I think maybe someone tried to weld the pedal onto the shaft.
The shifter bottomed out in back, so I couldn't shift out of neutral. So I loosened it to turn it cc forward, then tightened it as tight as possible. Now it slips. Took the floor assembly off in order to get the pedal off the shaft to see the splines but can't slide it off, that's why I'm wondering if it got welded at some point. Look like it?