8.75 Axle vent

I went to check the fluid in my rear and while loosening the plug it was hissing real loud and gear lube shot out as soon as I got the plug out. I'm assuming my axle vent is plugged, but none of the parts stores have it.

Where can I get one from? It looks like a simple design and I even thought about making one, but I want the right piece in there.

Thanks,
Ben