Rear Axles for this vehicle consist of the following components:
• | Differential axle housing |
• | Right and left axle tubes |
• | Right and left axle shafts |
A open differential has a set of 4 gears. Two are side
gears and 2 are pinion gears. Some differentials have more than 2 pinion
gears. Each side gear is splined to an axle shaft so that each axle shaft
turns when its side gear rotates. The pinion gears are mounted on a differential
pinion shaft, and the gears are free to rotate on this shaft. The pinion
shaft is fitted into a bore in the differential case and is at right angles
to the axle shafts. Power is transmitted through the differential as follows:
The drive pinion rotates the ring gear. The ring gear being bolted to the
differential case, rotates the case. The differential pinion, as it rotates
the case, forces the pinion gears against the side gears. When both wheels
have equal traction, the pinion gears do not rotate on the pinion shaft
because of input force on the pinion gear is equally divided between the
2 side gears. Therefore, the pinion gears revolve with the pinion shaft,
but do not rotate around the shaft itself. The side gears, being splined
to the axle shafts and in mesh with the pinion gears rotate the axle shafts.
If a vehicle were always driven in a straight line, the ring and pinion
gears would be sufficient. The axle shaft could be solidly attached to
the ring gear and both driving wheels would turn at equal speed. However,
if it became necessary to turn a corner, the tires would scuff and slide
because the differential allows the axle shafts to rotate at different
speeds. When the vehicle turns a corner, the inner wheel turns slower than
the out wheel and slows its rear axle side gear (as the shaft is splined
to the side gear). The rear axle pinion gears will roll around the slowed
rear axle side gear, driving the rear axle side gear wheel faster.