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About me: Hello all, my name is Damien Law, you address me as Damien. As someone who fixes transmission(DSG MOSTLY) for a living, I always like to try new solutions.
THIS DIY: This post will be about replacing displacement sensor on Porsche 987 mated to a PDK gearbox, using new sensor made by T-Design (http://t-design9.com/porsche_PDK_dis...on_sensor.html).
The procedure is mostly the same for all variations of PDK on 997, 991, 987 and and 981 models. The sensor is not available from Porsche at all, but the new unit is manufactured by T-Design. This repair saves car owner from replacing the whole gearbox.
My PDK experience: I have driven many cars with different variant of double clutch designs including BMW's famous DKG, Audi & VW's famous DSG, Ferrari's DCT, McLarens' SSG, Ford's DPS trash & etc. Porsche's PDK is by far, no doubt that from all the dsg produced out there, nothing beats the experience of Porsche's PDK in the 997,991, 987, 981 & more (Macan & Panamera does not count). The response is just amazing, downshifts are just instant, it is almost that the PDK system has 100% synchronization with your brain at 0% latency. You must be thinking that I am overexaggerating, but I can assure your I'm not.
PDK Flaw Just like many other double clutch transmissions out there, Porsche's PDK has 1 major flaw and that is the distance sensor located inside the rear section of gearbox. You can find many useful info about this specific PDK in the following thread: Guide to Repairing a PDK Transmission In this thread, I will be showing you how I fix PDKs with this specific issue.
Fault Code Present: You might get faults like the following but not limited to: P1731: Shift rod 1 displacement sensor P1732: Shift rod 2 displacement sensor P1733: Shift rod 3 displacement sensor P1734: Shift rod 4 displacement sensor P17XX: 5V ... displacement sensor (don't quite remember this one) If you get any of these faults, it is very likely that your displacement sensor has failed or is failing. If you can't be certain, always refer to the data values, they are helpful.
Before replacing displacement sensor your must: First: Drain all oil & store them in a safe place where it wont be contaminated with debris or water.
Second: Pull the gearbox out of the car, have it come down & the job can be done easily.
Third: Once the gearbox is out & placed somewhere that is workable with. First, you will notice that the gearbox is only 2 piece of housing mated to each other. In this process you will only need to work on the rear section(opposite of input shaft) of the gearbox to replace the displacement sensor.
Fourth: Only in the rear section, undo all T45 sized bolts & I mean ALL. undo bolts circled in red, there's more below, you get the idea...
don't forget this bolt too
Fifth: In this step, you will need to remove the 2 sealing caps. I was able to pry it out slowly with great amount of patience without completely destroying it just so it can be reused. remove the 2 black sealing caps. Do it however you feel that is the safest way if you want to reuse these. Mine does not look too good because I pry-ed it out at least 5 times.
Sixth: Once the caps are out, you will need to undo the bolt from the top cap side and unclip the snap ring from the bottom cap side. Unfortunately, I did not snap pictures for this step, but it will be a pretty obvious procedure once the caps are out of the way.
Seventh: In this step, a special tool will be required. I'm not too sure if this tool is buy-able but we managed to make one ourselves(pictures below). We start of by tightening the tool to the housing, then places 2 thick and correctly sized washers between the 2 shaft and the special tool's screw. Slowly tighten the 2 screws on the special tool and the housing will come right off. If the screws are very tight and the housing wont budge, it is likely that you have missed a bolt that was suppose to come off. I can't really describe how this process should feel so good luck we made this ourselves, not too elegant but it works
you see the two screws between the tool and the housing? the washers goes in between
this picture illustrates pushing out press-fit shafts out of the rear housing using my home made tool
Eighth: Once the rear section it out, you should be able to see the displacement sensor. And if you don't, you are probably not working on a PDK. that's the displacement sensor
Ninth: Removing the displacement sensor is pretty easy. Just undo 3 bolts from the displacement sensor, undo 2 bolts for the speed sensor and lastly, remove the clip at the female connector of the sensor and push it out of the housing. As easy as ABC. undo bolts circled in red
unbolt them
The Last Step:
Out with the old, in with the new displacement sensor (only at T-Design). Once that is done, just reverse the process and perform calibration(with part replacement/overall procedure) with PIWIS II or III.
I was lucky enough to source once from T-Design and it works like a charm
This is their complete guide on how to prepare the sensor for installation >> Instruction for Displacement Sensor by T-Design
If you have any questions, just ask and I will reply as much as I can.
Some picture of the sensor that I sourced from T-Design
the aluminum part came and I soldered it to the harness
Thanks a lot for sharing!
I am replacing the black cap and together with the plastic plug sort of thing. I had difficulty of put them together and broke all the plastic parts when I tried to push them with some tool. They are just too tight fit.
Is there any good way of doing it?
HI all has any one removed the rear case off one of these gearbox's in the car on a 991 4wd ? or has everyone been removing the gearbox first and then splitting them on the bench ? I have done the Cayman/boxster ones without removing the complete box.
Has anyone been able to source or purchase the special tools required for the case disassembly or re assembly? These are the only ones I've found wondering if anyone has experience with them. https://www.ebay.com/itm/16585251692...&segname=11051
Also, when replacing the case screws with steel, has anyone found ones that are as close to "OE" type ( torx) and appearance ( rounded heads)? What are the dimensions?
Has anyone been able to source or purchase the special tools required for the case disassembly or re assembly? These are the only ones I've found wondering if anyone has experience with them. https://www.ebay.com/itm/16585251692...&segname=11051
Also, when replacing the case screws with steel, has anyone found ones that are as close to "OE" type ( torx) and appearance ( rounded heads)? What are the dimensions?
Thank you!
Most of the people here have fabricated their own puller using a steel plate, threaded stock, and nuts/washers. Beyond that there aren't really any special tools needed that aren't available from traditional tool manufacturers. That set you linked does look interesting though, but the price is misleading at $162. Shipping to the US is another $169 on top of that.
Nice to see more and more stuff coming on the market specifically aimed at PDK repair but personally I'd pass on this set and just stick with homebrew.
I'm in the middle of replacing my distance sensor in my PDK ZF.. two questions- what tool is used to close the case or what are the size threads at the end of each shaft.. I can craft a tool. Second, what is the right gear oil. Thanks in advance!
I'm in the middle of replacing my distance sensor in my PDK ZF.. two questions- what tool is used to close the case or what are the size threads at the end of each shaft.. I can craft a tool. Second, what is the right gear oil. Thanks in advance!
This is what I used to fab a simple press tool. I used the OEM oil BTW.
I'm in the middle of replacing my distance sensor in my PDK ZF.. two questions- what tool is used to close the case or what are the size threads at the end of each shaft.. I can craft a tool. Second, what is the right gear oil. Thanks in advance!
Impressive project. Especially since PCNA won't even allow their own dealerships to do this. Ask me how I know. Just glad I had extended warranty for the $20,000 distance sensor replacement or a rebuilt PDK unit. I don't know what I got back but the broken PDK due to the distance sensor was shipped to Germany and I'm guessing I got a rebuilt PDK they had in stock installed rather than the repaired broken one from my car since it was fixed in 3 or 4 days. With a 2 year warranty.
Hope you're successful. Please keep us posted. I'm curious.
Hi Everyone.
We are try to repair PDK but not able to pull rear cover off, even with the tool.
Any tricks? Anything else should be removed? (not only bolts).
Regarding the bearings for the PDK.
The dimensions are: input shaft: 40x80x20/16
Output: 33x80x20/16
The input bearing is easy to find in the size 40x80x20 and here the turned-down edge of 16 can be easily worked by an experienced machinist.
The output bearing is the hardest to find. Here I have found the bearing for a toyota land cruiser gearbox measuring 32x80x20 and had the 16 mm edge machined and the inner ring ground to 33 mm.
I made the first pdk with these bearings over a year ago and just made another one and it works perfectly.
Daugaard
Thanks a lot for sharing!
I am replacing the black cap and together with the plastic plug sort of thing. I had difficulty of put them together and broke all the plastic parts when I tried to push them with some tool. They are just too tight fit.
Is there any good way of doing it?
11-29-2022, 10:57 AM
PDK Repaired
