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

[hotleadsingerguy]

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.

[Sponsor]

[bsp_53]

Interesting, mine is essentially acting like yours.
Since the TSB, once it has warmed up a little bit, she'll will shudder some in first gear. I'm @ 23,400 miles, so with a fair bit remaining on the powertrain warranty, I've been biding my time ... waiting / wondering if it will get worse. I'll go to the dealer again when it warrants it, but my sense is that they'll tell me the tranny is fine.

I've got to run some errand this morning, I'll wait 'till she starts to shudder and try your fix.

[smizak]

Originally Posted by hotleadsingerguy

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.

Very interesting. Will try and report back.

[hotleadsingerguy]

bsp_53, I'm close to 27k miles, so around the same boat. Give it and shot and let me know if it helps at all.

Smizak, Thanks! Maybe we can actually figure this out.

[TboneZX3]

Very cool--this looks promising! I hope this is a breakthrough for those of you with this annoying issue.

[hotleadsingerguy]

I plan on hitting the gas station down the street for a Monster at lunchtime (even though I'll be losing my prime parking spot and I'm actually getting lunch at work today)...so I'll let you know if it's still working fine with the TC off.

Also, we need a physical button or switch to enable/disable TC. I hate going through the dash menu for it.

[gkirk]

Originally Posted by hotleadsingerguy

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.

Could it be that with the wheel+tire combo you have, your call falls outside the diameter of wheel that the TC is expecting? My understanding is that the car expects a certain number of revolutions at a given speed, and if its not getting that number, the TC will start doing things.

I had a similar problem with my bimmer's traction control bc i had wheel+tires that were a bit too big (speedometer was off too).

It's just a thought.

Edit: Also the most recent flash for the DCT was also for the ABS/traction control. So maybe there is something at issue there.

[hotleadsingerguy]

Originally Posted by gkirk

Could it be that with the wheel+tire combo you have, your call falls outside the diameter of wheel that the TC is expecting? My understanding is that the car expects a certain number of revolutions at a given speed, and if its not getting that number, the TC will start doing things.

I had a similar problem with my bimmer's traction control bc i had wheel+tires that were a bit too big (speedometer was off too).

It's just a thought.

Edit: Also the most recent flash for the DCT was also for the ABS/traction control. So maybe there is something at issue there.

The tire and wheel combo is identical to the factory. The tires are actually the stock summer-performance tires, just put on different wheels. The wheels are a lot lighter (21lbs instead of 32lbs), but the dimensions are identical. I put my winter tires on the stock wheels so I could have good-looking black wheels for my summer tires.

Maybe that's the issue. I'm waiting for the regional customer service manager to call me back today so I can let her know the dealership did nothing, and I'll mention my testing as well while I'm on the phone.

It's funny...because I actually perform Quality Assurance as a career

[PratoN]

Originally Posted by gkirk

Could it be that with the wheel+tire combo you have, your call falls outside the diameter of wheel that the TC is expecting? My understanding is that the car expects a certain number of revolutions at a given speed, and if its not getting that number, the TC will start doing things.

I had a similar problem with my bimmer's traction control bc i had wheel+tires that were a bit too big (speedometer was off too).

It's just a thought.

Edit: Also the most recent flash for the DCT was also for the ABS/traction control. So maybe there is something at issue there.

Good point that the latest flash affected ABS, I forgot about that. I'll have to try this, but I doubt it'll solve my issue.

Also, I don't think the wheel size has much to do with TC/ABS as long as all of the wheels are the same size since it's checking for tires slipping and not revolutions vs true speed.

I could see lighter/heavier wheels causing issues if it's outside of the car's expected loads / parameters... that said, I think we're experiencing a leaking clutch seal (internal, most likely, since I have no fluids outside my bell housing as of yet).

[hotleadsingerguy]

Originally Posted by PratoN

Good point that the latest flash affected ABS, I forgot about that. I'll have to try this, but I doubt it'll solve my issue.

Also, I don't think the wheel size has much to do with TC/ABS as long as all of the wheels are the same size since it's checking for tires slipping and not revolutions vs true speed.

I could see lighter/heavier wheels causing issues if it's outside of the car's expected loads / parameters... that said, I think we're experiencing a leaking clutch seal (internal, most likely, since I have no fluids outside my bell housing as of yet).

Well that's my best assumption (the last paragraph). There's definitely a possibility of the TCU noticing lower resistance on the drive shaft and assuming that the tires are slipping when, in fact, the tires aren't losing traction at all. At that point it would engage the TC and feel generally as it does when the car "shudders". It makes perfect sense...but who knows if it's the truth.

As for the leaking clutch seal, that would only make sense if it just gradually got worse. My car was received in April of 2011, and I didn't have a single issue until after the TSB update that was performed in mid-June of this year. It started almost immediately after that point, got worse over the following 2 weeks or so, and then plateaued at that point and has stayed there ever since. It's almost as if the computer learned incorrectly and then held that programming.