I hear you on the back issues. The damaged/bulging disc in the back of my neck has been pinching down on
the main nerve trunk lines that go down both arms for years now and working over shoulder height with my
hands is seriously painful.
Sounds like you a bit and I'm sorry you suffer that too.
Oh - you might find the other ball for the z-bar on the bellhousing, actually.

Seriously though, if you pull the "cotter" u-shaped pin thingy like others have said and then grab the bar with
something like a pair of vice grips and try to move it laterally back and forth, you'll find it plops right off the
bellhousing pivot ball (if you have the other end unbolted and lifted up off the frame mount, that is).