String Height/Trussrod Problems

Discussion in 'Hardware, Setup & Repair [BG]' started by Superdave, Jan 4, 2006.

  1. Superdave


    Apr 20, 2003
    St. Louis, MO
    So this is the deal; I've got this Fender Jazz with a neck problem, which I'm assuming is due to the trussrod. The neck looks like it has too much backbow, so I tried tightening it up a bit, but that didn't fix anything.

    Notes above the 9th fret would buzz horribly, until I raised the string height. This fixed the buzzing, but left me with incredibly high action.

    How can I get the action to what I'm looking for, but still keep the buzz away?
  2. Blues Cat

    Blues Cat Supporting Member

    May 28, 2005
    Katy, Tx
    Loosen the TR to fix back bow. By tightening it you made it worse.
  3. Are you sure you aren't talking about "forward" bow? Backbow is when the truss is too tight and the neck is pulled back towards you while playing. Forward bow is when it is pulled away from you.

    Read the sticky info at the top of this section. The Gary Willis site will really help in understanding why we need to adjust truss rods, which way they work, and why you need relief in the neck... Some people still think that the truss is for adjusting action, but that's only a small part of what it does.

  4. Superdave


    Apr 20, 2003
    St. Louis, MO
    It was definately backbow, thanks for the tip.

    Mag, I read through the Willis guide, which led mke to think that you tighten the truss rod to lose the backbow. I didn't think it was too clear. Anyways, I loosened it, I didn't notice any immediate change, but I'm thinking it takes time.

    After I loosened the rod, I tried lowering the action as well, but that led to the same buzzing problem.
  5. Superdave


    Apr 20, 2003
    St. Louis, MO
    Alright, I've got an update..

    I look down the neck towards the bridge, and I notice that the neck looks straight, up until the 7th fret, where it pulls upward

    \_______ like that, only not as exaggerated.

    I take it this is too much relief?
  6. SuperDave:

    Usually when you can look down the neck and clearly see the forward bow as you've described, most times that's an indicator of a bit too much relief.

    One of the easiest ways to check this is to (first) tune your bass to proper pitch. Always check relief with the bass properly tuned.
    Next, holding the bass in a normal playing position in your lap, use your left hand to hold down a string at the first fret. Using your right arm's elbow, press the strings down until they are pressed against the neck, somewhere off the neck, near the pickups. By doing this, you're using a string as a straight edge. While holding the strings down like this, use your RIGHT hand to press the string down on the fretboard at about the 9th fret or so. Is there room for it to move up and down? If there is, that's showing you how much relief (bow) is in the neck. If the string does not move down at all, then the neck is either straight or could have a slight backbow in it. Although it might seem awkward doing this at first, it's probably the easiest and quickest way to check this without having to clamp a string down with a capo. But DO NOT lay the bass down and try checking like this. The simple act of laying the bass down will move the neck and give unreliable readings. You need to be holding it, without putting any stress on the neck that could move it one way or another.

    How much should it move? Since you're fairly new to this, I'd recommend no more than about a credit card's thickness. There's different recommendations from different manufacturers, and many players use their own set amount, depending upon their playing styles.

    So.. if you do this, and you have no more than a credit card thickness of relief, then you're good to move on to the next steps of setup. If it's more than that, then you're going to need to "tighten" the truss a bit more.
    If you have NO relief, then you'll need to loosen the truss a bit. By " A BIT" I mean about approximately 1/4" turn or so.

    If you need to tighten the truss, do yourself and your neck a favor and loosen all the string tension on the strings. Make your adjustment, then tune back to proper pitch. Wait a few minutes, then check the relief again.

    Good luck...

  7. Figjam


    Aug 5, 2003
    Boston, MA
    Since your notes 9+ buzz, tighten the truss rod.