Another gear noise that is common in differentials is the chuckle. A chuckle is a low "heh-heh" sound that occurs
when gears are worn to the point where there is excessive clearance between the pinion gear and the ring gear.
Chuckle sounds occur most often in the decelerating mode, particularly below 40 mph (65 km/h). As the vehicle
decelerates, the chuckle also slows and can be heard all the way to a stop.