Final answer:
Wheel tramp can be caused by an overload condition, an under-inflated tire, a broken spring pack, or static unbalance of a wheel assembly. An empty freight truck trailer is likely to bounce more compared to a heavily loaded one due to insufficient damping by the springs.
Step-by-step explanation:
Wheel tramp, also known as wheel hop or axle tramp, is a vibration or hopping of the wheel of a vehicle. This can often be observed in vehicles carrying heavy loads or when accelerating rapidly. Wheel tramp can be caused by several issues:
- An overload condition, where the weight of the load exceeds the suspension's capacity, leading to inadequate dampening and control.
- An under-inflated tire can also contribute to wheel tramp due to less tire contact and ineffective shock absorption.
- A broken spring pack in the suspension system, which can disrupt the balance and cause the wheel to bounce uncontrollably.
- Static unbalance of a wheel assembly results in unequal weight distribution around the wheel's circumference, leading to repetitive bouncing.
When you notice a freight truck's trailer bouncing up and down slowly, it is more likely that the trailer is nearly empty. A heavily loaded trailer tends to have less bounce because the kinetic energy of the wagons is more effectively absorbed by the load, and the potential energy stored in the springs is more significantly dampened due to the weight. Conversely, an empty trailer lacks sufficient weight to compress the springs and dampen the movement, leading to a more pronounced and slower bounce.