Broken Truss Rod?

xavi1239

xavi1239

Feb 22, 2020
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5
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#1
Hi,

I just purchased a 84 japan Squier Pbass (A series). It came pretty well adjusted, with a correct relief. When changing strings I tested the truss rod and discovered that the truss rod nut was tightened to its maximum. That worried me, because I won't be able to reduce the relief if some day I need to (seasonal changes or if I change to higher gauge...)
At this point I tried to lose the truss rod. Surpisingly instead of making more bow, it remained the same and the truss rod nut unscrewed and fell out. It seems that instead of turning the rod anti-clockwise I have only moved the nut. I tried to move the treaded rod back and forth to see if it was lose at the other end of the the neck cavity, but it does not move.
Given that the old owner told me that he never adjusted the truss rod in 20 years I thought it only needed lube, so after unscrew the truss rod not I drop a few drops of oil in the threaded rod inside the cavity (2 times in 48 hours). It remains the same...

What's going on with this truss rod? It's broken or can be fixed?

Thanks!

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#2
Are you accustomed to adjusting truss rods? I ask because I wonder if the really has reached the end of its adjustment range. And it is not unexpected that the nut came off when you continued to loosen it. The truss rod does not turn - the nut does. I don't think your truss rod is broken.
 
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#3
Thanks for your reply.
Yes, I always adjust the truss rod in all my guitars and basses, but never had this problem before. You are right, the rod does not move, is the nut. I thought that maybe some washers as spacers could be the solution, but if I add a spacer then the truss rod nut will show up outside of the wood and the neck heel won't fit the pocket.

thanks!!
 
#4
The goal is to move the threads back from the end of the rod. You could grind the nut down a washer thickness and put a washer in. The result will be threads further back and the nut will stay in its groove.

That’s assuming the threaded rod is exposed enough to give at least three threads to catch the nut threads.
 
#5
Simple diagram of what happens here and what washer would do:
upload_2024-4-9_15-15-19.png

So, basically you need a washer or two which fits the TR hole in the neck but not smaller that the nut. Then the nut will tighten further. However, NEVER force-tighten it alone, first FLEX?BEND/HELP the the neck to go to the position you want and only then tighten the nut! It should go easily.

P.S. Smaller than needed washer (like I've pictured) might have greater pressure on wood behind it and break it in. It needs to be at least the same diameter as the nut.
 
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#6
That’s a single acting, single rod system and, as you’ve seen, only the nut moves. On a double acting double rod system the nut would be captive.

If it’s that difficult to turn especially with only a few threads showing, you’ll probably want to manually flex the neck into position then tighten the nut.
 
#8
Thank you for all your comments and suggestions. Indeed, even though the adjustment range may not be as wide as in double-action truss rod, with this one I can easily reach the sweet spot of the adjustment. The screw feels a bit stiff and I must admit I'm a little afraid of tightening it too much.
These Japanese basses exude character from every angle. The pickup is American-made and sounds really good. I'll definitely keep it.

Thanks!
 
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#10
xavi1239 said:
Hi,

I just purchased a 84 japan Squier Pbass (A series). It came pretty well adjusted, with a correct relief. When changing strings I tested the truss rod and discovered that the truss rod nut was tightened to its maximum. That worried me, because I won't be able to reduce the relief if some day I need to (seasonal changes or if I change to higher gauge...)
At this point I tried to lose the truss rod. Surpisingly instead of making more bow, it remained the same and the truss rod nut unscrewed and fell out. It seems that instead of turning the rod anti-clockwise I have only moved the nut. I tried to move the treaded rod back and forth to see if it was lose at the other end of the the neck cavity, but it does not move.
Given that the old owner told me that he never adjusted the truss rod in 20 years I thought it only needed lube, so after unscrew the truss rod not I drop a few drops of oil in the threaded rod inside the cavity (2 times in 48 hours). It remains the same...

What's going on with this truss rod? It's broken or can be fixed?

Thanks!

View attachment 5412086
View attachment 5412090

View attachment 5412091
Click to expand...


"Given that the old owner told me that he never adjusted the truss rod in 20 years"

I have to call BS on that. The truss rod nut is too chewed up for that to be true. I believe what the seller meant to say was "I have had to adjust the truss rod extensively over the last 20 years".
 
#11
60bass said:
"Given that the old owner told me that he never adjusted the truss rod in 20 years"

I have to call BS on that. The truss rod nut is too chewed up for that to be true. I believe what the seller meant to say was "I have had to adjust the truss rod extensively over the last 20 years".
Click to expand...
Given that it's a 40 year old bass who knows what happened the first 20 or if the the seller was even the original owner or if it sat in closet unused?
 
#12
Gluvhand said:
Given that it's a 40 year old bass who knows what happened the first 20 or if the the seller was even the original owner or if it sat in closet unused?
Click to expand...

I own a1960 Precision and the original truss rod nut shows zero wear. I'm mobile right now but will post a picture when I get to my PC tomorrow.

My experience (50 +years) with Fender bass guitars is that the truss rod nuts don't get to look like that unless they have been frequently torqued against the neck heel and forcing adjustments to a neck where the rod has been maxed out.

A competent luthier can fix that fairly easily provided the rod itself isn't damaged. Which I don't believe it is. I believe that the truss rod nut has been mashed up against the heel of the neck up inside the hole where the rod is. Caused by what I said earlier someone cranking on it and forcing it to try to straighten the neck.
 
#14
60bass said:
I own a1960 Precision and the original truss rod nut shows zero wear. I'm mobile right now but will post a picture when I get to my PC tomorrow.

My experience (50 +years) with Fender bass guitars is that the truss rod nuts don't get to look like that unless they have been frequently torqued against the neck heel and forcing adjustments to a neck where the rod has been maxed out.

A competent luthier can fix that fairly easily provided the rod itself isn't damaged. Which I don't believe it is. I believe that the truss rod nut has been mashed up against the heel of the neck up inside the hole where the rod is. Caused by what I said earlier someone cranking on it and forcing it to try to straighten the neck.
Click to expand...
I'm not saying the truss rod nut wasn't frequently torqued. I'm just saying it's a 40 year old instrument and all the truss nut wear may not have occurred over the last 20 years.
 
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#15
Gluvhand said:
I'm not saying the truss rod nut wasn't frequently torqued. I'm just saying it's a 40 year old instrument and all the truss nut wear may not have occurred over the last 20 years.
Click to expand...

Regardless of the amount of time that has passed, someone didn't treat that neck or truss rod nicely. Here's my 60 for reference. As you can see there's a slight bit of wear in the slots caused by my screwdriver. The tip is filed down so I can adjust the neck with out removing it. The tip fits in only one side of the slot but easily turns the nut. I just have to loosen the strings a bit and then loosen the neck screws to allow me to tilt it up a bit and adjust it. Thankfully, this neck is very stable and rarely requires any adjustment.

I've run into necks like the one you have and I've made them serviceable again. They make Small brass flat washers that will drop into the hole in the end of the neck to act like a spacer then I get a new truss rod nut and I put a little Vaseline on the threads then I screw it back in loosely. Then, I clamp the neck into a slight backbow and after I do that and while it's still under tension I tighten the truss rod up till it just contacts the washer and then just about a quarter turn more. Then hopefully if I'm having a good day when I put the strings back on they will either pull the neck into proper relief from the tension or I will only have to loosen the nut just a tiny bit to get the neck to come back where I need it to be. Sometimes you have to mess around with it a little bit till you find that balance where there's just enough backbow to where the string tension compensates for it. In the case where the threads on the end of the trust rod are stripped or messed up a competent luthier can repair that and save the neck and truss rod.

60date.jpg
 
#16
60bass said:
Regardless of the amount of time that has passed, someone didn't treat that neck or truss rod nicely. Here's my 60 for reference. As you can see there's a slight bit of wear in the slots caused by my screwdriver. The tip is filed down so I can adjust the neck with out removing it. The tip fits in only one side of the slot but easily turns the nut. I just have to loosen the strings a bit and then loosen the neck screws to allow me to tilt it up a bit and adjust it. Thankfully, this neck is very stable and rarely requires any adjustment.

I've run into necks like the one you have and I've made them serviceable again. They make Small brass flat washers that will drop into the hole in the end of the neck to act like a spacer then I get a new truss rod nut and I put a little Vaseline on the threads then I screw it back in loosely. Then, I clamp the neck into a slight backbow and after I do that and while it's still under tension I tighten the truss rod up till it just contacts the washer and then just about a quarter turn more. Then hopefully if I'm having a good day when I put the strings back on they will either pull the neck into proper relief from the tension or I will only have to loosen the nut just a tiny bit to get the neck to come back where I need it to be. Sometimes you have to mess around with it a little bit till you find that balance where there's just enough backbow to where the string tension compensates for it. In the case where the threads on the end of the trust rod are stripped or messed up a competent luthier can repair that and save the neck and truss rod.

View attachment 5416021
Click to expand...
It's not my neck and my comment was in response to you not believing the truss rod wasn't touched in 20 years. Thanks for the lesson though. Maybe I'll finally learn something in my next 58 years. Or maybe you'll be here to learn me.
 
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