A list of defective components submitted by Mitsubishi Motors Corp. to the transport ministry in 2002 includes a reference to flawed rear-wheel hubs.
The ministry overlooked the reference at the time, however, meaning that recalls of trucks and buses with defective rear-wheel hubs were delayed until April this year, ministry officials said Monday.
The defect is not the same as the one in the front-wheel hub that caused a fatal accident involving a Mitsubishi vehicle in Yokohama in 2002.
The Land, Infrastructure and Transport Ministry obtained the list in June 2002 during a regular inspection of the automaker. It was was compiled on the basis of complaints filed by users of Mitsubishi Motors trucks and buses.
The rear-wheel hub defect went unnoticed because it was given the lowest priority ranking by the automaker, the officials said.
“We cannot check all the information during inspections. We have limitations because we make plans to check starting with prioritized areas,” one of the officials said.
In April, Mitsubishi Fuso Truck & Bus Corp., which was spun off from Mitsubishi Motors in 2003, said it would recall some 9,100 large vehicles manufactured between December 1989 and December 1990, along with around 1,500 buses produced between June 1990 and February 1991.
Rear-wheel hubs made during these periods are thinner than usual and could rupture, according to Mitsubishi Fuso. With the first rupture having been uncovered in September 1990, 65 such incidents had occurred by the time of the recall.
Earlier this year, the automaker recalled some 112,000 large vehicles with defective front-wheel hubs. More than 50 accidents have seen the front wheels of Mitsubishi vehicles detach while in motion, including the January 2002 accident, in which a wheel killed a woman and injured her two young sons.
The ministry plans to compile measures aimed at tightening inspections and improving inspection procedures, partly because the automaker provided false reports on defective front-wheel hubs.