Overdrive Magazine | Trucking Business News & Owner Operator Info
Issue link: http://read.dmtmag.com/i/769491
January 2017 | Overdrive | 31 driver is able to identify other problems when it's not 'driving like a truck.' " Comprehensive balancing not only en- ables the identification of wheel-related problems, but also helps prevent many problems, Forney says. "Balancing wheel assemblies reduc- es the damage that vibration causes on lights, bearings, U-joints and other suspension parts, resulting in reduced downtime and lower maintenance costs," he says. Centramatic's Bob Jessee agrees. "When you eliminate controllable vibra- tions all day every day, all parts that are vulnerable to vibrations – bearings, tie rod ends, ball joints, kingpins, onboard computers and electronics and gauges – will last longer," he says. Eggen says his preference to balance was based on his understanding that a truck that just rolled off the assem- bly line wasn't perfectly balanced and road-ready. Forney explains it this way: "When a tire is mounted on a wheel, and the wheel assembly is mounted on a truck, it now has an out-of-balance – known as the heavy spot – which is different than the heavy spot of just the tire or wheel alone." Others believe that such reasoning isn't as valid as it once was because the materials in truck tires and the engi- neering behind their designs have come a long way, as has the use of aluminum wheels. That's changed the dynamic of the tire and wheel assembly, says Delvin Webb, U.S. customer engineering sup- port manager for Michelin Truck Tires. "In most instances, commercial truck tires do not need to be balanced," he says. "With tighter uniformity standards in manufacturing, tires, wheels, hubs and drums do not need routine balancing." While it is customary to check the balance of the tire and wheel assembly when a driver makes a ride complaint, the vibrations usually come through the steering column or the seat, often making it difficult to pinpoint the problem. "Michelin recommends that before removing the tire and wheel assembly from the vehicle, the radial and lateral runout be checked by a professional technician," Webb says. "Bent wheels, improper mounting or flat-spotting can cause excessive runout. If balancing is still required, a simple static balance with bubble balancer or a wall-mounted axle bearing and hub-type gravity balancer should be sufficient." Many of Goodyear's truck tires "have a red dot marking applied to the sidewall to indicate the high point of radial runout," says Mike Manges, manager of the company's commercial and off-high- way tire communications. Radial runout means the radius is not uniform from the center to any point on the tire's rim. "The red dot should be used for the initial match-mounting of tire/wheel assemblies, as well as for installation on the vehicle," according to Goodyear's recommended procedures, Manges says. He also notes the Technology and Maintenance Council's Recommended Practices Manual is a good resource for balancing tires. Jessee says the idea of not balancing tires is a persistent myth that began when most trucks had Dayton or spoke-style wheels outfitted with bias ply tires. "Back then, it was believed to be a waste of time and resources to balance truck tires," he says. "This is the gen- eration that started the phrase 'It rides like a truck.' By the time the Budd wheel evolved, and then when radial tires for trucks became most common, the myth and the phrase had stuck." Jessee says "visible and controllable forces" that cause premature tire wear include misalignment, worn suspen- sion parts, worn or incorrectly torqued bearings, incorrectly mounted tires and incorrect air pressure. Imbalance also is controllable, but because it's invisible, it's often ignored. "All the forces, visible and invisible, must be neutralized to get maximum life out of tires," he says. Another aspect of balancing is wheth- er it improves fuel efficiency. Forney says more fleets are looking at tire balancing to improve not only tire life but also fuel efficiency by up to 2 percent. "To do so, they are finding more time-efficient methods or are spin-bal- ancing despite the time factor," he says. Before Equal Flexx was introduced 25 Running imbalanced drive tires can produce shaking that transfers to the cab. Yes, with an onboard hub-mounted system 25% Yes, with traditional spin balancing 41% Yes, with a drop-in/internal tire product 17% No 13% Other 4% Owner-operators: Do you have your tires balanced? OverdriveOnline.com poll, 936 respondents