Preliminary Evaluation PE08-036: TIRE VALVE CRACKS

ON MAY 15, 2008, THE OFFICE OF DEFECTS INVESTIGATIONS OPENED A PRELIMINARY EVALUATION (PE08-036) TO INVESTIGATE THE PREMATURE FAILURE OF DILL AIR CONTROLS PRODUCTS (DILL) SNAP-IN TIRE VALVES BECAUSE OF OZONE CRACKING. AIR LEAKAGE FROM ONE OF THE SUBJECT VALVES IS ALLEGED IN A LAWSUIT AS THE CAUSE OF A FATAL ROLLOVER CRASH OF A 1998 FORD EXPLORER IN NOVEMBER 2007.

THE LAWSUIT CLAIMS THAT THE ROLLOVER RESULTED FROM THE SUDDEN FAILURE OF THE RIGHT-REAR TIRE, WHICH ALLEGEDLY WAS CAUSED BY AIR LEAKAGE FROM A DEFECTIVE DILL VALVE.THE VALVE WAS INSTALLED BY A DISCOUNT TIRE STORE IN SEPTEMBER 2006.

DISCOUNT TIRE IS A CO-DEFENDANT WITH DILL IN THE LAWSUIT.ODI OPENED PE08-036 BASED ON INFORMATION RECEIVED FROM DILL AND DISCOUNT TIRE IN MEETINGS ON APRIL 30, 2008 AND MAY 12, 2008, RESPECTIVELY.IN RESPONSE TO AN INFORMATION REQUEST FROM ODI, DILL INDICATED THAT IT IMPORTS THE SUBJECT VALVES FROM A MANUFACTURER IN CHINA, TOPSEAL AUTOMOTIVE.TOPSEAL'S ROOT CAUSE ANALYSIS TRACED THE OZONE CRACKING PROBLEM TO A CHANGE IN SUPPLIERS OF A CHEMICAL USED TO PROVIDE OZONE PROTECTION.THE PROBLEM AFFECTED VALVES MADE FROM JULY TO MID-NOVEMBER 2006.

DILL INDICATED THAT AFFECTED VALVES SHOULD EXHIBIT VISIBLE CRACKS SHORTLY AFTER BEGINNING SERVICE AND THAT THE CRACKS MAY GROW LARGE ENOUGH TO CAUSE AIR LEAKAGE AFTER APPROXIMATELY 8-14 MONTHS IN SERVICE.ACCORDING TO DILL, APPROXIMATELY HALF OF THE CRACKED VALVES THAT HAVE BEEN RETURNED FROM THE FIELD HAD CRACKS THAT WERE LEAKING AIR. DILL ISSUED AN ADVISORY TO ITS CUSTOMERS (RETAIL TIRE STORES AND DISTRIBUTORS) ON MAY 2, 2008, REQUESTING RETURN OF UNUSED INVENTORIES OF VALVES FROM 2006 PRODUCTION LOTS AND RECOMMENDING INSPECTION PROGRAMS TO DETECT AND REPLACE AFFECTED VALVES.IN JUNE 2008, DILL RELEASED ON ITS WEBSITE PROCEDURES FOR INSPECTING VALVES AND FILING CLAIMS (HTTP://DILLAIRCONTROLS.COM).

DILL HAS ALSO HIRED A LABORATORY TO CONDUCT RUBBER CHEMISTRY AND OZONE RESISTANCE TESTING OF RETURNED VALVES FROM EACH OF THE LOTS SHIPPED FROM THE SUSPECT PRODUCTION RANGE. IN RESPONSE TO AN INFORMATION REQUEST FROM ODI, DISCOUNT TIRE PROVIDED INFORMATION REGARDING AN EXTENSIVE VEHICLE INSPECTION PROGRAM CONDUCTED FROM APRIL THROUGH JUNE 2008 TO DETERMINE THE FREQUENCY OF THE CRACKING CONCERN IN DILL VALVES IN COMPARISON WITH OTHER VALVES USED BY DISCOUNT TIRE FOR VEHICLES THAT RECEIVED NEW TIRES FROM JANUARY 2004 THROUGH APRIL 2008.

THE DISCOUNT TIRE INSPECTION PROGRAM SHOWED THAT DILL VALVES INSTALLED FROM AUGUST 2006 THROUGH JULY 2007, A PERIOD THAT CORRESPONDS TO SHIPMENTS OF TOPSEAL PRODUCTION LOTS FROM THE PERIOD WITH THE PROBLEMS WITH THE ANTI-OZONANT, WERE MUCH MORE LIKELY TO BE CRACKED THAN THE NON-DILL VALVES AND THE DILL VALVES INSTALLED BEFORE AND SINCE.IN JULY 2008, DISCOUNT BEGAN AN OWNER NOTIFICATION PROGRAM TO SEND LETTERS TO CUSTOMERS WHO RECEIVED NEW TIRES FROM DISCOUNT TIRE STORES THAT SOLD DILL VALVES FROM AUGUST 1, 2006 THROUGH JULY 31, 2007.

THE LETTERS NOTIFIED THE CUSTOMERS OF THE VALVE CRACKING CONDITION, DESCRIBED THE POTENTIAL SAFETY RISKS AND OFFERED FREE REPLACEMENT OF THE TIRE VALVES. INFORMATION ABOUT THE DISCOUNT TIRE CUSTOMER ADVISORY CAN BE FOUND AT HTTP://WWW.DTCCARES.COM. THIS INVESTIGATION HAS BEEN UPGRADED TO AN ENGINEERING ANALYSIS (EA08-022) TO FURTHER ASSESS THE SCOPE, FREQUENCY AND SAFETY RISKS ASSOCIATED WITH THE ALLEGED DEFECT.