BMW F10 xDrive transfer case oil change
Does the F10 xDrive's transfer case oil need changing?
According to BMW's instructions the oil is changed when the control unit gives an oil-related fault code, and the code can only be seen by reading the car. In practice, the change is a cheap first step against jerking. It does not remove mechanical wear, but often only buys extra time.
Does the transfer case have a drain plug, and is one change enough?
The ATC350 box (up to 9/2011) has a drain plug under the bottom plate. The newer ATC35L has no plug, so the oil is sucked out and the box cannot be emptied in one go. Therefore do several changes in a row and drive for a short while in between; three changes were mentioned as enough. Calibration is done after the change.
What oil goes in the transfer case?
The recommended oil is BMW DTF 1. Ravenol TF-0870 has been used without problems. Valvoline MaxLife MTF GL-4 75W-90 oil was not recommended, because its viscosity does not match the transfer case requirement.