Jerry,
I don't think I have ever seen a hyd pump fail like that, something had to have gotten into it to jam it causing it to lock up and break the input shaft. I suppose if the bushing failed and the shafts got that loose they might not mesh or the gears climbed each other. Probably so torn up now that you could not figure it out.
What brand of hyd pump do they use.
On my 06 Thunder I change to filter to a much larger unit. I asked the tech's at Filtri about the by-pass always lifting on the filter housing and they said the the orig filter is way to small so I went to a larger unit. It still lifts the bypass when the oil is cold which they say is normal. Was thinking that when that bypass is open a piece of metal from somewhere could get into the tank and from there straight into the pump,,,and bang. Oh! and of course will happen 6 miles west of nowhere, with no cell service.