I have a Fender MIM Precision and noticed today that I kept having to tune the E string up. When I checked the tuner, I noticed two things; the tuner was loose and there was a piece of black plastic sticking out from under the gear. I found out this was some type of shim that goes around the shaft and under the worm gear and of course its broken. I' ve searched the web and can't find anything about this. Can anyone tell me where I can find, or make, a replacement and if its even necessary? I never saw these on older Fender's and it's got me baffled.