I need to adjust the neck on my Alvarez Yairi; the strings are getting too far away from the fret board in the higher frets.
My problem? I can’t for the life of me remember which way to turn the set screw.
Clockwise? Counterclock wise? I do (I think) remember it’s about a quarter turn every few days until the spacing is right.
Any guitar techs in this forum?
Thanks, CedricR.
Looking at the screw - clockwise will tighten, counter-clockwise will loosen. Sounds like you want to tighten. Loosen the strings, quarter-turn to half-turn and let it settle for a while, like a week as you mention.
Righty-tighty, lefty-loosey was the mnemonic I was told as a teenager.
Thanks! I really want to get this right without breaking anything. I’ve had this guiter longer than two of my wives so it’s a keeper! :D:D:D:D:D
I agree with Le Ministre that you need to tighten the nut (clockwise). I don’t think you’ll need to wait as long as a week to judge the results and readjust. When I adjust a truss rod to lower the action, I slacken the strings a bit, tighten the nut 1/4 turn, retune the strings and let the guitar settle for an hour or so. Most of the change that happens from tightening the truss rod happens right away; letting the guitar settle is a useful precaution against going too far, but the changes that happen during the wait are minuscule, in my experience. If, after and hour or so, I find that I need to make further adjustments, I repeat the preceding steps.
What **Crotalus **said - take it SLOW and let the guitar settle. And if you find you want to tighten it more than 3/4 to a full rotation, STOP and take the guitar to a local shop to have them check it out - you may not be doing something right, or there may be more needing adjustment on the guitar. Much more than a full turn is a recipe to send your guitar to a tech/luthier like Carson O’Genic, who would have to remove the broken truss rod now residing in your neck 
I will add that I have seen guitars come from the shop, brand-new, which had the nut on the truss rod loose, meaning that the rod was doing nothing to work against the natural tendency of the neck to become concave on the fingerboard side in response to the tension of the strings. This obviously doesn’t apply to the OP’s guitar, but those were examples of guitars where more than a whole turn was required to flatten out the fingerboard. Generally speaking, if you need more than a whole turn on an old guitar whose truss rod nut was already tight, you ought to have a luthier look at it, as WordMan said.
Has the bridge tilted and/or the top deformed?
“Deformed”?!?!? Deformed?
Bite your tongue, sir - classic old acoustic tops don’t “deform” - they “belly” - as in: “Boy that old pre-WW2 Gibson is in great shape - a couple of closed cracks on the back and a bit of bellying at the bridge, but it doesn’t need any work, and plays and sounds like a dream!”
It makes it sound so much more palatable, don’t you think? ;)
(note: **Carson **is right - deformation, or “excessive bellying” can really be a problem. There is a big difference between an older guitar that has settled in and the bridge darn-near getting peeled off because the top is being lifted by the strings…and it can certainly lead to strings and neck appearing to be out of true)
'Spose you’re right, there, though were I to use either term regarding the wife, I’d have a cracked headstock and a trussed rod.
On old acoustics, the top/ bridge giving under tension would be my first look. Truss rods on old guitars would be the last unless the player upped string gauge, or hasn’t paid much attention to pitch.
Lots of good info above.
One of the first guitar related books I bought back when I started, has over the years been worth it’s weight in gold for maintenance issues.
The truss rod adjusts neck relief, not the action (string height). Now it’s true that the relief and the action are related adjutments, but if the problem is that the action is too high because the neck angle is wrong or the top is bellying, adjusting the relief won’t fix the problem and will only risk screwing up the neck.
Here is a good tutorial on truss rod adjustment and where and how to measure the relief:
http://www.frets.com/FRETSPages/Musician/GenSetup/TrussRods/TrussRodAdj/tradj.html
To finish the thought I started, don’t adjust the truss rod because you think it needs adjusted, adjust it because you’ve correctly measured the relief and know it needs to be adjusted.