Insufficient oil in the rear axle can accelerate gear wear, and during driving, it may cause the vehicle to seize up or the rear wheels to lock. The functions of the rear axle are as follows: 1. If the front axle is not a drive axle, then the rear axle serves as the drive axle. In this case, besides bearing the load, it also functions in driving, deceleration, and differential action. For four-wheel-drive vehicles, a transfer case is usually installed in front of the rear axle. 2. The front and rear axles refer to the parts of the front and rear wheel axles. The front axle includes components such as shock absorber springs, steering gear, and balance shafts. The rear axle also includes the drive shaft and transmission gears. For multi-axle trucks, the rear can be divided into driven rear axles and non-driven rear axles. A non-driven rear axle is not connected to the drive shaft and does not belong to the driving wheels. This configuration is typically found in heavy-duty trucks and tractor heads with three or more axles. 3. Rear axles are classified based on their suspension types into solid axles and independent axles. Solid axles are paired with non-independent suspensions, such as leaf spring suspensions, while independent axles are paired with independent suspensions, such as MacPherson suspensions. The large bulge at the center of the rear axle is present only when the rear axle is a drive axle, as it houses the reduction gears and differential mechanism. Rear axles that are follower axles generally do not have this bulge. 4. Based on their functions, axles can be categorized into drive axles, steering axles, support axles, and steering drive axles.
