The issue in the suspension arm was caused by improper conditions at the steel supplier, the Japanese automaker said, which led to cracks forming on the surface of the steel. According to the defect information report, when the affected vehicles are driven regularly with aggressive acceleration and deceleration, the cracks could spread and lead to the suspension arm separating from the wheel assembly. However, Toyota says that it is unaware of this occurring in any of the recalled vehicles.Owners will be notified of the recall by mail scheduled to begin on July 19. Dealers have already been notified and will replace the parts on the vehicles. In the meantime, owners of the affected RAV4s can visit the NHTSA website to see if their vehicles are included and to get more information.