Odd final drive oil ?

[Deleted account 250319001]

Decided to change my final drive oil today. (GSA 15)
First, when i drained it out, It measured 210Ml. I phoned the dealership to confirm the 180Ml.
They confirmed 180Ml. I pointed out they changed the oil at 600 miles, so overfilled it!
Or did they change it?
The oil was black, My 1150GS was as clear coming out as it was going in. And the Magnetic screw was full of swarf. So i'm doubting it was actually changed at 600?
Glad i change it annually instead of every two years. Only takes 15 minutes.

 

[batman1]

What is the correct grade diff oil?

 

[Deleted account 250319001]

75W90 GL5 fully synthetic. I use Castrol Syntrax but there are other manufactures. I also had a nearly full bottle. But it was dated 2011.So binned it.

 

[jefformston]

Some folk have too much money. Why bin an open bottle of oil, it's not going to go off?

 

[Shunt]

It will be black the first few times, as there cutting themselves in.

 

[Schtum]

What is the correct grade diff oil?

In the interests of semantic precision, can I just point out that although it's often incorrectly referred to as such, it's not a "diff". It doesn't perform any differential function.

 

[Deleted account 250319001]

Some folk have too much money. Why bin an open bottle of oil, it's not going to go off?

Chemicals and additives begin to separate after a couple of years. So five years was way too long out of date. I read the thread on here from a guy that work at Castrol.

 

[Deleted account 250319001]

In the interests of semantic precision, can I just point out that although it's often incorrectly referred to as such, it's not a "diff". It doesn't perform any differential function.

Correct, However, the 75W90 GL5 is described as a "Diff oil" suitable for cars & Light commercial vehicles. So in the "interests of semantic precision" he was referring to the oil and not the Vehicle ?