I have a 2013 Ford F-150 Fx4 package. I have had an issue with the 4x4 for quite awhile. I tried fixing it last year and couldn't figure out how to so I just popped the hood and unplugged the wire harness for the 4x4 and said forget about it, but now I need to try to get it fixed again. I understand this 4x4 system on the ford trucks of this generation is vacuum driven and there are 4 main components to it such as; the vacuum valve, the solenoid, the vacuum lines, and the hub actuators. I have literaly replaced every component and it still isn't fixed. Unless the truck is in 4hi or 4lo, the hub acuators are not suppose to engage. So you would think, but even when it is in 2wd, and your driving down the road, it makes this humming/grinding noise and that is the hubs partially trying to engage in 2wd and i guess it's chewing the teeth up on the hubs. I'm not sure if the acuators i bought brand new were defective or what the case is, but as I said earlier when I unplug the wire harness underneath the hood, the grinding stops. If someone could help me with this issue I would greatly appreciate it. Thank you.
Well, this four-wheel drive systems on those Ford's always work on a crappy. I am not a fan at all. I've gotten brand new ones that had 1500 mi demo vehicles and the damn things home to even then. But if you know any good four-wheel drive guys in your area at least of them road tested with their scan tool. See what they say about it. You're probably fine. It'll cost a small fortune to fix it correctly though
Actually all it turned out to be was the vacum line had a large split in it. So, it wasn't getting enough vacum to disengage the acuators all the way when going back in 2wd. The passenger side was stuck. I appreciate your response. Thanks Scotty!