Spun an axle shaft? What do you mean by that?

I've seen shaft's pulled out of the race truck that are twisted 30* from straight and they don't make noise. Popping is caused from something binding up then letting go really fast. Failed bearings usually don't bind and let go, they sound more like grinding.

I bet you have a foobared spider gear. Pull that cover drain the fluid and do a very meticulous inspection.