Diff fluid change, ok amount of metal?

[NWSierra]

I installed a banks diff on my 2020 GMC (gas), 28k miles.  I expected a little metal in the magnet.  May have been a little more than I expected?  
 

I bought it used with about 23k, I don’t pull often or heavy, but I think the prior owner had a fishing boat it pulled most of its use from the added airbags and trip log left in the ECU.

 

Any other things I should look at?  Makes me want to drain and fill the trans fluid three or four times if not flush if you can do these like the prior body style.  

[txab]

first change, looks fine. Amsoil 75w-90 and you're good to go

[Another JR]

As long as all the particles are very tiny, that seems normal  to me as well for 28k miles, but I’m not sure I’ve correctly understood the history you described.  

Edited August 29, 2022 by Another JR

[Z45]

Looks typical to me.  The manufacturing process and break in probably generated most of if, that's why they put them there to trap what's possibly left behind by the process to not cause it to fail under warranty.  Factory fill lubes are a comprise between quality and lowest cost.