I bought a 2020 Crestwood reissue from someone who removed the trembar for shipping and sent the pieces in a Zip-loc bag. To be fair, he wrapped the trem bar itself in a paper towel to protect it. I haven't found any support on the internet for how to assemble it (no instructions I can find and no photos detailed enough to convey an idea of what the assembly process should be). The seller simply gave me a sequence of parts, which doesn't work very well: it's a two-dimensional description of a three-dimensional assembly.
The parts are a screw, two white plastic washers, a nut, a spring, and a soft disc (rubber?), beside the trem bar piece itself. The spring fits between two parts: a circular seating on the guitar body and a metal piece that clamps onto the trem base. The clamp is tightened by means of a screw. The latter clamping piece has the other circular seating to hold the top side of the spring and this is what the dissasembled group of trem-bar parts screw into through a hole in the circular part of the clamping piece. Together, the clamping piece and the trem-bar group act as a lever to give you vibrato ("tremolo").
I have no idea if I assembled it correctly and I worry especially about the screw falling out. It doesn't seem like there is anything to keep the spring in place if you pull back on the trem bar (to raise the pitch). Any suggestions?
Here's what I did: Since the parts were for the trem bar alone, the initial problem was putting the nut onto the screw because the screw sits down inside the spring (I am guessing). The spring is about twice as long as the screw. You would need tiny tiny fingers (and the dexterity of an octopus) to screw the nut on while holding the spring in place. So, instead of putting the nut on the screw and attaching it to the guitar all at once, I loosened the screw for the clamp (on the trem base) and then removed that clamp piece. Then, I assembled the trem-bar group of parts on the clamp separately. Having not one, but two washers, I put one between the trem bar and the screw head and one between the trem bar and the clamp. Finally, I reattached the clamp to the trem base. I had to remove the neck pickup volume knob to get the clamping piece off and back onto the trem base.
It was no fun trying to keep the distance between the two ends of the spring housing as small as possible at the same time as fitting the whole clamping piece + trem bar assemblage back on again. As far as the spring housing goes--in other words, the space between the clamping piece and the seating on the guitar base--I put the rubber disc against the top/clamp circle, then inserted the spring, but now I wonder if the spring will stay inside its housing, given that I sort of assembled the whole thing blindly.
Thanks!