I have all wheel drive.
The Haldex is like a transfercase?
I understand were the angle gear is.
So the haldex is in the area were the transfercase would be like a 4x4 vehicle.
Not really. A transfer case is usually only used on longitudinal mounted engines and is mounted to the back of the transmission. So it is more like the angle gear in a way.
In the simplest form all a haldex does is connect and disconnect the rear wheels from the drive shaft. The xc90 is FWD biasd vehicle. meaning the most of the time the rear wheels are not receiving any power from the engine. When the car detects a difference in speed in the front wheels vs the rear wheels (traction loss) the haldex engages the drive shaft and the rear wheels receive power. This is the basic principal anyways.
Here is a picture of the xc90 system (all wheel drive clutch = haldex)
here is a typical 4wd setup