The National Highway Traffic Safety administration says on its website that lower control arms in the rear suspension can rust and break, possibly causing a crash.
The agency says Chrysler has added the 2006 and 2007 model years to the recall. It now totals nearly 347,000 vehicles. The recall covers vehicles in 20 states and Washington, D.C., where salt is used to clear snow and ice from the roads.
The company knows of no crashes or injuries from the problem.
Chrysler said in March that it was recalling about 200,000 Libertys from the 2004 and 2005 model years for the same problem.
Chrysler says it will inspect the parts and replace them for free if needed.