Consumer Guide's® Auto Editors have scoured repair bulletins and questioned mechanics to search for commonly occurring problems for a particular vehicle. In some cases we also give possible manufacturer-suggested solutions. In many instances these trouble spots are Technical Service Bulletins posted by the manufacturer, however, we have our own expert looking at additional vehicle problems.

Air conditioner: The air conditioner may intermittently quit working during cruising due to icing of the evaporator requiring installation of a thermostatic switch. (2003-04)

Brake wear: The original equipment brake pads cause excessive dust and revised pads with a different lining material are available, but must be installed on both the front and rear and are not covered by the original warranty. (2003-04)

Clutch: The rear wheels may chatter during low speed turns requiring installation of a revised clutch pack in the limited slip differential. (2003-05)

Headlights: Water may accumulate in the headlight assembly requiring the seam between the plastic halves to be sealed with RTV silicone sealant. If this has been done, black tape to hide the repair will be visible on top. (2003)

Security alarm: The retractable running boards my not extend or may do so intermittently because mud or other debris may collect in their tracks, but the problem may be due to failure of the motor or linkage or a problem with the vehicle security system. (2003-04)

Suspension noise: Vibration, often accompanied by a droning sound, comes from the front halfshafts (axles) during deceleration due to unequal rotational speeds requiring installation of clutch springs in the front differential. (2003)

This table lists costs of likely repairs for comparison with other vehicles. The dollar amount includes the cost of the part(s) and labor (based on $50 per hour) for the typical repair without extras or add-ons. Like the pricing information, replacement costs can vary widely depending on region. Expect charges at a new-car dealership to be slightly higher.

2006 Navigator: Both tires on the driver's side may be damaged, leading to belt corrosion or tread seaperation. Dealers will inspect all four tires and replace any with tread damage.

2006 Navigator: Incorrectly-manufactured automatic-transmission parking pawl guide plate could prevent engaging of "park" position. Dealers will inspect and repair.

2006 Navigator: Windshield wiper motor may not be greased properly, causing a loss of wiper function. Dealers will inspect and grease the motor, if necessary.