Leaderboard

Hello Everyone. Please find my first tutorial submission. Replacing the Valve Body (aka valve chest) in a 2003 Cayenne Turbo Symptoms: Very harsh shift from 1-2-3 when under load (like getting rear ended by a truck) Hesitant shifts and flaring when driving normally. "Clunky" shifts. Vehicle has travelled around 210,000km. Fluid has never been changed (dealer said is was not necessary-which is not true!) After doing lots of reading it seemed like the valve body (VB) was the likely culprit. You can either replace with a new VB or have your old one re-built. If you replace the VB with a new one, you also need a new transmission control unit, and the problems will most likely re-appear. I went the re-build route and chose RevMax converters based on other people's experience. Note that RexMax don't ship outside the USA, so as I live in Australia, I used my wife's USA2ME mailbox, and they sent it on to me. I also had to send my old core in as they didn't have one in stock, but I'm glad I did, as there are several versions of VB depending on the year of your car. They rebuilt it within 48 hours. As you will need to drain and re-fill the trans, I won't be covering that in too much detail as it is covered extensively elsewhere (see my reference links below). Parts list 1) Auto trans filter 955-307-403-01 2) Auto trans filter sealing O-ring 955-325-443-00 3) Filler Hole seal O-ring 955-321-379-00 4) Crush ring for transmission drain hole - sorry didn't have PN for this as I forgot to order it! I re-used my old one. 5) 3 x Long VB retaining bolts WHT 000 321 6) 11 x short VB retaining bolts WHT 000 324 7) Transmission pan gasket 955-397-016-00 8) Case (12 quarts) of Mobil ATF 3309 or Toyota type IV Transmission fluid (It is the same stuff do don't panic if you can't get Mobil or Porsche branded fluid) Tools List 1) 1 x micro torque wrench (range 2-20 ft-lbs) 2) 1 x normal torque wrench (for torquing the fill plug to 70 ft-lbs) 3) T40 Torx bit to remove drain plug 4) 17mm Hex bit for fill plug 5) 10mm socket (apart from the drain plugs everything is a 10mm socket) 6) general other sockets and screwdrivers. 7) Durametric software to read transmission temp and re-set adaptation (you can get buy with a temp probe on a multimeter, but it was much easier to use the software, and IMHO if you are attempting a job like this you really should get it. It'll pay for itself on this job alone). 8) A willing assistant to help with the re-fill procedure. Reference - read this stuff first and print out the relevant pages 1) Official method for removing the valve body http://www.inkilino.es/Porsche_Cayenne_02-06/AUTO%20TRANS%20GEARS%20CONTROL.pdf 2) A really nice tutorial on draining and re-filling the transmission in addition to the ones on Renntech by ECS tuning http://bd8ba3c866c8cbc330ab-7b26c6f3e01bf511d4da3315c66902d6.r6.cf1.rackcdn.com/CayenneTransmission.pdf 3) there's a brief write up at club touareg that I used as a starter http://www.clubtouareg.com/forums/f73/transmission-valve-body-diy-on-2004-touareg-v8-09d-trans-64189.html Part 1 Removing the Pan and Valve Body 1) Remove the underbody protection panel. 2) There is a 2 peice bracket that holds the protection panel up, unbolt it in the centre and side and remove it. 3) My car had a strong bash plate over the rear of the transmission pan, it will need to be removed in order to access the rear pan bolts. 4) Drain the fluid from the pan (First make sure you can budge the large fill hole-It's really tight I had to use a big metal bar to crack it, once it's "cracked" you can then remove the T40 torx drain plug). Best to drain the fluid cold after it's been sitting overnight. You'll drain an easy 5-6 quarts here. 5) Remove the ATF Pan bolts (all 10mm) and save them - they can be reused. 6) Gently knock the pan to break the seal and remove it. 7) Remove the 3 10mm retaining bolts from the ATF filter and remove the filter. Make sure the seal ring comes out too. More fluid will come out. Discard filter and o-ring. You should not be able to see the valve body as below. Take a picture and make notes as to which wire goes where. It's actually not that complicated as the wires will only really go in one spot when you re-assemble. You also need to note how the selector shaft engages with the VB as below. Again this looks tricky, but it was dead easy to put back together. Here's a close up of the shift solenoid wiring harness showing the green connectors in the black housings. Here's a pic of the other side. You can see another solenoid, plus the two pressure switches (gold colour) and up the back the large white output shaft speed inductive pickup connecter. Note how the white connecter clips onto the bracket and also how the wiring is tucked under the bracket. 8) Now work your way slowly around the 5 solenoids on the shift selector side removing the green connectors. I used a small screwdriver to depress the little clip and lever them out. You should not need to use hardly any force on these. You don't want to damage them at all. 9) Remove the 2 black cable plugs at the rear of the VB and the single solenoid green connector at the front of the VB. 10) Next pull off the plug for the input shaft inductive pickup. This is located at the front of the trans, right up in the "guts" of it. It looks really tricky, but using a long screw driver it came right out. Putting it back in was also really easy, so work slowly and don't panic. 11) Next pull off the two cables from the gold pressure switches. They just pop right off. 12) Remove the bolt holding the ATF temp sensor (2 orange wires) and pull the sensor out. It's held in by an o-ring. Save the bolt and retaining bracket. Don't remove the sensor from the wiring harness, just let it dangle with the rest of the wiring harness. 13) Remove the large white connector at the rear of the VB (output shaft inductive pickup) from the bracket and unclip the white connector. 14) Remove the steel bracket and save it and it's bolts. 15) Remove the 2 gold pressure sensors (if you get the VB rebuilt you'll get new ones, but hang onto them just in case). Now all the wires should be free. Tie or secure them gently so they're out of the way. The VB is very heavy and will also dump a heap of fluid when you remove it, so you don't want to snag the wires at all. 16) Now remove the valve body by removing the 14 bolts around the outside. They are all 10mm. I removed all but 2, one at the front and one at the rear, then slowly loosened them allowing the VB to tilt forward. This allows some of the excess fluid to run out. There is still easily 2-3 quarts of fluid in there so it's messy. Again take care the VB is very heavy, expecially if you are working on your own. Here's the transmission with the valve body removed. Note the black wire in the centre of the transmission is the output shaft inductive pickup that is attached to the big white connector. Clean up the VB and send it off to be rebuilt. Part 2 Installing the VB 1) get all your parts together. Note the valve body retaining bolts CANNOT be re-used, so make sure you got new ones. 2) Gently place the VB in it's position. Make sure the selector shaft mates correctly with the VB. Mine almost just fell into place itself. Also make sure that none of the wires are snagged especially the output shaft wire (big white connector).If you've secured them out of the way this won't be a problem. I put in 2 bolts to start with to get the position right and take the weight. Only do them barely hand tight. This is really important as the torquing process will be ruined of you do them up too tight to start with. 3) Put in the rest of the bolts and tighten them up by hand so the VB is in place and mated correctly to the transmission. If you get the bolts in the right place, you'll be fine. Don't do them up too tight! 4) Now the bolts need to be torqued in 2 stages. Initially using your micro torque wrench to 6 ft-lbs (8 nm) and then finally through an angle of 90 degrees (quarter of a turn). I had an angle gauge, but I couldn't find a good spot to use it against the transmission body. So in the end I just torqued them by "eye". 90 degrees is easy to judge. So to re-cap. Torque all bolts initially to 6ft-lbs and then once you've torqued all 14 bolts, the go around and torque them AGAIN through 90 degrees. If you have one of those fancy digital torque wrenches, it may also do angular torque for you. Here's the new VB installed in the transmission. Note the wires are hanging neatly to the side. 5) Reinstall the two gold pressure switches (torque to 3.25 ft-lbs/4.5 nm) and also re-install the bracket you removed that holds the white output shaft inductive pickup wire connector. Make sure the wire is routed correctly under the bracket and attach the white connector to the bracket as below. 6) Connect the other white connector from the output shaft pickup 7) Replace the ATF temperature sensor using the bracket and the bolt. Note the wire points to the rear of the VB. Torque the bolt to 7.5 ft-lbs/10nm. 8) Plug in the 2 cables for the gold pressure switches. 9) Plug in the cable for the input shaft inductive pickup. This is the one that's right up at the front of the transmission. For me it went straight in no problems at all with a nice positive "click". It looks a bit daunting, but was surprisingly easy to re-connect. 10) Plug in the remaining green six green connectors, and the two black connectors at the back of the VB. Compare the wiring layout to the picture you took before you unpluged them all!. If you didn't take a picture, don't panic, the wires only really go one way, just make sure they're nice and neat. As a guide the orange temperature sensor wires go under the green/brown solenoid wire. 11) Next reinstall the ATF filter using the new O-ring. Torque the 3 bolts to 7.5 ft-lbs or 10 nm. It should all look like this... 12) Next put the new Pan gasket in place on the pan and using the old pan bolts install the pan and torque the bolts to 7.5 ft-lbs or 10nm. I put a little drop of Permatex blue threadlocker on them for good measure. Here's a picture of the nice clean pan and new gasket next to the old gasket. Make sure the pan and magnets are all clean. Just wipe it out. I didn't want to use degreaser in case it contaminated the trans fluid. My magnets weren't too dirty. I've seen pictures of this trans in an Audi and the magnets looked like little Chia pets!! Install the small drain plug and new crush ring (doh!) and torque to 21 ft-lbs/28nm. 13) Now cold fill the pan until fluid comes out the fill hole. It took about 4 quarts. I used a $8 garden sprayer, and put about 2 feet of clear hose on the end with a hose clamp. This allowed me to have the pump bottle at the ground, and put the plastic tube into the transmission so it hooked over the fill tube. It worked brilliantly! Here's a picture of the bottle I used. Here's the top of the setup. You can see the plastic tube going into the transmission. I also had my multimeter temp probe in there, but it turned out I didn't poke it in far enough so it couldn't pick up the temperature. I used the Durametric software instead. 14) Now for the "hot" fill procedue. Make sure your fill bottle is full. I ended up using a total of 10.5 quarts to refill the transmission (this is more than a normal fluid change as the VB has been removed), so I had to refill the fill bottle half way though the procedure. You have to move quickly as once the temperature starts to move on the transmission it only takes about 5 minutes to get to 40oC. I set my laptop up in easy reach (make sure it's fully charged or better still connected to AC) and also had all my bottles of ATF at my feet. 15) Have your assistant start the car and you start filling the transmission. I added another 4 quarts in a few minutes. Ask your assistant to move from P to R to D and back again with about a 3-4 second pause between each shift. Do this once. 16) Keep filling the transmission, and watching the temp on the software. Once the fill bottle was empty quickly re-fill it, re-pressurise and keep filling. Get your assistant to do the shift sequence again. I found that at about 32-35oC the trans was getting full. Fluid will start to leak back out the hole, so make sure you've got a drain pan under the hole! 17) Keep filling and execute another shift sequence. At about 38oC I got another shift sequence done, and then put a but more fluid it. 18) At 39oC fluid started coming out the hole a bit faster, and at 40oC I quickly pulled out the tube and put in the fill hole socket. Torque it to 70 ft-lbs. 19) Stop the car, using the durametric software execute the Reset Adaptation command for the transmission. After that go for a test drive! As the transmission control unit is in learn mode, you should try to do all sorts of driving styles. This has solved all the shifting problems I had, it really drives like a new car. Even my wife commented on how smooth it is now. Check for leaks and replace the underbody panels etc. Enjoy your new car!