Annoying that probably Porsche knows whats wrong, but instead pretends that there is no issue at all

 

My 2017, built August 2016, still had the old style vent and they don't proactively do anything until the transfer case fails. They didn't have the fluid, so couldn't do a change for me when I was in for an oil change. I'm going to have it changed at the next interval. I don't know if anyone's had a failure after the latest vent change.

It doesn't sound like there was anything atypical about your driving conditions. Not that there should be any sensitivity! I don't think anyone here has pinned down anything specific about the causes, at least not that I've read here.

 

My transfer case had to be replaced on my 2012 Cayenne Turbo at about 60,000 miles.
In retrospect I noticed the beginning of the problem at around 47,000 miles while it was still under warranty.
It was a thumping sound made initially only at slow speeds when turning the steering wheel tight.
I thought it might be tire scrub or just an intermittent noise.
Since my nearest Porsche dealer was over 2 hours away, I blew off having it checked out.
It was a $4200 mistake as it was well out of warranty by the time the problem became obvious.

 

It's easy to not notice a failing transfer case at the onset so you're not alone. Initially the symptoms are non-specific and very intermittant where a few days and drives go by without any problem. I've found the symptoms seem more prominent once a number of miles have been done (on a given outing) thus heating up the case. Classically there is stumbling on moderate acceleration in gears 3 and 4 (as described here by others). It's similar to fuel starvation, fouled injectors or a bad miss in timing. If you're really sharp you can notice a rumble like going over a buckboard or rutted road when moving slow in reverse or 1st gear and with the steering hard over to one side. I've usually waited before bringing it in so as not to have to argue with the service advisor. If anyone is nearing the end of warranty or a 2 year warranted replacement don't wait. People here have asked about what would happen if the unit is not changed. I asked our SA and the only response I got was akin to 1930's motoring verbiage: "failure to proceed."

 

Submit your case to NTHSA - if Porsche will get off their butt and does a recall - you should get reimbursement.
https://www-odi.nhtsa.dot.gov/VehicleComplaint/
Make sure to say that failed transfer case could cause 4 wheel lockup and dangerous situation while driving.

 

One more point to help anyone trying to trouble shoot. On my receipt it states,"...unplugged the transfer case CU and test drove again and the jerking was gone." I'm not sure where the connection is or whether this throws a code but it seems like a clear diagnostic point being used by the dealer to determine a bad transfer case.

 

I posted to 6speed but will here as well.

You can add me to the list as well.
2012 Cayenne S
50,300 miles

Shudder not just on turns but once it started it was all the time. Around 2nd to 4th gear mainly. Diagnosed at dealership and replaced with the new design, new vent line and reprogrammed. Cost was paid for by Autonation 90 day used car warranty - thankfully!

A couple of notes-
1) The SA at Porsche West Houston has been there a long time and he is good. He noted that issue has been an overheating issue and that the new design has fixed it. We shall see but at least they are acknowledging and attempting to address it with a new design as many have seen. I asked why it hadn't been recalled and he sort of exhaled as this probably comes up every day. Unfortunately so far Porsche is claiming it is not a safety issue but just a quality of driving issue so they have yet to offer the recall. Who knows perhaps one day they will so I'd save my receipts just in case.

2) I corresponded with a super guy in Lithuania who claims these cases can likely be repaired. His company does all sorts of European transmissions and transfer cases. The items he noted that were typical fails were the clutch discs and the chain. He did make a point that we needed to verify the particular unit before proceeding. There are numbers on the bottom of the transfer case and from there he could identify whether his company could help. The two likely cases are the PL72ATC which is the active transfer case and the most common option and the other is a PL72T with a Torsen differential. The company name is AWD Tech. I have not used him but if my replacement was not covered I was going to try them out - assuming the fluid swap didn't help. He was very responsive and knowledgeable and if you have a good local transmission shop they should be able to break it down and replace with the AWD Tech parts if needed.

Has anyone tried to rebuilding one of these?

 

Also FWIW I just filed a complaint with the NHTSA. I'd recommend others do the same. It doesn't take long to file and while Porsche wants to say this is not a safety I argue otherwise. The car does not accelerate properly which is dangerous when merging with traffic.
My repair was paid for but I don't care. This should not be a customer pay $5k repair when it is a known engineering failure.

 

The two likely cases are the PL72ATC which is the active transfer case and the most common option and the other is a PL72T with a Torsen differential. The company name is AWD Tech.

Has anyone tried to rebuilding one of these?[/QUOTE]

I've had my case apart and took pictures at that time. When I look at the pictures I don't see any part numbers that correspond to your post. The closest I can come is a series of numbers 485 1122337MPTL. The case is a 95834101008 FYI. Where would you find the numbers you mention.
I may open mine up again if the stepper motor does not fix my problems. I should know by Friday COB. Thx

 

I posted the link to their website couple weeks ago https://awd.tech/collections/pl72-atc-vag?page=1

Looks like you will need about 500$ in parts to completely refresh the transfer case

 

I've had my case apart and took pictures at that time. When I look at the pictures I don't see any part numbers that correspond to your post. The closest I can come is a series of numbers 485 1122337MPTL. The case is a 95834101008 FYI. Where would you find the numbers you mention.
I may open mine up again if the stepper motor does not fix my problems. I should know by Friday COB. Thx[/QUOTE]

From awdtech site: This kit fits only if your number starting with 95834101

So their parts set is correct - https://awd.tech/collections/pl72-at...tc-bmw-porsche

What is the problem you experience?

 

If you have the actuator, perhaps that is what you are calling the stepper motor, then it is likely the ATC. As for the numbers I quoted you won't find those on the unit. The numbers I provided are the actual model of the transfer case from the manufacturer - not the Porsche numbers. There is a badge on the bottom of the unit with some numbers on it - etched below some raised text that says MADE IN AUSTRIA. If the numbers are still legible you can send those to AWD and they will let you know. The easiest way I corresponded with him was via Ebay but I can ask for a direct link. They do have a website as well but the Ebay messaging worked well. See pics below and the Ebay link for the clutch friction discs. He also has the chains.

https://www.ebay.com/itm/263086908030?ul_noapp=true





And here was one of his responses which explains some of the specifics:
-----------------------------------

Hello,

Nice to receive your question.

Let me answer in short with most important information.

1) 958th may be equipped with different transfer cases. The most significant differences you should find out - does it has actuator? If yes, this is PL72ATC - Active Transfer Case (the most common option). Otherwise - you have a PL72T transfer case with Torsen differential.
2) PL72ATC has 2 significant modification - 1" or 1.25" chain (width).
3) Useful diagrams: https://awd.tech/pages/pl72atc-diagram, https://awd.tech/pages/pl72t-diagram
4) Most common issues with PL72ATC are wear of clutch and stretching of chain. The PL72T's common fault is stretching of chain.

The symptoms you have described seems like worn-out clutch but I suggest to replace it together with chain if your t/c equipped with 1" one.
We have both the clutches and the chains listed here, but chains are currently out of stock until about 5th of January.
After rebuild of mechanics you should update software of transfer case ECU at the dealer or maybe at someone who has PIWIS. I mean exactly update of software, not adaptation procedure.

Also we can offer factory rebuilded transfer cases for much better price than it may be offered by dealer.

Regards,
Andrew

------------------------------------------


Again, I had mine replaced but there should be a better option for people that are not covered under warranty. I am hopeful this helps but if not it was at least worth a look.
Cheers-
Stephen

 

Thanks SCB71 will take a look.

 

Stephen,

Thanks for sharing. Great information.

Could you ask Andrew about the vents kits, what lubricant he puts in his re-manufactured units he sells direct to customers and any advice he has about increasing the longevity of our transfer cases.

 

It'd really be good to hear what's specifically leading to the failures of the automatic ones. We know the die and potentially moisture contaminating the fluid is a leading problem... but what else?