Source---- 6.0 PowerStroke bulletins

Oil Filter Lid Leaks:
To prevent leaks from the oil filter cover, be sure to replace the sealing o-ring when performing oil changes. Torque the cover to 18 ft/lbs. If leaks continue to occur, check the housing for burrs and the lid for damage. If using an aftermarket filter, try a factory one. Broadcast Message 3403.