Which Axle Drives an Eight-Wheeler?
2 Answers
An eight-wheeler is rear-axle driven. Below are relevant details: 1. Drive Axle: Located at the end of the drivetrain, it alters the speed and torque from the transmission before transmitting them to the driving wheels. The drive axle typically consists of the main reducer, differential, wheel drive mechanism, and axle housing. Steering drive axles also include constant-velocity universal joints. Additionally, the drive axle bears vertical forces, longitudinal and lateral forces between the road surface and the frame/body, as well as braking torque and reaction forces. 2. Differential: Eight-wheelers generally feature an interaxle differential lock. When the interaxle lock engages the center axle differential, both the center and rear axles drive simultaneously; otherwise, only the rear axle provides propulsion.
I've been driving heavy trucks for decades, and vehicles like the 8x4 trucks derive all their power from the rear axle—more specifically, the rear two axles are the primary driving force. Why this design? It's simple: the rear of the vehicle carries the heaviest load, and rear-wheel drive provides strong pushing force and traction. For example, when hauling heavy loads on muddy or construction sites, the front wheels can't pull effectively, but rear-wheel drive ensures steady progress and prevents wheel spin. If there's a drive issue, the truck might get stuck, and I'd have to stop to check the differential oil or universal joint wear. Regular maintenance is crucial—frequent oil changes and inspecting the driveshaft ensure safe driving. This layout is quite reliable; driving it feels like an ox pulling a cart—slow but powerful. Remember, understanding the structure and choosing the right drive system makes driving more worry-free and efficient.
