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comparing data.
Do not check repeatability using ALU mode because it is “hyper-sensitive” in comparison to clip-on weight placement. In ALU mode
the diameters are smaller and the planes are closer together compared to standard clip weight balance, therefore any change in re-centering
will be amplified compared to when clip-on weight planes are dialed-in.
For example, a wheel that needs 0.25 or 0.50 oz. weights in ALU mode may show zeroes in clip-on weight mode. You can also get cases
where dynamic imbalance on standard is small, such as 1 oz., and it jumps to 4 or more oz. in ALU if the planes are close enough together.
All balancers will do this….and that’s why most balancers have such a hard time hitting zero on the first spin.
If the imbalance amounts change and the readings from the first sample data and the second sample data are NOT the same for 0, 90,
180, and 270 degrees, the assembly is not being mounted correctly. Refer to “
Mounting the Wheel on the Spindle Shaft”
for proper
mounting techniques.
If ALL readings change, BUT the readings from the first sample data and the second sample data are the same for 0, 90, 180, and 270
degrees, the hub/shaft assembly is out of position. Use a dial indicator to check for run out on the hub face and on the shaft. Run out on
the hub face should not exceed 0.0015”. Run out on the shaft should not exceed 0.0015”. If run out exceeds these limits, remove the
threaded hub/shaft assembly and inspect for any debris or nicks on the tapered mounting surfaces only, spindle and hub assembly must be
replaced.
BALANCER MOUNTING METHODS
MOUNTING THE WHEEL ON THE VEHICLE
Since today’s vehicles are more sensitive to road feel, it is critical to be aware of how the wheel mounts on the vehicle. Acceptable ride
quality depends on accurately mounting the wheel on the vehicle hub. Step torqueing lug nuts in a star pattern should be followed on every
installation.
If the wheel is not placed on the vehicle using the same centerline that was used on the balancer, the wheel balance, run out, and force
variation will not be duplicated.
Improper wheel centering is a huge problem when the hub bore of the wheel does not ‘slip fit’ onto the hub of the vehicle. Extra
caution should be used when mounting these types of wheels after servicing on the balancer. This is especially prevalent on lower cost
aftermarket wheels. In many cases, a tire and/or wheel is blamed for creating unacceptable vibration when in fact it was merely mounted
on the vehicle improperly.
MOUNTING THE WHEEL ON THE SPINDLE SHAFT
Since today’s vehicle designs are lighter and more sensitive to road feel, it is critical to achieve the best balance. Proper balance requires
that the tire/wheel assembly be centered on the balancer. Most balancers will balance the tire/wheel assembly to zero, even with the
tire/wheel assembly mounted off center. The main objective of the balancer operator is to center the wheel on the balancer using the best
available method. Mounting the wheel off-centre on the balancer creates incorrect measurements of imbalance and run out conditions.
MOUNTING WHEELS WITH CONES
The majority of wheels are mounted with a cone to center them on the balancer’s shaft. Cones are manufactured with different tapers.
