tires FORD MUSTANG 2003 User Guide

A rhythmic tap, similar to a clock noise.
Tip-
In Moan
A light moaning noise heard during light vehicle acceleration, usually between 40- 100 km/h (25-65
mph).
TIR
The acronym for total indicated runout is TIR.
Tire Deflection
The change in tire diameter in the area where the tire contacts the ground.
Tire Flat Spots
A condition commonly caused by letting the vehicle stand while the tires cool off. This condition can be
corrected by driving the vehicle until the tires are warm. Also, irregular tire wear patterns in the tire
tread resulting from wheel- locked skids.
Tire Force Vibration
A tire vibration caused by variations in the construction of the tire that is noticeable when the tire
rotates against the pavement. This condition can be present on perfectly round tires because of
variations in the inner tire construction. This condition can occur at wheel rotation frequency or twice
rotation frequency.
Transient
A noise or vibration that is momentary, a short duration.
Two- Plane Balance
Radial and lateral balance.
Vibration
Any motion, shaking or trembling, that can be felt or seen when an object moves back and forth or up
and down.
Whine
A constant, high- pitched noise. Also described as a screech.
Whistle
High- pitched noise (above 500 Hz) with a very narrow frequency band. Examples of whistle noises are
a turbocharger or airflow around an antenna.
Wind Noise
Any noise caused by air movement in, out or around the vehicle. Klj . 10 ba
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WOT
The acronym for wide open throttle is WOT.
Tools and Techniques
Electronic Vibration Analyzer (EVA)
The EVA is a hand-
held electronic diagnostic tool which will assist in locating the source of
unacceptable vibrations. The vibration sensor can be remotely mounted anywhere in the vehicle for
testing purposes. The unit displays the three most common vibration frequencies and their
corresponding amplitudes simultaneously. A bar graph provides a visual reference of the relative
signal strength (amplitude) of each vibration being displayed and its relative G force. The keypad is
arranged to make the EVA simple to program and use. Some of the functions include the ability to
average readings as well as record, play back and freeze readings. The EVA has a strobe balancing
function that can be used to detect imbalance on rotating components such as a driveshaft or engine
accessories.
The EVA allows for a systematic collection of information that is necessary to accurately diagnose and
repair NVH problems. For the best results, carry out the test as follows:
a. Test drive the vehicle with the vibration sensor inside the vehicle.
b. Place the sensor in the vehicle according to feel. „If the condition is felt through the steering wheel, the source is most likely in the front of
the vehicle.
„ A vibration that is felt in the seat or floor only will most likely be found in the driveline,
drive axle or rear wheels and tires.
c. Record the readings. Also note when the condition begins, when it reaches maximum intensity, and if it tends to diminish above/below a certain speed.
„Frequencies should be read in the "average" mode. Item Description
1 EVA screen
2 Frequency mode displayed in rpm or Hz
3 Active sensor input (A or B)
4 Current active mode
5 G force indicators or the strongest frequencies in descending strength of each vibration
6 Strength of each vibration
7 Frequency in rpm/Hz of each vibration Klj . 11 ba
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Neutral Coast Down Speed Test
To carry out this test, proceed as follows:
zDrive at a higher rate of speed than where the concern occurred when carrying out the Slow
Acceleration Test.
z Place the transmission in NEUTRAL and coast down past the speed where the concern occurs.
z The concern is vehicle speed- related if duplicated while carrying out this test. This eliminates
the engine and the torque converter as sources.
z If the concern was not duplicated while carrying out this test, carry out the Downshift Speed
Test to verify if the concern is engine speed related.
z Proceed as necessary.
Downshift Speed Test
To carry out this test, proceed as follows:
zShift into a lower gear than the gear used when carrying out the Slow Acceleration Test.
z Drive at the engine rpm where the concern occurs.
z The concern is engine speed related if duplicated while carrying out this test. This eliminates the
tires, wheels, brakes and the suspension components as sources.
z If necessary, repeat this test using other gears and NEUTRAL to verify the results.
z Proceed as necessary.
Steering Input Test
To carry out this test, proceed as follows:
zDrive at the speed where the concern occurs, while making sweeping turns in both directions.
z If the concern goes away or gets worse, the wheel bearings, hubs, U- joints (contained in the
axles of 4WD applications), and tire tread wear are all possible sources.
z Proceed as necessary.
Brake Test
To carry out this test, proceed as follows:
zWarm the brakes by slowing the vehicle a few times from 80–32 km/h (50–20 mph) using light
braking applications. At highway speeds of 89–97 km/h (50– 60 mph), apply the brake using a
light pedal force.
z Accelerate to 89–97 km/h (55–60 mph).
z Lightly apply the brakes and slow the vehicle to 30 km/h (20 mph).
z A brake vibration noise can be felt in the steering wheel, seat or brake pedal. A brake noise can
be heard upon brake application and diminish when the brake is released.
Road Test Over Bumps
To carry out this test, proceed as follows: Klj . 7 ba
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Section 204 - 01 .
z Damaged or
worn wheel
bearings z
CHECK for abnormal wheel
bearing play or roughness.
Refer to Wheel Bearing Check in this section.
ADJUST or INSTALL new
wheel bearings as
necessary.
z Clicking or
snapping— occurs
when accelerating
around a corner z
Damaged or
worn outboard
CV joint. z
INSPECT the outboard CV
joint and boot. REPAIR or
INSTALL a new CV joint as
necessary.
z High pitched
chattering— noise
from the rear axle
when the vehicle is
turning z
Incorrect or
contaminated
lubricant. z
CHECK the vehicle by
driving in tight circles (5
clockwise, 5
counterclockwise). FLUSH
and REFILL with the
specified rear axle lubricant
and friction modifier as
necessary.
z Damaged or
worn differential
(differential side
gears and pinion
gears). z
DISASSEMBLE the
differential assembly.
INSPECT the differential
case, pin and gears for wear
or damage. REPAIR or
INSTALL a new differential
as necessary. REFER to
Section 205 - 02A for Ford
7.5 rear axles or Section 205 - 02B for Ford 8.8
integral axles.
z Buzz—buzzing noise
is the same at cruise
or coast/deceleration z
Damaged or
worn tires. z
CHECK for abnormal tire
wear or damage. INSTALL a
new tire as necessary.
REFER to Section 204 - 04 .
z Incorrect
driveline angles. z
CHECK for correct driveline
angles. REPAIR as
necessary. REFER to
Section 205 - 00 .
z Rumble or boom—
noise occurs at
coast/deceleration,
usually driveshaft
speed related and
noticeable over a
wide range of speeds z
Driveshaft is
out-of- balance. z
CHECK the driveshaft for
damage, missing balance
weights or undercoating.
CHECK the driveshaft
balance. CARRY OUT a
driveline vibration test.
REFER to Section 205 - 00 .
z U-joints binding
or seized. z
ROTATE the driveshaft and
CHECK for rough operation
or seized U- joints. INSTALL
new U- joints as necessary.
REFER to Section 205 - 01 .
z Excessive
pinion flange
runout. z
CARRY OUT a runout
check. REPAIR as
necessary. REFER to
Section 205 - 00 .
z Grunting— normally
associated with a
shudder experienced
during acceleration z
Driveshaft slip
yoke binding. z
CLEAN and LUBRICATE
the male and female
splines. Klj . 20 ba
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01 .
z Damaged or
worn suspension
components. z
INSPECT the suspension
components for wear or
damage. REPAIR as
necessary.
z Loose wheel
nuts. z
CHECK the wheel nuts.
TIGHTEN to specification.
REFER to Section 204 -
04 .
z Damaged or
uneven tire wear. z
SPIN the tire and CHECK
for abnormal tire wear or
damage. INSTALL a new
tire as necessary. REFER
to Section 204 - 04 .
z Tire shimmy or
shake— occurs at
lower speeds z
Wheel/tire out of
balance. z
BALANCE the wheel/tire
assembly.
z Uneven tire wear. zCHECK for abnormal tire
wear. INSTALL a new tire
as necessary. REFER to
Section 204 - 04 .
z Excessive radial
runout of wheel
or tire. z
CARRY OUT a radial
runout test of the wheel
and tire. INSTALL a new
tire as necessary. REFER
to Section 204 - 04 .
z Worn or
damaged wheel
studs or
elongated stud
holes. z
INSPECT the wheel studs
and wheels. INSTALL new
components as necessary.
REFER to Section 204 - 01
for the front wheels or
Section 204
- 02 for the rear
wheels.
z Excessive lateral
runout of the
wheel or tire. z
CARRY OUT a lateral
runout test of the wheel
and tire. CHECK the
wheel, tire and hub.
REPAIR or INSTALL new
components as necessary.
z Foreign material
between the
brake disc and
hub or in the
brake disc fins. z
CLEAN the mounting
surfaces of the brake disc
and hub. CHECK the
brake disc fins for material.
z High speed shake or
shimmy—occurs at
high speeds z
Excessive wheel
hub runout.
z Damaged or
worn tires.
z Damaged or
worn wheel
bearings.
z Worn or
damaged
suspension or
steering linkage
components.
z Brake disc or
drum imbalance. z
Go To Pinpoint Test K . Klj . 39 ba
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information, REFER to
Section 205
- 00 .
REPAIR as necessary.
z Transmission
rumble/growl— noise at
all speeds in forward
gears, more
pronounced in a heavy
acceleration condition z
Damaged or worn
transmission
bearing or gears
(high mileage
vehicles). z
CHECK transmission
fluid for excessive
metal particles.
REPAIR as necessary.
REFER to Section 308 -
03A for T50D
transmissions or
Section 308 - 03B for
TR3650 transmissions.
z Transfer case whine—
noise at all ranges z
Incorrect fluid level
or fluid quality. z
CHECK that the
transfer case is filled to
the correct level and
with the specified fluid.
REFER to Section 308 -
03A for T50D
transmissions or
Section 308 - 03B for
TR3650 transmissions.
z Worn oil pump. zDISASSEMBLE the
transfer case. CHECK
the oil pump for wear or
damage. REPAIR as
necessary.
z Under- inflated or
oversized tires. z
CONFIRM that the tires
and wheels are correct
for the vehicle. CHECK
that the tire inflation
pressures are correct.
z Transfer case
growl/rumble— noise at
all ranges (A small
amount of planetary
noise can be heard
when the transfer case
is operated in low
range.) z
Damaged or worn
bearings or
planetary gear. z
DISASSEMBLE the
transfer case. CHECK
the bearings or
planetary gear for wear
or damage. REPAIR as
necessary.
z Transfer case
scraping/grating—
noise at all ranges z
Excessively
stretched drive
chain hitting the
case. z
DISASSEMBLE the
transfer case. CHECK
the drive chain for wear
or damage. REPAIR as
necessary.
z Transfer case
howl/hum— noise at all
ranges or high range
only z
Worn or damaged
sun (input) gear,
clutch pack
(intermediate) gear
or output shaft gear. z
DISASSEMBLE the
transfer case. CHECK
the gears for wear or
damage. REPAIR as
necessary.
z Transfer case
howl/hum— noise at
low range only z
Worn or damaged
intermediate gear
and sliding gears
(clutch pack). z
DISASSEMBLE the
transfer case. CHECK
the gears for wear or
damage. REPAIR as
necessary.
z Transfer case
vibration— vibration felt
with vehicle in 4WD z
Transfer case
mounting.
z Driveshaft out of
balance.
z Excessive pinion z
Go To Pinpoint Test M . Klj . 44 ba
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condition. It may not always be necessary to follow a pinpoint test to its conclusion. Carry out only the
steps necessary to correct the condition. Then, test the system for normal operation. Sometimes, it is
necessary to remove various vehicle components to gain access to the component requiring testing.
Reinstall all components after verifying system operation is normal.
PINPOINT TEST A: BRAKE VIBRATION/SHUDDER
Test Step Result / Action to Take
A1 ROAD TEST THE VEHICLE—
LIGHT BRAKING z
Check that the wheel and tires are correct for the vehicle.
Inspect the tires for abnormal wear patterns.
z Road test the vehicle. Warm the brakes by slowing the vehicle
a few times from 80– 32 km/h (50 to 20 mph) using light braking
applications. At highway speeds of 89–97 km/h (55- 60 mph),
apply the brake using a light pedal force.
z Is there a vibration/shudder felt in the steering wheel, seat
or brake pedal? Yes
GO to
A4 .
No
GO to A2 .
A2 ROAD TEST THE VEHICLE—
MODERATE TO HEAVY
BRAKING z
Road test the vehicle. At highway speeds of 89–97 km/h (55- 60
mph), apply the brake using a moderate to heavy pedal force.
z Is there a vibration/shudder? Yes
For vehicles with ABS,
GO to
A3 . For vehicles
with standard brakes,
GO to A4 .
No
Vehicle is OK. VERIFY
condition with customer.
TEST the vehicle for
normal operation. A3 NORMAL ACTUATION OF THE ABS SYSTEM DIAGNOSIS
z
During moderate to heavy braking, noise from the hydraulic
control unit (HCU) and pulsation in the brake pedal can be
observed. Pedal pulsation coupled with noise during heavy
braking or on loose gravel, bumps, wet or snowy surfaces is
acceptable and indicates correct functioning of the ABS
system. Pedal pulsation or steering wheel nibble, (frequency is
proportioned to the vehicle speed) indicates a concern with a
brake or suspension component.
z Is the vibration/shudder vehicle speed sensitive? Yes
GO to
A5 .
No
The brake system is
operating correctly. A4 APPLICATION OF THE PARKING BRAKE
z
NOTE: Begin at the front of the vehicle unless the vibration or
shudder has been isolated to the rear.
z This test is not applicable to vehicles with drum- in-hat type
parking brakes. For vehicles with drum- in-hat parking brakes,
proceed to the next test. For all other vehicles, apply the
parking brake to identify if the problem is in the front or rear
brake. At highway speeds of 89–97 km/h (55- 60 mph), lightly
apply the parking brake until the vehicle slows down. Release
the parking brake immediately after the test.
z Is there a vibration/shudder? Yes
GO to
A7 .
No
GO to A5 .
A5 CHECK THE FRONT WHEEL BEARINGS
z
Check the front wheel bearings. Refer to Wheel Bearing Check in this section.
z Are the wheel bearings OK? Yes
GO to
A6 . Klj . 48 ba
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Take
J1 ROAD TEST THE VEHICLE
z
NOTE: Wheel or tire vibrations felt in the steering wheel are most
likely related to the front wheel or tire. Vibration felt through the
seat are most likely related to the rear wheel or tire. This may not
always be true, but it can help to isolate the problem to the front
or rear of the vehicle.
z Test drive the vehicle at different speed ranges.
z During the road test, if the vibration can be eliminated by placing
the vehicle in neutral or is affected by the speed of the engine,
the cause is not the wheels or tires.
z Is there a vibration and noise? Yes
GO to
J2 .
No
The wheel and tires
are OK. CONDUCT a
diagnosis on other
suspect systems. J2 CHECK THE FRONT WHEEL BEARINGS
z
Check the front wheel bearings. Refer to Wheel Bearing Check in
this section.
z Are the wheel bearings OK? Yes
GO to
J3 .
No
INSPECT the wheel
bearings. ADJUST or
REPAIR as necessary.
TEST the system for
normal operation. J3 INSPECT THE TIRES
z
Check the tires for missing weights.
z Check the wheels for damage.
z Inspect the tire wear pattern. Refer to the Tire Wear Patterns
chart in this section.
z 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
J4 .
J4 TIRE ROTATION
z
Spin the tires slowly and watch for signs of lateral runout.
z Spin the tires slowly and watch for signs of radial runout. Yes
GO to
J5 .
No
CHECK the wheel and
tire balance.
CORRECT as
necessary. TEST the
system for normal
operation. Klj . 56 ba
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z
Are there signs of visual runout? J5 RADIAL RUNOUT CHECK ON THE TIRE
z
Measure the radial runout of the wheel and tire assembly. A
typical specification for total radial runout is 0.045 inch.
z Is the radial runout within specifications? Yes
GO to
J8 .
No
GO to J6 .
J6 RADIAL RUNOUT CHECK ON THE WHEEL
z
Measure the radial runout of the wheel. A typical specification for
total radial runout is 0.045 inch.
z Is the radial runout within specifications? Yes
INSTALL a new tire.
TEST the system for
normal operation.
No
GO to
J7 .
J7 CHECK THE HUB/BRAKE DISC OR DRUM PILOT RUNOUT OR
BOLT CIRCLE RUNOUT z
Measure the pilot or bolt circle runout. A typical specification for
radial runout is:
zPilot runout— less than 0.15 mm (0.006 inch).
z Bolt circle runout— less than 0.38 mm (0.015 inch).
z Is the radial runout within specifications? Yes
INSTALL a new wheel.
TEST the system for
normal operation.
No
REPAIR or INSTALL
new components as
necessary. REFER to
Section 204
- 01 for the
front wheels or Section 204 - 02 for the rear
wheels. J8 LATERAL RUNOUT CHECK ON THE TIRE
z
Measure the lateral runout of the wheel and tire assembly. A
typical specification for total lateral runout is 1.14 mm (0.045
inch). Yes
Wheel and tires OK.
CONDUCT diagnosis
on other suspect
systems. Klj . 57 ba
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PINPOINT TEST K: HIGH SPEED SHAKE OR SHIMMY z
Is the lateral runout within specifications? No
GO to
J9 .
J9 LATERAL RUNOUT CHECK ON THE WHEEL
z
Measure the lateral runout of the wheel. A typical specification for
total radial runout is 1.14mm (0.045 inch.
z Is the lateral runout within specifications? Yes
INSTALL a new tire.
TEST the system for
normal operation.
No
GO to
J10 .
J10 CHECK THE FLANGE FACE LATERAL RUNOUT
z
Measure the flange face lateral runout. A typical specification for
lateral runout is:
zHub/brake disc— less than 0.13 mm (0.005 inch).
z Axle shaft— less than 0.25 mm (0.010 inch).
z 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. REFER to
Section 204
- 01 for the
front wheels or Section 204 - 02 for the rear
wheels. Test Step Result / Action to Take
K1 CHECK FOR FRONT WHEEL BEARING ROUGHNESS
z
Chock the rear wheels.
z Raise and support the front end of the vehicle so that the front
wheel and tire assemblies can spin.
z Spin the front tires by hand. Refer to Wheel Bearing Check in
this section.
z Do the wheel bearings feel rough? Yes
INSPECT the wheel
bearings. REPAIR as
necessary. TEST the
system for normal
operation.
No
GO to
K2 .
K2 CHECK THE END PLAY OF THE FRONT WHEEL BEARINGS
z
Check the end play of the front wheel bearings. Refer to
Section 204 - 01 .
z Is the end play OK? Yes
GO to
K3 .
No
ADJUST or REPAIR as
necessary. TEST the
system for normal Klj . 58 ba
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