Some 2013-2018 F-150/Expedition/Navigator vehicles equipped with four wheel drive (4WD) may exhibit an intermittent grinding noise while driving in two wheel drive (2WD) mode most commonly on acceleration. This may be due to a loss of vacuum to the integrated wheel end (IWE) actuators and/or wear of the IWE components. To correct the condition, follow the Service Procedure steps to replace the worn vacuum and/or IWE components.
