2021 Powerboost erratic shifting when highway towing

[Jondj]

I recently had my auxiliary transmission pump changed after getting errors when towing my travel trailer. Now after the replacement the truck will start shifting very erratically when driving highway speeds 60 -75. It goes from 1200 to 3500 rpm and back again sometimes in less then a few seconds lurching as it shifts gears. I brought it in to another dealer as we are snowbirds moving around a bit and told them the aux pump had been changed just before this happened and they updated the transmission solenoid OD strategy which didn’t help at all. I brought it back to the same dealership and they said they couldn’t replicate the problem of course because they can’t tow. I am wondering if anyone else has experienced this problem and what the solution was for it.

I am very worried I will do damage to the transmission if I keep driving it this way and in another month or so I have a 2000 mile trip back home.

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[EricR]

Yikes, I can see why you are worried about your upcoming trip.

Can you take both your truck and trailer to the dealer for a ride-along with a technician?

 

[Jondj]

It’s an option but not a good one as I have my trailer all setup and it seems to take a little while before it happens almost like it has to warm up first. After I posted this I did see a similar one from last year but no resolution to the problem. Before this I never had any transmission shifting problems and thought I had dodged the bullet after reading about lots of people’s issues until this started.

 

[HammaMan]

You're towing at only 1200 RPM? Do you monitor your trans temp?

 

[Nighsight]

Setup a camera and record the event. That will serve as proof of the issue. Take it back and if they still can't identify or replicate the problem, see if they have a data logger that can be installed to capture all of the data. Hopefully they can get it sorted. It's tough with these kind of problems. Finding a good technician that wants to solve it is key

 

[Jondj]

Sorry Typo around 1800 RPM depending on highway speed of course. The temps are all good. I have tried normal and tow/trailer mode. It jumps by 1500 RPM or more easy and really jerks the truck. Very disconcerting.

 

[Jondj]

I will try the camera on our next trip later this week. I understand that since it only happens when towing its hard to diagnose and there are no error codes. I just went on a six hour trip with just the truck and it ran fine no problems at all.

 

[Jondj]

Okay my worst fears have happened. We started heading back home and only made it about an hour or so into the trip and the shifting problem started up. Then going up a slight grade at about 65 the transmission temp relined at 133C. I immediately pulled over and the temp went back down. I checked underneath for any leaks and all looked okay. I took it to the nearest dealership in Mesa and they checked it over and determined that it was the coolant control valve which they replaced after a week in the dearship.
Hooked up the trailer and started our trip back home only to find out that a after a few hours every time we started even a slow climb the transmission temp would start to climb back up. I continued driving but kept my speeds way down. After a days driving during a gas stop I noticed transmission fluid leaking under the truck. Now we are again stuck in a RV park waiting for yet another dealership to take a look at the transmission. I think its time for a new transmission!

I don’t trust that these things can be fixed once they have these types of problems.

 

[Porpoise Hork]

When you had the aux pump replaced do you know if the dealer reset the transmission adaptive tables? If they or no other dealer has then this could be the issue. Part of the adaptive tables is how the transmission learns the correct pressures needed to prevent slippage at various speeds, selected gear, drive mode, etc etc. When the faulty pump was replaced this would alter the internal pressures in the transmission and can cause all sorts of problems from erratic shifts, slippage, to near total loss of power at freeway speeds.

If you have Forscan you can reset the adaptive tables yourself in about 30 seconds. Once reset put in sport or tow mode and calmly drive it around for 20-30 min on surface streets avoiding hard accelerations. Then take it up on the freeway up to 60-70 mph. it will take about 250 miles to relearn everything and shifting should be smoother and when towing provided there's nothing else wrong in the transmission you should notice much better behavior when using tow mode.

 

[Jondj]

Not sure after my transmission hard shifting report (secondr trip to dealer) the dealership referred to TSB-23-2351 and updated the OD transmission solenoid strategy. He told me that after thst update it could take several hundred miles to “relearn the shift points” as he described them. I have driven about a thousand miles mainly without the trailer and no problem but with the trailer something is definitely screwed up. That doesn't sound like quite the same thing you are talking about. Wouldn't that be in the replacement instructions every time they replace that aux pump?

I don't have a forscan here in Idaho Falls and don’t dare drive it now at least towing with the transmission leaking as there is no way to easily get in and check the fluid level of the transmission from what I can tell.

Hopefully I can get someone to look at this tomorrow or help me as we need to get back home. Its been 6 months dealing with this and over two weeks broken down on the road now!

 

[Jondj]

Update the Ford dealership got back to me and after reviewing the history of the transmission problems and talking to Ford they are going to replace the complete transmission. In addition they found the Wheel End hub bolt had broken and now need to replace the rear axle too. Not sure how I feel about this as I am beginning to think this truck is a lemon and should sell it as soon as I get it back. I had to rent a vehicle to get back home while waiting for these parts and the repair which could take a couple of weeks.

I rented a vehicle from Enterprise as directed by the delalership and they gave me a Hyundai Tuscon as we didnt have lots of choices in this small town and now after the fact I was told by the dealer that Ford wont cover the rental unless its a Ford vehicle? Has anyone else run into that? I can't return or trade the vehicle since I am back in Canada until I drive back across the border to go pick up my truck?

 

[HammaMan]

Update the Ford dealership got back to me and after reviewing the history of the transmission problems and talking to Ford they are going to replace the complete transmission. In addition they found the Wheel End hub bolt had broken and now need to replace the rear axle too. Not sure how I feel about this as I am beginning to think this truck is a lemon and should sell it as soon as I get it back.

Sounds like you have a max tow which is subject to recall for this exact issue. As for the trans, you get a brand new one. Why on earth would you get rid of a vehicle that's going to give you plenty of life ahead?

 

[UGADawg96]

Update the Ford dealership got back to me and after reviewing the history of the transmission problems and talking to Ford they are going to replace the complete transmission. In addition they found the Wheel End hub bolt had broken and now need to replace the rear axle too. Not sure how I feel about this as I am beginning to think this truck is a lemon and should sell it as soon as I get it back. I had to rent a vehicle to get back home while waiting for these parts and the repair which could take a couple of weeks.

Sounds like you have a max tow which is subject to recall for this exact issue. As for the trans, you get a brand new one. Why on earth would you get rid of a vehicle that's going to give you plenty of life ahead?

I agree with @HammaMan on this 100%. You have two different issues. Don't worry about the max tow bolt, it is as common as rain. As far as the tranny, sounds like they will be replacing the whole thing. Yes it is frustrating and taking longer than you want, but just be patient, you'll be okay soon and there is no guarantee another vehicle won't have issues too.

 

[Snakebitten]

A lemon is a faulty transmission that after multiple attempts to get it addressed, it still isn't working properly.
Most guys with a transmission-lemon would be thrilled to drop the lemon label if Ford would just swap the 10r80 for another, after failing to fix it successfully.

And I second the motion on the axle bolt.
That's a 30 minute part swap. Literally about the same inconvenience as having an oil change if the part is available and the dealership is competent.

 

[Mosey]

I am curious what gears your trucks shifts from and to. A 1500 rpm jump sounds like at least two gears. Glad to hear you are getting a new tranny.

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