differential FORD MUSTANG 2003 Workshop Manual

DESCRIPTION AND OPERATION
Jacking
WARNING: Never run the engine with one wheel off the ground, such as when changing a
tire. The wheel still on the ground could cause the vehicle to move.
CAUTION: The jack (17080) provided with the vehicle is intended to be used in an
emergency for changing a deflated tire. To avoid damage to the vehicle, never use the jack to
lift the vehicle for any other purpose. Refer to the Owner Guide when using the jack supplied
with the vehicle.
CAUTION: Under no circumstances should the vehicle ever be lifted by the suspension
arm brackets, rear stabilizer or differential housing or convertible cross brace. Severe damage
to the vehicle could result.
CAUTION: Do not attempt to use jack pressure on either the front bumper (17757) or the
rear bumper (17906) of any vehicle. Damage to the bumper covers will occur.
Lift the vehicle using the Jacking Points procedure in this section.
Jacking Points
To lift the front or either side of the front end, position the floor jack under the front frame lift points. SECTION 100-
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DESCRIPTION AND OPERATION
Lifting
CAUTION: Do not allow the lift adapters to contact the steering linkage, suspension arms,
stabilizer arms, or to compress the lower suspension arm stabilizer bar insulator (5493).
Damage to the suspension, exhaust and steering linkage components may occur if care is not
exercised when positioning the hoist adapters prior to lifting the vehicle.
CAUTION: Never use the differential housing as a lift point. Damage to the differential
housing and cover may occur.
CAUTION: Do not lift vehicle on rocker panel pinch flange or convertible cross brace.
Body damage may occur.
Lift the vehicle using the Lifting Points procedure in this section.
Lifting Points—Drive On Lift
CAUTION: To prevent possible damage to the underbody, do not drive the vehicle onto
the drive on lift without first checking for possible interference.
Check for interference between the upright flanges of the hoist rails and the underbody.
If an interference exists, modify the hoist flanges or build up the approach ramps as necessary to
provide clearance. Lifting Points — Frame Contact Lift, Single Post Lift, Two Post Lift SECTION 100-
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DESCRIPTION AND OPERATION
Noise, Vibration and Harshness (NVH)
Noise is any undesirable sound, usually unpleasant in nature. Vibration is any motion, shaking or
trembling, that can be felt or seen when an object moves back and forth or up and down. Harshness is
a ride quality issue where the vehicle's response to the road transmits sharply to the customer.
Harshness normally describes a firmer than usual response from the suspension system. Noise,
vibration and harshness (NVH) is a term used to describe these conditions, which result in varying
degrees of dissatisfaction. Although, a certain level of NVH caused by road and environmental
conditions is normal. This section is designed to aid in the diagnosis, testing and repair of NVH
concerns.
Acceptable Noise, Vibration and Harshness
All internal combustion engines and drivelines produce some noise and vibration; operating in a real
world environment adds noise that is not subject to control. Vibration isolators, mufflers and dampers
reduce these to acceptable levels. A driver who is unfamiliar with a vehicle can think that some sounds
are abnormal when actually the sounds are normal for the vehicle type. For example, Traction-
Lok®
differentials produce a slight noise on slow turns after extended highway driving. This is acceptable
and has no detrimental effect on the locking axle function. As a technician, it is very important to be
familiar with vehicle features and know how they relate to NVH concerns and their diagnosis. For
example, if the vehicle has automatic overdrive, it is important to test drive the vehicle both in and out
of overdrive mode.
Diagnostic Theory
The shortest route to an accurate diagnosis results from:
zsystem knowledge, including comparison with a known good system.
z system history, including repair history and usage patterns.
z condition history, especially any relationship to repairs or sudden change.
z knowledge of possible sources.
z using a systematic diagnostic method that divides the system into related areas.
The diagnosis and correction of noise, vibration and harshness concerns requires:
za road or system test to determine the exact nature of the concern.
z an analysis of the possible causes.
z testing to verify the cause.
z repairing any concerns found.
z a road test or system test to make sure the concern has been corrected or brought back to
within an acceptable range.
Glossary of Terms SECTION 100-
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z
After determining the "system", use the diagnostic tools to identify the worn or damaged
"components".
z After identifying the "components", try to find the "cause" of the failure.
Once the concern is narrowed down to a symptom/condition, proceed to NVH Condition and Symptom
Categories.
NVH Condition and Symptom Categories
A good diagnostic process is a logical sequence of steps that lead to the identification of a causal
system. Use the condition and symptom categories as follows:
zIdentify the operating condition that the vehicle is exhibiting.
z Match the operating condition to the symptom.
z Verify the symptom.
z Identify which category or system could cause the symptom.
z Refer to the diagnostic symptom chart that is referred to.
Operating Condition— Vehicle is Not Moving
1. Static operation zNoise occurs during component/system functioning. GO to Symptom Chart — Squeak
and Rattle .
2. While cranking 1. Grinding or whine, differential ring gear or starter motor pinion noise. GO to Symptom Chart — Engine Noise/Vibration .
2. Rattle. Exhaust hanger, exhaust heat shield or A/C line noise. GO to Symptom Chart —
Squeak and Rattle .
3. Vibration. Acceptable condition.
3. At idle zIdle noise. GO to Symptom Chart — Idle Noise/Vibration .
z Idle vibration or shake. GO to Symptom Chart — Idle Noise/Vibration .
4. During Gear Selection 1. Vehicle parked on a steep incline. Acceptable noise.
2. Vehicle parked on a flat surface. GO to Symptom Chart — Driveline Noise/Vibration .
3. Vehicle with a manual transmission. GO to Symptom Chart — Transmission (Manual)
and Transfer Case Noise/Vibration .
Operating Condition— Vehicle is Moving
1. Depends more on how the vehicle is operated 1. Speed related
„Related to vehicle speed
„Pitch increases with vehicle speed. GO to Symptom Chart — Tire
Noise/Vibration .
„ Noise occurs at specific vehicle speed. A high- pitched noise (whine). GO to
Symptom Chart — Driveline Noise/Vibration . Klj . 10 ba
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damage.
for damage. REPAIR or
INSTALL a new axle as
necessary. REFER to
Section 205 - 02A for Ford
7.5 rear axles or Section 205 - 02B for Ford 8.8
integral axles.
z Damaged or
worn wheel
bearings or axle
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 Damaged or
worn differential
ring and pinion. z
INSPECT the ring and
pinion ring for abnormal
wear patterns or broken
teeth. INSTALL a new ring
and pinion as necessary.
REFER to Section 205 - 02A
for Ford 7.5 rear axles or
Section 205
- 02B for Ford
8.8 integral axles.
z Damaged or
worn differential
side or pinion
bearings. z
CHECK for abnormal
bearing play or roughness.
INSTALL new bearings as
necessary.
z Damaged or
worn differential
side gears and
pinion gears. z
DISASSEMBLE the
differential carrier. INSPECT
the side and pinion gears for
abnormal wear patterns or
broken teeth. INSTALL new
gears as necessary. REFER
to Section 205 - 02A for Ford
7.5 rear axles or Section 205 - 02B for Ford 8.8
integral axles.
z Driveline clunk— loud
clunk when shifting
from reverse to drive z
Incorrect axle
lubricant level. z
CHECK the lubricant level.
FILL the axle to
specification.
z Excessive
backlash in the
axle or
transmission. z
CARRY OUT a total
backlash check. REFER to
Section 205 - 00 .
z Damaged or
worn pinion
bearings. z
CHECK for abnormal
bearing play or roughness.
INSTALL new bearings as
necessary. REFER to
Section 205 - 02A for Ford
7.5 rear axles or Section 205 - 02B for Ford 8.8
integral axles.
z Damaged or
worn universal
joints (U- joints). z
INSPECT the U- joints for
wear or damage. INSTALL
new U- joints as necessary.
REFER to Section 205 - 01 .
z Loose
suspension
components. z
INSPECT the suspension
for damage or wear.
REPAIR or INSTALL new Klj . 18 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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from a dead stop
zLoose rear
spring U- bolts. z
INSPECT the rear
suspension. TIGHTEN the
U-bolt nuts to specification.
REFER to Section 204 - 02 .
z Howl— can occur at
various speeds and
driving conditions.
Affected by
acceleration and
deceleration z
Incorrect ring
and pinion
contact,
incorrect
bearing preload
or gear damage. z
CHECK the ring and pinion
and bearings for damage.
INSPECT the ring and
pinion wear pattern. REFER
to Checking Tooth Contact
Pattern and Condition of the
Ring and Pinion component
test in this section. ADJUST
or INSTALL new
components as necessary.
REFER to Section 205 - 02A
for Ford 7.5 rear axles or
Section 205
- 02B for Ford
8.8 integral axles.
z Chuckle— heard at
coast/deceleration.
Also described as a
knock z
Incorrect ring
and pinion
contact or by
damaged teeth
on the coast
side of the ring
and pinion. z
CHECK the ring and pinion
for damage. INSPECT the
ring and pinion wear pattern.
REFER to Checking Tooth
Contact Pattern and
Condition of the Ring and
Pinion component test in
this section. ADJUST or
INSTALL new components
as necessary. REFER to
Section 205 - 02A for Ford
7.5 rear axles or Section 205 - 02B for Ford 8.8
integral axles.
z Knock— noise occurs
at various speeds.
Not affected by
acceleration or
deceleration z
Gear tooth
damage to the
drive side of the
ring and pinion. z
CHECK the differential case
and ring and pinion for
damage. INSTALL new
components as necessary.
REFER to Section 205 - 02A
for Ford 7.5 rear axles or
Section 205
- 02B for Ford
8.8 integral axles.
z Excessive axle
shaft end play.
(Vehicles with
integral axles). z
CHECK the axle end play
using a dial indicator.
INSTALL a new axle shaft
or side gears as necessary.
REFER to Section 205 - 02A
for Ford 7.5 rear axles or
Section 205
- 02B for Ford
8.8 integral axles.
z Scraping noise— a
continuous low
pitched noise starting
at low speeds z
Worn or
damaged pinion
bearings. z
CHECK the pinion bearings.
INSTALL new pinion
bearings as necessary.
REFER to Section 205 - 02A
for Ford 7.5 rear axles or
Section 205
- 02B for Ford
8.8 integral axles.
z Driveline shudder—
occurs during
acceleration from a
slow speed or stop z
Rear drive axle
assembly
mispositioned. z
CHECK the axle mounts
and the rear suspension for
damage or wear. REPAIR
as necessary. Klj . 21 ba
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damaged.
wear or damage. INSTALL
new U-joints as necessary.
REFER to Section 205 - 01 .
z Damaged or worn
differential ring and
pinion. z
INSPECT the differential ring
and pinion for damage.
CARRY OUT the Checking
Tooth Contact Pattern and
Condition of the Ring and
Pinion component test in this
section. REPAIR or INSTALL
a new differential ring and
pinion as necessary. REFER
to Section 205 - 02A for Ford
7.5 rear axles or Section 205 -
02B for Ford 8.8 integral
axles.
z Planetary gears
nicked or chipped. z
CHECK the planetary gears
for damage. INSTALL new
components as necessary.
REFER to Section 307 - 01 .
z Whistle— noise
is high pitched,
constant.
Changes in
pitch with
throttle position z
Hydraulic pressure in
the main control. z
INSPECT the main control.
REPAIR or INSTALL new
components as necessary.
REFER to Section 307 - 01 .
z Incorrect band/clutch
apply pressure. z
CARRY OUT the line
pressure tests. REPAIR or
INSTALL components 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 Clunk— occurs
when shifting
from PARK to
a drive or
reverse
position z
Damaged powertrain
mounts. z
INSPECT the powertrain
mounts for damage. INSTALL
new mounts as necessary.
z Damaged or worn
pinion bearings. z
CHECK for abnormal bearing
play or roughness. INSTALL
new bearings as necessary.
REFER to Section 205 - 02A
for Ford 7.5 rear axles or
Section 205
- 02B for Ford 8.8
integral axles.
z Worn or galled
driveshaft slip yoke
splines. z
CLEAN and INSPECT the
splines of the yoke. INSTALL
a new slip yoke as necessary.
REFER to Section 205 - 01 .
z Worn friction
elements or
excessive clutch pack
end plate play. z
INSPECT the transmission
for wear. CHECK that all end
play and clearances are
within specification. REPAIR
or INSTALL new components
as necessary. REFER to
Section 307 - 01 . Klj . 46 ba
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z
Is the runout within specifications? persists,GO to
K8 .
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
K8 .
K8 CHECK FOR VIBRATION FROM THE FRONT OF THE
VEHICLE WARNING: If only one drive wheel is allowed to
rotate, speed must be limited to 55 km/h (34 mph) using
the speedometer reading, since actual wheel speed will
be twice that indicated on the speedometer. Exceeding a
speed of 55 km/h (34 mph) or allowing the drive wheel to
hang unsupported can result in tire disintegration or
differential failure, which can cause serious personal
injury and extensive vehicle damage.
z 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.
z Is the vibration present? Yes
SUBSTITUTE known
good wheel and tire
assemblies as necessary.
TEST the system for
normal operation.
No
GO to
K9 .
K9 CHECK FOR VIBRATION FROM THE REAR OF THE
VEHICLE WARNING: If only one drive wheel is allowed to
rotate, speed must be limited to 55 km/h (34 mph) using
the speedometer reading, since actual wheel speed will
be twice that indicated on the speedometer. Exceeding a
speed of 55 km/h (34 mph) or allowing the drive wheel to
hang unsupported can result in tire disintegration or
differential failure, which can cause serious personal
injury and extensive vehicle damage.
z Chock the front wheels.
z Raise and support the rear end of the vehicle so that the rear
wheel and tire assemblies can spin.
z Engage the drivetrain and carefully accelerate the drive
wheels while checking for vibration.
z Is the vibration present? Yes
GO to
K10 .
No
TEST the system for
normal operation. K10 CHECK THE DRIVETRAIN
WARNING: If only one drive wheel is allowed to
rotate, speed must be limited to 55 km/h (34 mph) using
the speedometer reading, since actual wheel speed will
be twice that indicated on the speedometer. Exceeding a
speed of 55 km/h (34 mph) or allowing the drive wheel to
hang unsupported can result in tire disintegration or
differential failure, which can cause serious personal
injury and extensive vehicle damage.
z Remove the rear wheel and tire assemblies. Refer to the Yes
CHECK/TEST the
drivetrain and driveline
components. TEST the
system for normal
operation.
No
SUBSTITUTE known
good wheel and tire Klj . 60 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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