[perrypeckslip]

I have a strange humming or vibration on my 1999 Durango when I get above 45mph. I had front tires, shocks, brakes and rotors replaced- still there. My son thinks it is coming from the rear when he rides in the back- can the rear-end be bad or low on fluid? Visually the driveshaft and ball joints look fine- can a driveshaft get unbalanced? Any suggestions would be appreciated- thanks !