Former Teamsters President Roy L. Williams says he reluctantly helped mob bosses obtain a $60-million loan from a union pension fund on the advice of Jimmy Hoffa after his family was threatened. Williams said two men working for Nick Civella, the late Kansas City, Mo., crime boss, blindfolded him in 1974 and took him to a building and threatened to kill his wife and children if he did not use his influence to obtain the loan for Civella. Williams’ remarks were published in the Warrensburg Star-Journal, which interviewed him last month at his farm south of Warrensburg, Mo. Williams, 73 and in poor health, was released from a federal prison in Springfield, Mo., in September, 1988, after serving three years of a 10-year sentence for attempting to bribe then-Sen. Howard Cannon of Nevada in 1979. Williams was a protege of Hoffa, who was Teamsters president from 1958 to 1971.