Diagnosing Vibrations

No factor contributes to a negative operating experience more than vehicle vibration. The torment of operators everywhere, it degrades ride quality, shortens tire life, and strains vehicle components. Fortunately, steps can be taken to avoid operating under these conditions.

  1. Visually inspect tires, wheels/rims and vehicle for irregular wear, damaged wheels/rims, or vehicle component damage. Replace or adjust as required.
  2. Check to be certain that tires are inflated according to vehicle manufacturer recommendations and the vehicle suspension is working correctly and vehicle is not tilting. Either bias ply or radial tires can be mounted on the steer axles if the vehicle has multiple drive axles.
  3. Check each tire to be certain it is mounted properly on the wheel/rim. The tire fitting line should be concentric with the rim flange. If the tire has a yellow or red mark on the tire, it should be oriented to the rim correctly.
  4. Test drive vehicle on a smooth road surface and diagnose symptoms. 5-to-10 mile warm-up is recommended to remove any flat spotting. Steering wheel vibration diagnosis should begin with front axle, wheel, and tire conditions and floor or seat vibration diagnosis should begin with drive axle. Power train and brake conditions can be diagnosed by alternate brake application and placing the transition into neutral during vibration.
  5. Check each tire wheel/rim assembly balance and adjust as required. If unable to balance, completely deflate tire, unseat tire beads, and rotate tire 180 degrees on the wheel/rim. Inflate, rebalance and reinstall on vehicle.
  6. If vibration is not eliminated, measure tire and wheel/rim assembly for excessive lateral or radial run-out. Replace as required.
  7. Rebalance tire and wheel/rim assembly and test drive vehicle.

TIRE BALANCE, VEHICLE RIDE, AND VIBRATION

By design, Yokohama’s radial tires are constructed with lower aspect ratios than ever before. This allows them to respond to lateral forces more effectively meaning it takes less time to transmit the steering input from the wheel to tread. This improved steering response means better performance on the road but requires special attention be paid to proper tire mounting, balancing, and installation procedures to ensure that optimal ride quality is achieved. Vigilant attention to these details and regular maintenance will maximize your vehicle is performance and guarantee a smooth, comfortable ride—mile after mile.

Tire Vibration Causes

TIRE BALANCE UNIFORMITY

Day-to-day wear causes changes in the distribution of weight around the tire and wheel assembly, which can cause vibration. Balancing your wheels minimizes potential vibration felt in the steering wheel, seat, or floorboard and improves tire longevity.

Types of Imbalance

1.Static Imbalance

Occurs when there is a heavy or light spot in the tire so that the tire won’t roll evenly and the tire/wheel assembly undergoes an up-and-down movement. Correcting static balance: Achieved with a bubble or spin balancer.

Static Imbalance Tire

2.Dynamic Imbalance

Occurs when there is a heavy or light spot in the tire so that the tire won’t roll evenly and the tire/wheel assembly undergoes an up-and-down movement. Correcting static balance: Achieved with a bubble or spin balancer.

Dynamic Imbalance Tire

3. Vehicle Imbalance

Vibration due to faulty vehicle components other than the tire or wheel/rim assembly; such as hubs, brake rotors and drums and drive lines. Correcting vehicle imbalance: Correction requires checking for any irregularities and replacement as required.

Vehicle Imbalance Table
4.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. A small degree of this imbalance is acceptable, but too great a run-out causes vibration and excessive tire wear. There are two types of run-out imbalance, radial and lateral:

Radial Run-out

An “out-of-round” situation where vibrations are produced as the wheel spindle moves up and down. Correcting radial run-out: Achieved by rotating the wheel and tire assembly two stud positions on the hub, or by rotating the tire 180 degrees on the wheel. If run-out is still over specification, check wheel run-out and mark the low point. Rotate to match the high point of the assembly run-out with the wheel low point. If the assembly run-out is still too high and the wheel is within specification, replace the tire.

Lateral Run-out

A side-to-side or wobbling movement of the tire and wheel. Less common than radial run-out, as the sensitivity of a vehicle to vibration from lateral run-out gauge to check both the tire and wheel. Chalk mark the highest point of run-out both the wheel and tire then replace whichever (wheel, tire or both) is out of specification.