Sorry to hear that. The cases can be found from various on-line Porsche dealers for right around $3k. Shipping might cost something though..

Let us know how it works out changing the oil. So far we're batting 1,000.. be nice to keep the streak going.

 

Suncoast and Sonnen are always cheaper than all other dealerships. Wonder what their cost will be. Will check tomorrow.

 

You might want to double check that the replacements are the latest revision level whatever that currently is.

 

They just confirmed my 2016 Cayenne GTS with 18K needs a new transfer case....

It had all the symptoms listed in this thread. The Porsche tech said 'yep, transfer case' 20 seconds into the ride I was taking him on...

 

I guess since it's under warranty they are offering to simply replace the case. Seems a rather expensive way to get the oil changed.. but if Porsche is paying..

 

So much for latest version and improvements!

 

Is there anything known on what most likely precipitates the failure?

As in, what driving behaviors put the kind of stress on it that causes it to fail prematurely?

Having had several 4WD and AWD vehicles in the past I'm familiar with avoiding things like engaging low ratios on dry pavement. But what else is involved here?

And do the folks who have had failures also have PTV or any other drive train options?

 

Nope. Not that we know. But no one has taken apart a failed transfer case either.I don't think that's an issue - since the failures are uniformly spread across all the gasoline engine models - with HP/torque varying by 2:1 between the V6 and the V8-Twin Turbo.There is no low ratio. I have no idea how many people have selected the off-road mode of the vehicle, that might have some effect.. see my next post about that.Nope. PTV is actually rather rare and there aren't any other drive train options I know of.

As long as no one has opened a case up, and Porsche isn't talking.. the actual cause of the failures will remain as guesswork, but I'll address that in the next post.

 

A strong recommendation to anyone with a Cayenne:

Make a transfer-case (TC) oil change a regular maintenance item. I'd suggest every 30,000 miles, and checking the oil every oil change when the car is up on the lift.

Doing a TC oil change on a lift will add about 10 minutes to the time spent changing the engine oil. Perhaps less. The TC drain and fill plugs are RIGHT THERE IN YOUR FACE - you actually could touch both of them with your nose if you were so inclined. Nothing in the way, lots of access, nothing has to be removed. I'll add a photo taken from underneath when I have a chance.. but there is no reason to not change the oil.

So far - over on RennTech - we have 4 people who were experiencing TC symptoms - told by Porsche they needed new TC's - who have changed their oil and no longer are experiencing ANY symptoms. We have one person who changed their TC oil and his symptoms were reduced but not eliminated - but - he didn't use a recommended oil, or even an oil that the oil manufacturer suggested for the use. He is going to change it again using one of the recommended oils.

My own experience: My '11 Twin-Turbo didn't exhibit the symptoms other people had. The common symptom is a roughness in accelerating and some popping/clicking noises from under the car. Mine had a tiny bit of unevenness on acceleration - but not so much that I thought it abnormal. I have 72,300 miles on the CTT.

I changed the oil today - putting in the new part# Porsche oil. It was available from SunsetPorscheParts.com - they had the best price (around $45 + shipping.) Local dealer wanted $75 for it.

I did it on a lift since I have a friendly independent who was interested. It took longer to set the lift up to lift the Cayenne then it did to change the oil.

What drained out was black. It had a slight burned odor to it, but not really strong. It didn't smell like gear oil, or the oil that was going in. It seemed rather thin. There was no sign of water contamination. I've saved a sample to send to Blackstone to analyze.

As to what causes the oil breakdown - I suspect several items: One is heat. There is a small deflector right under the TC that is there to direct air up over the case and cool it. There has to be a reason for that deflector. I wonder if failures happen more often in warmer climates? The other may simply be use. The design is such that the clutch is ALWAYS partly engaged - and always slipping. That's how power is transferred from the rear to the front or rear to front. If someone drives in situations where they do a lot of turning - that will cause more slippage of the clutch as the ratio of front/rear torque changes. If someone has partly worn tires on one axle - that will cause continual slippage as the system adjusts the difference in rotation speed of the tires. ALL of these situations do two things - wear the clutch - and heat up the transfer case. Excessive heat is certainly indicated on TC's where people have reported a burned smell in the old oil.

The new oil had the usual gear-oil sort of smell (sulphur) and was a light golden color. Took about 2 minutes to pump it full and button it up.

This could EASILY be done on one with air-suspension by simply going to the highest suspension position and sliding under the vehicle on a piece of cardboard.

The result surprised me. It felt different backing out of his parking lot. After about 2 miles it felt much different. The acceleration is absolutely smooth now. It sort of encourages me to put my foot in the pedal..

So - why is this?

I believe the oil has broken down due to heat, and is contaminated with clutch wear particles. The clutch in the TC is a multiplate wet clutch. That means that the oil used IS important for smooth operation. Oil that is too thin and contaminated with wear particles will cause uneven clutch operation.

It's my belief that the roughness in acceleration (and on turning) and the noise are symptoms of the clutch plates engaging erratically, sticking and then releasing.

New oil seems to cure this - at least in the vehicles it's been tried in. People have gotten success using other than the expensive Porsche oil. An oil from Ravenol has been used successfully - and claims to meet the Porsche specification for the oil.

Car manufacturers like extended service intervals.. for a simple reason, it makes it easier to sell cars. People are afraid of high maintenance costs, (which would be very true if this was done by Porsche - the estimate to change the oil was over $200..) so the manufacturer extends the service intervals as far as they possibly can and have the car survive the original warranty period and any CPO period they might have to cover. At 100,000 miles - to the manufacturer - the car is basically dead to them. They have no continuing interest since they aren't going to make money off it.

So - it's easy and inexpensive to do - and it has FIXED issues that Porsche dealers wanted $4,000 to fix.

Just do it. Change your TC oil. And to check the oil at oil change intervals - remove the top fill plug and stick your finger in (or if it's full and warm some oil will run out) if the oil is DARK - replace it.

YMMV - but bet not a whole lot..

Looking forward from under the car:

 

These are the two best points.

One, nothing like that gets added to a vehicle without a risks that would end up costing the manufacturer. A flange, shield, deflector, whatever, costs money. No vendor would spend money on anything like that in the vehicle if it didn't have a cost associated with NOT doing it. As in, premature failure of something or risk of injury.

The second point could almost be said at any point after taking delivery.

Certainly once it's out of warranty, and potentially after if a negligent defect warranting recall is found (GM ignitions, etc). Brand loyalty is certainly something to value but it's definitely in the manufacturer's interest to find ways to encourage new vehicle sales, not parts and service. Planned obsolescence, as they say.

Good advice on the transfer case oil changes.

I'd wonder, though, some folks have seen cases failing at unusually low mileage numbers. It'd certainly be worth extracting some oil for testing in those situations. That'd at least show if it was a contamination issue. But it wouldn't necessarily show why.

I wonder what, if any, programming is involved with transfer cases? Could there be something being done wrong "by the computer" that's causing excessive clutch wear? Traction control depends on a lot of factors and I'd imagine eventually something controls the transfer case.

 

My wife's 2013 CTT with roughly ~36k miles it getting the transfer case replaced as we speak. Surging during acceleration and noise at slow sharp turns. Covered under the CPO.

 

Thanks. It seems a no-brainer. It's cheap and easy to do, so why not do it?True. I have a sample for Blackstone of mine - but without other samples, and preferably a virgin oil sample to check it against - whatever they tell me will be of limited value since they don't have a normal baseline. I'd also love to know what the "oil wear" factor stored in the All-Wheel-Drive computer is for the ones that were replaced.The transfer case is programmed to the vehicle - or the controller - I haven't looked to see where that lives. I do know I could read out a lot of information from the transfer case controller - including the build date, the VIN# and a bunch of other stuff. I'll try doing it again perhaps tomorrow and do a report on the readout.

What was interesting was I tried to reset the oil-service information for the TC using my iCarScan tool (which can easily read it..) It tried to write to it, but it came back with a message it was unable to. I'm not certain yet what to make of that - or if it even has any significance to the vehicle. I'm just so delighted with how it's driving now that I haven't bothered thinking about it..

UPDATE: Figured out that the engine had to be off to reset the mileage - which then resets the oil wear indicator. Duh. Can't do it with the engine running. Just did it and my scan tool worked fine.

I think there is a calibration automatically done by the stepper motor to the clutch pack. My scan tool could report the number of successful and unsuccessful calibrations. There were something like 10 unsuccessful, and about 750 successful calibrations. I imagine it might be something like putting the stepper into continuous travel locking the clutch until the motor on it stalled - and setting that step position as the calibration point. But - that's just a guess on my part.

In chatting with my mechanic friend (who is also an engineer) we talked about why use kWh as a measurement of wear, and how that number might be determined. His thinking since kWh is an energy measurement and you could determine the amount of heat energy total that the oil has been exposed to (the TC has a temperature sensor, I can read it with my tool, and the computer could quite obviously know the running hours). The more heat energy total the oil is exposed to the more worn it is going to be. Something like spinning a wheel for a period of time, or doing donuts is likely to spike the temperature - increasing the kWh quickly (and causing fast wear/damage to the oil.) That would also be a good reason that the counter (oil date) should be able to be reset and cleared. I'll have to hook up my Durametric and see if it has any capabilities there.

My thinking on the oil change Porsche made - might be that they spec'd an oil with a higher "ash" point (temperature where the oil starts to break down and actually "burn".) If so - the friction/viscosity characteristics are likely the same as the old oil - it will just retain those characteristics longer. Again - guesswork on my part.

I'm waiting to hear from a number of people on RennTech about their experience with a new oil. I'll try to remember to come back here with the info when we get it.

 

To try to gather a little info here - that may or may not be useful, IF you've experienced a TC failure, please reply to this thread with the following info. After giving that info, any comments or summary of warranty/non-warranty, fix was replaced or just oil change is also welcome.

Info needed (and please try to keep this order

Year, Model, Mileage, Location, ForumUserName
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I think it should be pretty obvious what's asked for.. and will be interested in what the responses are. If we get enough I'll start putting it together in a spreadsheet to see if there are any common factors.

An example response would be:

2011, CTT, 72,300, New Jersey USA, deilenberger

(Except mine didn't fail..)

TIA!

 

2011, CTT, 67,700 Pennsylvania USA, TJtheDJ

 

2012 CTT, 105k miles, VA (mostly), now KY. Sybco