Suspension system service: Knowledge is power
New heavy-duty suspension systems also are designed to require minimal service, but it’s still imperative for aftermarket businesses to understand maintenance requirements.
Just because a system is built to last doesn’t mean it’s indestructible.
“Hendrickson tries within the design of its suspension to minimize the maintenance that’s required,” Adkins says. “So while there are no physical actions necessary, we ask customers to look for tell-tale signs of things going badly during visual inspections.”
Simmons says drivers should visually check suspensions during daily inspections. Full-service suspension inspections also are recommended once a year, he says. Nolan says repair facilities should offer these inspections to customers as part of preventive maintenance stops.
A suspension inspection should begin with a visible inspection of the tractor and trailer’s balance, says David Washbish, president at Lexington and Louisville Auto Spring. If level, technicians should then check the equipment’s height before going below to check system components.
Washbish says the suspension and leaf springs should be inspected for cracks and wear, while air springs should be monitored for air loss. Shock absorbers also should be checked for leaks, Adkins says, and bushings, bolts, fasteners and slider pins should be in proper working order.
Nolan says some minor cracks can be welded back into safe operating condition, and technicians should determine if that’s possible as soon as cracks are discovered.
In cases where a component must be replaced, Adkins advises to check the wear on corresponding parts before replacing every unit.
“Sometimes you won’t need to replace everything,” he says, but adds that some components — pivot bushings, for example — will work best if all are replaced at once. “If you just change one and not the other, the wear rate may change across the vehicle.”