Empty Nest
Now that Lori Beth, Richie, Jr. and now Joanie have left the house, Howard and Marion both struggle to define life together alone, and to find a way to occupy their spare time together, while Fonzie finds that running the restaurant without Al, (who's moved to Chicago with his new wife Louisa, his aunt and Chachi's mom to start their own restaurant there), causes his social life to suffer, which causes him to want to sell his half of Arnold's Drive-In back to old friend, former and original owner Arnold (Pat Morita).
It aired on October 19, 1982.