Nearly 1,000 United Auto Workers members initiated a strike at the Dauch Corp. factory in Three Rivers, Michigan.
The facility manufactures axles for General Motors' full-size and mid-size pickup trucks. A prolonged work stoppage threatens to exhaust axle supplies and halt production of GM's most lucrative vehicles.
Union leaders cite stalled wage negotiations as the primary cause for the walkout. The UAW reports that top wages at the plant have declined since 2008.
General Motors is currently monitoring the situation to assess potential impacts on its operations.