Fender Bass Repair : 1969 Fender Precision Bass Truss-Rod Repair

On the workbench is a 1969 Fender Precision Bass with a problematic playing action. The action is high and the bass is very uncomfortable to play.

It was bought through a popular online auction and was brought into the workshop for an assessment after the new owner had tried various adjustments but failed to make the bass more playable.

It had spent most of its life in its case inside a closet. This is confirmed by its amazing condition. The finish is bright and clean with very little markings or lacquer cracks. The hardware is all original and unusually the bridge and pickup covers are still present. I suspect that it was put away and forgotten about because it is such an effort to play. This would account for its immaculate condition.

Click image to enlarge

Fender Truss-Rod

On all early Fender guitars the truss-rod adjuster is at the body end of the neck. Upon inspection it is apparent that the truss-rod is not working as well as it should. Any adjustment has little effect on the neck.

Upon testing the truss-rod, it appears that the adjusting screw reaches its limit before any changes to the neck are effective.

The prognosis is that the truss-rod is either broken internally or that the adjusting nut is ineffectual in some way.

The remedy is to replace the truss-rod.

This is a problematic job as this would require the rod to be removed without removing the fingerboard. It is not possible to remove a Fender style fingerboard without changing the nature of the neck beyond all recognition. This would detract for its originality and drastically devalue the guitar.

A Fender truss-rod is made from a piece of round section steel with a “T” soldered onto one end (the truss-rod fixed point )and a thread tapped onto the other end to accept the adjusting nut. Once fitted into place, and when the nut is tightened, the adjusting nut pushes against a fixed internal washer which is part of the inner channelling that the truss-rod sits into.

It is decided to create an opening in the fingerboard directly above the truss-rod fixed point and expose the “T”.  Once exposed, the “T” can be severed and the rod extracted via the body end on the neck.

A magnet stack is used to locate the end of the truss-rod

A section of fingerboard is scribed through and removed thus revealing the “T” fixed point

The “T” is drilled through and severed

The rod is extracted through the body end of the neck

Testing the truss-rod once it has been removed, it is apparent that the adjuster is ineffectual. As the adjuster is tightened it has the effect of ejecting the screwdriver (very frustrating).

Click image to enlarge

A new rod is made up using a piece of silver steel and a different style of adjuster. This is inserted into the headstock end of the neck and fixed. Silver steel is a tougher material and more likely to allow for extra torque that may be needed on final adjustment.

The fingerboard piece is replaced

The area smoothed over and cleaned up

Frets 1 & 2 are replaced and a new bone nut made and fitted.

The Conclusion

I am pleased to report that the truss-rod works well and has made a vast improvement to the basses playability. The initial cost of a repair such as this is easily justified due to the overall value now put on this fully functional  ’69 Fender Precision bass – all original and in excellent condition – in short a splendid bass.

The bass is now permanently out of the closet and enjoying its new lease of life by its new owner.

More on P. Basses here

Broken Truss-rod: Gibson Les Paul Custom Shop

This Gibson Les Paul Custom Shop ’68 F series was in serious trouble when its truss-rod snapped off at the end.

Gibson Les Paul '68 Custom F


It is owned by a guitarist who just couldn’t “get on with it” because of its high action. It was put away and forgotten about. Several years later an acquaintance and Les Paul enthusiast offered to buy it. But firstly, before any deal was struck, the potential new owner wanted to lower the action and make the guitar more playable. On tightening the truss-rod disaster struck, the rod snapped at the top!

This photograph shows a straight edge against the frets around the 7th and 8th fret area of the fingerboard. This reveals a very high action; because of this high action adjustments to the truss rod were attempted.


Without a working truss-rod this guitar was destined for the scrapheap because the guitar could never be adjusted for optimum playability.

The next sequence of photographs shows how a broken truss-rod problem can be resolved.



Nut and washer removed


Specialised boring tool for removing material around the truss-rod


Specialised tool for extending the screw-thread further down the truss-rod


Load-bearing washer is fitted into place


A new adjusting nut is attached and the truss-rod adjusted


The repaired truss-rod end


The straight-edge now shows a truss-rod that is working


Truss-rod adjustment is a fairly rudimentary and simple alteration to make, but could end in disaster!

If your truss-rod feels stiff or locked in place there is a danger of it breaking if over tightened.

If in doubt seek professional help.

More about truss-rod adjustment here…

Bass Guitar Repairs London: Vintage Washburn B-20 Bass

One of my regular customers, and a collector of rare and unusual bass guitars, bought this Vintage Washburn B-20 bass into the workshop. He had hoped that it might be resurrected.

The immediate problems were:
•    Heavy fret wear
•    The electrics were in disarray with parts broken and missing
•    Machine heads missing
•    Nut missing
•    The Finish was scratched and battered

All in all it was a mess, after a workbench examination it became clear that most of the jobs were doable but there was one nagging problem, there was an extreme split to the back of the neck.

A major worry as this meant that this guitar was destined for the scrap-heap if this couldn’t be resolved. It appeared that the truss-rod was trying to burst out through the back of the neck.

This truss-rod problem could have been due to: (1) Faulty manufacture or material (2) A sudden shock to the back of the neck (3) A fault with the playing action that necessitated the truss-rod being tighten beyond its limit. Whatever the reason I needed to investigate further.

After a quick test I discovered that the adjuster was locked as tight as possible but the neck was in an upward bow. It was the  truss rod type that adjusted with an allen key and it showed signs of heavy use.
Another test would have been to string the guitar up, slowly bring the strings up to concert pitch and to check how the neck responded, but that was not possible as two of the machine heads and the nut were missing.

I decided to make an extreme adjustment test to the neck and truss-rod.

Using a heavy-duty straight-edge, blocks of wood placed at either end of the neck and a clamp at the centre of the straight-edge, the neck was gently forced back into a back bow. This took the strain off of the truss rod and held the neck in a back bow. With the truss rod under no pressure from the neck I was able to tighten the adjuster further to hold the neck in a back bow with the truss-rod. The splits seemed no worse for this action.
With the neck now held in a new profile, correct adjustment was guaranteed when it came to setting up the guitar. The tension could be slowly released, at the adjuster, until the optimum position was reached.  But first the cracking and splitting to the back of the neck would need to be remedied

The finish around the Mahogany insert was scraped back and the cracked insert routed out. This left a straight and clean channel for the replacement. This was to be a piece of ebony because of its strength and density (taking no chances here).

From left to right:

1. Neck held in jig

2. First router pass shows how deep cracks go

3. Third pass reveals truss-rod

4. Ebony inset glued in place

5. Cutting back the insert

As well as the neck repair here is a list of jobs that were carried out to bring this old War-Horse up to playing spec.

A Partial Re-fret

The frets showed signs of heavy wear and tear on the first 9 frets. These were replaced with identical fret wire. All frets were honed, re-profiled and polished

The Electrics

The pickups were working but the electrics were in a mess, components missing, bad solder joints and the components that were present were cheap and nasty. All pots, caps, 3-way toggle, jack socket and wiring were replaced and the pickups were giving a complete overhaul.

Machine Heads
New machine heads were sourced and bought in.

The Nut
A new nut was cut from a bone blank. How?…

The Finish
The Finish probably seemed worse than it actually was. The guitar’s top and back had what seemed like lines scratched into its surface. On closer inspection these weren’t scratches at all but gold pen and would probably polish out. Was someone, somewhere really considering cutting along these dotted lines?! There were many scratches and knocks all over its body. Although many of these would never polish out the owner resign himself to the guitar showing its “battle scars” and thought that it would probably look quite cool once the pen marks were removed and the finish polished up.

The Final Job

The last job was on the electrics back cover. This had curled up like a stale sandwich and would never go back into place without some attention.
I used my rib bending-iron and applied a little moisture and heat.

The Finished Result

Guild 302A Bass Guitar Broken Neck Repair

The Guild 302A , a unique vintage bass.

This Guild 302A bass was brought  into the workshop with a split in it’s headstock. This presented a fairly routine repair. It was to be a visible fix because of budgetary constraints.

During the course of the repair it was decided that the existing Badass bridge should be removed and an original BT-4 bridge be installed. The chances of finding a BT-4 were fairly remote and the original for this bass had been lost several years ago. However, with much internet searching and to the great surprise and delight of the owner a second hand BT-4 was located for sale in the U.S.

On receipt of the new BT-4, the Badass bridge was removed and the old style bridge installed. The frets were polished and fingerboard cleaned. All the electrical components were overhauled and cleaned. The bass was fitted with new Rotosound strings, the truss rod adjusted and the string spacing and intonation set.

What resulted was a unique vintage guitar restored to it’s former glory.

Apparently only 500 of these basses were ever produced.

Spec for B-302A

Manufactured: 1978-81

Body: Ash

Neck: Set 3-piece maple, with 20 fret rosewood fingerboard

Scale: 34 inch

Overall length: 46 1/4″

Width at nut: 1 5/8″

Electronics/pickups: Two Guild single coil bass pickups, two volume and two tone controls, selector switch

Hardware: BT-4 bridge