bottom of differential?

So I purchased a 2000 XJ a while back and figured id replace the rear diff oil. Found these large pieces of metal sitting about the bottom. Can't quite figure what they are. nothings loose, no bad noises...any ideas?

 

Looks like pieces of a thrust washer, are your spider gears loose?

 

the gears seemed fine but you're probably correct with the washers. Am I able to replace those without removing the diff from the housing?

 

If it is the a thrust washer then yes they can be replaced without pulling the carrier. The trust washers sit behind the spider gears, to remove the spider gears you take out the center pin remove the c-clips and pull the axles out a little bit and the spider gears will basically fall out when you rotate them.