How to tell if a truss rod is too tight

Alathea · #1 07-16-2012, 10:49 PM

How can I tell if a truss rod it too tight? Is there a way to oil one? I tweaked the truss rod of the D15 I got off of CL and it was REALLY hard. Like, I used a stubby allen wrench, long end in, and I had to use a pair of needle nose pliers to grip the short end just to get enough torque to get a 1/4 turn. Is that normal on a 7 yr old guitar?

DennisC · #2 07-17-2012, 12:50 AM

That's not normal unless is already as tight as it will get? Why are you adjusting the truss rod? Have you measured the relief? Is there a backbend in the neck?

Wade Hampton · #3 07-17-2012, 01:10 AM

Althea, that's generally a sign that the truss rod is as tight as it's going to get. By trying to tighten further you might break it.

At this point, probably the wisest course is to take the guitar by a guitar repair shop to let the repair tech take a look at it. It may be that you're trying to adjust the truss rod to correct the playing action when a saddle adjustment might the right course of action.

Or whatever. My point is that with the truss rod in this state, if you keep on trying to adjust it you might cause some serious damage, and it's time to let a pro assess what's going on.

Hope this helps.

Wade Hampton Miller

Dwight · #4 07-17-2012, 06:25 AM

Quote:

Originally Posted by Wade Hampton

At this point, probably the wisest course is to take the guitar by a guitar repair shop to let the repair tech take a look at it.

Wade gives good advice, truss rod adjustments can damage your guitar if done incorrectly.

Alathea · #5 07-17-2012, 07:58 AM

I didn't force it, it was just something that I noted. I got the guitar 2nd hand. I switched out saddles, sanded the new one to match the old one. At tuning, at the 14th fret the string height at low E was almost 2 quarters thick.

jpd · #6 07-17-2012, 08:11 AM

Quote:

Originally Posted by Alathea_Squared

I didn't force it, it was just something that I noted. I got the guitar 2nd hand. I switched out saddles, sanded the new one to match the old one. At tuning, at the 14th fret the string height at low E was almost 2 quarters thick.

I noticed my 000-15m a tad hard to turn also. But in no way is the 14th fret action that high. After all that saddle work etc., was the neck level? If not, there is work to be done.

pete12string · #7 07-17-2012, 08:12 AM

Maybe a neck reset? Sight down the fingerboard - it should line up with the bridge. Check out this link for information on how to tell if your guitar could use a neck reset. http://www.guitartips.addr.com/tip97.html

Tone Gopher · #8 07-17-2012, 09:15 AM

Quote:

Originally Posted by Alathea_Squared

I didn't force it, it was just something that I noted. I got the guitar 2nd hand. I switched out saddles, sanded the new one to match the old one. At tuning, at the 14th fret the string height at low E was almost 2 quarters thick.

Don't match the old saddle if it's height is wrong.

The truss rod is NOT for adjusting action height - it is for adjusting neck relief.

If the truss rod nut is difficult to turn, consider removing it and giving it proper lubrication.

Misty44 · #9 07-17-2012, 09:55 AM

As noted, check the neck relief (i.e. the straightness of the neck relative to the nut and saddle and the gap between the strings and the neck), which the truss rod can adjust if required. Saddle action and neck resets are unrelated and have no direct relationship to the truss rod.

To measure relief, fret the string on the 1st and last fret of the neck (usually 14 or 12) - use a capo on the 1st to free up a hand to measure the gap between the string and top of the 7th fret using automotive feeler gauges.

But as Wade said, given the situation it's time for a skilled eye to take a look.

PorkPieGuy · #10 07-17-2012, 10:29 AM

Quote:

Originally Posted by Misty44

But as Wade said, given the situation it's time for a skilled eye to take a look.

I third this motion.

BradHall · #11 07-17-2012, 10:53 AM

I am doing a neck reset myself. I am ready to re-glue it to the box and this thread got me to thinking about the truss rod. The one in my old Alvarez 12 string is tight to the clockwise direction. Should I loosen it to about center adjustment before I re-glue the neck back on? Thinking this will leave some room for adjustment in the future. It is a headstock nut type of rod.

steveyam · #12 07-17-2012, 11:16 AM

Hmm. The truss rod NUT being tight may or may not be an indication of how much the truss rod is tightened or overtightened. They can just be 'tight' sometimes. Sure, if someone keeps winding it up, it's gonna get tight and something is going snap eventually. The real issue is the 'straightness' of the fretboard. I say straightness, though in practise a touch of 'relief' is the norm (forward bow, concave bend). Ok. Now, if anyone has no experience of adjusting truss rods and particularly if they have no engineering experience, I suggest they leave well alone, and take the guitar to a qualified repairman/guitar technician.

Moving on from that, if, having found out that the neck does need adjustment by way of tightening the truss rod to cure too much forward (concave) curve, and it's found to be tight (hard to tighten), this is what to do. Remove the truss rod nut. Obtain a suitable washer that will fit over the truss rod and drop it down into the gap it occupies. You may need to customise a standard washer to do this. In fact, get or make two of these washers. Grease the truss rod using a screwdriver to apply it all the way down to where it disappears into the end of the neck. Grease them and drop in the two washers. Grease the nut threads, put it back on and tighten it down to achieve the required amount of neck straightness/relief. Now, as the washers have been fitted, the nut may stick up and make it not possible to put the truss rod cover back in place. If so, remove one washer - hopefully you won't have to remove two. From thence on the truss rod should be much easier to adjust. When tightening a tight truss rod, you can also get a second person - someone who know what they are doing please - to apply some 'three point' back pressure* on the neck while you tighten it. That way, the nut isn't having to do all the work and is less likely shear the rod or grind to a halt.

* One hand at each end of the neck and a knee in the middle, pull back carefully, NO hands on the body of the guitar. And I stress - did I say stress? do not do this unless you know what you are doing, and in any case do not apply much pressure, just enough to help the truss rod nut do it's job in the hands of the person turning it. In short, if in doubt, skip the second person bit!

DanSavage · #13 07-17-2012, 11:24 AM

Quote:

Originally Posted by Alathea_Squared

How can I tell if a truss rod it too tight? Is there a way to oil one? I tweaked the truss rod of the D15 I got off of CL and it was REALLY hard. Like, I used a stubby allen wrench, long end in, and I had to use a pair of needle nose pliers to grip the short end just to get enough torque to get a 1/4 turn. Is that normal on a 7 yr old guitar?

Did you try to loosen the truss rod?

If I think I've run out of threads, I'll try backing off the truss rod.

Loosen it a half of a turn, then try tightening it again.

If it loosens easily, then tightens easily until it reaches a certain point, then you've reached the end of the adjustment and should not try tightening it any more.

Dan

the.ronin · #14 07-17-2012, 02:01 PM

Paging Charles Tauber ... potential improper truss rod adjustment application in aisle 7.

charles Tauber · #15 07-17-2012, 02:20 PM

Quote:

Originally Posted by the.ronin

Paging Charles Tauber ... potential improper truss rod adjustment application in aisle 7.

Several people have given good advice. There isn't anything that I would add but to suggest that prior to resorting to steveyam's two-person effort, it might make sense to try adjusting it first without string tension, to reduce the effort on the truss rod nut.

If one has run out of thread on the truss rod, adding spacers/washers might work. Lubricating the threads is never a bad idea, unless done in excess. As Wade suggested, it makes sense to have someone who knows what he or she is doing look at it, prior to trying a variety of things. I've adjusted guitars that required pliers to turn the truss rod nut. That, in and of itself, doesn't mean the truss rod is out of threads/tightened as far as it can go. But, it could be. That's why it makes sense to have someone who knows the difference look at it, which takes us back to Wade's response and my not having anything of value to add. Depending on the truss rod design, 1/4 turn is a big adjustment, which reinforces Wade's suggestion.