Fiat Chrysler said Friday that it is recalling more than a half-million heavy-duty Ram trucks to fix a problem that can cause the wheels to fall off.

The recall covers certain 2012 through 2021 Ram 3500 heavy-duty pickups, and Ram 4500 and 5500 cab-chassis vehicles, mainly in North America. The trucks have dual rear wheels and flanged lug nuts.

Fiat Chrysler, now owned by Stellantis, said some service and owner's manuals had the wrong torque specifications for tightening the lug nuts that hold the wheels to the hubs. If the nuts were tightened too much, the wheel studs could be damaged and wheels could come off.

The company said that it doesn't know of any crashes or injuries caused by the problem. Fiat Chrysler says the wheels were tightened properly at the factory, so the only affected vehicles would be those that have had wheels removed for service.

Dealers will correct the manuals and inspect and replace wheel studs if needed. Owners will be notified within eight weeks.