Chery A15. Manual — part 215

attached on each side of each wheel. Avoid heavy impact on weights during

assembling, and replace the heavily impacted weights. Replaced weights are not

reusable.

(5). When installing wheel and tire assembly, first fix wheel bolts on wheel hub and

pretighten with hand, then tighten them with a special tool in a diagonal process,

tightening torque 110±10N.m. Impact wrench is not allowed to avoid overtightness

or undertightness. Lubrication of wheel bolts is prohibited. (For newly installed wheel

and tire assembly, tighten wheel bolts after the first 100km to ensure fastening torque.

Wheel bolt tightening torque inspection is one of daily maintenance items.)

(6). Tighten the set nuts in a diagonal process with the similar tightening torque,

which shall allow the free rotation of wheels. Wheels shall be placed on the ground

when finally tightening the nuts.

(7). Fix or place decorating cover as required. Lock decorating cover shall be fixed by

tapping with hands or knocking with a rubber tool.

II. Common Tire Faults

1. Proper Use of Tires

Tires are important components of wheel assemblies. Attention shall be paid to

following items:

(1). One vehicle shall be equipped with tires of the same model made by the same

manufacturer.

(2). Tires of other unspecified models are not allowed.

(3). All tires shall bear the same worn condition. To compensate and relieve the

uneven wear among tires, they shall be interchanged periodically in addition to

routine inspection and calibration of wheel alignment parameters. Interchange scheme

is shown in the figure. Specific interchange shceme may be adopted according to

actual wear condition. Recommended interchange mileage is 5000-8000km

2. Common Tire Faults and Diagnosis

(1). Lopsided wear

Lopsided wear refers to burr formed on tire edge, which indicates heavier wear than

other positions. Lopsided wear is theorically caused by rolling of tire with an extreme

side slip angle.

Possible causes: frequent high speed turning, improper toe-in and camber angle

adjustment, constant running on arch or snake-like roads.

Solution: adjust front wheel alignment angle and toe-in.

(2). Centered wear

Centered wear refers to abnormal wear in middle part of tire tread. Centered wear is

theatrically caused by a tire diameter elongation at central tread that is larger than

elongation at tire shoulder.

Possible cause: too high tire pressure.

Solution: regulate tire pressure to be within specified limits.

(3). Sawtooth wear

Sawtooth wear is the step-like wear of tire tread. This is caused by the uneven

deformation of road-touching part of tire.

Possible Cause: incompliant toe-in and camber angle.

Solution: adjust toe-in and camber angle to be within specified limits; check and

regulate tire inflation pressure to be within specified limits.

(4). Partial heavy wear in early use

Heavy wear in early use refers to the heavy wear of tire tread caused by wheel lockup

during emergency braking.

Possible causes: vehicle speed, road condition and wheel load, braking severity during

emergency braking.

Solution: avoid emergency braking by taking preventive measures.

(5). Scratch or crack on side wall

This is mainly caused by sharp objects on road surface or rubble, nail, sheet metal

embedded in tire grooves.

(6). Undue wear found at about half cycle of tire or wear at different positions on tire

shoulder

The possible causes may include unbalanced rotating part, off-centered tire, worn and

loose bearing, off-centered or bent wheel hub or steering knuckle, etc.

3. Troubleshooting

Problem Possible

Cause

Solution

Overwear

Improper tire pressure

Adjust

Noise

Improper tire pressure

Deteriorated tire

Adjust

Replace

Road surface noise or

vehicle body vibration

Insufficient tire pressure

Unbalanced tires

Wheel rim or tire deformation

Uneven wear

Adjust

Adjust

Repair or replace

--

Vertical vibration of

steering wheel

Excessive deflection of tire

and wheel rim

Loose wheel nut

Unbalanced tires

Broken or worn

engine bearing pad

Broken or worn gearbox

bracket rubber

Replace

Tighten

Adjust

Replace

Replace

Circular vibration of

steering wheel

Excessive deflection of tire

and wheel rim

Loose wheel nut

Unbalanced tires

Uneven wear

Insufficient tire pressure

Broken or worn bearing of

front wheel

Steering system fault

Suspension system fault

Replace

Tighten

Adjust

--

Adjust

Replace

--

--

Side deflection of

steering wheel

Improper tire pressure

Overwear or uneven wear of

tires

Steering system fault

Brake system fault

Suspension system fault

Adjust

--

--

--

--

Continued

Unstable driving

Inconsistent tire pressures

Wheel rim or tire deformation

Loose wheel nut

Steering system fault

Suspension system fault

Adjust

Repair or replace

Tighten

--

--

Side deflection of brake

Inconsistent tire pressures

Brake system fault

Adjust

--

Heavy steering

Insufficient tire pressure

Steering system fault

Suspension system fault

Adjust

--

--

Poor return of

steering wheel

Insufficient tire pressure

Steering system fault

Suspension system fault

Adjust

--

--

III. Checking Transmission Bar Connection of Steering System

Check transmission bar connection of steering system to see if there is any loose

connection or deformation.

IV. Checking Connection Balls and Gum Covers of Front/Rear

Suspension

V. Checking Normal Operation of Shock Absorbers

1. Check shock absorber for oil leakage

2. Check lining for wear

3. Bounce front and rear part of vehicle to check if the vehicle body is over softened.

Section Two: Rear Wheel Alignment

Four-wheel aligner using axis of thrust alignment is recommended for this chassis

model.