Damien Law

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

docdrs

Great write up. Many members will be happy to see this. Looks like maybe it could be done without dropping the box in Boxster’s not so sure about anterior clearance on 911’s Please update as to performance after the fix

Ironman88

In an effort to maintain some continuity on the topic, the link below offers substantial supplemental information pertaining to PDK repair...

https://rennlist.com/forums/997-foru...ission-17.html

Info on T-Design:

https://t-design9.com/about_us.html

Info on the T-Design PDK Position / Distance Sensor:

https://t-design9.com/porsche_PDK_di...on_sensor.html

We'll see where all of this goes in time. Hopefully it is a viable, sustainable solution.

PV997

Thanks Damien for the great write-up, nice to have details on how to separate the case and some feedback on the replacement part itself.

I added info and a link to the T-design part in the PDK repair sticky with the caveat that the jury is still out (for now at least). Hopefully the reliability holds up, looking forward to future updates. I'll also incorporate Damien's instructions for splitting the case in the post.

Feels like we've turned a corner with the PDK and Porsche's ridiculous policy. We've now had successful DIYs for the clutch fluid pressure sensors, the valve body, and the distance sensor. Gotta love the folks who refused to take it and blazed a trail on this. Stubborn and frugal are a powerful combination!

Edit: The Porsche PN for the plastic end caps Damien shows is 9G1.321.360.00, and they are cheap at $5 each.

t-design

You are correct, it's a new product, so our longest statistical data is 6 months, not years. But we designed it to highest specs - continuous operation at high temp and chemical resistance. Every single component is temp rated to 150C/300F or higher. And we did a hell of a lot of tests, including freezing temps operation. So we fully expect it to last long long time!

Don't forget the power of the community! This Rennlist forum is truly a bottomless source of knowledge and ideas. And we are proud sponsor of it!

And here's a drawing of puller tool, provided by Niklas Vemdal:

ADias

Kudos! Now you need to design/manufacture the end sealing caps. That would complete the repair.

yarindadon

hello guys I have the same issue with displacement sensor, is there any chance to take it out and try to refurbish it instead of buying one?

amet

Porsche has them

https://www.sunsetporscheparts.com/o...se-9g132136000

PV997

I tried but failed. The potting ZF uses is rock hard and I could not get it to soften much even with very high heat. It does become somewhat brittle with heat but the internal components are fully encapsulated by the potting and chipping it out damaged them. I was able to figure out the design from what I found inside but as T-design notes it's nearly 15 year old technology. Apologies for not posting about this back then but numerous personal issues had me preoccupied.

Thanks for the temp info on the components T-design, we'll be watching closely and hope you have a winner on your hands. I'm thinking this part works for all PDK vehicles from 2009 though 2016 (all 7-speed PDKs) but please confirm.

Damien - What torque did you use for the case bolts when reassembling? Also, I assume you must have used RTV at the seam as there's no gasket?

If anyone else is doing this please try and get the part numbers off the two bearings in the end case after separation. They are replaceable and I'd like to add the info to the PDK sticky.

t-design

Yes, all 911s and Boxsters/Caymans PDK since 2009. We've seen 3 different part numbers on the sensor pack, but it's exactly the same part (0501325775, 0501327105, 0501324703)

There is some confusion going on about "reconditioning". As when batch of Chinese salvaged parts was available some time ago - some retailers called them "reconditioned". But there was nothing reconditioned about them, except they were cleaned after removing them from gearboxes of accident cars. And they are no longer available... for couple of years, if I remember right. Yet links our out there on internet, some for $10 , confusing people even further. Like none of the Chinese used sensor from post #1 here can be purchased. They are long gone.00501325775, 0501327105, 0501324703

t-design

Here is a picture where bearings and cups are clearly visible

PV997

Yes, I should have made clear it doesn't apply to the Panamera or the SUVs, but only the sports cars. Does it also apply to the 8-speed PDK in the 991.2? I'm not that familiar with it but assumed it was different as the gear layout changed.

Those ZF part numbers probably rolled due to internal component obsolescence or maybe to improve component reliability (parts screening) on the later versions. Function-wise I agree with you that they behave exactly the same. Good work on this!

amet

you can see the gasket in the below photos, it’s aluminium and Teflon (I think) gasket that can easily be reused if the case is separated properly without the use of a screwdriver

PV997

Good catch, don't know how I missed that. Thanks!

sandwedge

Six months or whatever, you're still ahead of Porsche and ZF on this. Unless there was miscommunication between me and the dealership, the failure of this sensor was what required full replacement of the PDK on my car fairly recently. Not at home so don't have the exact date of the failure but I'm guessing around 6 months ago. Their reason for full replacement due the failed sensor? They can't get that part from ZF for the earlier PDK's anymore. Mine is a 2011.

At least I had warranty that covered the $20,000 replacement. Over a sensor that costs what?