I am in need of new wheel bearings for a 2010 e550 coupe and was wondering if anyone knows the procedure for this. The new ones I received have a small thin inner ring that sits inside the rubber ring that touches the back of the spindle. The ones I removed did not have this ring and were probably there from factory. And when I try to place this ring on it will not fit on the spindle. I am wondering what this ring is for and if I need it or not.