Wheel-end violations inspector taking notes

The Commercial Vehicle Safety Alliance (CVSA) will host the annual International Roadcheck May 17-19 with a focus on wheel ends, which include the wheels, rims, hubs and tires on a commercial motor vehicle.


Wheel-end components support the heavy loads carried by commercial motor vehicles (CMVs), maintain stability and control, and are critical for braking. Violations involving wheel-end components historically account for about one quarter of the vehicle out-of-service violations discovered during International Roadcheck, and past International Roadcheck data routinely identified wheel-end components as a top 10 vehicle violation.

"Wheel ends contain numerous moving parts, whether it is the brake system, the bearings or the hubs, that can leak, wear or seize due to lack of lubrication. There are a lot of moving parts, and a good maintenance program is key to eliminating any issues," said Chris Hough, vice president of maintenance design and engineering for Penske Truck Leasing.

Wheel-end failures may lead to a catastrophic crash. "When a wheel end fails, say a bearing seizes and you have a wheel run-off situation, it can cause a lot of damage," Hough said, adding that wheel-end fires often result from brake system air leaks that prevent the brake chamber from completely releasing the brake.

Completing pre- and post-trip inspections are one of the best things drivers can do to help prevent issues. "Check the wheel-end brake system for air leaks, proper adjustment, etc., write them up and have them addressed by a qualified technician before heading out," Hough said.

Wheel seals, lube levels and lug nuts are among items that should be inspected daily, Hough said. Drivers' observations during the inspection are the first step in detecting a wheel-end problem.

CVSA said drivers may also find abnormal or uneven tire wear, see or smell smoking or extremely hot hubcaps (too hot to touch), notice smoke from a wheel end, or feel wheel vibration, wobble or noise. Increased stopping distance or decreased braking power, abnormal side pull when braking, wheel lock-up or skidding are all signs that wheel ends may need maintenance or replacement.

During Inspection of Wheel Ends on a Commercial Motor Vehicle, Inspectors Will:

  • Check for cracks or unseated locking rings, studs or clamps.
  • Check for bent, cracked or broken rims on the inside and outside wheel rims.
  • Check for loose, broken, missing or damaged wheel fasteners and elongated stud holes.
  • Check spoke wheels for cracks across spokes and in the web area or slippage in the clamp areas.
  • Check the hub for lubricant leaks, missing caps or plugs.
  • Check the inner wheel seal for leaks.
  • Check the tire and valve stem for leaks.
  • Check for improper inflation, cuts and bulges on all tires, including the inside tire on a dual set.
  • Check for regrooved tires on steering axle.
  • Check tread wear and measure major tread groove depth.
  • Inspect the sidewall for improper repairs, such as tire plugs.
  • Check for exposed fabric or cord.
  • Check for tire contact with any part of the vehicle.
  • Check for markings on the tire that would exclude its use on a steering axle.
  • Check for debris between the tires.
  • Check for tires touching one another or any part

Hough added that drivers and technicians also need to be careful not to over-torque lug nuts, which will stretch the stud. "Once a wheel stud is stretched, the stud will never maintain the correct torque," he said.

The residual damage from over-torquing a lug nut could take months to develop, but eventually will cause problems. "A bolt/stud acts as a tension/clamping device when torqued properly. If over-torqued, it loses the ability to maintain the correct clamping force," Hough said.

About International Roadcheck

International Roadcheck is a 72-hour, high-visibility, high-volume commercial motor vehicle inspection and enforcement initiative. Commercial motor vehicle inspectors in Canada, Mexico and the U.S. will conduct North American Standard Inspections of commercial motor vehicles and drivers at weigh and inspection stations, on roving patrols, and at temporary inspection sites.

During International Roadcheck, commercial motor vehicle inspectors examine large trucks and motorcoaches and the driver’s documentation and credentials using CVSA’s North American Standard Inspection Program procedures, which are the uniform inspection steps, processes and standards established to ensure consistency in compliance, inspections and enforcement.

Using the North American Standard Out-of-Service Criteria, also established by CVSA, inspectors identify critical out-of-service violations that if found, require the inspector to restrict the driver or vehicle from travel until those violations or conditions are addressed.

Vehicles that successfully pass a North American Standard Level I or Level V Inspection without any critical vehicle inspection item violations may receive a CVSA decal. In general, a vehicle with a valid CVSA decal will not be reinspected during the three months while the decal is valid. Instead, inspectors will focus their efforts on vehicles without a valid CVSA decal.

"We want every vehicle on our roadways to be in proper working order for the safety of the driver operating that vehicle and everyone traveling on our roadways," said CVSA president Capt. John Broers with the South Dakota Highway Patrol.

April 2022