The rear axles work as drive axles by providing the motility power to the tires of the tractor and trailer. You can find it by checking the power flow, propelling force, and connection with the driveshaft.
Which Axle is the Drive Axle on a Semi Truck? The rear tandem axle is the drive axle on a semi truck that connects with the engines through the driveshaft and differential, links with the gearbox, propels the unit in the forward direction, and can handle 4300 pounds to 4400 pounds; the tandem axle can withstand 35000 pounds to 36000 pounds and last for about 110000 to 120000 miles. 6×4 and 6×2 are famous configurations that stabilize the semi-truck at high speeds, provide constant power to the wheels, protect frame damages, reduce tire flatting, withstand braking force, provide traction, absorb shocks, and move the wheels.
It improves traction, stabilizes tires on rough surfaces, and facilitates smooth riding. With a locked power divider, both rear rotational rods operate the unit.
- 1 Which is a drive axle on a semi truck?
- 2 How many drive axles does a semi-truck have?
- 3 What are the benefits of a drive axle on a semi-truck?
- 4 How much weight can the drive axle of the semi truck handle?
- 5 How long does the drive axle last on a semi truck?
- 6 What is the difference between a steer axle and a drive axle?
Which is a drive axle on a semi truck?
It is a specific component that provides the motive energy to the tires. It connects with the engine of the truck through the differential and driveshaft.
It directly links with the gearbox, provides power for the gear shift, and propels the vehicle in forwarding and backward directions.
It can convert the electric energy of the engine into mechanical power, transmit it to the tires and rotate them.
On heavy transportation units, the equipment is present on the rear side. For example, the rear one is the power rod of a semi truck, works as the power component, and moves the tires at different speeds.
The tractor and trailer cannot move in a particular direction due to the absence of this equipment. With the locked differential, all the rotational rods can move the trailers with maximum traction.
The manufacturing companies are offering a 6×4 configuration for heavy-duty trucks. The system has a rear tandem which comprises the rotational components.
With such configurations, both rods on the backside can propel the unit in the front and back direction.
Nowadays, 6×2 drivetrains are popular due to optimized performance and improved work efficiency to manage the fleet and regular operations.
With a 6×4 drivetrain, the front unit has three tires on either side, and the engine provides power to the four positions on the rear side of the variant.
How many drive axles does a semi-truck have?
Primarily, the semi-trucks have one drive axle on the back side of the variant. But, the heavy load carriers with separate cargo have two rear drive components.
With rough road riding, the dual rods make the riding smoother and secure the frame from damage. These units have five working units with an attached trailer.
Otherwise, it has only three rods with one or two drive axles. The equipment on the rear end generates and provides the motility power to the wheels by connecting to the camshaft and engine.
The trailer does not comprise a separate engine for individual performance.
The trailer does not have a drive rod due to the absence of an electric motor. It takes the mobility power from the engine of the front tractor.
What are the benefits of a drive axle on a semi-truck?
It benefits the frame of a semi truck by providing maximum control over the tires. It prevents swaying and idling of the cargo section and protects from accidents.
Stability at higher speeds
It provides stability to the wheels in high-speed conditions. In addition, it prevents the sudden rolling of the unit from the sloppy surfaces.
It has constant velocity joints that provide balance to the tractor-trailer frame. They keep the tires stable and allow them to rotate freely.
At high speeds, it can turn the wheels without any friction. It is reliable equipment that makes the stop easier.
It prevents the idling of the vehicle at higher accelerations. It controls the cargo and prevents swaying.
It stabilizes all 18 wheels in one alignment. As a result, the unit can run on rough and uneven roads without damage.
Safety of the frame
Tractor trailers have massive cargos which can transport heavyweight objects. The drive rod has a specific housing to protect the equipment.
The housing enhances the performance of the drive rod. The system works efficiently for long-distance shipment activities.
The equipment keeps the frame secure from sudden swaying. It prevents the striking of the unit body into the surrounding vehicles and other road obstacles.
Constant power for mobility
The driving rod connects with the driveshaft and provides constant power to the rational components. It can rotate the wheels at different speeds with minimum internal wearing.
It delivers mobility power to the driving wheels of a tractor-trailer. It has dual shafts which connect with the differential of the system. The drive rods rotate with the tires of a semi-truck.
It maintains the level of power flow and keeps the unit mobile. It provides the aerodynamic effect, resists the wind, and pulls the trailer forward.
It provides moving power to the cargo section that lacks an engine. With this equipment, the tractor and trailer move at a similar speed.
Defense mechanism against flat tires
These units have 18 wheels on the tractor and cargo section. They rotate and move in a similar direction due to the alignment of the different driveshaft. The rear wheels bear the weight of heavy materials.
They can damage due to pressurized conditions and internal damages. But, the rear-drive rod protects the flatting of tires and keeps them intact for a long time.
Moreover, its housing enables a stable operation of the 18-wheeler to a long-distance destination.
Better traction and control
The equipment handles the front and rear parts of the frame. It provides better traction during off-road riding.
It provides control of the steering wheel and tires on an uneven road surface.
The road grip increases due to the presence of a control rod. As a result, the tires can cover thousands of miles without damaging their internal composition.
The driver can drive, turn and stop the semi truck without facing challenging conditions. Instead, it fights against the challenges that affect the traction of tires.
It automatically adjusts the pressure of wheels and overcomes internal damage.
With controlled conditions, the equipment removes the minor faults, readjusts them internally, and stabilizes the system.
The limited slip provides more torque and improves the road traction of all driving wheels.
Withstand the braking force
The equipment can bear the weight of the tractor and trailer due to its built-in specifications. It withstands the weight of passengers and cargo with significant damage.
The component fights against the forces of the braking system. It can tolerate the effect of driving on different types of roads.
It improves the control over the steering wheel. The driver can stop the tractor-trailer with a high-performance brake system while the semi-truck moves at high speed.
The weight of cargo and passenger compartment distributes on the rear rotational rod of a semi-truck. It can handle pressurized conditions with flexible shafts and effective locking differentials.
Absorption of road shocks
The semi-trailers facilitate the transportation of goods, heavy items, and hazardous material in the different states. The skilled drivers run these tractor trailers on rough roads at a constant speed.
They have specific shock absorbers, but the rotational rod absorbs the shocks of road bumps. It prevents the differential, crankshaft, and camshaft from sudden internal damages.
The shocks cannot run inside the equipment because the rear axle blocks the passage.
Stable rotation of driving wheels
The driving wheels can move the tractor-trailer forward at different speed levels. The drive axle provides rotational energy to the drive wheels.
It turns them in one direction to prevent a sudden accident. The equipment stabilizes the wheels on the tractor and rear trailer by their alignment.
How much weight can the drive axle of the semi truck handle?
It has multiple rotational wheels that can handle the cargo and passenger weights. According to Federal laws, an individual tire can handle around 4300 pounds to 4400 pounds.
The wheels contact the road surface, absorb the shocks, and propel the tractor forward.
According to vehicle weight limitations, the tandem axle group can handle about 35000 pounds to 36000 pounds. However, the weight handling capacity varies in different states of the USA.
You can identify the weight handling capacity of the driving rod on your tractor trailer by multiplying the distance with the center of gravity.
Then, add the moments and divide them by the wheelbase. Get the weight distribution on the rear rod and subtract the value from the total gross vehicle weight.
Check the vehicle identification number (VIN) or a pasted sticker to assess the weight limits. Open the glove boxes on the driver’s side and contact the manufacturer for detailed information.
How long does the drive axle last on a semi truck?
It has an average lifespan of about 110000 miles to 120000 miles on tractor trailers. Mileage, excessive usage, off-road riding, and heavy loads affect their shelf life.
With time, they damage due to wearing, corrosion, and internal malfunctioning. The equipment continuously rotates and flexes to fight against the round road surfaces.
As a result, they break and require immediate repairing conditions. Troubleshoot the malfunctioning components after about 21000 miles to 22000 miles.
The repairing, maintenance, and service can prolong their life. Unfitted shocks cannot support the driving components. Repair the broken shocks to prevent pressurized conditions.
What is the difference between a steer axle and a drive axle?
The steer is different from the drive axle because it is usually present on the front side of the tractor-trailer.
They have unique designs to provide versatile performance in the front position. The steering unit improves the handling of the tractor with the cargo compartment.
It smoothers the riding, stabilizes the wheels, provides more road grip, and repels road water splashes from the tires.
It secures the frame in the free-rolling conditions, protects the layout on wet and slippery roads, and prevents sudden damage to the tractor’s body.
The drive rod is on the rear side, rotates the front and rear wheels together, and provides maximum road traction.
It withstands the weight distribution, supports the transportation of heavy loads, and keeps the passengers safe.