FORD MUSTANG 2003 Workshop Manual

Installation
1. WARNING: When a wheel is installed, always remove any corrosion, dirt or foreign
material present on the mounting surfaces of the wheel and the surface of the wheel hub,
brake drum or brake disc that contacts the wheel. Installing wheels without correct
metal- to-metal contact at the wheel mounting surfaces can cause the wheel nuts to
loosen and the wheel to come off while the vehicle is in motion, causing loss of control.
Position the wheel and tire on the vehicle.
2. CAUTION: Failure to tighten the wheel nuts in a star pattern can result in high brake
disc runout, which will speed up the development of brake roughness, shudder and
vibration.
Install the wheel nuts hand- tight, then lower the vehicle. Tighten the wheel nuts to specification
in a star- pattern sequence.
3. Install the center cap, if so equipped. Klj . 2 ba
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SPECIFICATIONS
All driveshaft and pinion angles point downward.
a
Service refill capacities are determined by filling the axle 6.3 mm (0.25 in [1/4 in]) to 14.3 mm (0.57 in
[5/16 in]) below the bottom of the filler hole. The vehicle must be on a level surface.
b Friction Modifier
SECTION 205-
00: Driveline System — General Information 2003 Mustang Workshop Manual Driveline Angles @ Curb Specifications
Engine (L) Engine Angle (Deg) Driveshaft Angle (Deg) Pinion Angle (Deg)
3.8 4.0 2.95 0.55
4.6 (2V) 4.0 3.61 0.55
General Specifications Item Specification
Axle Capacities and Lubricant Specifications
7.5 inch rear axle
a 1.5 liters (3.5 pints)
8.8 inch rear axle
a
(base and GT vehicles) 1.9 liters (4.0/3.75 pints)
Traction-
Lok b 118 ml (4 oz)
Premium Rear Axle Lubricant
XY-
80 W90- QL WSP-
M2C197- A Additive Friction Modifier
C8AZ-
19B546- A EST-
M2C118- A Premium Long-
Life Grease
XG -1-C ESA-
M1C75- B Klj . 1 ba
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DIAGNOSIS AND TESTING
Driveline System
SECTION 205-
00: Driveline System — General Information 2003 Mustang Workshop Manual Special Tool(s)
Clamp Plate
205-
320 (T92L-4851- C) Clutch Housing Alignment
Adapter
308-
021 (T75L-4201- A) Companion Flange Holding
Tool
205-
126 (T78P-4851- A) Companion Flange Runout
Gauge
205-
319 (T92L-4851- B) Dial Indicator with Bracketry
100-
002 (TOOL- 4201-C) or
equivalent Dial Indicator/Magnetic Base
100-
D002 (D78P-4201- B) or
equivalent Vibration Analyzer
100-
F027 (014- 00344) Traction-Lok® Torque Tool
205- 022 (T66L-4204- A) 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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Repair the axle as necessary. Make sure the axle lubricant is at the correct level. Refer to
Specifications in this section.
Axle Vent
NOTE:
If a plugged vent cannot be cleared, install a new one.
A plugged vent will cause excessive seal lip wear due to internal pressure buildup. If a leak occurs,
check the vent. Make sure the vent hose is not kinked. Remove the hose from the vent nipple and
clear the hose of any foreign material. While the hose is removed, pass a length of mechanics wire in
and out of the vent to clean it. Connect the hose when done.
Flange Yoke Seal
Leaks at the axle drive pinion seal originate for the following reasons:
zSeal was not correctly installed.
z Poor quality seal journal surface.
Any damage to the seal bore (dings, dents, gouges, or other imperfections) will distort the seal casing
and allow leakage past the outer edge of the axle drive pinion seal.
The axle drive pinion seal can be torn, cut, or gouged if it is not installed carefully. The spring that
holds the axle drive pinion seal against the pinion flange may be knocked out and allow leakage past
the lip.
The rubber lips can occasionally become hard (like plastic) with cracks at the oil lip contact point. The
contact point on the pinion flange may blacken, indicating excessive heat. Marks, nicks, gouges, or
rough surface texture on the seal journal of the pinion flange will also cause leaks.
When a seal leak occurs, install a new seal and check the vent and the vent hose to make sure they
are clean and free of foreign material.
Axle Shaft Seals
Axle shaft oil seals are susceptible to the same kinds of damage as axle drive pinion seals if incorrectly
installed. The seal bore must be clean and the lip handled carefully to avoid cutting or tearing it. The
axle shaft journal surface must be free of nicks, gouges, and rough surface texture.
Differential Seals
Refer to Section 205 - 02A or
Section 205 - 02B .
Analysis of Vibration WARNING: A vehicle equipped with a Traction- Lok® differential will always have both
wheels driving. If only one wheel is raised off the floor and the rear axle is driven by the engine,
the wheel on the floor could drive the vehicle off the stand or jack. Be sure both rear wheels are
off the floor.
Few vibration conditions are caused by the rear axle. On a vibration concern, follow the diagnosis
procedure in Section 100 - 04 unless there is a good reason to suspect the axle.
Tires Klj . 3 ba
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WARNING: Do not balance the wheels and tires while they are mounted on the vehicle.
Possible tire disintegration/differential failure could result, causing personal injury/extensive
component damage. Use an off- vehicle wheel and tire balancer only.
Most vibration in the rear end is caused by tires or driveline angle.
Vibration is a concern with modern, high- mileage tires if they are not "true" both radially and laterally.
They are more susceptible to vibration around the limits of radial and lateral runout of the tire and
wheel assembly. They also require more accurate balancing. Wheel and tire runout checks, truing and
balancing are normally done before axle inspection. Refer to Section 204 - 04 .
Driveline Angle
Driveline angularity is the angular relationship between the engine crankshaft (6303), the driveshaft,
and the rear axle pinion. Factors determining driveline angularity include ride height, rear spring, and
engine mounts.
Driveline Angle
An incorrect driveline (pinion) angle can often be detected by the driving condition in which the
vibration occurs.
zA vibration during coastdown from 72 to 56 km/h (45 to 35 mph) is often caused by an
excessive U-joint angle at the axle (pinion nose downward).
z A vibration during acceleration, from 56 to 72 km/h (35 to 45 mph) may indicate an excessive U- joint angle at the axle (pinion nose upward). Item Description
1 Bottom of the frame
2 Engine crankshaft centerline
3 Engine angle
4 Driveshaft and coupling shaft centerline
5 Driveshaft and coupling shaft angle
6 Rear axle pinion centerline
7 Axle pinion angle Klj . 4 ba
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When these conditions exist, check the driveline angles as described in the General Procedures
portion of this section.
If the tires and driveline angle are not the cause, carry out the NVH tests to determine whether the
concern is caused by a condition in the axle. Refer to
Section 100 - 04 .
Universal Joint (U- Joint) Wear
Place the vehicle on a frame hoist and rotate the driveshaft 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 .
Wheel Hub or Axle Flange Bolt Circle Runout
NOTE: The brake discs must be removed to carry out all runout measurements.
1. Position the special tool perpendicular to the wheel hub or axle flange bolt, as close to the hub or flange face as possible. Zero the indicator to allow the pointer to deflect either way.
2. Rotate the hub or flange until the next bolt is contacted. Record the measurement and continue until each bolt is checked. The difference between the maximum and minimum contact readings
will be the total wheel hub or axle flange bolt pattern runout. The runout must not exceed 0.38
mm (0.015 inch).
Pilot Runout
1. Position the special tools as close to the hub or axle flange face as possible. Zero the indicator to allow the pointer to deflect either way.
2. Rotate the hub or flange one full turn and note the maximum and minimum readings. The difference between the maximum and minimum readings will be the total pilot runout. Pilot
runout must not exceed 0.15 mm (0.006 inch).
Wheel Hub or Axle Flange Face Runout Klj . 5 ba
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NOTE:
If the axle shaft assembly is removed, check runout of the shaft itself. The forged (unmachined)
part of the shaft is allowed to have as much as 3.0 mm (0.120 inch) runout. This alone will not cause a
vibration condition.
1. Position the special tool on the wheel hub or axle flange face, as close to the outer edge as possible. Zero the indicator to allow the pointer to deflect either way.
2. Rotate the hub or flange one full turn and note the maximum and minimum readings. The difference between the maximum and minimum readings will be the total face runout. The
runout must not exceed 0.127 mm (0.005 inch).
Drive Pinion Stem and Pinion Flange
Check the pinion flange runout when all other checks have failed to show the cause of vibration.
One cause of excessive pinion flange runout is incorrect installation of the axle drive pinion seal.
Check to see if the spring on the seal lip has been dislodged before installing the ring gear and pinion.
Axle Noise
NOTE: Before disassembling the axle to diagnose and correct gear noise, eliminate the tires, exhaust,
trim items, roof racks, axle shafts and wheel bearings as possible causes. Follow the diagnostic
procedures in Section 100 - 04 .
The noises described as follows usually have specific causes that can be diagnosed by observation as
the unit is disassembled. The initial clues are the type of noise heard during the road test.
Gear Howl and Whine
Howling or whining of the ring gear and pinion is due to an incorrect gear pattern, gear damage or
incorrect bearing preload.
Bearing Whine
Bearing whine is a high- pitched sound similar to a whistle. It is usually caused by worn/damaged
pinion bearings, which are operating at driveshaft speed. Bearing noise occurs at all driving speeds.
This distinguishes it from gear whine which usually comes and goes as speed changes.
As noted, pinion bearings make a high- pitched, whistling noise, usually at all speeds. If however there
is only one pinion bearing that is worn/damaged, the noise may vary in different driving phases. If
pinion bearings are scored or damaged or there is a specific pinion bearing noise, new pinion bearings
must be installed. A worn/damaged bearing will normally be obvious at disassembly. Examine the
large end of the rollers for wear. If the pinion bearings original blend radius has worn to a sharp edge, a new pinion bearing must be installed. Klj . 6 ba
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