I am trying to remove a gear (approx 3 inch Dia) from the end of a ball
screw (approx 1-1/4 inch). It seems to have a taper pin, at least the
manual shows a taper pin. the head of the pin is rounded and sticks out
about 1/32 from the collar of the gear. there is a through hole on the
other side of the collar , which is empty. I have been trying to punch
the pin out from the 'hollow'.

I have tried everything I can think of except heat (there is a risk of
fire in this location). I made a punch , got a big hammer and had a
mechanic try to loosen it, no results. I then built a device alot like
a 'nut splitter'. thinking it could 'push' the pin out. I made it very
heavy duty and used a hardened drive screw , again no results. (except
broken tool).

is there a trick ? or a hydraulic tool I should buy ? or a magic spell.
FYI I am doomed if I can't remove it.