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Tire Failures and Tread Separations

What You Need to Know About Tire Failures, Defects, and Tread Separations

Tread Separations

Passenger and light truck tire tread separations are an unfortunate by-product of steel-belted radial tire technology


Due to the difficulty in obtaining adhesion of steel to rubber there is a potential for tread separation of all steel-belted radial tires. This is true especially at high speeds in hot weather. Industry records verify that tread belt separations are the most common mode of failure of steel belted radial tires. Separations result from both design and manufacturing defects. Recent examples of this have included the Firestone ATX and Wilderness tires on Ford Explorers, Continental General tires on Lincoln Navigators, the Firestone Steeltex tires on Excursions, and the Goodyear Load Range E tires on 15-passenger vans

There are some alarming similarities between all of the recalled tires in both the failure mode and the causes for failure. It is noteworthy that tread separation problems often first surface in the warmer regions of this country and around the world. We also see the inherent design defects in many steel-belted radial tires exacerbated by underinflation which on some occasions is recommended by the vehicle manufacturer. It is important to note that all manufacturers have suffered steel belted radial tire tread belt separations since the 1970s. Tread belt separations are not limited to Firestone, Goodyear or General tires. There has been extensive tread belt separation litigation involving Cooper tires, Uniroyal-Goodrich tires, as well as other manufacturers.

The results of tread separation can be catastrophic. Tread belt separations frequently cause tire blowouts. Even when the tire does not lose pressure the driver often loses control of the vehicle when the tread and belt separate from the carcass of the tire resulting in vehicle loss of control and rollovers that have resulted in thousands of serious injuries and fatalities.

When the tread comes off of a vehicle at high speed, the driver sometimes hears a loud thumping noise before the vehicle goes out of control. The loss of control can be due to a combination of factors, including friction or braking action as the loose tread piece strikes against or catches on the undercarriage of the vehicle. When a rear tire is involved, this results in a braking action in the direction of the tire failure. When the driver attempts to correct for this braking action the vehicle usually goes out of control in the opposite direction. This is often mistakenly referred to as overcorrection. In truth, it is the normal appropriate reaction to the braking phenomenon experienced by the driver. This sequence of events occurs so rapidly that it is virtually impossible to handle most high speed tread separation failures and resulting loss of control of the vehicle. This was demonstrated by tests of Ford Explorers with Firestone tires in which an experienced test driver, who knew the tread was going to separate, lost control and the vehicle rolled over.

The rollover problem is exacerbated by high-center-of-gravity vehicle designs such as employed in popular sport utility vehicles. The tire design problem can be overcome by use of proper wedges and cushions at the belt edges, an appropriate under tread protecting the steel belt edges, and a nylon overlay design modification known as "safety belts", widely used in tires manufactured for the European market as well as many American tires. Nylon overlays virtually eliminate tread separations unless the tire has a significant design or manufacturing defect. Even then, the nylon overlays will substantially delay failure.

Manufacturing defects can be substantially reduced by appropriate adhesion, proper manufacturing practices, and adequate quality control measures. Some plant practices which contribute to tread belt separation include improper curing, the use of over aged "dry" rubber stock, use of petroleum solvent on tire components prior to vulcanization, moisture or foreign matter cured into the tire, improper repairs, inadequate final inspection and an emphasis on production or quantity over quality and safety. Many plants run on twelve-hour shifts with the tire builders working on a quota incentive system which unduly stresses workers.

We have established through sworn testimony of tire plant workers that tires have been contaminated by everything from chicken bones to live shotgun shells. Other examples of contamination or foreign material have included wrenches, gloves, screws, bolts, small wire, wood, water, sunflower seeds, and all sorts of other contamination that have been cured into tires. We have also learned from plant workers that outside tire inspectors were misled by various means during inspections, including hiding defective tires and showing inspectors the same tire repeatedly once it had passed inspection.

When examining a separated tire one should look closely at the separation interface to determine whether there is any rusty wire, bare wire or brassy wire exposed. Corroded wire is usually evidence of moisture contamination during manufacturing. Bare wire is an indication of a manufacturing adhesion defect. Brassy wire is a strong indication of no adhesion. High resolution photographs should be taken of any exposed surfaces as quickly after the accident as possible to document any exposed wire conditions and the condition of the surface where the tire has delaminated.

Traditionally, the tire industry has attempted to shift the burden for defective tires to the victim in the accident. They assert that tread separations are the result of impact damage or underinflation. In fact, underinflation does not cause tread belt separation in a properly constructed, properly designed tire. However, if a tire has manufacturing or design defects and it is run underinflated, underinflation can accelerate tread belt separation. Unfortunately, it is virtually impossible for the consumer to determine whether a steel belted radial tire is underinflated by visual inspection. It is often difficult, if not impossible for people who are forensic tire experts to determine upon visual examination whether a tire has incipient tread belt separation prior to the actual failure of the tire that causes the steel belt(s) and tread to separate from the carcass.

The potential for underinflation is increased by the air permeability of steel belted radial tires. All steel belted radial tires leak air. Design and manufacturing defects can accelerate this leakage rate. Because of the air permeability of steel belted radial tires almost all tires are run underinflated at some time during the course of their lifetime and, as noted, this is usually not observable by the consumer. Accordingly, the victim is usually unaware that the tire is underinflated and certainly unaware that underinflation will result in tread belt separation which in a properly constructed tire would not occur. Likewise, impact damage does not cause tread belt separation. Impact damage can cause failure of a tire, but it is not a tread separation failure.

Tire manufacturers often claim that damaging information contained in their records is trade secret and should not be disclosed. The truth of the matter is, comprehensive analysis of steel belted radial tires is reported to tire manufacturers by Smithers Scientific Services so that all of the tire manufacturers are routinely provided with the physical properties and chemical makeup of their competitors’ products. Tire manufacturers also reverse engineer their competitors’ products on a continuing basis and are well aware of the composition of tires manufactured by their competitors. They purchase raw materials and tire manufacturing equipment from the same vendors. Accordingly, there is very little bona fide trade secret information that is not known by all tire manufacturers about their competitors’ tires. They all build tires essentially the same way with essentially the same equipment. Tire manufacturers also occasionally build tires for their competitors under the competitor’s brand name.

Unfortunately, unless someone is seriously injured or killed, they have very little recourse against tire manufacturers. Consumers should, however, contact NHTSA to document their accident and should contact a local attorney to see whether it is appropriate to pursue a claim. Increasingly, we are hearing from consumers who are taking action into their own hands and filing small claims against tire manufacturers in local courts. They handle the case on their own because it is virtually impossible to find a lawyer who can pursue a tire claim when there is no serious injury or death.

If you find yourself in the circumstances where you cannot find a lawyer, we strongly urge you to send your information to NHTSA and to your congressman and senator. The tire industry has been able to avoid their responsibility to the public for decades by hiding the extent of accidents, injuries and deaths and by hiding internal records which establish the extent of the tread belt separation hazard throughout the industry. Unfortunately, many courts have unwittingly assisted in this cover-up by granting protective orders which are abused by tire companies. Unless concerned citizens react the tire industry will continue to ignore the problem. If you are an attorney involved in a tire accident lawsuit and have questions about tire defects, tread separations or blowouts, contact Bruce Kaster at (352) 622-1600.