'75 4001FL - truss rod troubles

endlessbassic · Post by **endlessbassic** » Thu Jul 21, 2005 2:31 pm

Hey Everybody.. thanks for the replies. I have, however, seen most of the info/pages/projects listed above, though i do appreciate the help! I've really tried to do my best to exhaustively research everything, so i don't waste any of your respective time(s).

I now think i may have a source for the rods and/or nuts (waiting on a call back), but here's the problem: as i said before, the rods will slide to the end of the the cavity, but to be able to fully remove them, i'll have to exert enough upward pressure to clear over 1/4" to get the threaded end out, and i feel strongly, given the scant amount of t-rod length sitting in the cavity, that this could easily pop the fingerboard.. i learned long ago that physics is, to me at least, a fair-weather friend! Maybe i'm being paranoid, but better to be safe than sorry, right?

I'm still not opposed to pulling the exisiting rods, and 'reconditioning' them, but maybe in the long run, new rods are
the way to go? I gotta get this baby back up and running.. i'm losing my touch over here!

So, again, sorry for the long reply.. all in the interest of clarity..
Hope you all are having a good evening..

wints · Post by **wints** » Thu Jul 21, 2005 2:54 pm

When you finally get out of this mess Cale, make sure you fit some fairly low tension strings, be they round or flats.
It sounds the cause of this was probably a set of Fender flats or similar of very high tension.

jps · Post by **jps** » Thu Jul 21, 2005 3:44 pm

To remove the rods you must first clamp the fingerboard and neck right behind the nut to prevent the POP!

endlessbassic · Post by **endlessbassic** » Fri Jul 22, 2005 4:24 am

Good call, Andrew.. i had a medium set of Chromes on 'er for about 1 1/2 years (and frankly, i should have left well enough alone!), but the adjustment debacle started when i put that new bridge and some medium SIT Silencers on, which i thought were pretty low tension. Regardless, i think you're onto something here.. i'll look into it further. thanks!

Re: the clamp.. also some excellent advice. Thanks, Jeff! ..only one clamp needed, though? I've never seen a pic of f-board 'pop', but i would imagine it happens in that general first fret vicinity.. And are the new rods relatively straightforward to install? In other words, 'out with the old, in with the new', without any special tricks?

ken_j · Post by **ken_j** » Fri Jul 22, 2005 5:26 am

They are not interchangeable. You can shorten the old rods to get good metal to work with. JH commented on this in a post a few months ago.

endlessbassic · Post by **endlessbassic** » Fri Jul 22, 2005 5:47 am

Ken, can you please clarify what 'they' means in this case? I don't want assume you mean 4001/4003 rods, as i understand they're completely different animals.. thanks.

johnhall · Post by **johnhall** » Fri Jul 22, 2005 6:23 am

Cale, you asked about 4001 truss rods, Ken just told you about 4001 truss rods.

endlessbassic · Post by **endlessbassic** » Fri Jul 22, 2005 6:57 am

Hi John.. my confusion stems from the word 'interchangable' as Ken used it (was this in response to q#2 re: 't-rod nuts'?), as initially i was asking about the notion of repairing/replacing rods for a 4001 specifically. It's entirely possible that i'm missing the point, though i do recognize that shortening the rods will accomplish my goal. I do apologize if the obvious has escaped me.. thanks much.

ken_j · Post by **ken_j** » Fri Jul 22, 2005 11:30 am

What I mean is that the "new style" rods are not interchangeable with the "old style" rods. The old style rods are no longer available from RIC as far as I know. I would try and repair what you have. If you have the proper tooling you could fabricate new ones. It has been a while since I have pulled any out but if I recall correctly the rods were made from an odd size of metal stock. They were sort of oval shaped looking at the ends. This would allow them not to be as thick from front to back (of the neck).

jps · Post by **jps** » Fri Jul 22, 2005 3:29 pm

AFA clamping, you just need to clamp the neck front to back to ensure that the fingerboard will not pop off when exerting the pressure while pulling the rods out of the channels. Stew-Mac makes a nylon clamp that wraps around the neck that may work; I have not tried one of those. I just used a standard C clamp with padding to protect the finish on the FB and back of the neck.

endlessbassic · Post by **endlessbassic** » Fri Jul 22, 2005 3:35 pm

Thanks for the reply, Ken. You are correct about the stock being somewhat oval, and i don't have it in me to source the steel at the moment. At this point, i am going to attempt to remove the rods, cut about 3/8" (the apx. amount of damaged thread) off, as well as a comeasurate amount from the beveled (upper) end and recut the threads (does anyone know what thread gauge they are?).

While we're on the subject of cutting, how much is too much? Am i correct in thinking the rods only travel to the 12th fret mark? Will this ultimately pose a problem with the 'final' adjustment? So many questions for only two thin pieces of steel..

endlessbassic · Post by **endlessbassic** » Fri Jul 22, 2005 3:48 pm

Thanks, Jeffery.. i was going to try to make a 'jig' or 'frame' for the c-clamp (to more evenly distribute the pressure) that is the approximate radius of the fingerboard (as well as the back of the neck) to avoid damage. I'll pad the inside of that, should all go well.. This is good; i now feel like i can at least move a little bit forward! I really appreciate everyone's input!

jps · Post by **jps** » Fri Jul 22, 2005 3:53 pm

I was a bit nervous the first time (weren't we all?), but it turned out to be rather easy and dare I say, enjoyable!

rictified · Post by **rictified** » Sat Jul 23, 2005 8:37 am

I have pulled plenty of 4001 rods out of basses and have never popped a fretboard, it is unnecessary to clamp the fretboard IMO, you just need to use a pair of needle nose pliers to get the threaded part beyond the end of the cavity so you don't scratch it, it will then pull out easily with a little tugging as they are curved. You can turn the nuts around and the other ends should be square. If they need to be rethreaded I recommend going to a good machinest who can cut off the threaded ends and weld hard steel for just the threaded ends, you will then have no more problems with the aluminum block tipping, the reason they tip is that the steel rods are too soft and bend under the pressure from the other end of the folded rod which pushes against the back side of the block opposite the nut end pushing the block over. (that is where all the tension is, they pop because when they tip the rods up in the cavity right under the nut and push the fretboard off or split the neck, this was the main problem with the 4001 truss rod system, the steel was too soft where it went through the block and bent too easily)
I've had two done, on one the guy cut off the old ends and used the existing steel and rethreaded the rods, it still tips, and the other was done the way I descibed above and I have had absolutely no problem with tipping or fretboard popping and I've used some pretty heavy duty strings on it at times.
My quick and dirty way of adjusting 4001 rods is to stand up the bass on a rug, put my right foot behind the bottom of the bass, my right knee behind the mid section of the bass and pull back on the neck with my left hand to relieve the pressure, this way you can do it yourself and also sight down the neck and adjust as needed, I can do a bass in about 5 minutes including taking the TRC off and putting it back on if it only needs a little tweak. (I have obviously already taken off the TRC and have a 1/4" nut driver in my right hand before I stand it up and flex the neck backwards) It's not rocket science, you just need a little common sense. there's nothing mysterious about them and unless you have a major problem which only a good luthier can fix it is much better to learn this simple method yourself. If you need to pry the nuts up to get a nutdriver on them to loosen them I would then recommend using a clamp near the nut area with protection so you don't dent the wood, or alternately you can use needle nose pliers to slowly turn them off, this is a PIA but you don't need a clamp. You can easily cut off an inch per JH and have no problems at all.

charlyg · Post by **charlyg** » Sat Jul 23, 2005 9:32 am

This is maybe too basic, but the neck should have a slight bow(slightly lower in the middle sighting down the fretboard). It should not be straight. This is from a couple of luthiers I know.