At first glance, changing tires seems like a very routine process. However, despite its apparent simplicity, it demands engineering precision in handling and installation, especially for large truck tires. These tires are the rotating components of the commercial transport sector, which in turn stimulates local and international economies. Any error in the installation process can transform a safe journey into a dangerous and tragic nightmare. The American Highway Safety Organization conducted a study on fatal accidents, revealing that 15% of them are linked to mechanical problems and errors, with incorrect tire installation being a leading cause.
Improperly secured tires after changing are among the issues that contribute to an increased rate of accidents and roadside breakdowns on commercial routes. Beyond tragic accidents, there's a clear impact on performance. Tire performance is significantly linked to their installation and distribution method. Therefore, the installation process acts as a safety lock placed on tires to protect and ensure the safety of commercial roads. The function of lug nuts is to control the torque pressure that pulls the tires outward with high force.
Risks Resulting from Improper Tire Installation
Firstly: Wheel and Tire Separation While Driving
When a technician neglects to tighten the wheel bolts with the appropriate torque using a torque wrench, these bolts face a significant challenge: resisting intense and continuous vibrational forces throughout the truck's movement across varying terrains and environments. Over time, as the truck travels long distances for days and months, these vibrations can weaken the connection between the wheel and the hub. In many cases, severe looseness and loss of control occur, but the tires do not completely separate from the truck. However, in severe cases, or when bolts are missing or extremely loose, the wheel detaches from the truck, causing a real disaster on highways.
The severe consequences appear immediately upon wheel and tire separation. The driver loses control of the vehicle. If a front tire is lost, the truck will swerve severely off its path, whereas if a rear tire is lost, the truck loses its ability to balance. The situation is even more critical for rear-wheel-drive trucks and cars. Furthermore, a flying wheel can cause a chain of accidents, potentially colliding with other vehicles, leading to a series of crashes and stoppages, in addition to injuring pedestrians or damaging public and private property on the road. This danger is so severe that we liken a wheel detached from a truck to a rubber projectile that, if it strikes infrastructure, can cause significant damage. This underscores the importance of securely fastening wheels and verifying this before every journey to eliminate any doubt, as it is a precautionary measure that ensures everyone's safety.
In 2018, the U.S. National Highway Traffic Safety Administration (NHTSA) recorded 35 fatal accidents resulting from sudden wheel separation. Most of these cases were due to incorrect wheel and tire installation. One such accident occurred in Texas when a wheel detached from a transport truck, leading to a collision with a family car and causing three fatalities.
Secondly: Vibrations and Dynamic Instability
It should be noted that the danger of improper wheel installation is not limited to wheel separation; it extends beyond that, even if the tire does not completely detach. Dangers surround you everywhere, starting with continuous vibrations that cause the driver to lose dynamic stability on straight paths. These vibrations transfer to the truck's body through the suspension system. Damage spreads from the tires to the rim, and then reaches the entire suspension system and the truck itself. This leads to a series of negative consequences for vehicles. In the case of buses and passenger transport trucks, this causes noticeable and very disturbing discomfort for passengers. The situation worsens when we talk about commercial transport trucks, where you are dealing with goods and commercial materials worth double the entire truck's value. Exposing them to severe vibration and jolting makes them susceptible to damage and breakage. This harms the entrusted goods, thereby reducing trust in the truck driver and the logistics transport company responsible for the truck.
Among the cumulative damages that occur over time if the problem is not fixed are those affecting wheel bearings, which wear out faster than usual when there are vibrations and loss of stability, leading to doubled monthly maintenance costs. The impact on the wheel rim is evident through visible cracks and fatigue on its structure, especially in aluminum alloy rims, which are more susceptible to metal fatigue and thus more prone to disintegration and cracking. All these problems directly affect the structure of truck tires, causing irregular wear and bulges in the tire walls, which accelerates the end of their lifespan and again increases periodic maintenance costs.
Thirdly: Increased Fuel Consumption
The effect of improperly secured tires is primarily an abnormal increase in fuel consumption, resulting from the overall imbalance in the vehicle, which contributes to an increased engine load. Additionally, there's an increased friction between the tires and the road, forcing the engine to exert double the effort and burn more fuel to maintain the desired speed. Furthermore, increased fuel consumption in trucks is a sequential problem; it doesn't end at a specific point but continues to cause damage to the rest of the engine's internal and external components. Among the first parts to be damaged are the suspension and braking systems, followed by the engine's internal parts, which means we transition from a simple problem related to wheel mounting bolts to comprehensive engine maintenance.
Additional InformationMany people might wonder why increased tire friction affects higher fuel consumption. The simplified answer is that the larger the contact area of the tires, the more force is needed to move them. To elaborate further: the area in contact with the ground requires a certain force to transition from a state of rest to a state of motion. For every centimeter of this area, there is a corresponding Newtonian force (torque) produced by the engine. So, when tires are improperly installed or under-inflated, the tire's contact area increases, which increases the demand for kinetic force from the engine. This places an additional challenge on the engine, making it consume more fuel than if the contact area were normal and not imposing a significant load on the engine.
Fourthly: Unexpected Malfunctions!
Suspension System Damage:
When tires are installed incorrectly, unbalanced, or with lug nuts tightened to an improper torque, these errors generate high vibrations that transfer directly from the wheels to the front and rear linkages in the truck's suspension systems. This causes a buildup of dynamic pressures on the springs and hydraulic valves, which were not designed to withstand them. On the other hand, the damage extends to ball joints, which are literally the joints of the suspension system. Through them, vibrations reach the upper control arm. At this point, these parts begin to lose their ability to absorb high pressure and handle bends and turns smoothly and correctly. You might even hear noises and rattling from them. This indicates damage to these important parts, without which neither a truck nor a car can operate properly. This means increased downtime for maintenance and repairs, causing economic and financial problems for the driver and logistics companies.
Braking System Damage:
Incorrect tire installation or improperly tightened lug nuts can affect the rotor carrier, causing varying degrees of deviation. This deviation leads to a greater change in brake disc thickness (rotor runout), resulting in vibrations when the brake pedal is pressed. These continuous vibrations cause the brake pads to make uneven contact with the rotor, exposing specific areas to excessive pressure and heat. This results in uneven wear of the brake discs, leading to squealing and grinding noises. If this problem is ignored, the rotor may warp due to excessive pressure and high temperatures. All of this significantly increases the expected stopping distance, putting the vehicle at severe risk if the driver needs to brake at high speed.
It is clear how serious brake system damage can be, especially for commercial trucks on highways. An increased stopping time means the truck might not stop in the right place at the right time and could collide with what's in front of it before the driver can react effectively. These risks facing the driving community must be addressed and prevented through awareness and adherence to safety regulations.
Tire Pressure Monitoring System (TPMS) Malfunction:
The Tire Pressure Monitoring System (TPMS) includes precise internal sensors installed in the wheel spokes or the tire's inner air valve. The system's efficiency depends on correct tire installation, ensuring the valve is not touched by screwdrivers or other tools. Care must be taken to prevent the valve from being directly struck during installation or maintenance. In other cases, when tires are installed incorrectly and lug nuts are not properly tightened, often due to the use of traditional tools for wheel removal and installation that require axial force, the sensor itself may suffer a scratch or a fine crack in its body. This can cause a slow pressure leak in the tires without triggering an alert from the electronic system, as the damaged sensor cannot detect it.
Additionally, the sensor's internal battery may fail due to damage to its moisture-proof casing caused by fluctuating tire pressure. In such cases, the system may issue false alarms and warnings or stop working entirely, rendering the driver unable to know the tire pressure. This means no alert for any pressure drop that could allow the driver to avert a disaster, increasing the risk for the driver and other road users, in addition to excessive tire friction causing damage and blowouts. If a slow, undetected leak occurs, a sidewall bulge or a flat spot may appear on the tires due to using them partially inflated. This gradually degrades performance, shortens the tire's expected lifespan, and accelerates its premature replacement.
Speedometer Reading Discrepancy:
When tire size changes due to air leakage, or when tires of a different size than appropriate for the truck are installed, or in cases of significant tire damage and wear, the truck's speed measurement system partially malfunctions. The speedometer relies on the number of tire rotations, and its outer diameter changes due to damage and wear, creating a 3-5% error in the actual speed and distance readings. This noticeable discrepancy causes the driver to travel faster or slower than the posted speed limits, exposing them to risks and violations. All these problems are directly linked to the method of wheel installation and tightening, because, as previously stated, tires significantly impact all parts of the vehicle.
In addition to what we mentioned earlier, a significant difference in tire diameter causes a change in weight distribution on the suspension systems, which are responsible for steering the truck and distributing propulsive force. This increases the severity of vibrations and reduces the responsiveness of the Electronic Stability Control (ESC) system, as well as other auxiliary systems.
Neglecting proper tire installation doesn't just risk a wheel detaching while driving; it opens the door to a series of serious malfunctions. These begin with loss of vehicle control, progress to vibrations that damage suspension and braking systems, and end with increased fuel consumption, tire wear, and sensor damage... All this, simply because lug nuts weren't tightened to their proper torque.
How to Avoid These Problems:
Tire installation and maintenance are among the most critical factors for safety on commercial roads. Failure to properly and securely install lug nuts leads to serious accidents. Additionally, incorrect tool usage or neglecting regular inspections increases the risks during long journeys. In the following sections, we will discuss in detail how to avoid these problems:
First: The Correct Method for Tightening Lug Nuts
Precisely adjusting the tightening torque maintains balanced contact between the wheel and the hub, preventing wheel deviation or detachment while driving. If lug nuts are not tightened sufficiently, the wheel may lose its secure fastening; conversely, if overtightened, the wheel studs may stretch or break. The practical steps for tightening lug nuts are as follows.
Practical Steps for Correct Torque Adjustment:
A- Cleaning and Wheel Preparation: Ensure the studs, lug nuts, and wheel hub, especially the wheel openings, are free of rust and dirt, as dirt in these areas prevents full contact, leading to poor handling of metal expansion with heat.
B- Cross-Tightening Sequence: Mount the wheel on the hub, then hand-tighten the lug nuts in a cross (star) pattern until full contact is made between the nuts and the wheel surface. This method ensures better weight distribution and greater wheel stability.
C- Using a Calibrated Torque Wrench: Using a calibrated torque wrench, set to the appropriate tightening value according to the manufacturer's recommendations, complete tightening the lug nuts to the specified torque. For added safety, the lug nuts should be tightened in two stages, applying half the final torque in each stage, to avoid deformation or excessive stress on the equipment and the nuts.
D- Final Verification: After completing the process as required, review the steps and check the torque wrench reading to ensure the operation was completely successful and error-free.
What are the risks of neglecting this process?
As a result of tightening nuts below their specified and correct torque, the nuts will naturally loosen and be subjected to extreme stress that could cause them to detach from the studs, leading to complete wheel detachment. If this doesn't happen, the truck will suffer damage to parts connected to the tires, such as the braking and suspension systems.
Secondly: Quick Inspection Before Departure
Even when the torque is correctly set, nuts and studs are exposed to various factors. One such factor is early deviation due to the metal's properties and its attempt to settle into the new position. This is compounded by vehicle vibration during cargo loading and a rapid increase in pressure on the wheels. Experts therefore always recommend driving the vehicle or truck for a short distance, followed by a quick inspection of the nuts, wheels, and tires. This should extend to a visual inspection of the entire truck to ensure everything is in order before embarking on a long journey and maintaining the designated route. This quick check allows the driver to address issues before they become catastrophic and before the scheduled departure time for the assigned trip.
Practical Steps for the Quick Inspection:
a- Drive the vehicle cautiously for the first 100 kilometers, avoid long bridges or tunnels, and then stop to perform the quick inspection.
b- In a suitable and safe location, begin by ensuring the torque is set on all nuts by re-torquing them to the specified value.
c- Check that all nuts match the specified torque, as a discrepancy in the torque of any nut indicates a problem.
d- Check the rest of the truck's components, such as tires, water, oil, and air, and ensure you are ready for the journey.
Properly tightening nuts with a torque wrench not only protects the tires but also ensures the safety of the driver and vehicle, preventing potentially catastrophic accidents caused by wheel detachment during driving.
With this, we have covered the precautionary and preventive measures to ensure vehicle safety and to avoid issues arising from improperly tightened wheel nuts. Neglecting re-inspections and failing to confirm the truck's safety can expose you to situations we wouldn't wish upon anyone. This is because the area dedicated to securing the tires is exposed to many environments and changes, making it easily susceptible to oxidation, rust, loosening, breakage, and cracking. This is not surprising to anyone experienced in this field.
Indeed, Darbk Company for Tires works diligently to provide educational support to drivers and professionals in the logistics transport sector through articles, publications, and high-quality tires. While offering premium products specifically for the Saudi market, it has generously shared information and knowledge, presenting it on a silver platter in this Knowledge Library filled with insights and information that enriches the knowledge of truck drivers and logistics fleet owners.
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