Well update - Driveshaft checks out, the symptoms I occasionally experience very sporadically which I *believe* are T-case related were not able to be reproduced. They road tested it a couple times. Honestly it could be transmission behavior since sometimes it feels like its hanging between gears. Confirmed I have the newest driveshaft (the one used on the F15 models as well) so mine isnt the part that grenades and the U-joints blow apart.
Its under CPO until July 2019 so we shall see if it happens, if so I will bring it back in.
Glad to have a "clean bill of health" for the most part -
My next maintenance regimen as she is approaching 69k miles, is a full ZF transmission service (ZF recommends to perform every 60k-80k miles max)
-ZF Pan/Filter and bolts
-Mechatronics sleeve, 4 bushing "sleeves", and the bridge seal
-Lifeguard6 fluid
I'm also going to be doing the front and rear diffs with Redline 75W-90, and I'll get the Xdrive T-case oil changed (BMW fluid only obviously), and the adaptations reset in the T-case module.
Then its on to the XHP Flashtool flashing of the TCU
