A trailer's axle group and suspension are the sole interface between the load and the road. When this system is healthy its presence goes unnoticed; when it wears out, the bill is not paid by itself, but by the tyres, fuel consumption and load damage.
Points to Check Regularly
- Air bags: Surface cracks, chafe marks and air leaks; a burst air bag is among the most common causes of a roadside breakdown
- Shock absorbers: Oil leaks and ineffective damping; a dead shock absorber leaves an irregular wear pattern on the tyre
- Bushings and connection eyes: As play grows, axle geometry shifts during travel
- Level valve: Incorrect adjustment disrupts body height and load sharing between axles
- Axle alignment: The classic source of pulling, one-sided tyre wear and increased fuel consumption
The Tyre Is the Most Honest Witness
Most suspension problems first show up on the tyre surface: a saw-tooth pattern points to a dead shock absorber, one-shoulder wear to an alignment fault, irregular local wear to a worn bushing. Examining the old tyre's wear pattern at replacement time is a free suspension diagnosis.
Axle alignment must be measured loaded and on level ground, according to the manufacturer's procedure. A correctly aligned axle group travels silently; it is the fleet's job to preserve that silence with regular checks.