Upon leaving hockey in 1963, he focused on a career in harness racing. Stewart's father built a track on the family farm and held a horse racing meet each year to entertain the residents of Pilot Mound. He also followed and assisted his father when the elder Stewart acted as a race judge at fairs held in Manitoba. Stewart was actively involved in the sport from the time he retired as a player. He worked as a race timer and held various judging roles during the summers. He was a judge with the Ontario Racing Commission for nearly 30 years where his reputation matched that of his playing days.