John H. Hendrickson

John Holver Hendrickson, age 80, passed away peacefully in the early hours of Saturday, January 17, 2026, in Waukesha, Wisconsin.

John was born on February 16, 1945, in Waukesha, to Glen and Josephine (née Nader) Hendrickson. After graduating from high school, he attended Milwaukee Vocational and Adult School (now Milwaukee Area Technical College), where he earned a diploma in Diesel Engines. In 1964, John began a remarkable 47-year career with Inland Detroit Diesel–Allison. Throughout his career, he was an active member of the Allison Guild, and his technical knowledge and dedication earned him advancement to the position of Allison Transmission Regional Service Manager. He retired in December 2011.

John married his beloved wife, Sonja, on August 12, 1972 in Menomonee Falls. Together they shared 53 years of marriage. John’s lifelong passion was restoring, customizing, and perfecting vintage cars. He could often be found in his shop, meticulously working on his street rods or his motorcycle, guided by impeccable craftsmanship and an unmistakable eye for detail.

John is survived by his devoted wife, Sonja (née Heaney) Hendrickson; his daughter, Angela Johnson; his son‑in‑law, Kyle Johnson; and his cherished granddaughter, Vivienne Johnson.

He was preceded in death by his parents, Glen and Josephine Hendrickson, and his sister, Glenda Herro (Hendrickson).

A private visitation will be held on Friday, January 23, 2026, at St. Joseph Cemetery, S22W22890 E. Broadway, Waukesha, WI 53186, in the Cemetery’s Chapel. No service will be held. Entombment will take place immediately following the visitation.