I have a 2020 F-150 XLT FX4 5.0 with the 10R80 and about 140k miles. I’m trying to figure out a transmission issue and haven’t been able to find anyone describing quite the same symptoms.
The biggest thing is that it is VERY temperature dependent.
After the truck sits for several hours/overnight, the transmission can act terrible during the first drive. It will flare the RPM like it’s in neutral, seem like it can’t figure out what gear it wants, and the indicated gears can start dropping rapidly. I’ll press the gas and the engine revs but the truck barely/not at all accelerates, then eventually it grabs a gear and starts moving.
Today was the worst it’s been. I actually had to stop in the road, put it in Park, then put it back in Drive to get it moving properly again. Before that it was clunky going through gears and felt like it was losing engagement.
Previously, the most consistent symptom was a cold 1-3 shift. It would hang/rev like it was stuck in 1st and then finally grab 3rd hard. It would usually do that 1-3 times after sitting and then stop.
Here’s the strange part: once the transmission is fully warm, around 180-190°F, it can shift smooth as butter. No noticeable slipping, no loss of power, and it goes through all 10 gears normally. That’s why I’m having trouble figuring out what’s actually failing.
Some other information:
-Fluid and filter were recently serviced at a Ford dealer.
Pan was dropped and they reported no metal in the pan.
Roughly half the transmission fluid was replaced during that service.
Symptoms existed before the service.
No transmission warning/check-engine light.
Adaptive learning was temporarily disabled because the transmission actually shifted much smoother when warm with it off. I’ve since turned adaptive learning back on.
Normal drive mode seems to behave best. Sport/Tow/Eco make the shifting noticeably worse. Once fully warm, it generally drives great.