I'm in need of some assistance. I've got a 2012 F150 4x4 Platinum with the ecoboost motor. I recently got into a non-contact accident and slid into a curb while trying to avoid a driver that pulled out in front of me.
The front left wheel is what hit the curb. The initial repair to the truck was refinishing of the wheel, replacing the lower control arm, and straightening the tabs on the frame where the lower control arms mounts. After that repair there was a cyclic noise coming from the front end and it was determined to the the left front unit bearing. That was replaced. Now, after the truck has been driven for a while, a vibration (and almost a slight tapping)can be felt in the steering wheel and gas pedal and there's a low pitch "vibration noise" associated with it. The repair shop thought it may have been the CV axle. That was replaced and it didn't make a bit of difference. The kicker is that the noise and vibration goes away when the truck is switched to four wheel auto. I have not put the truck in 4 wheel drive to see if goes away in that setting.
Can anyone offer any suggestions on what could be the culprit for this vibration and noise?

 

I wouldn't have the slightest clue as to what is causing the issue, but have you tried rotating the front left wheel to the rear? Maybe the tire needs to be replaced or rebalanced.

 

I would swap wheels as suggested by toolman00. You might also check the vacuum lines to the IWE (Independent Wheel End)on the driver side. If the line was stretched or torn in the accident it will also cause grief. The loss of vacuum to the system engages the IWE for 4x4 use. Partial vacuum loss will not fully engage the IWE causing the noise. When you engage 4x4 it removes vacuum and the IWE positively engages eliminating the noise.