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:
Using sync with your phone
Hands-free calling is one of the main features of SYNC. While the system
supports a variety of features, many are dependent on your cellular
phone’s functionality. At a minimum, most cellular phones with Bluetooth
wireless technology support the following fu ...
Vibration When Brakes are Applied
For vibration concerns when brakes are applied, perform the following
procedure.
Visually inspect:
tire condition and pressure.
suspension bushings and ball joints.
Correct as necessary.
1. Verify and isolate the concern. Brake roughness can be felt in: ...
Getting assistance outside the U.S. And Canada
Before exporting your vehicle to a foreign country, contact the
appropriate foreign embassy or consulate. These officials can inform you
of local vehicle registration regulations and where to find unleaded fuel.
If you cannot find unleaded fuel or can only ge ...
