It should not. In the old days, I think that some people would put sawdust in the rear end to lesson the noise in an old differential (and, then sell the vehicle).
http://www.jalopyjournal.com/forum/showthread.php?t=489889I guess you could also service the differential and reset clearances and replace bearings/bushings (and hope that makes a difference).
Or, spend several hundred dollars and put in a 3.55 ring & pinion set with new bearings/bushings. I did this for better cruising, and my already quiet Suburban became even quieter.
