Frank Bank, who played Wally’s friend Lumpy Rutherford, recalled taking a quart of melted ice cream (which, he confessed in an interview, was actually yogurt) over the head in “Wally’s Weekend Job” (Season 5, Episode 6). Ken Osmond  the slick, weaselly Eddie Haskell, one of the most memorable characters television has ever seen  spoke of receiving a faceful of differential fluid in “Wally’s Practical Joke” (Season 6, Episode 35). Jerry Mathers, the Beaver, still cringes at “Beaver, the Bunny” (Season 5, Episode 16), in which he ended up in a ridiculous rabbit suit for a school pageant. (The episode gave Lumpy the opportunity to utter the memorable line: “Beaver in a bunny suit. The only thing that would be funnier would be a bunny in a beaver suit.”) And Mr. Dow cited “Wally, the Lifeguard” (Season 4, Episode 4), in which Wally thinks he has been hired as a lifeguard but finds himself hawking hot dogs instead. “They put a goofy-looking hat on me,” Mr. Dow recalled. Yes, Wally is still saying “goofy.”

Image A still from Season 5. Credit... SHOUT! FACTORY/NBC Universal

It seems like a perfect instance of brotherly rivalry that, when asked to choose his favorite episode, Mr. Mathers picked the show that Mr. Dow named as his most humiliating. But that’s an illusion; Mr. Mathers said his selection was based on the memory of the down time between scenes, when he outfished Mr. Dow in what is now called Jaws Lake on Universal’s back lot.

Mr. Dow named as his favorite “Happy Weekend” (Season 2, Episode 13), a wise, wistful tale in which the boys’ father, Ward (Hugh Beaumont), drags them against their will to the cabin where he used to vacation as a child. Like so many of the series’s best installments, that one was written by the show’s creators, Joe Connelly and Bob Mosher, men apparently obsessed with bathing. The subject comes up seemingly in every episode, including “Happy Weekend.” “Hot dog, Beaver!” Wally says as the boys are looking over the cabin. “There’s no bathtub!”

Maybe the cleanliness fixation was a manifestation of the way Mr. Connelly and Mr. Mosher ran their operation: protectively, Mr. Dow said, with an eye out for the negative influences that have derailed so many child stars since. “There were drugs and alcohol when we grew up, but we had this tremendous core of support, first from our families, but also from the writers and others who worked on the show,” Mr. Dow said. “I remember there was this crewman who said ‘dammit’ or something once. Never saw him again.”

Image The whole family, from left, Hugh Beaumont, Mr. Dow, Barbara Billingsley and Mr. Mathers. Credit... SHOUT! FACTORY/NBC Universal

Mr. Dow went on to have success as a television director (“Coach,” “Babylon 5”). Mr. Mathers  despite having been killed in Vietnam, according to a false rumor that floated around for years  graduated from Berkeley and for a time went into banking, though he continued to act (including in “Hairspray” on Broadway, a job he’s particularly proud of). Mr. Bank became a financial consultant, and Mr. Osmond was for years a Los Angeles police officer. (In one of the discs’ bonus features, he gives a matter-of-fact account of the time he was shot in the line of duty.)