S05E30: The Merchant Marine

Angry with his dad for taking his car keys away, Lumpy Rutherford decides to secretly join the Merchant Marine Corp and has the enlistment information sent to the Cleaver's address instead of his own. Trying to be a good friend, Wally hides the Corp literature in his room; but, when June finds it while cleaning, she's sure that a break-up with his girlfriend and a recent reprimand from Ward have made Wally unhappy enough to leave home.