WHEEL AND TIRES DIAGNOSIS/TESTING
id021200800900
Inspection/Verification
1. Be sure to follow the warnings when carrying out inspection and verification.
Road test
1. Verify the customer concern by carrying out a road test on a smooth road. If any vibrations are apparent, diagnose the area where is attributed to NVH.
2. To maximize tire performance, inspect for signs of suspension alignment, or damaged steering incorrect inflation and uneven wear. If there is any, indicate a need for balancing, rotation, or a suspension alignment.
3. Correct tire pressure and driving techniques have an important influence on tire life. Heavy cornering, excessively rapid acceleration and unnecessary sharp braking increase tire wear.
4. Replacement tires should follow the recommended:
5. Use of any other tire size or type may seriously affect:
6. Wheels need to be replaced when:
7. Wheel and tire assemblies are attached by five wheel nuts.
It is mandatory to use only the tire sizes recommended on the tire chart attached to the vehicle. Larger or smaller tires can damage the vehicle, affect road test driveability, and require changing the speedometer calibration. Make sure wheel size and offsets match those recommended for the tire in use.
Match mounting tires
1. Match mounting is a technique used to reduce radial runout. Excessive runout is a source of vibration, shimmy and poor handling concerns. Use the following steps to reduce radial runout:
Tire lead diagnosis
1. Lead is the deviation of the vehicle from a straight path on a level road with no pressure on the steering wheel. Lead can be caused by:
2. If defective tires are suspected in a lead condition, use the following steps to determine the defective tire:
Symptom Troubleshooting Chart
1. Verify the symptom, and conduct corresponding diagnosis.
Troubleshooting Item |
Possible Cause |
No. |
---|---|---|
Tires show excess wear on edge of tread.
|
• Underinflated tires
• Vehicle overloaded
• Incorrect wheel alignment
• High-speed cornering
• Incorrect tire rotation intervals
|
1
|
Tires show excess wear in center of tread.
|
• Overinflated tires
|
2
|
Other excessive/uneven tire wear problems (Except edge and center of tread)
|
• Improper tire pressure
• Worn or damaged suspension components
• Incorrect tire/wheel usage
• Damaged, loose, or leaking shock absorbers
• Incorrect wheel alignment
• Wheel and tire assembly out of balance
• Excessive lateral or radial runout of wheel or tire
• Tires need rotating
|
3
|
Wheel mounting is difficult.
|
• Incorrect application or hub bolts and wheel nuts
• Corroded, worn or damaged new parts
|
4
|
Wobble or shimmy
|
• Worn or damaged wheel bearings
• Loose or damaged suspension components
• Bent or damaged wheel
• Wheel and tire assembly out of balance
• Damaged tire
• Loose wheel nuts
|
5
|
Vehicle vibrations
|
• Driveline.
• Wheel and tire assembly out of balance.
|
6
|
High-speed shake
|
• Wheel hub face/pilot/bolt circle runout.
• Wheel and tire assembly out of balance.
• Damaged or worn wheel bearings.
• Damaged or worn suspension/steering linkage.
• Driveline.
• Brake discs/imbalance.
|
7
|
Damaged wheel nuts
|
• Loose wheel assembly.
• Overtightened wheel nuts.
|
8
|
Frozen wheel nuts
|
• Corrosion or galling.
• Overloading.
|
9
|
No.1 Tires Show Excess Wear On Edge Of Tread.
Diagnostic procedure
STEP |
INSPECTION |
ACTION |
|
---|---|---|---|
1
|
Inspect the tire pressure.
Is each tire pressure correct?
|
Yes
|
Go to the next step.
|
No
|
Adjust the tire pressure.
|
||
2
|
Inspect for vehicle overloading.
Is the vehicle under normal load?
|
Yes
|
Go to the next step.
|
No
|
Notify the customer of overload condition.
|
||
3
|
Inspect the wheel alignment.
Is the wheel alignment correct?
|
Yes
|
Go to the next step.
|
No
|
Set the alignment to specification.
(See FRONT WHEEL ALIGNMENT.)
(See REAR WHEEL ALIGNMENT.)
|
||
4
|
Inspect for high-speed cornering.
Is there no indication of high-speed cornering?
|
Yes
|
Go to the next step.
|
No
|
Return vehicle — Notify the customer of cause of condition.
|
||
5
|
Inspect the tire rotation interval.
Is the tire rotation interval correct?
|
Yes
|
Vehicle is normal.
|
No
|
Advise the customer of condition. Rotate tires.
|
No.2 Tires Show Excess Wear In Center Of Tread.
Diagnostic procedure
STEP |
INSPECTION |
ACTION |
|
---|---|---|---|
1
|
Inspect tire pressure.
Is the tire pressure correct?
|
Yes
|
Vehicle is normal.
|
No
|
Inspect the tire pressure.
|
No.3 Other Excessive (Except Edge and Center)/uneven Tire
Diagnostic procedure
STEP |
INSPECTION |
ACTION |
|
---|---|---|---|
1
|
Inspect the tire pressure.
Is the tire pressure correct?
|
Yes
|
Go to the next step.
|
No
|
Adjust the tire pressure.
|
||
2
|
Inspect wear and damage in the suspension components.
Are the suspension components normal?
|
Yes
|
Go to the next step.
|
No
|
Inspect according to suspension system diagnosis/ test.
|
||
3
|
Inspect for correct tire and wheel usage.
Is the tire and wheel usage correct?
|
Yes
|
Go to the next step.
|
No
|
Install the correct tire and wheel combination.
|
||
4
|
Inspect the shock absorbers.
Are the shock absorbers normal?
|
Yes
|
Go to the next step.
|
No
|
Tighten or install new shock absorbers.
|
||
5
|
Inspect the wheel alignment.
Is the wheel alignment correct?
|
Yes
|
Go to the next step.
|
No
|
Set the wheel alignment to the specifications.
(See FRONT WHEEL ALIGNMENT.)
(See REAR WHEEL ALIGNMENT.)
|
||
6
|
Inspect tire and wheel balance.
Is the tire and wheel balance correct?
|
Yes
|
Go to the next step.
|
No
|
Balance the wheel and tire of balance. assembly.
|
||
7
|
Inspect tire and wheel runout.
Is there any tire and wheel lateral or radial runout?
|
Yes
|
Advise the customer of the condition. Rotate the tires.
|
No
|
Vehicle is normal.
|
No.4 Wheel Mounting Is Difficult
Diagnostic procedure
STEP |
INSPECTION |
ACTION |
|
---|---|---|---|
1
|
Inspect hub bolts and wheel nuts.
Are the hub bolts and wheel nuts correctly applied and matched?
|
Yes
|
Go to the next step.
|
No
|
Replace with correct parts.
|
||
2
|
Inspect hub bolts and wheel nuts.
Are the hub bolts and wheel nuts normal?
|
Yes
|
The vehicle is normal.
|
No
|
Repair and replace hub bolt and wheel nut, as necessary.
|
No.5 Wobble or Shimmy
Diagnostic procedure
STEP |
INSPECTION |
ACTION |
|
---|---|---|---|
1
|
Inspect wheel bearings.
Are the wheel bearings free of damage?
|
Yes
|
Go to the next step.
|
No
|
Install new wheel bearings.
|
||
2
|
Inspect any loose or damaged suspension components.
Are the suspension components correct?
|
Yes
|
Go to the next step.
|
No
|
Repair or replace suspension components, as necessary.
|
||
3
|
Inspect the wheels.
Are the wheels free of damage or bending?
|
Yes
|
Go to the next step.
|
No
|
Replace wheels, as necessary.
|
||
4
|
Inspect wheel and tire balance.
Is the wheel and tire balance correct?
|
Yes
|
Go to the next step.
|
No
|
Balance the wheel and tire assembly.
|
||
5
|
Inspect the tires.
Are the tires free of damage?
|
Yes
|
Go to the next step.
|
No
|
Replace tires, as necessary.
|
||
6
|
Inspect wheel nuts.
Are the wheel nuts tightened securely?
|
Yes
|
Vehicle is normal.
|
No
|
Tighten to specification.
|
No.6 Vehicle Vibrations
Diagnostic procedure
STEP |
INSPECTION |
ACTION |
|
---|---|---|---|
1
|
Inspect the drive line.
Is the drive line normal?
|
Yes
|
Go to the next step.
|
No
|
Considered as a NVH concern. Repair or replace area where attributed to NVH.
|
||
2
|
Inspect wheel and tire balance.
Is the wheel and tire balance correct?
|
Yes
|
Vehicle is normal.
|
No
|
Balance the wheel and tire assembly.
|
No.7 High Speed Shake
1. This is considered as a concern due to NVH. Identify NVH cause, and repair or replace.
No.8 Damaged Wheel Nuts
Diagnostic procedure
STEP |
INSPECTION |
ACTION |
|
---|---|---|---|
1
|
Inspect the wheel nuts.
Is the wheel nut free of looseness?
|
Yes
|
Go to the next step.
|
No
|
Replace wheel.
|
||
2
|
Inspect the wheel nuts.
Overtightened wheel nuts?
|
Yes
|
Vehicle is normal.
|
No
|
Remove the wheel nuts. Inspect for damage. Install new components as necessary.
|
No.9 Frozen Wheel Nuts
Diagnostic procedure
STEP |
INSPECTION |
ACTION |
|
---|---|---|---|
1
|
Inspect for frozen wheel nuts.
Are the wheel nuts normal?
|
Yes
|
Go to the next step.
|
No
|
If the corrosion is slight, brush away the corrosion with a wire brush. If the corrosion is excessive, install new wheel studs and wheel nuts. If the condition persists, lubricate the first three threads of each wheel stud with a graphite-based lubricant
|
||
2
|
Inspect vehicle load condition.
Is load condition normal?
|
Yes
|
Vehicle is normal.
|
No
|
Adjust load volume, as necessary.
|