San Francisco, Sep 3 (IANS): Ford Motor has issued a recall notice of nearly 42,000 Super Duty F250 and F350 trucks in the US over a mechanical issue that can increase the crash risk.

According to the National Highway Traffic Safety Administration (NHTSA), the left rear axle shaft on affected models "may have been improperly heat-treated" during production and may break.

The recall includes 2023 models equipped with single rear wheels and a 10.5-inch rear axle shaft.

"A broken rear axle could result in a loss of motive power and inability to hold the vehicle in park. If the parking brake is not applied, this could result in the unintended vehicle movement, increasing the risk of injury or crash," noted NHTSA.

The failures were brought to Ford's attention on August 10 after the US-based Kentucky Truck Plant identified the problem through warranty claim monitoring, according to the notice.

"Two axle shafts returned through warranty were sent to Ford's metallurgical lab for failure analysis," the NHTSA report said.

"Laboratory analysis determined that the axle shafts did not meet Ford’s torsional yield and case depth design specifications in the fractured area. Each of the warranty returned parts had fractured at approximately 44 mm from the flange, indicating an area of incomplete induction heat treatment," it added.

By August 14, seven warranty reports had been linked to the axle shaft problem. On August 18, Ford's Field Review Committee approved a field action.

In July, Ford issued a recall notice for 8,70,701 F-150 trucks in the US that could potentially experience a wiring-related problem with their electric parking brakes.

In a safety recall report to the NHTSA, the automaker said the rear axle wiring harness bundle may contact the rear axle housing in the affected vehicles, leading to unexpected activation of the electric parking brake.