close
April,15 2004

Mitsubishi Fuso files
heavy-duty truck and large bus rear hub recall report


Mitsubishi Fuso Truck & Bus Corporation today filed with the Ministry of Land, Infrastructure and Transport a recall report related to rear hubs on heavy-duty trucks and large buses. The recall covers a total of 21,700 vehicles: 19,900 heavy-duty trucks (some models excluded) produced between August 1989 and June 1992; and 1,800 buses produced between May 1990 and November 1992.

The vehicles have been recalled because the use of too thin a gauge of metal in the hub flange base results in structural weakness. This weakness can lead to the formation of cracks in the hub when operation of the vehicle involves frequent and repeated turning maneuvers. On hubs in which this weakness is compounded by improper machining of the flange base, loading stresses can concentrate in this area and speed up the development of cracks. If the vehicle is continued to be used in this state, such cracks can grow and in a worst case situation lead to the hub fracturing and making operation of the vehicle impossible. Because rear hubs differ structurally from front hubs, there is no likelihood of wheel detachment in the event of a rear hub fracture.

Mitsubishi Fuso is bolstering its hub replacement organization by boosting hub production and by sending personnel to sales companies to help in the hub replacement operation. It will take until October to supply dealerships and repair shops with the necessary number of replacement hubs and it will take time to verify the strength of current hub. As a provisional measure, recalled vehicles will be inspected and: (1) where cracks in the rear hubs are found the hubs will be replaced immediately; (2) if no cracks are found the owner/operator will be informed of this and will be urged to take the greatest care in the way he operates his vehicle.

Mitsubishi Fuso filed with the Ministry on March 24 a recall report covering the front hubs on heavy-duty trucks and large buses. In the process of preparing the filing, reports on similar hub-related defects came to light. These showed that there had had been an increase in the number of defective rear hubs on heavy-duty trucks and large buses reported by dealers since 2002. 21 cases occurred till 1991 but because investigations showed that the vehicles involved had clearly been operated in an overloaded state, the company judged that a recall was unnecessary. However, when a further 16 cases were reported in 2002, investigations showed the primary cause to lie in a structural weakness in the hub due to the use of too thin a gauge of metal and that accumulated metal fatigue over many years of operation had led the hub to fracture. In the interests of preventing similar accidents, Mitsubishi Fuso therefore decided to file a recall report covering rear hubs.

The recall report filed with the Ministry today comes some 10 years after the first dealer report on a defective rear hub and Mitsubishi Fuso regrets the delay in taking action. In the event of any defects arising in future, Mitsubishi Fuso undertakes to formulate and introduce appropriate countermeasures with all possible speed as it continues to work with all sincerity to further improve road and traffic safety levels.

As to the overseas market, Mitsubishi Fuso will choose the best way in consideration of each market regulations and conditions.

close