DCT / PowerShift Transmission Update TSB Thread

[kam327]

Just had a thought - I might remove the engine bay lower cover to get more cooling airflow on the tranny.

[dan50]

Originally Posted by kam327

Guys, I am in the exact same boat. December 2 build, January update applied, 1450 miles on it now. I had violent "hot shudder" until I did the 5 full throttles and started driving more aggresively and it was reduced to a mildly jerky start, but still only after having driven in rush hour traffic for 15-20 minutes. From cold up until that 15-minute point, shifts are perfectly smooth and no shudder or hesitation.

Yesterday I did some suburban errands in easier traffic than my typical rush hour drive and the jerkiness was NOT there, even after half an hour of driving. I think it's crystal clear that the clutches are overheating, or at least they weren't designed to operate smoothly at this level of heat.

I'm beginning to think this is a design flaw and all the others on here that keep reporting "no problems" just don't put the clutches through the work that we do on our commutes. By "work" I don't mean driving aggressively, which I'm sure most do on here, but rather "commute work", lots of slow starts and creeping along due to heavy traffic.

I know some have recommended "just don't creep" and to always make hard starts, but that's just not always possible in heavy suburban traffic.

I have yet to take an interstate trip yet so I can't comment on the clutch behaviour after 20 minutes at a constant 75.

Thoughts?

I agree that this is a design flaw that may not be noticed by some because their driving style simply doesn't produce the temperatures needed to make the clutches misbehave.

It's surprising that a long interstate drive would generate the heat. Makes me wonder if the "microslip" Ford designed into this masterpiece is a bit less "micro" than intended.

Really a shame because the car is quite exceptional in other ways.

Take a highway trip. I think you'll really like how the car performs. Until you take the exit ramp, that is.

[VOLDAR]

To all of you who have problems with shuddering after 1000 miles, I'd ask you a question (simple one) : Do you really drove your car to get great mileage or to broke-in the DCT ? I am sure (almost) all of you drove with a feather leg, only to gain some 2 dollars at the fill-up and post > 32 mpg in other threads.
I have 12500 Km on mine (since September) and experienced shuddering only twice (at the beginning). And I can tell you something: here, in Montreal, usually we spend 1 hour in traffic to drive 3 km from South shore to the island. And I know a lot of people here who drove their cars in the heat of the summer of 2011, so I can't do anything but laugh when I read all your "knowledgeable" thoughts about "DCT has a flaw design due to heat". Come on ! What school were you at, because I sure would not like my children go there.

[dan50]

Originally Posted by VOLDAR

To all of you who have problems with shuddering after 1000 miles, I'd ask you a question (simple one) : Do you really drove your car to get great mileage or to broke-in the DCT ? I am sure (almost) all of you drove with a feather leg, only to gain some 2 dollars at the fill-up and post > 32 mpg in other threads.
I have 12500 Km on mine (since September) and experienced shuddering only twice (at the beginning). And I can tell you something: here, in Montreal, usually we spend 1 hour in traffic to drive 3 km from South shore to the island. And I know a lot of people here who drove their cars in the heat of the summer of 2011, so I can't do anything but laugh when I read all your "knowledgeable" thoughts about "DCT has a flaw design due to heat". Come on ! What school were you at, because I sure would not like my children go there.

Very nice and enlightening comment. Glad you don't have problems with yours. Unfortunately, mine is different. But I guess that is worthy of an insult.

[VOLDAR]

No, it was not an insult. It was like calling Sarah Palin stupid (more or less, we can discuss about the %, but in the end she is). I read all you said about the heat and the environment temperature influence over the DCT, and I can't stop thinking how bright you think you are and how stupid Ford engineers may be. Is this the pride of "buy American" ? If you have a point about the MFT, I can't think you know anything better about the DCT than the ones who designed it and tested it. And yes, some of these tests are also extreme conditions. But hey, what do I know ? There are some here who just know it all. My bad. I'll just keep the laughs for myself next time.

[kam327]

Originally Posted by VOLDAR

No, it was not an insult. It was like calling Sarah Palin stupid (more or less, we can discuss about the %, but in the end she is). I read all you said about the heat and the environment temperature influence over the DCT, and I can't stop thinking how bright you think you are and how stupid Ford engineers may be. Is this the pride of "buy American" ? If you have a point about the MFT, I can't think you know anything better about the DCT than the ones who designed it and tested it. And yes, some of these tests are also extreme conditions. But hey, what do I know ? There are some here who just know it all. My bad. I'll just keep the laughs for myself next time.

Oh I forgot, the car manufacturers ALWAYS execute new technologies PERFECTLY when they embrace them for the first time. Yes, yes, Audi's embrace of the CVT 10 years ago went swimmingly. Seriously dude, to suggest the engineers are infallible bringing out a new technology (for them) is about the lamest argument I've heard.

I've got a question, why are you trolling a thread on DCT Updates at all if your DCT supposedly works absolutely perfectly? Why don't you leave this thread to those of us with legitimate problems who are trying to brainstorm to come up with a plan of attack?

Or make yourself at least minimally useful and explain why my tranny shifts perfectly until 20 minutes into heavy stop and go traffic when it starts to shudder, and even then only from a stop in 1st gear. If shifts perfectly even after 40 minutes of driving in light traffic, like this morning since traffic is much lighter due to spring break. It's only the stop and go traffic that eventually brings on the shuddering.

Yes fuel economy was the primary reasons I bought the car, otherwise I would have continued driving the Explorer V8. So what? What you seem to be implying is that this car is only suitable for enthusiasts who are going to be redlining it from every stop. Newsflash: that's not how Ford is marketing this car.

[csvt2060]

Originally Posted by VOLDAR

To all of you who have problems with shuddering after 1000 miles, I'd ask you a question (simple one) : Do you really drove your car to get great mileage or to broke-in the DCT ? I am sure (almost) all of you drove with a feather leg, only to gain some 2 dollars at the fill-up and post > 32 mpg in other threads.
I have 12500 Km on mine (since September) and experienced shuddering only twice (at the beginning). And I can tell you something: here, in Montreal, usually we spend 1 hour in traffic to drive 3 km from South shore to the island. And I know a lot of people here who drove their cars in the heat of the summer of 2011, so I can't do anything but laugh when I read all your "knowledgeable" thoughts about "DCT has a flaw design due to heat". Come on ! What school were you at, because I sure would not like my children go there.

So what are you saying here? Bashing people who drive to get good gas mileage and then implying that's why their transmission doesn't shift right?

And then you are the one questioning someones education? What a joke.

[r1derbike]

What is at least one cause of shudder/chatter?

Glazing on the disk(s) and hard spots on the pressure plate and flywheel caused from heat created by excessive and prolonged slippage.

Stop and go, hilly/curvy terrain, and constant shifting. My gears 2,4, and 6 clutch suffered failure from heat/condition related problems.

Any questions?

[kam327]

I posted this several weeks ago on a related thread. I'm reposting it here because it shows that the engineers know there is at least the potential for clutch overheat, so they built some protective logic into the software. I'm suggesting here that perhaps the clutches get hotter than they anticipated they would under certain types of driving.




Ford's objective is a transmission control strategy that warns while gradually trying to guide the driver from low-speed abusive operation into patterns that maintain reasonable clutch assembly temperatures for durability but without annoyance or causing noticeably poor driveability.

The warning levels start with "Transmission Hot-Stop or Speed Up" plus a warning chime. The message may repeat with a slightly louder chime. If heat buildup continues, the next message is "Transmission Hot-Stop Safely.

If there's no suitable change in driver technique and temperature of the clutch continues to increase, the computer can induce some shift shudder and then display "Transmission Hot-Stop. Wait One Minute" (or subsequently, the same message with more minutes). If the peak temperature level is breached, that message may be accompanied by the DSG going into neutral.

But multiple warnings and then shudder come first. Neutral only occurs when the temperature peak is exceeded, after the multiple warnings. So the declutching is always within a gradual sequence, never abrupt, Rich said. When clutch assembly temperature drops sufficiently, "Transmission Ready" is displayed.

With a properly functioning transmission, excessive heat buildup won't occur during normal or even aggressive driving, Rich claimed. Various forms of abusive low-speed/high-load operation, however, can heat up the DSG clutch. The most severe buildup occurs if the driver uses the gas pedal to hold the car on a relatively steep upgrade, or even creep slightly uphill at perhaps 2-4 mph
The objective is to induce the driver to apply the brakes, which disengages the clutch (producing neutral idle), cooling the clutch.

If the driver attempts to launch repeatedly in a 2-4 mph crawl-along and the clutch assembly is hot, the computer will inhibit launch to allow some cooling.

http://www.automotivedesign.eu.com/a...l-sensing.aspx

[dan50]

If I recall correctly, there is no direct measurement of clutch temperature. Instead, the software calculates what the temperature may be based on operating conditions. So, if the launch shudder is induced in normal stop and go traffic and not truly abusive situations (holding the car on a hill with the clutch, depressing both gas and brake at the same time, etc.), maybe it's still a software issue.

We all understand that cars aren't perfect and things go wrong. The truly frustrating part of this is that the dealer network, and maybe Ford itself, really doesn't know what to do about it.