LIII Trem Block question

[Craiguitar]

Hi all,
I notice on the rear of the brass trem block on my LIII there is a small gully into which a small metal pin is held with a screw. What's it for? Anyone?

 

[tbonesullivan]

That metal pin is the spring that the bottom of the trem arm snaps into. It rests in the groove at the bottom of the arm. There is also a grub screw on the bottom of the block that presses on the bottom of the arm to stabilize it. You can loosen that if you want the arm to swing freely.

 

[Craiguitar]

Ah, that makes sense. I haven't noticed that part on any of my other Luke's