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Jacked up truss rod?

Discussion in 'Hardware, Setup & Repair [BG]' started by DrEvilBeer, May 22, 2002.


  1. DrEvilBeer

    DrEvilBeer

    Aug 15, 2001
    Honolulu, HI
    I usually don't post anything on TB, I just read,but I've come across a little problem I could use some help with.

    So I buy this bass from Samash.com that's closing out for $75. I get the bass, and it's a great deal for the money, but I noticed the neck is slightly bowed out (The opposite of how a neck should bow). So I attempt to adjust the truss rod. I turn it about 90 degress and let it sit for a day. The next day I attempt to adjust it again but it won't budge. I also noted that the neck didn't straighten out much form the 1/4 turn I had done the previous day. So stupid me, I attempted to force the truss rod to turn. This seems to have only jacked up the thread on my truss rod and effectively de-threaded it.

    Now I'm wondering why the truss rod is so hard to turn, and I'm wondering if anyone knows of a way to re-thread the truss rod so I can use some object... either an allen wrench or a screw driver or something, to turn it.

    Some other things to note... The bass is a neck-through. The truss rod is (obviously) adjusted at the nut. The neck apears to be 5 piece mahogany (3 pieces) and maple (2 pieces) with a rosewood fretboard.

    Thanks in advance!
     
  2. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA
    I am not sure what you are saying.

    Did you strip out the allen-head on the truss nut, or the internal threads on the rod itself?

    MOST of the time, makers use a softer metal for the truss nut than the rod itself. So, you are more likely to strip the nut than you are the rod.

    Whether you stripped the internal threads on the truss nut or allen head, you simply need to remove the truss nut and replace it.

    IF the internal threads are stripped, you might be able to still remove it by turning the nut the opposite direction.

    If the allen head it stripped, try to remove the nut by, again, simply turning it the other way. Relief the stress a bit by using your strength to bend the neck a bit.

    IF it is too stripped to be removed, try dabbing a bit of grinding compound on the allen wrench and setting it in the stripped hole with a few subtle hammer taps. Next I would find a slightly large hex key and tap that in with a hammer.

    Once you get the nut off, just thread the new one on and you are ready to rock. This time try helping the rod along by putting pressure on the neck as you turn.

    If you really did destroy the rod itself, remove the strings, drill a 1/4" hole through center of the body, install a small movement, and you have yourself a nice $75 clock.

    Chas
     
  3. DrEvilBeer

    DrEvilBeer

    Aug 15, 2001
    Honolulu, HI
    Appreciate the reply. I should have been specific in saying that I stripped out the hex thread on the top of the truss rod (I guess this is the truss rod nut, I wasn't aware that the truss rod was more than one piece). In other words where it used to be hexigonal in shape it's now much more round such that the allen wrench won't lock into it enough to turn the actual truss rod. I apologize for the poor explaination.

    So I assume this "truss rod nut" sits on the top of the truss rod and can be unscrewed from the truss rod itself?

    I'm having trouble understanding how to remove the truss nut. I'm unable to turn the nut in either direction because it's stripped both ways.

    The grinding compound solution you prescribed sounds like it would work. So I can probably pick this grinding compound stuff up at Home Depot and I just put this stuff around the allen wrench and leave it to set overnight and then I'll effectively have a new hex threading? Makes sense to me... That's a damn good idea. And if that doesn't work, as tongue-in-cheek as it might sound, your clock idea was good too.

    Thanks for helping a brutha out Chas!
     
  4. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA

    That is correct. I can draw it in two seconds, but I'll try to use words to offer a simple explaination of how a truss rod works (not all are built like this, but you'll get the idea):

    Take a straight neck. Bend it in relief. (Board on the inner part of the arc) While bent, get a really long STRAIGHT drill bit and drill a hole through the neck long ways. Remove bit, and loosen the bend. You now have a curved hole, and a straight neck because the neck was bent when the hole was drilled straight.

    Insert rod and secure at one end. Place a nut on the other. The rod, when loose, will follow the path of the curved hole, but as you tighten the nut, you are, in effect shortening the rod. This tension forces the "hole" to again straighten, which means it "bends" the neck.

    The tension of the strings bends the neck one way, and the tension of the truss bends it the other. So, a proper adjustment reaches the desired balance.


    No. Grinding compound is simply a metallic, gritty substance with a ton of "bite". By dabbing it on the hex key, it will sort of fill in the gaps created by the stripping and create more friction. Making it a little easier for the hex key to bite.

    It won't help to wait overnight. If that doesn't work, get a bigger hex key and tap it in with a hammer.

    When attempting to remove the nut, hold the neck between your knees and use your other arm to force a SLIGHT additional amount of relief in the neck. The will take pressure off the truss nut and make it easier to free.

    You will certainly need to replace the truss nut when you get it off.
     
  5. DrEvilBeer

    DrEvilBeer

    Aug 15, 2001
    Honolulu, HI
    Thanks for the info. I wasn't aware of exactly how a truss rod worked, I just knew that it did.

    One last question though... Does the nut screw off of the truss rod or is it just placed on top of it? Am I just trying to pull it off by "lifting" upwards or unscrewing or what?
     
  6. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA
    Unsrew it. Turn it the opposite direction (counter-clockwise) and it should screw off.

    Chas
     
  7. DrEvilBeer

    DrEvilBeer

    Aug 15, 2001
    Honolulu, HI
    I really appreciate all the help.

    God bless.