CBS MarketWatch reports that the National Highway Traffic Safety Administration (NHTSA) has asked for the recall of 600,000 Dodge Durango SUVs and Dakota pickup trucks because of potential suspension problems that could cause front wheels to fall off.

The report said that a DaimlerChrysler spokesman acknowledged the NTSB investigation, but said no recall has been ordered and the company doesn't think the problem "rises to the level of a safety defect," the Associated Press reported.

DaimlerChrysler is planning to respond to the government request next week, AP reported.

The NTSB investigation involves Durangos and Dakotas in the 2000-2003 model years, the AP said.

The federal agency found that upper ball joints, part of the front-end suspension and steering systems, could separate, causing the suspension to collapse and the wheel to fall off. The NTSB investigated dozens of reports of ball joint separation, and several non-injury crashes blamed on the problem, the AP reported.

According to DaimlerChrysler spokesman Max Gates, if an upper ball joint failed it would likely would be at low speed and during turns, the AP reported. Gates said Dakota and Durango owners would hear noise coming from the vehicle well before the joint failed, and a mechanic should spot a potential problem during routine maintenance, the news agency said.