Analysis of Leakage
WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
Clean up the leaking area enough to identify the exact source.
A plugged Rear Drive Unit (RDU) housing vent can cause excessive pinion seal lip wear due to internal pressure buildup.
Verify the RDU lubricant level is at least 3-5 mm (1/8-3/16 in) below the bottom of the fill hole.