Maintenance & Care
Tire Balance, Vehicle Ride and Vibration
Maintaining your tires for the long haul.
Today’s radial tires are constructed with lower aspect ratios than ever before for better on-road performance. But they’re also more sensitive to mounting errors and require vigilant attention to regular maintenance.
Day-to-day wear can also affect the balance of the tire, causing vibration. So be sure to balance your tires at regularly scheduled intervals for a smoother, more comfortable ride and longer-lasting performance.
Mounting Guidelines and Warnings
- Improper mounting, underinflation, overloading or tire damage may result in tire failure, which may lead to serious injury.
- Tire and rim sizes must correspond for proper fit and application. Never exceed 40 psi to seat beads.
- Tire changing can be dangerous and should be done only by trained persons using the proper tools and procedures established by USTMA.
- Failure to comply with proper procedures may result in incorrect positioning of the tire, tube, or wheel assembly, causing the assembly to burst with explosive force sufficient to cause serious injury or death.
- Never mount or use damaged tires, tubes or wheel assemblies.
Failure to comply with the following tire demounting/mounting safety precautions can cause the bead to break and the assembly to burst with lethal force.
- Always deflate tire completely before removing lock or side rings.
- Never use rim parts of different manufacturers or different size.
- Never mount tires on rims which are damaged or not smooth and clean.
- Always clean and inspect the rim. Lubricate beads and rim flanges, tube & rim side of flap with approved rubber lubricant.
- Always be sure that rim components are properly seated before inflating.
- Always use an extension hose with gauge and clip-on chuck.
- Always use a safety cage or other restraining device when inflating the tire to seat the beads or to inflate to normal operating inflation pressure.
- Never inflate beyond 275kPa (2.75 bar, 40 psi) to seat the beads.
- Never stand, lean or reach over the assembly during inflation.
- After beads are fully seated, adjust to vehicle manufacturer’s recommended inflation pressure.
- Never mount radials on the same axle with bias tires. Follow vehicle manufacturer’s recommendations.
- Tires must be removed when remaining tread depth reaches regulated measurement in your jurisdiction.
- Moisture in tires can damage the casing. Always store tires in a dry area, dry the interior before mounting and inflate with dry air.
Mounting Directional Tires
When mounted properly, directional treads prevent block squirm, effectively reducing irregular wear and improving tread life.
Direction of Rotation
The tread pattern should face the front of the vehicle when viewed from the top.
Directional treads should be mounted to ensure their “direction of rotation” arrows on the sidewall are each pointed to the front of the vehicle.
Run-Out and Match Mounting
Yokohama places red and yellow marks on the sidewalls of its tires to enable the best possible match-mounting of the tire/wheel assembly.
There are two methods of match-mounting Yokohama tires to wheel assemblies.
Uniformity Method (red mark)
The red mark on the tire, indicating the point of maximum radial run-out, should be aligned with the wheel assembly’s point of minimum radial run-out, which is generally indicated by a dimple somewhere on the wheel assembly (consult manufacturer for details).
Weight Method (yellow mark)
The yellow mark on the tire, indicating the point of lightest weight, should be aligned with the valve stem.
No factor can ruin a good ride more than vehicle vibration. Vehicle vibration degrades ride quality, shortens tire life and strains vehicle components. Fortunately, steps can be taken to avoid operating under these conditions:
- Visually inspect tires, wheels, and vehicle for irregular wear or damage.
- Evaluate tire inflation and suspension components.
- Check each tire to be certain it is mounted concentrically to the rim and properly match-mounted.
- Test drive the vehicle on a smooth road surface and diagnose symptoms. Focus troubleshooting on the steer axle for steering wheel vibrations and drive axle for floor or seat vibrations.
- Check each tire wheel/rim assembly balance and adjust as required. Dismount and remount if needed.
- If vibration is not eliminated, measure tire and wheel/rim assembly for excessive lateral or radial run-out.
- Rebalance tire and wheel/rim assembly and test drive vehicle.
Factors that Influence Vehicle Vibration
Any number of different vehicle components can cause vibration, from wear, rattle or component damage on the vehicle itself, to the tire choice and how they’re used.
- Drive Mechanism
- Axle Shaft
- Propeller Shaft
- Rear Suspension
- Front Suspension
- Engine Body
- Intake/Exhaust System
- Engine Mounting System
- Tire Radial Run-Out
- Tire Imbalance
- Tire Manufacturing
- Improper Tire Storage
- Tire Size
- Tire Wear
- Concentric Tire Mounting
- Wheel Run-Out
- Flat Spot
- Tire Setup
- Road Surface
- Velocity (Speed)
- Road & Environment
Types of Imbalance
There are four main types of imbalance that can cause vehicle vibration.
Static imbalance occurs when there is a heavy or light spot in the tire so that the tire won’t roll evenly, causing the tire/wheel assembly to move up and down. Correcting static imbalance can be achieved with a bubble or spin balancer.
Dynamic imbalance occurs when nonuniformity in the tire creates lateral forces as the tire rolls, causing tire/wheel assembly wobble. Most spin balancers can use multiple weights to simultaneously correct static and dynamic imbalance.
Vehicle imbalance occurs as a result of faulty vehicle components other than tire or wheel/rim assembly, such as the hubs, brake rotors and drums, or drive lines. Correcting vehicle imbalance requires checking for any irregularities and replacement as needed.
Run-out imbalance results from poor bead-seating on the rim or improper placement of components. Poor bead seating is usually the result of improper mounting or the use of wheels with imperfections. While a small degree of this imbalance is acceptable, too great of a run-out causes vibration and excessive tire wear.
Radial run-out is an “out-of-round” situation where vibrations are produced as the wheel spindle moves up and down. To correct this, rotate the wheel and tire assembly two stud positions on the hub, or by rotating the tire 180 degrees on the wheel.
Lateral run-out is a side-to-side or wobbling movement of the tire and wheel. Less common than radial run-out, this type of imbalance can be checked with a lateral run-out gauge on both the tire and wheel.