SOME 2017 F-150 AND TRANSIT VEHICLES BUILT ON OR BEFORE 15-OCT 2016 AND EQUIPPED WITH A 9.75 AXLE MAY EXHIBIT A DIFFERENTIAL HOUSING COVER LEAK. BEFORE APPLYING THE BEAD OF NEW SILICONE SEALANT ALL SURFACES ARE TO BE WIPED THOROUGHLY WITH MOTORCRAFTÙ METAL SURFACE PREP / ZC-31-B WIPES AND ALLOWED TO DRY FOR A MINIMUM OF TWO MINUTES. REFER TO WORKSHOP MANUAL (WSM), SECTION 205-02. RAPTOR VEHICLES MAY ALSO HAVE A DIFFERENTIAL HOUSING COVER STIFFENING RING, THIS MUST BE REINSTALLED DURING THE REPAIR PROCEDURE.