Dec. 20, 2000
By TIMOTHY AEPPEL, JOSEPH
B. WHITE, MILO GEYELIN
and STEPHEN POWER
Staff Reporters of THE
WALL STREET
JOURNAL
Bridgestone/Firestone Inc.'s four-month probe into the root cause of why many of its tires failed has pinpointed a number of manufacturing defects, but also concluded that the tires inflated to the recommended pressure had a narrower margin of safety than previously thought.
Firestone has halted production of some of its lines of tires that were recalled as part of a massive recall of 6.5 million tires in August, and plans to redesign some of its manufacturing techniques to stop the problems. And Ford Motor Co., on whose Explorer sport-utility vehicles most of the recalled tires were mounted, in September boosted its recommendation for tire inflation pressure from 26 pounds a square inch to between 26 and 30 PSI.
Still, Firestone's investigation concluded that the left rear tires on Ford's four-door Explorer would be overloaded at 22 PSI, increasing the likelihood of intense heat buildup within the tires that could lead to tread separation. Given that tires lose an average of one pound a square inch each month, the overloaded level would be reached in only four months, unless inflation pressures are checked. As such, Ford's initial recommendation that tires be inflated to 26 PSI doesn't provide enough of a safety margin, Firestone concluded. Ford, which maintains that low pressure shouldn't start to generate enough heat to cause tread separation until the pressure falls well below 20 PSI, strongly disputes Firestone's conclusion.
Firestone also contended that Ford's specification for the tires didn't change between the early 1990s and the middle of the decade, even as the Explorer increased in weight. The added weight also puts undue stress on the tires, causing them to deteriorate, Firestone says.
Ford disputes that the weight of the Explorer contributes to the tire failures.
Firestone's study appears positioned to shift some of the responsibility and thus legal culpability for the tire failures onto Ford. Ultimately who is to blame and to what degree will play out in courtrooms around the country, as rollover suits alleging wrongful death and personal injury against the two companies proceed to trial. Firestone is the U.S. unit of Japan's Bridgestone Corp.
"They're clearly talking about Ford in connection to the tires, and they're saying Ford has some liability here and some responsibility," said Mike Eidson, a plaintiffs' lawyer in Coral Gables, Fla., who specializes in rollover suits against Ford. "It's going to have to work itself out in the courts."
While both companies clash on these two issues, one area of unanimity is that the August recall is sufficient and shouldn't be expanded to include other Firestone tires. Sales of both Firestone tires and Ford Explorers have been hurt since the August recall, and both companies appear to be concerned about potential damage to their businesses from an expanded action.
Officials at the National Highway Traffic Safety Administration expect to determine by next March whether the Firestone recall should be expanded to include other models and sizes of tires. The agency is under pressure from Congress to avoid a repeat of its performance before the August recall, when NHTSA staffers missed signs that the tires were failing in unusually large numbers. Failures of Firestone tires are allegedly linked to 148 deaths in the U.S. and more than 40 overseas.
Ford spokesman Ken Zino disputed Firestone's assertion that the auto maker's recommended 26 PSI inflation specification diminished the Explorer's margin of safety.
"We would go back to the Goodyear experience," he said. Between 1995 and 1997, Ford equipped about 500,000 Explorers with Goodyear tires that according to Ford show no signs of unusually high occurrences of tread separation. "Properly made Firestones aren't having these issues," Mr. Zino said. He said Ford's investigators concluded that the 26 PSI standard wasn't an issue, since Goodyear tires with the same inflation standard and a similar design didn't show the same failure patterns.
Firestone, Mr. Zino added, hasn't presented Ford with any data to back up its conclusions about the potential hazard posed by the Explorer's weight and the relatively soft inflation specification.
Firestone said that based on testing done at the company's proving ground, "it appears the vehicle load levels, when coupled with the tire pressure initially specified for the Ford Explorer with the P235/75R15-size tire, resulted in a tire that was approaching the limits of its load-carrying capacity."
Firestone noted differences in safety margins based on specific Explorer models. While the 1998 through 2000 four-door Explorers could reach their load-carrying capacity after dropping a mere four pounds a square inch, the two-door models made from 1991 to 2000 would have to see tire pressure drop to as low as 18 PSI to reach the comparable danger zone, said the company's engineers.
Ford's own preliminary inquiry, also released Tuesday, concluded that the tire failures involve a "combination of manufacturing factors and the reaction of the tire design to field operating conditions including hot weather and very low tire pressure."
Firestone agrees with Ford on several of these points. The tire maker found problems in the process used to make skim stock at its Decatur, Ill., plant, where most of the recalled tires originated. Skim stock, a rubber used to bond together the steel belts inside the tires, is made in giant mixers, which combine rubber together with chemicals such as antioxidants. At Decatur, this mixture is churned out as pellets, while other Firestone plants extrude long sheets of rubber. Lubricants are then added. Firestone discovered that the pellets picked up more lubricants, thus altering the chemical properties of the skim stock, making it weaker. It is now making changes in that process.
Firestone also found the "shoulder pockets," or the hollowed-out spaces that run around the edges of the tread on the tire's shoulder, were much deeper on some of the recalled tires. Deep cracks tended to form at the bottoms of the pockets and could become the starting points for later tread separations.
Firestone's conclusions about Ford's role in the tire failures don't mention the design of the Explorer itself and the part that it might play in the high number of fatal rollovers the vehicles have experienced when equipped with Firestone tires.
One indication of how juries react to Ford and Firestone's dueling reports -- as well as Ford's liability for rollover accidents in Explorers overall -- is expected to come early next year. A personal-injury suit naming Ford and Firestone is set to begin trial Jan. 8 in state court in Corpus Christi, Texas, on behalf of Donna Bailey, a 43-year-old single mother who is now a ventilator-dependent quadriplegic following a rollover in a Ford Explorer equipped with Firestone Wilderness tires last March.
The case is particularly noteworthy because the tires on Ms. Bailey's Explorer were made at a Firestone plant in Wilson, N.C., not at the Decatur, Ill. plant that both Ford and Firestone have isolated as the source of the tire maker's manufacturing problem. That means the Firestones on Ms. Bailey's Explorer would not have been among the 6.5 million recalled last August. "These are the same tires that Ford and Firestone are using on vehicles today," said Ms. Bailey's lawyer, Tab Turner, of Little Rock, Ark., a specialist in Ford rollover cases.
Joan Claybrook, a former NHTSA administrator who heads Public Citizen, a Washington-based consumer advocates' group, said Firestone's findings suggest "a lethal combination" involving the Explorer and the tires.
"To suggest Ford has no liability is ridiculous," said Ms. Claybrook, whose group has called on the NHTSA to expand the recall. "Tire companies and auto companies expect tires to fail -- that's why they give you a spare and a jack. But the Ford Explorer can't tolerate this kind of failure because where there's been tire failure, there have been rollovers and deaths."