Fr3nch

This is concerning a 991.1 C4S, but I figured Id ask here since the AWD system is the same as the 997 Turbo.

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. Car has about 20k miles on it.


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 to the point where its dark-grey opaque. For comparison, the transmission/rear diff fluid (same type of oil) turned a clear 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?

IXXI TT

I replaced all fluids on 997.2 turbo at 60k and this is what the front diff looked like



I plan on doing 60k intervals for these types of fluids.

Fr3nch

Looks like it’s pretty normal then. Can’t tell you how much a relief your photo is. Thanks for the reply.

IXXI TT

I bet! Had to dig it up from 2018. I knew I took a pic because it seems odd to have that much shavings. Guessing it is from the manufacturing process without a "1200 mile" initial flush.

Here's the plug cleaned for comparison, world of difference.

Ruskiy

My S2000 rear LSD has that much metal after every 20K flush for 200k miles. She’s still fine.

kpl

mine looked the same too

Johnny DB

Mine definitely had some but not as much as pictured...