Ford Motor Co. is recalling approximately 184,000 2011-2012 model-year Ford F-150 trucks and 2012-MY Expedition, Mustang and Lincoln Navigator vehicles in the U.S. because they’re at risk for unexpectedly downshifting.

These vehicles, each equipped with a 6R80 transmission, have a potential problem with the output speed sensor on the transmission lead frame. Under certain conditions, the transmission controls could force a temporary downshift into first gear.

Depending on the speed of the vehicle at the time of the downshift, the driver could experience an abrupt speed reduction that could cause the rear tires to slide or lock up. This condition could result in loss of vehicle control, increasing the risk of a crash, according to Ford.

Ford noted it’s aware of three reports of accidents, but no injuries have been related to this condition.

The Ford F-150 vehicles were built at Dearborn Truck Plant and Kansas City Assembly Plant from Aug. 19, 2011, through March 9, 2012. The Ford Expedition vehicles were built at Kentucky Truck Plant from Aug. 19, 2011, through Dec. 19, 2011. The Ford Mustang vehicles were built at Flat Rock Assembly Plant from Aug. 19, 2011, through Feb. 21, 2012. The Lincoln Navigator vehicles were built at Kentucky Truck Plant from Aug. 19, 2011, through Dec. 17, 2011.

In addition to the vehicles recalled in the U.S., 17,900 vehicles are being recalled in Canada.

Dealers will inspect the powertrain control module for diagnostic trouble codes tied to the issue. If no related diagnostic trouble codes are present, dealers will update the powertrain control module software, which will eliminate the downshift into first gear if an OSS fault occurs, Ford said.

Additionally, as part of the corresponding customer satisfaction program, Ford will provide a one-time replacement of the lead frame at no charge within 10 years or 150,000 miles from the warranty start date.

If related diagnostic trouble codes are present, dealers will update the powertrain control module software and replace the lead frame at no cost to the customer, Ford said.