As a result of advancements in automotive technology, today’s tire and wheel/rim fitments require special attention. By design, radial tire construction and low aspect ratios contribute to a vehicle’s ride and handling quality. Proper tire mounting, balancing and installation are critical to attaining a smooth vehicle ride. Vehicle vibrations and a suspected problem tire may be due to an improperly balanced tire and wheel assembly or related to the mechanical condition of the vehicle. Vibration is the most noticeable effect of imbalance and is dependent on vehicle speed and may be felt in the steering wheel, seats or floor board. It often first becomes apparent between 40 and 45 mph and changes in magnitude with greater speeds. The following is a step-by-step process on preventing vibration issues on new tire installations and addressing vibration issues from customers returning after experiencing noticeable ride vibrations.
What is the first process a technician should use to solve a wheel vibration issue?
Stage 1-Optimizing Program (match-mounting by weight)
This program match-mounts the heavy spot of the wheel to the light spot of the tire. Some tire manufactures will have a colored dot that can be used in lieu of this program which addresses static imbalance and is the most noticeable form felt by the driver. The wheel assembly will be balanced to the most optimal level.
Technician is NOT required to drive 5 to 10 miles on cold tires as to remove any flat spots prior to performing this program.
What should a technician do if a wheel vibration still exists?
Stage 2-ROD Program (match-mounting by shape)
This program is used to reduce road noise (vibrations) to a minimum when caused by geometrical mismatch. Road noise can still be present even after balancing, therefore a possible solution which attempts to minimize such disturbances is to compensate any geometrical mismatch between tire and rim. To be used after using the Corghi Optimizing Program to address unresolved vibration issues and/or to compare run-out measurements to maximum tolerances. The wheel assembly will be geometrically match-mounted and balanced.
Technician is required to drive 5 to 10 miles on cold tires as to remove any flat spots prior to performing this program.
What additional steps can a technician do to give a vehicle the smoothest possible ride?
Stage 3-iPos Program (Intelligent Positioning on Vehicle)
This program is used to automatically detect the optimal positioning of the wheel assemblies on the vehicle by selecting one of the following criteria:
- Tread wear
- Tire side slip
- Radial run-out
- Wheel unbalances
The vehicle will be configured to the optimal achievable level for comfort.
The Optimization Program is standard on all Corghi Wheel Balancers. Our Diagnostic Wheel Balancers match mount tires and wheels by the combined shape of the wheel assembly and/or the combined weight of the wheel assembly. These capabilities allows the operator to initially install/match-mount the wheel assembly by manufacturer’s specifications or to match-mount based on lateral and radial run-out measurements. In addition to these features, the wheel balancer is able to suggest the optimal positioning of the wheel on the vehicle by tread wear, tire side slip, radial run-out or wheel assembly unbalances.
Information provided by: Corghi USA
