Classic trifecta of warning lights came yesterday. Codes on DSC showed VTG internal failure. When transfer case servo was activated with diagnostics there was a nasty chunking sound at the end of the motion range. Today tackled the problem and crawled under the vehicle. Servo removed and taken apart revealed the suspect worn plastic gear. (Exactly like on the sample picture from internet.) Turned the gear 180 degrees and problem solved for now. Remains to be seen if I eventually have to get the repair set including a new gear from BMW.