Differentials and Axles Information


A differential is a mechanical linkage converting the motion of a rotating nature from one source to two axles. It permits faster rotation of the outer drive wheel compared to the inner unit when a vehicle is turning. Differential components include the drive shaft and two wheels.

 Axle from Dana Holding Corporation

An axle is a structure acting as a central shaft of a revolving part. Typical vehicles feature two types of axles. Most constructions are secured to the surroundings or linked to the wheels. If the element is fixed, the system comes with bearings or bushings positioned at the mounting points supporting the axle. Alternative versions install these components in the wheel's center hole.


Standard automobile units employ a driveshaft stretching from the motor to the gearing arrangements. Drive wheels have fragmented axles facilitating consistent speed and direction of movement.


An axle shaft with full floating functionality has the ability to transfer torque from the differential to the wheels. However, it is incapable of supporting the weight of the construction. Such shafts are suitable for sustaining the strain induced by torque. This option is beneficial as the breaking of an axle shaft does not cause the wheel to dislodge and detach from the running vehicle.


They are common in light, medium, and heavy trucks. Agricultural machinery and other similar fields engage them as well. Semi-floating models possess the ability to endure a unit's weight. Designs such as these are available in lighter trucks, SUVs, and old passenger cars with rear-wheel drive.




The axles support numerous configurations, including:


Drive: It is propelled by an engine or a prime mover. The product is fragmented, and it comprises a differential and universal joints. Each part of the device links to the wheel by a constant velocity joint, making the assembly free to move and permitting pivoting movement while turning. The engines of rear-wheel cars make the driveshaft turn, resulting in the transfer of rotational force to the drive axle at the vehicle's back. Simple motorized units such as go-karts engage an analogous axle split into two.


Transaxle: A combination of a gearbox, differential, and front axle present in contemporary front-wheel drive cars. The solution is present in almost every automobile with engines positioned next to the driven wheels.


Dead: The model is a free rotating instrument disconnected from the drivetrain common in front-wheel drive cars. The category supports substantial loads. Therefore, automotive units including trucks, trailers, farm equipment, and heavy construction machines incorporate this device. The wheels on the structure make contact with the ground only when there is a significant amount of load, leading to less friction. Instruments situated right in front of a drive axle are known as pusher axles, while configurations found behind are tag versions. The latter sometimes includes the ability to allow steering.


Lift: As the name suggests, this classification offers a mechanical raising and lowering capability. Also called the airlift or drop, the mechanism is present in dump trucks and trailers. The lowering function of the component enables weight distribution of the cargo over other wheels and aids in enhancing weight-bearing capacity. The element is raised allowing easy turning of the vehicle and providing extra traction to the remaining gearing arrangements, also reducing depreciation of the tires. In select systems, computers control the movement of these instruments.


Beam: The design comprises a set of wheels joined with a single beam or shaft. The devices are also referred to as rigid or solid and are connected with the back or front wheels. Many modern vehicles install front and rear independent suspensions in place of the beam solutions.





Several models of differentials are available today, including:Axle from Comer Industrie, Inc.


Epicyclic: The structure assists in the asymmetrical division of torque in the front and back axles by engaging epicyclic gearing. Epicyclic gear arrangements are comparatively smaller.


Spur-gear: Vehicles manufactured in old times deployed this alternative. At present, it serves non-automotive functionalities. The product comes with two separated gears of an equivalent size. A rotating carrier is present at the center of the component in parallel alignment to the axis of the two shafts. It revolves via torque from a prime mover.




Differentials and axles are present in almost any wheeled vehicle or machinery. As their function complements movement, they are indispensable in the automotive industry.


Image credits:

Dana Holding Corporation | Comer Industries, Inc.