Harsh downshift after rebuild

[ExpeditonSpec]

I’m curious if others have experienced this with their Ford 10R80 transmission. I have a 2021 Expedition, and every time I’m cruising around 50 mph in 10th gear and crest a hill with light throttle, the transmission harshly downshifts to 8th. I’ve already had the latest TSB/software update, and even after a rebuild, it’s actually getting worse. Has anyone else had this exact issue? How did you handle it with Ford—did they escalate, repair, or replace anything? Any advice or experiences would be really appreciated.

 

[Nimtz31]

Ford should have provided a 2 year warranty with that transmission rebuild. I would start there.

 

[Hellwig]

I’m curious if others have experienced this with their Ford 10R80 transmission. I have a 2021 Expedition, and every time I’m cruising around 50 mph in 10th gear and crest a hill with light throttle, the transmission harshly downshifts to 8th. I’ve already had the latest TSB/software update, and even after a rebuild, it’s actually getting worse. Has anyone else had this exact issue? How did you handle it with Ford—did they escalate, repair, or replace anything? Any advice or experiences would be really appreciated.

10R80's valve body is a mystery. I would suggest going back to dealership and get that checked.

 

[BMW2FORD]

The dealer rebuilt my trans when the CDF drum bushing failed. It started to not upshift when accelerating into 5th for the first few miles of driving about 10k after the rebuild. It shifts smooth from 10th down and always did even before the failure. The quality control and parts in these transmissions really seem to be pure junk! I’ve taken it back to the dealer several times and they state they can’t duplicate it so I’m waiting to drive with the Service Manager or Foreman.

 

[texsn95]

 

[ROBERT BONNER]

View attachment 85555

I worked for Ford in Manufacturing Operations from 1984-2007. That was how we ran the company until "Ford 2000" in the fall of 1994. That's when Ford N.A. started replacing decent hard working American's in middle and upper management with European Morons who never thought Quality was Job 1 and thought that we were over shooting it. By 2000 all was lost. I gave up trying in 2007 and took a voluntary. I still drive all Fords almost more out of morbid curiosity than anything else.

 

[ROBERT BONNER]

I’m curious if others have experienced this with their Ford 10R80 transmission. I have a 2021 Expedition, and every time I’m cruising around 50 mph in 10th gear and crest a hill with light throttle, the transmission harshly downshifts to 8th. I’ve already had the latest TSB/software update, and even after a rebuild, it’s actually getting worse. Has anyone else had this exact issue? How did you handle it with Ford—did they escalate, repair, or replace anything? Any advice or experiences would be really appreciated.

Prior to the rebuild on my 2020 Expedition 10 speed, I experienced the exact same problem that you describe, since the vehicle was new. I noticed that it happened most often when I was in freeway traffic in construction zones. I found that if I stood on it (WOT) to downshift several gears, it wouldn't experience a hard shift event. It was the part throttle downshifts that would make it slam, 10 to 9, 10 to 8, 10 to 7. Sometimes it would do it a couple of times on the same trip. Sometimes I could drive 6,000 miles without a single hard downshift.

I had it rebuilt under warranty in January, 2025. They replaced the CDF Drum, the Valve body and all of the clutch packs along with another couple of pages of parts and reflashed it. I have about 5K on it since the rebuild, so far, no hard shifts. The shift programming is significantly different now, it's more like my '22 F150. It typically goes through every gear on the way up. Before the rebuild it would frequently skip through the gears on upshifts. I spoke with the the bench rebuilder at the dealership (they have 3 dedicated 10 speed rebuilders at the dealer). He said that the valve body was scuffed up, the CDF drum was brinelled.

 

[bocabimmer]

Watch carefully to see if it’s actually going from 10 to 7, and then quickly up to 8. For me it’s that 7-8 shift that’s jerky. Happened before my CDF rebuild, went away after the rebuild then came back, then went away after my second rebuild. Now it’s coming back again.