Let's figure it out what fluids should be add for total trans maintenance:

Based on my searching in PET 8.2 and PCSS:

Trans PDK main
OEM #00004321044 4L
Drain plug #PAF009390 x2
Didn't see oil filter in this build

Front differential
OEM #00004330472 350ML (PCSS says)
Drain plug, not sure about PN#

Front transfer case
OEM #00004330563 700ML
+ flushing 1.7L (PCSS says)
Drain Plug, not sure about PN#

Rear differential
OEM #00004330472
didn't find capacity
Not sure about the drain plug, maybe PAF009389 ???
Please tell your experience and tricks.

 

You might need piwis3 for the transmission service…?

how many kilometres do you have on the car that your servicing this already?

 

sure I have the original piwis for servicing trans

I change all the fluids every 20,000 due to harsh driving

 

After a fluid change, does a clutch relearn need to be done? I’ll look it up.

please update this thread, good info here.

 

you can do trans relearn, but PCSS doesn't say you need it after changing ATF

 

Where can I purchase the Piwis? Thanks in advance

 

Did you figure out your issue?
From what I've found, rear diff (called pdk gear wheel set) is around 5L of oil.