Dealership said it is normal but it doesn’t seem normal… ‘21 5.0 F150
I had a 10r80 rebuild under warranty at 96k miles (CDF drum failure requiring a complete overhaul) because of rough shifts and a brief grind when applying throttle. I drove it 300 miles and the grind returned along with the occasional rough shifts. Dealership took the truck back under Ford’s recommendation and replaced the entire throttle body assembly. The dealership test drove it after the work and found the grind was still there. Ford later told them it is normal operation for a 2021 F-150 coyote engine and recommended no further work.
The video is the replication of the symptom. Applying throttle after a coast down results in a grind that is louder in the cab than on video. It’s pretty consistent.
At this point I am 2 months past warranty and every time I hear the grind, my stomach drops. Since Ford said it’s “normal”, no Ford dealership will touch it. It occurs constantly in stop and go traffic or any condition where I briefly coast to ~1000 RPMS then tap the throttle. (See comments for dealership tech writeup on how they replicated it). I’ve read an explanation that it’s from the oil pressure.
My question is: Can someone confirm this is “normal”? I thought after getting the updated CDF drum I would be in the clear, but I can’t seem to find enough information on this issue to find peace about it. If anyone is willing to try to replicate this on their ‘21-23 5.0, I would appreciate it. I drive a lot for work and just want to know if I should be planning an upgrade in the near future.
TLDR: I have a persistent grind accelerating out of a coast down in my ‘21 coyote F150 after overhaul. Ford said it’s normal. Does anyone have a similar experience or explanation? TIA.