Chuckle

Chuckle is a particular rattling noise that sounds like a stick against the spokes of a spinning bicycle wheel. It occurs while decelerating from 64 Km/h (40 mph) and can usually be heard all the way to a stop. The frequency varies with the speed of the vehicle.

Chuckle that occurs on the coast driving phase is usually caused by excessive clearance between the differential gear hub and the differential case bore. It can also be caused by a damaged tooth on the coast side of the pinion or ring gear.

Any damage to a gear tooth on the coast side can cause a noise identical to chuckle. Even a very small tooth nick or ridge on the edge of a tooth is enough to cause the noise.

You can often correct this condition and eliminate the noise simply by cleaning up the gear tooth nick or ridge with a small grinding wheel. If the cleaned up or damaged area is larger than 3.2 mm (1/8 inch), it is advisable to replace the gearset.

WARNING: ALWAYS WEAR SAFETY GOGGLES. IF SOLVENT OR COMPRESSED AIR GETS IN YOUR EYES, SEVERE IRRITATION OR PERMANENT INJURY SUCH AS BLINDNESS COULD RESULT. SEEK MEDICAL ATTENTION IMMEDIATELY.

To check the differential 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, the differential ring gear and pinion must be replaced. If there is metal broken loose, the rear axle housing must also be cleaned to remove particles that could cause damage later. Any other damaged parts in the rear axle housing must be replaced.