A grinding noise may be heard coming from the differential during slow cornering.
This noise is best heard during tight cornering situations; for example, while parallel parking, driving in a tight circle, etc
When the rear wheel speed differential varies during tight cornering, a slip stick effect is created on the lining and steel discs incorporated in the differential locking clutch, causing the grinding noise.
This noise typically goes away as the locking clutch discs in the differential are broken in.
The break-in time varies depending on driving habits; for example, tighter cornering (working the locking clutch) means that it takes less time to break in the locking clutch discs.
IF THE TECH CAN VERIFY THAT THIS IS THE NOISE
differential oil should be replaced with:
83 22 2 282 583
Special differential oil kit
e46 differential = e92 differential with bigger cooling fins. there has been a small percentage of people who have had concerns on slow tight cornering such as parallel parking a groaning type sound is heard from the rear differential. Since this is a same issue known with e46 m3, e60 m5, e63/54 m6 and e90/92 m3. a 'special' differential fluid is used
BMW Certified Diag Tech.