COATS 1001 & 1001SC Balancer - Manual (Page 21)

COATS 1001 Wheel Balancer • 15
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
components.
5. Wheels not correctly centered due to damaged
hub, damaged or worn center hole, worn bolt circle
holes, or imprecise original design. Check wheel run
out before balance spin and on the vehicle after mount-
ing.
6. Sensitive suspensions. Use FINE BALANCE (See
page 10).
Complaint: Balancer uses too many weights or sev-
eral spins to balance.
Remedy: Recheck rim dimensions entered. Position
the weights exactly top dead center when green posi-
tion lights are on.
Complaint: Weight or position readings fluctuate.
Remedy: Check cone/hubnut for slippage. Check that
the balancer is resting firmly on three mounting points,
floor is flat and stable, and that no tools or weights are
between balancer and floor.
Calibration
Calibration Check Procedure
The calibration check procedure can be performed by
the operator to ensure that the balancer is operating
correctly and is properly calibrated. The only purpose of
calibration is to trim the balancer to yield single-spin
balancing.
Note: If the balancer is set up to display weights in
grams instead of ounces, then observe the parenthe-
sis (0.00 gram) values in the CALIBRATION CHECK
PROCEDURE and the CALIBRATION ADJUSTMENT
MODE.
Throughout the calibration, check procedure, keep
the start button depressed during each cycle. This is
the FINE BALANCE mode which allows the balancer to
read in .01 ounce (1 gram) increments.
1. Mount a standard domestic 14" x 6" wheel with an
F78-14 or 206/75-14 tire using the proper back cone.
Ensure that the wheel is not bent or misaligned and
that the center hole is free of nicks and burrs.
2. Program the distance, rim width, and rim diame-
ter information into the balancer by setting the knobs
on the front panel.
3. Balance the wheel using FINE BALANCE until
0.00 weight readings appear on INNER and OUTER
displays while holding down the start button during the
entire cycle.
4. After getting 0.00 to appear while holding the
start button, change the Rim Diameter adjustment to
read 10.5. If any weight reading appears, repeat step 3.
5. Return the Rim Diameter adjustment to 14.
6. Install a 4 ounce (113 gram) test weight on the
outer rim.
7. Spin. The new weight reading should be 3.80 to
4.20 ounce (108 gram to 119 gram). Rotate the wheel
so that the central position lights on the outer position
indicator come on. The test weight should be directly
across (at 6 o’clock).
Weight readings on the inner display should be 0.20
ounce (6 gram) or less. (This results from interference
between the two balancing planes.)
8. Repeat steps 6 and 7 with the 4 ounce (113 gram)
test weight on the inner rim.
9. If the balancer fails to yield the results required by
this procedure, perform the CALIBRATION ADJUST-
MENT PROCEDURE.
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