Heating of the wheel hub is a very common phenomenon during long-distance heavy loading of heavy trucks, downhill operations in mountainous areas, and high-frequency operations on construction sites. A slight temperature rise during normal driving is considered a normal operating condition, but if there is abnormal high temperature such as wheel hub overheating, smoking, or even tire overheating, it must be promptly investigated and dealt with. Many overseas fleets often attribute the high temperature of wheel hubs to bearing problems and blindly replace parts, which not only fails to cure the problem but also increases unnecessary maintenance costs. The causes of abnormal heating of the wheel hub are concentrated in four directions: braking, bearings, tire pressure load, and assembly adjustment. By investigating in sequence, the root cause of the problem can be quickly located, and the risk of bottoming out and tire blowouts can be avoided.
Prioritize investigating the issue of brake system drag, which is the primary cause of high wheel hub temperature. Poor return of the service brake and parking brake of heavy trucks is the most common cause of high temperature in single-sided wheel hubs. Brake cylinder sticking, fatigue of brake shoe return spring, and short stroke of air chamber push rod can cause the brake pads to slightly adhere to the brake drum for a long time, resulting in continuous friction and heat generation during driving, causing the wheel hub to rapidly heat up. Especially in mountainous areas, frequent braking, water ingress in the air circuit after rain, and valve body jamming can easily lead to brake drag. If there is a high temperature on one side of the wheel hub, slight deviation of the vehicle, and a shorter sliding distance, it can be basically judged as poor brake return, and the brake mechanism and air circuit valve body need to be repaired in a timely manner.
Next, investigate the wheel hub bearings and lubrication status. Excessive or insufficient bearing clearance, loose wear, or missing or deteriorated lubricating grease, as well as emulsified water ingress, can all lead to a significant increase in bearing operating resistance and overheating due to friction. Long term heavy load bumps, road water accumulation, and water ingress during car washing can damage the lubrication environment of bearings and cause dry grinding and heating. This type of malfunction is often manifested as continuous heating of the wheel hub, buzzing noise during driving, and slight shaking of the wheel. Under dusty and rainy working conditions overseas, bearing seal failure and grease failure are common issues that require regular inspection of lubrication status and adjustment of standard clearances.
Check for abnormal heating caused by tire pressure, load, and road conditions. Abnormal tire pressure is an easily overlooked cause of temperature rise: low tire pressure, repeated compression and deformation of the tire sidewall, rapid increase in tire temperature and transmission to the wheel hub; Excessive tire pressure reduces the contact area between the tire surface and the ground, leading to localized stress concentration and exacerbating heat accumulation. At the same time, long-term overloading and off load driving, wheel hub overload, continuous compression friction, and temperature will far exceed the normal range. Frequent potholes and bumpy road surfaces, coupled with continuous impact and vibration from the wheels, can also increase the load on bearings and brakes, leading to abnormal heating.
Finally, check for improper assembly and adjustment issues. After vehicle maintenance, drum replacement, and bearing maintenance, if the assembly is not standardized, there is a high risk of high temperature hazards. For example, adjusting the brake clearance too small, the bearing pre tension is unreasonable, the torque of the wheel hub screws is uneven, and the brake drum is out of roundness and deformed, all of which can cause continuous friction and uneven force during driving, leading to abnormal wheel hub temperature. Many new cars and newly maintained vehicles experience high temperatures, mostly due to non-standard assembly and debugging, rather than quality issues with accessories.
Summary of troubleshooting logic: First check for brake drag, then check for bearing lubrication, then check for tire pressure and load, and finally check for assembly clearance. During daily inspections of overseas fleets, high temperatures were found in the wheels. Following this sequence of troubleshooting can quickly and accurately solve the problem, eliminate safety hazards such as bearing burning, tire blowouts, and fires, effectively reduce maintenance costs, and ensure stable vehicle operation.
