Rear Differential Cover for RAM/GM 2500/3500 HD Made from high-quality cast A356.0-T6 aluminum for strength and optimum heat dissipation. PPE’s differential covers (Rear Differential Cover RAM/GM) offer industry-leading fluid cooling. Equipped with internal heat sinks and external cooling fins, increasing the pan’s surface area helps dissipate heat. This makes for a much cooler and denser oil. The cool, dense fluid lubricates better, which will extend differential service life. To keep the fluid clean, PPE installed its exclusive high-powered Neodymium magnet-equipped fill plug that pulls harmful ferrous metal particles right out of the oil before they can attack the bearings and gears. OEM Part Number for Reference: GM 22891940, MOPAR 5086904AD Note: This part is not compatible with certain 06-12 Dodge Ram HD trucks equipped with Anti-Spin Differential Rear Axle due to the Tone Ring Sensor. For these trucks, refer to Part Number 138051000.