Vehicle alignment settings serve a variety of functions in vehicle operation. They affect handling, steerability, stability, performance and safety, among other things. When a vehicle is in total alignment, all wheels “agree” on one direction so there are no lateral forces to counteract.
Research has shown that total vehicle alignment maintenance and inspection programs can pay dividends in extended tire wear for increased tire mileage, enhanced fuel economy, decreased component wear, greater uptime, improved driver comfort and safer vehicles. Nevertheless, industry experts estimate that 70 to 80 percent of Class 8 trucks on the road today have alignment problems.
“The vehicle is a composite with the chassis as the foundation,” explains Dutch Johnson, Josam Products’ training manager. “The foundation must be square and solid to support the dynamics of the complete structure.”
Based in Orlando, FL, Josam Products is the North American operation of Josam, the world’s leading manufacturer of heavy duty vehicle frame and axle alignment equipment.
The chassis includes every wheel, axle, suspension component and frame member, he says, and all should be aligned in relation to one another as a whole.”
Total alignment is a correction of the entire vehicle geometry instead of only one wheel or one axle independently, adds Nick McCullough, president, RAV America, Texarkana, TX, a business involved in the sales and service of heavy duty wheel service equipment, with a special focus on wheel alignment. The complete rectangle is considered, with the alignment performed in stages, usually one axle at a time.
A vehicle not in proper alignment “is a recipe for a maintenance manager’s nightmare,” asserts Greg Brock, Hunter Engineering Company’s heavy duty equipment training instructor. “Misalignment affects every aspect of operating costs per mile.”
Hunter Engineering, headquartered in St. Louis, MO, is a leading manufacturer of automotive service equipment, including alignment systems, wheel and tire service, brake service and inspection lane equipment.
“Often times, the difference between a ‘good’ truck and a ‘bad’ truck is simply one that handles well due to proper alignment, Josam Products’ Johnson states.
With improper vehicle alignment, the two largest maintenance expenditures - tires and fuel - suffer the most, says Brock. Misaligned axles and tires cause the tires to be scrubbed across the pavement, increasing rolling resistance, which directly impacts fuel consumption.
Such unnecessary lateral forces not only require more horsepower to move the same load, they also significantly reduce tire mileage, resulting in more frequent tire replacement,” says Brian M. Lukavich, parts and service programs manager, TravelCenters of America Truck Service and Petro Lube. Based in Westlake, OH, TravelCenters of America (TA) is a leading travel center business in 41 states and Canada, operating under the TravelCenters of America and Petro brands.
“If the tires are not pointing strait down the road, they will wear, or basically scrub along the road, causing less life for that tire,” he says. “I have seen tires with more than 10/32nds on one side and down to the cords on the other. Tires like those did not provide the proper return on investment to the fleet, and in most cases, are no longer an acceptable tire casing, causing the fleet less return when a casing credit is not available for them.”
“Experience and studies have proven that 70 percent of steer tire wear problems originate from the drive axles,” says Mike Beckett, president, of M.D. Alignment Services, Des Moines, IA, a company that offers alignment equipment for heavy trucks and trailers, as well as alignment training and consulting. He is the author of the book, Truck Wheel Alignment: A Common Man’s Guide, which provides basic guidance to solving all the major aspects of vehicle alignment and tire wear.
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