Replacement Truss Nut for a 70's Memphis Brand Precision Bass.

H

harrumphicus

Jan 13, 2017
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#1
Hey, I've heard around the internet that this is the place to ask. Search showed a couple of other threads on Memphis basses, but nothing about the truss rod nut. I need to replace the one on my Memphis P-bass. The tool head fits a 5mm Allen wrench, but only just has enough left for me to make light adjustment. It needs a new nut so that I can properly adjust it again. I've got a couple photos of it here. Can anyone direct me to a replacement part?

It also needs some fretwork pretty bad, but that's a story for another day.
 
#2
The real important question is what the thread on the truss rod is, since the nut has to match the truss rod. It's very possibly metric. I looked around for a metric truss rod nut recently for a made-in-Korea acoustic guitar and couldn't find one.

So far, my idea is to get a metric threaded hex coupling nut and either cut slots in one end of it, or epoxy a metric socket cap screw into one end. Anyone else have any ideas on this?
 
#3
I just compared mine to one I found on ebay, since I have no way of measuring the threading. I'm almost certain it's an M6 thread with a 5mm head and a 25mm long cylinder. Ebay always delivers on those weird, hard to find parts.
 
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#6
harrumphicus said:
I just compared mine to one I found on ebay, since I have no way of measuring the threading. I'm almost certain it's an M6 thread with a 5mm head and a 25mm long cylinder. Ebay always delivers on those weird, hard to find parts.
Click to expand...

You can easily figure out what the threading is. Take the truss rod nut completely out, take it to the hardware store, and see what size bolt fits the threads.
 
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#7
Already tried, apparently my hardware stores are poopie and won't/can't help me figure out the threading. I've done this in the past when I lived elsewhere, but no luck.

edit: haha... I didn't say poopie. Sorry, autocensor!
 
#9
Lownote38 said:
They don't have drawers of metric bolts you can pick out to try? Even the Mom and Pop hardware stores where I am have that.
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I completely forgot. I think I intended to do that the first time I went in but they said they didn't have a way to measure it for me and it threw me off. I already ordered one I'm 90% sure will fit, the other dimensions match and the size looks the same. If not, turns out the store I bought it from on ebay is in the same city my band practices in so I could just take it in and get the proper one.
 
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#10
harrumphicus said:
I just compared mine to one I found on ebay, since I have no way of measuring the threading. I'm almost certain it's an M6 thread with a 5mm head and a 25mm long cylinder. Ebay always delivers on those weird, hard to find parts.
Click to expand...

Nice, apparently I never looked for these on ebay.

You should be able to figure out the threading by trying various bolts in there (and your hardware store should have known that). There are only a small number of standard bolt threads. A metric thread of that size is probably M6x1mm or M5x0.8mm. Tip: M5x0.8mm is very close to a SAE 10-32 thread, but this is a "Class B fit." I would avoid it for a truss rod unless there were no alternatives.
 
#11
reddesert said:
Nice, apparently I never looked for these on ebay.

You should be able to figure out the threading by trying various bolts in there (and your hardware store should have known that). There are only a small number of standard bolt threads. A metric thread of that size is probably M6x1mm or M5x0.8mm. Tip: M5x0.8mm is very close to a SAE 10-32 thread, but this is a "Class B fit." I would avoid it for a truss rod unless there were no alternatives.
Click to expand...
It's definitely not the M5x0.8mm then. I already have a nut that's a 10-32 and it's too small. This gives me hope that I bought the right one.
 
#12
Just got my nut in the mail and installed it. The M6 thread fit perfectly, for any future searchers looking for a replacement for a Japanese Memphis P-bass. Only took two adjustments to get it down to spec, .012" in stead of the maximum .023" I could reach before.
 
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