The purpose of the thread is to discuss technically and professionally the correct use of a Dual Clutch (PDK - Porsche Doppelkupplungsgetriebe) - in order to understand whether the use we make of a PDK is proper and can it be a cause of failure?

As we all know, improper use of a manual transmission can inevitably lead to failure (in synchronizations, a "slips" clutch and in uncommon cases a rebuild...).
Moreover, as we all know, PDK with is a manual gearbox for everything with automatic control. It is completely different from a torque converter transmission system which is a fully automatic and built "for hard days"..

PDK is very expensive and in the near future none of us will have a warranty.. It also made me think about how to use PDK and that is one of the reasons for writing this thread

Some facts about PDK that I consider important to note:

Sport and Sport Plus Mode in PDK - These modes fundamentally change the map of the PDK (a more aggressive map and probably more load on the PDK).
I estimate that Sport and Sport+ may lead to a warming of the PDK. Thoughts..

In addition, remember that I read in a car book that it is not recommended to activate the Sport Plus mode and especially "Launch Control" - until the car temperature does not reach a normal temperature (meaning engine temperature and oil temperature / oil pressure).
My common sense tells me that it is recommended to switch to manual mode / turn on Sport and Sport Plus mode only after the vehicle has warmed up properly.

Do you think that incorrect use of PDK may affect the longevity of our PDK?

Feel free to develop the thread in any direction you want (also for racing use).

General points for thought, I found this link interesting:
https://www.quora.com/What-are-some-...ansmission-car

 

Sports Plus is okay even when cold provided you are in manual mode. Auto mode will hold higher RPMs, but you control shifts in manual mode to keep RPMs in range.

I honestly think driving in Sports Plus Auto mode would be miserable on public streets as it will keep RPMs up to high, but I have never driven any of my 911 pdks in auto mode for more than maybe 5 seconds when I accidentally forget to put in manual mode in the 10 years I have been driving 911s with pdks.

I would also think manual mode in Sports Plus is better for the transmission than auto mode in either normal or Sport as the transmission is doing a whole lot more shifting in auto mode.

I candidly feel throttle response and driving experience in anything but Sports Plus manual mode is boring and very unsatisfying. The car is so easy to shift with paddles on the steering wheel where at least one hand has to be no matter what you are doing, I really don’t understand why anyone would drivie a pdk in boring, family truckster feel auto mode.

 

The above is limited to public streets. If on race track, Sports Plus auto mode will run your best lap times regardless how great you think your manual shifting points are. The pdk is pretty much perfect on track in Sports Plus auto mode.

I also do not think wearing is an issue with pdk in Sports Plus mode. Mechanically, these transmissions are brutally tough and less slippage in gear changes might even be more preferable. The pdk is doing much less work and much less shifting in manual mode and less slippage and more crisp shifts may not be a negative for the pdk, especially just cruising around and not doing red line shifts all the time, which I pretty much do. I abuse the heck out of mine on and off track and NO ISSUES.

I think the only manual shift I would avoid is the Sports Plus manual shift from 2nd to 1st. Let the pdk make that one itself.

RE: Launch Mode

Have not used that in 3 or 4 years when I first got my 991.2 Turbo. Have not used it once in my 2012 GTS. I do agree that will cause wear on the pdk and a 997.2 is not a drag strip car anyway.

 

I spent a lot of time researching PDK failures. I found a correlation to temperature in early units, but that was fixed in 2011(?) by increased cooling. Other than that, I found nothing conclusive, other than most failures are electronic. It's damn hard to predict when or how electronic failures occur. The only mechanical failure that I have found that occurs with any frequency is a pin inside the transmission breaks off that tells when the transmission is in reverse, which affects backup camera and side mirrors lowering. I believe some enterprising owners figured out how to use an external switch to perform the same function, to avoid having to pay for a replacement transmission. There was one other known issue with the crimping of a connector on a wire on the outside of the PDK. Porsche put out a kit to fix this problem, but it didn't always work.

 

Doug H is correct. Additionally: According to Porsche Launch control doesn’t cause abnormal PDK wear and is considered a normal operation. Cold engine and transmission cause wear and a lot of tear, regardless of mode. Launch control is “gee whiz” and not practical for 99.99% of us drivers, excepting race starts. Sport Plus works perfectly on the track for almost every corner you will encounter, with a rare manual intervention. As a side note, Porsche Track Experience will put 90 launches on a Turbo S in one day and they’ve not replaced a single PDK on a Turbo S. Try to match that ruggedness with any other super car.

 

Isn't the line pressure increased when in Sport (and Sport+) modes? Wouldn't more hydraulic pressure = more wear on the pump, etc ?

 

Interesting

1. I also allow PDK to shift gear from 2nd gear to 1st gear automatically.
2. I am usually in manual mode. However, in traffic jams I found the D mode (no sport mode) - the PDK works much smoother and less bouncy.
3. Usually, I switch to manual mode only after the "oil temperature" reaches 90 degrees.
I do not know why but it seems to me that it is healthier for the PDK. Of course in a situation like this I find myself in 7th gear at 50 mph. But apparently there is a justification for this and it causes the PDK to go through a quick lubrication.
It reminds me of the theory that says it is not recommended to "warm up an engine" before starting driving. It is recommended to start the engine and drive straight (try not to exceed 3,000 RPM until the engine warms up).

 

According to the Porsche owner's manual (Pg 77 for my '09) - "When starting the engine, be ready to drive immediately. Drive the vehicle at moderate speeds and avoid engine speeds above 4,200 RPM during the first 5 minutes."

 

I think that hard track use or use in high heat climates can cause early wear/failure. However, what does seem to be common is not mechanical failures with PDK, but sensor failures inside of the PDK. I owned a 997.2 C2S in PDK which I didn't have issues with, but I do have an Audi S4 which has a dual clutch transmission. That car saw very light driving use, was not driven hard, almost all highway use, it was used in Ohio, so not exactly a hot climate, if anything it's ridiculously cold for 6 months of the year, cool to warm for 4 months and warm to hot for 2 months. That transmission failed and was replaced. 78k miles. Fluid changes at recommended intervals of 35k miles and 75k miles. I think it's more random on when these transmissions fail.

 

What are the variables that contribute to premature PDK failure? The true answer(s) to that are a holy grail for PDK owners. Particulars of use? Climate factors? Maintenance approaches?

I think the idea behind this thread is a good one. Anytime that PDK owners can compare notes so to speak and share factual information, it can only lead to a better collective understanding of this transmission and what to anticipate / expect from it.

Drawing conclusions based on hearsay and opinions (easy to do), won't serve to advance the cause to better understand the PDK.

In the absence of much of any factual information directly from Porsche, most of what we are doing is just guessing - and that is ok I think. Doing that will serve to provide a realm of "dots" that perhaps can be connected over time to provide a clearer factual picture of the nature of this transmission.

Launch Control
Use of Launch Control - while some opinions may be that this car was engineered and built to endure such usage, through common sense, we absolutely know that it pushes the hardware more to the limits. Porsche says this in the owner's manual about Launch Control - "Caution! Stress on components increases dramatically when starting with maximum acceleration in comparison with normal driving off. Use of Launch Control will inevitably reduce the life of the engaged engine and transmission components." (Text shown with bold highlights are not my transcription edits - they appear as such in the owner's manual.)

Whose idea at Porsche was to provide Launch Control as a feature on the production 911? An engineer? Maybe a marketer?

PDK Fluids
Porsche says this: "Fluids / oils have to be checked and changed at the intervals listed in your Maintenance Schedule. The transmission may be damaged by even a tiny speck of dirt, only a clean funnel or spout must be used when adding fluid / oil."

We read or hear anecdotally about PDK failures but never really know the variables that contributed to each of those individual failures. In the absence of the facts, it's easy to just point to the transmission itself as the culprit.

Hopefully this thread will continue to live and can serve as a journal of facts that help piece together the real PDK failure story.

 

Subscribed.
I am a little different than many of the other PDK owners here. I drive my car mostly in automatic mode but in Sport. I almost never drive it in Normal mode because it lugs horribly. The exception is when I have dicey streets with speed bumps, potholes, lots of stopping and other stop and start obstacles. I will run it in Normal mode then because the higher gearing allows better coasting without the jarring engine braking effects. I do sometimes drive in manual but it's rare because I don't like the up/down paddles that came stock. I will upgrade the wheel at some point and then maybe a lot more manual shifting. I also don't like winding up the revs with no load on the engine, so I don't drive around in 2nd at 5K just to hear it...

I put the car in Sport immediately for almost all driving including warming up the car. I have found if you drive it easy, the shift points keep revs between 2k and 3k which is perfect. The last thing I will say is that despite the automatic mode, the PDK is still a clutched transmission and I always think of it that way when driving it. I try to work with it rather than just hammer away. The shifting logic is always trying to predict whether you are going to upshift or downshift. It's always looking at braking, lateral g forces, steering angles, accelerator pedal, etc.. I try to drive it in the way it expects. Less drama. That doesn't always work as you know, crap can happen to force a quick change of plans...

 

It is telling when one person says Porsche says launch control is normal and just fine, and another quotes the manual as clearly implying it is hard on the hardware. Common sense would be it is not good at all. Maybe a salesman would encourage it. I don't know if sport plus causes more or less wear with faster shifts. If I guessed, I would think it was slightly more wear. Maybe only ZF knows, since it is their transmission.

 

If you want to save fuel costs, don’t you use less right pedal? Want your tires to last 25,000 miles? Don’t drive hard. If you want to conserve the clutch pack don’t get silly with LC use and use more mellow auto modes. No one who’s posted here does anything with the PDK not allowed by the owner manual. All technique stuff.

Any hard, high rev, high torque launch, regardless whether it’s a manual, Tip or PDK is always harder on the equipment. The Porsche manual blurb is likely nothing but a caution for newbs that think a jackrabbit burnout at every light is cool. The bottom line is LC causes increased wear for any vehicle. Warranties expire and don’t cover excessive wear due to “abusive” driving. It would suck to break the PDK a year after the warranty period ‘cuz you or the PO liked to use the car as a dragster.

OP asks if improper techniques using the PDK can cause failure. Sure! Ironman88 nailed it. Read your Owner’s Manual. Talk to your Porsche techs. Drive and maintain the car and it’s systems properly. If you track the car, you need to do more frequent service and replacement than for DD duties. I’m not aware of any better dual clutch system than the PDK, be it performance, reliability or quirks.

The 997 line has many millions of miles on PDK. Lots of arcane information and data to be shared. Clutch pack life would be interesting data, the golden nugget, to discover.

 

Thanks Bro

Everything has a reason, sometimes, the difficulty is finding the reason.
As we all know, even in manual transmissions (bulletproof), there is always the friend who breaks the transmission and changes clutch frequently or shifts gears incorrectly and breaks the transmission.

Driving style, climate and maintenance affect the longevity of the transmission..

For maintenance, this is an interesting topic -
I was at a Porsche dealership and asked about the PDK (I inquired about fluid replacement). I was told at Porsche that sometimes, after replacing a clutch/gear fluid - the problems with PDK started..
Has anyone else heard of this?
Suggests checking with the Porsche dealership and updating us..
Personally, from my inquiry, I found 4 different Porsche recommendations regarding the timing of fluid replacement in PDK.

 

The sensors and electronics in the PDK certainly seem to be the failure cause, and not the hardware itself, which seems to have very few or even zero failures. I've heard of one case of PDK failure with metal shavings in the tenasmission, which was likely a hardware failure, but who knows, maybe it was a sensor failure that then allowed damage to occur to the hardware.

But, until those sensors inside the PDK can be replaced, instead of the entire transmission, it doesn't really matter whether it's an electronic or mechanical failure, as the rectification procedure is the same - complete transmission replacement, with a high price tag. Those internal proximity sensors are probably not much different than a simple hall sensor or camshaft or crackshaft position sensor. Those fail too, but are easy to simply replace. I've had to replace one on my 997 and both the crankshaft and camshaft position sensors on my daughter's X5 at about 100k miles.

For me, since I keep my cars forever and work on them myself, until the PDK can be repaired and not replaced, I won't own one, irregardless of how impressive they are to drive. It won't be long before 997.2 cars are also too old to qualify for an aftermarket warranty or the costs of one will be the equivalent of buying a PDK every 3-4 years anyway, and not much else on the 997.2 seems to fail (rear taillights and center reflector strips leaking in moisture, LCAs if they're even covered and not considered a wear item, HPFP, etc), so for the most part, that warranty money being paid is really insurance against a PDK failure.

I'm also of the opinion that engines and transmissions need to be fully up to operating temperature before being driven hard. Hammering on a motor or transmission before that occurs certainly contributes to wear and premature failure.

This will be my only comment in this thread since I'll now be attacked by you know who for contribiting in a PDK thread. 👍