PV997

Thanks Kuro. Muddtt sent me the housing and I'll install my PWB, program the sensors, pot it, and then mail it to jjrichar. He's going to install it in a PDK for a fit and functional checks, in addition to an operational test.

Note that the ABS housing material is not suitable for a final product, however it did allow us to quickly and cheaply produce a test article. We are looking into the feasibility of printing this using high temperature filaments and it's not a crazy idea. The ZF speed sensor is in a comparable environment and it's made of high temp glass-reinforced nylon (PA46 GF30) via injection molding. That being said, CNC machined aluminum is also affordable in moderate quantities (i.e. 20-50 units).

After we get more info I'll compile a detailed parts list and costs, it's blowing my mind how simple and inexpensive this is ending up. It's infuriating that Porsche embargoes these, provides zero documentation, and forced people to buy a new/remanufactured transmission when they fail.

Noting that this project really is a testament to crowd sourcing and a big thank you to the open-source movement in general.

Pascoflyer

PDK Update:

Background: Bought my 997.2 PDK about 2 months ago now. Two transmission emergency run errors within two weeks. Codes were P1990 and P1991. Reset the transmission's memory with the Aircon thing, ran fine for a while. Took to a mechanic, he said bring it back when it's broken. I have extended warranty (Japanese company) That covers the drivetrain and a few extras. Does not cover some sensors.

After 2 months or so of daily driving, it starts to show more issues.

It showed 2nd gear on my dash but was clearly in neutral. Corrected and we were GTG. A few weeks later, It started doing the same thing that happened with the original emergency run, but this time no emergency run message. That is- shifted up and down kind of randomly, but was in neutral. Gauges showed gears 2, 4, then nothing. Screen was black and would not go into reverse. More neutral. Turned it off, back on. Still broken. Off and back on again, and its running fine.

Symptoms seem to be really consistent with @sandwedge 's experience.

Not sure if my warranty will cover whatever's wrong with it and also not sure if there's anything wrong with it.

Side note, overall the transmission seems to perform poorly. Feels like the clutch is slipping. Sometimes jarring upshifts into second with steady throttle application. Often jarring downshifts into 1st. Usually I just leave it in paddle mode because it's so unpleasant otherwise. 43k miles.

toddlamb

I can’t speak for your specific warranty but we currently have a third party warranty that is covering an entire PDK rebuild for a customer. So I’d suggest digging into the details a bit.

Pascoflyer

I appreciate the response! It's encouraging, I hope that holds true for me as well! The language barrier can make these kinds of details really difficult to understand, well at least until the bill comes.

Kuro Neko

Feel free to ping me if either language or garage help needed.
As although you may need to get your car to Honshu, once there, there are a number of mission specialists who can help...
Reasonably priced too.
大丈夫！

Pascoflyer

Thank you! I will keep that in mind! My wife helps with language but, she doesn't know cars and the process is very stressful for her. Here's hoping I don't need ship it anywhere lol. Would be a good excuse to drive it around my favorite honshu roads on pickup though hehehe.

Kuro Neko

Ha!
I just posted on that similarly: https://rennlist.com/forums/987-foru...l#post18538764
Sounds like you could perhaps drive it there now, via the ferry, at least before the PDK goes totally to silicon heaven...

Pascoflyer

Love your thread and your photography. I'm a photographer/Videographer by trade so I really enjoy your posts!

PV997

Do you still have the P1990 and P1991 faults with the newest issues? P1990 is a software fault and P1991 is a CAN bus fault, both of these are usually caused by the Transmission Control Unit (TCU), not the PDK transmission itself. The transmission doesn't have any software and it's not on the CAN bus, but both do apply to the TCU. The TCU is inside the car and is relatively easy to access if it's actually causing the problem.

The shifting issues you mention sound like a bad PDK calibration, perhaps linked to the software issues. It doesn't sound like a hard transmission failure to me but it's impossible to say for certain. If those same errors are back I'd start troubleshooting with the TCU.

Pascoflyer

That makes a lot of sense.

I need to get another code reader on it, I borrowed my neighbors and have since moved.

Would a new TCU be the first step or something like a TCU tune?

PV997

I personally do not like throwing parts at a problem, particularly expensive ones like a TCU ($900). Plus a new TCU will need to be configured using a PIWIS and won't work right out of the box.

My approach would be to troubleshoot it using the diagnostic capabilities of a PIWIS first (I have a PIWIS clone). Not just reading the codes, but using the real time data features to monitor what the TCU is reading from the PDK and what it thinks it's sending to the ECM. From that I'd look for indications that support or contradict the TCU hypothesis.

Without a PIWIS I'd look for someone who has one first (Porsche dealer, good independent mechanic, local Porsche nut) as you are likely going to need one regardless. Even if you do want to gamble and install a new TCU you will need a PIWIS to configure it and calibrate the PDK afterwards.

toma nova

Although I did not DIY (the focus of this thread), my PDK is now as good as new!

I towed the Boxster to Atlanta Speedwerks in October and they replaced the distance sensor while I worked remotely from quaint Gainesville, GA. Repair went well, 80 mile drive testing all modes and possibilities was good, ready to trailer back to Houston…

During the cold drive the next morning, the tech heard bearing noise while pulling out of the shop. (Previous day’s drives were all warm / hot after calibrating the PDK.) So, we towed home an empty trailer and put the trans on the list for a rebuild.

All new internals (bearings, solenoids, valve body, clutches, etc.) and I’ve now got a new PDK. Todd helped me out a bunch on the labor so I essentially paid for just the rebuild plus the new distance sensor. Although an expensive repair, I’ve now got a complete rebuild with the lifetime sensor from Vlad. I’m happy with the work and recommend Atlanta Speedwerks for any PDK repairs (they had two more out of cars for rebuilds when I was picking up). I’ve not had one other repair or issue with the car in 7 years, 30k miles, and 20+ track days.

Thanks for all the knowledge in this thread (and linked), I was very informed going into the repair.

donR

I was wondering how many of these PDK problems are due to infrequent PDK oil service? Or is it just plain bad luck and does it make not much difference? I notice Porsche recommended transmission service is few and far between if not at all. Whereas my Independent workshop recommends PDK oil service after 10 or so track days. Can't remember the exact number but I've been aiming for every 18months or so as it is not a cheap service due to the integrated filter in the Cayman. However, hopefully it is cheap insurance!

jjrichar

If a sensor failure it's not going to be due to the lack of fluid change. Clutch wear/failure and general poor shifting/performance, I definitely think fluid changes are going to help.

I think the general consensus as time has progressed is that more often than what Porsche recommend is going to be a good thing. It also depends on the usage like you have mentioned.

Me personally I change the PDK fluid every 10,000km. Overkill for street use, but it's dead easy to drain and refill, and I've always preferred to over service all my cars. The car only gets about 5000km a year, so this is every two years. 30 mins of my time and about $30 of fluid. You can normally drain about 2.5 - 3L of fluid (a bit over 5L total), so you never get to fully replace it all. Hence changing regularly keeps the quality of fluid pretty good. Keeping the fluid clean and the oil/additive quality high is what is important in my opinion.

Regarding the filter/pan change, this really increases the workload/cost significantly and in my opinion it serves little purpose. It's the drain of the fluid that removes most of the debris in the fluid, as it's just very fine clutch dust that isn't caught by the filter and continues to circulate. Ferrous material from the clutch steel disks is caught by the pan magnets. The filter catches only large stuff, and is designed to last a long, long time, unlike an engine oil filter. I plan to change the pan at 200,000km. Many workshops recommend changing pan/filter change much more often. I don't think it's required. I used to replace filters all the time, but after opening them and finding them clean I don't bother until well into the life of the transmission.

On the transmission I pulled apart I did a bit of an experiment when I dropped the pan. The oil was dirty as you would expect, and so the filter also looked dirty, which initially makes you think the filter needs replacing. I put the pan on its side to allow all the oil to drain from the filter for two weeks and then inspected. The filter medium at the filter entrance now looked close to new and not dirty at all. I took photos and zoomed in to the point of easily seeing the fibres of the filter. Of note the fibre structure is very open compared to that of an engine oil filter. Any debris? Zero. I couldn't find anything. By comparison, if you do this on an engine oil filter after being removed the captured debris is easily seen with the naked eye.

This is the same experience I've had with all autos I've worked on that have an identical filter setup as the PDK. The only difference is the oil in a normal auto is supporting many more clutches and also the gear sets and torque converter. I've still found filters to be devoid of any debris once the dirty oil has been allowed to fully drain. The PDK fluid supports two clutches and a few bearings by way of comparison.

Regarding the gear oil, I change at the same interval. This is again a case of complete overkill, but the car is in the air so I just do it. Another $30 of fluid every two years. Unlike the PDK fluid where you will only be able to drain a bit more than 50% of the fluid, for the gear section you can drain nearly the entire amount, a little under 3L. For street use I personally think every 50,000 km would be ample.

PV997

He didn't mention it himself so I'll do it for him. @jjrichar is the guy who figured out you don't need a PIWIS to change PDK clutch fluid and documented it in detail here.

https://www.planet-9.com/threads/diy...l-mode.237865/

Before I got to know him I tested this myself using his method then repeated the fill procedure using my PIWIS clone. The level was exactly the same, no difference.

People should reconsider paying a dealership to do this (unless you have a really good relationship) as they will likely put the screws to you in both labor and fluid costs. There was a thread over in the Turbo forum where not only did they charge him $45 a liter (more than double Sunset's price at the time), but they also charged him for 6 liters (the dry fill quantity) when only 3 liters comes out in a normal change. They will also likely want to replace the pan/filter whether it's needed or not. If you do go this route please get an itemized estimate up front and caveat emptor.