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Epiphone Les Paul Traditional Pro-II Truss Rod Nut Size

Royal Blue

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What is the correct size Allen wrench that should be used for the Epiphone Les Paul Traditional Pro-II Truss Rod Nut?

Please don't say 4 mm because 4 mm is too small.  Matter of fact, here are the ones I've tried that are "close" to fitting with their results.

  * 4 mm - the suggested size from what I can find - Slides all the way in, but has about 30 degrees of play.  Too much play that I will not risk trying to rotate the truss rod nut since that will strip it out.  I can feel the the key slide in to the hex part so I know it is in there.
  * 4.5 mm - goes in to the center of the nut where it is round (see photo below), but it will NOT go in to where the hex part is.  This is too big.
  * 3 mm - way too small, turns freely when all the way in.
  * 1/8 Inch (3.175 mm) - way too small
  * 9/64 inch (3.571875 mm) - way too small too - turns but catches slightly
  * 5/32 inch (3.96875 mm) - too small too. Catches but still a lot play like the 4 mm
  * 3/16 inch (4.7625 mm) - way too large
  * 11/64 inch (4.365625 mm) would be the next size larger than 5/32 but they do not make that size (I've searched for hours). I've also seen this size referred to as 4.4 mm on a few Allen Wrench charts.  Some charts "claim" this is a valid Allen wrench size, but I'm guessing it has not been made for decades.  The next 1/64th step up from that would be 3/16 which is too large.
I've checked the nut to ensure that it was not stripped or rounded, and the edges do look straight and smooth.  I've included a photo, which was not that simple to illuminate and it looks kind of grainy due to zoom factor.  But I think its clear enough to show the hex edges are clean and not stripped/rounded.
Is there a such thing as an odd (non-standard) sized Allen wrench that is actually used to make the adjustments?  If so, who sells them and what would be the proper size that they would go by? 
I've wasted at least a good 6 to 8 plus hours trying to figure this out and at this point I would not be too surprised if this may be an one-off anomaly.
Thanks greatly for any and all help that you, or anyone else, can provide,

Image 2019-10-18 00_38_15 001.png

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Thanks Yorgle.  That's actually what I've been thinking about doing.  Will pickup a sacrificial 4.5 mm later today and then run a few light passes over the grinder.  So the end result will be that it will finally get adjusted.

But it still is leaving me with a few huge questions? 

What does Epiphone expect everyone to use? 

They build them to be adjustable, it's expected to be adjusted, and someone out there does adjust them.   So what do they use?  Is everyone expected to make their own tools when buying an Epiphone?  I honestly don't know.

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  • 2 years later...

Just got an Epiphone LP Traditional Pro IV. Was having trouble with the truss tool size. I have a high quality 4mm, but it has a bit of girth to after the actual 4mm part (see pic). So I believe it was getting blocked in the tunnel before getting into the socket. I removed the strings to gain better access. Eventually a cheap 5/32 hex wrench worked, couldn't find my cheap 4mm (5/32 = 3.97mm). It appears the tunnel before the socket is a bit long, so it takes some wiggling to get it seated. Take off your strings, take your time and make sure you feel that it goes in while wiggling. Also, loosen it first before going the other direction, that helps ensure you feel it is seated well.


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  • 4 weeks later...

Hi, was there ever a resolution  to this issue? I have a Epi Special II circa 2011 from Indonesia that just purchased second hand I want to adjust the truss rod for, and am having a similar issue with the truss rod hex wrench size. The nut seems in good shape and I can get a  4mm wrench to go in, but it feels very loose, and I feel like I might strip something if I try to force anything. 

Were you ever able to get your neck adjusted. Did you try grinding down that 4.5mm wrench to get it to fit properly? I purchased one myself, as well as a long handle 4mm wrench and when I get them, I'll try both to see if I can get either to work. In the meantime, any info anyone has would be helpful!

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  • 1 month later...
  • 1 month later...

Just FYI for anyone else with this issue, I finally found a solution. I purchased a Gripper 4mm truss from Stew Mac. It has a tapered end that ranges from slightly smaller than 4mm to slightly larger. It is designed for truss rod nuts that are damaged or stripped, but worked well for this situation. I was able to adjust the neck relief with no problem. 

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  • 11 months later...

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