Nissan said the problem originates with improperly sealed anti-lock braking system (ABS) sensors. Water can enter the rear axle housing via these wheel speed sensors, eventually contaminating the axle bearings.

Once the axle bearings are contaminated, corrosion, leading to bearing failure, can result. Nissan said that when this happens, the bearing failure can be such that the wheel assembly separates from the vehicle.

The U.S. National Highway Traffic Safety Administration (NHTSA) was informed by Nissan that in the recall, dealers will inspect for water intrusion and any affected components will be replaced. The ABS sensors will be resealed to prevent water intrusion.

Nissan did not indicate what procedure dealers would use to determine if contamination had occurred, nor did they address the problem of latent failures. Bearing damage due to hydraulic contamination is rarely detectable in its early stages without disassembling the bearings down to the rolling elements and bare races. In fact, contamination usually is not and cannot be diagnosed until the very late stages of failure, especially in an auto shop environment. Nissan is not explicitly offering extended warranty protection to cover rear axle bearing failures which might occur in the future.

Owner notification is set to begin January 15, 2003. The NHTSA campaign number for this recall is 02V299000; the text is available at http://www.nhtsa.gov.