XC90 whine
 

Is there a front differential oil change as well as a bevel/angle gear oil change I could do?
I have a background whine which I've been discussing on the XC90 section but looking at a post on this AWD section I saw mention of changing front differential oil which I have not done. I have changed the bevel/angle gear oil which was in a terrible state but could not see where to access front diff. The left front driveshaft weeps a little so front diff oil could be low.

The front differential is an integral part of the gearbox and shares the same oil.

There isn't a "centre diff".