Truss rod stiff AF both ways

[Mrtoodamnsabre]

So basically I got a truss rod that only turns a half turn either way it’s an old pre eb Sabre, the action is great right now, if anything the neck is too straight. Earlier I was having trouble for a while turning it to straighten the truss rod and now I’ve discovered that there’s just as much trouble loosening the truss rod. Even weirder it appears that turning the truss rod counter clockwise lowers the strings and this is definitely not a reverse threaded bass!

my guess is that the threading on the truss rod by the top nut is jacked up, or the guys at the shop I took it to screwed it back on wrong and the truss nut isn’t turning much, and maybe the added tension between the nut is making it act in reverso mode.

anyways love this bass a lot and am not willing to risk blowing it up trying to get 1/64th of an inch higher, that’s what the bridge is for.

my real question is can I leave it the way it is, and bring it in to someone to probably replace the truss nut when the action eventually gets high and I run out of bridge to lower it out with? Is there any danger to the health of the neck leaving either an unlubricated or seized nut in there?

the counter lower, clockwise raise is kinda spooky but it might be because the neck is angled from a shim and the bridge height on the e is very very low. Other than that when I fret the neck at the first and 12th turning it counter clockwise appears to raise the action? Or it’s a very small amount and it’s hard to tell! Only got 1/2 a turn either way


Thanks again!

 

[FunkHead]

The threads may be damaged. Especially if you were turning truss rod nut with the strings tight and not manually straightening the neck to remove tension.

 

[Mrtoodamnsabre]

The threads may be damaged. Especially if you were turning truss rod nut with the strings tight and not manually straightening the neck to remove tension.

.
That’s what I was thinking, threads are gone, I hear rethreading or cleaning up the threads isn’t too huge of a deal though so that’s probably good!

 

[Mrtoodamnsabre]

Oh weird just got it to turn counter clockwise by removing the strings and turning it that way! I got my .5/64!!!

 

[Will_White]

Oh weird just got it to turn counter clockwise by removing the strings and turning it that way! I got my .5/64!!!

Yep truss rods are meant hold a neck straight not straighten them.

 

[GMC]

Yep truss rods are meant hold a neck straight not straighten them.

This is certainly true of modern 2 way truss rods. The older Fender Style pre-curved / bent rod would self curve as you tighten. The baked in curve would assist the rod in applying a curve as tension is increased. Older Aluminium box rods operated in a similar fashion, turn the Allen socket and you could see the neck move in real time. Some rods were tight, and a little turn created big effects, others were looser and needed a lot of turns to move the neck a bit. Each rod / neck was unique.
With the advent of Dual rods (the predecessor of the 2 way rods we see a lot of today), the rod thread is mechanically weaker. With these rods, they are effectively curve holders, not curve creators. Loosen, apply the curve to the neck externally...then tighten to hold that curve / shape. If you over tighten this rod expecting to see the neck move...you probably will just sheer the rod's thread because it's unable to exert that kind of mechanical force. The modern 2 way rods work on the same principle.
With the advent of Carbon fibre rods and multi laminate necks, the need for an industrial truss rod (or even dual rods) is becoming less and less. It's more of an issue with a neck made from single billet of maple, maple is relatively soft or bendy. A laminate with a stiffer wood like mahogany, purpleheart or wenge will increase the neck stiffness substantially. However, don't expect a modern 2 way truss rod to be able to bend a stiff multi-laminated neck just from the Allen wrench. I recently built a 34" scale six string and I just used a single truss rod and a 5 piece laminated neck using maple, wenge and purple heart. The neck is very stable, holds it tune and resists temperature changes really well.