The real question is why would the OP run into a random pinion bearing bolt while addressing a main bearing issue?
He did mention an 8 year old "parts organizer".
That brings back memories to when I was a kid - maybe younger than eight. My brother and I were at my grandparents' farm. My grandfather was a tool and die maker and had all kinds of cool stuff.
Well one day we found a cabinet with a zillion drawers. Each drawer was filled with nuts , bolts, washers, fasteners, etc. We started playing with all the neat little pieces.
Later on my grandfather confronted us about mixing up his "washers". We vigorously denied having anything to do with any washers. He kept on us and we kept denying it. He was very disappointed in us for "lying".
It wasn't until years later that I realized what he was talking about. We didn't know what the word "washers" meant. We thought he was talking about some sort of cleaning stuff or the washing machine. We'd never heard of little circles with holes in them called washers, before.
