How to tell if Truss Rod is working?

[Spinal Tapper]

So I bought a 75 P bass from a Craigslist seller over the summer for a smashing deal. It's a great bass, but the strings could get a little lower for my liking...

I've adjusted the truss rod twice in 2 weeks, turning it once just a little over 1/4 turn with no result, and turning it again this time with a 1/2 turn with again, no noticeable result in neck relief...

Both times the truss wasn't very easy to turn, but it definitely turned for me. Before I give it another crank, I wanted to see what my fellow TBer's thought...

Would it be possible to turn a truss rod with no result? Also, it's not very deep in the neck pocket yet, maybe 1/4 inch. It should have more room to go...should I turn it again, or just take it into a tech and drop the cash on a pro setup...?

[joeyl]

before tightening again, I would take the nut completely out to get a feel for it, and to clean and lube the threads. Then tighten the nut back until just snug, and check the relief with the strings on. Now you have a reference of how hard you can tighten it, instead of going at it blind. And the lube should help, just make sure you don't get any on the wood inside.

[Spinal Tapper]

Originally Posted by joeyl

before tightening again, I would take the nut completely out to get a feel for it, and to clean and lube the threads...

Hmm, that kind of frightens me. How do you remove the nut? Just unscrew it out of the neck?

Might be better left for my tech, I suppose. I swear I'll never get the hang of this setup thing. They make it sound so easy, but there's always so many little nuances that make it seem so difficult...

[T-Bird]

Hi.

Yep, just unscrew it.

Doing a setup (/tweaking the neck) is not really that hard, but a tech will take care of the possible additional troubles that may surface.

Regards
Sam

[Spinal Tapper]

So, regardless of the nut, how can I tell if the truss is even working?

I mean, Ive turned the truss rod almost a full turn in 2 weeks...

Any diagnosis for this???

[202dy]

The way to tell if a truss rod is working is if the neck moves. Sometimes it takes more than a 1/4, 1/2, 2/3, 3/4, 7/8, 15/16 or a full turn to accomplish this. Sometimes it takes a lot more.

Spin the nut until the neck moves into proper relief.

If the nut is too tight, stop. You will know it is too tight when it squeaks.

[T-Bird]

Hi.

Originally Posted by Spinal Tapper

So, regardless of the nut, how can I tell if the truss is even working?

I mean, Ive turned the truss rod almost a full turn in 2 weeks...

Any diagnosis for this???

For starters, one should never test the TR by tightening it.

Even if less relief is required on an unknown instrument, it's often a good practise to back off the nut a bit and measure/view whether it has an effect or not.

Most, if not all, Fenders have a single acting "one piece" TR, that means there's plenty of thing that can be wrong, and more often than not, the TR thread runs out for one reason or another, and a washer or a two is needed in order to get back the full intended adjustability.

IMHO, and IMHO only, diagnosing a TR is not something that can easily be done over the keyboard of a computer, the repair person/tech/luthier has to have it in his/her hands.

Regards
Sam

[Spinal Tapper]

Solid advice, T-Bird. I'll probably just end up taking her into my guy...

[JehuJava]

Just had the same problem. I've been trying to remove a little relief from the neck to get some low action on an 08 Fender USA Deluxe Precision. I have some buzz in the upper register and have just over one mm of relief measured by a straightedge. I started by removing the neck, removing the TR nut and putting some grease in the nut, and tightening the nut to snugness. Then I made probably four quarter turns in two days time and my neck isn't budging. All four turns have been tough-ish. The fifth turn on day three produced a loud squeak and no neck relief change.

What do you guys think?

[Turnaround]

Originally Posted by JehuJava

Just had the same problem. I've been trying to remove a little relief from the neck to get some low action on an 08 Fender USA Deluxe Precision. I have some buzz in the upper register and have just over one mm of relief measured by a straightedge. I started by removing the neck, removing the TR nut and putting some grease in the nut, and tightening the nut to snugness. Then I made probably four quarter turns in two days time and my neck isn't budging. All four turns have been tough-ish. The fifth turn on day three produced a loud squeak and no neck relief change.

What do you guys think?

You need to learn more about setup or take it to a tech (you did ask what I think!). You don't address buzz in the upper frets with the truss rod.

[Turnaround]

"Why didn't anyone ever tell me bossa nova sounded so good?"

I didn't know anyone was listening. I've been preaching bossa nova since 1967.

[JehuJava]

Originally Posted by Turnaround

You need to learn more about setup or take it to a tech (you did ask what I think!). You don't address buzz in the upper frets with the truss rod.

I'm trying to learn

But this is exactly what the Jerzy Drozd setup guide says on page 28 figure 15...[sic] too much relief may result in buzzing in the upper registers...that was paraphrazed of course.

[Turnaround]

Several guides suggest that buzzing in the upper frets is caused by too much relief. That's an oversimplification of setup parameters. I can guarantee that if you have your bass set up so there is no buzzing, then you add more relief to the neck, it won't start buzzing in the upper frets.

I think what the guides are trying to say is that if you have too much relief, you may have lowered the bridge too much to try and compensate for the strings being too high off the fingerboard. If you lower the saddles too much you will get fret buzz in the upper frets. Therefore you should remove some relief and raise the bridge saddles.

In other words, if you want low action you have to balance all of the factors properly, i.e. relief, saddle and nut height, fret levelness.

[JehuJava]

Originally Posted by Turnaround

In other words, if you want low action you have to balance all of the factors properly, i.e. relief, saddle and nut height, fret levelness.

This what im trying to do. I lowered the bridge. Had buzz. Measured the relief and found the relief to be much more than the fender standard. To me this jives with the material I read from jerzy drozd.

My concern was the neck not moving and the loud squeak from the truss nut.

So. I loosened my strings to slack and let the neck alone for 24 hours. The neck staightened out quite a bit. I tuned to pitch and now my relief is between 1/2 and 3/4 of a mm. Making progress. I'll watch the relief with tension to see if it goes back.

[electracoyote]

Originally Posted by JehuJava

So. I loosened my strings to slack and let the neck alone for 24 hours. The neck staightened out quite a bit. I tuned to pitch and now my relief is between 1/2 and 3/4 of a mm. Making progress. I'll watch the relief with tension to see if it goes back.

Good move.

With difficult truss rods that won't straighten the neck, I have several times manually tweaked the neck while simultaneously twisting the rod. Sometimes string tension is enough to prevent the rod from doing its job. There are a few brand/model basses where you absolutely must assist the neck when twisting the rod, and because of that I'm now just in the habit of doing it with any bass. When you loosened the strings, you were assisting the neck in countering the tension of the strings.

I usually put the neck on my thigh (while seated) and let the weight of the body provide the counter, holding the bass level by the headstock. This is usually enough to gently and slightly bend the neck the direction you want it to go while twisting the rod.

Quarter turn at a time max, one reason being exactly what you are experiencing (stiff rod--no pun intended), another reason being the neck can only take so much at one time. Do give it a good 24 hours or so to adjust and settle.

Good luck with it.

[JehuJava]

I thought so too.

[bassman_al]

Hey thanks for this thread guys! I am working on a bass for a friend, Fender Jazz V 1999. Truss rod was really tight but didn't seem maxed. Tried the "over the knee back-bow" method and presto! Able to turn it enough for the low action I knew it was capable of! Wonderful bass now living up to its potential .35mm relief!