The crank seal has been replaced but it still leaks
Try a crankshaft repair sleeve. When a groove is worn in the
crankshaft seal area, a new seal will not have a smooth surface to
seal against. It will either leak immediately or wear prematurely.
Replacing the crankshaft will solve the problem, but it is an
expensive fix. An economical and effective alternative is installing
a slip-on repair sleeve.