Yes, I see in your photo that you have the "level" plug on the carrier. I have the vent on the axle tube that I use to fill, and a drain plug on the bottom of the housing. That's it. I *Do Not* have that plug on my carrier (circled in red). Without this plug on the carrier or on the back of the housing, I don't know how much
oil to put in.
I will try to attach a barb/hose/filter to my vent hole like you have done here to help decrease the leak, but that still doesn't help with the
oil fill level.