aFe Power Cover Diff Rear Machined COV Diff R Ford Diesel Trucks 86-11 V8-6.4/6.7L (td) MachinedThis cover has an increased oil capacity over stock for better performance over a longer duration. Built in internal and external fins transfer heat from the oil to the outside air for maximum cooling. This cover incorporates a magnetic drain and deep reach fill plug to capture loose particles for maximum protection. A calibration plug is set to the factory oil level to prevent overfilling. A pre installed oil level sight glass allows quick and easy