Differential E90. A hole on the right top. Leaking when you turn it upside down.

[E90 learner 2]

Hello, I bought the second hand differential.  When I open the box, see lots of oil. I tried to investigate where the oil leak comes from. It is from here. Is this normal?

Please see video. Video of the Differential

[Eagle 1524]

Its a breather hole so its normal. It shouldn't really be turned upside down with oil in it.

[E90 learner 2]

Thank you.

I was thinking if you overfilled your differential, it will just overflow there?

 

 

[Jacko 2078]

There is a drain plug, a fill plug, and a breather.

Drain plug drains. Fill plug is where you put fluid in, when it comes out of the fill plug level its full. The breather is because as the fluid temp changes its level will change etc, and if it didnt have the ability to breath it'd blow seals etc.

Solution, dont invert diff  

Edited October 31, 2022 by Jacko