So changed my diff oil and saw this

Thanks! The differential was okay though afterall?

 

Yes. My mechanic went through the entire thing afterwards for the gear swap. No issues.

 

I'm at 28K miles gonna do mine at 30K.

 

I'm at 51k now.
I did mine @ 500 for initial break in (tiny specs on magnet), again at 30k ( clean and clear of and metal debris), and will repeat every 30k. I've had mine from new but anytime I would purchase a used truck, the first thing I do is an every fluid change.