2007 Jeep Grand Cherokee Limited 4dr SUV 4WD (4.7L 8cyl 5A)
We have had the vehicle to the dealer 3 times for the same problem....vibration in the driveline. Enough vibration that the vehicle in the rear view mirror looks like it has six headlights. Dealer has replaced both driveshafts and then turned them 180 deg. This was a fruitless effort, however it did improve some but the 180 flip put it back to its previous high vibration.
Navigation and Sirius Radio
Reengineer the driveline. The Service Mgr told me the ends are now CV Joints and not U-Joints.