Neck-Thru Bass truss rod adjustment problem

O

Oqlanth

Feb 6, 2015
17
4
4,531
#1
I recently bought a 5 strings neck-thru (35" scale,24 frets maple neck with laurel fretboard) Jackson bass online. The Jackson website said it has dual action truss rod. When I bought it, i noticed that it had been in his package (and probably in warehouse) since 2018.
The bass had banana bow (middle -10th-15th frets- are down and first three are up, also last few frets are slightly up). Interestingly, rest of the things for setup is seems quite ok except little intonation problem in D string.
I tried to make truss rod adjustment. first i tried clockwise, i heard click in the beginning, then the click sound disappeared. no matter how i much i moved it, a credit card still easily fit to the 7th fret -while pressing 1st and 12th frets-. interestingly when i move counter-clockwise, the string height at 7th fret gets slightly lower but the banana bow still stays. I even move till end counterclockwise -slowly-. no changes.
I gave up -and afraid to break something- and move the truss rod somehow 'mid' position -slightly more counter-clockwise-.
why truss rod adjustment doesn't work? and What can you suggest me? nearest luthier is something like 2500 kms away from me.
 
Last edited:
#2
Hi. I'd say it is not ordinary banana bow. More likely it is ski-jump. A kink in neck at the body joint or in neck-through designs - the place where neck transition into body part is happening. Truss rod is not effective in that area no matter how tight it can go.
Anyway, if the normal truss rod adjustment is not dealing with it - then it is a defect. Return the bass if possible. If you have to live with it - you might need neck serviced by warpedneck.com or any similar services.
 
  • Like
Reactions: RSBBass
#3
Based on your description, I'd heave that thing back into its cardboard box and ship it back ASAP. That thing just sounds like a lifetime of headaches to deal with. However, you really should get it to a competent luthier for assessment if you really like the bass.
 
#4
Thanks for answer.

Good thing is after I recheck it, the kink near the body disappeared, but the one in nut-head is still there.
I loosen the strings and put bass on nut, i don't have any hope but at least I have to try something.

I like the bass but the my main problem is that I bought the bass in Hungary, and the online shop (even it is a Hungarian website) is in Czech Republic, and now I am in another country. I have to go back to Hungary, carry back the bass, and have to find the cardboard box -which is probably in garbage- or decent packaging...Find my ex-flat mate who got invoice...But if even it is fixed, the problem will repeat again and again, it looks like the best idea... Do you know have any idea that Jackson got international warranty?
 
#5
One thing you could try, although I’m kind of guessing an answer, is check the neck with no strings and no tension on the truss rod. If it is a dual action rod there should be a point where it’s loose in between tightening and loosening. In other words, if you tighten the truss rod nut (clockwise) until there is some tension then loosen it so it’s free, the neck should be completely flat. If not and it’s a new bass your best bet might be to try and get it warrantied.

A side note, on a dual action truss rod, if you continue to turn counterclockwise it should start to develop tension again. This is forcing relief into the neck.
 
#6
Matt Liebenau said:
One thing you could try, although I’m kind of guessing an answer, is check the neck with no strings and no tension on the truss rod. If it is a dual action rod there should be a point where it’s loose in between tightening and loosening. In other words, if you tighten the truss rod nut (clockwise) until there is some tension then loosen it so it’s free, the neck should be completely flat. If not and it’s a new bass your best bet might be to try and get it warrantied.

A side note, on a dual action truss rod, if you continue to turn counterclockwise it should start to develop tension again. This is forcing relief into the neck.
Click to expand...

Today I was very surprised. After I tried to do what you said (and put bass on the nut), the ski-jump at nut almost disappeared! now there are very slight bow 23th-24th frets, and almost disappeared bow at nut. I don't know yet what will happen after I set strings back tight.
I will take photos before and after I set strings tights. Thanks for the advice! Hope everything will be ok because giving back to warranty will cost me almost the price of the bass plus time...
 
#7
Late update:
I sent the bass to a competent luthier. He said the neck was awful condition but it could be fixable. I was surprised that it took just a few hours.He called me back (I wasn't there, I have to work in far away town) a few hours later and said the neck wood was very soft so it takes harder for truss rod to work. I didn't know anything about 'softness of neck wood' or it's effect on neck bow, it is written maple neck with laurel fretboard on specs but it seems not all maple are same! :D I don't know what he did extra if he did to fix the bow. He also changed the strings from stock strings with nickel D'addrio with same thickness extra long scale (I wasn't sure if long scale will be enough or not due 35" scale plus Jackson's point head).
Well, more than a few weeks later my friend brought me my bass (the disadvantage of working in far away place!). The neck was (and still after 2 and half months) super straight! Unfortunately there is fret buzz in first frets in all 5 strings. It is probably due to low action or very straight neck. And even the luthier's word of softness, neck is still straight after 2 and half months and change in climate (it was in high moisture city and now almost desert like place!)
Moral(s) of the story: Don't buy a bass in rush, you probably may not check it. Don't like far away from a competent luthier, you will always need them. Don't panic, in 21st century many problems more solvable than 25 years ago.
And thanks again everyone for replies and advices.
 
  • Like
Reactions: rockinrayduke
#8
Oqlanth said:
The neck was (and still after 2 and half months) super straight! Unfortunately there is fret buzz in first frets in all 5 strings. It is probably due to low action or very straight neck.
Click to expand...
Now you need the some relief - loosen the TR nut a 1/4 turn or/and rise the saddles.
Anyway, I strongly advise to learn setup procedures by your own, it is not rocket science in the end :)
 
Last edited:
#9
vaesto said:
Now you need the some relief - loosen the TR nut a 1/4 turn or/and rise the saddles.
Anyway, I strongly advise to learn setup procedures by your own, it is not rocket science in the end :)
Click to expand...

Frankly, I tried to fix the bow with TR but after one full turn (i did it quarter turn by quarter turn) allen couldn't turned more, the TR hole just loosen and it just barely fixed the bow. That's why I stopped and sent it to a luthier.

By the way, I forgot to say that the instrument is this (well the one with mahogany body):
Jackson Guitars | Electric & Bass Guitars

This 'soft neck wood' is a new thing for me. The in specs it says that the neck is graphite reinforced. And it is not an actual neck-thru, it is 'set-through neck'. I didn't know that kind of thing existed before :D probably it is something newish or became more common in last decades.

Anyway, thanks again :) Next thing I will do is try to fix this fret buzzing with a little loosening of the neck. The problem for the bridge that i can't find correct tool for adjustment. It is probably allen but not sure. It seems i will learn with experience :)
 
You must log in or register to reply here.
Top Bottom
Back