A beam axle, also known as a live axle, is a solid axle commonly used in the rear of rear-wheel-drive vehicles, trailers, and four-wheel-drive trucks. It is cost-effective but produces a heavy unsprung weight, affecting ride quality. While it can be raised to high-quality ride standards, it falls short of independent axles in cornering and bump hits. Some early vehicle designs used a beam axle at the front, and it continues to be used on semi trucks due to its strength.
A beam axle is a solid style of axle also called a live axle and is typically used in the rear of a rear wheel drive vehicle. This axle is also often found on trailers and in the front and rear of four-wheel drive trucks. Used primarily because of the low cost required to manufacture the axle, a beam axle does not produce as smooth a slide as other types of axles due to the very heavy unsprung weight it produces. Typically suspended by leaf spring suspension, the beam axle can also be suspended by coil springs and will occasionally use a panhard bar to maintain axle position between the chassis frame rails.
The beam axle has been mainly used in all kinds of cars and trucks produced. By placing rigidly mounted axle tubes in a differential, the beam axle creates a strong platform on which to build a vehicle. While not quite as smooth and doesn’t produce the ride quality of an independent rear axle, the beam axle can be raised to high-quality ride standards through careful selection of shocks and springs. This will help offset the unsprung weight generated by the rear of the vehicle bouncing around when a bump is encountered.
While the beam axle is capable of producing very good straight-line speed and handling, it falls far short of an independent axle in cornering and bump hits. When an independent axle encounters a bump, the tire moves up and over the bump as the spring absorbs the shock, and the damper gently places the tire back on the road. When a beam shaft encounters the same bump, the entire shaft leans to one side when one side of the shaft is sent up and over the bump. This causes both tires to ride on the sidewall, limiting traction and causing an unstable handling characteristic.
Some early vehicle designs used a beam axle at the front of the vehicle. This is partly due to the fact that the manufacturers of the vehicle are mostly old wagon makers and the strong front axle used on horse-drawn wagons. The axle design continues to be used on semi trucks as well as other large trucks due to axle strength. Other versions of the straight axle have experimented with softer, spring-type steel in the housing to function as a type of stabilizer bar and axle housing in one package.
Protect your devices with Threat Protection by NordVPN
