What is Drive Shaft? Definition, Types & How Does it Work?

In this article, we are going to learn all about drive shaft, its definition, meaning, different types of drive shafts, how does it work and many more. In order for a vehicle to move smoothly and fluidly, it must have many moving parts that get them to work. Vehicles of all sizes have a variety of features that are important to understand. The understanding of how a drive shaft works is a major necessity. The breakdown of this part could have significant consequences for other crucial components of the vehicle.

What is Drive Shaft? Definition & Meaning

The Drive Shaft, also called a propeller shaft or a prop shaft and sometimes also known as the drivetrain system, is a component of the drive train in a vehicle that transmits torque from the transmission to the differential, which then transmits it to the wheels. The Drive Shaft is an extremely important part for most types of cars and other vehicles.

It is the drive train system that helps you drive your vehicle forward, whether you are driving a truck, Sports Utility Vehicles , or compact cars. When you shift into driving, the drive shaft transfers torque and engine rotation into vehicle motion.

• In vehicles, the drive shaft primarily transfers torque between the components due to their location. Due to the fact that the rear axle and transmission are on opposite sides of a front-engine rear-wheel drive car, a long drive shaft must connect the rear axle to the transmission. To allow deviations in alignment and distance between drivers and driven components, drive shafts are often equipped with universal joints, jaw couplings, rag joints, or splined joints.
• The Drive Shaft is used in various ways in different types of vehicles. The number of rear-wheel-drive cars varies greatly depending on whether they are front-wheel drive, four-wheel drive, or the previously mentioned front-engine rear-wheel drive. In addition to motorcycles, locomotives, and marine vessels, drive shafts are used by other vehicles as well. A typical rear-wheel drive car’s drive shaft configuration is shown below (some cars have the transmission behind the rear axle).
• In vehicles, drive shafts transfer power from engines and PTOs to accessories like air compressors. The drive shaft bridges the gap between the engine PTO and the accessory that can be mounted elsewhere on the vehicle when it is not possible to accommodate it beside the engine.

History of Drive Shafts

It was during the mid-19th century that the term drive shaft first appeared. The term is used in Stover’s 1861 patent reissue of a planing and matching machine to describe the belt-driven shaft that drives the machine. The term was also used in a patent reissued for a horse-drawn mowing machine by Watkins and Bryson in the year 1861. In this term, shafts are used here in order to transmit power from the wheels of the machine to the gear train that operates the cutting mechanism.

As the term grew closer to modern usage in the 1890s, it became more widely used. For instance, Battles referred to the drive shaft in his Climax locomotive as the shaft between the transmission and the driving trucks in 1891. A universal joint is found in Bukey’s Horse-Power in 1899, which transmits power between the wheel and driven machinery. Clark referred to the gear-driven shaft in his Marine Velocipede as the propeller shaft via a universal joint in the same year. First gasoline-powered cars were manufactured by Autocar, a pioneering automobile manufacturer. Today this vehicle is in the Smithsonian Institution’s collection, it was built in 1901.

How Does Drive Shaft Work?

Let’s try to understand how does a drive shaft work or its basic working philosophy:

• A prop shaft or drive shaft transmits torque from the engine to the vehicle wheels through its differential or gearbox. For improved synchronization between shaft joints, an adjustment must also be made to any angles or lengths that result from manipulations or deflections. 
• It is impossible to drive without the transfer of torque between the different components. As a result of the drive shaft, two parts can move independently without breaking drive train components.
• The drive shaft of a front-wheel drive has a connecting shaft, a fixed joint at the centre, and a constant velocity joint at the front. Additionally, it includes anti-lock system rings and torsion dampers.
• Unlike rear-wheel-drive vehicles, front-wheel drive vehicles do not have drive shafts. A transaxle is the combination of transmission and axle. Unlike rear-wheel drive vehicles, however, four-wheel drive vehicles have separate transmissions and axles. Drive shafts transmit the steering motion of transmissions to axles.
• To connect the transmission unit and engine, the vehicle uses flexible bearings or mountings. Wheels, differentials, and rear axles are all connected by the suspension spring.
• Uneven surfaces cause suspension springs to expand and compress. Propeller shaft and transmission output shaft angle change as a result.
• It is because of this process that the prop shaft varies in length. There appears to be a change because the drive shaft and rear axle are rotating in an arc along with their rotational axis

Parts of Drive Shaft

Every Drive Shaft generally has the following parts, these parts are:

• Tube Yoke and Slip Yoke
• Tube
• Centre bearing
• Flanges
• End Yoke
• Universal joint
• Midshift Shaft
• Tubular Shaft

Tube Yoke and Slip Yoke 

By means of a universal joint, the slip yoke is directly connected to the drive shaft. Power is delivered by this yoke sliding inward and outward within the transfer case. It is also necessary for the driveshaft and the U-joint to be rotated successfully if a tube yoke is used.

Tube

Vehicles with rear engines and front engines have tubes as well. During braking or acceleration, it is used to keep the rear end’s position or placement

Center Bearing

The drive shaft is linked together by the center bearing. By doing so, the center bearing ensures that the drive shaft parts are precisely positioned and reduces harmonic vibrations.

Flanges

Propeller shafts are connected to differentials, transmissions, and transfer cases by the propeller flange. In addition to being used to link propeller shafts with hydraulic pumps, power take-offs, and many other parts of the vehicle, these also connect hydraulic pumps to propeller shafts.

End Yoke

Using the end yoke, the prop shaft is maintained in a durable and accurate way. During vehicle acceleration, the end yoke is intended to reduce vibrations and noises. As a result, the driving experience is made more comfortable.

Universal Joint or U-joint

Among the most important parts of the propeller shaft is the universal joint. Universal joints also be called U-joints. An integral part of the vehicle that connects its revolving shafts.

Most vehicles with four-wheel drive or rear-wheel drive are equipped with drive shafts with universal joints.

Midshift Shaft

Linked to the housing on the center bearings, it is a major component of the drive shaft and coupling shaft.

Tubular Shaft

The purpose of this shaft is to correct the distance factor between the rear axle and the gearbox. It is possible for a drive shaft to have more than one tubular shaft depending on the type of drive shaft and the type of vehicle.

Depending on the distance between the shaft and the gearbox, this shaft varies in length. For front-wheel drive, a short tubular shaft is used, and for rear-wheel drive, a long tubular shaft is used. In comparison to filled cross-sections, tubular cross-sections are stronger and more flexible than filled cross-sections. Lightweight shafts are available with these shafts.

Different Types of Drive Shafts

There are different varieties of drive shafts which perform different types of functions . The types of Drive Shafts are

• Front Wheel Drive or FWD
• Two or Three Piece shaft
• Single Piece shaft

Front Wheel Drive (FWD)

As a first step, you need to know that front-wheel vehicles do not use drive shafts. Vehicles with front-wheel drive are powered by their front wheels. Front-wheel-drive vehicles with short drive shafts have all parts of their drive train placed in the front of the vehicle, as opposed to rear-wheel vehicles with long drive shafts. In lieu of universal joints, wheel drive shafts are fitted with constant velocity (CV) joints. The transaxle, also called the axle-transmission unit, is the unit that connects the axle to the transmission on a front-wheel vehicle.

Two or Three Piece Drive Shaft

In order to prevent drive shaft damage due to bending at high speeds, these shafts are used. Four-wheel-drive and vehicles with a long distance between axles and engines use two- or three-piece shafts. The drive shaft can be divided into two or three pieces to reduce the speed. In the absence of bending of the shaft, the floor or transmission tunnel above the shaft lowers to create more space for passengers and luggage.

Single Piece Shaft

A four-wheel-drive vehicle and many other vehicles with a small distance between the axle and the engine make use of this kind of drive shaft. An applied friction welding process improves the strength, durability, and quality of the single-piece drive shaft. Lightweight aluminium propeller shafts need a larger diameter to achieve similar excellent strength to steel shafts. This might some of the following problems such as

1. It becomes more prone to damage
2. It is necessary to provide a large clearance for the shaft accommodation and its harmonics.
3. There is a high manufacturing cost associated with single-piece shafts.

Drive Shaft Problems Signs and Symptoms

It is difficult to control your vehicle when your drive shaft is damaged or failing. Check out the following signs and symptoms to look for. Mechanics will be able to diagnose and fix your drive shaft problems if your car exhibits any of these symptoms.

Due to their high speed and torque values, drive shafts are very precisely balanced and weighted components. The drivability of a vehicle can be affected when the drive shaft is malfunctioning. An issue with the drive shaft usually produces four symptoms that alert the driver to the problem.  The propeller or drive shaft needs to be replaced immediately if you observe the symptoms listed below.

1. Intensive vibrations from beneath the vehicle
2. Noises that are abnormal
3. Problems while turning
4.  Shuddering During Acceleration
5. Drive shaft cover soiled or torn

Intensive vibrations from beneath the vehicle

Experiencing intense shaking and vibrations from under a vehicle is a common symptom of a failing drive shaft.  Drive shaft vibration is caused by worn out universal joints (U-joints) or bushings. For drive shafts not to vibrate during installation, they are finely balanced before the installation. There is a problem if there is any kind of vibration. When a drive shaft vibrates excessively, passengers will not only feel vibrations, but other drivetrain components will also experience accelerated wear.

Noises that are abnormal

As a result of a problem, the drive shaft may also make abnormal noises. Bearings or bushings supporting the drive shaft or U-joints that wear out or fail can cause the drive shaft to be unable to rotate properly. The vehicle may rattle, clunk, scrape, or even squeak under this condition.

Squeaking at low speeds may also be caused by lubricated U-joints. A CV joint that clicks or knocks can be regarded as a faulty one. When the vehicle makes such noises, it should be serviced immediately. There could be other types of different types of sounds such as

Squeaking Sounds: You can hear squeaking sounds from your drive shaft because of a couple of issues. In most cases, they do not indicate that the drive shaft has failed, but they do indicate that the bearings or U-joints needs to be lubricated.

Clunking Sounds: A loud clunk or knock will be heard from underneath the vehicle. The sound usually indicates a badly worn U-joint needs replacing.

Rattling and Scraping sounds: Rattling and scraping noises may also be heard. These sounds indicate that some parts of the drive shaft need lubrication or are worn out. It is important to bring your car in for inspection if you hear any noise in it.

Problems while turning

Besides converting torque into movement, the drive shaft also affects how your vehicle turns. You may be experiencing trouble turning when taking a turn because your vehicle’s drive shaft is failing.

Having a damaged drive shaft limits your control over the car, as well as the wheels’ ability to turn properly. It is a serious safety problem that needs to be addressed immediately.

Shuddering while Acceleration

It is much more noticeable to notice the shuddering issue than the vibrations we discussed. When the drive train is defective, you might notice a significant increase in shuddering as you accelerate from a stopped position or increase speed.

There are times when a loose U-joint or a worn-out center bearing will result in this problem. Some of the sounds we discussed previously could also accompany it.

Drive shaft cover soiled or torn

You will see this rubber-like material on your drive shafts called a drive shaft cover / constant velocity boot. Its main purpose is to keep contaminants from entering the constant velocity joint and to keep lubricating grease in place.

When you know where to look, you can detect a torn cover. It only takes putting on some dirty clothes, crawling underneath the car, and finding the drive shaft. Your drive shaft cover will be visible with a crack or puncture. You will usually see grease splashes around your car’s tyre when this happens.

You should replace a spoiled cover as soon as possible. It is important to remember that your drive shaft cover is the only line of defense. Moisture and dirt are kept out while lubricating grease is kept in.

It is always important to keep drive shafts and other moving parts lubricated with grease. The constant velocity joint reduces metal-to-metal contact by cushioning it. As an airbag, you can think of them. Instead of banging straight against the metal wall, ball bearings inside your drive shaft should hit a soft material. Lubricating grease prevents metals from colliding with one another and wears out more quickly.

To make matters worse, a torn constant velocity boot allows dirt and moisture to enter your drive shaft. As moisture comes into contact with metal, it forms rust and eats away at it. Your drive shaft’s structural integrity is destroyed as a result. Conversely, dirt and sand will grind against your drive shaft’s metal part and cause it to wear out much more rapidly than it should. Constant velocity joints shouldn’t have sandpaper inside them, it is a big no.

A drive shaft that has only broken its cover can simply be greased and the cover replaced if it remains in pristine condition. There is no need to replace the entire unit as it is a simple repair. Maintaining it this way is the most important and cost-effective method.

Drive shaft covers that are spoiled or torn often go unnoticed. Symptoms other than a punctured drive shaft cover do not indicate a torn drive shaft cover. The drive shaft will deteriorate exponentially if the cover is not changed, and you will start to hear noises and vibrations.

Having said that, routine inspections can be done once every week or so if you are determined enough. If your cover is torn, call a mechanic immediately to have it repaired.

How to Choose the Correct Drive Shaft for Your Vehicles?

In the event that your drive shaft breaks and renders your vehicle undriveable, it is important to figure out which shaft needs to be replaced. Vehicles have different shaft configurations, each with its own unique characteristics. Based on whether your vehicle is front-wheel drive, four-wheel drive, front-engine drive, or rear-wheel drive, you will need to find the correct part.

Cost of Repairing or Replacing a Drive Shaft?

In the event of failure, you can get your drive shaft repaired or buy a new or get a custom drive shaft according to your requirements. When drive shaft problems are addressed immediately, no harm is done to the components surrounding the drive shaft.

Usually, all of the above parts are replaced along with the drive shaft itself when a drive shaft needs to be replaced. It depends on the type of car you drive when it comes to the cost of a drive shaft. Driver shafts for powerful cars and large SUVs tend to be more expensive than those in regular sedans or coupes.

There are several factors that determine the cost of repairing and replacing a drive shaft, including the area where you live and the part you would like to replace.

Drive shaft replacement costs range from $490 to $1100 on average. In the case of a front-wheel-drive vehicle, replacing just the half-shaft will cost $470 to $940.

There will be a difference in price if you are repairing only a half portion or half of the shaft. Depending on where you live, this can cost anywhere from $350-$850. As with all repairs, parts cost about average. In addition, labor costs ranging from $150-$250 based on the service center, state, and taxes.

There will be an increase in the cost of repairing 4-wheel drives. According to your residential area, you will need to pay $650 to $1850 for this type of repairing.

How Can You Save Money on a Drive Shaft Repair?

Make sure you do your research. If you are attempting to repair a drive shaft on your own, you may find it tempting. But you should keep in mind that it will cost you more money in the long run if you do not have the right tools to repair your drive shaft.

You can take these following steps in order to save a bit of your money.

1. You should first compare the prices amongst all your local shops that repairs driveshaft
2. Next as for a a cost estimations including the prices they charge for all the tools, parts and charges for labour. If you decide to buy the parts yourself, you can ask what parts will need to be purchased and you might get a cheaper deal.
3. If you bundle the repair with another maintenance item, the repair shop might offer a discount.

How Can You Fix a Damaged Drive Shaft in an Emergency?

Firstly, you should be warned that the drive shaft is a crucial part of your vehicle and can cause different types of risky and serious problems in case the repairing or replacement of a bad drive shaft goes wrong. But if you are in a situation where you can not hire a mechanic or you want to save some extra money then you can try to fix the drive shaft by yourself.

In order to remove the driveshaft from a car or truck, you must first remove the front axle. Make sure the front yoke is in good condition. By doing this, you will be able to determine if the rear seal in the transmission needs to be replaced. The bearing cup must first be removed by driving the driveshaft towards one side. After that, you can turn it over and repeat the process if you can. It is imperative to ensure that you have some way to support the unit. If you have a large cinder block, that will work. In order to install bearing cups into the driveshaft, remove them from the new joint. Attempting to complete the process should be done gradually. Some other ways and steps to fix a broken drive shaft is discussed below:

Hubs need to be cracked: The split pin should be removed from the hub nut while the car is loaded, and then the hub nut should be cracked off to allow it to fall off. However, do not remove it completely. There will be a big nut to remove, approximately 30mm in diameter, so you will need the proper socket. Besides, they are capable of being torqued to over 250Nm, so it will take a lot of effort to turn them.

Jack up the car: Put the car on axle stands since you would not be doing anything with it on the ground. Stands are not just for safety reasons here; you also need the wheels to be in the air and ramps are not adequate.

Brakes and Wheels: Remove the wheels, put them under the car for safety, and then apply the brakes. However, the brake line would not need to be disconnected during the removal of the caliper. To avoid weight or tension on the brake hose, suspend the caliper with sturdy cable ties or metal wire.

Check the hubs: Now that the hub nut is freed, you can remove it completely. If possible, it’s better to remove the brake disc at this stage – you do not always have to, but it takes just 20 seconds to do so and makes it easier to access the brakes.

Check joints at the lower end: Disconnect the hub assembly and lower arm with a ball joint splitter after undoing the nut on the lower ball joint. The outermost end of the hub should now be free from the drive shaft. There may be times when the anti-roll bar needs to be removed.

Gearbox end: It is either easy to slide out the shaft, or a little gentle persuasion will be required due to the circlip holding it in.

After aligning the splines correctly, tap them with a rubber mallet to ensure they are installed correctly. The next step is to tighten the hub nuts to a torque that is specified by the manufacturer for which you can refer to the instruction manual.

Even though the Drive Shaft Repair process might seem challenging, you can accomplish it successfully. As you get used to it, it takes time to become accustomed to it. The effort, however, can be totally worth it at the end of the day. It is just a matter of checking it out, and you will be pleased with the experience. If you are looking for Drive Shaft Repair services, make sure to find the right company for you!

What are the Merits of a Drive Shaft?

Having a drive shaft in a vehicle has the following merits :

• Jams are less likely to occur on the drive system.
• In comparison to the chain system, they require less maintenance.
• In the event that clothing or part of the body catches between an unguarded chain and sprocket, the rider will not be contaminated with chain grease or injured by a “chain bite.”
• Improved consistency of performance. According to Dynamic Bicycles, a drive shaft bicycle can deliver 94% efficiency, while a chain-driven bicycle can achieve 75 to 97% efficiency.
• At high torque, it generates very little noise.
• There is no complex construction on the drive shaft.

What are the Demerits of a Drive Shaft?

• As compared to drive shafts, chain systems are more efficient.
• A chain-driven bicycle can also achieve many of the advantages claimed by proponents of drive shafts, such as the ability to cover the chain and sprockets.
• Although hub gears can be used, lightweight derailleur gears with a high number of ratios are not possible.
• There is a high cost associated with hollow drive shafts.
• It is not recommended to use these shafts for counter bending forces.
• There are oil leak issues at the splines on these.

Frequently Asked Questions (FAQs)