DIFFERENTIAL: Fine Metal Dust in Old Oil

[CrazySte]

Hey Everyone,
last Week i went to a friend of mine shop and we replaced the Oil on the Front and Rear Differential as well as Transfer Case.

I bought this 2015 4Runner TRD-Pro from a Family Member last month, and in 60k miles he never changed the Differential Oil before, so i figured i go ahead and take care of it.

I switched all the Oils to

MOBIL 1 Full Synthetic 75-90

But here is the deal... as we were draining the Differential Oil, while the Front Differential was totally Clean, the Rear Differential looked practically Back and had some very fine Metal Dust in it.

No Shavings, there were not visible shavings in the Oil, but it looked really Dusty and Dark as it came out.

I was going to take a pic of it, but just in that moment i got a call from a Customer and my Friend went ahead in the meanwhile and dumped the exhausted Oil in the Recycling Tank.

Keeping in mind the Car has practically never been placed in 4WD, the Front Differential as well as the Trasnfer Case came out very clean... you could tell the Oil was Dark, but it was Clean, yet i wasn't too thrilled by the Dust in the Rear.


Not that i never seen it before, but it made me wonder:
has anyone else noticed Dust in their Differentials when doing the first Oil Change?

In any case, i was really happy there were no metal shavings mixed in the fluid.

Thank you for any info
CIAO

 

[Seymore Butts]

That's normal for the first change, especially at 60K. Did you clean the shavings off the magnetic plug?

 

[CrazySte]

That's normal for the first change, especially at 60K. Did you clean the shavings off the magnetic plug?

Obviously, blew it clean very well, but it looked there was a good quantity of dust that didn't get trapped by the magnet and was happily swishing around mixed in the Oil.

Anyway... No humming noise, drives perfectly smooth, i tried to turn tight tight in a parking lot both ways and all seems perfect.

So i guess i can stop worrying ;-)