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What Every Manager Of Commercial Fleets Needs To Know About Wheel Separation

22 June 2017

Stanley Garcia

According to the transportation industry website Trucking Info, it is estimated that several hundred wheels separate from trucks unexpectedly every day. However, the exact number of wheel separations is difficult to determine because not all are reported. Sometimes, the lost wheel isn't immediately discovered by the truck driver, even when the wheel causes an accident. 

If you manage a commercial fleet, it's important that you understand the risks of wheel separations and how to avoid them. Here's what you need to know. 

Damaged Caused by a Wheel Separation Can Be Catastrophic 

In Ontario, a 69-year-old man died after being struck by a flying wheel that had separated from a vehicle and struck the windshield of the vehicle he was driving. It caused him to lose control of his vehicle as the force of the flying wheel caused the entire roof of his SUV to collapse, trapping him. Tractor trailer tires can weigh 100 pounds and travel more than 60 mph, causing destruction in it's path. Due to truck drivers typically being unaware of wheel separations when they occur from their trailers, they may not know any accidents were caused until after someone reports the incident to law enforcement. 

3 Common Causes of Wheel Separation from Semi Trucks & Trailers 

There are three common causes of wheels separating from semis and trailers. It's important to understand what these causes are so you can mitigate the risks of having them occur in your commercial fleet. 

• Broken axle. A broken axle can cause the axle to break free, which can cause the axle and wheel to separate from a moving vehicle. Broken axles can occur due to overwhelming stress on areas, such as when the frame is bent, which can cause fatigue failure. It can also occur to axles that have had the strength of the metal compromised metallurgically due to excessive heat from welding or torches. 
• Separated hub. The wheel hub assembly is what wheels are mounted to and is located in between the axle and brake drums or discs. The wheel hub assembly can separate due to faulty wheel bearings or axle spindle nuts. The wheel hub assembly can be damaged by hitting pot holes or by being involved in a collision. Bearings and axle spindle nuts can wear out over time. 
• Failure of fasteners. Fasteners are wheel nuts that are secured to wheel studs. These fastening assemblies have a clamping force that hold the wheel and brake components in place If the nuts are not properly tightened, they can loosen over time and cause the wheel to separate from the semi or trailer. Wheel studs can break off due to stress fractures, which is called reversed bending fatigue, and release the wheel as well. 

Since most vehicles in commercial fleets are on the roadways day in and day out, it is crucial to reduce the risks of wheel separation. 

Tips to Prevent Wheels Separating from Semis & Trailers In Your Fleet 

Now that you have an understanding of the various common causes of wheel separation, it is important to take preventive measures to reduce the risks of this phenomenon from happening to semis and trailers in your fleet. One way to do this is to have a commercial fleet repair service routinely inspect each part that is prone to breakage.

Consider hiring a commercial fleet service that specializes in body and mechanical parts. The reason for this is because bent frames of semis and trailers can add to the fatigue seen in axles and wheel studs, which results in failures that can separate wheels and send them hurling into traffic. Also, ask this service to train your truck drivers to perform daily inspections of the wheels and axles. For more information, check out the sites like this one.

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