My diff has decided that it wishes it was newer, so it's doing an impression of the later ones and pretending to have no drain plug. Seized solid!

I'll have a look at the X308 section shortly, but can anyone here give me a reason not to just suck the oil out of the fill plug (which does come out ok, thankfully!)?

Cheers

 

I recently changed my diff oil and had to take the same approach. The drain plug was crazy tight and not so accessible, as it's recessed inside a hole in the crossmember, I just siphoned the old fluid out with a cheap pump, fit for purpose. I got pretty much all the old fluid out and refilled as normal.

I don't really think any remaining old fluid would make any difference and it's a big improvement either way.