Here’s a great information about oscillating axle system
When using an oscillating axle system, the two sides of the axle can pivot in response to flooring surface on which they operate so that all wheels remain on the ground when the equipment is on the move, but lock into place when the boom is elevated, to ensure stability. This means greater safety when operating the boom, and a smoother ride and greater operator control (and confidence) when moving the equipment. The system also reduces the risk that the AWP will get stuck, because the wheels are always in contact with the ground so they can always be used to propel the equipment over the terrain.
Not all AWPs are fitted with the feature, as it requires a more complex mechanical system with more hydraulics and more electronics. Nonetheless over the years, oscillating axles have been offered as a standard feature on more and more AWPs produced by most of the leading manufacturers.
Normally, if the platform is in the air, the oscillating axle feature is disabled. The reason is that the stability is reduced. Indeed, if ever there is any sort of equipment malfunction, one of the checks that we at Manlift run is to ensure that the oscillating axle system does automatically lock during operation and is only functional when the platform is in transport position.
However, an interesting variation is the active oscillating axle offer by Genie. This system has the additional benefit of being able to drive the AWP even when the boom is elevated and while the axle is oscillating. This brings with it improved maneuverability over slightly uneven ground even when the access platform is elevated.
The various usages and benefits of oscillating axle were discussed during IPAF trainings to give operators a full understanding of how this important feature works and how to use it to best advantage.