This forum has been incredibly slow lately.

In the process of doing some online research on my pepper, I ran across a Four Wheeler Magazine article (2009) in reference to testing the 957 CTT offroad - from a proper offroad source.

Not surprisingly, it seems to have "cut the mustard". Feel free to reference this article when others snicker at the offroad capabilities of your Cayenne:

"We recently 'wheeled a top-line Cayenne Turbo, and based on our time behind the wheel, we can happily report that its trail manners would appear to be far superior to the previous model's. One thing we learned, and certainly didn't expect, was that our tester's 35-series Michelin Sports (yep, we wheeled on a set of 21s, and obviously at street pressures) delivered much better traction in the dirt than we'd have assumed them capable, given their virtually voidless tread pattern. (It should go without saying that they're outstanding on pavement.) It took us some effort to get them to spin, but spin they eventually did-on a loose-shale hillclimb-and this was where we learned that the Cayenne's traction-control system is indeed more refined and driver-friendly now. Where previous engagements had resembled a drunken ballet, there was now a much smoother transition from spin-up to hook-up, with only slight levels of ABS feedback and no need for extra throttle. We also noted the tires' ability to stay planted on the trail, despite our best efforts to cross them up on off-camber ledges, so we'd have to surmise the new sway-bar disconnect does its thing very well, too (Porsche claims it provides an additional 9 inches of travel). Naturally, we wouldn't advise taking the Cayenne out for any rockcrawling duties, or anything else that would require airing down (not with a 35-series sidewall, anyway), but as a moderate-duty trail rider, the new Porsche seems quite the able performer now."

Read the full article here: http://www.fourwheeler.com/roadtests..._turbo_review/

 

Nice review!

 

Is the 6 speed Tiptronic transmission in the 957 Cayenne an Aisin unit like the 955 or is it a ZF unit as the review states?

 

I'm almost positive it's an Aisin.
I'm kind of surprised at the negative comments they had toward the 955. I'm guessing they didn't have the Advanced Off-Road Technical Package in the 955 they tested, or the decoupling sway bars wouldn't have been such a new thing to them.

 

Im just trying to figure out what the difference is between a 955 and 957 drivetrain, since they commented on the superior drivetrain of the 957.

 

Thats interesting b/c I looked for this specifically a few weeks ago and thought I read that the transmission was designed by ZF and the electronics were made by Bosch. Which I suppose is good news since ZF seems to be all the rage in performance transmissions.

I will see if I can find the source.

This now makes sense to me.

Before I got my 957, I thought I read that unless you got the Advanced Offroad Package (which many peppers do not have), you will not be able to have it completely disconnect the sway bar ends. Fast forward to a several months ago, during Hurricane Sandy, I was driving around in low range and had to pop a few 5" concrete parking barriers (due to down power lines) and hardly felt them! I was convinced that PDCC had to disconnect the sway bar ends - it was the only logical conclusion.

I guess what I read prior only applied to the 955.

 

The drivetrain consists of the engine and tranny in the US. So the 957 got the 4.8 liter V8 vs the 4.5 liter V8. The electronics for the tranny was definitely upgraded, still trying to confirm a new manufacturer, ZF, as well.

 

Sounds more like it was an option level difference more than a 955 to 957 difference.

It would be fairly easy to add sway bar disconnects like Jeeps do in the 955.

 

Posted below from the referenced article, it looks like the tranny may be a ZF make on the 957 due to the clutch plates and bearing upgrade.

"Backing the 4.8 is an upgraded version of the venerable ZF Tiptronic six-speed manumatic transmission (with more clutch plates and reinforced bearings) with Hill Hold and auto-Neutral tranny-brake functions, as well as continuously variable shift algorithms that adapt on the fly to your style of driving."

The latest 958 series are said to have the new 8 speed tranny sourced from Aisin.

Would Porsche swap from Aisin (955) to ZF (957) and then back to Aisin (958)?

 

The article must just have bad information. I just looked up the transmissions for the 955 and 957 in the Porsche parts catalog and its all the same part numbers, all starting with "955"

Fwiw, my 04 Turbo has "hill hold", etc

 

Wait a minute... this contradicts my information from the PET catalog which says that the 957 CTT has a different transmission number than the 955 CTT (can provide screenshots)

There are a few different replacement transmission part numbers listed for any submodel (depending on what is stamped on your transmission):

957 CTT Part Numbers:

955.300.011.52

955.300.011.53

955.300.012.FX

955.300.012.BX


955 CTT Part Numbers:

955.300.011.51

955.300.011.26

955.300.011.24

955.300.011.22

As you can see none of these transmissions numbers match up. This is further substantiated by doing a search on 957 part number 955.300.011.53 on Jim Ellis Porsche site, which says this part number only cross-references to the 957 2007-2010 model Cayennes - not the 955 year range.

If anything, this is a strong case that the transmission was upgraded or switched manufacturers to ZF.

FWIW, the 955/957 CTT is listed to have a different transmission from the other V8 variants.

 

I'm sure there were updates made to the transmisson to work better with the PASM so the "transmisson itself" probably has a slightly different valve body etc.

Look at the part numbers for all the little tid bits that go around the transmisison like bolts, wire harness clips, heat shields, mounts, TCase. If it were a different transmission ALL of those parts would of had to change. I looked at a couple of the outside bit part numbers and they matched.

There is probably also a reason all of the transmisson part numbers start with 955 and not 957

 

Here you go. Published in 2010. Shows the same transmission from "2003-up"

http://www.scribd.com/doc/94362555/09D-Cayenne

 

Oh.. now I am following your logic trail. This notion is based on the assumption that since there is a 957, then the part numbers should begin with 957, instead of 955. However, I am afraid that naming conventions a lot times do not make sense. I think it goes without saying, that I spend a lot time doing research on my 957 in PET for new projects and NONE of the part numbers I order from my dealer ever begins with 957 - they always begin with 955.

For instance, it you look up the 4.8 engine in the PET catalog , which is clearly completely new for the 957, it still begins with 955 in the part number. For some reason, the distinction in PET comes from the chassis code with has "9PA" for the 955 and then "9PA1" for the 957 year range. I think it would make more sense too to just bake this into the part numbers- we are talking about Germans here.

Good find! However, am I missing something? I only see where it says that Aisin made the Cayenne transmissions from 2003-up on the V6 exclusively on page 3. There is no mention that I can find of them saying that it is on the 4.8 V8. Am I wrong here?

 

Buy page 4 and find out.

Can't imagine they would use the same trans through all of the model line and touregs for the entire run and go to a completely different manufacture for one sub model