WABC, the New York station where Grant spent much of his career, announced he died Tuesday in Hililsborough, N.J., the New York Times reported.
Grant was born Robert Ciro Gigante to Italian immigrant parents in Chicago. After a stint as a radio reporter, he was introduced to two-way talk as a substitute for Joe Pyne, who hosted a show in Los Angeles that became nationally syndicated in 1965.
"Bob, you are a man who has paved the way for others to come along and do it," Limbaugh said at a 1991 event honoring Grant. "I am grateful to you."
While Grant supported Republicans over Democrats and took other conservative positions, it was his remarks on race that were most controversial. He said Dinkins, New York's first black mayor, reminded him of the attendant in the men's room at his favorite restaurant and in 1993 leveled a string of epithets at King -- "phony" and "womanizer" among others -- in addition to "slimeball."
WABC fired Grant in 1996 for his comments on the plane crash in Croatia that killed U.S. Commerce Secretary Ron Brown.
"My hunch is that he is the one survivor," Grant said about media reports that one person on the plane had lived. "I just have that hunch. Maybe it's because, at heart, I'm a pessimist."
Grant went to work for WOR, which had been his home before he joined WABC. He remained on the air, returning briefly to WABC and then on an Internet show, retiring in 2012.
He denied being a racist, saying he admired many blacks, including Justice Clarence Thomas and Roy Innis, head of the Congress of Racial Equality.
Grant was also known for his confrontational style with his callers. He hung up on those who disagreed with him but also on those who were too fulsome in their agreement.