In Focus: Pre-service inspections

Many fleets have inspection lanes in their shops intended to incorporate production-line efficiency into routine maintenance checks. While well-trained technicians often can eyeball the chassis, feel for problems and successfully uncover burgeoning defects, high-tech equipment is becoming increasingly common. Vendors say their products can make the inspection lane a more effective way to cut maintenance and other costs.

“It’s a brave new world in the maintenance shop,” says James Soucie, market development manager of Vehicle Inspection Systems Inc. “What you did five years ago, you have to change.” VIS makes a performance-based roller brake tester, as well as the VIS-Check dynamic undercarriage inspection system that “inspects as if you are driving, mirroring what actually happens on the road,” Soucie says.

The system is designed to shake wheels back and forth and measure the resistance in such a precise way that it yields a diagnosis. “You immediately find worn torque arm bushings, broken springs, a suspension at an angle to the chassis, and the like,” Soucie says. “By the time you see the wear on a tire, the suspension is often ruined.” Other worn or damaged parts the system discovers include kingpins, tie rod ends, shock bushings and loose wheel bearings, he says. The system is designed to allow such parts to be inspected dynamically in 15 minutes, while a manual inspection would subject them only to a static look and could take 21/2 hours.

VIS supplies training with the equipment. The goal, says Soucie, is to prevent both under-repair and over-repair, creating “a factual business decision” that reduces the breakdowns between inspections – keeping drivers on the road and happy – and also cuts repair costs.
Hunter Engineering Co. produces both a heavy-duty brake tester/scale unit designed to test brakes the way they function, and a side-slip tester built to uncover alignment issues as well as loose components. “It can tell you you’re driving down the road with your tires scuffing and pulling to one side,” says Mitch Weller, the company’s product manager. “Once these situations get beyond normal scuff rates, they really need to be checked and the problem rectified.”

Such trouble more often is discovered and repaired on tractors than on trailers, Weller says, because most fleet maintenance managers and technicians understand tractor alignment problems – but leave the trailer alone. However, a dog-legged trailer can create just as much steer tire wear as a misaligned tractor suspension. Such problems not only contribute to high tire costs, but also waste gobs of fuel.

“One fleet put a side-slip tester in one of their trailer shops and saved several hundred thousand dollars in just tires, not counting wasted fuel,” Weller says. The side-slip tester does its job so well, he says, that many fleets can use it to determine what pieces of equipment need time-consuming visits to full alignment racks, saving time in the inspection lane.

MAHA USA makes both a brake tester and test lane shaker plates designed to find worn kingpins, tie rod ends and any other loose suspension component. MAHA also provides a smog meter, which is helpful not only when older equipment encounters roadside smog checks that could yield expensive fines and downtime, but also for fleets to determine how clean the engine is running for better fuel economy. “You can maintain the engine better and will know when something is going wrong,” says Udo Vespa, the company’s technical manager.

Josam Products’ AM800:K Play Detectors also are designed to find worn parts. “One technician with a pry bar can only exert limited leverage,” says Norman “Dutch” Johnson, sales and technical support manager. Josam’s play detectors are made to exert several tons of force on each wheel end to approximate the dynamics of the vehicle as it accelerates, brakes and corners on the road. “The inspector can observe the movement of the chassis parts while controlling the movement of the component with a handheld control and built-in halogen light,” Johnson says. With play detectors installed over a pit, low-clearance vehicles, trailers and buses can be inspected thoroughly, he says.