My car is approaching 160k miles and the service manual says to change the tranny fluid at 160k miles, but in the BMW world I've heard plenty of stories about transmissions messing up after a fluid change. I've also read a few threads where the same thing happened with cayennes.

It seems the general consensus is to either replacing it every ~50k, or just not touch it. Another thing is how the transmission has to be at operating temp or something to get the right fill.

I was thinking maybe I can compromise and just extract exactly one quart, and put in 1 fresh quart. And maybe repeat every few months. Is this just a horrible idea? I'd really like to put fresh fluid in but fear what may happen and I think just one quart here and there may help prolong the life without shocking it with all fresh fluid. Kinda like a fish tank lol

 

Despite what the service interval advises, the transmission oil change is well overdue at 160k miles.
Change it all now and then every 50k miles.

 

This makes no sense, the idea is to get all new fluid in there, by swaping out a quart at a time it will never be clean fluid. And you are correct about the fluid, about things happening after you change it. On alot of high end vehicles BMW Range rover and so on they use the ZC tranny. If you look at the lable it says that its a sealed transmission meaning the fluid is good for the life of the vehicle. On a Range Rover Sport for example since I owned one changing the transmission fluid and filter means changing the whole pan out since the filter is built into the pan, not a cheap process. I changed it because It was at the right interval? Again several thoughts on this like I said life of the vehicle, but there are reports of slpping etc and then after the change it went away.

Also you will see some companies offering to purge the transmission with a machine that blows in hot chemicals to clean the tranmission out avoiding having to drop the pan. This is my opinion take it or leave it, I'm not a fan of this because I dont like the detergents used, and the process seems a bit envasive.

Is your Transmission acting up? slipping etc? you know the old line IF AINT BROKE etc

If you do plan on changing it use only Porsche OEM products this will get your best results

 

You should not wait until 160k miles to change the ATF. I dropped my pan at 90k miles (04 CTT). There are six magnets. They were all covered in fine dark metal sludge (shavings) along with the bottom of the pan and the filter. The fluid was a couple shades darker than it should have been. Purple instead of wine red. I cleaned up the pan and magnets.

The transmission is supposed to be cold for draining and initial fill (2-3 quarts). Then you need to start it and get it warm when adding the remaining fluid to top it off. The thermostat opens at 40 celcius or 104 Fahrenheit. I found that I could not get much more into the transmission after it warmed up. I ended up using 7 quarts including at least half a quart of spilled fluid.

There are instructions available on the web. ECSTuning has them posted with their kit. I didn't buy their kit but used their instructions which are slightly more coherent than the Porsche manual although they don't include removal of the transmission pan shield. It takes a bit of time to warm the transmission. 10 minutes should be enough. I had a thermocouple.

I bought the fluid, filter, seals (2) from Pelican Parts. I didn't need the nine quarts they sold me. I measured what came out (about 6) and made sure at least that much went in (6+).

By the way it shifts much smoother on light throttle. We had a nice cold snap and my wife said there was a noticeable difference on cold start. I also ran it very hard to confirm it is still performing as it should in all gears at all speeds.

 

So, you don't change your oil unless your engine acts up? Transmission too? Not wise advice to give. Change everything within suggested limits, or sooner, and you'll sleep better.

 

WOW!!! so you read my whole post and only took that one line out of it all??? EVER HEARD OF SARCASM??? was making a joke my friend that was not advice.. I said nothing about not changing your oil. Way to assume there buddy. His post was about swaping in a quart at a time. OF COURSE you follow the guidelines of every vehicle I never said not. Not sure why your attacking my post, have you read what HE wanted to do? AND I DID POST if you plan on swaping fluid use porsche only fluid why dont you redirect your attack on somone else....... And man your advice is so much better change everything within suggested limits??? you sound like an owners manual try re-reading the post before attacking the whole purpose was to tell him not change it one quart at a time man

 

Sorry, I didn't know you were sensitive. There was no attack. Simply, your top information was sound but, your bottom information was flawed. Did I misquote you?

 

Sensitive?? Really? C'mon man you jumped all over a statement that was supposed to be sarcastic so yeah I would say misquoted btw did you look how old this post was? June of last year and he hasn't posted since so why even comment?

 

I commented on your post. If you're wondering why you responded to his old post... then you should ask yourself. Either way, bad advice (sarcastic or not) is bad advice. If you don't like your post to be quoted to you... don't post it. However, have a great weekend, I think I'll go skiing.

 

Hahaahah WOW I responded to his post?? Uhh no your post of knocking me, you started this not me... Have a great weekend yourself PAL. Think I'll go snowboarding

 

If you want to attack people, please go somewhere else.

 

OK. Now that the pissing match is done, bottom line is change fluid now and continue to change every 50-70K. Period.
There are other posts discussing which fluids, how often, etc.

 

I have been trying to find which ATfluid people are using, but no dice. What did you guys use?

 

There are many threads. Not home to give links now. Look up atf fluid and you will find.
Many use Toyota atf IV. Many use redline. Many use OEM fluid. Biggest difference is price.

 

Toyota fluid users.....think their fluid is same quality as Porsche but cheaper.

Redline users.....think their fluid is better than Porsche but cheaper.