What is the main characteristic of a solid axle suspension system?

A solid axle suspension system is characterized by a single housing that connects both wheels as a unit. This design allows for both wheels to move together as one piece, which provides a strong and rigid suspension setup. This configuration supports the vehicle's weight effectively and maintains a consistent axle alignment under various driving conditions.

Unlike an independent suspension, where each wheel can articulate independently, the solid axle connects both wheels, which can enhance durability and simplify the design, making it a common choice in heavy-duty or off-road vehicles. The solid axle allows for better load distribution across both wheels and can improve traction in rugged terrains since both tires share the same drive line and are less likely to experience differential loading.

The other options describe features more typical of different suspension systems. Independent wheels are characteristic of independent suspension systems, where each wheel can react separately to road conditions. Multiple pivot points are generally associated with advanced suspension systems that aim for improved flexibility and handling. Adjustable ride height mechanisms are often found in air or adaptive suspension systems, allowing for changes in the vehicle's stance.