The Truss Rod Wrench Mod

So at the time of writing, literally* ALL THE GUITARS are in my workshop for a refret. This means that this week’s post will, necessarily, be a quickie. Hope that’s ok.

A simple modification to your allen/hex wrench can prevent damage to pickguard and finish

Adjusting Truss Rods at the Neck Heel

The Fender-style necks with a truss rod that adjusts at the heel can be a challenge to adjust.

In most cases, it’s necessary to take off the neck to gain access to the adjustment. This means you need to slacken off the strings, adjust the truss rod, tune back to pitch, and check the relief. If the truss rod gods have smiled on you, relief will be exactly where you want it. More likely, you’ll have to repeat this process a number of times, getting more and more furious every time.

There are a couple of rays of dim light, shining through the murky clouds of body-end truss rods, though…

The Lucky Telecaster

We’ve talked about this before but it makes sense to reiterate it while on the subject. Sometimes, on a Telecaster, you can remove the pickguard and get access to the end of the rod via a short channel in the body. Yay!

If you are this lucky, you’ll probably want to invest in a right-angle screwdriver like this one from Stew Mac. Otherwise, the pickup tends to get in the way.

 If you're lucky, you'll be able to remove your Tele pickguard and adjust the truss rod underneath

If you're lucky, you'll be able to remove your Tele pickguard and adjust the truss rod underneath

Of course, many Telecasters have no access channel. And some, you can’t easily remove the pickguard on. Oh, well. Back to unscrewing the neck.

The Lucky Bass

Some Fender basses will have an small slot cut in the body and the pickguard to provide some access to the truss rod adjustment.

The problem is, the damn slot is usually too short.

When you stick a hex/allen wrench in to the truss rod, even a ball-end wrench (which you have to use here — don’t try a regular hex wrench) won’t let you get a reasonable angle.

 Grrr. Stubby little access slot makes truss rod adjustment difficult and risks marring pickguard.

Grrr. Stubby little access slot makes truss rod adjustment difficult and risks marring pickguard.

If you try adjusting the nut, you end up with the wrench corners digging into the pickguard and scraping, chipping, and marring it.

Bad design.

So, to workaround, you can modify your hex wrench.

If you file off the corners close to the ball-end, you can make a ‘safe’ area that’s ok to contact the pickguard.

 File the corners off the shaft of a ball-end hex wrench to avoid scratching the pickguard

File the corners off the shaft of a ball-end hex wrench to avoid scratching the pickguard

Because it’s a ball-end wrench, the area to be filed doesn’t really do anything so you’re not really impacting the wrench’s usefulness for any other jobs.

This is a useful mod if you’ve got an instrument with a stubby little truss rod access channel.

 Now you can safely adjust your Fender bass truss rod. Yay.

Now you can safely adjust your Fender bass truss rod. Yay.

That’s it

That’s your lot. I’m off to continue hammering fret wire.

Off you go and modify your hex wrench.