The term BAR ON A TRUCK is a crossword solution which can be broken down into two words: 'AXLE' (4 letters) and 'BAR'. An AXLE is a shaft that connects two wheels of a vehicle, such as a truck, and the BAR is a metal rod that is attached to the AXLE. This BAR is used to support the weight of the vehicle and to keep the wheels in alignment. The BAR on a truck is an important part of the vehicle's suspension system and helps to ensure a smooth ride.