Glad to see you brought this over here to UB.c . . this subforum can sure use a boost
Front wheel bearings are another high wear item for E39's, and can deteriorate in as little as 60k miles. Diagnosed as a low rumbling sound with slight vibration or knockback on the brake pedal, particularly at slower coasting speeds. The same part number is used on all E39's except for the M5. Not too complicated of a task, and you can find a DIY at bmwtips.com.