NHTSA Complaint #11610401 — 2023 FORD F-150

In cold temperatures the vacuum system that keeps 4x4 disengaged seems to be failing. There is a loud grinding noise with vibrations when driving any speed. It will go away after you engage 4 wheel drive. I feel this is unsafe and worry with winter coming soon the hubs may lock up causing a head on collision or cause vehicle to go in the ditch. I’ve had this issue since I first bought the pickup brand new in late October of 2023. In above freezing temperatures the grinding and vibration does not happen. No light warning indications when this will happen either. I have called the dealer and made a case number, they say engineering is looking into it. They tried replacing the IWEs and it didn’t make a difference. I’ve done a lot of research online and many people all over in colder climates are experiencing the same thing.