What are Car Differentials? Definition, Meaning, Types, Parts, Importance

What are Car Differentials? In this article, we will learn along with Definition, Meaning, Types, Parts, Problems, Importance, etc. If you’ve ever played with a toy automobile, you know that it can only go straight; it cannot turn. This is due to the lack of a difference. But regardless of whether it has a front, rear, four, or all-wheel drive, your car spins or bends unusually.

A differential in any automobile is described as a gear train with three gears in which the rotational speed of one shaft is equal to or a set multiple of the average speed of the others. So, if you are interested in knowing more about this amazing part of cars called Differentials then go through the article.

What Does Car Differentials mean?

It’s so common to hear words related to our cars and not even understand what they mean. In some cases, an automotive service advisor can tell a customer that the differential oil needs to be changed, but the customer doesn’t know what he means. 

In front and/or rear axle assemblies, differentials are part of the axle assembly.  Wheels on a vehicle rotate around the axle, which is the central shaft.  Automatic transmission with a four-wheel drive is shown car differentials perform well in the car.

Reasons behind using Car Differentials in your automobiles

The differential allows vehicles to rotate at different speeds when they are turning because different drive wheels like the wheels that receive power from the engine are on the same axle. Similarly, differentials change the direction of rotating driveshafts; for example, in a rear-wheel-drive car with a longitudinal driveshaft, the drive shaft joins and transfers power to a perpendicular axle that drives the left and right wheels.

Oil changes and/or inspections are recommended at regular intervals for differentials, which are typically low-maintenance, sealed components. There can be two or more differentials on a four-wheel-drive car. There can be vibrations, binding during turns, and sounds ranging from clunking to howling if the differential fails.

For instance, when your car turns a corner, the outer wheel has to move more quickly than the inner one. Both wheels receive the same amount of torque from the differential. As a result, the wheel will be able to respond to resistance or create traction, creating more torque as the wheel rotates. Wheels revolve faster and have less resistance when they are turned.

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History related to Car Differentials

There was a common problem with wagons, chariots, and carts before the development of the differentials in the cars, including one of the front or back wheels slipping or dragging when turning around a corner. The right methods for enabling engine-powered wheels positioned on the same axle to revolve independently of one another were a new challenge brought on by the industrial revolution.

In the original automobile designs, there was no way to solve the problem of powering each wheel individually, so each wheel was powered independently. The wheels were frequently underpowered and frequently lost traction on surfaces other than firm, level ground, thus having two sets of front and rear differentials were far from the optimal solution. Finally, the open differential – from which all other differential systems are derived – was developed by a French watchmaker in the middle of the 18th Century.

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Basic functions of Differentials in an automobile

The differential allows the steering wheels to turn at different speeds, thus allowing the automobile to turn without putting too much pressure on its tires. There is a smaller distance between the interior and exterior wheels when compared to the outside wheels.

  • In general, automobiles have either a front-wheel-drive system or a rear-wheel-drive system. A trailing pair of wheels move independently and receives power from the engine in either the front two wheels or the rear wheels since a trailing pair of wheels is trailing and moving independently.
  • The power from the engine might have been transmitted directly to the two wheels without the need of a differential in the event that the automobile could only go in a straight line. The opposite is true, and the inner wheel has to revolve less than the outside wheels when you maneuver the automobile around a corner.
  • It is, therefore, the differential’s job to limit this fluctuation of the wheel’s center of gravity and to prevent sliding by allowing the outer wheel to rotate more than the inner wheel in order to accommodate this fluctuation. A differential would have prevented the vehicle from going through the bend without slipping if it had not been for the differential.

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Various Types of Car Differentials

The various types of car differentials are mentioned below:-

Open Car Differential

It is the open differential unit that is the simplest and most commonly used type of differential system. The reason for its name is that the wheels can always rotate independently. There is one huge disadvantage to this type of wheel, and that is the fact that if it loses traction, such as by hitting the ice, it will still be getting a lot of power, and it will be spinning helplessly, and you will not be able to go anywhere. 

All new cars must include traction and electronic stability control in order to counteract traction loss and inherent stability while driving. These gauges if a wheel is spinning more quickly using sensors on the anti-lock brakes. Then, to regain control, it either lowers engine power, stops the spinning wheel, or does both.

You might want the car’s wheels to spin at times, for example, when trying to get out of deep snow, in which case you can disable traction control temporarily by pressing the traction button.

Benefits of using the Open Car DifferentialsDrawbacks of using the Open Car differentials
●     There are different wheel speeds on the same axle, which means the outer tire will travel further in a corner when you go around the corner, so there will be no wheel slip when you will be traveling around the corner.   The differential system will be more efficient from the standpoint of energy loss compared to other types of systems from the standpoint of efficiency. As a result of reduced traction on one wheel, the vehicle is unable to produce as much power as it would usually do when the wheel is not sliding. There is a probability that both wheels will receive a small amount of torque if one wheel is unable to dissipate the same amount of power.
Open Car Differential

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Limited-Slip Car Differentials

A limited-slip differential is used in some cars instead of an open differential, notably in performance versions. Power is transferred to the opposite wheel when one wheel loses traction.

It is because of this feature that wheel spin is reduced and, in a foreword wheel drive vehicle with more power, torque steering is also not generated. Torque steering occurs when a front driver pulls from side to side when stepping on the accelerator.

The purpose of limited receipts is the same no matter what type they are, however, the way that they accomplish it differs from one kind to another. In a mechanical-clutch differential, clutch plates are located next to the gears, and pressure rings apply pressure to the plates to provide resistance as needed. The same principles apply to active differential systems, which employ a computer to monitor traffic conditions and activate the differential’s grip.

Benefits of using Limited-Slip DifferentialsDrawbacks of using Limited-Slip Differentials
By using an axle with different wheel speeds, you can reduce tire wear on one axle as compared to an axle with only one wheel speed.  The wheel is also able to send torque more efficiently with more traction power due to this feature.    
A lot of people like this Limited Slip Differential because it offers very smooth operation, does not have the low-speed clunkiness common to other types of Low Slip Differentials that navigate tight spaces, and is easy to use.  
In order for the torque to be transferred between the two sides, it is necessary for the two sides to have a speed difference between them.   The effect of the Limited Slip Differential is diminished when it is applied too frequently as a result of its excessive use of it.
Limited-Slip Car Differentials

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Viscous Limited-Slip Car Differential

This is a type of limited-slip differential, and it relies on the use of a thick liquid to create the necessary resistance for it to be able to switch between open and closed states without altering the mechanics of the differential. With fewer parts than a mechanical Limited-Slip Differentials, it becomes an advantage when compared with a mechanical Limited-Slip Differentials.

In order to increase the resistance of a wheel, a viscous fluid needs to be heated up as it spins. This slows down the spinning wheel at the same time as redistributing the torque to the wheel that has grip because of the slowing effect. There are a number of reasons why Viscious Limited Slip Differentials are more efficient at producing torque to the wheel that has more traction than other CVTs.

Benefits of using Viscious Limited-Slip Car Differentials Drawbacks of using Viscious Limited-Slip Car Differentials
In contrast to other differentials, electronic LSDs develop resistance in tandem with wheel speed, providing very gradual traction increases in comparison with mechanical LSDs. A VLSD is also capable of directing torque to more traction-oriented wheels. As torque is channeled from the drive shaft to the slow spinning wheel, fluid acts as a resistance. The faster wheel experiences more resistance when it loses traction and spins when the differential creates a speed difference between the two wheels.  There is a tendency for VLSDs to lose some effectiveness with prolonged use, as the fluid becomes less viscous when it is heated, thus reducing resistance. In addition, it does not provide absolute resistance within a large enough space to lock properly, like a mechanical LSD.   As long as the outer wheel is moving faster than the inner wheel, mechanical and viscous LSDs can suffer from traction loss during high speed cornering, which may result in torque loss during high speed cornering. Over steer and under steer occur at the wrong moments as torque is injected into the inner wheel.  
Viscous Limited-Slip Car Differential

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Mechanical Limited-Slip Car Differentials

The Mechanical clutch Limited-Slip Differentials has two pressure rings and the same basic gearing as open differentials. Two sets of clutch plates that are positioned next to the gears are under pressure from the pressure rings. This offers resistance to the wheels’ independent rotation, switching the differential’s impact from open to locked. Additionally, it gives it more traction.

The pressure rings encircling the core gears in this type of mechanical clutch Limited-Slip Differentials are driven apart by the centre gear pins. Under rotation, it pushes against the angled surfaces and forces the pressure rings into either side of the clutch park yellow and blue. As a result, there is resistance created, and the operating of the axle is altered to have a fixed effect.

There are a number of subtypes of mechanical clutch Limited-Slip Differentials that are further divided into different subtypes based on their mechanisms. As the clutch plates and pressure ring are pressed against one another, they will change when the pressure is exerted on them.

Active Car Differentials

The active differentials have many similarities to limited slip differentials because they also employ mechanisms. The mechanism provides the resistance that is necessary for torque to be transferred from one side to the other. Unlike conventional clutches, which rely solely on a mechanical force to operate, electronic clutches are activated electronically.

As a result of the changing driving conditions, active differentials use electronics to artificially alter the mechanical forces encountered by the system. This is the reason why they are capable of being controlled and, therefore, programmable. Computers that are equipped with sensors can automatically determine to which wheels power should be transferred and when it should be transferred.

These differentials improve vehicles that can withstand often changing driving conditions and perform well, particularly on poor roads. However, this technology will be able to maintain their ongoing vehicle modifications.

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Locking Car Differentials

The clutch and springs in these types of differentials are used to actuate the lock to send the same amount of power to each wheel no matter how much traction the car has, regardless of the condition of the traction. An axle of this type essentially forms a solid part of the vehicle.

As a result of the locking differential, the full amount of torque is always available to both wheels, so the amount of torque is no longer limited by the lack of traction of a single wheel. This grants greater traction as a result of the locking differential.

When going up higher speeds, this may be a disadvantage, but if one is off-roading or climbing in the mountains, it will be a great advantage. Almost every off-road vehicle and some performance cars use them, and some of them are found on off-road vehicles.

Benefits of using Locking Car DifferentialsDrawbacks of using Locking Car Differentials
As a result, more torque can be provided up to the wheel, resulting in increased traction. At any given surface condition, this will allow most of the torque to reach the ground in various designs.   In addition to its robustness, simplicity, and efficiency, it is also very cost-effective.   When a drift situation arises in which the wheel speed on each axle is to be kept constant as much as possible, this method provides a solution.  There is one disadvantage of the locking differential, which is that the right and left wheels cannot rotate at different speeds. In addition to the increased tire wear, this also results in a tying up of the drivetrain.

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Torque-Vectoring Car Differentials

The differential used in this type of vehicle is controlled electronically by a set of sensors and electronic devices that receive information from a variety of sources in order to act upon an electronically actuated clutch and a controller.

They function in the most effective way, providing a driving experience that is genuinely dynamic and high-performance. High-performance rear-wheel drive and all-wheel drive cars exhibit different torque vectoring.

Benefits of using Torque-Vectoring Differential  Drawbacks of using Torque-Vectoring Differential
As the outer wheel gets closer to the turn, this will allow it to send a greater amount of torque to the inner wheel.   It gives the designer total control; instead of being reactive, the system can decide when to deliver extra torque to a particular wheel under what circumstances.   As much as 100% of the potential torque can be transmitted to the wheel using this type of system.It does not have any disadvantages, but there are a couple of things that are worth mentioning, which are its complexity and its cost.

Torsen Car Differentials

A torque-sensing device is known as a Torsen. Limited-slip differentials are differentials that function without a clutch or fluid resistance by utilizing some accelerated gearing.

Open differentials can be made to work this way by adding worm gears to the conventional gear setup. On each axle, worm gears provide the resistance that allows torque to be transferred.

As a result, the worm gears are continually meshing with each other through the connection of spur gears. As a result of the continuous mesh between the two sides of the differential, the differential has the advantage of delivering quick torque, making it highly responsive to changes in road conditions and driver behavior.

Benefits of using Torsen Car DifferentialDrawbacks of using Torsen Car Differential
●     The faster wheel will receive more torque as soon as there is a speed difference between them, as soon as a speed differential exists between them. In addition, it reacts much faster than LSD in terms of its reaction time.   Since differential action depends on fiction throughout the gears, these systems don’t need regular maintenance.      In order for differential action to take place, friction throughout the gearing system is required, so these systems do not require regular maintenance.

This is how various Differentials in an automobile function

A differential is nothing but a device that sends torque from an engine to the wheels. The differential distributes the engine’s power so that the wheels may spin at various speeds. You won’t have any issues if you rotate it around a corner because each wheel may revolve independently of the others.

A complete contemporary differential appears to be immensely complex when viewed as its whole. However, if you carefully dissect it and comprehend the fundamentals of what it is attempting to do and how it is doing so, you will discover that it is truly a lovely thing.

Open Differential workings

When a car is traveling straight down a road, it is necessary for both drive wheels to spin at the same speed. The input pinion, since neither of the pinions on the side gears inside the cage is spinning, effectively locks both side gears onto the cage as the cage and ring gear are rotated while the input pinion is acting as a lockout.

This is the last gear reduction in the automobile, therefore take note that the input pinion is a smaller gear than the ring gear. You may have come across phrases like final drive ratio or rear axle ratio. These speak of the differential’s gear ratio. The ring gear has 4.10 times as many teeth as the input pinion gear if the final drive ratio is 4.10.

When a car makes a turn, the wheels must spin at different speeds, and that’s how the turning is possible. When the car starts turning, the pinions in the cage start spinning, enabling different speeds to be reached by the wheels. The outside wheel rotates more quickly than the interior wheel, which rotates more slowly than the cage, and that is how you can turn the vehicle. 

Limited Slip Differential workings

If you are on the track and you are trying to go around a tight corner at an average speed, you might experience some difficulty. The path of least resistance will be taken by all of this power. As all weight is shifted to one side, the power becomes concentrated on the inner wheel, resulting in a great deal of power loss or spinning, causing the vehicle to crash.

To reduce this drive loss, these kinds of differentials are placed. To ensure that each wheel receives the necessary amount of power, a clutch system generates friction on both sides of the axle. If you know how to operate the steering wheel, you can maneuver the vehicle over a curve with nothing but force.

There is a tremendous force acting on the entire differential mechanism during differential operation. One of the reasons these components are made from materials that have the highest degree of strength is because of this reason. The differential must be extremely durable in order to last a long time. A cheaper metal could be used when cars were slower and less demanding, so you could get away with using lighter metals.

Workings of Viscous Coupling Differentials

The viscous coupling is frequently encountered in automobiles with all-wheel drive. In order to switch power to the other set of wheels when one set of tires begins to slide, it is frequently utilized to connect the back wheels to the front wheels.

As seen in the illustration below, the viscous coupling contains two sets of plates inside a sealed enclosure that is filled with a viscous fluid. Each output shaft is attached to a single pair of plates. Both sets of plates and the viscous fluid spin at the same rate under typical circumstances.

The set of plates corresponding to one set of wheels spins faster than the other when that wheelset seeks to spin faster, maybe because it is slipping. The slower discs are dragged along as the viscous fluid, wedged between the plates, strives to catch up with the quicker discs. This distributes greater torque to the wheels that are going more slowly and are not sliding.

The speed differential between the wheels is less noticeable while a car is turning than it is when one of the wheels is sliding. The viscous coupling transfers greater torque when the plates are spinning more quickly in relation to one another. Because of how little torque is imparted during a turn, the connection does not obstruct turns. This also reveals a drawback of the viscous coupling, which is that no torque will be transferred until a wheel really slips.

Torsen Differential

Electronics, clutches, and viscous fluids are not present in the Torsen differential, which is completely mechanical. When the torque applied to each wheel is the same, the Torsen acts as an open differential. The Torsen differential’s gears bind together due to the difference in torque as soon as one tire begins to lose traction. Differential gear configurations is determined by torque biased ratios.

In high-performance all-wheel-drive cars, these components are frequently employed. They’re frequently utilized to distribute power between the front and back wheels, much like viscous couplings. The Torsen coupling performs torque transfer to the stable wheels prior to the slippage, making it preferable to the viscous coupling in this application.

The Torsen differential will, however, be unable to provide any torque to the opposite set of wheels if one set of wheels entirely loses traction. The bias ratio, which is five times zero, regulates the amount of torque that may be imparted.

Various Parts available in the differential of an automobile

Differential systems are composed of the following components that are mentioned below:-

Side or Sun Differential Gears

Differentials are composed of a small bevel gear called differential side gears or sun gears. Axle inner ends are mounted with this device. This arrangement combines both the driving and driven shafts at 90 degrees by means of two bevel gears.

Cross Pins

This shaft is used to support the pinion gears, also known as the pinion shaft. There is a differential case in which it exists. 

Axle Shaft

Solid shafts make up axle shafts and are located between differentials and gear sets in axle housings. Using it, the wheels attached to the axles transfer rotational force to the transmission system.

Crown Wheel

In addition to ring gears, crown wheels are also sometimes referred to as ring gears. During operation, they work as equalizers distributing the torque between the two driving wheels while allowing one of them to turn faster than the other as a result.

Drive Pinion

In the differential case or carrier there is a differential housing that encloses the differential. By means of a universal joint and a ring gear, the driver shaft is connected to the drive pinion. In this way, the drive pinion rotates when the shaft is rotated, and therefore the ring gear rotates as well.

Planet Gears

Planetary gears are an crucial component found in differentials. The differential system rotates around the common axis of the sun and ring gear as the axles of the planetary gears do the same.


Two-wheel axles are attached to a differential case, as well as differential side gears that are attached to the differential case. This type of bearing consists of two axle shafts that are rotated by bearings.

Why Caring for your car Differential is necessary?

Few people pay attention to the simple difference when doing routine maintenance on cars. It is discretely hidden and doing an excellent job—until it doesn’t.

It is instantly clear why maintaining a car diff in top condition when you consider how essential it is to a vehicle’s operation. After all, your automobile wouldn’t be able to turn well without a differential.

Differential fluid can get soiled and polluted over time. It is dangerous to keep driving with polluted differential fluid since it might cause parts to wear out prematurely. In the worst situation, tainted fluid may result in long-term harm to the vehicle.

Symptoms of having a problematic Differentials in your automobile

You can take steps to avoid any real damage from occurring to your car by learning the warning signs of car diff problems as soon as they appear. As soon as you notice any of these symptoms, you should get your differential serviced right away:-

  • When your vehicle is making a whining noise while accelerating it.
  • When deceleration is accompanied by a whirring sound.
  • During speeding, you may hear a rumbling or whirring sound at the steering wheel.
  • When approximately every metre, a clanking sound is heard.
  • As a vehicle turns a corner, a banging sound is heard.
  • In addition to worn u-joints and out-of-balance driveshafts, a steady vibration can also be caused by worn u-joints.
  • If your vehicle clunks when you start moving or step on/off the gas, chances are that you have loose yokes, bad u-joints, a worn transmission or transfer case.Get started in your dream career today with 60% off registration at IAP Career College.

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