Rear axle movement

[05liftedchevy]

So I have a 2005 chevy silverado 1500, my problem is my rear axle shafts have play in them. In and out. When they go in hard, they make a loud thud. Basically when I hit bumps or go over tracks, or if I do it myself by hand. Now I'm thinkin it's the C clips in there have worn down. Just want another opinion before I have to get in to my differential. Also the gear ratio is 3.42 if that helps with anything. Yes I absolutely hate it as well. Thanks in advance!

[Mr. Z71]

Not saying this is your problem, but I had an '81 GMC that if I grabbed the bed just above one of the rear wheels and did a push-pull back and forth, the rear end would knock and there was excessive movement of the truck from side to side. I drained the rear end only to find metal flakes in the fluid. Long story short, the carrier bearings were shot. I also had a bent axle shaft which I blame for trashing the bearings. Rebuilt the rear end, replaced the bent shaft and all was well.