“We’ll always be together. Wha oooh, yeah!”

Grease started off as a musical in 1971. It was created by an advertising copywriter named Jim Jacobs and a high school art teacher named Warren Casey. It was adapted into a film in 1978.

Kingston Mines Theatre Company

The title, Grease, was a way for the creators to pay homage to the 1950s and the era’s “greasy hair, greasy engines, and greasy food.”

Rosemary Matthews / Getty Images

Happy Days star Henry Winkler was originally offered the role of Danny Zuko, but he turned it down out of fear of being typecast.

ABC

John Mitchell / Getty Images

Archive Photos / Getty Images

The song “Beauty School Dropout” got its name after the writers for Grease saw a news report about a teenager who dropped out of beauty school and became a murderer.

Paramount Pictures

For the movie, a lyric from “Look At Me, I’m Sandra Dee” was changed to something a little more sexual: “Elvis, Elvis, let me be! Keep that pelvis far from me!” Coincidentally, Elvis Presley died the same day the scene was filmed, August 16, 1977.

Paramount Pictures

While filming, everyone in the primary cast was actually too old to be in high school. Director Randal Kleiser administered a “crow’s-feet test” around their eyes to make sure they could pass for teens.

• John Travolta (Danny Zuko) was 23.
• Olivia Newton-John (Sandy Olsson) was 29.
• Stockard Channing (Betty Rizzo) was 33.
• Jeff Conaway (Kenickie) was 26.
• Didi Conn (Frenchy) was 25.
• Barry Pearl (Doody) was 27.
• Jamie Donnelly (Jan) was 30.
• Michael Tucci (Sonny LaTierri) was 31.
• Dina Manoff (Marty Maraschino) was 19.
• Kelly Ward (Putzie) was 19.

Paramount Pictures

Lucille Ball’s daughter Lucie Arnaz was originally up for the role of Rizzo, but was later dropped from consideration after her mom told producers this: “I used to own that studio; my daughter’s not doing a screen test!”

It turns out Lucille Ball owned DesiLu Productions, which was bought by Paramount.

Fpg / Getty Images

Instead of using makeup, Jeff Conaway (Kenickie) insisted on really giving Stockard Channing (Rizzo) real hickeys and he did! Remember, “A hickey from Kenickie is like a Hallmark card.”

Paramount Pictures

Dina Manoff (Marty) was not a good dancer at all, so they made sure to exclude her character from all of the dance numbers.

Paramount Pictures

“Greased Lightening” was originally supposed to be Jeff Conaway’s (Kenickie) song like it is in the musical, but John Travolta (Danny) insisted he sing it. This caused a bit of tension on set.

“I have to be completely honest with you,” Travolta said. “I wanted the number. And because I had clout, I could get the number.”

Paramount Pictures

Jeff Conaway (Kenickie) injured his back while filming “Greased Lightning.” Fellow cast members accidentally dropped him while dancing on top of a car. The injury eventually ignited his pain killer addiction, which led to his untimely death in 2011.

Paramount Pictures

The scene where John Travolta (Danny) pulls out Saran wrap during the “Greased Lightning” number is actually a sexual reference to condoms.

Paramount Pictures

The “Sandy” number would’ve ended differently if it were up to John Travolta (Danny). Instead of the hot dog jumping in the bun, Travolta wanted a close-up.

“He wanted a close-up on him,” Randal Kleiser said. “But that hot dog was fantastic. I didn’t want to shoot the close-up because I loved the hot dog. That was a battle, but I won.”

Paramount Pictures

Production was halted during the drag-racing scene, due to cast members becoming mildly ill due to the filthy water in the LA River. Director Randal Kleiser even caught a foot infection because of it.

John Travolta reportedly administered a Scientology “touch assist” on Randal Kleiser’s foot.

“I was lying there with this fever and he’s poking me and poking me and poking me,” Kleiser said. “I’m like, ‘Yes, I feel it.’ ‘Thank you.’ Then he left. The next day I was better, and of course he claimed it was because of the touch assist.”

Paramount Pictures

John Travolta (Danny) was still grieving the loss of his love Diana Hyland, who died from breast cancer in his arms. He called the film director at all hours of the night to talk.

Central Press / Getty Images

Olivia Newton-John was extremely hesitant about making her transition from “good girl” Sandy to “leather and spandex” wearing Sandy. John Travolta (Danny) actually had to talk her into it.

“That was such a stretch, and something I was really worried about,” Newton-John said. “But when it happened, it was just this amazing feeling. It was very freeing. Not just for Sandy, but for me as well. Because I was always the girl next door.”

Paramount Pictures

Speaking of spandex, Olivia Newton-John’s pants were so tight when filming “You’re the One That I Want,” that she had to be ripped out of them and sewn into them.

Paramount Pictures

It actually only took one day to film “You’re the One That I Want” and the end scene. There was also a real traveling circus there.

Paramount Pictures / Via youtube.com

And the iconic dance contest took an entire week to film. It was shot in Huntington Park High School in Los Angeles. Temperatures reached a scorching 116 degrees during filming, which caused several extras to get mildly ill.

Paramount Pictures

Scott Wintrow / Getty Images

Jeff Conaway (Kenickie) had a big crush on Olivia Newton-John (Sandy) and was really nervous around her on set. Oddly enough, he ended up marrying her sister, Rona Newton-John.

Getty Images

In the original stage production of the show, Sandy’s last name was actually Dumbrowski and was of Polish-American decent. They eventually decided to change it for the film to match her Australian background.

Paramount Pictures

“Hopelessly Devoted To You” was written AFTER they finished filming the movie. Olivia Newton-John’s ballad was the only Grease song nominated for a 1979 Oscar. It was up for Best Original Song but lost to Donna Summer’s “Last Dance.”

Paramount Pictures / Via youtube.com

Annette Charles (Cha Cha DiGregorio) suffered an ectopic pregnancy while filming Grease. After filming the drag-racing scene, she was rushed to the hospital for emergency surgery.

Paramount Pictures

Coca-Cola initially had a product-placement deal with the film producers, but after negotiations went south, they were forced to obscure all references to the beverage in post-production.

Topical Press Agency / Getty Images

Believe it or not, the word “grease” is never said in the film, only “greased.”

Paramount Pictures

John Travolta’s sister, Ellen Travolta, plays a diner waitress in the film. She had one line: “Oh, there’s Danny and Sandy,” which was said while watching the dance contest on TV.

She’s the brunette closest to the television.

Paramount Pictures

Rydell High takes place at three different LA high schools. The building’s exterior is Venice High School, the interior is Huntington Park High School, and the field is John Marshall High School.

Paramount Pictures

John Travolta (Danny) kept messing up a line so much, they decided to just keep it in the movie. He says “heap lap trials” instead of “heat lap trials.”

Paramount Pictures

One of the original adaptation ideas was to make Grease an animated movie. It ultimately became a live-action film, so they decided to just make the opening credits animated instead.

Paramount Pictures

Grease became the highest grossing film in 1978. Its soundtrack was the second best-selling album of the year, behind Saturday Night Fever which also starred John Travolta.

Paramount Pictures