Which truss rod wrench for a 78 Jazz bass?

Discussion in 'Hardware, Setup & Repair [BG]' started by SF_Bassist, Feb 5, 2014.

  1. SF_Bassist


    Dec 15, 2011
    Can someone confirm for me what is the correct size allen wrench to use for adjusting the truss rod on a 78 Fender Jazz bass?

    On mine, the 9/64th wrench seems too big and 1/8 fits loosely in the nut. I assume the allen wrench should fit snugly in the nut. I have confirmed the nut is not stripped.

    I want to proceed cautiously with this as it is my first truss rod adjustment.

  2. pfox14


    Dec 22, 2013
    should be 3/16"
  3. dju


    Jan 15, 2014
    p.s., I noticed that when the bullet nut was not on the bass the allen wrench felt nice and snug. My original bullet nut felt loose so I replaced it. and when I installed the new one it felt loose. and the old one when removed felt better than when it was installed. I wonder if something gets in the way after it has been tightened up and prevents the allen wrench from completely inserting into the nut.

  4. SF_Bassist


    Dec 15, 2011
    Thanks for the replies. I threw caution to the wind and tried the 1/8" wrench. Using less than an 1/4 of one turn to loosen the rod, the clanking sound is now gone. So far, everything seems fine. The nut turned easily and without much force.