Last month durring tech, they shook the rear of my car and thought maybe a wheel was alittle loose because of a noise we heard, but was aloud to run after checking all corners. Today while chasing a brake noise, I pulled on my right rear wheel and i can hear the axle moving. Not enough to see it move, but enough to hear and feel it. The left is not as bad in comparison. how much should I worry about it? and how hard of a job is it? Does the diff. and gears have to come out to change the C-clips, or can it be done easly with just the rear cover removed?