What is this bearing?

[chatwithtom]

WOW!
Totally not what I expected to see after looking at the remains of that bearing!
I can't see how even a dropped bearing from the factory could be that damaged and not have something else destroyed in the process.
At this point one would have to wonder if it wasn't done on purpose just to freak someone (me) out?

In any case, it looks like you have no damage and I see no reason not to clean out the crap and refill with fresh oil, then forgetaboutit.

Lucky you. Except for the scare part....

Yep, the only evidence of damage is to that metal under the bolts on the pinion ring gear. hopefully its just two days of learning and discovering and its the end of it. I am baffled as to how the bearing could fall off the end of a shaft because there are no shaft "ends" that I can see.