Re: Why is my Jem 7vwh a piece of S***?
You only need the shim if you want to pull up a perfect fifth on the edge alone, lol.
Just let someone else have a crack at it, late 90's to '03 are my favourite 7vwh's, I ADORE the ebony, I'd really love one. I don't think there is such thing as a bad year for JEMs, just different years for different specs.
If you want one last go at setup, here's a couple of indicators... Check the string height in three places.
1. The Nut: fret the 3rd fret and tap the string over the first fret, the string should just kiss the fret, i.e. you shouldn't hardly be able to see a gap between the fret and string, but it will make a click if you tap it with the end of your finger. if it's too low, put a shim under the locking nut. If it's too high, there's probably a shim under the nut already, in which case, try removing it. I've done this a couple of times, and even ended up using the nut shim in the neck pocket - we'll get to that.
2. The Truss Rod: the truss rod only affects the height of the string between the 2nd and 10-12th frets (believe it or not). Fret the 2nd and 12th frets and tap the 7th fret. There should be a little more relief than the nut test (lol, nut test) but you should barely see a gap between the string and 7th frets. if there's more, tighten the truss rod, less or the string is touching the 7th fret, loosen. The truss rod needs to be adjusted when the guitar is fully in tune with all the strings!
3. The bridge: likelihood is if the bridge screws are all the way in, there will be hardly any pull back on the trem. The bridge height only affects the action above the 10-12th frets. Fret the 12th fret and look at the 24th, there should easily be twice the relief than the 7th from the last test, but you can keep adjusting this to get the level of 'acceptable' buzz. Electric guitars will always buzz acousticly, it's important to gauge the level of buzz through an amp.
Other things to bare in mind; the Lo Pro edge does not lie flat as it initially looks, it's the knife edges you can see at the sides that should be parallel to the body, the sides of the trem will be angled off the body slightly.
As for shimming the neck, all American JEMs should already have shimmed necks. Shimming the bottom of the pocket - nearest the pickups - is equivalent to lowering the bridge. The necks are shimmed because by raising the bridge posts off the body, it allows you to pull the trem back further into the body.
I tend to make sure I don't use more than three springs, having fewer springs makes the trem move more easily. Having 2 and screwing them further into the body will make the trem really soft, having 4 springs at less tension each (same overall tension) will make the trem harder to move.
Hope this helps!