Is it worth installing a self-locking differential on a field?

Location

On vehicles with a single drive axle, the differential is located on the drive axle.

Tandem axle vehicles have two differentials, one on each axle.

On vehicles with all-wheel drive, there is one differential on each axle. It is not recommended to drive such vehicles on hard-paved roads with all-wheel drive engaged.

On cars with permanent all-wheel drive, there are three differentials: one on each axle (axle-axle), plus one that distributes torque between the axles (axle-axle).

With three or four driving axles (wheel arrangement 6 × 6 or 8 × 8), an inter-vehicle differential is also added.

Transfer case operating modes

All about mud tires on Chevrolet Niva

This mechanism can operate in five modes:

• Neutral is on.
• The differential is unlocked when the "lowering" is turned off. In this case, the torque is distributed in a ratio of one to two.
• The differential is locked when overdrive is engaged. Here, torque distribution is carried out automatically, depending on the quality of wheel grip on the road.
• Downshift is engaged and the differential lock is disabled. The transfer of forces occurs in the same ratio as in the first case.
• The differential is locked and the gearbox is engaged. In this case, all axles are rigidly locked together, including the axle shafts. Torque is produced unevenly, depending on the type of road surface (dirt, sand, etc.). In this mode of operation, the best cross-country ability of the vehicle is achieved. But driving with a constantly engaged downshift and with locks will not work. This increases the load on the transfer case bearings. The Chevrolet Niva will soon require serious intervention in the transmission. Fuel consumption also increases significantly, which greatly eats up the tires.

The problem of a slipping wheel

A conventional ("free") differential works fine as long as the drive wheels are inextricably connected to the road. But when one of the wheels loses traction (finds itself in the air or on ice), then it is this wheel that rotates, while the other, standing on solid ground, is motionless. If one of the wheels loses traction, its resistance to rotation drops, and rotation occurs without a significant increase in the moment of resistance (sliding friction in the contact patch is less than static friction and does not significantly depend on the slipping speed). At the moment when the wheel begins to slip, the torques on the wheels are not equal to each other, but are inversely proportional to the resistance to rotation of the wheels.

When the car moves in a straight line, the satellites do not rotate relative to their own axis. But each, like an equal-arm lever, divides the torque of the main drive driven gear equally between the axle gears. When a car moves along a curved path, the inner wheel with respect to the center of the circle described by the car rotates more slowly, the outer wheel rotates faster - while the satellites rotate around their axis, running around the gears of the axle shafts. But the principle of dividing the torque equally between the wheels remains the same. The power supplied to the wheels is redistributed, because it is equal to the product of the torque and the angular velocity of the wheel. If the turning radius is so tight that the inside wheel stops, then the outside wheel rotates at twice the speed as when the car is moving in a straight line. So, the differential does not change the torque, but redistributes the power between the wheels. The latter is always larger on the wheel that rotates faster.

How to do

The easiest way is to permanently lock the differential completely. But such a homemade blocking is acceptable for cars driving only off-road. For example, for rally-raid cars. To implement the idea, you need to remove the unit equipped with the differential and disassemble it. Then weld the satellites to the axles. Fixing the gears will allow the mechanism to divide the rotation speed between the axle shafts only in a proportion of 50 to 50.

Making a limited slip differential with your own hands is a little more difficult than simply fixing the satellites. But such a modernization will not only improve the vehicle’s maneuverability in mud and snow, but will also not change the operation of the unit on hard surfaces. One version of such a device can be assembled from two brass or bronze bushings and a spring. Their sizes will depend on which vehicle transmission you are upgrading. Therefore, work begins with removing the assembly and disassembling the planetary gear. After this, you can take measurements, order the production of bushings and select a spring of suitable dimensions.

You will find out whether it is stiff enough after assembly by testing your homemade product. The spring is designed to press the pinion gears against the differential housing. Because of this, under the influence of friction, the satellites will rotate more slowly around their axis. The greater the friction force, the more evenly the speed of rotation of the driveshaft will be divided between the axle shafts. Metal bushings are needed to prevent contact of the satellites with the spring.

Of course, installing a factory-made differential lock is easier and the result of such an upgrade is better. However, it is expensive and practically eliminates creativity from the process. The cost of “self-blocks” for cars of the VAZ family is slightly less than 12 thousand rubles. But their installation requires only care and accuracy. There is no need for a special tool.

Peculiarities

Just because a vehicle comes with all-wheel drive does not mean it has all-terrain capabilities. Often, due to their design features, SUVs fall into the treacherous traps of sandy and washed-out roads. Domestic cars are far from an exception. There is an assumption that the self-locking differential on the Niva will be an important addition, especially if the owner plans to actively use the car in off-road conditions.

The limited slip differential, or self-block, as the part in question is also called, provides wheel stop automatically at the required time interval. It can be described as an intermediate option between the free analogue and complete blocking. The capabilities of both devices are optimally combined in the self-block.

Assembly of the unit

When you have decided on the best self-locking differential for the Niva, you can begin assembling the unit. Initially, they adjust the gaps, which is not so simple. For this purpose, special washers of different thicknesses are used. Alternatively, accuracy is determined using a steelyard. One edge of the cord (about a meter in length) is wound around the flange, and the second is fixed to the scales. Pull the device in the winding, not forgetting to mark the turning point.

To ensure correct functioning of the gearbox, the elements are sealed before assembling the parts. If this is not done, soon after installation defects may appear, even to the point of complete breakdown of some parts. After treating the surfaces with sealant, wait until it dries completely. Next, the gearbox is filled with new oil. All sealing components with deformations and a hint of leakage are replaced. The mechanisms are assembled in a mirror order. After the replacement and installation of parts is completed, you should check the operation of the brake unit. This is very important, since malfunction of parts affects road safety.

Turning the electric lock on and off.

Manual activation of the lock is possible by pressing and holding the button until the lock indicator turns on. Manual shutdown is done in the same way - by pressing a button.

Attention! Engage with the vehicle stationary or at speeds up to three miles per hour with minimal slippage. Switching on at a higher speed may damage the locking mechanism with subsequent denial of warranty repairs.

We will deny warranty if the locking coupling or pins are damaged. After passing a difficult section, the blocking must be turned off.

On the Chevrolet Niva it is possible to turn on all three differentials at the same time

. Thanks to this, the vehicle’s cross-country ability increases several times when driving off-road.

. In this case, when the driver turns on the forced locking, the wheels “become” connected to each other. This helps ensure that they rotate evenly.

Differential assembly

If the center lock is forcibly engaged, then the front ones are also rigidly connected at once, which guarantees an even distribution of traction to all four wheels. Thus, the vehicle’s cross-country ability will be increased several times.

, which makes the Chevrolet Niva a real SUV.

Not all cars are equipped with blockers, and therefore they will be vulnerable off-road. In this regard, Chevrolet is a unique car that can move with both one-wheel drive and all-wheel drive.

, which allows him to feel confident even on mountain roads.

Forced blocking should be enabled in the following cases:

1. When overcoming difficult sections of the route. In this case, the blocking should be turned on in advance, even before leaving for such an area.
2. On steep climbs or slopes when wheel slip is possible.
3. When driving on sand.
4. When driving on snow or ice.

When the Niva moves on a regular road with a smooth surface, it will not need to lock all wheels. They will adhere normally to the surface and not slip, since the traction force from the engine will be distributed evenly over them. For this reason, when the car is moving on a good road where the wheels will not slip, the use of a differential will not be required.

Also interesting: Niva engine purchase || Niva engine interchangeability

Optimization of the technical condition of the unit

The Niva's configuration includes the installation of a differential for driving on roads with standard surfaces. If the “iron horse” is intended to be used as an SUV, then modifications will be needed. Under standard operating conditions on the Niva, torque is automatically supplied to the axis where there is a lack of torque. For comfortable off-road driving, it is necessary to transmit torque to all wheels in an equal amount.

It will help to become familiar with how to use the torque transfer case. If you have the necessary knowledge, optimization is carried out in-house. The technically correct scheme of actions is as follows:

Installation of a forced system operating in automatic mode. Its strengths include its ability to withstand the test of severe off-road conditions. A forced differential locking system is installed only if the vehicle is used most of the time on roads with unsatisfactory surfaces.

Experienced drivers recommend following these tips. If you install the system without taking into account the specifics of movement, then there is a high probability of increased wear of the vehicle’s chassis. It would be useful for those who are just planning to acquire a personal car to understand the difference between the two concepts.

The interwheel unit of the Niva Chevrolet transmits torque between the left and right wheels. The system only works within the bridge where it was installed. The interaxle block of the car is a dynamic transfer of torque between the rear and front axles.

In the “default” mode, the manufacturer installs only one type of differential lock on manufactured vehicles. Before purchasing, you must clarify this detail using the technical description. It must be remembered that using everything at once is strictly prohibited. A Chevrolet Niva car provides for the safe use of only one type of lock.

Device

The basis of any differential can only be a planetary gear, which, due to the mechanics of its operation, is the only one of all rotational motion gears that can solve the problems facing a differential in a transmission. The term “planetary differential” is redundant - any differential is planetary. Its performance as a differential absolutely does not depend on its composition or shape, or on the choice of specific links for driving or driven. Any in its simplest version - a three-link planetary mechanism without any control elements - can perform the functions of decomposing one flow into two interconnected ones or adding two independent flows into one. The choice of other links as leading ones, and others as driven ones, is determined only by the required kinematics of the differential’s connections with other transmission elements and the peculiarities of the mechanics of the differential operation in the chosen format of distribution of functions between the links. The addition of control elements and the use of so-called complex planetary mechanisms gives the differential the ability to mutually equalize the angular velocities of flows and the ability to actively control these velocities.

Sectional view of the differential of a Porsche Cayenne

The canonical, most famous type of differential is the cross-axle differential of a car, made on the basis of a simple (that is, three-link) spatial planetary mechanism of a circuit with four bevel gears. The planetary carrier of such a differential actually serves as its entire body - this is the driving link ➁. The two gears are satellites on a common axis ➂. And the two gears are two suns - two driven links ➃. Power is supplied to the housing (carrier) through a rigidly fixed driven gear of the main transmission, which in turn is paired with the drive gear ➀ formally there is another element of the transmission, despite the fact that the differential with the driven gear often looks like a single assembly unit. Power is removed from two suns, to which in this case shafts with CV joints are attached.

Types of automobile differentials

In addition to bevel, cylindrical and worm, the following types of differentials exist and are successfully used: fully locking differential, Thorsen differential, Quaife differential, viscous coupling.

Full lock differential

This type of differential is most often used on trucks and SUVs. Their blocking is activated and deactivated directly from the passenger compartment using a special key by the driver. They are used to improve the cross-country ability of vehicles.

Center differential with Torsen type locking

The design of the working drive of this system consists of the following units:

1. frame;
2. right side gear;
3. left side gear;
4. satellites of the right and left side gears;
5. output shafts.

It is worth noting that the Torsen differential has the most advanced design.

Principle of operation:

The Torsen center differential lock consists of driven and driven worm wheels, otherwise called axle shafts and satellites. In such a system, blocking occurs due to the peculiarities of the functioning of gears of this type. In normal condition, they are given a certain gear ratio. If the wheels have good grip and move smoothly, the differential operates in exactly the same way as a symmetrical one. But as soon as there is a sharp increase in torque, the satellite tries to start moving in the opposite direction. The side worm gear is overloaded and the output shafts are blocked. In this case, the excess engine torque is transferred to the other axis. The maximum degree of torque redistribution for Torsen differentials is 75 to 25.

The most famous version of this system is Torsen Audi Quattro. This is one of the most popular mechanisms in the designs of modern all-wheel drive vehicles. Its undeniable advantages are a wide range of torque transfer, instant response speed and the absence of a negative impact on the braking system. But the disadvantages include the complexity of the design with all the attendant consequences.

Advantages of differentials of this design

This design has many advantages. This mechanism is installed because the accuracy of its operation is extremely high, while the device operates very smoothly and quietly. Power is distributed between the wheels and axles automatically - no driver intervention is required. Redistribution of torque does not affect braking in any way. If the differential is operated correctly, then there is no need to service it - the driver is only required to check and periodically change the oil.

This is why many drivers install the Thorsen differential on the Niva. It also uses a permanent all-wheel drive system and no electronics, so extreme sports enthusiasts often replace the standard differential with this unit.

Flaws

There are also disadvantages. This is a high price, because the structure inside is quite complex. Since the differential operates on the thorn principle, this increases fuel consumption. Despite all the advantages, the efficiency is quite low when compared with similar systems of another type. The mechanism is highly prone to jamming, and the wear of internal elements is quite intense. Special products are needed for lubrication, since a lot of heat is generated when the unit operates. If different wheels are installed on the same axle, the parts wear out even more intensively.

Quaife differentials

A distinctive feature of differentials of this type is that the satellites in them are located parallel to the axis of rotation of the housing (bowl), and in two rows. In addition, during the operation of these units, friction forces are generated, which, if necessary, automatically block and increase the vehicle's maneuverability and traction force. Most often, Quaife differentials are used for tuning cars and SUVs.

Viscous coupling

The operation of this type of differential is based on the same principle as the operation of a torque converter. Most often, viscous couplings are used in cars with all-wheel drive and are used to ensure the connection of the front wheels with the rear wheels according to the following principle: if one of them slips, then the torque is transmitted to the others, thereby solving the problem of slipping. Structurally, a viscous coupling is a cylinder in which there is a package of perforated metal disks immersed in a viscous liquid and connected to shafts (both driving and driven). Depending on the temperature, the viscosity of the liquid changes, which is what the operating principle of this unit is based on.

Differential lock on Niva (self-block): bringing the car to perfection

Content

1. What are we dealing with?
2. Coefficient, preload and other nuances
3. Types of blocking on Niva

• Limited slip self-block (LSD)
• Forced blocking

• How to decide what to install?

What are we dealing with?

What is a differential or as it is sometimes abbreviated as “diff”.
Why is it needed?! The Latin word “differentia” and the similar English word “different” are translated into Russian almost identically: “difference” or “different”. There is another definition of differential - planetary gear. The purpose of this element is to transmit the power of the power unit through rotation without losing it on the axle shaft with the wheels attached to them. The differential causes them to rotate at different speeds depending on driving conditions. Inside a turn, the wheel makes much fewer revolutions than one that goes along a long radius. If in place of the “planetary” there was an ordinary solid axle, the probable parasitic circulation of power would guarantee a decrease in control over the car, loss of traction with asphalt, significant wear of the transmission, incredible fuel consumption, etc. The differential “links” the drive of one axle, removes the “parasitic” phenomenon, without loss of power.

An interwheel differential is present in almost all cars. It is usually located on the drive axle. There may be two or more axes to which the planetary gear distributes the incoming power flow.

Read also:  Replacing the internal door lock on VAZ 2113, 2114 and 2115

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Coefficient, preload and other nuances

The Niva 2121 is equipped with permanent all-wheel drive, and therefore, in addition to two inter-wheel differentials, it has a third - an inter-axle differential, distributing the moment between the front and rear.

A regular “free” differential is not always enough for a Niva owner. An SUV is bought to drive like a mother-in-law on different terrain and surfaces: dirt, snow, ice, etc. Often a car ends up with two wheels on a grippy surface and the other side on a slippery texture. In such a situation it is easy to “lose” him. Blocking will allow you not to worry about this.

When choosing a block, you need to take into account two important points - blocking coefficient and preload. The first denotes the ratio of torque on the lagging wheel with good grip and on the leading wheel, which has already lost contact with the road. A free differential has a coefficient of 1. For self-locking ones, it is up to five. That is, the lagging wheel will receive 5 times more torque. This parameter is sometimes indicated in %. For worm gears it is determined by the inclination of the teeth, for disk drives it is determined by the configuration of the friction clutches.

And preload is a certain moment of blocking inside the body of the product even before the moment when it may be required. Mostly in modern self-blocks, preload is created by washers. It can be customized to suit almost any driver's requirements. The washers can be replaced as they wear out, and the differential will continue to serve faithfully for many more years. While the teeth of the “worm” and the clutches of the “disc” design wear out sooner or later, the preload decreases.

True, it is important not to “overdo it” here - excessive preload greatly increases the load on the differential itself and increases the wear of all transmission elements.

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Types of blocking on Niva

“Native” differentials can be replaced with a self-locking analogue of increased friction or with a device where the “planetary gear” is locked forcibly. For those who want to install a self-block on a Niva themselves, we will try to thoroughly explain the difference between a worm, screw or disk lock. Let’s evaluate each design that works “from the button.”

Limited slip self-block (LSD)

A limited slip differential or limited slip differential is installed on various sports cars. Many companies have been mass-producing such things in Russia for a long time and in large quantities. It initially has limited slip. This thing independently equalizes angular velocities. It essentially serves as a direct transmission, as if the power is transferred to a single “stick” on which two wheels rotate equally. Can also be installed on a Niva 2124 car.

LSDs are distinguished by the response format - from the occurrence of a difference in angular speeds (disc) or when the torque changes (screw).

Disk lock

There are many options for implementing such a lock, but they all have a common principle - the differential here is equipped with two sets of discs. As soon as slipping occurs, the clutches compress and equalize the angular velocities. The discs are similar to automatic transmission clutches. They do not interfere in any way with the civilian operation of the car. The preload here is created by a spring or conical rings.

The SV-PARTS store offers locking for everyday driving on the Niva for axle shafts with 22 or 24 splines:

This makes it possible to use this product even on the good old Niva, produced by AVTOVAZ, or on its “younger” sister – Chevrolet Niva:

Self-locking disc differential VAZ 2123 (24 splines)

Art. SDS.23

14460.00

— +

Buy

For convenience, you can purchase a rear axle gearbox assembled with any lock, like this self-block with a 4.1 main pair:

Rear axle gearbox main pair 4.1 (2103) screw locking (22 sh.) SV-PARTS

Art. SV.03.00031752

14040.00

— +

Buy

Those who like to push themselves will be more pleased with SV-PARTS. It looks like a normal differential. Housing, two covers, 10 satellites inside (5 for each wheel). Plus a gear that blocks one drive relative to the other, and preload washers.

Self-locking differential for VAZ 2101-2107, 2121 screw 3-piece (22 splines) SV-PARTS

Art. SV.01.2403018

8050.00

— +

Buy

The product “stands up” without any modifications. Can be used on cars of the classic VAZ family. The design is distinguished by washers placed outside and a modified inclination of the teeth. Careful adjustment of the elements ensures a service life of 120 thousand kilometers. The car will be able to compete in drifting, rallycross, or, in the case of the Niva, in competitions such as Off Road.

Worm self-block

The worm gear design is named after its main principle - sensitivity to torque. In English it is "torque sensitive", which defines the term Torsen. These self-blocks have been widely known since the last century. In them, the satellites are replaced by a “worm” - an irreversible transmission that transmits torque exclusively from the “worm” to the semi-axial gear.

There's no way the worm can turn the wheel here. In normal modes, the design easily works like an ordinary free differential, but as soon as one of the wheels hints at slipping, the locking is instantly activated and does not physically allow even the slightest idle rotation of the second wheel.

Screw block

Worm and screw locks are often confused, since the screw lock is the same Torsen product, but in a more modern design. It is simpler in many ways and quite popular. Essentially, this is a worm gear with a longitudinal arrangement. Its design feature ensures the occurrence of several friction pairs at once. The worms expand in such a way that they close both lengthwise and crosswise.

This unpretentious lock for the Niva 2121 easily replaces the standard planetary gear. It blocks the wheels by 70%, but that's enough. Preload is created by springs inside the housing. As they wear out, the lock does not lose its properties - it is simply connected a little later. It is important to take into account only one thing - it is practically useless when hung diagonally.

Self-locking differential for VAZ 2101-2107, 2121 screw Avtosprinter

Art. AS.01.00072620

7500.00

— +

Buy

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An example of such a thing is a blocking produced by VAL-Racing in the rear axle or front gearbox of a Niva 21213 produced before 2002, as well as in the rear axle of a Niva Chevrolet:

Self-locking screw differential VAZ 2101-2107, 21213 VAL-racing

Art. 21010-2403018-00

13000.00

— +

Buy

In the SV-PARTS store, of course, differential locking for the Chevrolet Niva is also available:

Self-locking differential for VAZ 21214, 2123 screw 3-piece (24 splines) SV-PARTS

Art. SV.23.2303018

8050.00

— +

Buy

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Forced blocking

Such products block the differential 100% and, as the name implies, they are operated by the driver. They are distinguished from self-blocks, for example, on the Niva 21213 car, by the presence of a clutch, which is mounted in the standard differential housing. With such a thing, by the way, the “diagonal” is not scary, you just need to choose the appropriate option.

Pneumatic locking

Structurally, this is a regular free differential. It is modified by installing a pneumatic drive. Easy to install. You just need a tuned gearbox with a differential, a pneumatic release (valves and lines), a compressor with a receiver. Of course, the price is higher, but it certainly has its advantages.

For example, a reinforced four-satellite differential with forced pneumatic locking will allow you to compete in competitions. The presence of such a thing in the front and rear axles opens up the possibility of installing huge wheels. This product has been tested for more than ten years and has repeatedly confirmed its reliability. The pneumatic drive here is miniature - the whole thing fits into the gearbox housing, and therefore is reliably protected from damage. The kit includes everything you need for installation - right down to the fitting:

Forced pneumatic differential lock 21214, 2123 Niva (4 satellites, 24 splines)

Art. 21230-2303018-87

33500.00

— +

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Accordingly, there is an option for 22 splines:

Forced pneumatic differential lock 21214, 2123 Niva (4 satellites, 22 splines)

Art. 21010-2403018-87

33500.00

— +

Buy

Its service life is designed for the entire life of the car. In this case, the differential is repairable. To better understand what exactly it is, just watch the video!

There is a two-satellite option, it does not fit on the Chevrolet Niva, but is universal for the Niva 2121 and the entire classic family of VAZ cars. It is best used for relatively quiet trips out of town:

Forced pneumatic differential lock VAZ-2101, 2121. 2x satellite, 24 splines

Art. SV.23.2403018.12

19500.00

— +

Buy

Yes, SV-PARTS has two options for a ready-made pneumatic system! Both are equipped with excellent Berkut compressors, pneumatic distributors, a hose and a gun, oblique wires, as well as a set of sensors and relays:

Pneumatic system based on R17 Berkut for SUVs

Art. R17

22000.00

— +

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Electric drive

We offer an affordable and effective option - the UltraBLOCK system. The mechanism is protected from moisture and dust. It is activated by pressing one button and within 10 seconds it turns on the lock. The differential itself will not unlock, even when the power is turned off - it can only be released by pressing the button again.

Forced electric differential lock on VAZ 21214, 2123 Niva (24 splines)

Art. SV.00072638

24000.00

— +

Buy

Welding (Spool)

Finally, we present the cheapest and simplest option - “leaving”. This is a 100% rigid connection of the axes to each other. The main purpose - to ensure a stable stall of the rear wheels - will please those who like to “fall sideways” on everything. It may also be useful for those who are studying the question of which self-block is better for Niva 21214:

Rear gear differential spool VAZ 2101-2107 (22 splines) Avtosprinter

Art. AS.01.00072627

4500.00

— +

Buy

Please note that for Niva 21214 - Niva 2123 cars there is another option. Perhaps it will help you decide and install a self-blocking system on a Chevrolet Niva:

Rear gear differential spool VAZ 2101-2107 (24 splines) Avtosprinter

Art. AS.23.00072628

4500.00

— +

Buy

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How to decide what to install

A self-locking differential on the Niva or turning on the lock from a button in the cabin is an open question. Each car owner is guided, first of all, by his wallet and needs. You can safely go picking mushrooms or fishing if you equip your car with a product such as a rear axle lock on the Niva.

When a car often drives through deep ambushes in muddy roads or heavy snowfall, it is worth taking a more thorough approach to improving its characteristics. We definitely put the block at the rear, and add a screw differential to the front. In this case, the front lock on the Niva will serve as a guarantee of peace of mind and reliability - it won’t leave the fierce swamp, not a tractor, but you won’t have to worry about needing a shovel.

In order not to exhaust Niva in case of the most severe tests, it is better to install a forced lock. Or, as an option, equip the rear with a self-block, and the front, for example, with a product with a pneumatic drive.

In general, for those who periodically experience diagonal suspension on their Niva, we recommend installing a self-locking differential in both axles or, as an option, supplementing one self-locking differential with a second one with forced engagement.

In any case, we do not recommend purchasing a handheld lock with “low mileage” or “almost in use.” It’s always better to pay a little more for a new unit with a manufacturer’s warranty than to blame yourself later for insignificant savings. Moreover, now you know where to look for the best self-blocks for Niva.

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Advantages and disadvantages

To find out which is the best self-locking differential for the Niva, you need to compare the advantages and disadvantages in relation to the standard analogue of the car. The benefits include:

1. Increasing the vehicle's maneuverability on steep, sliding and bumpy surfaces.
2. There is no need to make changes to the design of the machine, since the self-block is mounted in place of the standard element. It is recommended to carry out installation work in a specialized workshop or do it yourself.
3. The mechanism in question operates automatically and does not require special training for the driver.

Disadvantages of installing a self-locking differential on a Niva:

• steering becomes tighter, which requires additional effort;
• the working life is less than that of the factory element;
• driving style changes when cornering;
• there is no complete guarantee of blocking.

Various modifications of self-blocks have their own nuances, depending on the manufacturer, type of development, and installed components.

Characteristics and selection rules

The choice of a self-locking differential is determined by the car model, its operating conditions, driving style and many other parameters. For example, a ball differential increases steering load, which actually changes the driving style of whoever is behind the wheel. This is mainly felt when making U-turns and turns, but can lead to breakdowns of transmission components.

If you approach the choice of a self-block correctly, then you need to take into account which axle of the car the mechanism will be installed on, since the number of splines for different models is different - twenty-two or twenty-four.

The marking on the device packaging will tell you whether it can be used for a given car brand. The blocking coefficient also varies: for example, 0.5 or 0.7. These numbers show the amount of torque transmitted. What to choose is up to the driver.

Active differential [ edit | edit code]

The term means any differential, the device of which allows you to redistribute power/traction on the driven links in any proportion required for a given moment of movement. This is precisely the difference between an active differential and a locked one, in which power control on the driven links is in principle impossible, and it is determined solely by the clutch forces. All active differentials have a two-channel control system and necessarily two control elements - two brakes or two clutches - that are activated upon command from external sources. All active differentials, in addition to the main planetary gear, which performs the functions of free power distribution, have a paired set of additional planetary or simple gears, which perform the function of redistributing power in their direction. Each of these paired gears is associated with its own control element. Although active differentials do not have any locking mechanisms, in fact, all active differentials are also lockable, only they do not have one symmetrical locking mode, but two asymmetrical locking modes (one for each of the two sides). In these modes, the differential control element operates without internal slipping, and the differential itself turns into an overdrive gear. On passenger cars with active differentials, these extreme modes may not be used, but they are used in the differential turning mechanisms of tracked vehicles.

Useful tips

To use the lock installed on the Niva effectively, use the following recommendations from experts:

1. When driving on good quality road surfaces, install the front transfer handle at the front and the rear at the rear.
2. The front handle is moved back if the road becomes slippery. Once the slippery area has been passed, switch the levers to normal mode.
3. If the Niva is stopped, the lock may not engage when the clutch is depressed. This occurs due to the alignment of the teeth with the gear teeth. What should you do in this case? Moving as if on a turn, engage the lock. The differential will turn and the gear teeth will come closer to the teeth. If turning off is difficult, do it while the vehicle is moving, maintaining a minimum speed and squeezing the clutch.

History of ways to solve the problem of a slipping wheel

• 1825 - Onesiphore Pecqueur (1792-1852)
  invented the differential.
• 1932 - Ferdinand Porsche began research into slip differentials.
• 1935 - collaborating with Porsche, launched a cam differential, which was subsequently used on early Volkswagen models (Type B-70)
• 1956 - the American company Packard was one of the first to begin producing models with a differential under the brand name “Twin Traction”. In the 60s, many companies began producing LSD differentials under various brand names:
• Alfa Romeo: Q2
• American Motors: Twin-Grip
• Buick: Positive Traction
• Cadillac: Controlled
• Chevrolet/GMC: Positraction
• Chrysler: Sure Grip
• Dana Corporation:Trak-Lok or Powr-Lok
• Ferrari: E-Diff
• Fiat: Viscodrive
• Ford: Equa-Lock and Traction-Lok
• International: Trak-Lok or Power-Lok
• Jeep: Trac-Lok (clutch-type mechanical), Tru-Lok (gear-type mechanical), and Vari-Lok (gerotor pump), Power Lok
• Oldsmobile: Anti-Spin
• Pontiac: Safe-T-Track
• Porsche: PSD (electro-hydraulic mechanical)
• Saab: Saab XWD eLSD
• Studebaker-Packard Corporation: Twin Traction

Self-locking differential

The term refers to any differential whose operating mechanics allow it to self-lock—that is, first of all, to equalize the angular speeds of the driven gears and turn into a direct transmission. Self-locking differentials do not require any external control systems and operate autonomously. In cars they can be used both as inter-wheel and inter-axle ones. Not used in tracked vehicles. Conventionally, all “self-blocks” can be divided into two groups: those triggered by torque and those triggered by the difference in angular speeds on the driven gears. The first group includes Quaife and Torsen differentials, differentials with disc and cone locking, and cam differentials. The second includes mechanisms consisting of a conventional differential and an automatic locking device: differentials with a viscous coupling, with a centrifugal automatic clutch (Eaton G80), differentials with friction locking and a differential pump, differentials with hydraulic resistance.

Self-locking system

Can be configured to the required switching threshold. This can be either a slight slip or uneven distribution of torque among the wheels. Such a connection is not rigid, and therefore does not place unnecessary load on the interaxial connection.

When installing a forced locking system on a Chevrolet Niva, you should remember that a constantly turned on system can put unnecessary stress on the transmission, so you should turn it on only when overcoming difficult sections of the road.

main gear

The main gear is designed to increase the torque transmitted to the drive wheels. Its structure, at first glance, is very simple - two gears. One, smaller in size, is the leader, the second, larger, is the slave. But the design of the main gear largely determines the vehicle’s traction and speed characteristics and fuel consumption.

Hypoid transmission

On rear-wheel drive cars, a hypoid final drive is used, since the torque must be transmitted to the drive wheels at an angle of 90 degrees. Why is a hypoid gear, which is more difficult to manufacture, used, and not a simple bevel gear? Yes, because with a bevel gear, its simplicity is its only advantage. But there are more disadvantages: noise, low load-bearing capacity, high location of the driveshaft (and, consequently, the transmission tunnel in the car body). In a hypoid gear, the axis of the drive gear is offset relative to the axis of the driven gear by the amount of the hypoid offset. Therefore, the driveshaft is located lower, which allows the height of the transmission tunnel to be reduced. This lowers the vehicle's center of gravity, thereby improving its stability.

Gear teeth are made oblique or curved. Due to the fact that in a hypoid gear there are more teeth in mesh at the same time than in a bevel gear, its smooth and silent operation is ensured and the load capacity is increased. However, due to the tighter fit of the teeth, the risk of jamming increases, especially when changing the direction of rotation. Therefore, hypoid gears require high precision adjustment and the use of special gear oil. Anti-wear and extreme pressure additives are added to hypoid gear oils.

In front-wheel drive cars, where there is no need to change the direction of the transmitted torque, simple spur gears are used in the final drive. Structurally, the main gear is installed in a common housing with the gearbox. Spur gears are easy to manufacture, inexpensive, and the risk of scuffing is low. Therefore, in most cases, to lubricate them, not special transmission oil is used, but motor oil.

How does the gear ratio of the main pair affect the traction and dynamic characteristics? The higher it is, the faster the acceleration occurs, but the maximum speed is lower. Conversely, as the gear ratio decreases, the car accelerates more slowly but reaches a higher top speed. The gear ratio for a specific car model is selected taking into account the characteristics of the engine, wheel size, and braking system capabilities.

Design and principle of operation

From a technical point of view, the differential is designed quite simply, but at the same time it is able to withstand enormous loads. What's inside this node and how does it work?

By its type, it is a planetary gearbox with all the necessary elements.

1. The final drive gear supplies rotation from the gearbox to the differential.
2. The driven gear is connected to both the main gear and the satellite gears.
3. Satellites are fixed in the “cup” of the driven gear, so that they rotate with it.
4. Axle gears are connected to the satellites and do not contact the rest of the differential elements.

Shown in detail in the video below.

1. The main gear shaft comes from the gearbox, from which rotation is transmitted to the driven gear.
2. The driven gear and the “cup” (carrier) attached to it receive torque.
3. Rotating, the driven gear and cup set the satellite gears in motion.
4. The satellites, in turn, transmit rotation to the axle shafts.
5. With an equal load on the axle shafts (when the car is moving on a straight road with a uniform surface), the satellites do not rotate. Only the driven gear works, in the cup of which the satellites are fixed, and they rotate together with it, without rotating around their axis. Thus, the torque is distributed equally on the axle shaft, 50:50.
6. When the car turns and one of the wheels should slow down and the other should speed up, the satellites begin to move. Due to the bevel gear, they rotate, slowing down one axle shaft and accelerating the second. In other words, they redistribute the torque in the required proportion, up to 0:100 without loss of force.
7. When one wheel slips, the locking mechanism is activated, without which the wheel that rotates faster would lose all the torque. Without blocking, the car stops when at least one wheel hits a slippery surface.

When moving in a straight line

When a car moves in a straight line on a smooth surface with a hard, dry surface, both axle shafts rotate at the same angular velocity. The side gears are at rest relative to each other, the entire differential is very similar to a monolithic structure.

The satellites, being connected through their teeth to both semi-axial gears, do not rotate relative to their axes. The moment is distributed equally between the axles if the differential is symmetrical and free, that is, without locking. However, with blocking in this ideal case it will be the same.

When turning

When turning, and this is the normal operating mode of the differential, since ideal straight lines do not exist in nature, one of the wheels will always rotate faster. The satellites will begin to move relative to their axes, but the connection between the semi-axial gears and the body will not be lost. That is, the moment will continue to be transmitted from the body to the wheels, and everything in the same 50/50 ratio.

This is very interesting to consider from a power point of view. The torque is the same, but the speed of the wheel outer from the turn is greater, that is, proportionally more power is transferred to it.

And this is not surprising, since the higher the speed, the higher the losses, which are compensated by the addition of power. In this case, there will not be the slightest interference with the rotation of the wheels at different speeds, unlike a rigid connection.

When slipping

Things are much less pleasant when one of the wheels hits a relatively slippery section of the road and slips during acceleration. There is no grip on the road, which means the moment of resistance of the coating drops sharply. But this moment is always equal to the traction moment, this is the law of physics. This means the traction torque will drop.

A free symmetrical differential divides the power in half between the wheels. It's always 50/50. That is, when the torque on one drops to zero, on the second it will reset automatically. The car will begin to lose speed, and if we are talking about starting off on ice or liquid mud, then it will simply remain there, unable to get out of the ambush.

This is the main disadvantage of a free differential. It can only transmit the force that a wheel in worse conditions can handle. Even if the second one is on dry, clean asphalt, the car will not go anywhere. All the energy will be spent on the rapid and useless rotation of the slipping wheel.

Self-installation of the mechanism

As mentioned earlier, it is necessary to install a differential on a Niva yourself, taking into account the class of the road, the type of vehicle and the degree of its wear. To work you will need to drive onto an overpass. This is easy to find in a garage cooperative. Before starting work, you must make sure that the diagram with the technical description is in front of your eyes (IMAGE 1).

From the theoretical part you need to move smoothly to the practical. To work you will need a standard set of tools. Using wrenches and a screwdriver, the self-locking differential is unscrewed. After this, a visual inspection of the area is carried out. The presence of minimal chips or signs of physical wear on the front part or rear element requires preliminary technical replacement.

Once everything is ready, the surface is treated with anti-corrosion treatment. A new self-block that has passed preliminary testing is installed. After installation, you need to check how successfully partial or complete blocking is activated.

A properly organized locking system is used to increase the transmission of torque to the front or rear wheels.

This helps when slipping and for off-road driving. Regular maintenance will ensure safe operation of the vehicle and reduce the likelihood of skidding. You can eliminate any malfunctions yourself or by contacting a service station.

7. Distribution of torques in the transfer case

The question comes up quite often. Misunderstanding arises due to the fact that completely different physical phenomena are confused: force (moment) and motion (rotation).

First, a few starting points.

1. An unlocked symmetrical differential distributes the torque coming from the input shaft to the output shafts exactly equally: 50/50. This follows from the fact that the gear ratios from the input shaft to the output shaft are the same. In this case, the output shafts can rotate at different speeds, but the average speed (half the sum of the speeds) is equal to the speed of the input shaft divided by the gear ratio.

2. A locked differential ceases to be a differential. The movement (rotation) of the input shaft is transmitted equally to the output shafts. The speeds of the output shafts are equal to each other, and their sum is equal to the speed of the input shaft divided by the gear ratio.

3. If the total torque applied to the shaft (wheel) is not zero, the rotation will be accelerated or decelerated. This is Newton's second law. If the shaft or wheel rotates uniformly, the total torque acting on it is exactly zero. The absence of movement is also uniform rotation, but with zero speed.

There are three symmetrical differentials in the field. When they are all unlocked, each wheel receives 25% of the torque transmitted through the transmission from the engine. And the rotation generated by the engine is also transmitted to all four wheels, but not necessarily equally. For example, when turning, the rear wheels travel a shorter distance (smaller radius) than the front wheels, but all four wheels pull equally.

Let's consider a situation where one wheel is slipping, the rest are standing. All engine rotation is transmitted to the slipping wheel. Strange as it may seem at first glance, the slipping wheel accounts for 25% of the torque, exactly the same as the rest. But this moment is small: it is equal to the moment of friction (only in the transmission, if the wheel is completely suspended). This means that the moment on the other wheels is also very small, it cannot move the car. The car is stationary, and the suspended wheel rotates at a speed that is four times higher than it would be during normal movement at speed at the same engine speed and with the same gears in the gearbox and transfer case.

Now let's turn on the center differential lock. The rotation speeds of the cardan shafts are forcibly equalized. The total speed of the front wheels should be equal to the total speed of the rear wheels.

A few words about the Chevrolet Niva transfer case

I think it’s time to talk about the transfer case of the Chevy Niva, because those who just bought this car, at the very beginning of use, do not really know how to use the transfer case, what the rules are, and in general, when to lower the gear and when to lock it. Let's figure it out now. It’s a pity, of course, that I didn’t record a video on today’s drive along a fairly washed-out road. Well, never mind, I’ll record it and show it clearly on video. For now, in words.

In general, the transfer case switches to a lower gear, as well as to lock, and it is possible and even necessary to do this at the same time. It’s convenient on the Shevik - this is done with one lever.

Turn it down - right up. Add lock - Pull the lever all the way to the left. Look at the switch handle, it's written there. Letter designation - L(low) - low, N - neutral, H(high) - high, that is, normal.

It looks something like this - we are driving across the field in normal second/third gear. Suddenly there is a terrible puddle ahead. We stop and turn down the car.

You may ask - how long does it take to turn on the blocking and then turn it off? There is another nuance here - very often, many owners of the Chevrolet Niva have a problem with the blocking - it does not turn off. It just jams and that’s it, you have to drive on the highway with the blockage. This, you understand, is very harmful for the machine and in such cases you must turn it off.

In bright sunny weather it is sometimes difficult to see. Be careful. Well, about turning off the center wheel - I managed to turn it off just when reversing. Needless to say, now I turn it on only in the most dire cases. In the rest of the others, lower gears are quite enough for me.

Just today I went to the lake to check if the ice had melted. The road was washed out, the snow had already melted and turned into liquid mud, and it’s not safe to drive through such mud on my AT tires. It feels like it’s being dragged in all directions, but the most important thing is that I’m driving, I don’t get stuck, and sometimes the ruts were almost to the very bottom; when you shuffle, it always becomes unpleasant)) After some short drives, the car looked “military-like” - all covered in mud , went to the city - people look around))

And here’s another observation of mine: it’s better to drive through mud slowly but surely. This applies to lower gears - if the mud is serious, then I always drive in first, pushing hard, trying to feel the wheels spinning in the mud. If you accelerate a little, you can immediately “burrow”, this is the case when there is no hard covering under the liquid mud.

When you turn on the second lower gear, the car accelerates, but if you get into a mud hole, there is a risk that the engine will “choke” (it is very difficult to spin the wheels in the second gear when stuck) and you will stall. Needless to say, stalling in a deep puddle can be dangerous. Therefore, if you decide to overcome a puddle or muddy area with acceleration (very often this makes sense), then be prepared in the middle, if you suddenly start to fall through, immediately switch from 2 to 1 low, so as not to stall.

All this knowledge - when to go in first and when in second, when to turn on the lock and when not necessary - all this comes with experience. You’ll ride in the mud and you’ll already begin to understand that it’s better to take the puddle over there with acceleration without locking, and that clay hill with potholes - only at 1 lower gear and with the locking on. Think with your head first, and don’t rely on the car to pull it out. The Chevrolet Niva is an excellent car, if you don’t be stupid.

I remember when we were making our way to an abandoned village, we got to one really dangerous place, and there was a UAZ standing there and didn’t dare to drive through. We scouted around and decided that we would pass. And we drove by, leisurely, pushing hard, without particularly accelerating.

Therefore, one more rule (which I always adhere to) - if the place is dangerous, there is a risk of getting stuck, then get out of the car, poke it with a branch, find out the depth of the puddle, rut, feel for a solid place where you can drive. This is the job of the navigator, so let your partner get out of the car and don’t be lazy. Spend 5 minutes on reconnaissance so that you don’t have to spend several hours later getting out of an ambush.

My review of Dak and Racing

It just so happened that I had to use the two mentioned types of self-blocks. Their price at the time of purchase was almost the same - ten thousand, the installation is also the same, but the result is completely different.

If the DAK failed after about six months, and not in intensive use, but when driving on ordinary forest roads, then the Togliatti one (val racing) is still working.

Maybe I was just unlucky, but I have repeatedly come across reports that there are problems with the quality of the metal in the production of DAKs. So think for yourself.

Is it necessary?

There are a huge number of opinions about whether a self-block is needed at all, and the most polar ones - from “why is it needed” to “is absolutely necessary.” As always, the choice is a personal matter and everyone must make it themselves.

It seems to me that everything depends on how and where you move in your car. If you go to the country or mostly on asphalt, then you definitely don’t need a self-block.

The situation is approximately the same if your hobby is off-roading and you are engaged in conquering impassable roads. Here, such “half measures” as self-locking will not work and here you need a full manual differential lock.

However, if your task is to overcome not too severe off-road conditions, driving along a wet, broken forest road, i.e. normal conditions without extreme conditions, then self-block can be a good helper in such conditions.

Maybe it seems to me, maybe I have the self-locking set up this way, maybe that’s not the issue, but often when the car starts to “slip”, a jerk in the opposite direction suddenly appears. It’s as if the car first went to where the wheel was blocked, and then it gained momentum again, and the car jerks in the opposite direction.

A self-locking differential for the Niva is a good addition that, if used correctly, can significantly improve its off-road properties.

DIY self-block installation instructions

To install a self-locking differential on a Niva, it is not necessary to contact a car service center. It is quite possible to do this with your own hands, provided that the person has a good understanding of the structure of the car. The type of differential and its installation location are not particularly important.

First you need to decide on the place where the work will be done; it should be spacious enough. Using several jacks, you will need to lift the Niva, dismantle the wheels, then drain the engine oil from the gearbox housing into some container and remove the drive axle drive. To do this, just use a spanner to unscrew all the nuts securing the front cover to the gearbox housing, remove the cover and gasket.

Now it is necessary to reliably and efficiently carry out the operation of dismantling the axle shafts, which is very difficult to do without a special puller. The metal is clamped on rotary slots, which requires a lot of effort, which not every person has enough. Dismantling the axle shafts is carried out as follows:

• Unscrew all the bolt nuts on the axle bearing mounting plate.
• The brake mechanism is fixed. This can be done using bolts or wire. If the mechanism is not secured, the brake lines may come off.
• The axle shaft itself is removed. With sufficient skill, this can be done by hand, but it is better with the help of a puller.

Then you need to change the bearings. This will require a hydraulic press. It will help ensure that the holder fits onto the shaft, and with fairly high accuracy. To replace you need:

• Unscrew the hub bearing nut and remove the bushing. Unscrew the nut securing the lever to the steering knuckle.
• Remove the locking plate and unscrew the lever from the steering knuckle.
• Having disconnected all the fasteners, separate the knuckle and the hub with the brake disc. Remove the bearing by first holding the steering knuckle in a vice. During assembly, the bearing is put on using a press.

Read also: Tightening torques for threaded connections of the KAMAZ 740 engine After the clearances in the main gear are adjusted using special washers with variable thickness, you can begin assembling the unit. Adjusting the gaps is quite difficult, and you will need special equipment, but to ensure accuracy you can use a steelyard. To work with it, wind one end of a 1 m long cord around the flange and secure the other end to the scales. By pulling the device in the winding, you will need to record the turning moment.

To ensure proper operation of the gearbox, the parts are usually sealed before the halves are assembled. In its absence, malfunctions may occur during operation, as well as failure of certain spare parts. After applying the sealant, you need to wait a while for it to harden. Then new oil should be poured into the gear housing. All sealing joints that were damaged during dismantling, as well as those that show signs of oil leakage, must be completely replaced with new ones. Now you can start assembling all the mechanisms in reverse order.

The feasibility of such an action as differential locking on a Niva depends on why the driver needs it. If you need to move through difficult areas, you will need it. If a car enthusiast intends to drive on a normal asphalt road, then installing a self-locking differential on the Niva is hardly worth it. Which self-block to choose and where to place it depends on the driver’s preferences.

• January 11, 2019
• Cars
• Eugene

The self-locking differential on the Niva, like any other analogue, is a device that serves to transform torque from the vehicle engine to the wheels using transmission elements. The factory free-configuration self-block cannot affect the other when one wheel slips. Blocking the part in question helps to obtain the necessary difference off-road. It increases the torsional moment on one of the wheels, which better grips the road. An alternative would be a forced blocking method. Let's try to figure out how effective the self-locking differential on the Niva is, as well as the method of installing this unit.

Removing axle shafts and bearings

To install a self-locking differential on a Niva 4x4, you need to carefully and efficiently remove the axle shafts. A special puller will be required. Otherwise, this is problematic, since the metal sticks to the slots. Stages of dismantling axle shafts and bearings:

1. Unscrew all the bolt nuts on the plate element for fixing the axle bearing.
2. The brake block is secured with bolts or fittings of a suitable diameter. If you ignore this procedure, the brake lines will come off.
3. The axle shaft is removed directly using a special device.
4. To dismantle the bearings, you will need a hydraulic press, which will make it easier to fit the race onto the shaft with high precision.
5. Unscrew the wheel bearing nut and remove the bushing.
6. Unscrew the fastening nut securing the lever with the rotary cam.
7. Remove the stupor plate and remove the lever.
8. Disconnect all fasteners, disconnect the hub with the brake disc and the knuckle. Dismantle the bearing, having previously fixed the rotating element in a vice. The bearing is also installed by pressing.

Removing the Niva transfer case

To repair the transfer case on a VAZ 21213 (21214), the unit must first be removed. We carry out removal in the following order:

• in the cabin we dismantle the plastic lining of the gearbox and gearbox levers;
• unscrew the knobs of the transfer case shift levers, remove the casing under them;
• disconnect the speedometer cable, for RK 21214 you will need to additionally disconnect the speed sensor;
• we unscrew the bolts with nuts securing the elastic coupling of the front and rear propeller shafts; in order to remove the bolts, the cardan shafts must be turned - they are removed one at a time in one specific position of the shaft;
• We install a jack (or other support) under the transfer case and mark the places where the side supports of the RC were attached. This is done in order to minimize the alignment of the transfer case during installation;
• unscrew the 4 nuts securing the gearbox to the gearbox;
• unscrew the 4 fastenings of the RC supports to the car body;
• Now all that remains is to dismantle the transfer case.