The Lincoln Navigator, a flagship luxury SUV, has long been known for its commanding presence on the road and ability to provide a smooth, comfortable ride. The advanced air suspension system is one of the key technologies contributing to its superior driving experience. 

How Air Suspension Works in the Lincoln Navigator

The air suspension system in the Lincoln Navigator improves ride quality, handling, and overall vehicle performance across various driving conditions. Unlike traditional coil spring suspensions, air suspension uses compressed air to support the vehicle’s weight and adjust its ride height.

Basic Principle

At its core, the air suspension system replaces conventional steel springs with flexible air springs or bags. These air springs are typically made of durable rubber and are filled with compressed air. The system can increase or decrease the amount of air in these springs, effectively changing the vehicle’s ride height and characteristics.

Key Components and Their Functions

• Air Springs: Located at the rear axle of the Navigator, these flexible bags contain compressed air and support the vehicle’s weight. They can expand or contract based on the air pressure inside them.
• Air Compressor: This electrically driven unit provides pressurized air to the system. In the Navigator, it’s a single-cylinder compressor specific for the rear air suspension (RAS) system.
• Air Lines: These tubes connect the compressor to the air springs, allowing for the transfer of compressed air throughout the system.
• Solenoid Valves: Each air spring has a solenoid valve that controls the flow of air in and out of the spring. These valves are electrically operated and managed by the air suspension control module.
• Height Sensors: The Navigator uses two ride height sensors mounted on the rear axle. These sensors monitor the vehicle’s height and send this information to the control module.
• Air Suspension Control Module: This is the brain of the system. It receives input from various sensors and controls the operation of the compressor and solenoid valves to maintain the desired ride height.
• Dryer: Connected to the compressor outlet, the dryer contains silica gel to absorb moisture from the compressed air, preventing water damage to the system components.

Operation Process

• Height Sensing: The ride height sensors continuously monitor the vehicle’s position. They output a voltage between 0.5 and 4.5 volts, decreasing as the vehicle rises.
• Data Processing: The Vehicle Dynamics Module (VDM) receives signals from the height sensors and inputs like vehicle speed, steering angle, and load conditions.
• Height Adjustment: Based on this data, the control module decides whether to inflate or deflate the air springs. If inflation is needed, it activates the compressor and opens the appropriate solenoid valves. For deflation, it simply opens the valves to release air.
• Continuous Monitoring: This process happens continuously while driving, ensuring the vehicle maintains its ideal ride height and stance.
• Parked Operation: The system remains active for 40 minutes after the ignition is turned off. During this time, it can deflate at any time but will only inflate once at the end of the 40-minute period. This feature ensures the vehicle maintains a consistent stance even if loads are added or removed while parked.

Benefits of the Lincoln Navigator Air Suspension System

The air suspension system in the Lincoln Navigator offers several advantages over traditional suspension systems:

• Adjustable Ride Height: The system can raise or lower the vehicle’s ride height, providing better ground clearance when needed or improved aerodynamics at highway speeds.
• Improved Ride Comfort: Air springs provide a softer, more compliant ride than steel springs. They can absorb road imperfections more effectively, resulting in a smoother journey for passengers.
• Automatic Load Leveling: The system automatically adjusts to maintain a level stance when carrying heavy loads or towing. This feature improves stability, handling, and headlight aim.
• Enhanced Handling: The air suspension helps ensure predictable handling characteristics in various driving situations by maintaining a consistent ride height regardless of load.
• Reduced Noise, Vibration, and Harshness (NVH): The air springs help isolate the cabin from road vibrations, contributing to the quiet and refined interior environment.
• Improved Fuel Efficiency: The system can lower the vehicle at higher speeds, reducing aerodynamic drag and potentially improving fuel economy.
• Customizable Ride: Some versions of the system allow drivers to select different ride modes, adjusting the suspension characteristics to suit their preferences or driving conditions.
• Towing Assistance: When adequately equipped, the air suspension can help maintain a level stance when towing, improving stability and control.

Key Components of the Lincoln Navigator Air Suspension

Let’s take a closer look at some of the crucial components that make up the Navigator air suspension system:

Air Springs

The Navigator uses two air springs located at the rear axle. These are robust rubber bladders that can withstand high pressures and repeated inflation and deflation cycles. They’re designed to:

• Support the vehicle’s weight
• Provide a cushioning effect for improved ride quality
• Adjust in volume to change the vehicle’s ride height

Air Compressor

The air compressor is a critical component of the system. In the Navigator:

• It’s a single-cylinder, electrically driven unit
• It’s powered by a solid-state relay controlled by the air suspension module
• The compressor is not interchangeable with those used in four-wheel air suspension systems
• It includes an integrated vent solenoid for releasing air from the system

Air Dryer

Connected to the compressor outlet, the air dryer plays a crucial role in system longevity:

• It contains silica gel, a desiccant that absorbs moisture from the compressed air
• This prevents water from entering the system, which could cause corrosion or freezing issues
• The dryer is replaceable and should be changed if an air spring fails or the compressor is replaced

Solenoid Valves

Each air spring has a solenoid valve:

• These electrically operated valves control the flow of air into and out of the air springs
• The air suspension module controls them
• The valves allow for precise control of air pressure in each spring, enabling the system to make fine adjustments to vehicle height and attitude

Height Sensors

The Navigator uses two ride height sensors mounted on the rear axle:

• These sensors provide real-time data on the vehicle’s ride height
• They output a voltage between 0.5 and 4.5 volts, with voltage decreasing as the vehicle rises
• This data is crucial for the system to make accurate adjustments

Air Suspension Control Module

This is the central processing unit of the air suspension system:

• It receives inputs from various sensors, including ride height, vehicle speed, and steering angle
• Based on these inputs, it controls the operation of the compressor and solenoid valves
• It also manages diagnostic functions and communicates with other vehicle systems via the CAN bus network

Air Lines

These are the pathways for compressed air within the system:

• They connect the compressor to the air springs via the solenoid valves
• In the Navigator system, there are two main air lines
• These lines are designed to withstand high pressures and cannot be spliced or repaired if damaged – they must be replaced as a unit

Maintenance and Common Issues

While the air suspension system in the Lincoln Navigator is durable, like any complex system, it can experience issues over time. You should always take your vehicle to a Lincoln dealership for maintenance and service where certified Lincoln technicians can diagnose and repair any issues. Here are some maintenance considerations and common problems:

Maintenance:

• Regular Inspections: Visually inspect air springs for any signs of damage or leaks.
• Air Dryer Replacement: Consider replacing the air dryer every 4-6 years or if any major component of the system fails.
• Compressor Care: Ensure the compressor intake is clean and unobstructed.
• System Calibration: Periodically, you may need to recolibrate the system using a specialized scan tool to ensure accurate ride height.

Common Issues:

• Air Leaks: Over time, air springs or lines may develop leaks, causing the system to run more frequently.
• Compressor Failure: The compressor can wear out, especially if it’s running more often due to leaks.
• Sensor Failures: Height sensors can fail, leading to incorrect ride height adjustments.
• Control Module Issues: Electronic faults in the control module can cause system malfunctions.
• Moisture Damage: If the air dryer fails, moisture can enter the system, potentially causing damage to various components.

Lincoln Navigator SUV: A Reputation for Excellence

The air suspension system in the Lincoln Navigator is a prime example of how advanced technology can significantly enhance the driving experience of a luxury SUV. Providing adjustable ride height, improved comfort, and superior handling characteristics contributes considerably to the Navigator reputation for excellence.

While the system’s complexity can lead to higher maintenance costs, many owners find that ride quality and versatility benefits outweigh these considerations. As automotive technology advances, we expect to see even more sophisticated air suspension systems in future Lincoln models, further refining the balance between comfort, performance, and luxury.