I had a new rear differential put in last month after I toasted my original doing some rather stupid stunt driving around my neighbourhood.

It's been well over 1000 miles since it's been put in, so I decided to change the fluid that the dealer filled it with for Amsoil's 80W90 GL5 Gear Oil.

To my dismay, when I ripped opened the drain plug, the fluid came out silvery grey!!  And the magnet on the plug was sludged with grains of metal filings.

Nothing seems out of the ordinary as far as noise or performance goes...could this be a result of the initial break in period since it was put in or is this the early warning sign of something about to go ary in the not to distant future?

That is not normal, the gears are eating themselves up,
I would take it back and have it fixed before it goes out
and you get stuck somewhere

Wild

Thanks for the reply, I have since checked and changed the fluid twice after driving some 620 miles and the metal shavings have drastically reduced, in fact the last time it was pretty clean and the magnet on the drain plug was pretty clean as well.

Again, I'm not hearing any abnormal noises, certainly not like it was doing after I fucked it up.   I am going to continue driving over the course of the next 30 days or so and recheck it again.  I have a lot of driving to do so it will be a good test to see what's happening.  Luckily for me I have a 1 year warranty on the parts and labour.

Checked it again yesterday and there were no metal filings!  I am quite relieved.