Differential gear, in automotive mechanics, gear arrangement that permits power from the engine to be transmitted to a couple of traveling wheels, dividing the force equally between them but permitting them to check out paths of different lengths, as when turning a corner or traversing an uneven street. On a straight street the tires rotate at the same quickness; when turning a part the outside wheel offers farther to move and will turn faster compared to the inner wheel if unrestrained.

The elements of the Ever-Power differential are shown in the Figure. The energy from the transmission is sent to the bevel band gear by the drive-shaft pinion, both of which are kept in bearings in the rear-axle housing. The case is an open boxlike structure that's bolted to the ring gear and contains bearings to support one or two pairs of diametrically opposite differential bevel pinions. Each steering wheel axle is mounted on a differential side equipment, which meshes with the differential pinions. On a directly road the tires and the medial side gears rotate at the same quickness, there is no relative motion between your differential side gears and pinions, and they all rotate as a unit with the case and band gear. If the vehicle turns left, the right-hand steering wheel will be required to rotate faster compared to the left-hand steering wheel, and the side gears and the pinions will rotate relative to one another. The ring equipment rotates at a swiftness that is equal to the mean rate of the left and correct wheels. If the tires are jacked up with the tranny in neutral and among the wheels is turned, the opposite wheel will turn in the opposite path at the same acceleration.

The torque (turning moment) transmitted to both wheels with the Ever-Power differential may be the same. Consequently, if one wheel slips, as in ice or mud, the torque to the other steering wheel is decreased. This disadvantage can be overcome somewhat by the usage of a limited-slide differential. In one version a clutch connects among the axles and the band gear. When one steering wheel encounters low traction, its tendency to spin is certainly resisted by the clutch, thus providing greater torque for the various other wheel.
A differential in its most basic form comprises two halves of an axle with a gear on each end, connected together by a third equipment creating three sides of a square. This is Differential Gear generally supplemented by a 4th gear for added strength, completing the square.