What is the function of a trailer jack?

The function of a trailer jack is primarily to support the trailer when it is not connected to the truck, which allows for stability and safety during loading, unloading, or maintenance activities. When a trailer is uncoupled from a truck, the trailer jack helps to prevent it from tipping over or rolling away, ensuring that it remains safely in place.

While there are other functions associated with trailer jacks, such as assisting during coupling or occasionally elevating a trailer for loading purposes, the key purpose is to provide reliable support when the trailer is detached. This makes it an essential tool for anyone using combination vehicles, as it adds safety and convenience during operations involving trailers.