Allparts Tremol-No Pin Type

I've tried to get this unit installed by experiencied luthiers in my Kiesel SCB guitar twice. Both times they could not get this thing installed so that the friction against the rod in floating mode would not make my guitar unplayable. Is simply does not return back to correct pitch after using the bar. Using thumb screws is very difficult also. I've had a lot of expectations but had to throw it in the trash.

There was some friction in the receiving end of the tremol-no. Every time you used the trem it never returned to pitch.