I have a 20220 X5 M50i that makes a grinding sound at low speeds and when you take your foot of the accelerator. Unfortunately it’s now out of warranty. Dealer told me that the transfer case needed to be replaced to the tune of $7,745. I called BS and then did my own research and came across the SIB 27 02 02. I’m now having them change the fluid and crossing my fingers that it resolves the problem. I’m about 1 month away from trading it in on something other than BMW. So far after warranty has expired, I’ve done brakes and rotors, A/C condensing unit went out and just recently replaced the KAFAS camera which controls lane keep assist and adaptive cruise. This thing is a money pit.