That big nut holds the cover on, but it doesn't come out of the cover. Once the nut is loose, the cover will come off, but it will need help. Its just stuck. When you get a new filter, (get the number off the top of the old element), and make sure you get two new gaskets with it. The cover gasket and the bottom of the filter gasket. The top cover has to be sealed perfectly and quite tight or it will leak.
We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.
Niel Hoback's post in 1950 Plymouth Oil Filter Replacement was marked as the answer