2021 F150 Crew Lariat 3.5, has a vibration at 63-65 MPH. I brought it in for service several months ago, and the dealer said the trans was down 2 quarts. After that it felt fine, but I can hear and feel the vibration again. Has anyone else experienced this before?

 

Down Two Quarts is worrisome. Did they say where the two quarts went? A half gallon is a lot of "leakage", especially trans fluid. That stuff gets everywhere. Did you see puddles? I'm guessing the vibration is not the issue, but the leak is. Vibration ... add two quarts ... vibration gone ... vibration comes back. Guessing you are down again.

 

No leaks at all. Still covered under Extended Warranty though. I have about 50K on it and hardly ever tow anything. However, I am the second owner.

 

The fluid has to be going somewhere ... unless there was a prior leak and the PO didn't refill after repairing the leak. The fact that after filling the vibration came back, I would keep an eye on the fluid level.

 

At 50,000, miles is the truck ready for the fluid to be drained completely (13 quarts), or just a pan drop (6-7 quarts)? I don’t know why they didn’t offer this when I brought it in. It does have an extended warranty to 75,000 miles.