What happened to your issue? I have same problem
Hello, I just came across your post regarding broken transfer case. I just had the same thing happen to my wife's X3. I am just over 50K and called BMW Assist with the issue. They said that if I have the car diagnosed by BMW they will look into what can be done to cover the cost but would bot promise and % of coverage.
I have a diagnostics code which says the servomotor is faulty code: 5463 and there is also a 5F3A transfer case malfunction code of 5462.
I am interested in how things turned out. Let me know if you would please.