Probably a combination of things. Casting flaw, probably. Maybe also too much belt tension? Color of the break looks odd, almost yellow? Maybe it's just my monitor?
Take another look at the snout, see the older looking crack running from front to back. This is what I tought, bad casting and probably was cracked from installation of new bearing and seal. This probably weakened the other area.The yellow looking stuff is where the casting started to rust right away. :read2: