COATS 6401 Computer Truck Wheel Balancer - Manual (Page 22)

Special Problems
Customers will occasionally complain of vibration on the car
after balancing. Some possible causes are listed below:
1. Beads improperly seated. Check bead seating and inflation
pressure before balancing spin.
2. Stiffness variations in radial belts.
3. Tire out of round; wheel out of round, bent, or not running
true. Visually check runout of wheel and tire during balance spin.
Re-check mounting. Replace wheel or tire if necessary.
4. Suspension wear, misalignment, or loose vehicle compo-
nents.
5. Wheels not correctly centered due to damaged hub, dam-
aged or worn center hole, worn bolt circle holes, or imprecise
original design. Check wheel run out before balance spin and on
the vehicle after mounting.
6. Sensitive suspensions. Set the balancer to a non-Round Off
mode (See page 6).
Complaint: Balancer uses too many weights or several spins
to balance.
Remedy: Recheck rim dimensions entered. Position the
weights exactly top dead center when red position lights are on.
Complaint: Weight or position readings fluctuate.
Remedy: Check cone/hubnut for slippage. Check the balancer
is resting firmly on three mounting points, floor is flat and sta-
ble, and that no tools or weights are between balancer and floor.
Direct Drive
16 • COATS 6401 Truck Wheel Balancer