Transmission shudder

[Bullett]

Hey guys, what if we have been looking at this in the wrong area?

A member from another forum did a write on this by pointing it in a different direction. Maybe some of you have seen it and some have not. This was a write up by Bluegrass on the f150forum.com

"Years ago I identified this kind of issue as being a faulty coil.
Here is the way it worked but is a bit complex to explain.
In higher gears above certain road speeds, EGR is commanded to open.
This adds exhaust gas back into the intake............Exhaust gas does not burn the second time but Leans out the air/fuel mixture for emissions improvement reasons.
Ignition timing is advanced as a result. Starting combustion earlier because the combustion process become faster.
Fuel is cut back. Improving fuel mileage and adding to Leanness.
The result is a very Lean air to fuel mixture over 20 to 1.
Under these conditions the mixture requires higher coil voltage to fire it.
If even one coil cannot provide that higher voltage, misfire occurs.
Under this special condition, no code is set because it's not a >hard< fault that comes and goes depending on driving conditions.
However: The misfire is recorded in another part of memory for each cylinder that it occurs in.
A tech needs to look at that mode 6 memory to see if there are any entries pointing to one or more cylinders that register over the acceptable limit set in program.
The cylinder/s may be suspect of having faulty coil/s and or boots.
Replacing spark plugs may fix the issue on a short time basis but the problem will come back as the plug tips erode and require more voltage to jump the gap due to the Lean mixture.
Another observation that may be helpful is to do a test drive with a Scanner attached and looking at ignition timing.
When the EGR is commanded to open, the ignition timing should advance a significant amount by design.
If misfires begin to occur the timing will go into retard as a result, to support the misfire. This adds to the feeling you get for drivability.
.
The above may or may not be your trouble but is worth a look at from this perspective.
You see how complex it can get and all the systems involved that affect the drivability and takes more than a simple look and thought.
The reason no code may be set is the misfire memory has no ability to set code because the program cancels the request if it in not in long enough to meet code set requirements,, so is cancelled.
Another thing that can happen is violent bucking from a faulty coil. When this happens the PCM can experience interference on the coil lead so much that program processing actually stops and starts for an instant then is picked up again.
The bucking feeling. It is picked up again because the Crank is still turning and Ignition is On, same as starting a motor would do.
.
The coil fault is shorted turns, not an open or a dead short that would become a hard fault and set a code on that cylinder. And no, the coil fault cannot be picked up with a resistance reading using a meter.
.
Please report the diagnostic results you see and if the problem was repaired by replacing a coil on an offending cylinder."

This is a video from a well known Ford tech on Youtube, explaining how to diagnose the issue when there is no DTC.

Oh man you got my hopes back up that there might be a fix… I have to take my truck in for an oil change soon. I might try a different dealer and ask them to look into this

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[Tsuga]

Oh man you got my hopes back up that there might be a fix… I have to take my truck in for an oil change soon. I might try a different dealer and ask them to look into this

We went for a long drive yesterday, we also noticed that there was a burnt match smell in the cabin when it shuddered under load. The smell is very similar to when our old f150 misfiring.

 

[sailorz]

For what its worth, I have had shuddering/hesitation issues with my EB since I bought it in March 21. I was seeing it in 9th gear 46-50 MPH and on moderate accelerations. I recently went through the process of forcing the software on the truck to update, and I can without a doubt say that it has improved the transmission's behavior. It is much smoother now with improved powerband gear selection and I dont have the 9th gear hesitation any more.

 

[swill]

For what its worth, I have had shuddering/hesitation issues with my EB since I bought it in March 21. I was seeing it in 9th gear 46-50 MPH and on moderate accelerations. I recently went through the process of forcing the software on the truck to update, and I can without a doubt say that it has improved the transmission's behavior. It is much smoother now with improved powerband gear selection and I dont have the 9th gear hesitation any more.

How did you force the software update?

 

[Fordphanatic]

The transmission in my truck with 3.5 ecoboost felt off for the first 1500 miles. Now it shifts nice through all gears. It was a little alarming the first few months.

 

[sailorz]

How did you force the software update?

If you look at your Sync software version and it shows blank, or if you go to Settings - System Updates and Automatic Updates are turned off and wont turn on, then you will have to manually perform an update to get it past the broken update.
See this thread for what it takes to perform a manual update.

 

[Tsuga]

The transmission in my truck with 3.5 ecoboost felt off for the first 1500 miles. Now it shifts nice through all gears. It was a little alarming the first few months.

What is your software version?

 

[mryan]

I have a 2021 Limited Hybrid Powerboost, the vibration is not just through the pedal. At times my cell phone will come off magnetic holder. 1500 rpm in 9th or 10th gear, slight acceleration or gradual incline. Been to two dealers now, first one replaced driveshaft and U joints. Next one shimmed pinion. The vibration is magnified when pulling anything, even an empty trailer with only 50lbs tongue weight. If you kick it down and have it shift to 8th gear it goes away, today I manually shifted down to 8th and of course it went away. It's like back in the day when we were all driving standards and forgot to downshift. Sickening for the cost of this truck, 3 previous Lariat's none had this symptom and 2 of them had the 10 speed transmission. 30,000km on it now.

 

[Bullett]

I have a 2021 Limited Hybrid Powerboost, the vibration is not just through the pedal. At times my cell phone will come off magnetic holder. 1500 rpm in 9th or 10th gear, slight acceleration or gradual incline. Been to two dealers now, first one replaced driveshaft and U joints. Next one shimmed pinion. The vibration is magnified when pulling anything, even an empty trailer with only 50lbs tongue weight. If you kick it down and have it shift to 8th gear it goes away, today I manually shifted down to 8th and of course it went away. It's like back in the day when we were all driving standards and forgot to downshift. Sickening for the cost of this truck, 3 previous Lariat's none had this symptom and 2 of them had the 10 speed transmission. 30,000km on it now.

My vibration gets worse when I tow my snowmobile trailer. It also does so in higher RPMs than when I'm not towing. Normally my shudder occurs right around 1500 RPM and is the worst in 8th gear. It generally goes away when I get above 15-1600 RPMs. While towing it shudders all the way from 1500-2500. It's so irritating to drive. Since December I've put maybe 700 miles on my truck and have been defaulting to my car whenever I have to go somewhere...

 

[Tsuga]

I have a 2021 Limited Hybrid Powerboost, the vibration is not just through the pedal. At times my cell phone will come off magnetic holder. 1500 rpm in 9th or 10th gear, slight acceleration or gradual incline. Been to two dealers now, first one replaced driveshaft and U joints. Next one shimmed pinion. The vibration is magnified when pulling anything, even an empty trailer with only 50lbs tongue weight. If you kick it down and have it shift to 8th gear it goes away, today I manually shifted down to 8th and of course it went away. It's like back in the day when we were all driving standards and forgot to downshift. Sickening for the cost of this truck, 3 previous Lariat's none had this symptom and 2 of them had the 10 speed transmission. 30,000km on it now.

I take it you still have the issue. The dealer I went to, thought it was the driveshaft also. They did not find anything on the driveshaft other than some undercoat over spray. Needless to say, I will drop the truck off when the parts for the heat shield recall are in.

 

[mryan]

Yes I still have the truck, it went to the dealer yesterday for further troubleshooting. U Joints and driveshaft replaced months ago. Issue no better with 30,000km on it.

 

[Tsuga]

Yes I still have the truck, it went to the dealer yesterday for further troubleshooting. U Joints and driveshaft replaced months ago. Issue no better with 30,000km on it.

Let me know if the have a solution. Where are you in Ontario?

 

[mryan]

Kingston area. I’ve asked for the truck back. I leave for West Virginia on Thursday and don’t need them messing it up. I suspect Ford knows well about this issues, if they fixed it, it will mess up their EPA ratings and they would be in the mess VW was a few years ago.

 

[Tsuga]

Kingston area. I’ve asked for the truck back. I leave for West Virginia on Thursday and don’t need them messing it up. I suspect Ford knows well about this issues, if they fixed it, it will mess up their EPA ratings and they would be in the mess VW was a few years ago.

This makes sense, but if it is the case, wouldn't all of the Ecoboost engines have the same issue with the software programming?

 

[mryan]

A lot of these trucks never pull anything so they may never notice. I agree with you though, my 2020 Lariat never exhibited these symptoms. The burning candle I have witnessed as well and had hoped it would catch fire. To me that smell is a fuel issue.

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