Fahnhorst's younger brother Jim Fahnhorst played linebacker in the USFL and for the 49ers from 1984 to 1990. The brothers were teammates on the 1984 49ers team that won Super Bowl XIX and finished with a 15–1 record.
Personal life
Fahnhorst married Susan Kluska in 1974. They had three daughters, Tiffany, Brittney, and Courtney. Tiffany is a financial advisor in Minnesota.[2] Courtney is a doctor in Jacksonville, FL.[3]
Fahnhorst retired from pro football because of a neck injury that caused him to miss nine games during the 1987 season. He moved to Minneapolis to work as a stockbroker.[1]
Fahnhorst received a life-saving kidney transplant in 2003.[4]