Greetings.
I have a 17 350 dually. 4:10s.
Use it as a truck, hauling stuff. A few time a year it pulls a 42 ft ~16k fifth wheel.

No matter the load when cruising down the highway in 5th or 6th I could roll on the throtte about halfway, it would spool up and the wonderful turbo torque would speed me down the road.
Lately I have noticed that often it will downshift taking the rpms to a higher than normal range and I would lose the low end pull.
Does this have anything to do with the transmission solenoids starting to stick?
Otherwise it shifts normally, no issues when pulling the trailer.
50k miles, well taken care of
Fluid and filter changed at 20k, motorcraft ft187 Motrorcraft LV fluid.

Thanks for any thoughts.

 

If the solenoids were sticking it wouldn't shift when it was supposed to shift.

 

How many miles on this truck?
when was it last serviced? filters oils etc.
Do you run any fuel additives and or injector cleaners?
Also what are your driving habits these trucks do not like to idle a lot and need warmed up and run good and hard once and a while.

 

Try changing The Fuel and Air Filters ..
That should help ..

 

If this helps, I had my 2017 F350 DRW repaired and covered under the powertrain warranty (42,300miles). Including transfer case parts (seal, nut-hex, retainer, bolt x 2).
Transmission slipped from 3rd into 4th. I crawled underneath and I noticed transfer case seal leaked transmission, covering bottom of cab rack. I replaced 2 quarts of fluid and made an appointment ASAP. I typed out the issues and handed the document to the service manager. Luckily, I had a gentleman who called me for updates for a week.
He explained the mechanic performed adaptive learning, cleared TCM adaptive learning transmission fluid temp at 195 deg.
This procedure helps the transmission relearn procedure after transmission tuning to help the transmission perform correctly.
Service manager stated because the truck lost of 2 quarts of fluid, the transmission relearns shifting and driving habits. All trucks will experience hesitation during shifts, hard shifts, or defuel patterns, all of which are normal. So, check your transmission level and in the transfer case. Make note what problems you're having at speed and temperature. Make an appointment ASAP. We have several Ford dealership in the area. Visited several Service Managers (dealerships) and knew which one I trusted my truck with. Pending your miles and warranty, I was covered under Powertrain warranty. Hope this helps. Good luck. Truck shifts a lot better and no more slips.

 

Great to know. Thank you. I will get an appointment asap. Thanks!!!!

 

Do you use FORScan? The adaptive learning tables can be reset with FORScan. Although, if you have the time and are under warranty, it might be good to have the dealer put eyes on it. At least have it on record.

 

Thanks. I have used forscan for other items, will have to look into is for this. Not sure, do you know the warranty coverage on transmission issues?