Came across something while swapping out differential

[Flipzide]

I started taking apart my S13 differential yesterday to install my Kaaz 2 Way. After i removed the output shafts, i began to pull out the old oil seals. I tried using a screw driver to pull it out and when I looked inside, I found a circular spring.

I looked through a bunch of walkthroughs and even in my 1989-1990 FSM and I couldn't find anything in there about this piece.

Can anyone tell me what it's for? I bent it while trying to remove the seals when I wasn't looking inside the pumpkin. It was located between the seals and the side bearing adjustable washer.