Welp, still dealing with this issue. Monday will mark 5 weeks at the dealership. To recap, they initially said it was something to do with the IWE system (they did not specify and I didn't ask, my service adviser isn't the best at being specific about what's going on). After fixing whatever they thought was the issue the adviser communicated that now it pulls to the opposite side. I am not sure if this is truly the case or if he just misremembered which side it was pulling to to begin with. At this point I informed them that I had recently purchased and installed new (KO2) tires, in the event that one may be defective. The adviser said he would pass that on to the techs. After further investigation they decided it was the front differential, which required a full tear down to investigate.
That brings us to the last few weeks. After taking apart the diff they told me they found metal in it so they replaced various pieces/parts. Again, the adviser was not specific about what was done here. They then put it all back together and claimed that a 'sound' was still present in the front diff, which needed further investigation. They couldn't find anything so they contacted 'Ford Engineering' to provide input about what to do next. We seemed to be going down a rabbit hole here, at which point I inquired about whether the initial problem I brought it in for (pulling to the left in 4A/4H) was fixed. The adviser told me that it was better (lol), but still pulled to the side.
After some time Ford advised them to rotate the tires, check the alignment, and check the ride height. They did this and found nothing wrong and have said they've provided all the documentation/info back to Ford for further instruction about what to do. I pressed them on the new tires and whether they've tried moving them around, to which the adviser said the techs have done this without anything changing.
They have no idea what is causing this or how to fix it (my inference based on the circumstances, they haven't used those exact words verbatim). I'm also not clear about whether we're still dealing with the initial problem (I think so) or a 'noise'. They've given me a loaner, which I am thankful for. The adviser, besides never getting back to me with an update when he says he will and being vague in those updates when I eventually call, has been nice to deal with. I get the sense they are frustrated and want this thing gone. Of course I am frustrated and want it back, but only if it's fixed. Ugh.
I'm probably thinking way down the line here, but what happens if they can't fix it? And/or how long can this go on for (holding my truck and not fixing it)?