Published on April 26th, 2018 | by Guest Contributor

Don’t Let the Wheels Come Off – How to Prevent Wheel Separation.

The 1990’s saw a sharp increase in incidents where wheels separated from commercial vehicles, many of which caused serious injuries and fatalities in Ontario. Both the government and the trucking industry took action, and improvements were made in inspection and maintenance practises.  As a result, the number of incidents decreased sharply.

Recently, the province has become aware of similar issues with light-duty vehicles, including passenger vehicles, pick-up trucks, SUVs and minivans as reported by the Ontario Provincial Police (OPP) in southern Ontario.

A study of the reported incidents, carried out by Ontario’s Ministry of Transportation (MTO), revealed that over the 4- year period, there was a total of 389 reported wheel separations from light-duty vehicles in the monitored region. Of these, 29% had resulted in a collision.

How Does Wheel Separation Happen?

According to the MTO, wheel separations occur throughout the year however there is a spike in occurrences during the spring and early summer months. Analysis of reports indicate that most incidents resulted from loose wheel fasteners – the lug nuts or bolts that hold the wheel on the vehicle.

Furthermore, it was noted that a majority of these incidents in the spring-summer occurred with aluminum wheels. This is significant because seasonal tire changes generally involve the installation of aluminum wheels in the spring, while steel wheels (on which winter tires are usually mounted) are most common in the fall.

Since loose wheel fasteners cause most light-duty vehicle wheel separations, it is important that individuals who are installing wheels follow a few simple safety procedures:

  • INSPECT the wheel before it is installed on the vehicle. It is important to check the hub and other components on the vehicle. If anything appears damaged or loose, it is recommended that it be assessed by a qualified technician. Ensure that the hub, where the wheel will be installed, is clean and free from excessive corrosion. Check the centre of the wheel to be installed, where it will mate with the hub, again for dirt and excessive corrosion.
  • CLEAN the mating surfaces of the wheel and hub. The rim must completely contact the hub, without interference from metal burrs or contaminants. Fasteners and mating parts should be clean and undamaged. Clean or replace as required. They should turn freely up to the rim, which should be in full contact with the hub behind it.
  • TIGHTEN the fasteners to the correct torque using a torque wrench. Tighten in a “star” pattern, meaning, alternating from one side of the rim to the other, as each fastener is tightened. The final tightening must be to the torque specified by the vehicle manufacturer. Obtain the tightening torque from your vehicle’s owner’s manual or contact the dealer.
  • CHECK fastener torque after the vehicle has been operated a certain number of kilometres, as specified by the vehicle manufacturer. If the manufacturer doesn’t specifically recommend a torque check, you may still want to perform one to ensure that fasteners have not loosened since their installation. Simply put the torque wrench on each fastener and increase tightening torque to the recommended limit. If any of the fasteners move significantly it may indicate a problem with the original installation.

It is important to remember that a vehicle owner is responsible for proper maintenance of their vehicle. The Highway Traffic Act has no specific charge for wheel-off incidents involving private passenger vehicles, however should the incident result in a collision, and depending on the circumstances, one could face a penalty for driving an unsafe vehicle, or even careless driving.  Maintaining your vehicle in good working order is one step to help avoid these incidents from occurring.

If you are unsure about any part of the installation of a wheel on your vehicle, it is recommended that you take the vehicle to a qualified shop for its seasonal tire change.

CAA’s Consumer and Technical Services (CATS) team provides Members with free automotive advice. If you have questions about car care, buying a new or used vehicle, auto repairs, vehicle inspection, driving costs and more, contact CATS by phone 1-866-464-6448 or email 

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