Ford 2003 Mustang Workshop Manual page 274

crayon or chalk.
6. While holding the crayon or chalk against the tire, rotate the wheel slowly in the opposite
direction until the feeling of driving the rear axle is encountered again.
7. Measure the length of the crayon or chalk mark on the tire.
If the length of the mark is 25.4 mm (1 inch) or less, the rear axle backlash is within
allowable limits.
If the chalk mark is greater than 25.4 mm (1 inch), check for these conditions:
Elongation of the differential pinion shaft and holes in the differential case (4204).
Missing differential pinion thrust washer (4230) or differential side gear thrust
washer (4228).
Galling of the differential pinion shaft (4211) and bore.
Excessive ring gear and pinion backlash. Follow the procedure for the type of rear
axle to check backlash.
Axle Shaft Bearing Noise
Axle bearing shaft noise is similar to gear noise and differential pinion bearing whine. Axle shaft
bearing noise will usually distinguish itself from gear noise by occurring in all driving modes (drive,
coast, and float), and will persist with the transmission in NEUTRAL while the vehicle is moving at the
speed in which the concern is occurring. If the vehicle makes this noise, remove the suspect axle
shaft, install a new bearing and a new axle seal. Re-evaluate the vehicle for noise before removing any
internal components.
Bearing Rumble
Bearing rumble sounds like marbles being tumbled. This condition is usually caused by a
worn/damaged wheel bearing. The lower pitch is because the wheel bearing turns at only about one-
third of the driveshaft speed. Wheel bearing noise also may be high-pitched, similar to gear noise, but
will be evident in all four driving modes.
Symptom Chart
Symptom Chart
Condition
Traction-Lok®
does not work in
snow, mud or on
ice
Lubricant leaking
from the pinion
seal, axle shaft oil
seals
Differential side
gears/pinion
gears are scored
Possible Sources
Differential.
Vent.
Damage in the
seal contact area
or damaged or
worn seal.
Insufficient
lubrication.
Incorrect or
contaminated
Action
CARRY OUT the Traction-
Lok® Differential Operation
Check in this section. REPAIR
as necessary. REFER to
Section 205-02A or Section
205-02B .
CLEAN the axle housing vent.
INSTALL a new seal if
damage is found.
INSTALL new gears. REFER
to Section 205-02A or Section
205-02B . FILL the axle to
specification.
INSTALL new gears. REFER
to Section 205-02A or Section