Powertrain Vibration --3.5 L Turboboost operation

[Thunderchief]

I am asking the community for information on the Turboboost operation. I have a 2022 Lariat with the Powerboost hybrid set up. I notice that when climbing a fairly long and steep mountain (I live in the North Carolina mountains) at about 55-mph using Cruise Control, I will periodically get a shudder/vibration in the power train. Most of the climb the transmission stays in one of the overdrive gears and mostly 10th gear. I have been trying to determine what is going on when I get the vibration and I have noticed the boost pressure fairly quickly rising and dropping coincidental with the vibration. Hence my question, what tells the turboboosts to start, how is it controlled, and what are the parameters for starting and stopping the boost.

I have seen a number of comments on the site about powertrain vibration and I thought it had to be something with the transmission. However, my transmission is fairly steady, no shifting, when my vibration comes and goes but the pressure on the turboboosters seems to coincide with the vibration. It may be a normal vibration when the turbines are functioning.

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[CptBligh]

No idea on specifics, just adding my observations but the 3.5L seems to be programmed to increase boost rather than down shift the transmission whenever possible. The low RPM and high torque load is what leads to the engine lugging/shuddering IMO. I lock out 10th gear until I'm over 60mph and 9th until 50 depending on traffic conditions. My Expedition exhibits the same behavior as well. Not sure what the point of 10sp trans are and then refusing to use all the gears but I guess then some people complain of constant shifting.

And cruise control has always annoyed me on anything but extremely flat ground.

 

[Thunderchief]

How do you lock out 10th gear?

 

[CptBligh]

How do you lock out 10th gear?

While in Drive, press only the - button on the shifter. Each press will lower the highest gear allowed. + to raise them back up. The gear numbers will disappear on the dash gauge as you change it. It will reset to normal if you shift out of drive.

 

[Thunderchief]

How do you lock out 10th gear?

Don't you have to be in the "M" mode before these buttons work?

 

[CptBligh]

Don't you have to be in the "M" mode before these buttons work?

Pressing M first will just enable manual shifting.

Pressing the -/+ alone just acts like a gear limiter, it will still shift up and down the range that you allow like normal.

 

[Thunderchief]

That is interesting. I took my truck out on the Smoky Mountain Expressway and set the cruise control for 55 mph. The transmission was in "auto" and settled on 10th gear. I pressed the "+" and "-" buttons several times and nothing changed. It stayed solid in 10th gear.

 

[Oxford_Powerboost]

I’m not sure when your 22 was built, but there is a service bulletin from ford on this issue. TSB 22-2224 shudder at highway speeds when accelerating or climbing a hill in gears 8, 9, and 10.

There is a fuel trim issue in the powertrain control module that makes it shudder when boosting in overdrive gears. The fix in the TSB is to reprogram some modules in the truck. I had it done on my ‘21 Powerboost and the shudder is gone and the transmission downshifts more often when climbing now.

 

[Snakebitten]

I mean no offense but F150's have been equipped with the ability to "lock out" gears for better than 11 years. Both the 6R80 and 10r80 transmissions have the +- button for exactly this reason.
This feature is not just for driving the truck in manual mode.

The instrument cluster shows all the gear ratios currently available and highlights the gear ratio that the transmission is currently in. As stated above, each press of the - button removes the highest gear ratio currently available.

This is absolutely intended for the driving conditions described. Low RPM's High Load. That's really hard on the drivetrain for extended period of time. A couple of clicks on the - button is equivalent to saying "Alexa, 8th gear please"

These are amazing trucks. But the oem shift strategy isn't necessarily a good thing in all circumstances. Fortunately our modern trucks have multiple shift strategies (driver mode select) and buttons at our fingertips to intervene for temporary circumstances.

In my opinion 10th gear at 55mph is brutal on a motor like the Ecoboost unless your flat landing and no wind. But I personally would either lock out 9,10 or use a different shift strategy like Sport. The problem with Sport Mode is Ford actually takes the silly label "Sport" way too far and disables EV cruising just to sell the label. It's just a different shift strategy. You don't have to drive aggressively just because the name for the strategy is Sport. Lol

I love Ford trucks. But they make some crazy design decisions that make no sense sometimes.

 

[powerboatr]

I mean no offense but F150's have been equipped with the ability to "lock out" gears for better than 11 years. Both the 6R80 and 10r80 transmissions have the +- button for exactly this reason.
This feature is not just for driving the truck in manual mode.

The instrument cluster shows all the gear ratios currently available and highlights the gear ratio that the transmission is currently in. As stated above, each press of the - button removes the highest gear ratio currently available.

This is absolutely intended for the driving conditions described. Low RPM's High Load. That's really hard on the drivetrain for extended period of time. A couple of clicks on the - button is equivalent to saying "Alexa, 8th gear please"

These are amazing trucks. But the oem shift strategy isn't necessarily a good thing in all circumstances. Fortunately our modern trucks have multiple shift strategies (driver mode select) and buttons at our fingertips to intervene for temporary circumstances.

In my opinion 10th gear at 55mph is brutal on a motor like the Ecoboost unless your flat landing and no wind. But I personally would either lock out 9,10 or use a different shift strategy like Sport. The problem with Sport Mode is Ford actually takes the silly label "Sport" way too far and disables EV cruising just to sell the label. It's just a different shift strategy. You don't have to drive aggressively just because the name for the strategy is Sport. Lol

I love Ford trucks. But they make some crazy design decisions that make no sense sometimes.

me to
i have found unless its flat and i am doing at least 70 . i lock out 10

on my 60 mph farm road its locked to hold 8 or lower

if i select SPORT it will hold 7 th and not up-shift until i am near 70 or 75 depending on GO pedal pressing distance to floor
3.31 gears are just a bit to high for 10th unless your getting it on the highway.

and i have found SPORT mode is actually getting me better MPG around town (45-60mph)
i am up to 18.7 yipppppeeee

 

[wilmaj32]

Good Luck! Ive been dealing with this issue for over a year. My truck has been in the shop 4 times for a total of 31 days. They tell me its normal. You'll have guys on here that apparently don't have the shuddering issue tell you to stop complaining and its a "learning transmission" Do a search, there are hundreds of entries on this topic. I'm in the beginning stages of a Lemon Law claim.

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