Tiny bits in diff. fluid cause for worry???

Just changed the oil in my front/rear diffs and the rear diff. had quite a bit of the sludge. But when I wiped it on a shop towel I found two tiny (very small) black bits that were big enough to feel with my finger and I saw some metallic flecks when I looked at it in the sun. NOTE: My 2018 Runner has 83,400 miles and this is the first diff. oil change to my knowledge (I bought it at 79k, it was a lease).

How concerned should I be? I know the sludge is normal, but the bits (although pretty small) and flecks kind of worry me.

 

Change it again after 10k and re-evaluate the situation

 

Worthless without pics.

 

Yeah, shoulda taken a pic, but they were very small, somewhat larger than a grain of sand.

 

I little bit of metallic debris can be normal, especially if it's the first change.

Any pics?

Edit, NM, I just saw post #4

 

It’s fine.

 

Grain of sand?

Keep on driving don't bother changing it at another 10k.

 

Yeah, I'm probably overthinking it -- definitely bigger than a single grain of sand, just big enough to feel it when you run your finger across it and it's clearly visible as a little black bit that's not the grey sludge

 

You are fine.


EDIT- wait,.. no, its bad, like real bad. Please email me with a "totaled title" cash offer, and ill try my best to take it off your hands. I will use it as a donor vehicle for my 2018. Thank you.