Chunks in Diff. Fluid Bad???

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 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 and flecks kind of worry me.

 

It is not drivable. Please send a "totaled title, wrecked condition" offer, and i will take it off your hands. As said in the other thread. Im just here to help. It will make a great donor vehicle for my 2018 that i will keep until i die, and die again. Thank you for your time.

Edit- I will even come to you, and drive it home. Wait, i mean, get it off your lot. Thank you again for your time.

 

Very concerned. Too truly know what damage there is, it will have to be taken apart. Find a good shop. Sounds like the previous owner did something bad to it and then dumped the vehicle. Also, the sludge is not normal. My 92 has never had sludge in the diff. I have only replace the fluid twice in 30 years.

 

Yeah no already covered.

https://www.4runners.com/threads/tiny-bits-in-diff-fluid-cause-for-worry.31578/#post-449137

 

Didn't see that. "grains of sand". He made it sound like they were much bigger.

 

Thanks guys -- yeah, I put the size between larger than a grain of sand, but smaller than half a grain of rice. From what I've been able to find since I posted, shouldn't be an issue since this is the first diff. oil change and so far (knock on wood) I haven't noticed any weird noises or anything else.