Truss Rod Nut?

[D Bopp]

I read a few posts about putting a washer on the truss rod nut if the TR is maxed out. How does this help in adjusting the truss rod? How can you crank the rod more if it is already maxed? Sorry. I'm just not grasping the concept.

[pbagley]

If the nut has reached the end of the threaded portion of the rod, then the washer moves the nut an additional 1mm (or what ever the washer thickness is) away from the end of the threads, allowing an additional turn or so for adjusting before it bottoms out again.

- Paul

[202dy]

The truss rod is a smooth threaded rod as opposed to a piece of all thread, which is threaded along the entire length. When people refer to the truss rod nut as being "maxed out" what they mean is that the nut is tightened to the end of the threads. It is bottomed out. This is caused by the force of the nut crushing the wood fibers at the nut end of the neck at the bearing edge, thereby exposing (in many cases) the unthreaded portion of the rod. Placing a washer or two on the rod and rethreading the nut on gives the nut threads to turn on because it effectively compensates for the increased length of the access hole due to the crushed wood.

[60bass]

Originally Posted by pbagley

If the nut has reached the end of the threaded portion of the rod, then the washer moves the nut an additional 1mm (or what ever the washer thickness is) away from the end of the threads, allowing an additional turn or so for adjusting before it bottoms out again.

- Paul

100 % correct.

However be advised that if your truss rod is already maxed out and you still have excessive bow, you probably have other neck issues causing that rod nut to max out.

You could remove the neck, remove the rod nut, and clamp the neck into a backbow condition and then add the washers and nut back on while still clamped.

Then snug up the rod nut, and remove the clamps. If everything goes right, and the neck doesn't flake out or the rod doesn't snap, you should be able to string it back up.

The guitar will probably buzz dead down low because you put the neck into a backbow condition. Slowly loosen the rod nut (with the strings loose) to bring the neck back into proper relief. Then do a full setup and hope for the best.

I've done it many times but for me at least it only works about 50 percent of the time.

Keep Low

[bobunit]

Originally Posted by 202dy

The truss rod is a smooth threaded rod as opposed to a piece of all thread, which is threaded along the entire length. When people refer to the truss rod nut as being "maxed out" what they mean is that the nut is tightened to the end of the threads. It is bottomed out. This is caused by the force of the nut crushing the wood fibers at the nut end of the neck at the bearing edge, thereby exposing (in many cases) the unthreaded portion of the rod. Placing a washer or two on the rod and rethreading the nut on gives the nut threads to turn on because it effectively compensates for the increased length of the access hole due to the crushed wood.

+1 and these might work for the application... http://www.stewmac.com

[D Bopp]

Thanks for the info. This bass is what I am referring to. It's a 64 Jazz. The neck feels good, but the rod won't turn any more. I'm just thinking about if it starts to bow more in the future.

[62bass]

Good idea to remove the neck and clamp it into a slight backbow before adding the washers. It'll remove the stress and make adjustment later easier. You could need 2 or 3 washers for enough total thickness.

You'll for sure have to do a bit of fiddling with setup once you get the neck bak on, but this fix will work if the problem is simply because the nut ran out of adjustment room. It is a common problem with many Fenders I've seen.