Cuba

I'm also suffering from rough shifting, intermittent, mainly down shifts at this point. I believe it to be the valve body issue others have mentioned, I'm at about 68K miles so figure I might as well get it done now. I understand I need to install a new TCM along with the valve body, but can't find a source for either. I've found some remanufactured valve bodies from companies I wasn't overly comfortable ordering from online, but no one seems to have the TCM, and I also don't know which part # to get. Does anyone have experience sourcing these parts that can chime in, and do I need anything else besides a lot of ATF?

Slow Guy

Mine were done under warranty a couple years ago. IIRC the TCM had to be programed to the car. Sorry I can't be more help.

Cuba

So it seems the dealer route is really the only way to go here. For all the parts and fluids required I'm looking at a little over $1500, and that's at employee rates. They're only charging me 2 hours of labor on top of that, so for around $1700-1800 I'll have it done by the pros and hopefully should last a long long time. I'll update with the actual parts list and before/after observations when it's done next week.

My plan is to do a nice general refresh this year for longevity and piece of mind, as well as a tune. We'll do the diverter valves this weekend and possibly tune if the mood strikes. Aside from these occassional hard shifts it's really been trouble free, everything works perfectly and it's been a lot of fun. Not bad for a two thirds depreciated high performance fat pig.

hahnmgh63

I think I would go with one of the rebuilt & modified Sonax valve bodies from one of these places:
http://www.makcotransmissionparts.com/P15740-1.html
http://revmaxconverters.com/about/shop/09dlate
Does the TCM (TCU) need to be replaced or just flashed with new software?

ArneeA

These are not bad prices for the Cayenne. BMW valve body for the X5 cost around $3k and it was a dealer-only part.

Cuba

TCM does need to be replaced unfortunately. I thought about the revmax but just felt uncomfortable, I know nothing about them and never heard a review good or bad, and just thought that if I'm spending the coin I might as well get a new one. I like to heavily research such things and didn't have a source of data, I guess most were just getting $11K transmission replacements under warranty for this issue.

Cuba

I'm guessing the total job would have been around that at a dealer. I just know people

While I'm going the dealer route this time I can certainly supply all the applicable part #'s and estimated costs for those that want to do it themselves. The work itself is fairly simple but I know the transmission refill is touchy (perfect fill at proper temp) and I still don't know exactly what they do with the programming but I'll find out. I can turn a wrench just fine but software issues scare the bejeezus out of me.

silvercayenneS

Hi - I have the same problem in my 04 S -- a loud clank after the first shift, and then forward surges on downshifts -- which part would I order? Thanks!!

Cuba

I don't have my parts list yet but I'll ask for it this week. The job is done, valve body, TCU, Fluid flush, driveshaft check (still okay but showing some dry rot), and recalibrated the ride height so now it sits 2.5cm lower. Parts were $1703 with tax (heavily discounted), and labor done by the book I believe to be 4-5hrs of shop time.

It's running great now, drove 600 miles the next day and it shifts smoothly without issue. My Porsche tech buddy says this is a very common occurance in his opinion and has done quite a few. He feels the transmission itself is a very durable unit except for these older valve bodies and should be trouble free for a very long time after getting this done.

Unrelated but he also mentioned that the new ignition coils end in "08" and are a huge improvement in durability. They're $80 a piece but if you've had them replaced previously by Porsche there's a significant discount offered.

ArneeA

Cuba, that's great pricing...

hahnmgh63

Cuba, here is what I've got when I put in the '08' part # into Sonnen's website. The last I heard was that the '08' was the latest part # but I guess we have another newer one again.

Old Part Number 94860210408
New Part Number 94860210409
Part Name PENCIL COIL
MSRP $54.02
Core $0.00
Online Price $39.16

endless_corners

Where is the TCM located? i know the valve body is under the pan.. I am trying to get a handle on all the parts that are needed for the valve body job. After calling sunset audi/porsche in OR (my nearest dealer) the service manager mentioned it was just valve body, fluid, and filter/gasket. Do you think he just omitted the TCU/TCM? My 04 CS exhibits intermittent ABRUPT downshifts from 5th/6th --> 4th/3rd, slow shifting, and lurching shifts from 4th into 5th. From searching the forums it sounds like the valve body and the service manager agreed with me. I am trying to understand how the TCM fits into the picture. Can anyone explain why a new TCM is needed with the valve body replacement? thanks

rowlands57

TCM is under the passenger seat.

Cuba

That does sound like what I had, techs describe it as the car trying to launch you into the windshield although mine wasn't quite that bad. My understanding is the TCU is needed because it's a new design for the valve body and I think they said it has another port or something so it needed new computer hardware rather than a reflash, but who knows. The TCU itself was less than $300 with friend pricing. I've been lazy about it but I'll call about the part list this week, it was just too nice out last week to do anything other than BBQ in the sun and drink too much.

Cuba

Nice that pricing sounds a bit more palatable. Supposedly the 08's are way more resistant to the heat than the older ones which was the source of the problem.