e30rapidic

Curious - does anyone know what is actually failing in the transfer cases? Or are there a few different types of failure? I know Porsche is quiet on them but I'd like to tear one apart to inspect and rebuild.

Thankfully, I have/had no issues with the TC in my '13 GTS...so no reason to tear it open. ;-)

deilenberger

It would be interesting to open a failed one up. It appears there are two different "failures" - similar symptoms, but perhaps different causes. Keep in mind this is all speculation/guesswork on my part. I am not Porsche or the TC manufacturer, and I haven't had one open.

Early death failures - appear to be a binding clutch pack. This leads to a jerky shift in lower gears under power. The fix by Porsche is to replace the TC. This seems to happen at mileages less than 30,000 miles.
Later life slippage - the symptoms are of a slipping clutch pack - this leads to a brief increase in RPM not matched by an increase in speed as a shift is occurring, followed by a lurch when the clutch finally engages. This seems to happen at mileages > 50,000 miles. These symptoms can range from very mild (almost unnoticeable) to really annoying.

In both cases - the clutch pack appears to be where the problem is. In the first case probably simply a defective clutch. In the second case - a slipping clutch, perhaps caused by contaminated/worn transfer case fluid. The first case a fluid change does nothing. The second case - so far fluid changes have fixed a LOT of them, and the fix seems long lasting (reports of over 10,000 miles on the new fluid and the problem hasn't repeated.) Porsche addresses the 2nd case with a modified TC vent (the standard one is right on top of the TC, up in the transmission tunnel area. Sounds good until you realize there is an air-cooling scoop under the TC that going through water - will throw the water on the front driveshaft - and then right up at the vent) and a change in their fluid.

In either case - Porsche just replaces the cases. And takes the old ones back - so finding one to take apart would involve finding a wreck or something..

e30rapidic

Thanks for the detailed reply! Seems like water/oil emulsion is a main cause? To me that would lead to the clutch packs binding/slipping/jerking and causing chain stretch.

I've rebuilt cutch packs before so if I could ever get my hands on a failed TC for cheap, i'd tackle it. I did the fluid change in mine at 60,000 miles to be preventative, so hopefully ill be okay.

I'm amazed at how little information is out there as to whats going on inside these things. Especially since the issue has been around a long time.

Kirill

Big read on TC: https://www.renntech.org/forums/topi...er-case-fluid/

deilenberger

There are no parts available for these cases. I found one listing for a chain - but it turned out it was for a 955 transfer case. There may be a seal or bearing available from Porsche - but other than that - they expect it to go back to the manufacturer who may just reuse the case and put all new guts into it. As far as water/oil emulsion being the main cause - maybe - although people who've collected samples of the oil coming out of their cases haven't reported this. They reported the oil looking somewhat thinner than the new oil, and typically black in color (new is amber) and sometimes having a burnt smell. Certainly water getting into the case won't do a multiplate clutch assembly any good - rust forming on the plates will play havoc with it engaging smoothly.

The other thread covers it pretty comprehensively - I don't think we need to repeat all that once again here.. If there are any questions - they'd be better asked in that thread so all the info stays together.

trendy996

Maybe make a dry water filter to fit over the vent like aem does on their intakes.

deilenberger

Not knowing who AEM is - I can't say, but.. the vent is at the very top of the transfer case. The only way to access it is to drop the transfer case down or removing it. Porsche now installs a high mounted vent "kit" on the new ones they put in - the vent runs from the same fitting on the TC up to some plumbing that opens up on the top of the engine compartment firewall. If it was possible to retrofit this without TC removal I suspect a lot of us would have already done it.

2011cayenneS

Phaff in Vaughan told me to use a Ford, moisture removal fluid, they have it at the Porsche dealer,
they do a 1 litre swap out the transfer case fluid, add the Ford additive, top up with Porsche fluid, good to go, $360 later.

Service manager told me this 3 days ago.

mines going in next week, mines not hesitating/chugging/studdering like ive heard the symptoms can be, but I don’t ever want it to start.


cheers

deilenberger

Not knowing who "Phaff in Vaughan" is - I can't contact them and ask about the Ford part#.. think you can do this whilst you're in getting it done? That might be useful info to have for those of us (most of us) with the original style vent.

Kirill

Wouldn't replacement of fluid get rid of "water" anyway?

I remember there is some Ford Friction Modifier thing that supposed to work magic on differentials - may be this is what they mean -

2011cayenneS

Sorry Deilenberger, phaff is my local Porsche dealer
The service manager told me they stock a few cases of the product,
“it will have an ingredient that binds to moisture and stops/prevents transfer case shutter” (I was told)
“If vehicle is still under cpo warranty they cannot use the Ford fluid (non Porsche product) and entire case is swapped out, if out of cpo $360 and problem solved”

Pfaff Porsche
105 Four Valley Drive
Vaughan, Ontario L4K 4V8Service Department

Phone : 888.538.6572

deilenberger

Since you're the guy getting it done, and in touch with the dealer - think you could ask for a few more details about it? I tried Google - and it came up with nothing based on my searches. I'm sure it's out there somewhere.. but where?

2011cayenneS

oh I’ll be that guy, definitely will document the experience I F’ing love going to that dealer, beautiful cars, woman and free espresso , it’s the little things in life.

99% positive it is the Ford Friction Modifier tha the t kiril dude above replied.

I just bought my Cayenne, came with factory 22”s, I asked dealer to swap for new 20’s and new tires (my last A4 had 2” over size wheels, drove harsh and ate tires, leaks or cut side walls bimonthly) while in service I pushed for new brakes and rotors, and a rear number repaint, it had some cargo removing surface scratches that we an eyesore.

So........Its still at the dealer,
i was so ......pumped/testosterone overrun during the purchase, that I only took three pictures with my iPhone, two are fuzzy and one has terrible lighting, like I took them with my eyes closed.
I look forward to uploading more photos once resprayed/detailed and I drive it outta there, it’s still surreal.

CarGuyNVA

"transfer case - what actually fails?'

Most likely your wallet if you're not under warranty!

In my case, fortunately both were covered (yes, I did say "BOTH"). Hopefully the most recent one will be the last, since they used all the latest revised components and newly added ones (like the vent kit).

I have 3.5 years more of extended warranty, then I'm probably vehicle shopping again.

e30rapidic

Cayenne case overhaul "only thing I can find wrong is...this chain...is stretched..."
https://www.youtube.com/watch?v=kcYRshldlZc&feature=youtu.be&t=18s

For my own edification.....and the fact that I feel like i'm about to add my name to the transfer case issue......

Today, when letting my foot of the brake, I got a nice jerk before hitting the accelerator (I'm convinced the jerking is from chain stretch). Slight flutter under light acceleration too now.

I'm thinking that I can get her in the air with the wheels hanging, twist one of the driveshafts and see how much free rotation there is.


And for anyone else reading this; after a bunch of google searches and youtube videos, it seems like the Mercedes SUV owners have the same fiasco. I found these videos to illustrate how much the chain stretches in those.

Mercedes Benz (in the backyard!)

BMW

Russian bloke rebuilding a Cayenne (955/957??) transfer case

Time to find a replacement chain...and go back to my mechanic days. If something comes of this, i'll add my notes/findings to the main transfer case link.


Chains; which one for a 2013 GTS? https://awd.tech/collections/types?constraint=porsche-cayenne&q=Chains