The contact owns a 2016 Ford F-150. The contact stated while driving approximately 30 MPH uphill on several occasions, the vehicle made an abnormal grinding sound. There was no warning light illuminated. The vehicle was taken to the dealer; however, the failure could not be duplicated. The contact stated that the failure was intermittent. The vehicle was taken to Lonstein’s Motors Inc, where the gears were taken apart, and the mechanic diagnosed that the integrated wheel end (IWE) of the 4WD system was partially engaging unintendedly, causing gears to grind against each other and to become damaged. The mechanic noticed the presence of metal shavings. The mechanic replaced the left and right hub assemblies, two actuators, the vacuum lines, and the tubing solenoid. The vehicle was repaired. The contact related the failure to TSB Number: 18-2273. The manufacturer was notified of the failure and informed the contact that the vehicle was not covered under warranty. The failure mileage was approximately 49,000.