Open Differential
A standard differential design that splits torque equally between wheels but allows them to rotate at different speeds during turns.
An open differential is the most common type of differential found in passenger vehicles. Its primary function is to transmit engine torque to the drive wheels while allowing them to rotate at different speeds. This speed difference is essential when cornering, as the outer wheel must travel a longer distance around the curve than the inner wheel. Without a differential, the tires would scrub, slide, and bind during turns.
The main drawback of an open differential is its behavior on low-traction surfaces. An open differential always splits engine torque equally (50/50) between the left and right wheels. However, the maximum torque it can deliver is limited by the wheel with the least traction. If one wheel is on ice or mud, it will spin freely with little resistance, and the opposite wheel on dry pavement will receive no torque, leaving the vehicle stuck.
Symptoms of open differential issues include whining or howling noises from the rear axle (indicating worn pinion or carrier bearings) and metallic clunking when shifting. Diagnostics involve checking the differential gear oil for metal debris and inspecting the gear teeth for wear. Servicing an open differential typically involves replacing worn bearings and setting correct backlash.