J. Patterson

I have a B8.5 S5 with 6speed manual trans and Sport Diff.
In reading the 2015 Audi maintenance schedule I see that it calls for fluid and lube service on these units at 55k miles but for "RS5 and RS7 only".

"Rear Sport Differential – change ATF for clutch hydraulics and differential oil l RS 5 and RS 7 only"

Why would the S5 be different than the RS5? Anyone know?
I'm only at 19k miles now but planning ahead :-)

https://www.audiusa.com/content/dam/...-Year-2015.pdf

superswiss

It's actually 35/75/115k miles, 55/115/175 km. The units are tuned differently in the RS5, more aggressive. I suspect that in the RS5, the clutches engage much more often than in the S5. The higher strung DSG in the RS5 also calls for more fluid changes. Perhaps Quattro Gmbh also assumes that RS5s are driven harder than their siblings. What you have to keep in mind is that the RS5 is not made by Audi, it's made by Quattro Gmbh, so the recommended maintenance is what Quattro Gmbh recommends, whereas for the S5 it's what Audi recommends.

J. Patterson

Thanks. I was too superficial in reading. RS5 Sport Diff IS scheduled for service at 35/75/115k miles. I do wonder if the service requirement might not be more relevant to use that to which engine is in the car though. ( If I track mine I will plan to service the diff at 40k or so intervals.)

findalex

They are probably different "sport differentials".

There is a 0BE rear axel drive/sport differential which handles up to 1000 Nm
There is a 0BF which handles up to 700 Nm

This is from the A8, but I would think something similar applies to the S5 and RS5.

Here are the instructions on how to change the gear oil.

Here is how you change the ATF on the sport differential.

Glisse

S5 has slightly more torque than RS5. Think Superswiss' comments re. duty cycle / quattro GmbH (now Audi Sport) presuming RS5 may be driven harder / track days, etc, are the reason.

Using the correct fluid and ensuring the seal integrity is maintained is probably more an issue than changing it is. I have never heard of a clutch failure in the sport diff, but maybe it can happen.

theclutch

THANKS for the links to the instructions! Would you happen to know what the torque settings are? And also, what oil do we use for the sport differential?

Ape Factory

I have a full writeup myself on the rear differential and transmission for the RS5 and the S5 is going to be very similar. I would double check the fluid numbers with Audi directly in case there are differences between the RS5 and S5 fluid for the rear differential. Here's a link to fluids and a how-to: https://www.audizine.com/forum/showt...r-differential).

theclutch

You are THE man! Thank you!

J. Patterson

findalex

I would change the fluids a little sooner if you want to keep your car for a while. I have a A5 with an open rear differential and it's supposed to be "lifetime". Well, let me tell you, when I drained the fluids at 65K, it was dark! Much darker than the new fluid I replaced it with.