Fender (well, Squier) factory shim?- (JV Precision) UPDATE- Truss rod now out.

[cameltoe]

Just bought my first JV series P bass, (separate thread on here) and have taken it apart, given it a good clean and set up to my liking, and noticed a shim in the neck pocket which appears to be factory fitted?

A quick google for 'JV bass shim' indicates the manchester guitar tech also found one in a JV P bass. It looks identical to mine.

Why is it there? My bridge has more than enough adjustment without it- I always considered a shim to be a way of lowering action when the bridge is at max adjustment but this isn't the case.

Should I take it out? Is there a downside to having it?

I've adjusted the action how I like it, and there is now a minor fret buzz on the E and G strings [b]when fretted[/b] from 14th fret up, however the action up here is now [i]very [/i]low.

Around the 8-12th fret the action is still a smidge too high - would removing the shim improve this, i.e give me more clearance higher up the neck to reduce the buzzing, while allow the action to be set a bit lower on 8-12th?? I've been trying to work out string clearance vs neck angle in my head and i can't do it.

Or should I just leave it alone??

Truss rod is now adjusted perfectly btw, so should be no issues here.

Thanks in advance!

Edited January 31, 2014 by cameltoe

[HowieBass]

The fact that you're now getting fret buzz might be due to the absence of the shim. Was it at the front of the neck pocket? I've raised the neck on my Curbow 5 because my bridge saddles were bottomed out and the action was too high but I used a full neck pocket shim - a shim just at the front of the neck pocket will angle the neck up a little which might be what you need.

[cameltoe]

No I haven't removed it- I've left it there.

It's right at the back of the neck pocket.

When I compare it to my RW Precision, which doesn't have a shim, string-over-fret height seems fairly consistent from 8th fret right the way up the neck, with no buzzes anywhere when fretted and a very low action. However with the JV- with the shim present- the action is higher at the 8th than it is at the 15th. noticeably so, meaning to get the action where I like it over the 8th fret, for instance, results in a very low action at 15th and this understandably causes buzzing when fretted from roughly 13-14th fret up.


Just wondering if taking the shim out would improve this and if anyone could shed any light on why it's there from factory really.

[HowieBass]

I imagine factory shims are there because the neck + pocket geometry isn't quite right for that instrument but the location with yours is causing the neck to angle back and is probably causing the issues you've encountered. It won't do any harm to remove the shim and you seem to know what you're doing with setting it up... bear in mind it's a Squier so it probably won't have been given the fullest of attention when first set-up after assembly and the shim might be unnecessary for how you like a bass to be set up.

[Martin E]

Removing or moving the shim will not solve your problem.
Are you sure your truss rod is adjusted correctly? Buzzing at the high frets and your description of string heights would indicate too much neck relief.
Having adjusted that correctly the overall action will change and the reason for the shim may become apparent as your bridge adjustment may move out of it's normal range
of operation.

[Musky]

Removing the shim won't make any difference to the problem you're describing.

All the shim is doing is giving you greater adjustment at the bridge by increasing the back angle of the neck. Remove the shim and you'll get a higher action, particularly at the higher frets. When you lower the bridge to correct this you'll be back to where you started with the fret buzz.

I'd be looking at the relief and/or the fret heights.

Edit: Martin beat me to it!

Edited January 4, 2014 by Musky

[cameltoe]

No the relief is set perfectly now, how I would consider it to be anyway.

What I was considering is if removal of the shim and the resulting change in neck pitch would drop action at the 8th relative to the 15th.

Above post states it will raise action especially at the higher frets- This is what I was wondering- if the higher frets are affected more by removing the shim, then this will allow a lower action at 8th due to increased clearance higher up.

[tedmanzie]

No one seems to agree on why shimms are used and if they work. There was a big thread on here a while back with seemingly knowledgeable people arguing for hundreds of words completely opposite points of view. I've talked to a luthier who thinks they are a waste of time and a luthier that doesn't.

For what it's worth I have two JV P-Squiers and one has a shim where you describe and the other doesn't. I'm not sure if the shim was fitted at the factory or later on. I just leave it alone!

Edited January 4, 2014 by tedmanzie

[Bassassin]

A shim in this instance might be to allow the saddles to be in the middle of their adjustment range rather than at the very bottom. My old SQ Precision had no shim when I got it & had no useable scope for lowering string height, and had about 7mm of potentially hand-gashing screws protruding from the saddles.

A shim can be used to induce a specific & fractional curvature or relief at the heel end of the neck, otherwise all it alters is the neck pitch. The angle of the strings relative to the frets stays the same, and is dictated by saddle height & truss adjustment - so a shim won't make any difference to action between the 8th & 15th.

Jon.

[mikhay77]

In theory you should not need a shim unless there is an issue with the neck.May need the frets dressing,you should be able to see any issues looking straight down the neck but if thats all ok , you say the string height is very low above the 14th fret and has fret buzz basically means the truss rod needs some more tension on it to raise the neck in the middle thus lowering the action in the centre of the neck.Then you can raise the saddles a gnats to stop fret buzz at the top end then finally reset the intonation, Seems to work for me!

Edited January 4, 2014 by mikhay77

[mikhay77]

Oh forgot to ask,what strings are fitted? If it has tow ropes it does make a massive difference. I play 30s to 90s and whenever I get a new bass I have to mess around with the action a bit once I fitted the skinny strings!

[Musky]

[quote name='cameltoe' timestamp='1388836518' post='2326568']
No the relief is set perfectly now, how I would consider it to be anyway.

What I was considering is if removal of the shim and the resulting change in neck pitch would drop action at the 8th relative to the 15th.

Above post states it will raise action especially at the higher frets- This is what I was wondering- if the higher frets are affected more by removing the shim, then this will allow a lower action at 8th due to increased clearance higher up.
[/quote]
Removal of the shim would have have exactly the same effect as raising the bridge, i.e. raising the action. Because you're adjusting from the body end the greatest effect would be seen at the dusty end but it would also raise the action on the lower frets, e.g. the 8th.

You've effectively got a lever arrangement with the fulcrum at the nut, like in the right hand picture below.

To change the action you can raise or lower the upper line (the strings) with the bridge, or you can raise or lower the bottom line (the neck) by shimming but in either case all you're doing is changing the angle of the strings relative to the neck. You can see that you can't simultaneously drop the distance between the neck and the strings at the 8th fret whilst increasing it at the 15th by adjusting the angle.

[Jus Lukin]

-

Edited February 19, 2022 by Jus Lukin

[cameltoe]

Right guys, I've taken your advice and tried to straighten out the truss rod a bit more. It looked fairly good before, but I thought I would see if I could get the neck a touch straighter.

The truss was very tight to move, 1/4 turn then left a few hours to settle made no discernible difference to relief, so I tried again with 1/2 turn. Left overnight, no difference. Both times it appeared to have moved ok on retuning, but when settled had returned to as it was before. Tried one more 1/2 turn, left to settle, same result.

Removed the neck fully last night, released the truss nut completely and greased, re-tightened truss again and it snapped. Seriously. It's sheared off right under the truss nut.

Holy f***

If someone has any helpful advice right now, or just an optomistic comment I'd love to hear it as I'm feeling this could be damage beyond repair and I've just destroyed my new bass.

I can't believe it.

Edited January 5, 2014 by cameltoe

[Thunderbird]

Oh dear whoops hope you get it sorted but I think the neck is now mullered

[cameltoe]

[quote name='Thunderbird' timestamp='1388931886' post='2327727']
Oh dear whoops hope you get it sorted but I think the neck is now mullered
[/quote]

Not exactly full of optimism but thanks anyway Paul!

Hoping my Luthier may be able to do something with it. I really don't want to have to get a new neck.

[cameltoe]

Here's hoping my luthier has got one of these;

http://www.stewmac.com/shop/Tools/Special_tools_for_Truss_rods/Truss_Rod_Rescue_Kit.html

That looks like it would work as mine has sheared right where the nut ends.

Otherwise maybe somewhere like Mansons would have this kit and be able to carry out the repair.

[Grangur]

Take it back to where you bought it and play naive.

Let's be honest; a shim is a "work-a-round" or "bodge" to make up for the manufacturer routing the pocket too deep for the neck or at the wrong angle, so not allowing you to otherwise get good action. What you have is a bad bass.

Your approach needs to be that you were unable to adjust it in accordance with the makers instructions and it's not "fit for purpose" as described in the "Sale of Goods Act".

Good luck.

Edited January 5, 2014 by Grangur

[Fionn]

[quote name='cameltoe' timestamp='1388788548' post='2326206']
Is there a downside to having it?
[/quote]

Of course. It's a fundamental design flaw that such things should be necessary to experience a playable action on an instrument. It perplexes me, that instruments of this apparent value are so compromised. A shim lessens the structural integrity of the neck to body join and affects the transfer of vibration (thus resonance) through the instument, fact. You might as well make a bass from plywood if bodge-jobs like shims are built into basses.

[LukeFRC]

[quote name='cameltoe' timestamp='1388836518' post='2326568']
No the relief is set perfectly now, how I would consider it to be anyway.

[b]What I was considering is if removal of the shim and the resulting change in neck pitch would drop action at the 8th relative to the 15th.[/b]

Above post states it will raise action especially at the higher frets- This is what I was wondering- if the higher frets are affected more by removing the shim, then this will allow a lower action at 8th due to increased clearance higher up.
[/quote] yes it would [quote name='cameltoe' timestamp='1388929886' post='2327698']
Right guys, I've taken your advice and tried to straighten out the truss rod a bit more. It looked fairly good before, but I thought I would see if I could get the neck a touch straighter.

The truss was very tight to move, 1/4 turn then left a few hours to settle made no discernible difference to relief, so I tried again with 1/2 turn. Left overnight, no difference. Both times it appeared to have moved ok on retuning, but when settled had returned to as it was before. Tried one more 1/2 turn, left to settle, same result.

Removed the neck fully last night, released the truss nut completely and greased, re-tightened truss again and it snapped. Seriously. It's sheared off right under the truss nut.

Holy f***

If someone has any helpful advice right now, or just an optomistic comment I'd love to hear it as I'm feeling this could be damage beyond repair and I've just destroyed my new bass.

I can't believe it.
[/quote] ouch. was it the nut or the rod that's gone. Apparently the nut is replaceable whereas the rod is harder.... remember it's japanese so therefore metric screw threads.....

[Grangur]

[quote name='LukeFRC' timestamp='1388934064' post='2327758']
ouch. was it the nut or the rod that's gone. Apparently the nut is replaceable whereas the rod is harder.... remember it's japanese so therefore metric screw threads.....
[/quote]
In any case he needs to take it back and make it Fender's problem. He should demand a good replacement bass.

When making a bass Fender have a massive stack of necks and an equally massive supply of bodies. All should be virtually identical. I can't believe they can't find a body and neck that work well together without bodging it. If one neck doesn't work, they should change the neck. It's shockingly bad they should let a bass go out needing a shim from day 1.

[HowieBass]

I'm really sorry to hear this when it seemed to me that you might have had enough relief but just incorrect neck angle because of the shim.

I guess that now you've got to get the bass to a luthier they will make a decision on whether to retain the shim or not. Best of luck with getting it sorted.

[Paul S]

[quote name='Grangur' timestamp='1388934776' post='2327768']
In any case he needs to take it back and make it Fender's problem. He should demand a good replacement bass.

When making a bass Fender have a massive stack of necks and an equally massive supply of bodies. All should be virtually identical. I can't believe they can't find a body and neck that work well together without bodging it. If one neck doesn't work, they should change the neck. It's shockingly bad they should let a bass go out needing a shim from day 1.
[/quote]

If it is a JV Precision then it isn't new, it is around 30 yrs old and bought second hand.

Ouch.

[cameltoe]

Needless to say I couldn't give a toss about the shim now!!

The rod has sheared with a bit still screwed into the nut.

Obviously the rod was defective, as it was hard to turn and was not keeping tension in the neck once it had resettled, but looking back now I'm thinking could I have just lived with it?

Seriously, can a rod be replaced? Skunk-stripe neck.

[Thunderbird]

[quote name='Grangur' timestamp='1388934776' post='2327768']
In any case he needs to take it back and make it Fender's problem. He should demand a good replacement bass.

When making a bass Fender have a massive stack of necks and an equally massive supply of bodies. All should be virtually identical. I can't believe they can't find a body and neck that work well together without bodging it. If one neck doesn't work, they should change the neck. It's shockingly bad they should let a bass go out needing a shim from day 1.
[/quote] All the shop will say is that an unauthorised repair person worked on the bass and broke it which I think would be a bog standard reply I really am trying not to be negative but I just cant see the shop paying out for it and the bass is not new if it is a JV it must be about 25-30 years old anyway hopefully Will can get his luthier to fix it