fordson major hydraulics question?

I have a Fordson Major Tractor, 1958ish I'm not positive on that. I have a bucket on the front. I was working with it and suddenly the hydraulics quit working. I took the front end apart a bit and I can see the pump shaft is loose. (It slides back and forth a half inch). The shaft is like this, Its got four bolts on the front pulley of the engine, the shaft is connected to them, the other end of the shaft is connected to the pump. I can hear it rattles when it runs. It looks like the bolts aren't tight on the pulley but they look like they might be right???? Is it ok for the shaft to slide should it be tighter