When you consider that only 1/4-ounce of wheel imbalance can produce a noticeable vibration on a vehicle, it’s easy to understand why it’s so important to have a wheel balancer that is both accurate and easy to use. Many balancers in today’s marketplace are capable of balancing a wheel to within a few hundredths of an ounce, and provide various features to help the technician position the weights properly.
Accuracy, when it comes to tire balancing, is also very important to your customers. Proper balance is essential to maintaining proper traction, providing a smooth ride and realizing maximum tire life.
A wheel balancer can be one of the most profitable pieces of equipment in a service shop. A balancer generates revenue every time you sell a balancing job following an alignment, tire repair, tire rotation or when it is used to help solve a vibration problem a customer is experiencing. Even if you offer “free” balancing with new tires, your customers will appreciate the value of balancing and making sure their vehicles are properly balanced before they leave your shop, and this will limit the number of comebacks your shop experiences.
Understanding Balance
If one area of a given wheel is heavier than the rest of the assembly, it will cause the wheel to vibrate when it spins. A vibration will become progressively worse as the vehicle’s speed increases. The amount of vibration and when it first becomes evident varies from vehicle to vehicle. Some of the factors that come into play include:
The size and weight of the wheels;
The sensitivity of the steering and suspension;
The amount of imbalance in the wheel; and
The type of vehicle. The same weight imbalance on an SUV will feel different on a smaller compact car.
Losing Its Balance
One of the most common reasons a wheel loses its balance is simply tire wear. As a tire wears, it loses rubber and weight. Since tires rarely wear evenly, the wheel balance gradually goes bad.
Another factor that can result in the loss of balance includes ABS braking. When an ABS system activates, it can exhort such force on a tire that it’s position on the rim is changed. This can instantly change the original balance. Any damage a tire may receive, whether it is from scraping against a curb or hitting a large pothole, can also change the distribution of weight, thus affecting balance.
Shopping for a Balancer
When shopping for a new balancer, it’s important to invest in a good piece of equipment that meets the needs of your shop. Computerized spin balancers can produce accurate results in very little time. Look for a balancer with a digital readout, one that has display screens that show the operator where to place the weights on the wheel.
While in the past, wheel sizes and widths had to be entered manually, many of today’s machines take these measurements for the technician and automatically enter the numbers into the equipment’s computer. This feature is very helpful because the less the technician has to do manually, the lower the chances are for mistakes being made that could result in comebacks and unhappy customers. Remember, the best machine is no better than the person operating it. This is why making sure your technicians receive the proper training is so critical.
If a technician isn’t properly trained to use these special features, chances are he will turn off the features or ignore the data that is provided.
The technician also must be able to understand the theory behind balancing, be able to properly mount a wheel on the balancer and be able to select the right type of weights for the rim.
Proper Mounting
Balancing a wheel may seem like a simple operation — the technician puts the wheel on the spindle, tightens the wingnut, closes the hood (or spins the wheel by hand) and steps back and allows the balancer to calculate what weights are needed and where they should be placed. But blindly operating in this manner could create a comeback.
One equipment manufacturer maintains that approximately 60% of balance problems are due to mounting errors. This number highlights how critical it is to make sure your technicians are able to properly mount a wheel on the balancer.
When taking the wheels off a vehicle, make note as to if they are hub-centric or lug-centric. How the wheels mount on the vehicle will determine how they mount of the balancer.
A hub-centric wheel, which is the most common type of OE mounting method, will stay in the same position, even if you try to move it side to side or up and down, when the lugs are removed. These wheels are the least likely to cause mounting problems when they are put back on the vehicle.
Lug-centric wheels are very susceptible to mounting errors. Lug-centric wheels center the studs and conical seats between the lug and wheel or by the shanks on the lugs. When mounting lug-centric wheels onto a balancer, a flange plate with simulated wheel studs is used to hold the wheel of the shaft by the lug holes. The plate is designed so that when the wingnut or speednut is tightened down, each simulated stud on the plate will receive the identical torque. This ensures that the wheel is sitting absolutely vertical on the wheel with equal pressure in each lug hole.
Lug-centric wheels are commonly found on aftermarket wheels because the manufacturer only has to account for lug pattern, not diameter, so the wheels are able to fit multiple vehicles. Since a flange plate, which only touches the wheel in the lug holes, is used to mount these wheels onto the balancer, there is no danger of scratching aftermarket alloy wheels.
Purchasing Equipment
Don’t allow yourself to fall into the trap of purchasing a piece of equipment based on just the initial price. In the long term, cost of ownership and possible premature replacement can cost more than buying a quality piece of equipment in the first place.
When you invest in a quality wheel balancer, you also are purchasing the support that goes along with it. Some manufacturers spend a great deal of money on local representation, distribution networks for parts and training centers.
Support and training are essential services to making a piece of equipment profitable and capable of delivering its full potential. Always ask if the manufacturer offers field training or training at regional centers. Even the best machine becomes useless if it can’t be serviced and supported by the manufacturer or the distributor that sold it to you.
