<P> Shortly before the season began, the series was moved from its successful Thursday 8: 00 pm time slot to Monday 8: 00 pm to make way for the impending hit series Mork & Mindy . </P> <P> Virtually the entire writing staff was fired after season 3, and replaced with veteran writers from family - based series (such as Bob Claver from Leave It To Beaver and The Munsters). </P> <P> Travolta, who had already starred in box office hits such as Grease, Saturday Night Fever, and Carrie, began to focus more time on his film career . He was featured in eight episodes, earning $2,000 for each one, and he was billed as a special guest star . </P> <P> Mr. Woodman was promoted to Principal of the school (Principal Lazarus quit to take a "less stressful" job at a high - security prison), and Kotter was promoted to Vice-Principal, purposefully moving the show's focus away from Kotter's class . </P>

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