Ford is telling the owners of 33,428 additional Ranger pickups in North America not to drive them because their Takata air bag inflators may present an extreme danger.
The company says its investigation has found test results showing that inflators in the 2006 trucks have a higher risk of exploding and hurling shrapnel than other recalled Takata inflators.
Takata uses ammonium nitrate to create a small explosion to inflate air bags.
But the chemical can deteriorate and burn to fast, blowing apart metal canisters.
Dealers will pick up the Rangers from owners and take them in for repairs.
The additional Rangers were built between Aug. 5 and Dec. 15, 2005.
Last month Ford told 2,900 Ranger owners not to drive them after finding out that a West Virginia man was killed by an exploding inflator.