Did you know that the BMW X6 M has two types of fluids in the rear differential, not one, like all the other previous BMWs?
BMW's X6M Rear Diff. has two types of fluid...ATF on the outside, Diff fluid in the center
The Center Section (the Differential) is filled with BMW diff. fluid, while the two outer sections (electronically controlled) are filled with the BMW Transmission Fluid. The electronics govern the torque applied to each axle for maximum traction and power to the wheel.
P.S. Tilting the differential more than 45 Degrees, while removed will mix fluids from one chamber to the other, rendering the unit useless, which will have to be rebuilt.
