Operation

The rear axle drive pinion receives its 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 case outer flange.

Inside the case, two differential pinion gears are mounted on the differential pinion shaft which is pinned (with lock bolt) to the case. These pinion gears are engaged with the side gears, to which the axle shafts are splined. Therefore, as the differential case 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 side gear causes the pinions to roll on the slower turning side gear to allow differential action between the two axle shafts.