A flurry of high-profile wheel separations in Ontario over the past five months, including two that resulted in fatalities, has placed the issue of wheel safety back under the public spotlight and led to heightened enforcement activities.

There have been 27 reported wheel separations in Ontario this year to date through March 3, putting the industry on pace to record a startling 157 incidents, which would be the most since 1998. Wheel-offs were down in 2015, to 127 reported incidents compared to 148 in 2014 and 147 in 2013. However, each of the last three years was markedly higher than the 97 reported in 2012 and every other year dating back to 1998, during which no more than 99 wheel separations were reported in any given year.

Still, Chris Davies, strategic program and policy advisor, regional operations branch with the MTO, said there are some explanations for the uptick. Firstly, separations occur more often during the winter months, when cold temperatures cause fasteners to expand and contract more frequently. Also, snow and ice accumulation on the wheels can cause some drivers to overlook warning signs during their pre-trip inspections. So there’s a chance the high monthly numbers reported early this year will level out as warm weather arrives.

And as for the three-year spike seen from 2013-2015 compared to the previous 15 years, Davies said it could be in part due to the fact MTO has appealed to its enforcement partners in recent years to do a better job of reporting wheel separations.

“We have strengthened up the reporting with our police partners,” Davies said in an interview with Truck News. “It looks like there has been a spike. But at the same time, in our refresher training for our officers and with our police partners, we enhanced the reporting and sure enough, we got more reports.”

Whatever the reason for the increase in reported wheel separations in recent years, the MTO is taking the issue seriously. On Dec. 22 it launched Operation Wheel Check and since then it has inspected more than 29,400 wheel assemblies and placed 20 vehicles out-of-service for wheel-related defects. The program places a “laser focus” on wheel safety, Davies explained, and allows zero tolerance for trucks and trailers found to have any wheel-related issues.

“When wheel defects are found, the vehicle is immediately taken off the road and prohibited from operating until it is brought into compliance,” he explained. 

In addition to the 20 vehicles placed out-of-service, another 110 have been held by MTO until repaired.

According to MTO data, 90% of wheel separations are hub and fastener related. Avoiding wheel-offs begins with
a proper wheel installation, which can prevent nearly all separations.

“The engineering of the components is adequate,” said Rolf VanderZwaag, manager, maintenance and technical issues with the Ontario Trucking Association (OTA). “There is no inherent weakness in any of this, so that leads to, if you put them on right, everything will perform as expected.”

VanderZwaag helped Ontario develop its mandatory Commercial Vehicle Wheel Service training program, which was introduced in the mid-1990s following another series of high-profile and tragic wheel-offs. Today, Ontario is the only province that requires wheel installers to become certified, though the program is widely used in other provinces as well.

“We’ve trained thousands and thousands of people,” VanderZwaag said.

But Dave McDonald, commercial sales manager with Bridgestone Commercial Solutions, noted not all technicians have received sufficient training on wheel installations from their technical schools. The biggest problem he sees in the field is the installation of wheels without lubrication.

“A lot of people don’t understand that the torque values in a hub-piloted wheel system are lubricated values,” McDonald explained. “If you don’t use the proper lubrication in combination with a calibrated torque wrench…the torque you put on is not going to develop the necessary clamping force and the wheels can come loose. Just because the torque wrench says 475 lb.-ft. doesn’t mean you have the right amount of clamping force. People believe it’s the torque that holds the wheel on the vehicle, but it’s not. It’s the clamping force.”

McDonald said wheel installers need to take a complete systems approach to their work, noting how each step in the process affects other components within the system. This means properly cleaning fasteners and mating surfaces and inspecting the components for signs of wear before they’re re-installed. It’s a job that can’t be rushed, he stressed.

“If the job takes 45 minutes, it takes 45 minutes,” he said. “I don’t care if dispatch is screaming for the truck or operations are screaming for the truck, you have to do all the steps. It’s a complete system.”

Jim Wagner, sales manager with Bast Tire and Auto Service in Waterloo, Ont., added installers need to inspect studs carefully between installations – especially in applications where the wheels are frequently removed.

“It’s really hard for a person to be able to tell whether the stud has been stretched to the point where you have to replace it,” he acknowledged. “I deal a lot with the waste industry and because they have so many flats on some of these trucks, they may have the wheel off and on one truck 12 times in a year. Every time you’re torquing that thing down, you’re stretching that stud and at some point in time your stud is going to become very weak.”

It’s also important to use quality fasteners, which will be more resistant to fatigue.

“If you want to save money in your maintenance budget, this is not the place where you want to save 20 cents on a cheap offshore nut,” McDonald said. “You want to make sure you’re using top quality fasteners and top quality wheel-end products.”

When a wheel has been removed from and re-installed onto a truck or trailer, operators are required to stop to have those wheels retorqued 100 kilometres into their trip. Torque stickers should be placed on the unit to remind drivers to have this done.

“All the joints, as you put them together, have what they call stack settling (between metal components),” Wagner explained. “Even if you torque it, let’s say there’s a little bit of dirt or oil or something between those stacks, as it moves and flexes and twists and so on, you may lose a bit of clamping force.”

Do most operators take the time to stop for a retorque after 100 kilometres? Opinions on that vary widely. Dale Holman, president of a small fleet called Tabcor Holdings and a certified wheel installer, pointed out retorquing has its limitations.

“Nobody gets their wheels retorqued unless they have a very strict company policy and they have four tire companies within a radius of their shop, where they can pull in and get retorqued,” he said. “And if I’m a guy doing the retorque, how do I know the first guy doesn’t have it torqued to 1,000 lb.-ft.? You can’t measure excessive torque without removing the nuts and then it starts the whole process all over again.”

McDonald agreed that, “The success or failure of the retorque is directly dependent on the original installation. If the original installation was done improperly or they didn’t use lubrication, you can retorque the thing until the cows come home. You’re going to get the right amount of torque but the wheel’s still going to be moving behind the nut because you don’t have the clamping force.”

Davies emphasized the importance of verifying the torque within 100 kms to ensure the installation was done correctly and the wheel is still secure. Fleets should have incentive to conduct rechecks, since they’re required to maintain a full and complete vehicle maintenance file, which includes the name of the technician who did not only the wheel installation, but also the retorque.

“With no paper trail,” McDonald said, “they don’t have any of that.”

If an issue exists with a wheel installation, drivers are the last line of defence before a potentially catastrophic separation occurs on the road. They should be conducting thorough pre-trip inspections and looking for telltale signs of movement, such as rust streaks.

“That’s a sign of metal rubbing on metal,” McDonald explained. “It’s just metal filings that splay out from the wheel through the centrifugal force of it driving down the road. Then, you get a little moisture in the air and the metal filings turn to rust and it turns into a rust streak. Anytime you get that type of thing emanating from the wheel nut, that’s a classic sign of an issue and you’re out of service right there.”

Wagner advised against placing caps over the studs, as they can conceal potential warning signs.

He also said drivers should give tires a good kick during their walk-around inspections to see if there’s any movement.

A loose wheel will often vibrate or sound different than a secure wheel when thumped.

“When you find one that is loose, the sound is totally different than what a tight one is,” he said.

Drivers should also look for cracks, especially around the wheel holes and on the face of the wheel. The driver’s role in preventing wheel separations cannot be overstated. In Ontario, wheel-offs constitute an absolute liability offense, meaning the vehicle owner is held responsible with no defence and will incur a fine of between $2,000 and $50,000.

Bridgestone’s McDonald said fleets need to impress upon their drivers the importance of regularly inspecting the wheels and also having issues addressed immediately.

“If the mechanic or the wheel installer makes a mistake and you get a little bit of movement on the wheel, the pre-trip inspection is where the driver is going to see that movement,” McDonald said. “I don’t think drivers understand that when they see some fault, a little bit of movement or clocking of the wheel behind the nut, that they’re out of service right then. I don’t care if your garage is 150 yards down the road, you do not move.”