Inside almost every modern guitar and bass neck is a truss rod: a long, adjustable steel rod that counteracts string tension on the neck. Without them, your guitar strings will eventually bend your instrument’s neck into an unplayable banana-shaped object. They’re usually pretty sturdy, but if abused, they can sometimes break. Our friend, Brandi Wynne from the band Ozric tentacles picked up this ’72 Fender Jazz bass neck with a broken truss rod and asked us to fix it. Here’s how we removed and replaced a broken truss rod.
This neck features a single-action truss rod installed in a channel in the back of the neck, which is then filled with a walnut “skunk” strip. So I had to remove that first to get to the bar itself. I generally use a heat gun to melt the glue – just need to keep it moving so I don’t burn the finish!
Once the glue bond was loosened, I drilled some tiny holes in the skunk strip, screwed a wood screw into the walnut, and used a special button-pulling tool to begin lifting the piece out of the neck. We often use tools designed for a specific task, for something beyond its intended purpose – sometimes the wrong tool for the job is the right tool for the job!
I used the button puller only until I could get under the streak of skunk with a 1/4″ chisel, then pulled out the rest with the chisel.
After the skunk strip was removed I was able to easily knock the tail out of the throat.
To replace the broken truss rod, I opted for a new one made from high-strength steel. I cut the new rod to length and then threaded each end with a die – one for the anchor, one for the adjustment nut.
The main reason I removed the Skunk stripe is that while the truss rod needs to be glued in, it still needs to be able to move freely in the neck. An insulator tube must be used to prevent glue from getting on the rod, but the tube itself is larger than the rod access holes at each end of the neck, so I placed the tube in the truss rod channel and then threaded the rod through it.
Then I glued the skunk strip back in place.
After removing the excess glue, I touched up the clear finish and buffed it back out to make sure it looked as similar as possible to how it came in the shop – battle scars and all!
Once the neck was reassembled, I bolted it to our replacement body and plected to align the frets and make sure it played clean with no dead spots.
As good as new! Thank you Brandy!
[A note from Benjamin: I experienced a weird bit of synchronicity when Aaron finished up this job, and I was preparing to ship it out. Ozric Tentacles had just put out a new record, which I put on right as I was making up Brandi’s invoice, not knowing that Brandi is IN Ozric Tentacles. I’ve been a fan of their music for over 20 years, and now they are sending their instruments to us to work on! Many miles away something crawls to the surface of a dark Scottish loch…]