Strange transmission issue.

[Frank_N]

I have a 2021 F150 with a 3.5L engine which has strange transmission problems. The truck is parked in the driveway with a slight incline, front higher than rear. When I back up I am going downhill and the truck will easily roll downhill in if I put it in neutral. Parking brake and hill assist are off.

1. In the morning I start the truck and put it into reverse. I am moving back slowly and applying the brakes lightly as I am reversing watching for traffic.

2. The truck will go back a little bit and stop reversing by itself like it is being blocked by snow or something else but it is not. It appears to lock up in reverse like something is binding. I can remove my foot from the brake but the truck does not move.

3. In order to continue to reverse I have to switch from R to N and back to R (sometimes I need to do this typically once and up to five times to get the truck moving). The truck does roll back when in neutral since I am on a slight incline when I do this. I can also rev the engine higher to about 2000 RPM and it seems to slam into gear to get it to move (concerning and unsafe).

4. The problem is repeatable and happens almost daily when it is below or close to freezing.

The truck has been to the dealer twice. The first time the tested the CDF drum and checked the fluid level. The second time Ford told them to replace the valve body in the transmission. Neither of these have helped and the truck is going in again for this problem.

Has anyone ever had this problem or any idea of what is happening?

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[Davexxxx]

Is your rear camera, or any of the rear sensors out of alignment?

It almost sounds like the accident avoidance system is being overly sensitive.

 

[Bunker]

Mine does the exact thing, but only below 20*F. Does it still do it if you wait a few minutes for the fluid to warm up? That seems to solve mine. I have several weeks to wait to see the dealer about mine and since it’s only reproducible below 20*F, I’m sure they’ll tell me to have a nice day.

 

[Davexxxx]

I remember why these symptoms sound so familiar.

Do you by chance leave a hitch in your receiver?

I was on some forest service trails and needed to turn around. Found a safe place but it had a decent incline and maybe waist high weeds all around. My truck did not want to back into that, exhibiting similar symptoms as you. Minus the bars obviously but my WDH was in the receiver at the time and my system confuses the adjustment portion for the ball.

It has never happened again but its never been in those exact conditions again either.

 

[Frank_N]

I remember why these symptoms sound so familiar.

Do you by chance leave a hitch in your receiver?

I was on some forest service trails and needed to turn around. Found a safe place but it had a decent incline and maybe waist high weeds all around. My truck did not want to back into that, exhibiting similar symptoms as you. Minus the bars obviously but my WDH was in the receiver at the time and my system confuses the adjustment portion for the ball.

It has never happened again but its never been in those exact conditions again either.

There is nothing in the hitch receiver and no audible warnings or warning lights when this happens. The dealer has also been able to replicate this problem. If I step on the gas hard enough it seems to slam into gear. Seems to me that it is not fully engaging in reverse.

 

[Davexxxx]

There is nothing in the hitch receiver and no audible warnings or warning lights when this happens. The dealer has also been able to replicate this problem. If I step on the gas hard enough it seems to slam into gear. Seems to me that it is not fully engaging in reverse.

OK. Good luck and please check back with what they find.

 

[v8440]

I had something similar happen with my new '24. I think it was the brake being applied because of an oversensitive safety system. It was very cold when mine did it too, and a slight downward incline behind the truck. I disabled that dumbness in the options somewhere.

 

[HammaMan]

The trucks apply the ebrake on certain inclines. You can check if it's the ebrake by pushing it in (left knee). I think it's an anti-roll nanny feature. Pushing the gas also unlocks the ebrake.

 

[v8440]

Yep, I recall the truck lurched rearward with a real jerk when I pressed the gas lightly. Overall it seems like a very spastic "feature" that fortunately can be disabled in the settings.

 

[HammaMan]

Yep, I recall the truck lurched rearward with a real jerk when I pressed the gas lightly. Overall it seems like a very spastic "feature" that fortunately can be disabled in the settings.

Oh, there's a couple nannies on the truck. You have auto-hold which is not the ebrake incline thing. They're 2 different things. Auto hold (great feature) will hold the brakes after the truck comes to a stop AND you've put enough force into the pedal to hold it. A real soft drag stop might not full engage the auto hold.

I don't know the conditions for auto-ebrake but it does it on inclines including when going to park. Auto hold uses the brakes, the auto-ebrake is a different thing entirely using the ebrake which is slower engage/disengage (also illuminates the ebrake light).

 

[Frank_N]

Yep, I recall the truck lurched rearward with a real jerk when I pressed the gas lightly. Overall it seems like a very spastic "feature" that fortunately can be disabled in the settings.

It is in at the dealers today for the 3rd time. Auto hold is disabled and the parking brake is not on when this happens. Ford corporate has also been giving advice to the dealer on this so I suspect they would know if anything needed to be disabled in the settings.

 

[Bunker]

There is nothing in the hitch receiver and no audible warnings or warning lights when this happens. The dealer has also been able to replicate this problem. If I step on the gas hard enough it seems to slam into gear. Seems to me that it is not fully engaging in reverse.

Very interested to hear what the problem and solution may be.

Mine is the same. Nothing in the hitch, no bells or warnings or messages. One time after backing I put it into drive and it seemed to slam into gear after using a slight amount of gas to get it to move forward. Since then I just let it warm up before moving and it only seemed to happen when cold outside.

 

[Davexxxx]

Maybe related, maybe not but I didn't care for the, take off performance, of auto hold.

Seemed unnecessarily jerky and I turned it off and never looked back.

 

[Bunker]

Maybe related, maybe not but I didn't care for the, take off performance, of auto hold.

Seemed unnecessarily jerky and I turned it off and never looked back.

I’ve got the auto hold of for a few reasons. It complicates trailer hookup. Sometimes you just need to move an inch, but don’t want to use two pedals to do it “safely“. I also don’t like how it engages with every stop. Our other cars only engage hold if you stab or press the brake with some force give you the option to use it at will. And lastly I have a situation with auto hold where sometimes when I stop the truck with lurch forward just slightly almost like I was bumped from behind. Dealer couldn’t recreate it so they said it’s normal.

But yes, great advice and I agree.

 

[Mud]

Is your rear camera, or any of the rear sensors out of alignment?

It almost sounds like the accident avoidance system is being overly sensitive.

My truck does similar! Its trying to save your life. Enjoy

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