Two weeks ago I took my 2018 Ford F150 Lariat (72k Miles) into the dealership and following Ford's protocol they capped the IWE Vacuum System. Since then it's snowed quite a bit here and today I started drive my truck up a snowy hill in 4A, and from a dead stop it made a nasty grinding noise. I've driven up this hill countless times in 2H and never noticed any noise. Could it be the hubs? or perhaps a differential issue?

Update: I just noticed I didn't have the snow/wet driving condition on and just had it in normal? Could that effect this?

Help!

 

no if the problem started after the capped it, that's probably the issue. The hubs are probably not engaged fully. I'm not sure how you would get them to fully engage. Maybe find where the cap is and open it, the system may have developed some vacuum with temperature differential from when the capped it and when the system tried to go into 4 wheel drive.