Suspensions for trailers and semi-trailers: which components to check

The suspensions for trailers and semi-trailers are subjected to loads, vibrations and stresses on a daily basis. Over time, these conditions can affect the efficiency of different components. For this reason, periodic checks and correct maintenance are important to identify any anomalies and verify the behavior of the vehicle.

Shock absorbers, air springs, bushings and connection points work within the same suspension system. Consequently, the inspection should not focus on just one element, but consider the conditions of the entire system.

So let's see what the main ones are suspension components of trailers and semi-trailers to be checked and what signals may suggest the need for a more in-depth review.

Suspensions for trailers and semi-trailers: checking the shock absorbers

The shock absorbers for trailers and semi-trailers they have the task of controlling the oscillations generated by the movement of the suspensions and by irregularities in the road.

With progressive use, their performance may decrease. During checks it is therefore useful to check for any leaks, damage, anomalies in the connections or other signs that may indicate a reduction in efficiency.

A shock absorber does not necessarily have to have an obvious break due to having lost some of its damping capacity. For this reason, the evaluation of the state of the component must be inserted within the normal semi-trailer suspension maintenance.

Air springs in air suspension for semi-trailers

In the systems of pneumatic suspension for semi-trailers, air springs play a central role in supporting the load and allowing the suspension to function properly.

The spring surface can be checked for cracks, abrasions, deformations or other signs of deterioration. It is also important to check for any pressure losses and observe whether the vehicle maintains its stability correctly.

An anomaly does not always depend directly on the air spring: connections, valves and other elements of the pneumatic circuit can also influence its operation.

Bushes and fixing points

Bushings, supports and connection points are also among the elements to consider during the checking the suspension of a trailer or semi-trailer.

Excessive play, wear or deterioration can change the way suspension components work together.

During the inspection it is therefore advisable to check the state of the connections and make sure that there are no visible anomalies or unexpected movements.

Tires: a useful indicator of the state of the suspension

Observing the tires can also provide useful information.

And’irregular tire wear it can be associated with different causes and does not automatically indicate a problem with the shock absorbers. However, in the presence of anomalies, it is advisable to also check the suspension system, the set-up and the other components involved.

In fact, tires and suspensions work within the same dynamic system and the behavior of one element can provide useful information on the state of the others.

What signs can indicate a suspension problem?

In addition to the inspection of individual components, some behaviors may suggest the need for a more in-depth check of the components semi-trailer suspension.

Abnormal oscillations, noise, non-uniform ride, vibration or behavior that differs from normal operating conditions should not be automatically attributed to a single component.

A check of the entire system allows the origin of the anomaly to be identified more precisely.

Why periodically check the suspensions of trailers and semi-trailers

Trailers and semi-trailers can operate for long distances and under different load conditions. There is therefore no single condition of use valid for each vehicle.

Enter the suspension control within periodic maintenance it allows you to check the state of the components and intervene when necessary, before the wear of an element can influence the overall behavior of the system.

Suspensions for industrial vehicles: the Way Assauto experience

Knowing the functioning of the different components is essential to carry out correct checks and identify the most suitable solution for the specific application.

Way Assauto develops solutions for the world of industrial vehicle suspensions, with applications dedicated to trucks, trailers and semi-trailers.

Shock absorbers and air springs are part of a system in which each component contributes to the correct behavior of the suspension: for this reason maintenance, control and correct identification of the spare part represent fundamental aspects during the entire use cycle of the vehicle.