From the looks of your pics, I'd say someone has been inside the unit who did not know what the hell they were doing! Look at all that fookin' rtv squeezed out around the pan, the same thing went inside the pan and is floating around in the sump.
I don't care what novak sez, ya use gaskets properly applied on this stuff, not rtv!
Obviously the endplay/pre-load setup on the rear output shaft bearing is scruud. Had to have been that way before also, you just didn't know it. I'd venture whoever was inside that case left the yoke nut loose so the shaft would spin. Most likely rtv is smeared all over the shims also so there is no way to set this up without cleaning everything. The endplay/bearing pre-load is set through the selective application of shims.
The shims get a near transparent coat of something like coppercoat adhesive once the shim pack is determined. Rtv acts like a shim and adds to the tolerance stack in an uncontrolled manner. That creates the final seal on the perimeter of the output shaft housing.