light FORD MUSTANG 2003 Owner's Manual

flange runout.
Symptom Chart—
Transmission (Automatic) Noise/Vibration Condition
Possible Sources Action
z Rattle— occurs
at idle or at
light
acceleration
from a stop z
Damaged engine or
transmission mounts. z
CHECK the
powertrain/drivetrain mounts
for damage. REPAIR or
INSTALL new mounts as
necessary.
z A loose front exhaust
pipe heat shield. z
REPAIR or INSTALL a new
heat shield as necessary.
z Loose inspection
plate or dust cover
plate. z
CHECK for loose bolts.
TIGHTEN to specifications.
REFER to Section 307 - 01 .
z Loose flex plate to
converter nuts. z
CHECK for loose nuts.
TIGHTEN to specifications.
REFER to Section 307 - 01 .
z Whine— pitch
increases with
vehicle speed.
Starts in first
and second
gear,
decreases or
goes away at
higher gears z
Damaged or worn low
one- way clutch.
z Damaged or worn
intermediate one- way
clutch.
z Friction elements.
z Damaged or worn
planetary or sun gear. z
INSPECT the transmission
for wear or damage. REPAIR
or INSTALL new components
as necessary. REFER to
Section 307 - 01 .
z Whine— the
pitch changes
with engine
speed z
A worn or damaged
accessory drive
component. z
CARRY OUT the Engine
Accessory Test. REPAIR or
INSTALL new components as
necessary.
z Incorrect fluid level. zCHECK that the transmission
is filled to the correct level.
ADD fluid as necessary.
REFER to Section 307 - 01 .
z Partially blocked filter. zINSPECT the filter. CLEAN or
INSTALL a new filter as
necessary. REFER to Section 307 - 01 .
z Worn or damaged
torque converter. z
CARRY OUT the torque
converter service and
replacement check. REFER
to Section 307 - 01 .
z Worn or damaged
front pump. z
INSPECT the front pump.
INSTALL a new front pump
as necessary. REFER to
Section 307 - 01 .
z Whine— pitch
changes with
vehicle speed z
Speedometer cable
or gears. z
REPAIR or INSTALL new
cables or gears as necessary.
z Whine/moan
type noise—
pitch increases
or changes
with vehicle
speed z
Damaged engine or
transmission mount. z
CHECK the
powertrain/drivetrain mounts
for damage. CARRY OUT
Powertrain/Drivetrain Mount Neutralizing in this section.
z U-joints worn or zINSPECT the U- joints for Klj . 45 ba
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Pinpoint Tests
The pinpoint tests are a step-by-
step diagnostic process designed to determine the cause of a z
Bump—occurs
when shifting
from PARK to
a drive or
reverse
position.
Similar to
Clunk but with
no sound z
Initial gear
engagement. z
Acceptable condition.
z Buzz or hiss zIncorrect driveline
angles. z
CHECK for correct driveline
angles. REPAIR as
necessary. REFER to Section 205 - 00 .
z Worn or damaged
main control
solenoids or valves. z
Using a transmission tester,
ACTIVATE the solenoids to
duplicate sound. INSTALL
new components as
necessary. REFER to Section 307 - 01 .
z Vibration— a
high frequency
(20–80 Hz) that
is felt through
the seat or
gear shifter.
Changes with
engine speed z
Transmission cooler
lines grounded out. z
CHECK the transmission
cooler lines. REPAIR as
necessary.
z Flexplate to torque
converter nuts loose. z
CHECK the flexplate nuts.
TIGHTEN to specification.
REFER to Section 307 - 01 .
z Fluid filler tube
grounded out. z
CHECK the fluid filler tube.
REPAIR as necessary.
z Shift cable incorrectly
routed, grounded out
or loose. z
CHECK the shift cable.
REPAIR as necessary.
Section 307 - 05 .
z Shutter or
chatter—
occurs with
light to medium
acceleration
from low
speeds or a
stop z
Electrical
inputs/outputs.
z Vehicle wiring
harness.
z Incorrect
inputs/outputs from
the powertrain control
module (PCM), digital
transmission range
(TR) sensor, brake
pedal position (BPP)
sensor, throttle
position (TP) sensor,
transmission speed
sensor (TSS), output
speed shaft (OSS)
sensor or the torque
converter clutch
(TCC). z
CARRY OUT a Torque
Converter Clutch Operation
Test. RUN on- board
diagnostics or self- test.
REFER to Section 307 - 01 .
CLEAR the DTC's, ROAD
TEST and RERUN on- board
diagnostics or self- test. Klj . 47 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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4. While the noise is occurring, either place an EngineEAR probe near the IAC valve and the inlet
tube, or create a 6.35 mm (0.25 in)- 12.7 mm (0.50 in) air gap between the inlet tube and the
clean air tube. If the IAC valve is making the noise, install a new IAC valve.
5. Test the vehicle for normal operation.
Steering Gear Grunt/Shudder Test
1. Start and run the vehicle to operating temperature.
2. Set engine idle speed to 1200 rpm.
3. CAUTION: Do not hold the steering wheel against the stops for more than three to
five seconds at a time. Damage to the power steering pump will occur.
Rotate the steering wheel to the RH stop, then turn the steering wheel 90° back from that
position. Turn the steering wheel slowly in a 15° to 30° arc.
4. Turn the steering wheel another 90°. Turn the steering wheel slowly in a 15° to 30° arc.
5. Repeat the test with power steering fluid at different temperatures.
6. If a light grunt is heard or a low (50- 200 Hz) shudder is present, this is a normal steering system
condition.
7. If a loud grunt is heard, or a strong shudder is felt, fill and purge the power steering system.
Checking Tooth Contact Pattern and Condition of the Ring and Pinion
There are two basic types of conditions that will produce ring and pinion noise. The first type is a howl
or chuckle produced by broken, cracked, chipped, scored or forcibly damaged gear teeth and is
usually quite audible over the entire speed range. The second type of ring and pinion noise pertains to
the mesh pattern of the gear pattern. This gear noise can be recognized as it produces a cycling pitch
or whine. Ring and pinion noise tends to peak in a narrow speed range or ranges, and will tend to
remain constant in pitch.
1. Raise and support the vehicle. For additional information, refer to Section 100 - 02 .
2. Drain the axle lubricant. Refer to Section 205 - 02A for Ford 7.5 rear axles or
Section 205 - 02B for
Ford 8.8 integral axles.
3. Remove the carrier assembly or the axle housing cover depending on the axle type. Refer to Section 205 - 02A for Ford 7.5 rear axles or
Section 205 - 02B for Ford 8.8 integral axles.
4. Inspect the gear set for scoring or damage. Klj . 64 ba
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5. In the following steps, the movement of the contact pattern along the length is indicated as
toward the" heel" or "toe" of the differential ring gear.
6. Apply a marking compound to a third of the gear teeth on the differential ring gear. Rotate the differential ring gear several complete turns in both directions until a good, clear tooth pattern is
obtained. Inspect the contact patterns on the ring gear teeth.
7. A good contact pattern should be centered on the tooth. It can also be slightly toward the toe. There should always be some clearance between the contact pattern and the top of the tooth.
z Tooth contact pattern shown on the drive side of the gear teeth. 8. A high, thick contact pattern that is worn more toward the toe. Item Description
1 Heel
2 Toe Klj . 65 ba
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6. For vehicles with a two-
piece hub and brake disc assembly:
z Match-mark before disassembly.
z Remove the brake disc.
z Clean the hub and brake disc mounting surfaces with metal surface cleaner.
z Using a die grinder with a mild abrasive (Scotch Brite® type), remove any rust or
corrosion from the hub and brake disc mounting surfaces.
z Align the match- marks and reinstall the brake disc on the hub.
7. CAUTION: Do not use a bench lathe to machine brake discs.
NOTE: The depth of cut must be between 0.10 and 0.20 mm (0.004 and 0.008 inch). Lighter
cuts will cause heat and wear. Heavier cuts will cause poor brake disc surface finish.
Using an on- car brake lathe, machine the brake discs. Follow the manufacturer's instructions.
After machining, make sure the brake disc still meets the thickness specification.
8. Using the special tools, verify that the brake disc lateral runout is now within specification. For additional information, refer to Section 206 - 00 .
9. Remove the special tool hub adapter.
10. Remove any remaining metal chips from the machining operation.
11. For vehicles with a two- piece hub and brake disc assembly:
z Remove the brake disc from the hub.
z Remove any remaining metal chips from hub and brake disc mounting surfaces and from
the ABS sensor.
z Apply a liberal amount of lubricant to the hub flange, pilot area and to the brake disc- to-
hub mounting surface.
z Using the match marks, mount the brake disc on the hub.
12. Install the brake caliper anchor plate and the brake caliper.
13. Install the tire and wheel assembly.
14. Test the system for normal operation. Klj . 2 ba
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DIAGNOSIS AND TESTING
Suspension System
Inspection and Verification
1. Road test. zVerify the customer's concern by performing a road test on a smooth road.
2. Inspect tires. zCheck the tire pressure with all normal loads in the vehicle and the tires cold. For
additional information, refer to the vehicle certification (VC) label.
z Verify that all tires are sized to specification.
z Inspect the tires for incorrect wear and damage.
3. Inspect chassis and underbody. zRemove any excessive accumulation of mud, dirt or road deposits from the chassis and
underbody.
4. Inspect for aftermarket equipment. zCheck for aftermarket changes to the steering, suspension, wheel and tire components
(such as competition, heavy duty, etc.) The specifications shown in this manual do not
apply to vehicles equipped with aftermarket equipment.
5. Inspect shock absorbers. All vehicles are equipped with gas- pressurized hydraulic shock absorbers. These shock
absorbers are not adjustable or refillable and cannot be repaired.
zOil Leak: A light film of oil (weepage) on the upper portion of the shock absorber is
permissible and is a result or correct shock lubrication. Weepage is a condition in which a
film of oil accumulates on the thin tube (body) and is normally noticed due to the
collection of dust in this area. If shock absorbers exhibit this weepage condition, they are
functional units and new shock absorbers should not be installed. Leakage is a condition
in which the entire shock absorber body is covered with oil and the oil will drip from the
shock absorber onto the pavement. If condition exists:
„Make sure fluid observed is not from sources other than the shock absorber.
„ Install a new shock absorber, if necessary.
z Vehicle Sag: Many times new shock absorbers are installed in an effort to solve a vehicle
sag concern. Shock absorbers by design are hydraulic damping units only and, unlike
suspension springs, do not support any suspension loads. Therefore, installing a new
shock absorber will not correct a vehicle sag concern.
z Installment in Pairs: In the past it was recommended that new shock absorbers be
installed in pairs if one unit became unrepairable. New shock absorbers no longer need
to be installed in pairs when only one unit is not repairable.
SECTION 204-
00: Suspension System — General Information 2003 Mustang Workshop Manual Visual Inspection Chart
Mechanical Klj . 1 ba
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Inspection and Verification
Certain axle noise or vibration symptoms are also common to the engine, transmission, wheel
bearings, tires, and other parts of the vehicle. For this reason, be sure that the cause of the trouble is
in the axle before disassembling, adjusting or repairing the axle. Refer to
Section 100 - 04 .
Certain driveshaft vibration symptoms are common to the front engine accessory drive (FEAD), the
engine, transmission or tires. Be sure the cause of the concern is the driveshaft before repairing or
installing a new driveshaft. Refer to Section 100 - 04 .
Certain symptoms may be caused by Traction- Lok® differentials (4026). Check the vehicle certification
label and axle identification tag to determine the type of differential. Refer to Section 100 - 01 .
Noise Acceptability
NOTE: A gear-driven unit will produce a certain amount of noise. Some noise is acceptable and
audible at certain speeds or under various driving conditions such as a newly paved blacktop road.
Slight noise is not detrimental to the operation of the axle and is considered normal.
With the Traction- Lok® differential axle, slight chatter noise on slow turns after extended highway
driving is considered acceptable and has no detrimental effect on the locking axle function.
Universal Joint (U- Joint) Inspection
Place the vehicle on a frame hoist and rotate the driveshaft (4602) by hand. Check for rough operation
or seized U- joints. Install a new U- joint if it shows signs of seizure, excessive wear, or incorrect
seating. Refer to Section 205 - 01 .
Analysis of Leakage
Clean up the leaking area enough to identify the exact source. An axle leak can be caused by the
following. zAxle lubricant level is too high.
z Worn or damaged axle shaft seals or differential seals.
z Differential housing is cracked.
z Flange yoke seat is worn or damaged.
z Pinion flange is scored or damaged.
z Axle cover is not sealed.
z Vent is plugged. Klj . 2 ba
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Component Tests
Driveline Vibration
An analysis of driveline vibration can also be conducted using the Vibration Analyzer; follow the
manufacturer's directions.
Driveline vibration exhibits a higher frequency and lower amplitude than does high-
speed shake.
Driveline vibration is directly related to the speed of the vehicle and is usually noticed at various speed
ranges. Driveline vibration can be perceived as a tremor in the floorpan or is heard as a rumble, hum,
or boom. Driveline vibration can exist in all drive modes, but may exhibit different symptoms depending
upon whether the vehicle is accelerating, decelerating, floating, or coasting. Check the driveline angles
if the vibration is particularly noticeable during acceleration or deceleration, especially at lower speeds.
Driveline vibration can be duplicated by supporting the axle upon a hoist or upon jack stands, though
the brakes may need to be applied lightly in order to simulate road resistance.
1. Raise the vehicle promptly after road testing. Use a twin- post hoist or jack stands to prevent tire
flat- spotting. Engage the drivetrain and accelerate to the observed road test speed to verify the lubricant type.
205 - 02B . CLEAN and
REFILL the axle to
specification.
z Axle overheating zLubricant level too
low. z
CHECK the lubricant level.
FILL the axle to specification.
z Incorrect or
contaminated
lubricant type. z
INSPECT the axle for
damage. REPAIR as
necessary. CLEAN and
REFILL the axle to
specification.
z Bearing preload
adjusted too tight. z
CHECK the ring and pinion for
damage. INSPECT the ring
and pinion wear pattern.
ADJUST the preload as
necessary.
z Excessive gear
wear. z
INSPECT all the axle gears
for wear or damage. INSTALL
new components as
necessary.
z Incorrect ring gear
backlash. z
INSPECT the ring gear for
scoring. INSPECT the ring
and pinion wear pattern.
ADJUST the ring gear
backlash as necessary.
z Broken gear teeth
on the ring gear
or pinion z
Overloading the
vehicle. z
INSTALL a new ring and
pinion. REFER to Section 205 - 02A or
Section 205 - 02B .
z Axle shaft broken zOverloading the
vehicle. z
INSTALL a new axle shaft.
REFER to Section 205 - 02A or
Section 205 - 02B .
z Misaligned axle
shaft tube. z
INSPECT the axle for
damage. CHECK axle shaft
tube alignment. INSTALL a
new axle shaft. REFER to
Section 205 - 02A or
Section 205 - 02B . Klj . 11 ba
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off the floor.
With the engine off, raise only one rear wheel. Install the special tool on the wheel nuts.
Use a torque wrench with a capacity of at least 271 Nm (200 lb-
ft) to rotate the axle shaft. Be sure that
the transmission is in NEUTRAL, and that one rear wheel is on the floor while the other rear wheel is
raised off the floor. The breakaway torque required to start rotation must be at least 27 Nm (20 lb- ft).
The initial breakaway torque may be higher than the continuous turning torque.
The axle shaft must turn with even pressure throughout the check without slipping or binding. If the
torque reading is less than specified, check the differential case. Refer to Section 205 - 02A or
Section 205 - 02B .
Traction- Lok® Differential Check Road Test
1. Place one wheel on a dry surface and the other wheel on ice, mud or snow.
2. Gradually open the throttle to obtain maximum traction prior to break away. The ability to move the vehicle demonstrates correct operation of a Traction- Lok® rear axle assembly.
3. When starting with one wheel on an excessively slippery surface, a slight application of the parking brake may be necessary to help energize the Traction- Lok® feature of the differential.
Release the brake when traction is established. Use light throttle on starting to provide
maximum traction.
4. If, with unequal traction, both wheels slip, the limited slip rear axle has done all it can possibly do.
5. In extreme cases of differences in traction, the wheel with the least traction may spin after the Traction-Lok® has transferred as much torque as possible to the non- slipping wheel. Klj . 15 ba
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