Spring Hill Manufacturing is a General Motors factory in Spring Hill, Tennessee. It opened in 1990 as the site for Saturn manufacturing and continued through March 2004 as the sole manufacturing plant overseen by the Saturn subsidiary. After the United Auto Workers ratified a new contract in March 2004, the plant became part of General Motors, but Saturn-only manufacturing lines continued until March 2007. The facility includes a four-cylinder engine assembly plant, auto assembly plant, paint and plastics plant, a Saturn parts warehouse, and a visitors center. In 2005, the plant had a yearly production of 198,142 vehicles. Harbour Consulting rated the Ion line as the tenth most efficient auto plant in North America in 2006.
After GM considered idling or shutting down the plant as part of its restructuring effort, it idled in March 2007 for a 1-year retooling project to produce the 2009 Chevrolet Traverse after receiving incentives from the State of Tennessee. Changes include adding metal stamping and removing the plastics plant (the Saturn production lines used plastic-based panels). General Motors has stated the plant will manufacture various GM vehicles and no longer be dedicated to Saturns.
The vehicle assembly part of the Spring Hill plant was idled in late 2009 when production of the Traverse was moved to Lansing Delta Township Assembly near Lansing, MI, while production of power trains and metal stamping continued. Nearly 2,500 Spring Hill auto workers were faced with lay-offs, buy-outs and early retirement. In September 2011, it was announced that the plant would end its period of idling. In November 2011, GM announced plans for retooling of the vehicle assembly portion of the plant for use as an "ultra-flexible" plant which will initially be used to build the Chevy Equinox and GMC Terrain but will be designed for rapid retooling to other vehicles of similar size.
In 2015, the plant announced that it would be reopening the entire plant's facilities, and would hire locally creating thousands of jobs for the surrounding area. General Motors looks to expand the plant's facilities and influence in the North American and Global Auto industries, and is currently the company's largest plant in North America.
As of 2016, the plant includes vehicle assembly (Cadillac XT5 and GMC Acadia) as well as powertrain, stamping and molding operations..