Hello Have changed my rear differential gear oil and noticed that the differential on the cardan shaft was damp but dried up! Clean this off and change the oil! Now after 2 weeks I discovered 5-8 drops on the garage floor and looked under the car and it comes out easily below the cardan shaft! I mean that the Simmerring or shaft seal ring of the differential is old porous! How can one change such a removal part number ect.????!!! For pictures and part number I would be s Thank you very much