c.Inspect the tire wear pattern.
● Do the tires have an abnormal wear pattern ?
→ YES
Correct the condition that caused the abnormal wear. Install new tire(s).
Test the system for normal operation.
→ NO
Go to
TIRE ROTATION DIAGNOSIS a.Spin the tires slowly and watch for signs of lateral runout.
b. Spin the tires slowly and watch for signs of radial runout.
● Are there signs of visual runout ?
→ YES
Go to
→ NO
Check the wheel and tire balance.
Correct as necessary. Test the system for normal operation.
RADIAL RUNOUT CHECK ON THE TIRE Measure the radial runout of the wheel and tire assembly. A typical
specification for total radial runout is 1.15mm (0.059 inch).
● Is the radial runout within specifications ?
→ YES
Go to C8.
→ NO
Go to C6.
RADIAL RUNOUT CHECK ON THE WHEEL Measure the radial runout of the wheel. A typical specification for total radial
runout is 1.14mm (0.045 inch.).
● Is the radial runout within specifications ?
→ YES
Install a new tire. Test the system for normal operation.
→ NO
Go to C7.
CHECK THE HUB/BRAKE DISC OR DRUM PILOT RUNOUT OR BOLT CIRCLE RUNOUT Measure the pilot or bolt circle runout. A typical specification for radial
runout is :
● pilot runout - less than 0.15mm (0.006 inch.)
● bolt circle runout - less than 0.38 mm (0.015 inch.)
● Is the radial runout within specification ?
→ YES
Install a new wheel. Test the system for normal operation.
→ NO
Repair or Install new components as necessary.
LATERAL RUNOUT CHECK ON THE TIRE Measure the lateral runout of the wheel and tire assembly. A typical
specification for total lateral runout is 2.5mm (0.098 inch).
specification for total lateral runout is 2.5mm (0.098 inch).
● Is the lateral runout within specifications ?
→ YES
Wheel and tires are OK. Conduct diagnosis on other suspect systems.
→ NO
Go to C9.
LATERAL RUNOUT CHECK ON THE WHEEL Measure the lateral runout of the wheel. A typical specification for total
radial runout is 1.2mm (0.047 inch.)
● Is the lateral runout within specifications ?
→ YES
Install a new tire. Test the system for normal operation.
→ NO
Go to C10.
CHECK THE FLANGE FACE LATERAL RUNOUT Measure the flange face lateral runout. A typical specification for lateral
runout is :
● hub/brake disc - less than 0.13mm (0.005 inch)
● Is the lateral runout within specifications ?
→ YES
Install a new wheel. Test the system for normal operation.
→ NO
Repair or Install new components as necessary.
DETAILED TEST D : CONDITIONS DETAILS/RESULTS/ACTIONS
CHECK FOR FRONT WHEEL BEARING ROUGHNESS
a.Raise and support the front end of the vehicle so that the front wheel
and tire assemblies can spin.
See GI group - lift support point.
b. Spin the front tires by hand.
● Do the wheel bearings feel rough ?
→ YES
Inspect the wheel bearings. Repair as necessary. Test the system for
normal operation.
→ NO
Go to
CHECK THE END PLAY OF THE FRONT WHEEL BEARINGS Check the end play of the front wheel bearings.
● Is the end play OK ?
→ YES
Go to D3.
Go toD3.
→ NO
Adjust or Repair as necessary. Test the system for normal operation.
MEASURE THE LATERAL RUNOUT AND THE RADIAL RUNOUT OF THE FRONT WHEELS ON THE VEHICLE Measure the lateral runout and the radial runout of the front wheels on the
vehicle. Go to detailed test C.
● Are the measurements within specifications ?
→ YES
Go to D4.
→ NO
Install new wheels as necessary and Balance the assembly. Test the
system for normal operation.
MEASURE THE LATERAL RUNOUT OF THE FRONT TIRES ON THE VEHICLE Measure the lateral runout of the front tires on the vehicle. Go to detailed
test C.
● Is the runout within specifications ?
→ YES
Go to D5.
→ NO
Install new tires as necessary and Balance the assembly. Test the system
for normal operation.
MEASURE THE RADIAL RUNOUT OF THE FRONT TIRES ON THE VEHICLE Measure the radial runout of the front tires on the vehicle. Go to detailed
test C.
● Is the runout within specifications ?
→ YES
Balance the front wheel and tire assemblies. If any tire cannot be balanced,
Install a new tire. Test the system for normal operation.
→ NO
Go to D6.
MATCH MOUNT THE TIRE AND WHEEL ASSEMBLY Mark the high runout location on the tire and also on the wheel. Break the
assembly down and rotate the tire 180 degrees (halfway around) on the
wheel. Inflate the tire and measure the radial runout.
● Is the runout within specifications ?
→ YES
Balance the assembly. Test the system for normal operation.
→ NO
If the high spot is not within 101.6mm (4 inches) of the first high spot on
the tire, Go to D7.
MEASURE THE WHEEL FLANGE RUNOUT
Dismount the tire and mount the wheel on a wheel balancer. Measure the
runout on both wheel flanges. Go to detailed test C
● Is the runout within specifications ?
→ YES
Locate and Mark the low spot on the wheel. Install the tire, matching the
high spot on the tire with the low spot on the wheel. Balance the assembly.
Test the system for normal operation. If the condition persists, Go to D8.
→ NO
Install a new wheel. Check the runout on the new wheel. If the new wheel
is within limits, locate and Mark the low spot. Install the tire, matching the
high spot on the tire with the low spot on the wheel. Balance the assembly.
Test the system for normal operation. If the condition persists, Go to D8.
CHECK FOR VIBRATION FROM THE FRONT OF THE VEHICLE Spin the front wheel and tire assemblies with a wheel balancer while the
vehicle is raised on a hoist. Feel for vibration in the front fender or while
seated in the vehicle.
● Is the vibration present ?
→ YES
Substitute known good wheel and tire assemblies as necessary.
Test the system for normal operation.
→ NO
Check the driveline components. Test the system for normal operation.
DETAILED TEST E : DRIFT LEFT OR RIGHT CONDITIONS DETAILS/RESULTS/ACTIONS
CHECK THE TIRES Inspect the tires for excessive wear or damage.
● Are the tires excessively worn or damaged ?
→ YES
Install new tires.
→ NO
Go to E2.
CHECK THE STEERING LINKAGE
a.Raise and support the vehicle.
b. Check the steering components for indications of excessive wear or
damage.
See ST group - specification.
● Is there an indication of excessive wear or damage ?
→ YES
Repair or Install new components as necessary.
→ NO
Go to
CHECK THE VEHICLE ALIGNMENT a.Place the vehicle on an alignment rack.
→NO
Replace bent or damaged parts.
CHECK THE REAR SUSPENSION
a.Measure the vehicle wheel base for LH and RH.
b. Compare the measurements.
● Are the measurements the same ?
→ YES
If the ride is smooth, vehicle is OK.
If the ride is rough, Go to Detailed Test
→ NO
Inspect the rear suspension components for wear or damage.
Repair or Install new components as necessary.
DETAILED TEST H : ROUGH RIDE CONDITIONS DETAILS/RESULTS/ACTIONS
CHECK THE FRONT SHOCK ABSORBER
a.Raise support the vehicle.
b. Inspect the front shock absorber for oil leaks or damage.
● Are the tires excessively worn or damaged ?
→ YES
Install new front shock absorbers.
→ NO
Go to
CHECK THE REAR SHOCK ABSORBERS Inspect the rear shock absorbers for oil leaks or damage.
● Are the rear shock absorbers leaking ?
→ YES
Install new rear shock absorbers.
→ NO
The vehicle is OK. Go to TROUBLESHOOTING.
DETAILED TEST I : EXCESSIVE NOISE CONDITIONS DETAILS/RESULTS/ACTIONS
INSPECT THE SUSPENSION
a.Raise and support the vehicle.
b. Inspect the shock absorber mounting bolts.
● Are the mounting bolts loose or broken ?
→ YES
Tighten or Install new shock absorber mounting bolts.
→ NO
Go to
INSPECT THE SPRING AND TORSION BARS Inspect the springs and stabilizer bars for damage.
● Are the spring or stabilizer bars damaged ?
→ YES
Install new spring and/or stabilizer bars.
Install new spring and/or stabilizer bars.
→ NO
Go toI3.
INSPECT THE FRONT SUSPENSION Inspect the front suspension components for excessive wear or damage.
● Are the front suspension components worn or damaged ?
→ YES
Install new front suspension components.
→ NO
The vehicle is OK. Go to TROUBLESHOOTING.
DETAILED TEST J : INCORRECT TIRE WEAR CONDITIONS DETAILS/RESULTS/ACTIONS
INSPECT THE TIRES
a.Raise and support the vehicle.
b. Inspect the tires for uneven wear on the inner or outer shoulder.
● Is there uneven tire wear ?
→ YES
Align the vehicle. Install new tires if badly worn.
→ NO
Go to
UNEVEN TIRE WEAR Inspect the tires for a feathering pattern.
● Do the tires have a feathering pattern ?
→ YES
Align the vehicle. Install new tires if badly worn.
→ NO
Go to J3.
CHECK FOR CUPPED TIRE Inspect the tires for cupping or dishing.
● Are the tires cupped or dished ?
→ YES
Balance and Rotate the tires.
→ NO
The vehicle is OK. Go to TROUBLESHOOTING.
DETAILED TEST K : VIBRATION CONDITIONS DETAILS/RESULTS/ACTIONS
ROAD TEST Accelerate the vehicle to the speed at which the customer indicated the
vibration occured.
● Is the vibration present ?
→ YES
Go to K2.
→ NO
The vehicle is OK. Go to TROUBLESHOOTING.
INSPECT THE TIRES
a.Raise and support the vehicle with a frame contact hoist.
b. Inspect the tires for extreme wear or damage, cupping, or flat spots.
● Are the tires OK ?
→ YES
Go to
→ NO
Check the suspension components for misalignment, abnormal wear, or
damage that may have contributed to the tire wear.
Correct the suspension concerns and Install new tires.
INSPECT THE WHEEL BEARINGS Spin the tires by hand to check for wheel bearing rougness.
● Is the front wheel bearing OK ?
→ YES
Go to K4.
→ NO
Install new front wheel bearings as necessary.
See Ds group - front axle.
TIRE/WHEEL BALANCE Check the tire/wheel balance.
● Are the tires balanced ?
→ YES
Go to K5.
→ NO
Balance the tires and wheels as necessary.
MEASURE THE RUNOUTS For each wheel position measure, locate and mark the following items.
- High point of the tire/wheel assembly total radial runout
- High point of the wheel radial runout
- High point of the wheel lateral runout
● Are the runouts as specified ?
→ YES
Go to K7.
→ NO
Go to K6.
SUBSTITUTE THE WHEELS AND TIRE
a.Substitute a known good set of wheels and tires.
b. Perform a road test.
c. If the vehicle still exhibits a shake or vibration, note the vehicle speed
and/or engine rpm which it occurs.
● Is the vibration felt ?
→ YES
Engine/transmission imbalance.
See the specification of TR group, EM group, FL group and EC group.
→ NO
Install the original tire/wheel assemblies one by one, Road testing at
each step until the damaged tire(s)/wheel(s) as necessary. Test the
system for normal operation.
Wheel /tire noise, vibration and harshness concerns are directly related to vehicle speed and are not generally affected
by acceleration, coasting or decelerating. Also, out - of- balance wheel and tires can vibrate at more than one speed. A
vibration that is affected by the engine rpm, or is eliminated by placing the transmission in Neutral is not related to the
tire and wheel. As a general rule, tire and wheel vibrations felt in the steering wheel are related to the front tire and
wheel assemblies. Vibrations felt in the seat or floor are related to the rear tire and wheel assemblies. This can initially
isolate a concern to the front or rear.
Careful attention must be paid to the tire and wheels. There are several symptoms that can be caused by damaged or
worn tire and wheels. Perform a careful visual inspection of the tires and wheel assemblies. Spin the tires slowly and
watch for signs of lateral or radial runout. Refer to the tire wear chart to determine the tire wear conditions and actions WHEEL AND TIRE DIAGNOSIS
Rapid wear at the center Rapid wear at both shoulders Wear at one shoulder
a.Center - tread down to fabric due to
excessive over inflated tires
b. Lack of rotation
c. Excessive toe on drive wheels
d. Heavy acceleration on drive a.
Under- inflated tires
b. Worn suspension components
c. Excessive cornering speeds
d. Lack of rotation a.
Toe adjustment out of specification
b. Camber out of specification
c. Damaged strut
d. Damaged lower arm
Partial wear Feathered edge Wear pattern
a.Caused by irregular burrs on
brake drums a.
Toe adjustment out of
specification
b. Damaged or worn tie rods
c. Damaged knuckle a.
Excessive toe on non- drive
wheels
b. Lack of rotation