Seven more cases of cracked clutch housings have been found in large vehicles made by Mitsubishi Motors Corp. and its spun-off maker, Mitsubishi Fuso Truck & Bus Corp., since a recall was announced in May, it was learned Wednesday.
Two trucks featuring cracks of this kind had already been confirmed.
The latest discovery suggests little progress has been made since the recalls were announced.
Six of the vehicles in the latest cases were rendered unoperational and had to be towed, Mitsubishi Fuso officials said.
The company said last week that a manager in charge of the recall had attempted to cover up the cracks found in the first two trucks. The manager was fired Tuesday.
Hideyuki Shiozawa, head of Mitsubishi Fuso's quality and technology headquarters, said the latest findings are the result of a delay in paperwork and confirmation from the firm's dealers. He said there was no attempt to cover up the latest cases.
In one of the seven cases, the clutch housing of a truck that broke down on National Highway No. 1 in Shizuoka Prefecture on May 29 was fractured. The ensuing vibrations made it impossible for the truck to be driven any further, according to the officials.
In Saitama Prefecture on June 24, another truck suffered a fractured transmission case.