Most drivers do not spend much time thinking about the complexity of a vehicle's turning capability. Keeping the wheels synchronized with each other is the duty of the rear differential. Keeping this assembly lubricated is essential for proper functioning.
When a car turns a corner, the wheels on the inside of the curve spin more slowly than the wheels on the outside of the curve. This simple function is achieved by the rear differential and the gear ratios associated with it.
Rear differential fluid is actually the same fluid as the transmission, since they share common portions of the vehicle where the fluid is exchanged. Hence, when the transmission fluid is changed, or flushed, every 30,000 miles, it is also changing the rear differential fluid as well.
Every vehicle is different, so referring to the specific owner's manual for the individual car is imperative when determining service intervals. Keeping up with car maintenance is key for a long vehicle lifespan.
