Well is it possible the actual rear shaft on that one side was bent in some way and not the housing, to damage the housing I would have needed to hit it pretty hard and I have not done so, ever!. Maybe the shaft is just bad? Maybe.

Exhaust manifold, IT has 207K on it, Actually it has that pretty cool rumbling truck sound at the moment but I can tell it sounds a bit rough for normal, if that make sense.