s4 transmission oil change Qs

[therealnovaboy]

I was if anyone new the service interval for changing the rear diff oil ? I cant find this info anywhere.
Should the gearbox oil be changed at the same time or is it a matter of only checking the level and topping up where neccessary?
Also is there a drain plug on the diff to drain the oil or do you just have to pull out the shafts?

 

[aragorn]

I suspect like the gearbox itself Audi regard it as a "filled for life" component.

I'm sure there is a drain plug on the bottom.