Drive Axles, Bearings and Joints: Description and Operation
The rear drive axle operates as follows:^ It receives power from the engine through the transmission and driveshaft.
^ The pinion gear rotates the differential case through engagement with the ring gear which is bolted to the differential case outer flange.
^ Inside the differential case, two differential pinion gears are mounted on the differential pinion shaft which is pinned to the differential case.
^ These differential pinion gears are engaged with the axle shaft to which the axle shafts are splined.
^ 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 gear to roll on the slower-turning differential side gear to allow differential action between the two axle shafts.