SAN997

Today I set about to change my transmission oil. Even though Porsche claims it is "lifetime fluid", I rather doubt it will be good for another 50+ years on top of the 10 years it has already been in there. In fact, when I drained it out, it was fairly dark and there was a fair bit of gunk and metal particles collected in the drain plug.

Anyway, I ordered exactly 3.0L of Porsche transmission fluid from the Porsche dealership. I asked the parts guy if 3.0L will be enough, given that the manual asks for 2.9L, "fill until it overflows". Well, he assured me that 3.0L is enough...

Sure enough, after putting the entire 3.0L in, and even using a turkey baster to get the last 50mL, it is just below the bottom of the filling plug. I stuck a little wire in the fill hole, and confirmed that it is within a few mm of the bottom.

Nevertheless, I'm not doing this again for another 10+ years, and the whole point of doing this myself and ordering the Porsche fluid was to do the job right.

I confirmed per the service manual and online DIY that I am filling in the correct hole (the lower one that is on the Passenger's side near the front), so this is not my problem. Also, the car is reasonably level to the extent I can do so in my garage and on my jack stands.

Question: do you think it is critical that I fill until it overflows? Should I try to beg for another 200 mL from Porsche? I don't want to find out in 10 or 15 years that this was a mistake.

lurchphil

Well done! 3 liters is perfect. Your car may actually shift better with the new fluid. Mine did.

hpapad01

From what you are describing you should be good to go. Technically there should be just 11mm lower from the bottom edge of the filling hole so you should be perfect.

However, I do have a question for you. Did you replace the crash gaskets? There are called sealing ring made out of aluminum. The part number is 99730180800. According to a friend (Porsche Mechanic) both should be changed.

SAN997

Yes, I always replace the sealing rings. We have a place in San Diego called Murphy's Industrial Hardware that literally sells every part known to man. They have every metric and standard size of copper and aluminum sealing ring in 1 or 2mm size steps. They have an entire aisle of drill bits, end mills and about 100 foot two sided aisle just of nails and screws.

I call it heaven