ARLINGTON, Texas — Every day at the General Motors Co. assembly plant, harried workers pull 15 of their freshly built sport utility vehicles off the line and climb all over them.
It's not meant to be fun. They check the big vehicles high and low for fit and finish, squeaks and rattles, air and water leaks, and other problems — and typically find few flaws, despite the plant's frantic pace since January.
But as surviving domestic auto plants here and elsewhere continue to stretch their production capacities with month after month of 50-hour weeks, they may test the limits of their quality-control systems.
"Right now, what's going on is everyone is really stretching their plants — and hopefully not to the breaking point," said David Cole, chairman of the Center for Automotive Research in Ann Arbor, Mich. "I don't think they will. But until manufacturers get more comfortable with the direction of the economy, they won't add capacity."
Workers at the GM plant here are "very tired" after six straight months of overtime — 50 hours one week, followed by 59 the next, said Enrique Flores Jr., president of United Auto Workers Local 276, which represents most of the 2,400 employees at the plant.
"We hear it all the time," Flores said. "People are tired, and they wonder how they're going to make it another week."
But he and others say the weary workforce is still turning out high-quality SUVs — an absolute requirement for survival these days. Thanks to modern assembly processes, lots of pre-assembled components, automation and computerized quality monitoring, a tired plant can be just about as efficient as a fresh one, plant and industry officials say.
Two of Arlington's SUVs recently swept their categories in the J.D. Power & Associates Initial Quality Survey: The Chevrolet Tahoe was the top large SUV and the Cadillac Escalade won best large premium SUV.
"Our people take great pride here in what they build, and those [awards] still mean a lot to them," plant manager Paul Graham said. "But they are also validation by our customers that we are building SUVs right."
The plant is on the cutting edge of the lean new business model that most assembly plants in the U.S. have adopted. After months of downtime during a terrible 2009, the plant — now GM's only full-size SUV factory — is running pretty much flat out to replenish dealers' inventories, and it has been on overtime longer than most auto factories.
Last year, dozens of plants nationwide closed, idling thousands of workers as GM and Chrysler declared bankruptcy.
Although the economy continues to sputter, demand for new vehicles is slowly increasing, and most automakers are scrambling to rebuild inventories with fewer plants and workers.
So far, there is scant evidence that the grueling overtime is diminishing hard-won improvements in domestic quality. In fact, for the first time in 24 years, domestic automakers had fewer flaws on average than imports in the recent J.D. Power survey.
"There's no reason to believe that this average 5.5% increase in quality that we've seen each year won't continue" at domestic plants, said David Sargent, vice president of global vehicle research at J.D. Power. "The real test may come when a plant that has been on lots of overtime has to start building an all-new vehicle. But we don't think this will be a problem."
That wouldn't have been true 20 years ago. Back then, autoworkers welded bodies together — a hot, tough job crucial to the assembly of a car or truck.
If bodies aren't straight and true, all the other components that are installed as the vehicle moves down the line will end up being slightly off — resulting in vehicles with rattles or air leaks or worse.
"Unfortunately, the guys doing the spot-welding usually started wearing down first when you worked a bunch of hours for months on end," said Cole of the Center for Automotive Research.
Now, robots perform those arduous tasks. In addition, many of a vehicle's major parts — dashboards, seat assemblies and electrical components — are pre-assembled by suppliers and delivered to the plants.
Still, the work is far more strenuous than a desk job. The Arlington plant technically went to a four-day, 40-hour work week last year but has yet to work one this year. The plant is generally in operation Monday through Friday one week and Monday through Saturday the next.
"It's a long week, but I think people recognize we need to meet customer demand," said Graham, the plant manager.
He said he receives "loads of data" on quality at the plant and none — including warranty reports from dealers — indicate any big problems.
"I don't know that you see any more issues on overtime than you do normally," Graham said. "You've got more hours and you build more trucks. But you adjust. You deal with it."