The National Highway Traffic Safety Administration is investigating a potential fault with the steering assemble in 500,000 Ford cars following reports of crashes.

The National Highway Traffic Safety Association is investigating Ford's discontinued fleet of about 500,000 big sedans due to a steering problem, which jams completely  elevating the risk of a crash

The safety officials' investigation revealed the problem to be with the heat shield in the steering section that can rust and get jammed. This prevents the steering from turning or requires excessive force, according to NHTSA's official review of the investigation. The recall includes Ford's Crown Victoria, Mercury Grand Marquis and Marauder models manufactured between 2004 and 2007, all of which are no longer in production. The Mercury brand was discontinued in 2011 and the Crown Victoria is one of Ford's popular vehicles with law enforcement officials and taxis using them widely.

The authorities are not aware of any fatalities but received five complaints and one injury related to the problem. The NHTSA reported one accident where the steering jammed on a highway ramp and resulted in a rollover crash. The driver suffered an injury.

Earlier in May, Ford issued a voluntary recall of 1.39 million small and full-size SUVs to fix faulty power steerings. The car maker also issued six safety recalls just this month, involving more than 100,000 vehicles in North America.

The auto industry has been flooded with recalls lately, mainly after GM's controversial ignition switch recall from earlier this year. Ford has recalled more than 3 million vehicles while GM has recalled some 30 million vehicles this year.