So changed my 05 (2wd) differential fluid and found a couple of pieces of something that looks like some kind of clip or something.
Any ideas?

 

Looks to be a tracloc guide clip.

 

Living on borrowed time now if you have the stock limited slip lol. Google "Dodge Ram C clip failure". It's a misnomer, it's not the actual "C clip" that retains the axle itself but a piece from inside the differential.

 

Yep -, this is one of a few reasons I switched over to 3/4 ton and will never go back to 1/2 ton dodge. The larger issue is the piece that remains is now loose and likely grinding a groove in the axle housing that a machinist would be proud of.... I removed the remaining piece from mine so it wouldn't totally kill the axle housing.