gearbox oil leak on a4 multitronic box

[pcrpaul]

Can anyone help? Audi multitronic box leaking oil out of breather and was told it must have internal problems £1,200 just to strip down to see, so I found another box for£800 .just had new box fitted and this one is doing the same.so im told it must be gearbox oil over heating, is it just a matter of replacing oil cooler?