Swing Axle Suspension: History, Function & Modern Applications

Swing-axle is a type of vehicle suspension in which the axle itself is allowed to pivot under the car. This design was popular on smaller automobiles in the 1950s and 1960s, and while today it is considered antiquated, it is still commonly used on trailers, especially small ones.

When the vehicle experiences a bump in the road, the rear axle pivots together with the wheels. This creates a situation in which the side of the vehicle that is experiencing the bump moves further downward while the opposite side moves upward, causing a sideways tilt. This side-to-side motion can be uncomfortable and unstable for passengers.

A variation on the swing-axle design is the single swing axle, which only allows one side of the axle to pivot. This provides a slight improvement in stability, but the disadvantages are similar to those of a traditional swing axle.