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Think I figured out the shuddering when starting from a stop...can't believe it

66K views 401 replies 94 participants last post by  narkotskyb 
#1 ·
So I've had more issues with the shuddering than I could even explain, and it all started with the TSB for the transmission update. Since that point, it's shuddered mostly every time I start from a stop. It's obnoxious, and makes the car feel cheap and crappy when people are riding in it. I've had it in the shop probably 3-4 times for this issue and every time they've said "It's supposed to act like that" and that the computer displays no errors.

So what did I do today? Turned off Traction Control. The second I turned it off, the shuddering from a stop no longer happened. I drove my 15 minute commute to work without a *single* shudder. The shifts were smooth, the starts and stops were smooth, and even mashing the gas when going into a corner from a stop or slow roll didn't make the car buck around like it was having a stroke.

Turn it back on? And the shuddering happened the very next light. Turned it back off, and no more shuddering.

Is it possible that this issue is somehow related to the Traction Control module initiating when it doesn't need to? I have lighter wheels on the car than stock (Sparco Assetto 18), but didn't have an issue with this until the TSB update. The lighter wheels might fool the computer into thinking it's losing traction (since there's less friction and resistance on the drive shaft), but I really can't postulate an answer beyond that.

For those of you with "Shuddering" issues, please help me test this by just disabling the Traction Control and driving like you normally would. If it's gone (or at least severely reduced), post back and let me know. Maybe Ford needs to issue a recall for the *CORRECT* part in the car this time.
 
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#53 ·
wish there was a fuse we could pull to disable it. lol.

I bet there are all kinds of hidden access to things like hold the gas pedal down, press the brake 3 times then roll the rear passenger window down and it will open the Advanced settings menu. LOL.

Thats just a joke!. but Im sure there are things like that in most cars.

I would love to find something like that in the MFT system.
 
#55 ·
I was all exited about this ''possible fix'' when I read about it today. So upon gettin my hands on my car at the end of my shift, I did the 7 step procedure to deactivate the TC (The damm engineer that buried this feature so deep does not deal with snow banks 6 months a year, that's for sure) and...no cigar...

The car/tranny still behave like a lardass. There is still the same amount of shudder, the same amount of ''lag'' when in motion and trying to get some speed quick, the same loss of power when taking a 90 degree turn and the same amount of insane over reving when trying to get some speed quick.

I know you guys are talking about the shudder thing, but I was kinda hoping it would also resolve the sh!tty tranny behavior I have. Saddly not. I'll keep looking into it. If some of you guys can find some peace and joy with this, I'm happy for you all.

Cheers
 
#57 ·
Do you have the 12B37 update?

I do not but I also have no issues with the clutch/transmission.
For me, TCS on or off makes no difference in "smoothness".

In your case, perhaps a clutch replacement is the answer (possibly because of leaking seals).
 
#63 ·
Much better with TCS off

Here is what I noticed while specifically going through all situations I complained to dealer b4:

1. I can EASILY modulate engine response while in 6th gear when driving on the hilly highway.
2. Shifts are much quicker 1 to 4 when going from the dead stop
3. Downshifts ARE SO MUCH better from 6 to 5
4. I an easily modulate throttle for constant speed uphill with variable grade.

In my case I think we've got a winner. No only if Ford will tell me wtf is wrong with TCS/AdvanceTrac. Thought it suppose to help you not handicap you?

For everyone out there I would definitely suggest doing it then drive around some good hills
 
#64 ·
TCS off greatly improved the shudder and clutch slipping when taking off from a stop for me. Since 12b37 this problem has been seriously annoying but havnt brought it in to service dept yet. Now with this TCS off the car is much better to drive. Before 12b37 the car was perfect shifting gears, almost seamless shifts and I never turned TCS off before either.

IMO its not the TCS that's flawed; its the software update 12b37 that caused it. A new update should fix it or if Ford would let us roll back to the previous DCT update that would work too. Hoping this find will help them to get us a fix soon!
 
#70 ·
Well, drove home with it off and drove back to work with it off today...not one instance of shuddering. There's a *tiny* bit of clutch slip on takeoff, but that I would expect (same as any manual car)...and it's *GREATLY* reduced from when I have the TCS enabled.

My theory is thus: one of the factors used in determining whether TCS should be engaged is the resistance on the drive shaft. When there's far less resistance than the computer thinks it should have, it engages the TCS to even it out. I'm using lighter wheels (21lbs as opposed to 32lbs stock wheels), so maybe I'm more at risk since there's already less resistance. Maybe I'm passed the tolerance of the computer and so the computer thinks the TCS should be engaged. This all makes sense since the shuddering *does* feel like it's being created artificially by the TCS.

Also, the TCS doesn't just use the ABS to control tire movement. Traction Control can encompass more than just sitting on ice and revving the engine. It controls tire movement through the use of the braking, torque vectoring, fly-by-wire fuel management, and good old-fashioned clutch control. That means when it thinks the tire is slipping it might employ the brakes, it might put more torque on the opposing side, and/or it might cut the engine a bit and disengage the clutch to some degree.

All of those factors together can easily account for shuddering. It's just amazing that not a single Ford engineer has figured this out before now. Good thing I have a phone call with a corporate engineer tomorrow :) Hope he know more about dry concentric dual-clutch transmissions than the last one.
 
#71 ·
Well, drove home with it off and drove back to work with it off today...not one instance of shuddering. There's a *tiny* bit of clutch slip on takeoff, but that I would expect (same as any manual car)...and it's *GREATLY* reduced from when I have the TCS enabled......
This is good info but I don't think it explains for a lot of folks, including me a while back, why the shuddering starts happening only after 20 mins. or so of driving, or coming off an expressway after a longish trip. In other words, when the tranny is hot. I've seen several of the shuddering compainers say that it only starts after driving for a while.

Nor does it explain why my shuddering completely went away on its own. Unless the TCS logic also 'learns' and adjusts over time. So it may be an answer for some, not for all.
 
#72 ·
I thought traction control systems compared the rotational speed of the drive wheels, not torque, to identify slippage. It would be great if the TCS was the reason for our maladies but I can't quite get clear in my mind why it would be so. It makes sense for those who complain about odd behavior in a 90 degree turn (as drive wheel speeds would be different), but a straight-ahead start?

On the other hand, while my transmission behaves acceptably, to me it feels like the timing retards under low-speed acceleration, resulting in poor throttle response and a surging sensation. As traction control systems can use brakes, throttle and timing changes to deal with a spinning wheel, maybe this is really the cause. I'll give it a try later today.
 
#75 ·
It might be a latency issue as well, which could explain why responses might be better with TCS turned off. Basically if the different computers need to talk to each other, there is a delay when signals and messages are sent back and forth, answers computed and sent back.

If you have say 3 computers doing this, it is easy for a small lag on two of them to cause a huge bottleneck for the whole system, as components hold up their computations waiting for answers from each other.

So what i wrote is pure speculation, but it would make sense that if one of the main components is just turned off, the remaining ones don't worry about it and do their own thing. Lag is gone.

Terms: Latency: this is the lag of a message going from one node to another. For example if a packet of information is sent from one component to another, it might take .1ms to get there. It doesn't matter what else is happening, this latency will always be there. If that packet is the computed on and sent back, another .1ms of latency is added to the total round trip, plus whatever the computation time took. Depending on how communication is set up between components, you might have many rounds of latency to take into account (which would appear as lag).

gk

Edit:
On my drive, the car seems smoother and slightly more responsive with TCS turned off. I need to test it more to be certain. Also, the car handles wet quite corners really well with TCS off :). I wasn't sure if it was using the stability control stuff on corners all the time or not.

If anyone wants an explanation of why 3 computing devices can slow down a lot under certain conditions that won't happen when there are just two, I can do that. lol. wikipedia does it better than I can. :)
http://en.wikipedia.org/wiki/Deadlock
 
#77 ·
I don't have a stutter issue, but what I noticed was that it seems to have less resistance to accelerate, and my mpg increased from 33.7 to 34.3 over 60 miles starting at 250 miles into the tank so it should have been stable by that point.
 
#78 ·
A big thank you to everyone who is posting their experiences with traction control! [thankyou]

If you're still having issues, please send me a PM so I can help out. All I need is your VIN, mileage, dealer, and daytime phone number; I'll get to work!

Thanks again,
Crystal [wave]
 
#81 ·
Confirmation ... my 1st gear shudder is non-existant with the traction control disabled. When it is turned back on, 1st gear shudder returns. Verrrry interesting, I'm somewhat excited to find out where this all ends up.
 
#85 ·
Occasionally my car has the first gear shudder when accelerating from a complete stop. I have been running with my TCS off since yesterday (after reading this thread) and have had zero shudders. I did a lot of stop and go running my daughters around so I would say it definitely is making a difference. My car is a March 2011 build with 35,000 miles.
 
#86 ·
#87 ·
I can't wait to try this on my way home from work today. I will get the shudder after driving 25 miles on the PA Turnpike and get off at the Bensalem exit where we cattle-chute down from 10 lanes to 1. When I'm maneuvering into the lane and stopping and starting is when I ALWAYS get the shuddering.
 
#100 ·
Our brilliant in corners torque vectoring system is what causes this, so our front differential isn't like most FWD cars.

I can attest to better smoothness when TCS is off and more smoothness in general when I'm changing on my own
 
#104 ·
What exactly does TC do? Is it just for controlling wheel spin while driving like on snow and ice or is it what other manufactures call vsc? (vehicle stability control). Which actually controls the braking on each wheel independently to prevent loss of control. i.e hydro planning etc.

If TC is strictly for wheel slip. I could care less and would welcome a way to disable it.
 
#105 ·
What exactly does TC do? Is it just for controlling wheel spin while driving like on snow and ice or is it what other manufactures call vsc? (vehicle stability control). Which actually controls the braking on each wheel independently to prevent loss of control. i.e hydro planning etc.

If TC is strictly for wheel slip. I could care less and would welcome a way to disable it.
As far as I know, just wheel slip. TC and electronic stability control are separate. I like Thegonagle's response on this site: http://www.city-data.com/forum/auto...ic-stability-control-vs-traction-control.html
 
#111 ·
^ That is verbatim from the TSB. That said, if your transmission is making weird noises (not just shuddering) I think that's something your dealer should still be fixing under warranty - TSB or not.
 
#112 ·
My car does not have the transmission problem that some on this thread have been experiencing but I'd thought I should try turning off the traction control just to see what would happen anyway. After driving my car in rush hour traffic yesterday for almost 45 minutes, driving as slow as 15 MPH and as fast as 45 MPH, my car exhibited no significant difference in its driving experience, i.e. I still have not experienced the phenomena that others have experienced with their tranny.

The build date on my car is 8/11 so its fairly old but not as old as some of the other folks' cars who have been experiencing issues but who knows if that is a factor.
 
#113 ·
Mine was built 03/11, and has not experienced any issues.

It will sometimes shudder, which I believe to be normal. It typically happens when I'm not deliberate with the throttle, or when I shift at incorrect times (I also typically use select shift).

I also do not have the most recent gearbox update.
 
#115 ·
Wow, very interesting read. Happy that you guys seem to have found the issue, but it's sad that the "fix" is such a constant inconvenience (turning it off every time). To me, this really sounds like this needs to be looked into by Ford. So many people with similar results can hardly be random.

The fact that one feature of the car severely hinders another is not acceptable and could even be considered dangerous. The choice between having transmission issues and having no traction control is not a choice one wants to make with a car that is supposed to have both working.

I'm curious to see what the corporate engineer has to say about this...
 
#117 ·
That's precisely the problem -- Ford says "This is the way the car is meant to operate" and leaves it at that. They don't listen to reason or logic beyond and including that statement, so getting them to change it will be downright impossible unless they realize it themselves.

I have a conference call today with one of the "Corporate Engineers" (read: not really an engineer at all) to discuss my issues with the transmission. Having driven more than 15 concentric dry dual-clutch systems across various platforms I feel I have a fairly strong understanding of how this transmission *should* operate. We'll see if I'm able to make my case, or if I get the same old "We know what we're doing" speech.

If I do, the options are either that they buy it back or I bring up a lawsuit. I'm done messing with this car after they drastically changed the operation of it without my approval. I didn't buy a $30k that drives like this, and I'm not going to be expected to keep it for 10 years in this condition.
 
#121 ·
Good morning!

I want to start aggregating the information of people who are happy with their vehicle's performance after turning off Traction Control. Please send me a PM with your VIN and also let me know if you've had TSB 12B37 applied.

Thanks!
Crystal [wave]
 
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