Opinions please on an input shaft.

[Nilao]

that looks like the tone ring for the transmission RPM sensor. the input shaft should go through there. If they installed the bearing and didn't shim it for the proper end play and lash then it could be chattering the bearing. I doubt I'd trust the workmanship of anyone who can't remember to put the clutch disk in before installing the tranny and then breaking my pto pump.