The automaker, a unit of Italy's Fiat SpA, said steering tie rods may have been misaligned during assembly or service and could fracture on an estimated 453,500 of those trucks. The tie-rod assemblies will be replaced at no charge, beginning in January.
Three groups of trucks are being recalled. The largest recall covers an estimated 842,400 Ram 2500 and 3500 trucks from model years 2003-2008, of which an estimated 116,000 may have defective tie rods.
The two smaller groups include 294,000 Ram 2500 and 3500 pickups from model years 2008-2012 and Ram 1500 4x4 Mega Cabs from 2008, as well as 43,500 Ram 4500 and 5500 4x4 chassis cabs from 2008 to 2012.
Chrysler said it is aware of six accidents and two injuries on Ram 2500 and 3500 trucks from model years 2008-2012, and one additional accident with no injuries on the other models.
Replacement parts for the Ram 4500 and 5500 models may not be available until late 2014, Chrysler said. Dealers in the meantime will inspect those vehicles and realign the steering components if necessary, it said. Most of the trucks being recalled - an estimated 968,000 - are in the United States. Another 157,000 are in Canada, 37,100 in Mexico and 18,000 outside North America.