Replacing the truss rods?

[johnallg]

A question - could an old 4001 rod system be replaced with long single rods like the new ones are that goes through a plate at the body end (and be nutted there) and then a typical top plate/truss nut at the headstock end? Or are the channels too large to do that?

[chefothefuture]

To do that you would need to remove the finger board and then
install wedges on either end of the neck to create a channel that
is lower in the mid point of the neck. Then you would have to
create a filler that would be glued in and held in place by the finger board.

Better to make new rods using a better material.
Pinch rolling roundstock weakens the metal as it
molecularly distorts the structure; use a file to shape.

Not to be the doodoo in the pool,but I don't care for the new rods
for the reason of how they anchor....

Dale and I have had long conversations about this...
And we are in agreement.

[jingle_jangle]

You would also have to counterbore the body end of the neck undersize to the hex SEMS jam nut and cap nut, in order to seat these and allow them to lock in place at the body end.

Whether the truss rod is the old type of folded flat wire or the new type of straight mild steel rod stock, the only way that it's possible to break one is by applying unnatural amounts of torque on the adjusting nut. With the old rods, not pre-stressing the neck and expecting the rods to move the neck by themselves, often results in the person doing the adjusting to crank down on the nuts with an inappropriate tool (ratchet, breaker bar, crossbar nutdriver) in order to effect immediate visible results.

With the new type of rods, it's usually a combination of wrong tool and impatience.

In either event, whether the flat rods are ground or rolled to shape (filing would take a century and would be a good chore for a Rick enthusiast with a long prison sentence...), the amount of force generated in normal use is such that the method of creating the flat is irrelevant. If greater tensile strength was needed, an allot of higher specification could be used, or, simpler yet, the threads for the adjustment nut could be rolled, not die-cut.

As it is now, the weakest places in the old rods are at the fold and at the transition from threaded to unthreaded area. The new rods have two of these threaded to unthreaded transitions: one at each end.

[rickfan60]

As it is now, the weakest places in the old rods are at the fold and at the transition from threaded to unthreaded area. The new rods have two of these threaded to unthreaded transitions: one at each end.

Yep, in my experience that is exactly where they break.

[silverjet89]

I'm actually wondering now if maybe my channel IS too deep. My rods slide in and out faily easily and I do seem to have to have them really cranked down to get the neck straight. I can still only get it to a relief of about .004 which isn't too bad. I'm using D'Addario XL170s. Extra tape might help but I can see it putting too much space between the bars so the nut plate would not contact the tapered rod end correctly.
Any other suggestions? Paul?

[rickfan60]

I'm actually wondering now if maybe my channel IS too deep. My rods slide in and out faily easily and I do seem to have to have them really cranked down to get the neck straight. I can still only get it to a relief of about .004 which isn't too bad. I'm using D'Addario XL170s. Extra tape might help but I can see it putting too much space between the bars so the nut plate would not contact the tapered rod end correctly.
Any other suggestions? Paul?

That is good relief so it might not be the neck itself. Have you had your frets leveled? Older Rick frets are not a picture of precision and could easily account for that. The rods should be snug but not wedged in there. You should be able to move them by hand fairly easily.

[jingle_jangle]

Doesn't sound, by your description, that they are too loose. And .004" relief on a Rick bass might a well be dead flat. You're OK, IMO.

[gshadoan]

The factory rods that were in my 4004 5er, Dale and I found were fouled. We broke one of them straight away. The new rods however that he made for me, are very functional. In fact i just got done adjusting for a heavier guage strings i installed. Dead straight. Started out with a nice curve in the neck.

Also, I would have to think, that rolled rather than ground would have a better uniform strength and duriblity. That is since metal in general gets stronger when pinched, rolled, beat, heated/cooled etc.. rather than grinding AWAY material.
I might be wrong, but I did watch a discovery channel show on steel. But I didn't stay at a holiday inn express last night so I might be all wet on the subjet

[rickfan60]

Sometimes the masking tape on the new style rods gets bunched up or tears when the rods are inserted. This will gum up the rods and make them less positive. In the worst cases, the person doing the neck adjustment may tend to over tighten - easy to do. If the nuts bottom out they can snap the rods right near the nut. I have fixed a few like that. When I re-install rods I put a little carnuba on them first so the slide in smoothly without tearing the tape. I used to use hand soap but I think it caused the rods to rust a little.

[silverjet89]

That is good relief so it might not be the neck itself. Have you had your frets leveled? Older Rick frets are not a picture of precision and could easily account for that. The rods should be snug but not wedged in there. You should be able to move them by hand fairly easily.

Brand new frets as a matter of fact. Neck straight as an arrow without strings on or truss rods in. No problems there. The rods are snug but can be pulled out by hand fairly easily so it sounds like I'm OK there.

It just seems like I have to really crank the rods to get it straight. I always feel like I'm going to strip the threads. I can barely turn them with the nut driver. My adjustment procedure is to clamp the body to my workbench, push the neck back to the point where the strings just touch the frets, adjust the nuts, then slowly release the neck back. If I just pull the neck back a little I can't adjust it.
I cut and re-threaded the rod ends during the restoration but maybe they still have a problem.

I finished restoring this bass about a month ago and have hade to adjust the neck once or twice a week to keep it straight. It still doesn't seem stable. I checked the relief yesterday and it had gone from .004 to .008 so I gave the rods another slight turn.