Gotoh Floyd Arm Question

[whitebison66]

Can anyone tell me how to tighten the brass knurled nut beneath the plate?It has a tiny bit of movement that translates into rattling when I pull up on the arm and let go. I also don't like the sloppiness of it. It's not a lot, but I prefer the arm to be immobile.

It is NOT the 2.5mm allen screw at the bottom of the arm assembly. It the thing that looks like the illustration, located directly beneath the plate. I can't figure out how to tighten the doggone thing...

Thanks in advance!

 

[blue313]

Don't tell me someone other than Gibson uses those knurled things...

Can you get a strap wrench in there?