I went to a Mag-Hytec on our Ram 3500. An aluminum cover with additional fluid capacity, having raised ribs on he case outside for greater surface area for additional cooling. It has a magnetic drain plug, a sight glass for easy level observation, and is drilled/tapped for a temperature probe (should you desire one)! They’ve been around many years! I’m not sure what fluids Ford used in ‘03, but with my Ram, I went to a higher weight rating ( I tow quite heavy loads) full synthetic oil...... Mobile 1 differential lube! Any good differential oil should be fine......nothing wrong with using the oil that Ford spec’d the vehicle with! memtb
