TORONTO, Ont. – Most wheel separations occur in the winter, when trucks are regularly travelling through areas of vastly different temperatures.
“With big swings in the temperature, we see more loose wheels starting in November, especially on trucks running north,” explains Brad Hawke, owner of Oakville, Ont.-based Fleet Tire Supplies. Wheels experience heat build-up when they’re in operation, and can expand and contract when going from hot temperatures to the cold of being parked overnight in, say, Thunder Bay. With the shrinkage of the metals, “We get a drop in torque and then you can run into problems with wheels coming loose,” Hawke says.
Almost all wheel-off incidents are preventable, according to Sgt. Cam Woolley of the Ontario Provincial Police. Here are five ways drivers and wheel installers can minimize the risk of losing their wheels:
Ensure wheels are fastened properly
Check the studs to ensure the threads are in good shape before tightening, suggests Hawke. When a stud is overtorqued, the threads stretch, compromising the integrity of the stud.
“You can’t guess torque by looking at the fasteners,” points out Sgt. Woolley.
Hawke says wheel installers should regularly calibrate their torque wrenches to ensure they are properly torquing wheels.
“Torque wrenches are fine measuring devices,” Hawke points out, adding they can lose their accuracy through regular use and getting banged around or dropped. He suggests having torque wrenches calibrated every six months – or once a year, at least.
Always re-torque the wheels
After an initial wheel installation, the wheels should be re-torqued several times to ensure they’re properly installed, wheel experts advise.
“When you’re installing hub-pilot wheels, you need to re-torque them three times,” says Hawke.
He recommends first re-torquing them at 160 kms, then again during the first week of service and a third time during regularly-scheduled maintenance. Sgt. Woolley says many wheel-off incidents can be traced back to a failure to re-torque a new wheel.
“We’re finding with re-torque -0 a lot of people just don’t do it,” he says. “They get the wheel on in Toronto and then they’re going to Thunder Bay. Well, the tire guy doesn’t follow them and re-torque it along the way.”
Clean components during service
Another common mistake in the shop is that wheel installers slap together a wheel assembly without taking the time to properly prepare the components for re-assembly.
Hawke says all components must be thoroughly cleaned before being put back onto the truck.
“You have to get rid of corrosion, road dirt and debris,” he warns. “The cleaner the wheel assembly is before it goes back together, the better the chance of success.”
Maintenance managers should also take this opportunity to examine parts for wear or defects.
Watch for warning signs
Drivers must realize they will be held accountable for wheel separations, notes Sgt. Woolley. Therefore, they should regularly check their wheels for signs warning of potential problems.
“There’s no real magic trick to this, drivers have to have the knowledge to know what they are looking for,” points out Rolf VanderZwaag, manager of maintenance and technical issues with the Ontario Trucking Association. “They need to be aware of the kind of repair work that has been done on their vehicles and they need to pay attention to signs of trouble, like when it’s noisy and when there are the classic rust streaks. Oil leaks from the wheel seals usually indicate a precursor to bearing failures. If there’s anything out of the ordinary, they need to check in with someone that can do a more detailed inspection.”
VanderZwaag points out an observable problem can quickly become a full-blown wheel detachment. “Whatever is compromised in that assembly can go to a full wheel-off in the matter of a couple of miles,” he points out.
Implement a proper maintenance program
It’s critical to have a good wheel maintenance program in place, insists Hawke.
“I think the progressive, well-managed fleets are very proactive in it, but I think some of the small carriers don’t have a large enough staff to stay on top of these things and they sort of neglect it a bit,” he adds.
Woolley says fleets need to have a wheel safety program that involves training drivers how to identify problems. While few O/Os install their own wheels, Hawke reminds carriers they’re accountable for the their O/Os’ equipment. “Fleets that have O/Os working for them should make sure they are following a maintenance program.”