R32 Gtr Rear Leak

[Sleepy_R34]

So I recently bought a R32 GTR and noticed a leak from the back. Popping my head under the car my first thought was the diff as the whole finned area was saturated, but looking a bit closer it seemed it might be the hicas dripping onto the diff. After jacking it up, it seems the leak is coming from just above and in front of the hicas bar. I took a video which might be easier then explaining, can anyone tell me what part this is and how I fix it?

[RBN1]

There is a breather on top of the diffs. They sometimes start leaking. Do a quick search they should have been discussed before.

[Sleepy_R34]

Okay I've done a bit of a search, after looking at where the breather is, it is right beneath the bushing that has oil on it, so I am imagining the oil is squirting onto it, but can the oil really squirt out that high?

If it is the breather, what are my options? I read that sometimes dirt can keep it open, so maybe give it a good clean. Over filling? If so how do I know what the right amount of oil to use is? or do i just leave it, as it is sort of doing its job? I would prefer to stop the leak though haha