Fr3nch

Car is a 2014 C4S with about 20k miles. I replaced the fluid in my front differential as part of some trouble-shooting Im doing for a weird smell. Detailed here if youre interested

I was pretty shocked to pull the drain plug and see so much metal. The fluid itself as a lot of metal in it too. It looks like the original light honey color, but with grey metal particles suspended in it. For comparison, the transmission/rear diff fluid (same type of oil) turned a dark honey color. Like amber-ish. Almost no metal on that plug.

Ive changed a lot of 30k mile diff fluid in my day, never on a Porsche, and its never looked like this.

Is this a normal thing? How can Porsche claim this is 120k mile fluid with this much metal in it at 20k?

LexVan

You could send the diff/trans fluid to Blackstone Labs for an UOA.

asellus

Did you pull the diff drain plug or the mag clutch drain plug?

That's an alarming amount of wear if it's the diff oil for 20k.

911-TOUR

If thats the diff oil plug, that just ain't right. I'd send for a UOA as Lex suggests and then go from there depending on what metals come back.

Fr3nch

Yep. The Blackstone analysis is part of this. Sending in the samples tomorrow.

This is really a bummer. I love this car.

GONEIN10

if it's stuck to a magnetic plug I'm guessing it's metal, no need for an analysis to confirm that.

asellus

yeah I'm confused as to what people hope to gain from a UOA, honestly.

it's metal from gear-on-gear. maybe clutch material. it's kind of what a differential does. the amount is what's concerning, not the type.

Guards_Red_991

That's not a lot, it is actually fine. Here's an example of what a lot looks like:

A418t81

Not a lot and normal especially if this is first fluid change.

ClassJ

Looks normal. I would run it until there is a problem. Maybe increase oil change frequency,

Jack F

Where did this plug come from? It wearing an 80s silver spike wig.

Guards_Red_991

Land Rover Discovery: 80k abusive miles running on 33" Mud Terrains, we were never nice to the car. It ran for another 100k miles with no issues.

My intention with the photo is to convey to the OP that his is normal. No need to be worried at all.

AdamSanta85

I was going to say same, that doesn’t look bad to me. It’s not like chunks or slivers/flakes. I’ve seen a lot worse on cars with diffs with no issues.

The car comes with a magnetic drain plug stock because they expect it to collect stuff.

My diff plug on my trucks or Subaru’s always looked like that

JRBucks

That would not concern me in the least, especially considering it is the first change. But an analysis won't hurt.

G.I.G.

Not with my 911, but to add some context since gears are gears for the most part....

I changed the gear oil in my rear diff on my '07 4Runner at 30K miles. My magnetic drain plug looked just like yours. Oddly, Toyota didn't even call for a gear oil change in the diffs at that interval (I think it calls for 60k miles on the diffs) so I was glad I changed it when I did and have been following a 30K mile gear oil change regimen on my diffs since. My 4Runner now has 180K miles with the original gears (rear diff, center diff/transfer case, and front diff) with no signs of impending failure.

New gears in differentials typically require 500 miles for break-in, then a gear oil change. I've always been perplexed why the same isn't true for new differentials coming directly from the factory. Regardless, most manufactures don't recommend a gear oil change anytime soon after purchase so I'm assuming they're not concerned with some wear as the gears seat together properly.

I wouldn't be at all concerned with what you saw. Wipe it off, replace the washer, reinstall and fill with a quality gear oil according to Porsche factory specs, and drive. I doubt you'll have any problems with your front diff anytime soon.