How long has the Ford F-150's FX4 had a locking rear differential?

An electronic locking rear differential has been standard on the FX4 off-road model since 2009, which is when the F-150 was last redesigned. Previous versions had a limited-slip differential. Among other standard features are four-wheel drive, hill descent control, skid plates and 18-inch wheels.

Rick Popely: Ask.Cars.com

February 2, 2013