The Federal Aviation Administration said the crew reported a vibration.
Pilots declared an emergency so the flight could be be routed quickly back to the airport, and the plane landed and taxied to a gate under its own power, according to the airline.
There were 176 passengers, two pilots and five flight attendants on board the flight, which was scheduled to fly to Los Angeles. Delta said it put passengers on another plane to California.
Delta said the plane was removed from service for evaluation and it was cooperating with investigators and supporting efforts to find the slide.
“As nothing is more important than the safety of our customers and people, Delta flight crews enacted their extensive training and followed procedures to return to JFK,” the airline said in a statement.