[David3]

Well, I get to replace my transfer case on my '12 550i Xdrive. The issue started as a 0% throttle whine. Ultimately progressed to fairly significant drive train bucking mostly at 0% throttle but also during spirited acceleration. So, wanting to do this myself, but information on line is scarce. And, it seems that both the ACT 350 and 35L are listed as a fit for my model/year. The ACT 35L seems both more plentiful and cheaper.

My question is whether or not the ACT 35L is the updated and proper transfer case model? Anyone ever replaced the transfer case on an F10?

BTW, I disconnected (power/controls) the transfer case control module and the noise and bucking are gone...except for very spirited acceleration. Of course I get a slew of warning lights: ABS, 4x4, parking brake, and adaptive cruise does not work...all to be expected.