996 TipTronic 722.6 Transmission Conductor Plate Change : HOW-TO

[bzguy]

Hi all,

 

Here's a little write up of the conductor plate change of my 722.6 transmission on my 996 4S.

DISCLAIMER : I am just a "YouTube certified technician", so this is in no means meant as a Porsche instruction guide, it's how I did it from finding information on the internet ... I am just an aviation IT guy 😉 

So, since about a year, I got intermittent "TipTronic Emergency Run" fault codes on my 4S, randomly, but most of the time they occurred when accelerating a bit harder.

 

I searched online and found out that multiple conductor plate related issues can cause this to happen :
 

- failing  seals from the connector, so oil can leak into the connector causing faulty electrical signals
- loose or failing speed sensor on the conductor plate

Seems that in 99% of the time, replacing the conductor plate solves the emergency run issue, as it happens on Mercedes cars as well (this is the Mercedes 711.6 transmission, used in multiple Mercedes/AMG models)

So I decided to order the parts and do it myself, as I was quoted between 2500-3000 EUR by Porsche approved mechanics.

And here's the shocker : the conductor plate, which is  Mercedes part, was quoted  :

- 940 EUR from Porsche

- 410 EUR from Mercedes
- 133 EUR from Febi, which is the producer of this exact conductor plate

 

This is for EXACTLY THE SAME conductor plate !

So, I started cracking :

1 ) Drained the transmission oil, on the photo below I indicated where is the drain, overflow and fill plug :

 

2 ) Removed the transmission brace & oil pan (2 15mm bolts for the brace & for the pan 6 torx bolts & oil pan retainers), removed the transmission oil filter :

 

3 ) Then removed the whole transmission plate (10 torx bolts, quite heavy plate !). Before doing this, you have to remove the wiring plug that connects to the back of the transmission, to the big round connector. So undo the plug, turn the beige connector tab counterclockwise about 90 degrees, the plug will release a bit, so you can remove it.

Then, inside the connector, undo the 7 mm bolt. There is not a lot of space behind it, so impossible to use long tools. This is a bit annoying, took me a couple of attempts to succeed. Once the bolt is removed, you can remove the connector and start removing the whole transmission plate.
 

 

 

4 ) And here's the transmission plate with the conductor plate on top ; the conductor plate is the black part with the solenoids etc :

 

5 ) And here's the Mercedes stamp ; yes, Porsche uses this Mercedes part, as it is a Mercedes transmission after all :

 

6 ) Here is the speed sensor, of which the connection to the conductor plate felt rather loose (seems to be a common issue) :

 

7 ) And here's another issue : the failing connector seals caused oil to leak into the connector :

 

8 ) I removed the 3 solenoid retaining clips, removed the solenoids, and unclipped the old conductor plate, the clipped on the new conductor plate, put back the 6 solenoids and their retainers, 8Nm torque :

 

You can clearly see that Febi sent me exactly the same part as the Mercedes one, but the part number has been scratched off, but the mould reference is still visible, the PA-66GF 30 mark is still there 😉 Febi is the original manufacturer after all 😉 
 

9 ) When reinstalling the transmission plate, make sure that the gear selector pin inside the gearbox & the notch on the transmission plate align ! The notched part moves forwards/backwards depending on what the gear selector is in (PRND), the pin and the notch match up :

 

 

10 ) I put everything back :
 

- transmission plate with 10 bolts and new conductor plate on it, 8NM torque
- new transmission oil filter, pan seal, transmission pan bolts 8 Nm
- new transmission sump plugs and seal ring, tighten sump plug to 20 Nm

11 ) And the the most difficult part of it : putting in the new connector onto the conductor plate & reconnecting the plug :

This is a definite pain in the ... you can reach the connector hole with one hand, on the back/side of the transmission, you can only fit 1 hand in there, you can't see anything either, as there is NO space (engine is just behind it), there are tubes etc ... so only way to do this is to blindly feel and try, and ty again and again and again, and have LOTS of patience 😞

The new connector can in only 1 way, because there are notches inside and they need to lign up with the conductor plate. Once you can feel them lign up, be careful when pushing in the connector, as it is tight with those new seals (make sure to lubricate them a bit), make sure to not bend the pins !

Once the connector is in, you can start tightening the 7mm hex bolt inside the new connector ; I had to grind down a 7 mm socket, so it'll be less deep, so it helps to push in the bolt.

Then you can connect the plug, again it can in only 1 way, just take your time to feel how it goes in before you push, avoiding bending pins from misalignment. This is the most critical step in my opinion. Then push the tab on the new connector about 90 degrees clockwise, it will pull in the plug.

These are BY FAR the most difficult step of the whole process, it took me 45 minutes to achieve this step, just being patient and trying over and over again, as to not risk damaging the new conductor plate.

 

12 ) Put the transmission brace back.

13 ) Fill the transmission until oil starts dripping out from the overflow plug ; the filler plug has a kind of ball valve inside, so oil can only go in, not out. Make sure to only remove the filler cap before filling, not the whole valve body ! I used Mercedes Original MB236.14 transmission fluid, as prescribed thy Mercedes.

14) Once oil started dripping out, I closed the transmission fluid pump

15 ) I then started the car, let it warm up to 30-40 degree transmission sump temperature.

16 ) I ran through D, for 10 seconds, then 10 seconds in R, and then manually through every gear.

17 ) I topped up the transmission poil, again until it starts dripping out, I think it took about 1,5 l more, as all the valves/vains/solenoids etc inside fill up with oil

18) Closed the filler plug, took it for a test drive, all was ok 🙂

I found some very helpful videos on YouTube, like these here (no affiliation, just referring to what helped me), credit where credit is due :

 

 

Edited Wednesday at 08:15 AM by bzguy