Geely Emgrand X7. Manual part — 372

4.4.4.5 Wheel vibration diagnosis

1.

Dynamic balance of tire

The dynamic balance of the tire is the procedure which is most easily to be checked; and if the vehicle vibrates at
high speed, the dynamic balance should be firstly carried out. Firstly, carry out double-faced dynamic balance
under the vehicle to correct the imbalance of the tire and the wheel assembly. On-board final balancing can
correct the imbalance of the brake drum, brake disc or hub cap. If the balancing operation fails to eliminate the
vibration at high speed, or if the vibration occurs at low speed, the vibration is likely to be caused by jump.

2. Runout

The connection mode of the tire and the wheel or the wheel and the vehicle may result in jump. In order to probe
the possibility of the wheel run-out, refer to the wheel run-out diagnosis table as follows:

Warning: Please carry out road test of vehicle under the safety condition and comply with all traffic
regulations. Do not attempt any operation that could jeopardize vehicle control. If contrary to the above
safety instruction, result in serious injury accident and damage to the vehicle.

1

Carry out road test for the vehicle to confirm the fault phenomenon as well as the vibration described
by the customer belongs to fault?

2

Determine the vibration speed.Is the speed more than 65 km/h when vibrating?

3

Perform the tire dynamic balance under the vehicle and road test of vehicle to confirm the existence of
the fault?

4

Perform the final balance in the vehicle and road test of vehicle to confirm the existence of the fault?

5

Check whether the wheel's free end face and the radial run-out (standard valve: 1.0mm/0.0394in)
accord with the specified value?

Replace front wheel bearing

Go to step 5

Troubleshooting

Yes

No

Yes

No

Yes

No

Troubleshooting

Yes

No

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6

Check whether the vehicle drive system is unbalanced?

Thoroughly check the drive axle and constant velocity universal joint.

7

Inspect the hub flange run-out (standard value: 0.26mm/0.0102in) as well as whether the run-out
accords with the specified value?

8

Dismantle the wheel assembly and tires from the assembly to measure the run-out of the wheel.

Radial run-out

0.5mm(0.02in)

Aluminum wheels

End-face runout

0.5mm(0.02in)

Aluminum wheel assembly

Free radius run-out

1.5mm(0.06in)

Is wheel run-out as specified?

9

Replace the tire

10

Confirm whether the fault is removed.

Replace the part damaged.

Refer 4.2.7.9 replacement of Front Hub to
replace the hub assembly.

Go to step 8

Refer to 4.4.5.1 Replacement of wheels to
replace the wheels.

Yes

No

Yes

No

Yes

No

Yes

No

Next

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4.4.4.6 Wheel runout inspection

1

2

3

3

NL04-1013b

The wheel run-out can be measured by a dial gauge in and out of the vehicle; however, the mounting surface must
be correct; it can be measured with tire during measuring; the radial and end face run-out are measured inside
and outside the rim flange; a dial indicator is fixed next to the wheel and tire assembly; slowly rotate the wheel in
a circle and record the reading of the dial gauge; if the measuring value exceeds the following specification, and
the wheel balance can also not eliminate the vibration, replace the wheel.

Aluminum wheels

Radial run-out: 0.5mm (0.02in)

End-face runout: 0.5mm (0.02in)

Aluminum wheel assembly

Free radius run-out: 1.5 mm (0.06 in)

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4.4.4.7 Wheel abnormal worn diagnosis

There are many reasons for abnormal tire and premature wear, including wrong inflation pressure, irregular
rotation, poor driving habits or incorrect wheel alignment. If needing to readjust the wheel positioning due to tire
wear, the toe-in must be regulated close to zero as much as possible so long as the specification allows.

If the following situations incur, the tires must be converted.

A. Front tire wear is different the rear tire wear.

B. The wear of the front left tire is different from that of the front right tire.

C. The wear of the rear left tire is different from that of the rear right tire.

If the following situations incur, the wheel positioning must be checked.

A. The wear of the front left tire is different from that of the front right tire.

B. The tread of either front wheel tire is unevenly worn.

C. A feather-shaped scratch exists on one side of the pattern rib or pattern block on the tread of the front tire.

The several typical tire wear conditions are as follows:

1. Eccentric

abrasion

NL04-1014b

Cause

A. Malfunctions of such movable parts as axles, bearings, etc.

B. Brake

system

C. Emergency startup and emergency brake

D. The gravity centers on the wheel are unevenly distributed.

E. The tire does not match with the size of the hub.

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