Tools Required
J 38792-A Electronic Vibration
Analyzer (EVA) 2
If after following the tire and wheel vibration diagnostic process,
some amount of tire and wheel vibration is still evident, an on-vehicle high-speed
spin balancer may be used to perform an on-vehicle balance in an attempt to
finish balance the tire and wheel assemblies, wheel hubs, brake rotors, and
wheel trim, if equipped, simultaneously. On-vehicle balancing can also compensate
for minor amounts of residual runout encountered as a result of mounting
the tire and wheel assembly on the vehicle, as opposed to the balance which
was achieved on the off-vehicle balancer.
In order to perform an on-vehicle balancing procedure, carefully follow
the on-vehicle balancer manufacturer's specific operating instructions and
carefully consider the following information before proceeding:
| • | Vehicles equipped with low profile, wide tread path, high performance
tires and wheels are susceptible to small amounts of dynamic imbalance. |
| • | When performing an on-vehicle balance, great care must be taken
when placing the wheel balance weights on the wheels. If the wheel balance
weights are not placed accurately, they can actually induce dynamic imbalance
and thus increase the severity of the vibration. |
| • | Inspect the vehicle wheel bearings to ensure that they are in
good condition. |
| • | Thoroughly inspect all on-vehicle balancing equipment and ensure
that it is fully within the manufacturer's recommended specifications. |
| • | Do not remove the off-vehicle balance weights. The purpose of
on-vehicle balance is to fine tune the assembly balance already achieved
off-vehicle, not to start over. |
| • | Leave all wheel trim installed whenever possible. |
| • | If the on-vehicle balancer calls for more than 28 g (1 oz)
of additional weight, split the weight between the inboard and outboard
flanges of the wheel, so as not to upset the dynamic balance of the assembly
achieved in the off-vehicle balance. For wheel balance weight information,
refer to
Tire and Wheel Assembly Balancing - Off Vehicle
. |
| • | If available, tape-off an area on top of the fenders and the quarter
panels, then place the vibration sensor of the J 38792-A
, Electronic Vibration Analyzer (EVA) 2, on the fender
or quarter panel above the specific tire and wheel assembly while it is
being on-vehicle balanced. |
| | The J 38792-A
will provide a visual indication of the amplitude of the
vibration, and the effect that the on-vehicle balance has on it. |
