One of the secrets to maximizing tire life involves keeping round objects on the straight and narrow. Unless everything is properly balanced and aligned, the resulting wobbles, twists and drags eat away at treads and driving experiences alike.
Indeed, truck drivers are usually the first people to notice balance-related issues. The vibrations from imbalanced steer tires tend to telegraph their way through steering columns, while vibrating seats can point to problems with drive tires. Even if such issues are masked by well-maintained suspension components, it’s hard to overlook the shaky reflections in West Coast mirrors.
Chris Schutt, technical training specialist at Bee Line Company, a supplier of balancing and alignment equipment, likens the experience to driving down a washboard road all day long. “The driver is kind of connected to the tires through all the steering components,” he says.
It’s one of the reasons that Bee Line president Lee McLaughlin says tire balancing plays a role in driver retention. The more drivable the truck, the more comfortable the job.
“If [fleets are] balancing the tires and they also have that maintenance program in place, they’re going to head off problems before they start,” Schutt adds, referring to the unwanted edge wear, feathering and cupping that can manifest itself on tire treads.
“There’s a lot of forces pushing on that tire.”
– Colin Rafferty, Kal Tire
“It takes a while for that cupping to progress,” adds Colin Rafferty, senior corporate account manager with Kal Tire, referring to the high and low points that can emerge, especially on steer tires. “By the time you see the wear problem, it’s too late to do anything about it.” Replacements and roadside assistance calls await.
Yes, the balancing comes at a cost. But he suggests that’s a small price to pay when maximizing the service life of steer tires worth $700 to $900. And while the torque applied to a drive axle will scrub tires down to an even circle, the shortened tire life is hardly welcome news there.
Even the tires from Tier One suppliers – options that are more likely to run true than bargain-priced offerings — should be properly balanced when they’re installed.
“You look at the weight of a tire and wheel together, it’s a lot of mass that’s turning as it goes down the highway,” Rafferty explains. “There’s a lot of forces pushing on that tire.”
He emphasizes the value of dynamic mechanical balancing, which involves loading a tire and wheel assembly onto a balancing machine, spinning it up, and attaching weights to ensure everything runs true.
The benefit of an on-vehicle balancing is that variations in the hub, drum and wheel are all addressed, McLaughlin says, noting that the Technology and Maintenance Council (TMC) of the American Trucking Associations refers to it as the gold standard.
And the key is to complete the work whenever new tires are installed.
“We know the tire and wheel assembly is true and it’s going to run down the road properly,” Rafferty says, referring to the result. Then it’s a matter of revisiting the process if something feels wrong or unwanted wear patterns emerge. “Unless the weights come off, it’s not going to go out of balance.”
“We’ve even heard of people putting golf balls in the tires.”
– Lee McLaughlin, Bee Line
Some alternatives such as beads and liquids inserted into the tires can be problematic, though. Internal balancing materials with a high moisture content can affect tire warranties if they harm inner liners or casing plies, Michelin notes in its bulletins.
Beads are less popular than they were eight or nine years ago, as people shy away from adding things that could damage the inside of the tire, McLaughlin says.
Then again, some people continue to embrace such options – as well as some decidedly unusual alternatives.
“We’ve even heard of people putting golf balls in the tires,” he says.
No matter how tires are mounted on their respective wheels, though, they all need to be pointing in the same direction, and that straight path can be challenged by factors such as worn or settling suspension components.
Misaligned toe angles can lead to irregular wear on both steer tires, leaving a feathered scuff across the tire’s crown. Too much toe in will scrub both tires from the outside in, while too much toe out will scrub the tire’s tread from the inside out. And mirrors which show a better view of one side of a trailer than another are clearly a sign that things need to be realigned.
Adjusting the toe angles on the steer axle will help keep the truck from wandering down the road.
Even little variations can mean a lot. Steer tires misaligned by just 1/8 inch will drag a tire sideways by the equivalent of 7.5 feet per kilometer of travel. Push the drive axles out by 1/16 inch and they are dragged 13.5 feet per kilometer. “It’s exaggerated more on the drive tires because of the wheelbase of the truck,” Rafferty explains.
There are plenty of underlying forces at play. Cupping and flat spots can be linked to factors as diverse as loose wheel bearings and worn tie rod ends. The advantage of scheduling alignment checks is that mechanics will put their hands on such components, to ensure everything is working as designed.
“I think people have a tendency to understand [tire] balance better,” Rafferty adds. “I don’t think there’s as much knowledge out there when it comes to alignment, or the understanding that it’s a regular maintenance issue – that suspensions are going to wear.”
Alignment problems can also be more widespread than some people think. Quoting statistics from Hunter Alignment, Rafferty says 80% of the trucks on the road have misaligned steer tires, while another 70% have misaligned drive tires.
Better fuel economy
The unwanted outcomes aren’t limited to premature tire wear, either. Properly aligned tires also support better fuel economy. “Having all the tires pointed straight down the road is going to help that wheel run true and reduce the amount of energy,” Rafferty says, adding that alignment issues can reduce fuel economy by 2%.
Then there are the issues including frequent tire changes, road calls linked to failed tires, and the outright fatigue that emerges as drivers fight with their steering wheels to keep everything pointed in the right direction.
“To keep the truck between the lines, the driver is going to turn the steering wheel one way or the other,” Rafferty says. “The same would hold true if the trailer is misaligned because the trailer will dogtrack … the correction is always there at the driver’s end.”
McLaughlin notes that Bee Line prefers to align everything to the center of the frame, to eliminate unwanted dogtracking. Tighter specifications for toe, camber and caster can also make a difference, he adds, noting that OEM spec’s can range between 0 and 3/32 inches.
“There are imperfections with any alignment equipment, so zero might be a negative toe if you factor in the imperfections of the alignment,” he says.
For those who are installing the equipment in their own shops, McLaughlin stresses the value of equipment that can be calibrated on site within minutes. And Schutt points to small fixtures that can be maintained in house rather than requiring on-site support.
There’s even a case to be made for alignment checks as soon as a new truck arrives for its pre-delivery inspection. Suspension components can settle in place during transport.
From there, Rafferty recommends re-checking that alignment every time a new set of steer tires is installed. There’s simply no avoiding the issues that can emerge as trucks bump and weave their way through potholes and over bumps.
“It’s not a question of if [alignments will be sacrificed]” Rafferty says. They will. They absolutely will.”