## What is Wheel and Tire Assembly Run Out?
Wheel and tire assembly run out is a measurement of how much the wheel and tire assembly deviates from a perfect circle. This deviation can be caused by a variety of factors, including:
Wheel manufacturing defects: These defects can include out-of-round wheels, bent wheels, or wheels with uneven spoke tension.
Tire manufacturing defects: These defects can include out-of-round tires, tires with uneven tread wear, or tires with sidewall bulges.
Improper mounting and balancing: If the wheel and tire assembly is not properly mounted and balanced, it can cause the assembly to run out of true.
### Types of Wheel and Tire Assembly Run Out
There are two main types of wheel and tire assembly run out:
Radial run out: This is a measurement of how much the wheel and tire assembly deviates from a perfect circle in the radial direction (i.e., up and down).
Lateral run out: This is a measurement of how much the wheel and tire assembly deviates from a perfect circle in the lateral direction (i.e., side to side).
### Causes of Wheel and Tire Assembly Run Out
The most common causes of wheel and tire assembly run out are:
Wheel manufacturing defects: These defects can include out-of-round wheels, bent wheels, or wheels with uneven spoke tension.
Tire manufacturing defects: These defects can include out-of-round tires, tires with uneven tread wear, or tires with sidewall bulges.
Improper mounting and balancing: If the wheel and tire assembly is not properly mounted and balanced, it can cause the assembly to run out of true.
### Symptoms of Wheel and Tire Assembly Run Out
The symptoms of wheel and tire assembly run out can include:
Vibration: Wheel and tire assembly run out can cause the vehicle to vibrate at certain speeds. This vibration can be felt in the steering wheel, the seat, or the floorboard.
Noise: Wheel and tire assembly run out can also cause the vehicle to make noise, such as a humming or growling sound. This noise can be heard at certain speeds or when the vehicle is turning.
Uneven tire wear: Wheel and tire assembly run out can cause the tires to wear unevenly. This can lead to premature tire failure and decreased fuel economy.
Poor handling: Wheel and tire assembly run out can also affect the vehicle’s handling. The vehicle may pull to one side or the other, or it may be difficult to steer.
### Diagnosis of Wheel and Tire Assembly Run Out
Wheel and tire assembly run out can be diagnosed by a qualified mechanic using a variety of tools, including:
Dial indicator: A dial indicator is a precision instrument that can be used to measure the radial and lateral run out of a wheel and tire assembly.
Runout gauge: A runout gauge is a specialized tool that is designed to measure the run out of a wheel and tire assembly.
Laser alignment system: A laser alignment system can be used to measure the alignment of the wheel and tire assembly and to identify any run out.
### Treatment of Wheel and Tire Assembly Run Out
The treatment of wheel and tire assembly run out depends on the cause of the problem. If the run out is caused by a wheel manufacturing defect, the wheel may need to be replaced. If the run out is caused by a tire manufacturing defect, the tire may need to be replaced. If the run out is caused by improper mounting and balancing, the wheel and tire assembly may need to be remounted and balanced.
### Prevention of Wheel and Tire Assembly Run Out
There are a few things that you can do to prevent wheel and tire assembly run out, including:
Have your wheels and tires inspected regularly by a qualified mechanic. This will help to identify any potential problems early on, before they can cause serious damage.
Have your wheels and tires mounted and balanced by a qualified mechanic. This will help to ensure that the wheel and tire assembly is running true.
Avoid hitting potholes and other road hazards. This can damage your wheels and tires and cause them to run out of true.
### Conclusion
Wheel and tire assembly run out is a common problem that can cause a variety of symptoms, including vibration, noise, uneven tire wear, and poor handling. If you suspect that your vehicle has wheel and tire assembly run out, it is important to have it diagnosed and repaired by a qualified mechanic as soon as possible.