Truss rod: to lubricate or not

[Horsehockey]

So I was making a small adjustment of the truss rod in my two year old AMI….which I think so far as I know has a dual action rod accessed through the sound hole. I’ve made adjustments in the past on this guitar and only the initial adjustment involves resistance. Applied the 4 mm Allen wrench today and it was pretty solidly stuck in both directions. Still had string tension on, but that hasn’t been an issue in the past. So my question: I have a can of tri-flow light oil with a red straw. Would I be doing any good to apply a little oil at end of the truss rod hole onto the adjuster? My guess is no since I read somewhere that dual action rods should not be lubricated for some reason. In any case, I would appreciate advice from someone who actually knows what they’re doing with these fine instruments. I know I don’t.

[phavriluk]

And I don't know, either!

The scene of the crime lies behind that bolt head we turn to adjust the truss rod; the threads of the bolt need to be free to turn there in the threaded block and at the inaccessible far end. I don't know how the bare wood where the truss rod sits will react to getting a good dose of lubricant. I'd be asking an expert before I did anything irreversible, like spraying in lubricant.

[Horsehockey]

Originally Posted by phavriluk

And I don't know, either!

The scene of the crime lies behind that bolt head we turn to adjust the truss rod; the threads of the bolt need to be free to turn there in the threaded block and at the inaccessible far end. I don't know how the bare wood where the truss rod sits will react to getting a good dose of lubricant. I'd be asking an expert before I did anything irreversible, like spraying in lubricant.

Thank you for the input phavriuk. I agree with your analysis. Based on my Shadetree mechanic experience, it feels like I’m dealing with sort of a flash rust situation up at that threaded block. We did have a humid rainy spell here which proceeded my difficulty so I don’t know if that’s it or not. My natural inclination is to lubricate in this situation but with a guitar as you have pointed out we not only have accessibility issues with regard to the potentially rusted threads, but we have the wood contamination potential. I’m holding out for some more input. And possibly from my local technician as you have suggested wisely. Thank you for your input.

[rampix]

I've bought 2 different used guitars that had frozen truss rod nuts. I used a pipette to apply a single drop of penetrating oil to the top of the nut and was able to free both. The threads weren't corroded but the contact surface of the nut was. I removed the nuts and applied a tiny amount of lube to the inside threads thereby allowing the lube to spread on the truss rod threads without any chance of getting oil on the wood. Then I also applied a very thin coat of grease to the bearing surface of the nut. They both remained very easy to turn.

I don't know if this is a possible solution for your guitar, but it might be.

[phavriluk]

Rampix, your solution seems right to me for situations where there's a nut staring back at you, but OP's double-acting truss rod uses a Allen-headed shaft that threads into a (usually steel) block and there's no simple way of applying a drop to the threads directly. The threads are behind the bolt head. A dilemma.

[rampix]

Correct phavriluk, a Martin and a Gibson that both had nuts I could remove. Too bad his rod’s design prohibits that fix.

[redir]

I'm not familiar with AMI guitars but oiling a truss rod is always a good idea and when it's stuck it could be too late. The problem with what you are suggesting to do is you might make a bloody mess of the inside of the guitar. If you set up something to guarantee that the oil only goes where it is supposed to then I'd say ok. Is the neck removable? If so that would be ideal.

[Horsehockey]

Many thanks to all for your input. My neck is not a bolt on and not easily removable. At the moment, it appears to be remaining adjustable, but I have some concerns regarding long-term with no lubrication at the head end. We’ll see how things go over time, and whether or not anyone with prior experience with a dual action rod has found a way to address this issue. My thanks to you all.

[John Arnold]

By definition, two-way rods do not have removable nuts. As a result, lubricating them is not possible, short of removing the fingerboard.
That is but one of several reasons I stick with single action rods on my builds.

We’ll see how things go over time, and whether or not anyone with prior experience with a dual action rod has found a way to address this issue.

You best bet is to cycle it back and forth many times to see if the tightness eases up. You may find that it will loosen somewhat, especially if the cause was glue seeping into the works when it was installed.

[Horsehockey]

Originally Posted by John Arnold

By definition, two-way rods do not have removable nuts. As a result, lubricating them is not possible, short of removing the fingerboard.
That is but one of several reasons I stick with single action rods on my builds.

You best bet is to cycle it back and forth many times to see if the tightness eases up. You may find that it will loosen somewhat, especially if the cause was glue seeping into the works when it was installed.

Thank you. That’s the plan for now.

[RJVB]

The neck and fingerboard would both be hardwoods, right? I've sprayed both WD40 and a silicon-oil equivalent on the edge of an oak front door and ditto doorframe, where it would jam because of expansion under sunlight. Doesn't penetrate very far into the wood at all.

Supposing you can get the trussrod loose enough that you can get the WD spray tube more or less behind it, would injecting a bit of it really be so bad/dangerous? Just enough that you can feel the effect? Esp. if you keep the nut loose for a day or two afterwards, so the wood has time to dry?

[John Arnold]

Two- way rods are composed of two rods, one on top of the other. In many cases, the lower rod is rigidly attached to the nut, and is threaded on the opposite end. The whole rod turns when it is adjusted. It is not possible to lubricate those threads without removing the fingerboard.

[Fathand]

Originally Posted by John Arnold

Two- way rods are composed of two rods, one on top of the other. In many cases, the lower rod is rigidly attached to the nut, and is threaded on the opposite end. The whole rod turns when it is adjusted. It is not possible to lubricate those threads without removing the fingerboard.

Some two way rods can be pulled out from underneath the fretboard. I have started building some that way, but the neck (bolt on) has to come off. Almost as much work I suppose.

[Horsehockey]

Originally Posted by Fathand

Some two way rods can be pulled out from underneath the fretboard. I have started building some that way, but the neck (bolt on) has to come off. Almost as much work I suppose.

Question: Could a lubrication access port be built into the headstock of an acoustic guitar (outfitted with a traditional dual action truss rod accessed through the sound hole) and if so would it do any good? Curious.

[Fathand]

Originally Posted by Horsehockey

Question: Could a lubrication access port be built into the headstock of an acoustic guitar (outfitted with a traditional dual action truss rod accessed through the sound hole) and if so would it do any good? Curious.

The threads are near the soundhole on the rods I use. The ends near the headstock are welded together. For the rare times a truss rod needs lubricating, a port might be overkill. I wonder if a hole could be drilled in the hex socket though that might reach the threads?