John Dodge died from pneumonia on January 14, 1920 In New York City, where he and his brother had attended an auto show. Horace Dodge died less than a year later in Palm Beach, Florida on December 10, 1920.
The Dodge children were neither able nor willing to manage the firm after their fathers' deaths, although the two widows made a weak effort to do so. The works manager, Frederick J. Haynes, became the chief executive officer from 1920 until 1925. The firm continued to grow during these years, with
output reaching a plateau of about 200,000 cars in 1924-25. However, they were still well short of Ford's production of 1,675,000 cars and Chevrolet's 470,000 units for 1925. On May 1, 1925 the Dodge heirs announced the sale of the firm to the New York investment bankers Dillon, Read & Company for $146 million. Dillon held the property for three years before selling it to Walter P. Chrysler in May 1928 for $170 million.
Plant expansion continued during the 1920s, but at a much slower pace than before. Seven new buildings and one major extension added another 1.2 million square feet of space to the existing area of about 3.3 million square feet. A second Assembly Building, constructed in three segments in 1923-25, was easily the most impressive new structure. Located south of the original Assembly Building and running parallel to it, the new building was a six-story reinforced concrete design, 100 feet wide and 1,080 feet long, creating about 700,000 square feet of floorspace for the trim departments. The remaining new construction included a five-story concrete addition (1925) to the Warehouse Building; the narrow four-story reinforced concrete Main Building No, 4, built in 1926 and running parallel to the Forge Shop; three steel-framed buildings -- Heat Treat No. 2 (1925), Pressed Steel Stores (1926), and Maintenance No. 2 (1927) -- all on the northern fringe of the plant; and the Driveway Garage (1927) at the southwest comer of the complex. This was the last wave of construction.
By 1925, Dodge Main incorporated all the major production processes and departments needed to make it a fully integrated automobile manufacturing and assembly plant. Most of the castings and forgings needed to produce the Dodge car were made on the premises, along with all the required pressed (stamped) steel body parts. The machine shops housed 300 automatic screw machines, 60 cold heading machines, 325 gear cutting machines, and 215 grinders. The heat treatment department hardened about 100,000 parts per day. The fourth floors of the Assembly Building and the Pressed Steel Building, as well as the roofs of both, held 54 enameling ovens and an elaborate conveyor system to move parts and bodies through three seperate painting operations. The entire complex was largely self-sufficient: the powerhouse supplied electricity, compressed air, and steam; the Construction Department handled most building and repair projects; testing of raw materials was done in physical and chemical laboratories on the premises; the complex had a staff of 475 tool makers who produced all the jigs and fixtures required; and the plant had its own narrow gauge industrial railroad with four miles of track. Dodge Main was large enough to have its own hospital, laundry, post office, fire department, print shop, photographic department, instrument repair shop, weather bureau (an aid to the enameling operations), restaurant, barber shop, and a police force of 125 men.