Metal shavings and chunks in differential

[arazdolgin]

Changed axle seal gasket on drive axle today and found muddy oil. Opened differential plug to check oil and found metal shavings and small chunks on bottom plug. Rear gear are rebuilt in 2020 and changed oil in February this year. 4.10 rears heavy haul. No high temp, vibration or hard driving. Trying to get her slowly every time. However noticed some feeling on 1 speed etc. U joints greased every 5000 miles.

Some play on driveshaft near transmission, not sure if transmission yok bad or something. Can it be related to transmission? Tranny also was rebuilt couple years ago, but previous owner had perimeter trailer with very heavy loads like 200,000 lbs before me.

I did spin one time recently which damaged my tires a bit, protectors.

So I changed oil, cleaned out from previous shavings. Any thoughts? I cannot change rear every 2 years…
Some people say you can drive after cleaning and check if more chunks, if not, keep driving.

Maybe some good reliable shop you know, who can perform rebuild?