warning FORD MUSTANG 2003 Owner's Manual

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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If no improvement is noted, rotate the clamps in opposite directions, equal distances from the best
position determined in Step 8. Separate the clamp heads about 13 mm (1/2 inch) and recheck for
vibration at the road speed.
Repeat the process with increasing separation until the best combination is found or the vibration is
reduced to an acceptable level.
10. Install the wheels and road test (vibration noticeable on the hoist may not be evident during the road test). If the vibration is still not acceptable, install a new axle driveline vibration damper
first, if so equipped. If the vibration is still not acceptable, refer to Section 205 - 02A or
Section 205 - 02B for differential case and ring gear runout checks.
Driveshaft Vibrates 1. Road test the vehicle to determine the critical vibration points. Note the road speed, the engine RPM, and the shift lever positions at which the vibration occurs.
2. Stop the vehicle, place the transmission lever in neutral and run the engine through the critical speed ranges determined in Step 1.
3. If no vibration is felt, balance the driveshaft. Refer to Driveline Vibration in this section.
Traction- Lok® Differential Operation Check
A Traction-Lok® differential can be checked for correct operation without removing it from the rear axle
housing.
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 Klj . 14 ba
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Remove the axle shafts. For additional information, refer to
Axle Shaft in this section.
3. Wipe the lubricant from the internal working parts and inspect the parts for wear and damage.
4. Rotate the differential assembly to check for roughness indicating bearing/gear damage.
5. Using a suitable dial indicator and the special tool, measure and note the ring gear backface runout.
6. CAUTION: Mark the position and location of the bearing caps, as the arrows may
not be visible. Always install the bearing caps in their identical locations and positions.
Remove the bearing caps. 1. Remove the bolts.
2. Remove the bearing caps.
7. WARNING: Do not allow the differential assembly to fall. Failure to follow these
instructions may result in personal injury and component damage. CAUTION: Place a wood block between the pry bar and the differential housing Klj . 2 ba
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Remove the axle shafts. For additional information, refer to
Axle Shaft in this section.
3. Wipe the lubricant from the internal working parts and inspect the parts for wear and damage.
4. Rotate the differential assembly to check for roughness indicating bearing/gear damage.
5. Using a suitable dial indicator and the special tool, measure and note the ring gear backface runout.
6. CAUTION: Mark the position and location of the bearing caps, as the arrows may
not be visible. Always install the bearing caps in their identical locations and positions.
Remove the bearing caps. 1. Remove the bolts.
2. Remove the bearing caps.
7. WARNING: Do not allow the differential assembly to fall. Failure to follow these
instructions may result in personal injury and component damage. CAUTION: Place a wood block between the pry bar and the differential housing Klj . 2 ba
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3.
CAUTION: Do not damage the threads in the bolt holes.
Insert a punch in the bolt holes, and drive off the ring gear.
4. Using the special tools, remove the differential bearings (4221), if necessary.
5. Remove the bolt and the differential pinion shaft (4211).
6. WARNING: Due to the spring tension, use care when removing the differential Klj . 2 ba
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36.
WARNING: The differential clutch spring (4214) is under tension. Remove the spring
carefully. Failure to follow these instructions may result in personal injury.
Remove the differential clutch spring.
37. Remove the differential gears. 1. Remove the two differential pinion gears (4215) and pinion thrust washers (4230).
2. Remove the two differential side gears (4236) with the clutch packs (4947) and the shims and tag them "left" and "right."
38. CAUTION: Keep the differential clutch packs in order. Do not mix them. Always
reassemble them in the same sequence.
Remove the differential clutch packs and shims from the differential side gears.
zClean and inspect the remaining differential components for wear and damage. Install
new parts as necessary. Klj . 14 ba
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z
Do not drop assembled halfshafts. The impact will cut the boots from the inside without
evidence of external damage.
z Inspect all machined surfaces and splines for damage.
Wheel and Tire Balancing, Rear
WARNING: Do not balance the rear wheels and tires while mounted on the vehicle.
Possible tire disintegration, differential or halfshaft failure can result, causing personal injury
or extensive component damage. Use an off- vehicle wheel and tire balancer only.
Hoisting
CAUTION: Use a frame- contact hoist only. Vehicle or component damage can result if
other types of hoists are used.
Never raise the vehicle using the halfshafts as lift points.
Undercoating and Rustproofing
During undercoating and rustproofing procedures, protect the boots from the coating materials.
Foreign materials on the rubber boots will cause extreme advanced wear. Klj . 3 ba
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DIAGNOSIS AND TESTING
Brake System
Refer to Wiring Diagrams Cell
60 , Instrument Cluster for schematic and connector information.
Refer to Wiring Diagrams Cell 97 , Daytime Running Lamps for schematic and connector information.
Inspection and Verification WARNING: Use of any other than the approved DOT 3 brake fluid will cause permanent
damage to brake components and will render the brakes inoperative.
WARNING: Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with
eyes. Wash hands thoroughly after handling. If brake fluid contacts eyes, flush eyes with
running water for 15 minutes. Get medical attention if irritation persists. If taken internally,
drink water and induce vomiting. Get medical attention immediately.
CAUTION: Do not spill brake fluid onto painted surfaces. If spilled, wipe up immediately.
NOTE: Always check the fluid level in the brake master cylinder reservoir (2K478) before performing
the test procedures. If the fluid level is not at the correct level, add High Performance DOT 3 Brake
Fluid C6AZ- 19542-AB or equivalent DOT 3 fluid meeting Ford specification ESA- M6C25-A.
NOTE: Prior to performing any diagnosis, make sure the brake warning indicator is functional. For
additional information, refer to Section 413 - 01 .
The first indication that something may be wrong in the brake system is a change in the feeling through
the brake pedal (2455). The brake warning indicator in the instrument cluster and the brake fluid level SECTION 206-
00: Brake System — General Information 2003 Mustang Workshop Manual Special Tool(s)
73 Digital Multimeter
105-
R0051 or Equivalent ABS Brake and Pressure Test
Kit
107-
02350 or Equivalent Tire and Wheel Runout Gauge
Set
134-
00199 or Equivalent Klj . 1 ba
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not machine a new brake disc.
7. For vehicles with a two- piece hub and brake disc assembly:
z Match-mark before disassembly.
z Remove the brake disc.
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.
8. 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 on- vehicle brake lathe, machine the brake discs. Follow the manufacturer's instructions.
After machining, make sure the brake disc still meets the thickness specification.
9. Using a dial indicator, verify that the brake disc lateral runout is now within vehicle specification.
10. Remove any metal chips.
11. Remove the hub adapter.
12. Remove any remaining metal chips from the machining operation.
13. CAUTION: Do not carry out this step on rear drum- in-hat brake discs.
For vehicles with a two- piece hub and a non drum- in-hat 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 High Temperature Nickel Anti- Seize Lubricant F6AZ-9L494-AA to the mounting
surfaces.
z Using the match- marks, mount the brake disc on the hub.
14. Install the caliper and check brake operation.
Symptom Chart Symptom Chart
Condition
Possible Sources Action
z The Brakes Pull or
Drift z
Tire air pressure.
z Wheel alignment.
z Brake pads.
z Brake components.
z Suspension
component. z
Go To Pinpoint Test A .
z The Red Brake
Warning Indicator Is z
Instrument cluster.
z Circuit. z
Go To Pinpoint Test B . Klj . 4 ba
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