I am new to the forum but have been browsing for some time. As stated above we have a 590i S4 and it will not shift out of 2WD and into 4WD or Diff lock. The cable is still intact and I followed it down to the back section of the front differential. I can’t get that lever to move despite a good soak in Kroil penetrating fluid. We rarely use the 4 WD option. Am I looking at a new part? If so what would you try first to “free it up”.