Cone Clutch Limited Slip Differential

A cone clutch limited slip differential uses the friction produced by cone-shaped axle gears to provide improved traction (fig. 5-18). These cones fit behind and are splined to the axle shafts. With the axles splined to the cones. the axles tend to rotate with the differential case.

Coil springs are situated between the side gears to wedge the clutches into the differential case. Under rapid acceleration or when one wheel loses traction. the differential pinion gears, as they drive the cones, push outward on the cone gears. This action increases friction between the cones and case, driving the wheels with even greater torque.

When a vehicle goes around a comer, the inner drive wheel must slow down. The unequal speed between the side gears will cause the side gear pinions to walk around the side gears. This walking action causes the outer axle shaft to rotate faster than the differential case. Because the cones have spiral grooves cut into their clutch surfaces, the inner cone will draw itself into the case and lock tight and the outer cone clutch will back itself out of the case. This action allows the outer drive axle to free wheel. The end result is the majority of the engine torque is sent to the inner drive wheel.

IFFERENTIAL SERVICE AND MAINTENANCE

Differentials in a properly operated vehicle seldom cause any maintenance problems. By maintaining the proper lubrication level and occasionally changing a seal or gasket, the assembly will normally last as long as the vehicle.

The first hint of existing trouble is generally an unusual noise in the axle housing. To diagnose the trouble properly, you must determine the source of the noise and under what operating conditions the noise is most pronounced. Defective universal joints, rough wheel bearings, or tire noises may be improperly diagnosed by an inexperienced mechanic as differential trouble.

Some clue may be gained as to the cause of trouble by noting whether the noise is a growl, hum, or knock; whether it is heard when the vehicle is operating on a straight road, or on turns only; and whether the noise is most noticeable when the engine is driving the vehicle or when it is coasting with the vehicle driving the engine.

Figure 5-18. - Cone clutch limited slip differential.