The new matte black rugged ridge boulder aluminum differential covers are constructed from a356-t6 cast aluminum for strong impact resistance and feature a precision machined sealing surface, allowing gaskets or RTV sealant to be used for a leak-free seal. Each cover is designed to help protect internal components from damage caused by contact with rocks and other terrain off-road as well as aid in dissipating heat from differentials. These covers also come complete with a magnetic drain plug for protection against costly damage from metal particles that can accumulate in gear oil and include a specially designed dipstick bolt to help jeep owners avoid under or overfilling their differentials.