Differential Assembly: Description and Operation

Rear Drive Axle and Differential





The rear axle drive pinion receives power from the engine through the transmission and driveshaft. The drive pinion gear rotates the differential drive gear which is bolted to the differential housing outer flange. Inside the differential housing, two differential pinion gears are mounted on a differential shaft which is pinned to the differential housing. These differential pinion gears are engaged with the differential side gears to which the axle shafts are splined. As the differential gear turns, it rotates the axle shafts and rear wheels.

When it is necessary for one wheel and axle shaft to rotate faster than the other, the faster turning differential side gear causes the differential pinion gears to roll on the slower turning differential side gear. This allows differential action between the two axle shafts.