Common Causes of Uneven Tire Wear
Misalignment
One of the leading causes of uneven tire wear is wheel misalignment. Trucks that are out of alignment often show feathering or edge wear on the tires. Misalignment affects the camber, toe, and caster angles—three critical factors in wheel positioning. If these angles are off, tires won’t roll evenly across the pavement, leading to accelerated tread degradation.
Alignment issues can arise from:
- Impact with curbs or potholes
- Worn suspension components
- Improper ride height due to suspension sag
Routine alignment inspections should be part of your regular maintenance schedule, especially after any suspension repair.
Underinflation or Overinflation
Tire pressure plays a vital role in how your tires wear. Underinflated tires often exhibit wear on the outer edges, while overinflated tires wear down the center of the tread. Either condition can significantly reduce tread life and increase the risk of a blowout.
For heavy-duty trucks, air pressure isn’t just about tire health—it directly impacts load distribution and braking performance. Be sure to:
- Use a calibrated tire gauge
- Check pressures cold, before driving
- Adjust pressures according to manufacturer specs and load rating
Suspension System Failures
A failing suspension system can create erratic and inconsistent tread wear. Worn shock absorbers, leaf springs, or air bags can cause tires to bounce excessively, leading to cupping or scalloping patterns on the tread. These high-low spots are a sign that your tires are not maintaining steady contact with the road.
Suspension inspection should include:
- Shock absorber leaks or wear
- Loose bushings or broken leaf springs
- Uneven air pressure in air suspension systems
Even with a new set of tires, worn suspension components will quickly destroy tread integrity if not corrected.
Faulty Wheel Bearings
Worn wheel bearings can cause radial runout, which is when a tire wobbles or moves side-to-side. This motion causes rapid and irregular wear, typically noticeable on one side of the tire. You may also hear a growling or humming noise while driving—a telltale sign of bearing failure.
Inspect bearings for:
- Excessive play or looseness
- Overheating and signs of metal-on-metal contact
- Lack of grease or failed seals
Tires worn from bearing failure often need replacement, as the wear pattern compromises safety.
Uneven Load Distribution
Uneven tire wear can result from how the truck is loaded. A poorly balanced load—either side to side or front to back—puts more weight on certain axles or corners. The result is accelerated wear on one or two tires instead of uniform wear across all positions.
Preventive tips include:
- Properly training drivers or loaders
- Weighing cargo with onboard scales
- Using air suspension leveling systems to balance weight
Truck suspension is engineered to support balanced weight. When that balance is disrupted, tires pay the price.
Identifying Tire Wear Patterns
- Feathering: Tread feels smooth on one side and sharp on the other; typically caused by wheel misalignment.
- Cupping: Scalloped dips around the tread; often due to worn shocks or suspension components.
- Edge Wear: Excessive wear on the inner or outer shoulders; usually linked to underinflation or camber misalignment.
- Center Wear: Tread worn more in the middle; commonly caused by overinflation.
- Spot Wear: Isolated flat spots on the tread; often a result of locked brakes or tire imbalance.
Each pattern signals a deeper issue—identifying and addressing them early can prevent further damage and extend tire life.
Proactive Steps to Prevent Uneven Wear
Routine Tire Rotations
Rotating tires ensures that each tire experiences different positions, load stresses, and wear angles over time. This promotes even tread wear and maximizes the life of your tire investment.
Industry best practice: rotate every 6,000 to 8,000 miles or during every preventive maintenance service.
Precision Alignments
Don’t rely solely on visual inspections. Professional alignment equipment can diagnose subtle angle deviations that are invisible to the naked eye. Keep alignment records for each truck in the fleet, and ensure alignments are done post-suspension service.
Maintain Proper Tire Pressure
Implement a tire pressure monitoring system (TPMS) if one isn’t already installed. These systems provide real-time data to the driver and maintenance team, reducing the risk of unnoticed pressure drops.
Replace Worn Suspension Components
Shock absorbers, air springs, and leaf spring hangers don’t last forever. A preventive maintenance schedule should include regular inspections and replacements based on mileage or wear indicators.
Load Evenly and Responsibly
Train staff to understand the impact of cargo loading on suspension systems and tire life. Where possible, use onboard load balancing systems or tools to validate even weight distribution.
The Cost of Ignoring Uneven Tire Wear
Letting uneven tire wear persist can lead to:
- Premature tire replacements
- Decreased fuel economy
- Increased downtime from tire-related roadside issues
- Poor handling and compromised braking
- Damage to other systems (suspension, axles, hubs)
Given the cost of commercial-grade tires and the risk to driver safety, addressing wear proactively is not just good practice—it’s a necessity.
Recap
Uneven tire wear is a symptom of deeper mechanical or operational issues. Whether it's misalignment, poor suspension health, or simply incorrect air pressure, the effects can be costly and dangerous. By regularly inspecting tires, aligning axles, maintaining correct pressures, and loading responsibly, you can dramatically extend the life of your tires and reduce overall operating costs.
If you require truck tire maintenance in Downingtown, PA, reach out to our team at FMI Fleet Service today.
