check to see if one of your motor mounts came loose, if it did, it could have caused the shaft and engine to be out of alignment and chewed up the driveshaft. try to shake the motor by hand, it should have a slight give, but not feel loose. it seems like maybe the PTO wasn't greased, wore out the splines on the shaft, and then once it finally stripped the vibration took out the carbon seal maybe? did you say that the jet pump spins, but makes a crunchy sound? if so, that is bad, you probably need a rebuild on the pump at the least if not all new stuff (bearings, seal, shaft, oil) when you pulled the driveshaft out of the PTO, was there any grease on it? in the PTO boot? if there was the proper amount of grease in it, when it came apart as it appears it did, there would be grease everywhere