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I am contemplating doing an oil-only change (no pan and filter replacement) on my MY20 9Y0.1 S with 60k miles. Oil-only change is easy, pan drop is a bigger project.
I have read reports of people reusing the plastic 1/4 turn drain plug and o-ring. PCSS specifies single use for the drain plug. Generally across German brand cars, plastic drain plugs with o-ring are specified as single-use items.
I have not found a part number for the drain plug or a source for the plug + o-ring. Does anyone have suggestions?
Ordering a pan with drain plug, and using only the new plug, is an option but is wasteful and not what I am looking to do.
I am contemplating doing an oil-only change (no pan and filter replacement) on my MY20 9Y0.1 S with 60k miles. Oil-only change is easy, pan drop is a bigger project.
I have read reports of people reusing the plastic 1/4 turn drain plug and o-ring. PCSS specifies single use for the drain plug. Generally across German brand cars, plastic drain plugs with o-ring are specified as single-use items.
I have not found a part number for the drain plug or a source for the plug + o-ring. Does anyone have suggestions?
Ordering a pan with drain plug, and using only the new plug, is an option but is wasteful and not what I am looking to do.
Why dont you want to replace the entire pan? Does the instructions calls for sealants to be applied or is the pan plug and play with a built in gasket?
I spoke to my shop foreman on this, he says there is absolutely 0 value in doing transmission fluid under 100k miles.
ZF recommends 60k. Won’t hurt. Especially since you can’t get it all out. BMW says lifetime, which is probably not the best choice for long term owners. If you or your mechanic prefer somewhere in between, that is fine. I’ll use ZF’s recommendation.
I did the trans pan and fluid on our 2008 BMW 535xi at 90k miles and it is still doing fine 8 years later at 163k miles. Probably would have been fine even if not changed, but a rebuilt transmission is one of those expenses than can make keeping an old car no longer worthwhile. To me it is cheap insurance.
Driving conditions also make a difference. The car with heavy city use benefits from more frequent change intervals than the highway car. My cars see like heavy city use but I still stick to recommended intervals or less.
But the ATF isnt like the engine oil that is subject to contaminants of the air. I know trucks with transmissions over 300,000 miles still on factory fill.
You cannot do this transmission fluid on this car without a PIWIS tool. I wouldnt trust Autel like tool.
Looking for the easy way out! The "front axle support" aka K-brace needs to be removed and the pan itself + fasteners need to be replaced. Not rocket science just more time and cleanup to do the pan change.
Originally Posted by 3-Pedals
Does the instructions calls for sealants to be applied or is the pan plug and play with a built in gasket?
PCSS says to "replace the pan seal". Using PAB398009, the pan appeers to come with the "seal" (gasket) and new drain plug pre-installed in the new pan+filter assembly. I assume no wet sealant.
Originally Posted by 3-Pedals
I spoke to my shop foreman on this, he says there is absolutely 0 value in doing transmission fluid under 100k miles.
Everyone has an opinion!
I just found (it was available to me the entire time ) the part number for the stand-alone plug: PAB 398 008 B. I just ordered it for $24 from Delaware Porsche Parts. They had the lowest price, FCP doesn't offer them. When I get the part I will see if it is the right one - there were no photos only a parts diagram. If it is the wrong part it will get tossed. If it is the correct part I will do an oil-only change. PAB-398-008-B
XF recommends 60k. Won’t hurt. Especially since you can’t get it all out. BMW says lifetime, which is probably not the best choice for long term owners. If you or your mechanic prefer somewhere in between, that is fine. I’ll use ZF’s recommendation.
I did the trans pan and fluid on our 2008 BMW 535xi at 90k miles and it is still doing fine 8 years later at 163k miles. Probably would have been fine even if not changed, but a rebuilt transmission is one of those expenses than can make keeping an old car no longer worthwhile. To me it is cheap insurance.
Driving conditions also make a difference. The car with heavy city use benefits from more frequent change intervals than the highway car. My cars see like heavy city use but I still stick to recommended intervals or less.
Correct. ZF is the manufacturer in this case. Volkswagen is not.
On my 958-gen Touareg the Vdub dealer stated "sealed" for life for the 8-speed Aisin. Bollocks.
The ZF8HP is not sealed for life. The company who designed, tested and manufactured it specifies an OCI and provides parts to do so.
100% ignore words pronounced from any dealer or indy shop employee to the contrary on this topic.
The ZF transmissions use a bayonet style plug with a rubber gasket. I don't consider it one time use but if you feel the need to replace it, I see nothing wrong. I would strongly consider changing the entire pan if you could or at least doing multiple drain and fills to get most of the old fluid out. I used Ravenol 8HP which was desinged for the ZF transmissions and it's "fully synthectic" unlike the oem ZF8 which is "semi-synthetic".
Like @chassis, I’m considering doing the fluid-only change as well (@60k). While the transmissions are the same across many manufacturers, it is an extremely involved process on the Cayenne compared to the X5 and Range Rover, which were relatively simple (no cross bracing/exhaust to deal with). I spoke with ZF several years ago, who said it’s best to change between 50 and 60k miles. I’d rather do fluid-only than nothing at all. It shouldn’t be an issue to replace the plastic drain plug. I would check the O-ring to see if a little flat and replace if so.
Last edited by Poppyboy; Jun 19, 2025 at 06:57 PM.
My 2cents, dealer told me PDK on my 21 Panamera GTS needed PDK oil change @20,000 miles. Car was 4 years old. Can’t go wrong following Porsche schedule but this is ridiculous. My thinking is any time something is serviced, there is an opportunity to mess it up. So I’ll wait for 40,000 miles and keep the factory fluid a bit longer.
Like @chassis, I’m considering doing the fluid-only change as well (@60k). While the transmissions are the same across many manufacturers, it is an extremely involved process on the Cayenne compared to the X5 and Range Rover, which were relatively simple (no cross bracing/exhaust to deal with). I spoke with ZF several years ago, who said it’s best to change between 50 and 60k miles. I’d rather do fluid-only than nothing at all. It shouldn’t be an issue to replace the plastic drain plug. I would check the O-ring to see if a little flat and replace if so.
My inclination is that fluid only is fine, especially if you do fluid only the first time and the pan the second time and so on. The filter is pretty big and the little research I have done suggests they can last hundreds of thousands of miles. If you do the drain and fill twice or even 3 times, you do increase the percentage of new fluid. Have not done it yet on my 21 Cayenne S since it has only 46k so maybe next year. I have done the changes on a couple of other cars with ZF trans and bought replacement pans — aftermarket brand and it was not that much extra work to replace the pan. Have not decided yet about the pan for the Cayenne, but I will probably go ahead and change it since I am confident I can remove whatever parts are in the way and an aftermarket pan usually does not cost very much.
I ordered drain plug PAB 398 008 B. Part number from partslink24 for MY20 9Y0.1 ZF8HP using my VIN.
Looks like the right part. I will remove the bellypan and compare it with the actual drain plug. If it looks OK I will do an oil drain and refill, no pan/filter replacement, using the new drain plug.
If it turns out the part I ordered is not the right one, and I discover this after the oil is drained from the transmission, I will simply reuse the old plug and see what happens. The plug is specified as single use and PCSS calls for replacing the pan/filter/plug assembly.
The o-ring is pretty slender so it makes sense the plug + o-ring are specified as single use.
Please let us know as soon as you implement your plan, @chassis. I’m getting ready to do an engine oil and filter change, and figured I would do the trans fluid at the same time. I plan to follow the same procedure as on other makes: Initial fill, shift through gears, bring to temperature (86-120 F) based on OBD scanner, final fill with engine running.
Pedigree of the part I ordered: my VIN --> partslink24 --> part number --> Porsche Delaware --> my hands.
We will see if it fits.
Plan A: use the new plug + new o-ring after I drain the old oil
Plan B: use the old plug + new o-ring if the o-rings are interchangeable
Plan C: reuse the old plug + old o-ring
Overall the job is pretty easy from an access point of view. I removed half of the transmission bellypan screws and was able to see the drain and fill plugs. No crossmembers to remove.
Drain plug, fill plug and 8mm hex bit test-fitted
Factory drain plug - not the same as the plug I ordered using a Porsche part number from a Porsche dealer using my VIN on partslink24.
New plug fitted against the factory plug, not a great photo.
ZFH8P drain plug - available individually?
The "front axle support" aka K-brace needs to be removed and the pan itself + fasteners need to be replaced. Not rocket science just more time and cleanup to do the pan change.
) the part number for the stand-alone plug: PAB 398 008 B. I just ordered it for $24 from Delaware Porsche Parts. They had the lowest price, FCP doesn't offer them. When I get the part I will see if it is the right one - there were no photos only a parts diagram. If it is the wrong part it will get tossed. If it is the correct part I will do an oil-only change. PAB-398-008-B
