Improving a Pacifica trem

robinbowes · November 2018

I have a Pacifica 012 that I picked up cheaply along with an Epiphone valve amp and Pod 2. I've sold the amp and Pod for more than I paid for the whole lot so the guitar doesn't owe me anything. I just keep it kicking around next to my desk to pick up when I feel the inspiration.

Stock pic for reference:

Image: https://images.reverb.com/image/upload/s--UolzTkyZ--/a_exif,c_limit,e_unsharp_mask:80,f_auto,fl_progressive,g_south,h_1600,q_80,w_1600/v1492613468/evkcgltiberyespiwmb4.jpg

I've done a few mods - Fender single coils - (I forget what type), a Gibson humbucker (see this thread), and a rolled steel trem block. The pickups are remarkably balanced, ie, the humbucker is not noticeably louder than the single coils.

The trem, however, does not work very well. It does not return to the same point every time and seems to be rather "sticky".

Here's a pic of the under side of the pivot point:

Image: https://lh3.googleusercontent.com/whOOr4HXdVM2HQfogGkwjlVF0YoJYNZjvy05HT414x5FhiRHd06Z37VYQM2S8Xwzmehh0kMv7LLoIn8cDkbfLukUnM90miHTGMsCKb0MHsYZpolryGIIzXYGwd6PxlIzLYUtriMUHW8=w689-h918-no

I bought a replacement (Strat) trem off here but stupidly didn't check measurements, and the Pacifica one is narrower.

This is the Strat trem - same angle:

Image: https://lh3.googleusercontent.com/ApM9W3uyCp80-KW0LqXvCxXKZPF1Zure30XGlhU-UKsTzwBl6X_aEQg-bagFPjCQkmK1ROuiW0XnooDeMeq0Wb1S1g-q4wnwZxg4xa5orp9Smz_DShQmqfsRdogelbrkXJqbUoMruqc=w689-h918-no

I notice that the Strat trem bevelled edge is different to the Pacifica.

Is there anything I can do to the Pacifica trem to improve things?

Any suggestions?

R.

sweepy · November 2018

Go get a Wilkinson Strat trem, it has oval holes so it’ll bit the Pacifica and has a push fit arm

robinbowes · November 2018

sweepy said:

Go get a Wilkinson Strat trem, it has oval holes so it’ll bit the Pacifica and has a push fit arm

Good suggestion, but the string spacing is also narrower on the Pacifica (53mm vs 56mm on the Strat). See pic:

Image: https://lh3.googleusercontent.com/dj2aHu7jSY7QZFVKtrLFpWlFl9Lsrpisq_mvxhBQHAWfIx9GmiIuU9fEfyVE57l6RGvKFmmnejpMJQZa3dSvG7CHwsKrN0Mq52XTmN_uWwYLkRFqg7jxla1gMKiSNw1JU8REXx5HmPc=w1530-h1147-no

I guess I could try one and see how much the extra width affects playability.

Unless they do a 53mm trem?

R.

Megii · November 2018

GFS do quite a few 10.5mm (52.5 mm total) spaced trems for upgrading, just in case of interest https://www.guitarfetish.com/Tremolos-And-Tremolo-Parts_c_203.html

Funkfingers · November 2018

sweepy said:

Go get a Wilkinson Strat trem, it has oval holes so it’ll bit the Pacifica and has a push fit arm

The Wilkinson vibrato you describe has five oval holes and one circular one. In order to align the replacement vibrato with the centre line of the guitar body, it may still be necessary to fill and redrill the hole for that outermost screw.

robinbowes said:

[The vibrato] does not return to the same point every time and seems to be rather "sticky". Is there anything I can do ... to improve things?

The bevel in the underside of the baseplate is not critical. The sharpness of the knife edges in the six pivot screw holes is.

The nut slots might benefit from some attention. If the material is plastic, it would be worth cutting an entirely new nut from a blank.

Finally, the tuners are not of the highest quality. They way in which the strings are wrapped about the posts can influence tuning stability.

The holes drilled through the headstock for the stock tuners are narrower than required for the majority of replacement hardware. It might work out easier to invest in a set of Gotoh Magnum locking tuners than to ream the Yamaha headstock.

ICBM · November 2018

It won’t be the bridge causing the tuning problems - that type of bridge works very well when set up right.

The critical points are the adjustment of the six pivot screws, the nut, and the way the strings are fitted to the machineheads. (Assuming there’s no major problem like the springs rubbing against the cavity wall.)

When it goes out of tune, does it stick in the same direction as the last arm movement, or the opposite? Is it all the strings, or just some of them?

robinbowes · November 2018

ICBM said:

It won’t be the bridge causing the tuning problems - that type of bridge works very well when set up right.

The critical points are the adjustment of the six pivot screws, the nut, and the way the strings are fitted to the machineheads. (Assuming there’s no major problem like the springs rubbing against the cavity wall.)

When it goes out of tune, does it stick in the same direction as the last arm movement, or the opposite? Is it all the strings, or just some of them?

It seems to stick in two positions, depending on whether it's pulled up or pushed down.

I'll try re-stringing it and see if Ican see anything obviously wrong (I couldn't last time I looked into this).

R.

545454 · November 2018

If it's not returning to pitch, it might be the trem block rubbing on the cavity somewhere. I had a similar problem with a Squier - was able to sort it just with a bit of sanding at the contact point. Also, is there any contact between the bridge and pickguard? That might have the same effect, just preventing it returning fully.
There's a guy on Youtube (Frudua) who has a couple of excellent videos on setting up a vintage-style trem. I've gone through his process on a few strats, and every one has excellent tuning stability afterwards, even on cheapy import trems.

EDIT: this video

but think you need to watch it alongside the one on the 2 pivot modern bridge for all the details

robinbowes · November 2018

Thanks - I'll give them a watch.

mbe · November 2018

What are the trem pivot screws like? I've noticed on some cheaper trems the thread goes all the way to the head instead of having a section of plain shank for the plate to pivot smoothly.

robinbowes · December 2018

mbe said:

What are the trem pivot screws like? I've noticed on some cheaper trems the thread goes all the way to the head instead of having a section of plain shank for the plate to pivot smoothly.

I did wonder if they were maybe a bit loose.

I'll re-string over the weekend and see if I can improve things.

R.

mbe · December 2018

robinbowes said:

mbe said:

What are the trem pivot screws like? I've noticed on some cheaper trems the thread goes all the way to the head instead of having a section of plain shank for the plate to pivot smoothly.

I did wonder if they were maybe a bit loose.

I'll re-string over the weekend and see if I can improve things.

R.

It's more the type of screw than the tightness.

If the thread goes all the way to the head of the screw then the edges of the plate are pivoting on the thread helix instead of a smooth section at the top of the screw. This can cause the trem plate to bind on the screws and make it harder to return to correct pitch.

robinbowes · December 2018

mbe said:

robinbowes said:

mbe said:

What are the trem pivot screws like? I've noticed on some cheaper trems the thread goes all the way to the head instead of having a section of plain shank for the plate to pivot smoothly.

I did wonder if they were maybe a bit loose.

I'll re-string over the weekend and see if I can improve things.

R.

It's more the type of screw than the tightness.

If the thread goes all the way to the head of the screw then the edges of the plate are pivoting on the thread helix instead of a smooth section at the top of the screw. This can cause the trem plate to bind on the screws and make it harder to return to correct pitch.

By "loose" I mean that the plate seemed to move around, as if the screws are too thin.

They don't have a thread all the way to the head of the screw.

R.

mbe · December 2018

That should be OK.

ICBM · December 2018

robinbowes said:

It seems to stick in two positions, depending on whether it's pulled up or pushed down.

That sounds like an issue at the bridge not the nut.

Check that no part of the bridge is touching any part of the body, including the pickguard as 545454 said, and look right inside the rear cavity - sometimes it can be touching the front wall... which is a bit of a pig to fix.

It should be fairly loose on the screws, that isn't the problem. Are the screws overtightened? If the bottom of the bridge rubs on the top of the guitar that will do it. They need to be raised far enough that the bridge will sit fully flat on the top with no string tension on, and then tightened so they *just* touch the plate but don't lift the back edge of it. It can make it easier to get right if you raise the middle four screws, but other than that there is no advantage to doing it, the pivot point just moves down the shaft a bit. Ideally you want all six perfectly adjusted.

Contrary to popular belief, when the bridge is set up properly to float, it should not be touching the body at all - the only contact is on the pivot screws.

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Improving a Pacifica trem

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