How Do Semi-Truck Differentials Work?

Semi-trucks are heavy vehicles that are used to haul and tow heavy objects from one place to another. The rotation of the wheels affects the stability and performance of these trucks. The differentials are the basic components that deliver rotational power to the wheels.

How Do Semi-Truck Differentials Work? Semi-truck differentials help the outside and inside wheels to rotate independently of each other while taking turns. Open-handed locking and limited slip are types of this equipment. The worn-out differentials produce a banging sound, and oil leaks from the axle seals. They can last for up to 150000 to 160000 miles.

The drivers of the semi-trucks should have proper knowledge about all the parts of the vehicle. They should also have all the skills to troubleshoot minor defects in the differentials and other components of the vehicle. It will prevent all the accidents and damage to the trailer and drivers.

What are the differentials in a semi-truck?

The wheels of a vehicle spin continuously to move it on the road. The speed and rotation of these wheels are controlled by many components present in the semi-trucks. Differentials are mechanical equipment that helps in controlling the speed of the wheels.

They play an essential role in stabilizing the vehicle when it is taking a turn. These components are gearboxes that deliver power from the engine to the wheels.

They allow both front and rear wheels to rotate at different speeds when taking turns. It helps in getting maximum traction on curvy roads and keeps the truck stable.

Otherwise, all wheels will spin faster without any regulation and cause damage to the truck and the driver.

These mechanical parts also have a role in the braking system of the semi-trailers. If one wheel is hard to brake, these differentials deliver power to this wheel. In this way, all four wheels will come to a stop at the same time.

Types of differentials in a semi-truck

Semi-truck differentials are of different types depending upon their function and use. Here is a brief description of all of them.

Open-handed differential

It is the most basic type of differential system in the semi-trucks. It distributes the torque equally on all wheels. It helps all the tires to spin at the same speed.

This type is suitable for smooth driving on even roads. When the traction is uneven on front and rear roads, it delivers power to the tire with less traction.

Locking differential

It can lock the axles together to deliver all the torque to the wheel with the highest traction. It is helpful in off-road conditions.

Limited slip differential

It is also called torque sensing. It delivers power to the wheel to enable it to rotate at different speeds. It can shift the power to the tire with high traction to maintain stability.

Torque vectoring differentials

It fine-tunes the amount of torque delivered to each wheel on the semi-trucks. It means each tire gets a specific amount of torque for rotation.

How does semi-truck differential work?

Differentials have four main features to provide independent rotation to all wheels. These features include the following.

  • Differential gear
  • Output shaft
  • Differential cage
  • Planetary gear

All these features work in different conditions to provide the right amount of power to wheels for rotation.

On a smooth road, the differential cage and the planetary ears work to rotate the wheels. Both of them will turn at different proportions to turn the vehicle.

When off-roading, the output shafts and planetary gears turn at different speeds. It is crucial to keep the outside wheels moving for a long distance.

In other words, this equipment provides resistance to inner wheels to make them rotate at a lesser speed.

It is essential to keep the balance between wheels when taking turns. In this way, it prevents the risk of collision and accidents with other automobiles.

Number of differentials in a semi-truck

The semi-trailers have two differentials on both front and rear axles. These mechanical components help to move the right and left wheels independently of each other.

They can be located on the front, center, and rear of the axle. They also improve the traction and towing capacity of the semi-truck.

It prevents the truck from skidding and provides a safe journey along a curvy road. Otherwise, it will be difficult because all the wheels will spin at the same speed.

How do I know if semi-truck differentials are worn out?

The differentials can get damaged due to mishandling of the trucks. Aging is another reason for this equipment going bad before time.

The road conditions and driving kills of the drivers can also significantly impact the performance and health of these parts. But like all other components, they also show signs of damage before going bad. Here is a brief description of all these symptoms.

Oil leakage from the semi-truck axle seal is the main symptom of a failing differential. If you are seeing brown liquid beneath the semi when it is parked, it could be due to worn-out differentials.

Noises from the vehicle are another sign of a damaged differential. The banging and rumbling sound from the truck’s parts is a sign of fault in them. Tire wear is another significant sign of fault in these essential parts.

You will also have difficulty handling the steering and controlling the trailer while taking turns. The drive shaft also gets out of balance due to faults in them.

It is preferred to check these signs to keep these parts functional. You should repair the seal and bearing of axles to keep them functional.

How long do the semi-truck differentials last?

The life expectancy of semi-truck differentials depends upon the driving conditions and service schedule of the vehicle. The type of oil and lubricant also impacts the lifespan of these parts.

They are made from heavy metals like steel or iron. They can withstand many hardships while the vehicle is moving on the road. On average, these parts can live up to the lifespan of the semi-truck if handled properly.

You should replace the lubrication oil every 50000 to 60000 miles to keep them working. With proper care and maintenance, differentials in this vehicle can last for up to 150000 to 170000 miles.

Repairing these parts is usually a cheaper option than replacing them. On average, the price of semi-trailer differentials varies from $250 to $400.

How to take care of differentials in the semi trucks?

Proper care and maintenance help to prolong the life of all the parts of any automobile. You can increase the life expectancy of these equipment by many years by following simple rules to take care of them.

Changing the lubrication fluid is the primary step in the maintenance of the equipment. Change the fluid every 50,000 miles. If you are driving on a rocky and rough road, change it every 30,000 miles.

The fluid helps prevent overheating in these parts. Remove the dirt and grease from all the components of the differentials. Choose high-quality lubrication fluid to lubricate them.

Check the bearings and shaft for any defects and repair them on time. Choose high-quality spare parts to replace the old ones.

Always get them serviced by a professional mechanic; do not do it yourself to avoid any trouble. Try to drive the semi-truck on smooth roads and avoid the puddles and sandy roads.

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