Front differential with helical LSD

CONSTRUCTION The components of the helical LSD are side gears, four sets of pinion gear A and B, four thrust washers and a center washer. Those component parts are encased within the differential case and a crown gear is bolted to the flange of the differential case. The shape of all gear tooth is HELICAL type. Pinion gear A Center washer Side gear LH Differential case Crown gear Thrust washer Side gear RH Pinion gear B

DIFFERENTIAL FUNCTION When the vehicle is moving down a straight road, the left and right wheels are turning at the same speed, so there is no difference in the rotational speed of the left and right side gears. Therefore, pinion gears do not rotate against other gears and all component parts rotate as a unit.

While a vehicle turns, producing a difference in rotational speed between the left and right side gears, the pinion gear A and B start to rotate. This is because the pinion gear A or B must revolve around the slower-turning side gear. This means that they carry additional rotary motion to the faster-turning side gear.

LSD FUNCTION When one wheel attempts to spin, the pinion gears start to rotate and there are three types of friction forces produced in the differential case. 1. The friction between pinion gear tooth and differential case 2. The friction between pinion gear end surface and differential case 3. The friction between LH and RH Side gears 1 2 3

These friction forces work against rotation of the two side gears, pinion gear A and pinion gear B, and the speed differences of the side gears are limited. As a result, the input torque from the crown gear is distributed along the left and right side gears according to the sum of three types of friction forces.