Strange noise/feel after having the differential and transmission fluids changed on 2003 Mercedes-Benz SL500

After having the transmission , differential fluids changed/serivved and a ball joint replaced at 47000 miles, notice the car makes a strange "winding down" noise when lifting off the accelerator. Also notice the car seems to vibrate some and " idle rough". What could be the cause?

Asked by for the 2003 Mercedes-Benz SL500