Truss rod in mid '70s D-35

stormin1155

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I posted this over in Tech Shop, but traffic is pretty lite over there, so I'm putting it out here too..

I have a customer's mid '70s D-35 in my shop for a lot of work... bridge replacement, neck reset, cracks, headstock break, binding, frets.... Well I got it all back together, strung it up, doing the setup, and the truss rod won't straighten the neck. Nut turns... everything seems ok, but neck doesn't move. When I was steaming the neck joint, I noticed steam coming out of the truss rod opening by the headstock, and the whole neck got warm. This wasn't for an extended period. I only had to apply steam for 4 minutes to get the neck off, but I'm wondering if something happened in there...

What type of truss rod did Guild use in those? Simple rod in curved channel, or one of those straight ones encased in aluminum? I had one of the aluminum ones fail on a guitar because it got glued solid in the channel, and they have to move freely to work. I've never had a simple curved rod one fail other than breaking.
 

GardMan

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Can't put my finger in it, but seems to me I saw a pic of a 70s era truss rod and it was just a steel rod in a channel (were the aluminum-enclosed trusses available in the 70s?)... and I think I also recall hearing of one where the anchor in the neck block had failed, so rather than tightening, the whole rod just turned?

Make a mark on the end of the rod itself... when you turn the nut, does the rod turn with it?

Shoot a PM to Tom Jacobs (alias fixit) or dapmdave... they could probably tell you what the truss is.
 
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stormin1155

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Yes, I already marked the end of the rod. It isn't turning. I'll give Tom a shout. Thanks!
 

5thumbs

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If the truss rod itself is not turning when you turn the nut, it sounds like stripped threads on the rod (or the nut itself). Are you able to back the nut off to remove it? If so, most likely the rod is stripped. If it won't come off I would suspect the nut.
 

SFIV1967

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To continue what Rick already asked: In post 1 you say "the nut turns" (so it is not stuck) and in post 5 you say "the rod isn't turning". So if the rod isn't turning it would mean it is o.k., or? The truss rod is not supposed to turn. So if the nut turns, does it mean it turns and moves in the threads up and down as it is supposed to do or is the nut or the threads on the truss rod stripped?

Ralf
 

stormin1155

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Threads are not stripped. I added a couple of washers just to make sure I didn't run out of thread. Everything seems to work as it should except the neck doesn't move. I clamped it with downward pressure overnight and tightened the rod some more, and it seems to be holding. If it doesn't continue to hold I'll try heat and clamp. If that doesn't work I'll pull the fingerboard for further troubleshooting.

I'm wondering if when I steamed off the neck, and steam got into the truss rod channel it may have caused the mahogany to swell more than the rosewood causing the up-bow, and making it harder for the rod to do its work. If that is the case, time should solve it as the moisture equalizes.
 
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Westerly Wood

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I posted this over in Tech Shop, but traffic is pretty lite over there, so I'm putting it out here too..

I have a customer's mid '70s D-35 in my shop for a lot of work... bridge replacement, neck reset, cracks, headstock break, binding, frets.... Well I got it all back together, strung it up, doing the setup, and the truss rod won't straighten the neck. Nut turns... everything seems ok, but neck doesn't move. When I was steaming the neck joint, I noticed steam coming out of the truss rod opening by the headstock, and the whole neck got warm. This wasn't for an extended period. I only had to apply steam for 4 minutes to get the neck off, but I'm wondering if something happened in there...

What type of truss rod did Guild use in those? Simple rod in curved channel, or one of those straight ones encased in aluminum? I had one of the aluminum ones fail on a guitar because it got glued solid in the channel, and they have to move freely to work. I've never had a simple curved rod one fail other than breaking.

"I only had to apply steam for 4 minutes to get the neck off..."

on a Guild? that is amazing. I heard Guilds are tough to get the neck off. very interesting comment.
 

adorshki

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"I only had to apply steam for 4 minutes to get the neck off..."

on a Guild? that is amazing. I heard Guilds are tough to get the neck off. very interesting comment.

Yeah....
Stormin', I was the one guy who answered your original post in Tech, but now thinking you may not have seen it.
I didn't follow up here when you said the rod itself wasn't moving because that would have contradicted my initial suspicion anyway, that rod itself had become unanchored.
But that issue of steam travelling down the truss channel and out the adjustment slot still makes me think there's a problem, in the heel, although one would think that would make it take longer to break loose because the steam was escaping from the joint.
"Curiouser and curiouser"
I have a customer's mid '70s D-35 in my shop for a lot of work... bridge replacement, neck reset, cracks, headstock break, binding, frets.... Well I got it all back together, strung it up, doing the setup, and the truss rod won't straighten the neck. Nut turns... everything seems ok, but neck doesn't move. When I was steaming the neck joint, I noticed steam coming out of the truss rod opening by the headstock, and the whole neck got warm. This wasn't for an extended period. I only had to apply steam for 4 minutes to get the neck off, but I'm wondering if something happened in there...
Don't want to clog a thread with idle speculation but what you describe sure makes it sound like yes "something happened in there".
Sounds like some kind of crack is allowing steam to get into the truss channel.
Since the truss is anchored in the heel, that crack may or "whatever" it is may mean the truss is no longer anchored.
Also wondering if the headstock break may have been part of an incident that caused the truss to break loose?
Sorry to hear about the issue, figure it must not have been visible at the heel when you were prepping it for the re-set.
 
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stormin1155

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"I only had to apply steam for 4 minutes to get the neck off..."

on a Guild? that is amazing. I heard Guilds are tough to get the neck off. very interesting comment.

I've always heard that too, but the few Guilds I've done have come off relatively easy.

Yeah....
Stormin', I was the one guy who answered your original post in Tech, but now thinking you may not have seen it.
I didn't follow up here when you said the rod itself wasn't moving because that would have contradicted my initial suspicion anyway, that rod itself had become unanchored.
But that issue of steam travelling down the truss channel and out the adjustment slot still makes me think there's a problem, in the heel, although one would think that would make it take longer to break loose because the steam was escaping from the joint.
"Curiouser and curiouser"

Thanks. A thought occurred to me that I included in my edit above, but here it is again. Could it be that when steam entered the truss rod channel the mahogany took on moisture and swelled more than the rosewood (or whatever wood sits atop the rod in the curved channel), causing positive relief and making it harder for the truss rod to do its work?? If that is the case, giving it time for the moisture to dissipate should alleviate the problem.

Everything looked OK at the heel end. I could see the end of the truss rod, and nothing seemed out of the ordinary. Nothing about the headstock break would make me think it would have caused damage within the truss rod channel, but anytime there is trauma enough to cause breakage, who knows what damage it could cause in other parts of a guitar...
 

adorshki

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Thanks for your replies guys! A thought occurred to me that I included in my edit above, but here it is again. Could it be that when steam entered the truss rod channel the mahogany took on moisture and swelled more than the rosewood (or whatever wood sits atop the rod in the curved channel), causing positive relief and making it harder for the truss rod to do its work?? If that is the case, giving it time for the moisture to dissipate should alleviate the problem.
"ANYTHING's possible", although I'd be surprised if it swelled that much in only 4 minutes.
But I'm not a repair guy and have no experience in such things.
I wasn't even sure the steam escaping into the truss channel wasn't considered "normal", but I was pretty sure I'd never heard of it before.
Also, 'hog is supposed to be one of the most dimensionally stable woods (why it's great for necks), I'd expect the "filler" strip to be the more likely culprit even though results are same.
But I'm still thinking something's not right if steam got into the truss channel?
:friendly_wink:
 

SFIV1967

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But I'm still thinking something's not right if steam got into the truss channel?
Not sure how "airtight" that visible hole in the neck heel would be. In general it looks like it's normal that steam would go into that hole and further through the channel in the neck. Unless that end of the truss rod is fixed/glued in airtight.
Here's a D-25 picture as example:

picture8.jpg


Ralf
 
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adorshki

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Not sure how "airtight" that visible hole in the neck heel would be. In general it looks like it's normal that steam would go into that hole and further through the channel in the neck. Unless that end of the truss rod is fixed/glued in airtight.
Here's a D-25 picture as example:

picture8.jpg


Ralf

Thank you sir!
And yes, agreed, the caveat is "Unless that end of the truss rod is fixed/glued in airtight."
But can't see a reason why "airtight" would be a "necessity".
Just couldn't recall ever seeing a through-hole in the dovetail like that before, thought the truss was mounted into a blind tap from the other side.
 

SFIV1967

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Awesome picture, worth 1000 words ;)))
A video, even better! But it still does not show/answer the question how exactly the end is fixed in the neck block regarding if it is "airtight" or if steam can travel freely all the way though the neck.



Ralf
 
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