Pickuptrucks.com reports that a crack can form in the rear joint, causing the driveshaft to come loose from the truck. Obviously, this defect will only affect four-wheel drive models, so standard two-wheel drive Tacomas are left out of the recall.
According to Brian Lyons, Toyota's head of safety communications, "Most of the vehicles [included in the recall] are in the pipeline in Toyota's distribution system or on dealer lots."
Affected owners can contact Toyota at 1-800-331-4331 for more information, and Toyota dealers will perform a ten minute visual inspection of the trucks. Naturally, if they find a fault with the prop shaft assembly, it will be replaced free of charge.