Eastman MD404 Truss rod question

[dcuttler]

I just received an Eastman md404, and found the neck relief to be a bit too much, so I started to tighten the truss rod, but I didn't get far before it stopped turning and felt like it was locked solid. It did reduce the relief a bit, but I want to reduce it a little more.

Here's the question. Is it possible that I ran out of thread? I'm thinking about removing the adjustment nut if it is removable and placing a couple of shim washers under it. So is it removable, and are there any surprises waiting for me?

Any thoughts would be welcome.

[rcc56]

If you bought it new, cease and desist immediately, and contact your dealer for warranty service. If your dealer won't handle it, contact Eastman directly.

If you do anything else, you will have voided your warranty, and will have a real problem if the truss rod turns out to be defective.

If you bought it used, take it down to Gryphon and let them take a look at it.

[dcuttler]

Thanks, but that doesn't answer my question.

[rcc56]

Since I don't know what kind of rod Eastman used, the answer is maybe. But if it's a dual action rod, you may be opening a can of worms if you try it, which is the reason for my previous advice. And if it's a single action rod, the answer is still maybe.

I'll add that if you didn't loosen the strings completely before your last attempt, you can loosen them now and try again and see whether it's still "locked."

If it is, then your best answer will come from Eastman technical assistance [if they will give it], rather than from a forum.

[meow-n-dolin]

I just received an Eastman md404, and found the neck relief to be a bit too much, so I started to tighten the truss rod, but I didn't get far before it stopped turning and felt like it was locked solid. It did reduce the relief a bit, but I want to reduce it a little more.

This might be a stupid answer, but, if you turned the truss rod much more than a half turn, you might have run up against the torsional strength of the neck (not sure of the "language" here). I did this once, set the instrument aside for a couple of days, then turned it another 1/2 turn. Rinse, and repeat. I never turn a truss rod more than a 1/4 turn at a time on a mando.

[dcuttler]

This might be a stupid answer, but, if you turned the truss rod much more than a half turn, you might have run up against the torsional strength of the neck (not sure of the "language" here). I did this once, set the instrument aside for a couple of days, then turned it another 1/2 turn. Rinse, and repeat. I never turn a truss rod more than a 1/4 turn at a time on a mando.

Thank's for the reply.

You may be correct. I have been thinking the same thing, because I believe the truss rod works by compressing the lower, while stretching the upper portion of the neck which is a hardwood, and probably can only move so much at a time.

I will check it again to see if it has relaxed a bit.

It's not critical, and the instrument plays well as it is, but I tend to obsess over stuff like this.

[mandocello8]

i am not shy to apply tool to mandolin, but turning the truss rod I would ask a professional (aka somebody who done it before). the neck will move, the geometry will change, as likely as not a high/low fret will ask for attention, the bridge may want to be raised/lowered, a nut slot may get unhappy, etc. a professional in a proper shop will deal with all this in 5 minutes, job done, $$$ exchanged, everybody happy. plus if there is a problem, they know numbers to call, mandolin cafe threads to consult, etc. (BTW, if people on this forum say "stop turning this dial, now!", do that).

[dcuttler]

Thank's for the reply.

You may be correct. I have been thinking the same thing, because I believe the truss rod works by compressing the lower, while stretching the upper portion of the neck which is a hardwood, and probably can only move so much at a time.

I will check it again to see if it has relaxed a bit.

It's not critical, and the instrument plays well as it is, but I tend to obsess over stuff like this.

You were correct. I just tryed it again, and was able to continue turning the truss rod nut. Obviously the wood is giving up. The gap is almost where I want it, 0.002 in. more and it will be perfect. Going to leave cover off and make another adjustment in a few days. That's some really hard wood!

Thank's for confirming my thoughts.

[meow-n-dolin]

You were correct. I just tryed it again, and was able to continue turning the truss rod nut. Obviously the wood is giving up. The gap is almost where I want it, 0.002 in. more and it will be perfect. Going to leave cover off and make another adjustment in a few days. That's some really hard wood!

Thank's for confirming my thoughts.

Glad it is working out!

[dcuttler]

I gave the truss rod nut 1 last tweak this morning, put the cover back in place, and am calling it done for now. It plays very well.

Thank's for the help meow-n-dolin