Firestone Probe Focusing on Design Differences

Bridgestone/Firestone Inc., trying to find out why its tires shred, said it is focusing on design differences in its ATX and Wilderness tires and how tires were made at its beleaguered Decatur, Ill., plant. The unit of Japan’s Bridgestone Corp. recalled 6.5 million of both types of 15-inch tires in August because of links to fatal highway accidents. So far 4.8 million of the 6.5 million tires have been replaced. Most of the suspect tires are on Ford Explorer sport-utility vehicles. Bridgestone/Firestone said it also is taking a “hard look” at components such as the interbelt material because that is where treads tend to peel away. The interbelt includes steel cords that are incorporated into two rubber-coated belts that are then combined with a separate rubber strip. On the manufacturing side, the tire maker said it is investigating how tires were made at Decatur. Bridgestone/Firestone said the claims rate for Decatur-made Wilderness AT tires peaked in 1996, the first year the tires were made there. Wilderness claims rates fell in 1997 and continued to decline after that.