I flushed out my rear axle let it dry good before putting things back together. The oil was black enough kind of had that used smell so i am sure it will be happier. It now has JT7 syn. I used a fle pro gasket to seal it. A few things i noticed. First i didnt have a magnet in the cover to clean. Second there are two holes that are in line with the axle shafts. What do these do? I know i didnt clog them becuase i used a gasket and they are cut out Just wanting to learn more. Happy to say no drips from the rear and took the truck around the block Its a 10 bolt rear also 3.42 open diff