Rattling Sound From Rear and Highway Vibration

[KerryBoehm]

This is on a 2007 GMC Yukon XLT 1500 4WD with about 130K miles. Noticed this last weekend while on a longish highway trip last weekend. At 75 mph there is an annoying vibration seemingly coming from the rear of the vehicle. At 80 it mostly goes away.

This weekend I rotated the tires to see if the vibration moves to the front and afterwards drove around on side streets a bit with the windows down. Got some looks being temps are in the 20's here. Anyway, I notice often when accelerating from a dead stop I hear a loud tapping sound up to about 20mph.

I'm suspecting differential, U joints, or transfer case. Anyone have any suggestions?

 

[petethepug]

If it’s at the rear, you’re right, u joints, diff or loose lugs on a rim. Rear of these vehicles usually pretty uneventful.