Ford Mustang (1999-2004) Service Manual: Chuckle
Chuckle that occurs on the coast driving phase is usually caused by excessive clearance between the differential gear hub and the differential case bore.
Damage to a gear tooth on the coast side can cause a noise identical to a chuckle. A very small tooth nick or ridge on the edge of a tooth can cause the noise.
Clean the gear tooth nick or ridge with a small grinding wheel. If the damaged area is larger than 3.2 mm (1/8 inch), install a new gearset.
To check the ring gear and pinion, remove as much lubricant as possible from the gears with clean solvent. Wipe the gears dry or blow them dry with compressed air. Look for scored or damaged teeth.
Also look for cracks or other damage.
If either gear is scored or damaged badly, install a new ring gear and pinion.

If metal has broken loose, the axle housing must be cleaned to remove particles that will cause damage. At this time, any other new parts in the axle housing must also be installed, if necessary.
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. ...
Knock
Knock, which can occur on all driving phases, has several causes including
damaged teeth or gearset.
In most cases, one of the following conditions will occur:
1. A gear tooth damaged on the drive s ...
Other materials:
Reservoir
Removal
1. Remove the LF wheel and tire. Refer to Section.
2. Position the front portion of the LF inner splash shield aside.
3. WARNING: Windshield washer solution contains methanol, which is
poisonous.
Observe all cautions and warnings indicate ...
Supplementary Restraints System
PRINCIPLES OF OPERATION
WARNING: Airbags do not inflate slowly or gently, and the risk
of injury from a deploying airbag is the greatest close to the trim
covering the airbag module.
WARNING: All occupants of your vehicle, including the driver,
should always p ...
Inspection and Verification
NOTE: If any concerns are noted with the speedometer, stoplamps, or
horn, address those concerns
by referring to their associated sections before continuing speed control
diagnosis.
1. Verify the customer concern by operating the speed control system.
2. Vi ...
