Truck "bucks" at slow, steady speeds

[NvrFinished]

Well, I've come back to this thread after experiencing similar symptoms. I really noticed it when driving in slow traffic on the freeway that wasn't quite stop and go. In the 25-35 MPH range, it seems like the truck bucks/lurches a little or is hunting gears. It happens occasionally in steady driving in this range as well.

I'm 1500 miles from the end of my warranty. I think I will replace this first before taking it in.

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[NvrFinished]

Glad you finally got it fixed right and a new TC out of it too. lol I ordered an EGR valve to have on hand as it seems imminent this WILL happen soon. They're on national back order but should be off by next week.

Do you happen to have the part# handy for this?

 

[AzScorpion]

Do you happen to have the part# handy for this?

I certainly do. ?
LB5Z-9J433-B

 

[NvrFinished]

I certainly do. ?
LB5Z-9J433-B

Awesome, thanks!

 

[Yikes1961]

At 51k, could it be your plugs are showing signs of age? I've heard others replaced them at 50k.

I just had 4 plugs replaced at 45,xxx I really don't think that was the issue. Repair was done at a Ford dealership. it was "stuttering" fairly bad at that time, but it is still doing it now, but not as bad. I took it into my local highly respected repair shop this week, to see if they can diagnose it correctly. Will let you know if they find out anything.

 

[FX4Offroad]

Pict from the invoice

 

[Kingmm]

Thank you! I will give it a try.

 

[Kingmm]

Thank you FX4Offroad. Part KA1Z-5L200-A (EGR flow sensor) did the trick. Runs like brand new! For those of you who have not tried this, it worked. The hose clamp system is an 'ear clamp' system. You will need the ear clamp crimping tool (get the dual front and side jaws), ear clamp cutting tool (for removing the old clamps), and a variety set of the ear clamp rings.

 

[Yikes1961]

soooooo.......after taking my truck in to possibly get the injectors replaced, the dealership said that wasn't it. After taking a test drive with the Serv Mgr, he mentioned another person with a Ranger had had the same problem, and that they got a torque converter for his truck. I suggested that they order me one (they were on super back order for the other guy) so that way when I have (not if) more problems they will have it in stock.

This morning I was complaining to the husband that I was about done with this Ranger due to the stuttering. He said that a guy at the store asked him how he liked his Ranger, and after being told about the stuttering, and guy said he had the exact same problem with his Tacoma.

Long story short, Ford called this morning and said my torque converter was in and scheduled an appt. Warranty repair. That was coincidental!! Fate at work here.

 

[VegasRanger]

I replaced my EGR thing too. Made a huge difference. Best $25 spent on this truck.

 

[troutspinner]

soooooo.......after taking my truck in to possibly get the injectors replaced, the dealership said that wasn't it. After taking a test drive with the Serv Mgr, he mentioned another person with a Ranger had had the same problem, and that they got a torque converter for his truck. I suggested that they order me one (they were on super back order for the other guy) so that way when I have (not if) more problems they will have it in stock.

This morning I was complaining to the husband that I was about done with this Ranger due to the stuttering. He said that a guy at the store asked him how he liked his Ranger, and after being told about the stuttering, and guy said he had the exact same problem with his Tacoma.

Long story short, Ford called this morning and said my torque converter was in and scheduled an appt. Warranty repair. That was coincidental!! Fate at work here.

I have not read this thread from the beginning but if you have not replaced the EGR yet, I highly suggest doing so before letting them tear into your truck. Too simple to overlook and the change in behavior is immediately noticed.

 

[Yikes1961]

I have not read this thread from the beginning but if you have not replaced the EGR yet, I highly suggest doing so before letting them tear into your truck. Too simple to overlook and the change in behavior is immediately noticed.

oh it's been done lol
We've had the truck for 3 years now (bought used) and that was the first thing done.
then replaced the spark plugs about 4 months ago, that's what they thought was the problem at the time, too.

 

[Shoran12]

I have a 2020 Lariat FX-4 with around 6100 miles on it. I'm about 5 miles from work and most of my drive is in the 25 - 35 MPH range.

You probably don't have anything wrong with your transmission.

FORD NEEDS TO REPROGRAM THE TRANSMISSION SHIFT POINTS AT SLOWER SPEEDS!!!

Something you can try. Put the transmission in DRIVE and push the the manual shift button on the side of gear shift stick up or down. You'll see on the right display what gear the transmission is in (this will not shift the transmission unless you're in MANUAL). When I'm going around a steady 30 mph; the transmission on my truck goes to 7th gear (too high for this speed in my opinion). This is more than likely why you're also having that bucking feeling. The RPM drops too low and the transmission will not shift down unless you accelerate. The only thing you can try to stop the bucking feeling is to put the transmission in MANUAL and shift to 5th gear (or maybe 6th gear at the most). The engine will run around 2000 RPM and you'll be around 30 - 33 MPH. Put back in DRIVE when slowing to stop or manually down shift and repeat. Yes, this shouldn't need to be done and is a royal pain in the @$$. Something else you'll notice is the transmission will shift from 1st to 3rd gear under normal acceleration skipping 2nd gear.

Hope this helps ?

Have just over 3000 miles on mine and this is exactly what my transmission does. It’s worse up slight hills where I get a shudder and look at rpm’s and transmission gears and notice I’ll be in 7th going 30 up a hill. Blows my mind that Ford wouldn’t test this out first and decide to change the shift points a bit. Hoping this smooths out over time. I think I may try to drive it as is in hopes the computers will realize they’re about to stall the engine out and make adjustments. Just my unfounded hope though lol.

 

[Shoran12]

My truck does this as well but only in my neighborhood(25mph) going up hill. I currently have a brand new loaner from FORD due to the blend door failure on my truck and it also does this same thing in same spot every time, vibrates/bucks more in the loaner IMO. I also had the TSB done on my truck at 12k miles.

My Truck:
2019 2WD XLT
21,500 miles
Stock(except the damper )

Loaner Truck:
2022 4WD Lariat
120 miles
Stock

Glad it’s not just me. My 22 STX gives me a rumble strip vibration on slight inclines when I’m in 5th - 7th going Around 25-30. Rpm’s drop to 1300. Only way to make it go away is give it more gas. Makes it very hard to drive the speed limit in these situations. I can make the ruble go as long as I want if i don’t change throttle pressure. Hard to believe this is normal but guess it is.

 

[pbethel]

Glad it’s not just me. My 22 STX gives me a rumble strip vibration on slight inclines when I’m in 5th - 7th going Around 25-30. Rpm’s drop to 1300. Only way to make it go away is give it more gas. Makes it very hard to drive the speed limit in these situations. I can make the ruble go as long as I want if i don’t change throttle pressure. Hard to believe this is normal but guess it is.

Manually shift to fourth.

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