im positive that it is the vent, even though it is new. i had the seals replaced and there is no leakage from there. i could tell that it is from the vent because somehow the oil still manages to make its way all the way up to the relocated vent and leaks out of the vent and runs down the hose. im not sure if the oil is foaming or what. and the case is definitely not overfilled, because after the 5th time of draining and refilling i was extra careful in making sure nothing was coming out of the fill hole befire putting the nut back in.