Get a low mileage front diff.
I helped a friend replaced the front diff in his 2004 X3 E83 3 yrs ago (in 2022) and wrote it up in the link below.
Should be almost identical for E53 X5...
DIY: 2004 BMW X3 Front Diff Replacement @165K miles
https://www.bimmerfest.com/threads/d...miles.1436496/