To make truss rod set-up and adjustment more convenient, Modern construction necks feature the Gotoh side adjustment mechanism. Inserted between
the usual truss rod adjustment nut at the heel and the truss rod, this ingenious device uses inclines and wedges to make small rod tension adjustments.
Initial set-up is still accomplished at the traditional butt end, but future small adjustments are then conveniently done on the side of the neck.
Unfortunately Gotoh does not offer these mechanisms left-handed. Lefty Modern necks only offer heel adjustments on straight necks,
and peg-head adjustments on angled necks.
The factory setting on a new neck is with the side adjustment mechanism centered within its operating range. To adjust your neck for the first time, use the following steps:
Tighten the heel-adjust nut (See A) until the fretboard is perfectly flat. At this point the side-adjust bolt (See B) should be recessed into the heel approximately 1/16" (2mm).
- Attach the neck and tune the strings to pitch.
- Check the neck relief. Detune strings and make the necessary relief adjustment using the side-adjust bolt and supplied allen wrench.
- Tune the strings to pitch. Repeat steps 3 and 4 as necessary.
- Never loosen the side-adjust bolt so far that it protrudes from the side of the neck. If it is completely removed it may be very difficult to re-install.
- Never adjust the neck under full string tension - always de-tune the strings first.
Only moderate force is required to operate the side-adjust mechanism. It is possible to damage it if excessive
force is applied after the bolt has stopped at the bottom of its travel (it would be recessed approximately 1/4" at this point). If the side-adjust bolt is recessed and there is a large amount of resistance, STOP and re-set it as outlined below.
Fully tightening the side-adjuster so that it stops will also lock the action of the heel-adjust nut. Do not attempt to tighten the heel
nut when the side mechanism is locked.
Side-Adjust Reset Procedure
Most necessary relief adjustments can be accomplished using only the side-adjust. If you have completely tightened or loosened
it and still need to make further adjustments, you may need to reset it by removing the neck and following the steps below:
- Completely loosen the heel-adjust nut.
- Turning clockwise, tighten side-adjust bolt until it stops.
- Back side-adjust bolt out 7 (seven) complete turns. This will center it in its best operating range.
- Tighten heel-adjust nut until fretboard is perfectly flat (has no forward curve).
- Attach neck and tune to pitch. Detune strings and make necessary relief adjustment with side-adjust bolt. Repeat as necessary.