I've not seen the problem on the facelift but the sound did exactly match. I've pulled the front shaft off x-drive before and the system just worked and shut off the front axle.

I'm wondering if you have an additional issue like worm gear on the tc motor so it's not disengaging so it's reverting to old school always on.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)