How often? Mine is a Sierra diff, how do I empty it? I see it has a filler cap on the top but that seems to be it?

I've searched the forum for "diff oil" but couldn't find this. I've found recommendations on what oil to use, though.

Cheers,

Alex

There's a (10mm?) Allen key socket on the back. Open this and tip/drain the oil out.

Cheers,
James

You could use a big syringe or hand pump and a short bit of hose to suck it out.

My sierra Haynes manual suggests a hypoid 90 oil, such as duckhams. I have just put Castrol 80-90 in mine. 1 litre seems to be enough.

Thank you guys.

How often am I supposed to replace it?

Cheers,

Alex

Just top it up to the right level unless you have the diff out of the car. There is no service interval for changing the final drive oil.

Excellent, thank you!