Jim Clack, an offensive lineman who played 11 seasons in the National Football League and won two Super Bowl rings with the Pittsburgh Steelers, died Friday in Greensboro, N.C. He was 58 and lived in Greensboro.

His wife, Susan, said the cause of death was atrial fibrillation. She said he had fought neck and throat cancer for four years.

Clack played guard and center for the Steelers for seven seasons (1971-77) and was part of their 1975 and 1976 championship teams. He was traded to the Giants before the 1978 season and played with them from 1978-1981, becoming their offensive captain.

He retired the day the Giants' training camp opened in 1981 and, the next day, underwent arthroscopic surgery on both knees. But when his replacement, Ernie Hughes, tore a knee ligament at midseason, Ray Perkins, the Giants' coach, called Clack out of retirement. He went on to help them make the playoffs.

James Thomas Clack was born Oct. 26, 1947, in Rocky Mount, N.C., and lettered in football, basketball and track at Wake Forest University. In recent years, he developed commercial and residential real estate and owned a restaurant. He was also a retailer and a motivational speaker.

In addition to his wife, he is survived by two stepchildren, Joseph and Lindsay Curtis of Wilmington, N.C.; and two sisters, Linda Brown of Sanford, N.C., and Pat Harper of Kerr Lake, N.C.

James T Clack