John "Jack" Duff age 75 of Beloit passed away Wednesday September 21, 2022 in his home surrounded by family. Jack was born November 22, 1946 to the late Thurman and Lela (Schultz) Duff. He graduated from Beloit Memorial High School and attended the Milwaukee School of Engineering before enlisting into the U.S. Navy. He was a proud Vietnam Veteran. He married his love, Linda (Wittchow) Duff, on October 25, 1969 in Berlin, WI. Jack was a longtime member of St. John’s Lutheran Church in Beloit and co-owned and operated Beloit Frame and Axle for many years with his brother Warren.
Known for his sense of humor and funny stories, he was a practical joker with an infectious laugh and generous heart, never hesitating to help people out. An avid Packer and Nascar fan, he also enjoyed golfing and hunting with friends including longtime sidekick, Tom Miller, along with his beagles Sadie and Daytona. A proud Papa, he loved watching his grandchildren excel in all their activities. As a dynamic mechanic and fixer of all things he had a passion for working on cars and especially enjoyed being the pit crew chief for his grandson.
Jack will be greatly missed by his wife of 52 years, Linda; his three children, Lesia (Rodney) Burzinski, Leslie (T.J.) Vincetich & Jason (Sunny) Duff; his eight grandchildren, Lynsey, Rebecca (fiancé Riley), Rachyl, Tyler, Sarah, Sydney, Emma, and Laura; his brother, Warren (Norma) Duff and many nieces, nephews, cousins, extended relatives, and close friends.
He is now at peace joining his parents, twin brother, Jerry Duff, and brother, Don (Sharon) Duff.
Special thanks to the many family members and friends for their support, including Jeff and Bernadine Crall, and those who cared for him at Beloit Memorial Hospital, as well as Agrace Hospice for their compassionate care.
A Funeral Service will be held at 11:00 a.m. on Friday, September 30, 2022 in the BRIAN MARK FUNERAL HOME, 1000 Inman Parkway, Beloit with Rev. Daniel Eddy officiating. A Memorial Gathering/Visitation will be held in the Funeral Home from 9:00 a.m. until the time of service where friends are encouraged to share their special memories. Full Military Burial Rites to follow in Milton Lawns Cemetery. In lieu of flowers, a memorial is being established in Jack's name.