Ford Motor Company has issued a recall for more than 11,000 of its 2009 model year Ranger pickup trucks.

The 4x2 two-wheel drive versions -- undriven front wheels -- may have been fitted with improperly heat treated front wheel spindles. The spindles may fatigue to fracture "without warning" causing a wheel-off situation with the bearings, spindle and wheel.

The trucks were all built at the Twin Cities Assembly Plant between August 22 and October 13, 2008. However, they are not produced in VIN order, so a specific VIN sequence cannot be applied to this recall. Instead, the trucks must be individually inspected for their spindle batch and date code.

Ford found the first defects in September when two trucks being shipped by rail arrived at their destination with failed spindles and collapsed suspensions. However, metallurgical, in-service, and bench testing did not immediately repeat the failure or identify the problem. Eventually, an in-depth Tier 1 and Tier 2 vendor audit turned up the fact that a few spindles produced on some dates may have been improperly heat treated.

The Ranger is produced with both coil spring and torsion bar front suspension. Approximately 87% of the problematic knuckes are on coil spring-equipped trucks and 13% on torsion bar trucks.

Ford said it is not aware of any failures from the in-service fleet to date.

The National Highway Traffic Safety Administration recall is 09V040000.

Ford's recall is 09S07.