mdvigil

@lalawoo_chen I have two OEM end caps for sale if needed.

Brandon_911

Hi All,

First time poster. Just bought a 911 and I am having an issue with with my PDK transmission. My mechanic has let me know we are getting a few 17Dx error codes and they advised me it is likely the sensor. I searched this forum, but there's honestly so much to look at so just trying to get a direct response. My hope is that we can change the sensor and get the car back in working order. I was wondering if anyone has seen or used MLREng before for Porsche's? A few friends of mine have used them for their BMW SMG pumps and they seem pretty responsive and helpful. Not really looking for the best price, really looking for an honest transaction, reliability, good return policy and SUPPORT!!! Hope someone can guide me in the right direction as the wife and I are planning to bring the car down south for a road trip to escape the Canadian winters!!!

Link to product below if it helps:

https://mlreng.com/products/porsche-...40015040774231

Thanks Everyone!

t-design

Honestly, there is only one sensor on the market, with proven track records and installation history, and it's from T-Design. It will be also cheaper, even considering CAD rate.

Also, the 17Dx errors you mentioned are not very likely to be a distance sensor errors. Not unless you have other errors you didn't mentioned.

byroncheung

I haven’t seen much 17Dx from ppl having sensor problem, what does that even mean?

classic ones are 1731/2/3/4 - do you have those?

toddlamb

We haven't used that version, just T-design (with no issues).

What are your symptoms and actual codes?

toddlamb

Right now we have 4 PDK repairs in progress. I can't speak for other shops, but when done correctly the repair is not just the sensor replacement, but also wiring checks and diag, plus a LOT of extra time for programming when things are being stubborn. And yes the number of hours varies drastically depending on if the engine or trans needs to come out. 28 hours is the least amount of time for sensor replacement and wiring harness check, and 45 hours is the other end of the spectrum. For cars over 100k miles we generally recommend doing the full trans rebuild (clutches, bearings, etc) which gives the end result of a fresh transmission without the failure modes, still for much less than a Porsche factory replacement PDK.

And don't forget fluids and pan/gasket cost.

Expensive for sure, but I think it is reasonable given the amount of work and expertise involved, as well as the "cost savings" vs a new PDK.

Also for anyone reading thinking this is a common issue and concerned about buying a PDK car - this is still a VERY low failure rate. I wouldn't hesitate to buy a PDK car, but I would be sure to investigate possible issues on the car as we have had several recently come in that were bought at car auctions or from private car lots that turned out to have PDK issues shortly after purchase (seemed a little shady).

Brandon_911

Hey, thanks so much for responding so soon! I am going to check with my mechanic as they didn't give me much information other than the 17Dx errors and the fact that I needed to change the PDK sensor. I will definitely look into your unit!

Brandon_911

Hey, thanks so much for responding so soon! I am going to check with my mechanic as they didn't give me much information other than the 17Dx errors and the fact that I needed to change the PDK sensor. I will definitely look into your unit!

Brandon_911

I wish I knew! All I know is that my car is in limp mode and I get a gearbox fault on the dash. Update: after chatting with the guys at MLREng I am going to follow through with the purchase. Will update everyone on how it goes!

byroncheung

Really biggest challenge is to find a shop that's competent in doing the diagnosis and repair. I hope you have one already.

jjrichar

Over the last month I have done a tear down of a PDK from a Cayman GTS that was crashed at a track. The only things I haven't done is a complete disassembly of the gear set and removal of the pinion shaft, as these require some specialty tools I don't possess, and are places in the transmission where I think the average Porsche owner will not need a repair.

Whilst the transmission isn't the same as that from the 911 due to it being sort of a mirror image, the general configuration is the same, and so I'm confident someone working on one of these transmissions would have little difficulty after seeing what's inside a transmission from a Boxster/Cayman.

Firstly I'd like to thank PV997 for putting this thread together. It contains a lot of great information. It was very helpful, especially for the rear casing removal.

I did the tear down to satisfy my own curiosity, and also to try and help fill the void of information about these transmissions. Any workshop who has stripped one of these wants to keep the information to themselves for good reason. It's costly to attain. I did however want to get some information out there so the DIYer can have a pretty good crack at doing repairs. I also wanted to show workshops there is little to be scared of. The average auto transmission workshop would make light work of it in my opinion. They are very well designed and no more difficult than a normal auto. There are only a few tools you need and are simple to make yourself.

I've reached out to a number of businesses that provide aftermarket parts for the PDK and unfortunately didn't receive much response. Fortunately the performance department at Sonnex in the US showed interest in 'turning the needle' (as they described) with respect the PDK knowledge base. They know a lot more about auto transmissions than I ever will, and whatever input they can provide I'm sure will be very much appreciated. I've been sending them lots of component specs and photos so hopefully this will bear some fruit in the future. Getting aftermarket firms like this interested is essential in my opinion if Porsche insist on their policy of 'buy a new transmission' into the future.

I've attempted to provide as much information as possible so people feel comfortable with what is happening. Some of the videos are long for this reason. The valve body video is 40 mins for example, and is an edited video of about 100 individual clips.

Whilst I did the full tear down, below are some particulars that might interest people.

Valve body: Full teardown to individual valves with basic specs for all. Demonstrated how to test the solenoids.

Clutch pack: Removal/ replace and then fully cut open. Rebuilding looks pretty simple in my opinion from what I can see. There are 7DT70 clutch components available aftermarket from the searches I've done. The friction disks from the 7DT45 look to be identical, with the steels being thinner to get 6 disks installed rather than the 5 with the 7DT45.

Sealed bearing replacement. The two sealed bearings at the rear and one at the front won't last forever and will need replacing long term in my opinion. Rear seals are easy. Front seal needs pretty much a full disassembly to remove unfortunately. Specs of these seem to be bespoke for the transmission through NSK. One of those at the rear(inner input shaft) and the front bearing (outer input shaft) are the same spec. I've got some on order that may be a direct replacement for this and a possible alternative for the rear bearing that seems to be a special order for these transmissions only. The inner race on this one is thicker to have a smaller inner diameter to fit the rear of the output shaft.

I hate to be one of those 'self promoters' that pop up so regularly on forums, but this seemed to be the place where people go to get information and I thought it might help. I've done most of the project but there are still a few more things to do like a more in depth look at the electronics, which is where most transmission problems occur. I'll be putting more videos up as I gather more information. I'm fortunate to have the PDK on the bench in pieces, another in a fully working project car that is there just to learn on and another on my DD. Having the transmission on the bench as well as one next to it installed in a car so I can poke around, play with PIWIS etc has been a very good tool to learn from.

Links to videos I've made below:

Oil pan and filter

Clutch pack

Clutch pack teardown

Differential and driveshaft flanges

Pump and intermediate plate

Rear case removal

Gear set removal

Transmission cooling

Valve body

Gear set and shifter information

Pascoflyer

Mechanic appointment has come and gone. So here's my update:

I reset the transmission after the second failure, and it has been running fine ever since. Because there was no current issue on the car and the mechanic was backed up (very few people can work on them here) he asked me to come back if/when it breaks again. Let's hope it doesn't. I asked him if he could do repairs on the PDK and he said likely not but some sensors and things maybe.

More to come.... Well I hope not.

jbaker136

Fantastic videos! I have watched all the PDK ones and just used your interior ones this weekend. Thanks for the great support of the community.

Jeff

jjrichar

Happy you are getting something from them. Thanks for the donation. Much appreciated.

jjrichar

This is a message for PV997. I tried to send a PM but it's telling me you have too many messages stored and I can't send another. I'll need to put the message in public because of this. Send me a PM if you are interested in what I've discussed below.



Hello,

You may have noticed I've been tearing down a PDK and making a bunch of videos to try and expand the knowledge on the transmission.

You have done an outstanding job of creating this thread and keeping it up to date over the years, and there is clearly a lot of knowledge in your head that I'd like to tap into.

I have no interest in using your knowledge and taking credit. My only interest here is to open up the knowledge base as a whole and let the world know about it.

I'm in the fortunate position of having a stripped transmission with fully working electronics as well as another Boxster that is fully serviceable as a test bed. I bought this test car as a water damaged wreck to just strip down and learn from. As it turned out there was very little damage, and a few control units later it's a fully working car.

Whilst the mechanical stuff I'm pretty comfortable with, the electronics are where my limitations start. I have a basic level of knowledge, but not what is required to really open up what is going on, especially with the sensors. I'd really like to dig into the speed and distance sensors a little bit more. Recently I had PIWIS connected to the car and a serviceable distance sensor connected externally to the installed transmission to see the PIWIS response when I moved magnets along the sensor. I then connected that same sensor to a voltage source to see the response in isolation. I have a few resources that are helping me when they have time. The bloke who donated the PDK is an aerospace engineer, and is helping me when he has time. I don't know much about the speed sensor and is a project for the future. I reached out to Sonnex in the US. They responded and seemed keen to get involved, but time is always a limitation, especially when their possible market is relatively small.

Why do I want to dig into this? Whilst I commend businesses like T-design for coming up with aftermarket solutions, it seems to be priced based on it being the only available option. I'd like to get much more information out in the public arena about what is going on with the sensors/solenoids and the possible solutions. I could even see people fixing their own distance and speed sensors if the information was available.

If you are interested in an 'information collaboration', let me know. I have loads of time on my hands (I'm retired), and I'm very motivated to dig into this as far as I can go.

Thanks and all the best,
Jeff Richardson