Hi everyone,
Yesterday one of my friends told me that my rear wheels were moving a little side to side. This morning, I jacked up the rear end of my truck trying to diagnose the problem. As I said in the title, the wheel hub moves in and out BUT not side to side and there is no sound coming from the rear end while I'm driving. I take the drum out and I figured out that the shaft was 1/4 inch out... (Dust on the shaft and then a nice grey finish that were in the diff I suppose...)

And I know that it's normal a little gap for the c-clip.