GM will phase out one of its six iron foundries.

Citing excess capacity, the auto maker reported that production at its Saginaw Nodular Iron Plant will be reduced beginning this month and will end by summer, 1988. Eventually about 1,800 workers at the Saginaw, Mich., foundry will be displaced, a plant official said. It is the third major foundry closing by General Motors in two years and the third Saginaw plant shut down by GM since 1983. The Saginaw plant produces crankshafts, disc brake housings, steering knuckles, exhaust manifolds and transmission, axle and drive line components.