a couple of weeks ago. Scroll to the bottom to see an example of the clamping rig 62bass is talking about in his excellent post.

62bass · #9 01-30-2009, 12:06 PM

Thanks for doing that 202. The clamp set up at the bottom of page 1 of that thread is basically what I use and it also has specifics on washers and pads to prevent marring the finish.

I think some of that and a few other threads should be in a sticky here because this problem is coming up a lot this winter.

I may have to do this on a Squier 50s P bass I got recently. I've adjusted the truss rod by tightening it 5 times since the heat came on in earnest when the cold weather started. It's finally settled down and hasn't required adjusting for 3 weeks. But I may have to do the washer thing down the road. For sure I'm going to have file down the terrible fret sprout. I've already done that on my other older basses years ago.

It sort of goes with the territory when you live in a climate like this in an old house with no humidifier.

tranceFusion · #10 01-30-2009, 12:33 PM

Quote:

Originally Posted by Slowgypsy

Is this a new bass? What I mean is... if you just got this bass a few months ago, and you've found yourself giving a little tweak every month, I'd say the neck might just be settling in.

The serial # indicates it is an 08. I've had it since April of '08. I guess of course it could have been manufactured prior to that and tagged as an 08.

Quote:

Originally Posted by Slowgypsy

If this is a bass you've had for a while... how much do you turn the truss rod nut each adjustment? 1/8 turn? 1/4 turn? 1/2 turn?

The max I turn in a sitting is a quarter turn. Usually that takes care of it but if I needed to, I will give an extra little twist the next day.

Quote:

Originally Posted by Slowgypsy

Have you recently changed strings, say from a light gauge to a heavier high tension gauge?

Every time I change strings I adjust the relief, set the string height at the bridge, and set the intonation.

Quote:

Originally Posted by Slowgypsy

Has this instrument ever been professionally set up? Or do you do your own setups?

When I got the instrument I set it up myself and had my instructor look it over. He made a couple of tweaks to it. He is about the most competent that I have found in this area, though he isn't working as a luthier so I don't try to pester him constantly with it. I got tired of paying the local shops to keep my bass for a week and do a crappy job every time I changed strings or got a new bass.

I feel like I am perfectly capable of setting relief, intonation, string height, etc. but when I run into something that I think is a problem, I come to this forum

Quote:

Originally Posted by Slowgypsy

If you could give answers to some of the above questions... I'll check back here later on. But... yes... it is possible there is an issue with either the truss rod or the truss rod nut.

I have had the bass through the hot season and the cold season and have been tightening the whole time. Maybe I changed strings during the season change and I didn't notice that I had loosened it some, but generally speaking, between string changes, I have been tightening it.

It sounds like it is not slipping but there could be some other problem with the truss rod. I am thinking that since it is under warranty with Fender, I should discuss it with them, rather then making a bunch of modifications myself?

Thanks for the help, as always, guys!

Slowgypsy · #11 01-30-2009, 03:14 PM

It would seem that there is an issue somewhere. If you've been having to tighten the truss rod nut as many times as you have, over the length of time that you have... something is not as it should be. And I agree that if your instrument is still under warranty you should discuss this with Fender. Wish I could have had a better answer for you.

JLS · #12 01-30-2009, 05:00 PM

Quote:

Originally Posted by Slowgypsy

It would seem that there is an issue somewhere. If you've been having to tighten the truss rod nut as many times as you have, over the length of time that you have... something is not as it should be. And I agree that if your instrument is still under warranty you should discuss this with Fender. Wish I could have had a better answer for you.

With the further information, I'm going to agree w/the above post.

Solarmist · #13 01-31-2009, 03:39 AM

Quote:

Originally Posted by Slowgypsy

It would seem that there is an issue somewhere. If you've been having to tighten the truss rod nut as many times as you have, over the length of time that you have... something is not as it should be. And I agree that if your instrument is still under warranty you should discuss this with Fender. Wish I could have had a better answer for you.

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