Tip: loose tuning machine gears on Fender MIM bass

Discussion in 'Hardware, Setup & Repair [BG]' started by JayfromDeeKay, Mar 10, 2012.


  1. JayfromDeeKay

    JayfromDeeKay

    Joined:
    Jun 23, 2009
    Since I had planned to tighten the tuning machines on my new Fender MIM standard jazz bass, I thought I might as well take a few pictures and post a little tutorial: :)

    If the tuning machines on your MIM bass feel loose and unprecise, the following tip will tighten them:

    First remove the strings from the headstock:
    [​IMG]

    A look at the back of the headstock.
    [​IMG]

    Get out your screwdriver and unscrew the large philips screw on top of the gear, and you'll be able to disassemble it:
    [​IMG]

    Let the tuning post drop away. Underneath the wheel you'll find two washers, a black plastic washer and a metal one. Their job is to make sure the gear's wheel and worm fit tightly together:
    [​IMG]

    Here they are, removed from the whorm-wheel:
    [​IMG]

    The metal washer has a slight bend to it. The more it is bent, the tighter the gear of the tuning machine will work. Now carefully bent the metal washer, so it is slightly concave:
    [​IMG]

    Now you just need to re-assemble the whole enchilada, and voila, your tuning machine will be nice and tight!

    If it is too tight now, you simply have to unbend the metal washer a bit.

    Remember this tip is for Mexican Standards only. AFAIK, the other Fender basses use another system.
  2. chinjazz

    chinjazz Supporting Member

    Joined:
    Sep 11, 2002
    Location:
    Atlantic Beach, FL
    Interesting! Thanks for the post!

    Just like a spring in a way.

    I'll see if I can figure how this works on Squires and post that.
  3. keyofnight

    keyofnight

    Joined:
    Jun 3, 2011
    Location:
    Seattle, Wa
    Excellent work. :D
  4. chinjazz

    chinjazz Supporting Member

    Joined:
    Sep 11, 2002
    Location:
    Atlantic Beach, FL
    Just checked and the Squire P Special has the same sort of mechanism. Maybe not the same quality material as Fender.
    Thanks again!
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  6. Craig_S

    Craig_S Banned

    Joined:
    Oct 15, 2008
    Location:
    Metro Detroit
    Nice tip!
  7. JayfromDeeKay

    JayfromDeeKay

    Joined:
    Jun 23, 2009
    Thanks, guys!

    Nice to know the Squiers are the same.

    Yeah, it would be nice if anyone could chime in on how the tension is set on the american and vintage tuning machines.
  8. rg07

    rg07

    Joined:
    May 18, 2012
    This worked for me somewhat. There still seems to be play in the turning portion of the key. In other words, I can tune the E string, then you can wobble the key a bit. Eventually, because of it, the string still goes out of tune. Anyone know of a fix for that, short of getting some hipshot tuners or anything.
  9. Steveaux

    Steveaux

    Joined:
    Jul 1, 2008
    Location:
    The Wilds of NW Pa.
    Always tune *UP* to pitch.
  10. Pilgrim

    Pilgrim Supporting Member

    Joined:
    Jul 8, 2004
    Location:
    Fort Collins, Colorado
    ^^That's the correct technique. Done correctly it works regardless of how sloppy the tuners are.
  11. megafiddle

    megafiddle

    Joined:
    May 25, 2011
    It's called backlash. It's the tiny amount of clearance between the gear teeth that make
    it impossible for the tuning key to have positive control over the tuning post.

    If you always tune up to pitch, you will have already taken up all of the backlash, and
    there will be no freedom for the post to slip back.

    If you tune down to pitch, friction might prevent the post from taking up the backlash
    as it follows the tuning key adjustment downward. The post can then gradually or abruptly
    take up the backlash later and the string goes flat.
  12. rg07

    rg07

    Joined:
    May 18, 2012
    Thanks for all the help! I will try that. So, it sounds like it isn't just my tuners.
  13. unclebass

    unclebass

    Joined:
    Dec 17, 2012
    Location:
    Southwest Louisiana
    I know I am dredging up an old post, but this information is very helpful. I have a 2011 MIM 5er that I just acquired that had the tuners, string trees, and pickguard painted. I have cleaned the paint from the pickguard. Lacquer thinner worked miracles. I plan on using the same thinner to clean the tuners. I will disassemble them one at a time and soak the pieces in thinner to get to the original chrome surface. Does anyone know if there is any material other than the metal of the tuners that I should not expose to thinner? It doesn't seem to make sense to me to replace the tuners if I can remove the paint and have them good as new.
  14. audioglenn

    audioglenn Gold Supporting Member

    Joined:
    Jul 14, 2012
    Location:
    Pennsylvania
    Great tip! Thanks for posting! It's a big help.
  15. unclebass

    unclebass

    Joined:
    Dec 17, 2012
    Location:
    Southwest Louisiana

    FYI...Only piece not chrome on tuner assembly is plastic washer shown on OP. Soaking in lacquer thinner worked great, and now function better than before. I even cleaned plastic washers with thinner, just didn't let them soak. Why would someone paint chrome tuners???

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