You can try the "flat with set screw" idea but it didn't work for me. I ended up peening the anchor end as stated in a previous post. Others weld it. There is ALOT of stress on that anchor/truss rod connection.
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My Truss Rod Repair
- Thread starter 72LML
- Start date
You can try the "flat with set screw" idea but it didn't work for me. I ended up peening the anchor end as stated in a previous post. Others weld it. There is ALOT of stress on that anchor/truss rod connection.
Actually I'm an Manufacturing Engineer that can stumble my way around a Bridgeport. If it gets too complicated I pass it off to few of the guys in the shop that can do the real magic. I'm always amazed at some of the stuff they can do.
That's what I'm afraid of. Not only are you dealing with forces trying to pul the truss rod out of the anchor there is also a twisting force involved.
It's always nice to work at a shop that allows you to do "government work".
LOL! exactly.
I just had one of the truss rods i got from Martin Keith shortened 1/2" by our machine shop. Just had them make 2 additional welds a little further up from the end and then chop off 1/2" from the end.
This one is going in my Squier P neck that could have other wise been saved with the StewMac truss rod rescue kit, but I'm not ready to drop that kinda cash.
Here is a little concept that I threw together this morning. I need to finalize the tolerances and confirm the overall length but it should give you a basic understanding on what I would be looking at doing. The rod would have a flat milled on it and it would be held in place with a 3/8-24 set screw with Loctite. I may also mushroom one end of the rod to make sure it can't be pulled through the nut. Once everything was secured in place (and tested to make sure it works!) I would make a .750 dia x .1 cover to fit over the top of this and epoxy it in place. Hopefully the only tell tale sign of the repair would be the plugged drilled hole in the end.
I also confirmed that the thread on the end of the truss rod is a 12-28 thread. Talk about an odd ball. Most fender threads seem to be 10-32 but I suppose with the 5-string neck they increased the size of the rod for the added tension. Goofy thing is, is that they increased the size of the rod but not the OD of the nut itself. So even with the added tension they've reduced the size of the shoulder that the nut rests against.
I also confirmed that the thread on the end of the truss rod is a 12-28 thread. Talk about an odd ball. Most fender threads seem to be 10-32 but I suppose with the 5-string neck they increased the size of the rod for the added tension. Goofy thing is, is that they increased the size of the rod but not the OD of the nut itself. So even with the added tension they've reduced the size of the shoulder that the nut rests against.
I think I would worry about removing too much of the rod to compromise strength.
What if you milled two opposing flats on the rod the length of the exposed plug and created a steel plug with a slot that slipped over it?
The rod would rest with the flats perpendicular to the FB so the slotted steel plug slips right over it.
I only suggest it because it would be less tedious to make and you would preserve more material to help with the strength of the rod.
What if you milled two opposing flats on the rod the length of the exposed plug and created a steel plug with a slot that slipped over it?
The rod would rest with the flats perpendicular to the FB so the slotted steel plug slips right over it.
I only suggest it because it would be less tedious to make and you would preserve more material to help with the strength of the rod.
- Jun 28, 2005
- 1,015
- 18
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- Builder,mcdcustomguitars
Removing the fret board on most Fenders will not work. The truss channel was milled from the back side.That is why it has the "skunk stripe" . Also, the channel is not straight but it bowed, that is why your truss rod had the curve to it. Install the new rod, insert into a double threaded barrel with a set screw locking the rod to the barrel. IHMO
This is one of the things I tried and the truss rod snapped right where the dimple was. In order to get the cone tip set screw to go deep enough to make enough contact, you have to drill almost halfway through the rod.
The only way I've ever seen this connection made is either by welding the rod and the anchor together (new school) or peening the end of the rod (old school) into a dimple created on the heel end of the anchor (that's after the rod is already threaded all the way through the anchor with a bit hanging out the heel end).
I made a little progress today and got the new plug made. Looks like I'll need to trim a little bit off the end of it to make sure it's flush with the .750 counter bore. Otherwise it's coming together nicely. Tomorrow I'll get the end of the rod threaded, trim it to length, and get the flat milled on the end. Hopefully I'll be able to put it together and test it out this weekend. 
As for putting a flat on the end and weakening the rod....yes it will weaken it. But in theory as long as I have a larger cross sectional area than the minor dia of the threads it will still be stronger than the threads. So if something would happen to break it would be the threaded area again (in theory 
)
(Yes I'll be putting a new insert in the plug, this was one that we had laying around at work for checking the threads)
(The threaded insert in this pic has not been tightened down yet. It will be flush with the top of the plug once it's installed.)
As for putting a flat on the end and weakening the rod....yes it will weaken it. But in theory as long as I have a larger cross sectional area than the minor dia of the threads it will still be stronger than the threads. So if something would happen to break it would be the threaded area again (in theory )(Yes I'll be putting a new insert in the plug, this was one that we had laying around at work for checking the threads)
(The threaded insert in this pic has not been tightened down yet. It will be flush with the top of the plug once it's installed.)
I put the rod in tonight and got everything buttoned up. So far so good. The neck straightened right out when I tightened up the truss rod nut with no issues. Tomorrow after the Loctite and everything has a chance to settle a bit I'll throw some strings on it and give it a setup. Hopefully it works.
I did have to straighten out the hole in the end of the neck and enlarge it to 5/16" dia from 1/4" in order to get the new rod to slide in. Other than that it was pretty straight forward. Slipped the rod in through the heel of the neck and through the plug. Once it was on place I put some Loctite on the threads of the plug and tightened everything down.
If everything sets up ok I'll make a 3/4" dia cover for the steel plug and I'll plug the hole in the end with a maple dowel rod. The only thing that will give away the repair is the witness line around the wooden dowel plug. All said and done, much easier and cleaner that removing the fretboard.
Here are a few pics.
Here is a shot inside the heel of the neck. You can see the end of the rod. I added a small slot in the end of the rod so I could turn it with a small screw driver to line up the .150 wide flat on the rod with the plug.
Here is a shot inside the top of the neck. You can see the truss rod nut in place along with the truss rod in the center of it.
I did have to straighten out the hole in the end of the neck and enlarge it to 5/16" dia from 1/4" in order to get the new rod to slide in. Other than that it was pretty straight forward. Slipped the rod in through the heel of the neck and through the plug. Once it was on place I put some Loctite on the threads of the plug and tightened everything down.
If everything sets up ok I'll make a 3/4" dia cover for the steel plug and I'll plug the hole in the end with a maple dowel rod. The only thing that will give away the repair is the witness line around the wooden dowel plug. All said and done, much easier and cleaner that removing the fretboard.
Here are a few pics.
Here is a shot inside the heel of the neck. You can see the end of the rod. I added a small slot in the end of the rod so I could turn it with a small screw driver to line up the .150 wide flat on the rod with the plug.
Here is a shot inside the top of the neck. You can see the truss rod nut in place along with the truss rod in the center of it.
Looks good...I wish I had had access to a machine shop when I was doing my truss rod repair. Excellent job.
Also, you would've been bitterly disappointed when you got the fretboard off and realized the trussrod wasn't accessible that way...you would actually have to route the skunkstrip out....not a pleasant task...
Also, you would've been bitterly disappointed when you got the fretboard off and realized the trussrod wasn't accessible that way...you would actually have to route the skunkstrip out....not a pleasant task...
This has been a most enjoyable and informative thread. You did excellent work!
