What is a Drive Shaft? | How does a Drive Shaft work? (2024)

Adrive shaft is one of the most important parts of your car. It helps to transfertorque from the transmission to the differential. The driveshaft is also known as a propeller shaft or prop shaft. This article explains the drive shaft working, parts, types, and function.

What is a Drive Shaft?

Adrive shaft is a part of the drive train in a vehicle that transfers torque from the transmission to the differential, and then the differential delivers this torque to the front wheels to run the car. The drive shaft is also known as a Cardan shaft, propeller shaft, or prop shaft.

The drive shaft serves as a crucial component for transmitting torque across different parts positioned at a distance from each other. This is necessary because various vehicle parts are located in different areas.

In the case of a front-engine rear-wheel drive vehicle, a lengthy drive shaft is employed to connect the rear axle with the transmission, as these components are positioned on opposite sides of the vehicle.

Driveshafts fulfill diverse roles in various cars, exhibiting significant variations in cars with specific setups such as front-engine rear-wheel drive, four-wheel drive, and front-wheel drive vehicles. Drive shafts are also used in marine vessels, locomotives, and motorcycles.

These shafts have a different number of prismatic joints, leaf joints, universal joints, or jaw couplings to enable change in distance and alignment between drive and driving parts.

Working of Drive Shaft

The main function of the drive or prop shaft is to transmit the torque of the engine from the differential or gearbox to the vehicle wheels. In addition, any changes in angle or length caused by manipulation or deflection must be compensated for in order to ensure excellent synchronization between the shaft joints.

The drive shaft with a front-wheel drive has a connecting shaft, an inner constant velocity joint, and an outer fixed joint. It also has some other parts like torsional dampers and anti-lock system rings.

The vehicle has flexible bearings or mountings, which uses to connect the transmission unit and engine. However, the suspension spring uses to connect the wheels, differential, and rear axle.

Look at the above arrangement; the transmission input shaft and the output shaft of the rear axle casing are in several planes. This arrangement helps the drive shaft to connect the input and output shafts at an inclined angle.

When the rear wheels hit uneven surfaces, the rear axles move downward and upward, expanding and compressing in the suspension spring. This changes the angle between the propeller shaft and the transmission output shaft.

Due to this process, the length of the prop shaft varies. This change appears because the drive shaft and rear axle rotate in an arc along with a point of their rotational axis.

Parts of the Drive Shaft

The driveshaft has the following major parts:

1. Flanges
2. Slip yoke and Tube yoke
3. End yoke
4. Midship shaft
5. Universal joint
6. Centre bearing
7. Tube

1) Tube

The rear-drive vehicles and front-engine vehicles also have tubes. It is utilized to maintain the position or placement of the rear end while braking or accelerating the vehicle.

Read Also: Different Types of Engines

2) Flanges

The flange is employed to link the drive shaft with the differential, transfer case, and transmission. They are also used to link the propeller shafts with the hydraulic pumps, power take-offs, and many other components of the vehicle.

3) Center Bearing

The center bearing is utilized to link the two parts of the propeller shaft. In this way, the center bearing ensures the exact position of the drive shaft parts and decreases the harmonic vibration during the motion of the car.

4) Universal Joint

The universal joint is one of the most important parts of the propeller shaft. The universal joint is also known as a U-joint. It connects the revolving shafts of the vehicle.

At present, driveshafts with universal joints can be most commonly seen in four-wheel drive and rear-wheel drive vehicles.

5) End Yoke

The end yoke uses to ensure the durability and accuracy of the prop shaft.

The main purpose of the end yoke is to decrease the vibration and noise during vehicle acceleration. In this way, it ensures comfortable driving.

6) Midship Shaft

It is a major component of the drive shaft and coupling shaft linked with the housing on the center bearings.

7) Tube Yoke and Slip Yoke

The slip yoke directly connects with the drive shaft via a universal joint. This yoke slides inward and outward of the transfer case to deliver the power. A tube yoke also requires to successfully rotate the driveshaft and U-joint.

Read Also: Working of Planetary Gearbox

8) Tubular Shaft

This shaft uses to correct the distance factor between the rear axle and the gearbox. The driveshaft may have more than one tubular shaft according to the drive shaft type and vehicle model.

The length of this shaft varies according to the shaft distance from the gearbox. A short tubular shaft is installed for front-wheel drive, and a long tubular shaft is installed for rear-wheel drive.

The tubular cross-section delivers excellent flexibility and strength than the filled cross-section. These shafts have lightweight.

Types of Drive Shafts

The drive shaft has the following major types:

1. Single Piece shaft
2. Two or Three Piece shaft
3. Front Wheel Drive

1) Single Piece Shaft

These types of drive shafts are used in four-wheel-drive vehicles and many other vehicles that have a small distance between the axle and the engine. There is applied friction welding to improve the durability, quality, and strength of the single-piece drive shaft.

This type of propeller shaft is made of lightweight material like aluminum which needs a larger diameter to attain similar excellent strength as a steel shaft. The following are some problems with this approach:

1. It can be damaged more easily.
2. Large clearance requires for the shaft accommodation and its harmonics.
3. The single-piece shaft has a high manufacturing cost.

2) Two or Three-Piece Propeller Shaft

These shafts are used to stop the driveshaft damage due to bending at high speed. Two or three-piece shaft uses for four-wheel-drive vehicles and vehicles with a large distance between the axle and engine. You can reduce the speed by dividing the driveshaft into two or three parts.

When the shaft doesn’t bend, the floor or the transmission tunnel above the shaft lowers to create more space for passengers or luggage.

3) Front-wheel Drive (FWD)

First of all, you need to know that the front-wheel vehicle doesn’t use a driveshaft. In front-wheel drive vehicles, the front wheel provides the power to drive the vehicle.

In contrast to the long drive shafts in rear-wheel vehicles, all parts of the drive train of the front-wheel-drive vehicle are located in the vehicle’s front area. The wheel drive shaft uses constant velocity (CV) joints instead of universal joints.

In the front-wheel vehicle, the axle and the transmission are joined in one unit, known as a transaxle.

Symptoms of Bad Drive Shaft

The proper working of the drive shaft is too much important for the proper operation of the car or any other vehicle. In case of driveshaft failure, you must replace it immediately.

Following are some most common signs of a bad or failing drive shaft. If you observe the below-given symptoms, you need to replace your propeller or drive shaft immediately.

1. Vibration
2. Knocking noise
3. Squeaking noise
4. U-joint motion
5. Turning issues

Read More: Symptoms of a Bad Power Steering System

Advantages and Disadvantages of Driveshaft

The drive or propeller shaft has the following advantages and disadvantages:

Advantages of Drive Shaft

• There are no or very low power losses.
• These shafts have high durability.
• The drive shaft doesn’t have complex construction.
• It generates very low noise at high torque.
• They need less maintenance compared to the chain system.
• The Drive system doesn’t jam easily.

Disadvantages of Drive Shaft

• This shaft has high weight than a chain system.
• The chain system has more efficiency than a propeller shaft.
• The prop shaft has much damage when the speed is very high.
• These have oil leaking issues at the spline.
• Hollow driveshaft has a high cost.
• These are not the best shafts for counter-bending forces.

Applications of Driveshafts

• Automotive Industry: In the automotive industry, drive shafts are most commonly used in four-wheel drive vehicles and rear-wheel drive vehicles. These shafts are used to transmit power from the engine to the differential which further turns the vehicle’s rear wheels.
• Aerospace Industry: They are also used in helicopters and aircraft, especially in transmission systems.
• Marine Industry: Driveshafts are used in ships and boats to deliver power from the engine to the propeller.
• Industrial Machinery: They are used in different industrial machinery, such as agricultural machinery, conveyors, and manufacturing equipment.
• Power Generation: Drive shafts are employed in power plants to make a connection between generators and turbines.
• Construction Machinery: They are used in different construction machinery, including cranes, loaders, and excavators. These shafts enable the movement and operation of these heavy-duty machines.
• Motorcycles and Bicycles: These shafts are employed in a few bicycles and motorcycles as an alternative to belt drives.

Drive Shaft Repair Cost

The repair and replacement cost of the drive shaft varies according to the area where you live and the part which you want to be repaired. The average replacement cost of a drive shaft varies from $490 to $1100.

If you don’t replace it yourself and hire labor, the labor can also charge up to $250. Even for a simple repair, you would need to pay from $1400 to $1800 for the repair process.

If you want to repair only half a section of your shaft, you would need to pay from $340 to $860 for this process, with the labor cost from $140 to $260.

In the case of 4-wheel drives, the repairing price will rise. For this type of repair, you will need to pay from $650 to $1850 according to your residential area.

FAQ Section

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