Racing Differentials & Components

The simplest form of a typical open differential is a mechanical gear assembly designed to make the drive wheels rotate at different speeds when a four-wheeled vehicle is cornering. The outer wheel travels a longer distance on a wider turning radius, so it needs to rotate faster. Without the differential, the outer wheels would slip making the vehicle much harder to handle and drastically reducing the service life of rubber tires. The construction of the differential is fairly simple. A pinion sits on a driveshaft. It rotates a ring gear that holds two or more spider gears meshed with side gears on drive half shafts.

When the vehicle drives straight, spider gears are balanced, so they rotate side gears along with the ring. During cornering, spider gears start rotating thus splitting the speed of the ring and thus the torque from the engine between two drive shafts making the outer one rotate faster than its inner counterpart. Since engine power in this case mostly goes to the wheel with the least traction, the one getting on a slippery surface may start to rotate fast leaving the other one almost dead. To limit the independence between two drive half shafts, the clutch, cone, or hydraulic locking mechanisms are added to the construction.

Some manufacturers use electronic systems that detect spinning wheels without traction and send signals to partially engage brakes on that wheel to channel the engine’s power to the other wheel on solid ground. A hydraulic differential lock can be temporarily engaged in a difficult off-road situation when one of the drive wheels digs deeper into snow, mud, or sand. By installing a high-performance ring and pinion set with different gear ratio, racing enthusiasts can achieve the needed torque multiplication for faster acceleration on the street, strip, or track. Browse our digital shelves to find a huge assortment of premium racing differentials and related components, such as durable and lightweight differential cases, housings, rings and pinions, spider gears, and much more.