Noise from rear axle
 

Hi, I`m the owner of a 2003 mod. SL500, having 2000 miles on the odometer. While coasting at appr. 50 mph and 1500 rpm, I notice a humming noise from the rear axle. As soon as the speed drops slightly below 50 mph the noise is gone. When accelerating from a speed below 50 mph to a speed above, there is no noise while passing through the appr. 50 mph band. As the noise is present only at this narrow speed band and low contact forces between the ring gear and pinion, I wonder if the noise may be due to some resonance phenomena in the differential at this frequency and load. Hopefully no serious problem is to be expected.

Has anybody out there experienced similar problems? Any feedback will be appreciated.