How much oil for my tranny?

[Rune]

I have a Posche 915 tranny in my 40 , and I'm going to change the oil . Then I need to know the amount of oil used here. I asume that someone on the forum use this tranny and know how much and whitch oil to use . I thougth of using a Castrol gear oil.
Hope someone can help, because there is dripping some oil from the box , and I do not know if last owner followed up this.

Rune

 

[Pete T]

The factory manual states 3L (6.34 US pints) without a cooler
3.1L (6.55 US pints with a cooler