Shudder/Hesitation when cruising in 6th gear/Low RPM

[dubcitySHO]

I will have to drop Brad another email perhaps on this issue.  If he can tune out some of the tendency for the engine to lug without downshifting it may help.  At least with my vehicle it def seems like that's when it's most prevalent. 

[FoMoCoSHO]

Another option would be to pull that left lever when you want to accelerate since in D it will return to normal shift schedule without further input.

Obviously not a fix but it is a simple workaround till someone figures it out.

[dubcitySHO]

Another option would be to pull that left lever when you want to accelerate since in D it will return to normal shift schedule without further input.

My paddles are non functional in D on my '12 although the '13+ guys will benefit.  I have bumped down into M and used them to keep RPMs up in certain situations though.

[sholxgt]

Another option would be to pull that left lever when you want to accelerate since in D it will return to normal shift schedule without further input.

Obviously not a fix but it is a simple workaround till someone figures it out.

With the stock tune, I can put it in S mode and live with the higher rpm and lower fuel economy that comes with it to avoid the 6th gear stutter because it only occurs below about 60mph.  If tuned, the range of stutter expands too much for that to be an option.  It stutters even when accelerating at 70+mph on the interstate. 

At the beginning of each of the logs below you can see the parameters that are funky during the stutter.  Note the rpm variation and torque converter functions.  Boost included to show that I don't believe it is related to the issue.  Other motor functions appear normal as well.  I believe mine to be converter related.  The solution is likely a new torque converter, but I don't know how to get a dealer to spring for one.

Note that when the converter goes to 100% lock, the rpm variance diminishes greatly.








That all being said, I'm not 100% positive that it's the torque converter.  The thought of it possibly being LSPI from boost coming in at such a low rpm with the onset of load seems to be a possibility as well and would explain why the car is worse tuned than it is untuned. 

[Vortech347]

Another option would be to pull that left lever when you want to accelerate since in D it will return to normal shift schedule without further input.

Obviously not a fix but it is a simple workaround till someone figures it out.

The problem I ran into when doing this is the transmission would go back into 6th. So I had to lock it into sport on the big hills.

[FoMoCoSHO]

Another option would be to pull that left lever when you want to accelerate since in D it will return to normal shift schedule without further input.

My paddles are non functional in D on my '12 although the '13+ guys will benefit.  I have bumped down into M and used them to keep RPMs up in certain situations though.

Good to know. I'm contemplating buying a used gen 4.1 and going crazy with it so I'm trying to figure out what I will lose going backward.

[SHOdded]

I don't think the car will be the issue.   The amenities, sure.

[derfdog15]

Another option would be to pull that left lever when you want to accelerate since in D it will return to normal shift schedule without further input.

My paddles are non functional in D on my '12 although the '13+ guys will benefit.  I have bumped down into M and used them to keep RPMs up in certain situations though.

Good to know. I'm contemplating buying a used gen 4.1 and going crazy with it so I'm trying to figure out what I will lose going backward.

I don't think this annoyance in drive ability will be a major concern if you're building an all out drag/track car since you won't be worried about street manners.

I didn't realize on 10-12 you couldn't use the paddles in D. I wonder if that is something that can be added in with a custom tune?

[dubcitySHO]

Another option would be to pull that left lever when you want to accelerate since in D it will return to normal shift schedule without further input.

My paddles are non functional in D on my '12 although the '13+ guys will benefit.  I have bumped down into M and used them to keep RPMs up in certain situations though.

Good to know. I'm contemplating buying a used gen 4.1 and going crazy with it so I'm trying to figure out what I will lose going backward.

I didn't realize on 10-12 you couldn't use the paddles in D. I wonder if that is something that can be added in with a custom tune?

It may be possible as Brad added the hold gear feature so it won't downshift automatically when WOT in Manual mode on mine.  I no longer have to roll into the throttle for the datalogging sessions from a roll.  Just hammer down and feel that TQ build.

[SHODRVR]

Having the exact same issue with mine non pp SHO. I bought the car used and have had the issue since day 1. I also daily drive the vehicle mostly highway and feel the shutter at all speeds but always on 6th. It super annoying to say the least. I have brought it the the dealer 3 times for the issue and they say they cant get the car to do it. Thats with me taking the service manager out for a drive and telling him the car is acting up and him telling me he doesnt feel the issue. I even pointed out the wandering rpms the up and down shutter bounce it does. Seems like the dealer doesnt want to help fix the issue. I will hopefully be trying out a new dealer this week for the issue. I have 10 k left on the powertrain warranty so if its a PTU issue or TC issue i need it fixed now.

[curry67]

when was the last time you changed the plugs? this sounds alot like what my car does when it blows a plug. it was always around that rpm. didnt cause a problem till i gave it gas or luged in a high gear.

[Vortech347]

Mine has now started to do this a little bit when I'm around town low RPM in 4th gear.  The car has 33k on it now so I'm going to plan on doing plugs in the spring.

[dubcitySHO]

Its been awhile since this thread has been active, but thought I would update on my situation.  My car (MY-2012 SHO) was experiencing the same issues and my culprit was the torque converter.  Had a Ford reman torque converter installed and all symptoms disappeared completely. 

The following link is the part I used, and had the opportunity to tear into the PTU while the garage had the transmission out.  Everything seemed to be in good mechanical condition, with only minor material on the magnetic fill plug.  The fluid was in decent condition as well, no sludging but was pretty dark.  Did not keep any samples for UOA, perhaps not a good call, but to late now.  I'm going to give it 5000 miles and am going to have the shop drill and tap a drain plug for future PM of the unit.

https://www.buyfordpartsonline.com/oem-parts/ford-reman-converter-asy-aa5z7902brm

Hope this helps anyone else experiencing the same issues!

[pmezo33]

The TC seems to be a very weak spot with these transmissions. 

[dubcitySHO]

Seeing as more and more people appear to be falling victim to this problem I agree.  Hopefully this new part lasts at least as long as the factory original