Shudder/Jerking Issue When Accelerating
 

I have a 2021 F-150 STX 4x4 with the 2.7 and 10 speed transmission. I've been having an issue with a shudder or jerking feeling when I'm on the interstate at higher speeds when accelerating between 1500-3000 rpm. It does this a little bit in all gears but it’s a lot more noticeable at higher speeds where the gears don’t have as much torque. You can feel it the most on the interstate when the truck is in cruise control as you go up hills or accelerate to pass someone.The issue can easily be replicated by setting the transmission to manual shift and lightly accelerating under the following conditions-

- 8th gear with the truck moving 65-80mph

- 9th gear with the truck moving 70-85mph

- 10th gear with the truck moving 75-85 mph


The truck currently has around 10k miles on it but the issue started around 5k miles and has gotten worse since then. When I put larger tires(35") on the truck, the additional load made it more noticeable and when I’m pulling a trailer or my boat it’s a lot worse. I’ve tried different octane fuels at many different gas stations and it doesn’t have an effect on the issue.

I've taken it back to the dealership and they're telling me they can't replicate the issue and theres no error codes so they don't know what to do.

Any suggestions of what could be causing this? Or next steps I should take to escalate this above the dealer to ford?

Thanks

I feel like I remember seeing someone else have a similar issue as this and they fixed it by doing the throttle body relearn procedure.

Interesting.. I couldn't find the procedure that specifically said its for a 2021 but I did the one below. I haven't got on the interstate yet but I'll see if it helps in the morning.

https://www.vehiclehistory.com/quest...ocedure-131530

Interesting enough my truck is sitting at the dealership since last night for the exact same issue. They called me today and gave me the “it’s normal” speech for the transmission and there is nothing they can do, I suggested a reflash as well but they won’t do it as there is no bulletin from Ford. I did read elsewhere the ten speed transmission is common for this to occur.

it truly is frustrating as the transmission is really shaking, like a misfire, unless you really hammer down on the gas to get to higher rpms.

my truck only has 4400km, 2.7 eco also….

I forgot to mention that this is a pretty known issue as well that these trucks have due to Ford trying to squeeze out every last inch of MPG. Typically a lot of us lock out higher gears in certain scenarios.

I'm not convinced its a transmission issue on mine though. I start to notice it when the RPM is around 1500-1700 when you can start to hear the turbo.
I've noticed it all the way down to 3rd and 4th gear just slowly cruising through the neighborhood. Locking out gear wouldn't work for me though because at highway speeds it does it from 7th-10th gear.

I’ve been experiencing the same issue since 400ish miles and I’m at 5k now. I’ve been to the dealership multiple times to try and rectify the issue and Have been told it’s normal. Have another appointment on the 12th of October to look at it again. Hopefully if I complain enough they’ll do something. My truck feels like I’m driving over a rumble strip between gear 8-10. It’s most pronounced in 9th gear though. If I make any progress I’ll come back and provide an update

slow pick up speed issue
 

Hello everyone,

I have a F150 2014 145,000 km on clock, recently I've changed Air filter, Spark plugs but already I have an issue with speed pick up. It doesn't go further than 120km/h since I used to drive 180-200km/h with the same car.
I already googled and realized that there is longtime life fuel filter in this car, what should I check to fix this issue?

I did the relearn process last night and tested on the interstate today but that didn't help.

I don't think this is related but my transmission temperature gauge rarely works either. 95% of the time it stays on the "C". Could it be possible that the ECU thinks the transmission is cold and causing it to run different? Does anyone else have a temp gauge issue?

I'm sorry to hear that the relearn process did not work. As far as your transmission temp unless you're really working the trans hard like towing or something it may not reach the middle of the gauge. Mine usually runs pretty cool too especially with the trans cooler on it. I think in the 13 gen's they added an option to have the temp displayed in number form over top the gauge. I wonder if yours has this option? I have a 12th gen so I may not be of much more help to you.