Casting Porosity

There may be a rear axle housing leak through small pockets in the metal. These pockets (casting leakage) are caused by gas bubbles in the casting process, known technically as a porous condition or porosity.

Because there is a concern of changing the axle's Noise, Vibration, and Harshness (NVH) characteristics if disassembled to replace the differential case, service is preferable. Seal the porous pocket with Devcon Aluminum Liquid F2 meeting Ford specification M3D35-A(E).