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:
Cylinder Head (Disassembly and Assembly of Subassemblies)
Special Tool(s)
Compressor, Valve Spring
303-381(T91P-6565-A)
Compressor Spacer, Valve
Spring
303-382 (T91P-6565-AH)
Installer, Valve Stem Oil Seal
303-383 (T91P-6571-A)
Material
Item
Specification
Sup ...
Arm - Lower
Removal
CAUTION: Suspension fasteners are critical parts because they affect
performance of vital
components and systems and their failure can result in major service expense. A
new part with
the same part number or an equivalent part must be installed, if i ...
Underbody Misalignment Check
Underbody Dimensions
1. Underbody dimensions tolerances are +- 3.175 mm (0.125 in). Reference
dimensions are not
controlled dimensions. Reference points are +- 4.76 mm (0.1875 in). All underbody
dimensions
are detailed to the centerline of existin ...
