Truss rod doesn't seem to be working in my Univox 335 Copy

[Rota]

I was given a Univox 335 copy bass last summer by my cousin and have been planning on getting it all working again. I finally sat down and fixed most of the electrical problems and it actually sounds really nice.

For some reason the action has always been extremely high no matter what I did with the bridge, and I finally realized that the neck is really bowed. Not a big deal I thought, and I gave the truss rod a half turn clockwise and let it sit for a day or so. Nothing happened on the bass so I gave it another half turn about two days after originally adjusting it. It still doesn't seem like it has moved.

Is there anything I can do, or should I just assume that the neck is shot and give up on it? I love this bass and I really want to make it playable again, but the action is just completely unplayable past the 5th fret.

I'd really appreciate any help I can get.

[Jimbob Jones]

Loosen the strings (but don't remove them) and the truss rod completely, then, while the bass is on a table on its back, get a friend to lean on the body. Push the neck out of its bow into just past the desired position (to allow for string tension) then tighten the truss rod. This should help a lot. This way you are only asking the rod to hold the neck straight, not to actually pull it out of the bow.

Another thing that will improve the truss rod's operation is to remove the nut completely, clean it, and put a good coating of vaseline on the thread inside and on the bearing surface. This makes it work a lot more smoothly.

[202dy]

If a neck has taken a set over a long period of time merely removing the strings to allow a neck to relax will do nothing to alleviate the problem. The neck has taken a set. Much like a bent wood rocking chair the wood will retain the new shape until an outside force is used to act upon it and change it's shape. Most often this can be accomplished handily with a clamping rig and the truss rod. When a neck has taken a set and the truss rod is not effective at holding an adjustment, it is standard practice in most repair shops to place a neck into an artificial back bow before adjusting the truss rod. Typically the neck is stressed by using blocks at F1 and the neck body joint, a beam on the block, and a clamp and caul at F7. The strings are typically left on but taken slack and moved off the nut and to the sides of the neck so as to not interfere with the blocks. In some cases if the neck is resistant to change it will take as many as six attempts over the course of an afternoon to get the truss rod to hold.

Occasionally heat must be applied but this is only necessary when nothing else works.

[Rota]

Thanks guys. If I took the bass down to a shop, what do you think they'd charge me to straighten the neck?

[202dy]

Originally Posted by Rota

Thanks guys. If I took the bass down to a shop, what do you think they'd charge me to straighten the neck?

Depends. The charge should be in addition to normal setup charges. Figure the charge to be at least $25.00 USD and could run as high as $50.00. Heat treatment will be more. It all depends on how responsive the neck is to the adjustments which translates into how much time the guitar is on the bench.

[Pilgrim]

I have a Univox 335-copy as well and they're great period basses. Take good care of that one! The body and wood work on those are top-notch, built in the Matsumoku factory.

Here's mine:


I'd say that if you have a shop competent to do the work outlined by 202dy it would be well worth it to spend the money. I really hope it works out for you. That neck is a bolt-on, so it can be removed.

I'd be just a little careful about the advice above regarding an adjustment involving having a friend "lean on the body". That makes me a bit nervous with a hollowbody bass but I understand the idea is to be able to reach the truss rod nut while pre-loading the neck into the desired position and then tightening the truss rod. Just make sure that your assistant don't apply enough force to damage the body. Removing the neck is pretty easy (watch for any shims that might be in there so you can replace them in the proper position) if you need to - that's probably how a shop would proceed.

You can pre-load the neck by