I may have found an answer to my problem. I would like the opinion of the
esteemed wizards of the list.  When I cleaned the differential case the oil
seal for the governor mounted on the side may have been dislodged. As the
transmission pumps atf past the governor a failed or missing seal would cause
the differential to fill with atf.  Plausible?

Rico Dagastino
Munford, TN