81
Ver. 0
4
-2015
Use and Maintenance Manual
ENGLISH
Diagnostics
9. DIAGNOSTICS
9.1 INCONSISTENT UNBALANCE READINGS
In some cases, when a wheel that has just been balanced is repositioned on the balancer, the machine can
detect an unbalance.
This is not a machine problem but is due to faulty mounting of the wheel on the flange. In other words,
when mounting the wheel after initial balancing, it has taken another position with respect to the balancer
shaft axis.
If the wheel has been mounted on the flange with screws, the screws may not have been tightened correctly
(criss-cross sequence) or the tolerances of the holes drilled in the wheel may be too large. Small errors,
up to 10 grams (0.4 oz), are to be considered normal in wheels locked with the relative cone: The error is
normally greater for wheels locked with screws or studs.
If, after balancing, the wheel is still unbalanced when refitted on the vehicle, this could be due to an un-
balanced brake drum or, very often, the tolerances of the holes drilled in the rim and drum are too large.
In this case, balancing should be performed using a balancer with the wheel mounted on the vehicle.
