F150 2014 Iwe4x4 grinding and rubbing sound in 2wd and In 4wd

I have a 2014 stx 4x4 that keeps having grinding and rubbing sounds coming from the front end. Sometimes it comes when just driving in 2wd the other times when shifting into 4wd. I took it to the dealership 3 times so far. The first time they said they replaced all 3 IWE'S. The sound went away for a week. So I took it back the second time they replaced the front axle and the solenoid for the IWE. They had it for a week this time I picked it up friday and its still making the whinning and grinding sound like its partially engaged. The truck was sold to me certified pre-owned and only has 19,000 mi. Has anyone else had these same problems?