After the rebuilds, these locomotives were used through World War II. The first to be retired from active service were numbers 4040 and 4045, both on October 21, 1946; the last to be retired was number 4032 on August 8, 1949. The AC-3ś were Used for Long Freight Runs, and sometimes even Used to pull Passenger/Troop Cars during World War II. All of this class were scrapped soon after retirement.
References
Diebert, Timothy S.; Strapac, Joseph A. (1987). Southern Pacific Company Steam Locomotive Conpendium. Shade Tree Books. ISBN0-930742-12-5. {{cite book}}: Unknown parameter |lastauthoramp= ignored (|name-list-style= suggested) (help)