Differential

[Williys]

After pulling the axles on my 2003 Astro van which is 2 wheel drive, 6 cylinder auto. I was cleaning up the open rear end and cover when I noticed a roller bearing about 3/16 thick and approx. 1 1/4 long with rounded ends. I haven't found a detailed picture that shows this bearing or where it may have come from. I won't put it together until I find out. All help appreciated!!
Willys