Rearend vibration?

Need to talk to the rearend guys. Is it possible for the rearend to have any vibration in it at a given RPM? I ask this because I have been trying to pen down a vibration problem on a 77 camaro I have. I know it's not a ls1 but I do own a 99TA.Can anyone tell if they have ever ran into this or know of anyone having this problem.Axles are good.Driveshaft good.it starts at 85mph,nothing until than.thanks for any help.

mine vibrates sometimes when it's idle a vibrating/huming sound comes from the rear

Mine vibrates at 140 mph, bad.