Late last year, a parcel delivery truck was travelling eastbound on the 407 highway when one of its rear wheels suddenly came off. The hunk of rubber and metal jumped the median and smashed into a car heading westbound, sending it careening off the highway and into a ditch.

While that might sound like a fluke incident, runaway wheels from cars and light trucks are a surprisingly common sight on Ontario’s roads, experts say. In an average year, police in the Golden Horseshoe record around 100 of these wheel separations, and officials in Ontario’s Ministry of Transportation (MTO) estimate that, province-wide, the total could be in excess of 1,000 annually.

“This happens a lot more often than you think,” says Sgt. Kerry Schmidt of the Ontario Provincial Police (OPP). He responded to the incident on the 407 last year and, while no one was injured, Schmidt has seen several fatalities as a result of runaway wheels. “They are a tragedy waiting to happen,” he says.

Runaway wheels spike in spring

Most wheel separations happen in May and June, a couple of months after drivers have switched to their summer tires from their winter ones. That’s because some home mechanics and garages don’t use the most effective technique to properly tighten the retaining bolts and lug nuts that hold wheels in place, says Jeffery Turner, an engineer who specializes in vehicle safety with the MTO.

These fasteners need to be tightened to the torque (or tightness) specified by carmakers. Too little and fasteners will come loose. Too tight and the bolts can be damaged, eventually causing them to fail. “You don’t want to be outside the recommended torque,” Turner says. “Even a one-quarter turn can be too much.”

Home and professional mechanics alike should always use a torque wrench, not an impact wrench, breaker bar or cross-shaped lug wrench, when installing their tires, he adds. The torque wrench enables the installer to tighten fasteners as required by the vehicle manufacturer. He also recommends that do-it-yourselfers:

-inspect their rims, hubs and fasteners for damage before installing a wheel;

-thoroughly clean their wheels and hubs before positioning the wheel on the hub;

-after installing the fasteners, tighten them in stages, alternating from side to side until the manufacturer-recommended torque has been reached; and

-perform a torque check again, using a torque wrench, after the vehicle has been driven the distance recommended by the vehicle manufacturer. If in doubt about this interval, or the required tightening torque, DIYers should check their owner’s manual or consult their dealer.

Car owners who have their wheels changed in a garage should also have the torque checked after the vehicle has travelled the distance recommended by the technician. Many shops now offer this service for free, Turner says.

“Don’t blow that off,” he adds.

Drivers are responsible for their cars: experts

According to a report from the MTO, the OPP recorded 645 wheel separations on major highways in the Whitby-Toronto-Cambridge-Niagara corridor from 2013 through 2019, an average of 92 a year. Provincial statistics on wheel separations are not available, but Turner estimates the number, Ontario-wide, could be in excess of 1,000 annually.

Ultimately, drivers have a responsibility to make sure their vehicles are safe, says Andrew Davidson, a road safety manager at the MTO. If they aren’t careful and a wheel comes off, the consequences could be tragic, he says.

“When you lose a wheel at highway speed, it’s a cannonball. It’s dangerous for you and potentially deadly for someone else.”

Time for your spring tire change?

Let the expert technicians at CAA Mobile Tire Change swap your winter tires out this season, so you can go about your day. The best part? We come to you! Hurry, service is only available until May 31. Visit us at caasco.com/mobiletirechange to book your appointment today. .