Truss rod has needed constant adjustment for years. What now?

ersheff · #1 02-19-2013, 09:41 AM

Hello.
I've had to adjust the truss rod on my 12-year-old MIM jazz bass constantly for a long time. Pretty much ever since I got it.
It's especially bad when the seasons change, but I keep an allen wrench with me at all times to make adjustments as needed. Sometimes every time I play.
I have a luthier friend who, when I explained the situation to him, said "some necks are just like that".
So, what should I do? I mean, I could just deal with it and make the constant adjustments like I always have. But is the ultimate fix just going to be a new neck? My impression is that I just got unlucky and have a lame ass piece of wood for a neck.

Rip Topaz · #2 02-19-2013, 10:49 AM

There must be something that is holding you to that particular bass. 12 years is a long time with one instrument (well, for ME it is!!), there must be a reason.

I'd either search out a replacement with the same profile, or just live with it.

ersheff · #3 02-19-2013, 11:18 AM

Indeed there is!
My pops bought it for me. It was the last green MIM Jazz bass available at the time (they'd discontinued the color).
He's not dead or anything, but I vowed never to part with that bass. I like the color, I've got a Badass II and Lindy Fralin pups in it. I would rather replace the neck than get a new bass.
My inquiry had to do more with whether or not there was a different solution. I.e. is there some way to treat or setup this neck so that it's not changing so much?

Rip Topaz · #4 02-19-2013, 11:28 AM

Not really. Other than store it away from heaters and stuff like that. Either keeps adjusting as needed, or get a new neck.

ersheff · #5 02-19-2013, 11:34 AM

I'm supposed to inherit his '70s P-bass sooner or later (hopefully sooner!), so maybe when that happens I'll actually take the opportunity to put a fretless neck on the j-bass!

Bruce Johnson · #6 02-19-2013, 12:00 PM

Actually, there is a way to fix necks with instability that isn't too complicated. It doesn't work in every case, but usually will greatly reduce the movement.

My guess is that right now, the truss rod is fairly loose. That is, as you are making your correction adjustments, it isn't taking much torque on the wrench to turn the nut. Am I right? That's a common symptom of necks that have developed a small natural back bow, and have gone into the "dead zone" of the truss rod's adjustment range. That tends to make those necks extra sensitive to temperature and humidity changes.

The fix involves re-leveling the frets, and possibly the fingerboard, but with the truss rod pre-tensioned. That is, you tighten up the truss rod to about half it's maximum load. This will pull the neck into some amount of backbow. With the neck loaded like that, you recut it to flat. If it's not too much, it can be done by leveling the frets; the frets in the middle will end up a little lower in height. If the backbow while loaded like that is more dramatic, then the frets need to be pulled, and the fingerboard surface is trimmed to flat, then the neck is refretted in the usual way. What this does overall, is to get the truss rod working in its correct range, so it can do its job. Right now, the truss rod is loafing, and the wood is free to move around however it happens to feel that day. A common thing in many otherwise nice old Fenders.

Most Luthiers will charge you $100-$300 for the job, depending on how much work is needed. Sure, you can buy a cheap neck for that. But this is a nice old bass with sentimental value.

ersheff · #7 02-19-2013, 01:17 PM

Ah, interesting.
You're right, it's not difficult to adjust the truss rod.
Seeing how much work is involved, I wonder if this almost makes it a good candidate for a defretting?
I mean, if the frets have to be redone anyway and the fretboard maybe has to be relevelled, seems like I could just go all out with the fretless conversion.

Pilgrim · #8 02-19-2013, 03:03 PM

Why not replace the neck? You'll still have the instrument but not the problem. A MIM J has no collector value so you're not altering the value - except possibly improving it by eliminating a problem.

alembicguy · #9 02-19-2013, 03:17 PM

I have a 77 Fender Jazz with maple neck and blocks and binding that needs constant attention. The truss rod turns easily and though a pain in the rump it's worth the fiddling around as it can have the best action in the world. To me it's a small inconvenience to put up with something you love.

kellyrojo · #10 02-19-2013, 03:23 PM

http://www.allparts.com/Jazz-Bass-Ne...c_719-1-1.html

http://www.warmoth.com/Bass/Necks/StandardNecks.aspx

done

ersheff · #11 02-19-2013, 05:57 PM

Thanks, y'all.
I am not opposed to putting a new neck on it.
I am not opposed to just having to adjust it all the time.
I am also not opposed to having it worked on some day (either as a fretted or fretless conversion project) to make the truss rod "stable".
Getting Bruce's input about it potentially being fixable was very valuable.
As I'm happy with the overall feel of the neck, it might be worth doing the truss rod fix and fretless conversion someday, rather than spend the money on a fretless neck that I might not like as much. Especially if my luthier friend is willing to take it on for not too much dough.