It upset Cora Nix, the Chamber of Commerce manager here, when she heard that the Washington Metro subway cars aren't working all that well.

"Are you sure the problems aren't because of something they did up there in Washington?" she asked, accusingly. "We're very proud that we built those cars."

Right now, the last of Metro's original order of 300 subway cars is nearing the end of the assembly line at Winder Transportation Systems, a subsidiary of Rohr Industries, and at one time the largest single employer in Barrow County, Ga.

That 300th car is the last one Rohr will ever build. The factory here was sold two weeks ago. Almost 600 people were once employed here. Now there are 150, and the number is decreasing every week.

Rohr is getting out of the transit car business after having lost its shirt on the Washington contract. The company claims that its losses on the Metro cars are $45.8 million: it has filed a $48.3 million claim against Metro.

Whatever the merits of the claim and despite the fact that Rohr is setting off assets, its spokesmen insist that the firm is financially able to stand behind the Metro cars for the duration of the warranty period, which is as long as seven years in the case of the newest cars.

"As far as the financial health of the company is concerned, there is no reason for us not to fulfill our obligations," said Larry I. Peeples, director of corporate public affairs for Rohr."We have an obligation to Washington."

Rohr is cooperating in solving the problems that have plagued Metro subways cars since full-scale rail operations began with the opening of the Blue Line July 1, according to Metro general manager Theodore Lutz.

Metro has no future in Winder. The vast, L-shaped building that was fabricated here for the construction of transit cars is now less than half-full. Boxes filled with tiles are stacked high on the desks of what were once busy engineering offices. The test track that runs for almost a mile behind the plant is used almost exclusively to store completed cars before they are shipped to Washington.

The atmosphere is like that of a living room of an old family residence that has been sold. The books have been packed and the furniture pushed aside. Everyone is waiting for the moving van.

"We cried," said Nix, when Rohr announced in June, 1976, that it was getting out of the transit car business. "Rohr was an excellent citizen and we hate to lose them. They were involved in community activities and their plant manager served as chamber president."

There was also a dramatic, negative impact on morale along the production line. According to John Nicita, the Rohr engineering director at Winder, absenteeism shot up and engineers and other technicians began bailing out as quickly as they could find jobs elsewhere.

"I approached management," Nicita said, "and told them we had to do something."

A bonus system was devised that was lucrative enough to hold the engineers until Rohr wanted them to go. Assembly line employees were given a $120-bonus after three weeks of perfect attendance plus a weekly bonus for each perfect week after the third. That solved the absentee problem.

The last of the Metro cars has "turned the corner" in the factory. That means it has traveled the short leg of the "L." Two walls and the ceiling have been joined and cutouts have been made for ducts, windows and the double doors.

A giant crane that runs on tracks picks up the car at this point and swings it to the long leg of the L. The car walls and ceiling are joined to the floor and components are added as the car moves down the line. It undergoes a number of tests along the way, including one for water tightness. The car is carried along the line by the crane.

At the end of the 1,000-foot-long leg, in a restricted area set off by a chain-link fence, the cars are fed electricity and given their first tests under power before they move to the test track outside.

The last of the cars will clear the line sometime in November.

Rohr had been in Winder since the mid-1950s, where it fabricated aircraft engine packages. When it diversified into the transit car business, it decided it needed an East Coast plant, and Winder was chosen.

Business prospects looked good. Rohr had already won the contract for San Francisco's Bay Area Rapid Transit cars (which were fabricated in the West) and new rail systems were planned for Baltimore, Miami and Atlanta as well as Washington. Furthermore, there was the prospect of business from Amtrak as new equipment was purchased for expanding rail passenger business.

Rohr won the Washington contract in June, 1972, with a fixed-price bid of about $300,000 per car. Metro officials were astonished that it was so low. But other contracts just did not develop for Rohr as federal funding of new rail systems became more uncertain because of rapidly escalating costs - most obvious in San Francisco and Washington.

It was obvious that Rohr was in financial trouble on the Metro contract in May, 1975, when the Metro board agreed to advance Rohr $22.5 million to help it solve cash flow problems.

Rohr tried to recoup on the Metro cars by offering them to the new Atlanta system essentially unchanged. But the Atlanta engineers had problems with the Metro design, and were unwilling to accept it without some major modifications that Rohr was apparently unwilling to provide. Rohr did not bid on the Atlanta contract, which went to a French firm for about $542,000 a car. Soon after, Rohr announced it was getting out of the transit business.

Winder has a population of about 9,000 in a county of about $20,000. Although it is rural and located in the South, it does not appear to be an impoverished area, and the unemployment rate for the county is one 4.6 per cent, well below the national average of 6.9 per cent.

Several new manufacturing plants are opening or expanding in the town, and an interstate highway has made Atlanta accessible for the set that doesn't mind commuting 50 miles one way. "That all want six-acre farms," Nix said.

Rohr has reached a tentative agreement to sell the buildings to Portac, Inc., an Illinois farm that fabricates special-use rail cars and has $127 million in back order. By the middle of next year, a Portac spokesman said, the new owners hope to begin operations. They will eventually employ up to 500 people. But the huge investment in special equipment for Metro cars will stay with Rohr.

For people like Mary Daniel, who came to Rohr four years ago to work on the assembly line and became "one of the best inspectors in the place" within months, according to Nicita, the end of the Metro contract means no job.

I'll have do draw unemployment, at least for awhile," she said. "I'm going to try and go back to school."