4001 Truss Rod Help

[deblase4001]

I could not get the neck flat enough on my 75 4001. The TR ends were bent down and digging into the wood and the spacer was mangled up. I carefully got the nuts and spacer off. I made a new spacer, installed and readjusted but no luck. Still too much relief in the neck. I pulled the rods out today. They came out easily. The ends are bent downward and the rods are completely straight. So should I try to straighten the rod ends, bend and arc in the rods and then reinstall. The neck is not totally flat with the truss rods out. I will let it sit for a day or 2 and see if that changes at all. Thanks for any advice. I really want to get this bass playable again as it's my main gigging bass.

[rickenbrother]

Put the nuts on the threads and try to carefully straighten out the threaded end with a pair of pliers. If this does not work out for you, the truss rods are longer than they really need to be. You can cut the existing threaded ends and tap new threads at the start of the ends that you've cut. Cut the non threaded other half accordingly on the same (headstock) side.
Before reinserting the rods, bend them so the apex of the arc will be towards the fingerboard, like a frown going into the neck.
Maybe this thread in Fretless Basses Forum will help you:

Got Rid of A Rattle

[BAD RONBO, KiLLeR DWaRfS]

love them early '75's with 1/2 " spacing ! someday...i will own one.

[gareth]

What Joey said. I'd go with bending them and chasing the threads with a die before cutting. They don't look that bad in the photo.

I really have to do this on my 79 4001. For future reference, you can do this in situ if you clamp the finger board down and proceed very gently....

[T.A.R.]

I went through the process with my '74. Joey's Bass notes and the advice and support of the RRF were invaluable, I wouldn't have been able to without them. By the way She is now dead flat and plays great!

[cheyenne]

+1 to all the above. I might add that when your done with the rods, make sure you adjust them using the older 4001 method.(manually setting the neck straight, then tightening the rods).

[Kopfjaeger]

Ok, get ready for a potentially stupid question. I was under the impression the rods came out of the neck via the neck base, near the pick guard. Is that correct? The OP foto shows what looks like the pick guard in place and buttoned up. Am I wrong in my initial understanding?? Will they come out via the TRC cavity??

Sepp

[cheyenne]

When the 4003 came out, the rods were installed from the body end. That why the early 4003's have the 2 piece pickguard.

Correct guys?

[cjj]

When the 4003 came out, the rods were installed from the body end. That why the early 4003's have the 2 piece pickguard.

Correct guys?

Yes, but only on early 4003 basses. The 4001 had the "folded" truss rods as shown above, these could only be taken out at the headstock end. The early 4003 models with the 2 piece pickguard has this type truss rods, but reversed and came out at the body end. As you can see from these pics of my '84, it would be pretty hard to take 'em out of the headstock since you can even see 'em there.

Later on, the truss rods changed to the new single rod style that has the adjustment at the headstock and an "acorn" nut at the body end. I don't know if any of the late 4001 basses ever got the new rods (well, except for the 4001 "reissues" such as the 4001V63 which are made like a 4003).

[antonius]

Greg,

The rods on my May 1975 4001 were once in exactly the same state as yours. I didn't need to cut the ends off and rethread. As suggested earlier I took the rods out, put the nuts on and very carefully and slowly manually bent the ends back straight. I then put a drop of oil on the threads and run the nuts up and down the threads until I could eventually screw them on with finger strength only. The nut kind of recut any rough patches of the thread. You don't want any resistance or friction preventing the nuts being tightenened when installed. I also cleaned up the rods and filed the slope of the unthreaded end so that there were no rough edges.

I then bent a curve in the rods so that when I placed the ends of the rods on the desk the apex/middle was about 2 to 2.5 inches above the desk. They were actually quite easy to put back in the slots despite the curve in them but I would strongly advise clamping the end of the fretboard securely because the bent rods may exert an upwards force on it as you push them in and you don't want to pop it off. The goods news is that with the arc in the rods they have MUCH more strength in them so I don't have to tighten them so much and so there is less tendency for the ends to bend down into the cavity again.

Good luck!

[grygrx]

I find almost everything about doing work on this type absolutely frightening. Best of luck!

[deblase4001]

Thanks everyone for the help. I definitely have been using Joey's site and the wealth of info that is here. Looks like after sitting overnight the neck now is nearly flat without any tension on it. So hopefully straightening the rod ends and arcing them will do the trick.

[Kopfjaeger]

Thanks for the clarification. i was aware the 4003/ newer style truss rods had an acorn nut on the pick guard end. The 4001 rods, I had never seen one out so I had no idea what sort of animal it was. So by the looks of it, it is one rod folded over with one end section threaded? Is the other folded end welded to the other?? In the foto, it looks like one is attached and other is not I'm guessing not since tightening the nut pushes on the folded end which causes it to bow? Is that correctish?? Kinda like an archers bow with the threaded rod being like the string and "bent" rod acting like the bow??

This is much less "scarey" for me if I can understand the principle of how the folded rod keeps the neck straight.

So which years and models had issues with the collapsing/compressing wood in the truss rod channels? I was under the impression it was early 70's 4001's but with no upwards tension (toward the headstock) with the 4001, I'm now guessing that was not an issue with 4001 basses??

Sorry if I'm stomping on the OP but this is a huge clarification of something I obviously may have misunderstood.

Sepp

[cjj]

The "folded" rods are just that, a long piece of metal that's bent in two. They are connected at the bend, but not at the "business" end, where the nut goes. Tightening the nut pulls the rod end against the aluminum plate causing the rods to bow/spread. This is why, if you just torque the nut, you can split the fretboard off of the neck like this (my '76 4001 - done before I got it, but repaired and works just fine):

The rods are meant to provide pressure to hold the neck in position, not to move the neck. So, that's why you manually push it into position and THEN tighten the rods to hold it there...

[rickenbrother]

I like the old style rods, I think they work well. The problem was many did not adjust them properly as CJ explains in his post. Improperly adjusting the old style rods can result in damage to the neck and/or the rods.