How does a Niva transmission work? Permanent all-wheel drive "Niva" - How it works and rules of use What is permanent all-wheel drive

The VAZ 2121, in other words, “Niva”, entered mass production in the 70s of the last century. This car belongs to the class passenger cars off-road. In the history of the domestic automobile industry, Niva became the first car to use four-wheel drive. Let's take a closer look at the transmission device. This should be done in order to understand why, given its almost 40-year history, the Niva transmission differs from many other similar vehicles equipped with all-wheel drive and the ability to shift in the classical way or using a viscous coupling.

The transmission in the Niva family (2121, 2131) is designed in such a way that all-wheel drive is supplied to 4 wheels. Also characteristic is the presence of a center differential. The transmission includes a gearbox, a transfer mechanism, a pair of cardan shafts, and both axles. Characteristic difference Model 2131 is an extended body. Otherwise, the main similarities with the first model can be seen throughout. Torque is transmitted from the engine through the gearbox to the transfer case, and it, in turn, transmits torque to the axles.

Then it goes through the cardan shafts to the gearboxes. Front gearbox via differential and equal joints angular velocities transmits torque to the wheels. Likewise for the rear, also protruding, driving wheels. It is precisely because the torque is distributed to 4 wheels simultaneously that the drive is called full drive. The designation is as follows – 4WD. Another domestic car, designed on a similar principle to the Niva - UAZ.

This mechanism is a kind of distributor of traction forces coming from the motor to the wheels. Important feature is that the latter have the ability to rotate at different speeds. The importance of having a differential mechanism is due to the fact that during turning maneuvers, the wheel located inside makes fewer revolutions when compared with the number of turns of the outer wheel.

In the absence of a differential mechanism, this would cause detrimental consequences, such as wear and damage, because the result would be: one wheel would be in axle box when turning, and the other would simply rub against the road surface. The design features of the Niva transmission provide for the presence of 3 differentials. They are located in each of the bridges and in the transfer mechanism.

When the car is moving along smooth road and straight-line differentials divide the traction force equally between all 4 wheels. If there is insufficient adhesion of the wheels to the surface or slipping occurs, the differentials will redistribute the load on the slipping and sliding wheel so that the first receives more force, and the second, accordingly, less.

We have already mentioned UAZ. Despite many similarities, it should be understood that the VAZ’s all-wheel drive is made in the “pat-time” style. This means that when connected, the axes are firmly connected to each other, and rotation occurs at the same speeds. This device imposes some restrictions on the use of all-wheel drive - it can only be used in cases where road conditions allow slipping. In cases with hard asphalt roads and highways, it is recommended to switch the car to single-drive mode.

Differential locking

Sometimes you can come across a misconception about why a small handle is needed next to the shift lever on a Niva. Some car owners believe that it is needed to connect front-wheel drive. However front-wheel drive at of this car permanently connected. As is the rear one. Cars of the Niva family have permanent all-wheel drive. The handle actually serves to switch the operating modes of the differential of the transfer mechanism.

In the “forward” position, the differential operates as usual, but if you move it back, the differential is locked, and the forces from the motor are applied to the differentials of the axles, which makes the drive more rigid. It is worth noting that there are also special types locks for front and rear axles.

In theory, when used in conditions where the car is stuck, it will be able to overcome the obstacle if there is sufficient traction on at least one wheel. In this case, it is better to lock the differential before overcoming an obstacle, but never after entering an area that is difficult to overcome. This application of locking will avoid wear and damage to the transmission.

A series of downshifts

You can often encounter the following type of misconception: switching the rear handle can increase the power characteristics of the motor. But this is not true. It serves to change the gear ratio between the engine and the wheels. By increasing it, the traction forces on the wheels will increase. There is also a reduction gear in the dispensing mechanism.

Its operation can be controlled using the rear handle. When we shift the lever back, we will have a gear ratio of 2.135 - this is a low gear. It is recommended to downshift such a gear only when the car is stationary and the clutch is depressed. Despite the fact that the manual does not contain such a restriction, novice and inexperienced Niva drivers are not recommended to switch while driving, since the Niva transfer mechanism is not equipped with a synchronizer.

To make driving your car comfortable, read some important points:

1. The usual, standard arrangement of the front and rear handles is forward and backward, respectively. Movement in this mode can and should be carried out in areas characterized by even and smooth surfaces.
2. Locking the differential by switching the front handle to the rear position is best on roads characterized by increased slipperiness. This measure will give Niva stability. It is worth understanding that after overcoming the problem area, the handle will need to be returned to its original position.
3. As noted earlier, downshift should be activated before a potential obstacle, but not while the car is already stuck.
4. It is worth understanding that activating the lock when the vehicle is stationary is sometimes impossible, even if the clutch is depressed. This may be caused by the clutch teeth hitting the gear teeth. In this case, you can try to activate the lock by starting to drive slowly and make a slight turn. If problems arise with disabling the lock, it is recommended to perform the same procedure with the clutch depressed and the steering wheel slightly rocked.

When creating the first SUVs, almost no manufacturer thought about such a component as comfort. And why would this be, if the main consumers of such machines then were the armed forces. But over time, many people thought about developing a car that combines the high cross-country ability of an SUV and the comfort of a family sedan. It is gratifying that our country was one of the pioneers in this

The history of the creation of the domestic SUV that is still produced today began in the summer of 1970. Chairman of the Council of Ministers Alexey Nikolaevich Kosygin paid a visit to the newly launched Volzhsky Automobile Plant. Then the question arose about the possibility of creating comfortable car with a 4x4 wheel arrangement, designed for workers Agriculture. At that time, one phrase from a high official was enough to start work on an all-wheel drive vehicle. And not only at VAZ. Many presented their projects automobile factories THE USSR. It cannot be said that the birth of a compact all-terrain vehicle was simple. Only seven years after Kosygin’s visit, on April 5, 1977, serial production of the VAZ2121 began. But the result was impressive. Suffice it to say that the design of the car turned out to be so innovative for that time that many of the ideas used on it subsequently migrated to models from the world's leading manufacturers, and the Niva itself still remains the most popular SUV in Russia.

Body and interior

Unlike the vast majority of all-terrain vehicles thirty years ago, the Niva does not have a supporting frame. Its role is performed directly by the power structure of the body. Like all products from domestic manufacturers, its corrosion resistance leaves much to be desired. Therefore, thrifty owners perceive annual anti-corrosion treatment of their car as inevitable, akin to trips to scheduled maintenance.

However, even if this rule is followed, few people succeed in delaying the formation of through holes in the thresholds for a long time. In addition, it is necessary to carefully monitor the condition of the ventilation holes in the lower edges of the doors and thresholds (if they are clogged with dirt or anticorrosive compounds, then moisture begins to accumulate in the internal cavities of these parts, which significantly accelerates the corrosion process). When a car is frequently exposed to domestic anti-icing reagents, the side members in the front part of the car rust very quickly, and traces of corrosion in the places where body parts are welded may appear already in the first year of operation. But perhaps the most vulnerable spot- part of the floor in the area where the transfer case is mounted. If not properly treated, it simply rots. Vibrations from the transmission contribute no less to the destruction of this area. Therefore, many experienced “field workers”, who often leave hard surfaces, reinforce this place with an additional sheet of iron. The pre-restyling version of the Niva with the factory index 2121 had a short trunk door: its lower edge is one of the fastest rotting places in the car. On the updated model 21213, the cargo compartment door opening was lowered to the rear bumper, and the corrosion resistance of the third door was slightly increased. By the way, if on the VAZ-2121 it can only be opened from the outside, then on the modernized version it can be opened exclusively from the interior using a handle located at the rear left passenger’s knee.

Interesting feature in the body structure for those who often use the Niva as a tow truck. If the front towing eye is screwed directly to the side member and can withstand heavy loads, the rear one is attached to the joint of three body parts, so there are cases when, under heavy loads, it was torn out along with part of the elements of the body itself

Engine

The first production VAZ-2121 was equipped with a 1.6-liter carburetor engine, inherited from the VAZ-2106. The engine had an overhead camshaft drive via a multi-row roller chain. Generally power unit It is considered quite reliable and unpretentious. A little later, for countries where the tax depends on engine size, a version with a 1.3-liter engine was prepared. In our country, such specimens are practically never found. After modernization in 1994, the car, which received the index 21213, began to be equipped with a 1.7-liter carburetor engine with contactless ignition system. Compared to its predecessor’s unit, it had noticeably better low-end traction, but was more prone to detonation when consuming low-quality fuel. The VAZ-2131 was equipped with 1.8 liter engines.

On all carburetor versions, the cooling system used a radiator fan with a mechanical drive from crankshaft. A significant disadvantage of this scheme is the insufficient air flow to the radiator when the engine is running at idle speed. Therefore, in traffic jams, especially in hot weather, working temperature rises very quickly above the critical value. The result is banal overheating, which, if not prevented in time, can lead to serious engine repairs. This problem was eliminated only with the advent of the VAZ-21214, which installed two electric fans. Frequent problems Overheating is not observed in these cars. In addition, the engine of this version received an injection system instead of a carburetor. Both central GM and multi-point Bosch were used. The gas distribution system was also slightly reworked, using hydraulic lash compensators in the valve drive. On the one hand, this innovation helped to get rid of the frequent procedure for adjusting them, and on the other, the engine became more demanding on the quality of the oil.

Expert opinion

The most common engine malfunctions on the Niva are: the timing chain tensioners and dampers fail, after major repairs the fourth cylinder partition becomes thinner, and the engine begins to overheat. On machines 2121 and 21213, a mechanically driven fan was installed, so the engine often overheats at idle speed.

Regarding the transmission: fifth gear often “flies out”, since the load on the gearbox designed for the VAZ-2106 is much higher here. The clutch usually withstands 40–50 thousand km, but when doing off-road work it can be burned out in one day. The elastic shaft coupling wears out over time, resulting in significantly increased vibrations. Crosses need regular maintenance.

The ball joints in the front suspension also serve 40–50 thousand. The upper right rear silent block, located next to exhaust system, overheats and fails faster than others. Sometimes the front support axle bends lower arm, it has to be strengthened. The wear of steering rods is influenced by driving style - for “racers” they fail earlier.

Transmission

The highlight of the car is permanent all-wheel drive. From the very first Niva to this day, the scheme has not changed. A symmetrical free differential is used as a mechanism that distributes torque between the axles. To increase cross-country ability, it has the ability to force lock. In addition, as befits a serious SUV, the transfer case has a reduction range.

Torque from the transfer case to the drive axles is transmitted through shafts that have two universal joints. The main disadvantage of the Niva transmission is increased vibrations. If on a well-adjusted and serviceable car they are almost not felt, then with the slightest imbalance in one of the elements responsible for transmitting torque, the comfort in the cabin noticeably deteriorates. There are plenty of reasons for the appearance of vibrations - a soured crosspiece in the cardan, a biting CV joint in the shaft, broken spline joints, as well as a misalignment of the transfer case. Sometimes, during long-term operation with such a malfunction, the eyes on the housing of this unit may burst. True, due to the fact that they are not cast together with the body, replacing them is not particularly difficult.

Due to the unification of the car's design with the VAZ passenger cars produced at that time, the housing of the original transfer case is spaced with the gearbox housing, borrowed from the classic Zhiguli. Until 1994, an elastic compensating clutch and a cardan joint were used as an intermediate shaft between the transfer case and the gearbox. After 1994, the output shaft of the gearbox and the input shaft of the transfer case began to be connected by a drive shaft, in which the cross was replaced with a CV joint. Thanks to this solution, it was possible to slightly reduce vibrations. By the way, recently many owners began to use a shaft from Chevrolet Niva with a more effective torsional vibration damper.

On many copies that have not been used outside the asphalt, the transfer case control mechanism may become sour. Since 1999, gears with fine-module teeth began to be used, as a result of which it was possible to significantly reduce the noise from the operation of the transmission. Starting with model 21213, they began to install a five-speed manual box gears instead of a four-speed. By the way, if the “four-stage” was considered an almost eternal unit, then problems arose with the addition of another stage. Due to oil starvation of the fifth gear gear block, their teeth crumble over time, and the housing in the place where this gear operates may crack. Sometimes this happens after only 30 thousand km. Repairs will cost about 4,000 rubles.

The constant velocity joints in the front wheel drive are quite reliable. However, with frequent off-road forays, their anthers quickly wear out and tear. Therefore, they need to be closely monitored, otherwise breakdown is inevitable.

The rear axle is a continuous beam, which usually does not cause any special problems. By the way, if you still have to repair it, you must remember that the parts of this unit on modern and pre-restyling versions are not interchangeable.

Chassis

Good handling on hard surfaces and decent ride smoothness are ensured by independent front and dependent rear spring suspensions. Weakness in the front - ball joints, which sometimes do not last even 40 thousand km. The springs practically do not sag, maintaining ground clearance unchanged for almost the entire life of the car. With careful operation, there are no problems with shock absorbers, which can sometimes last more than 100 thousand km. The bipods of the steering gear and the pendulum arm of the worm steering mechanism of cars produced before 1994 differ from those installed later. At the same time, the effort on the steering wheel of the latter is noticeably less, but the turning circle is larger. When modernizing the pendulum arms, plastic bushings were replaced with plain bearings, although the former are considered more reliable. The steering shaft has also changed: on the VAZ-21213, instead of a solid one, they began to use an injury-proof one, consisting of several parts. The bearings in the hubs of both the front and rear wheels do not cause any particular problems, but periodic adjustment of the clearances by tightening the wheel nuts is required.

Brake system

Regardless of the year of manufacture, the car was equipped with front disc and rear drum brakes. The system includes one circuit acting on the front wheels, the second - on all wheels. Front brake pads Most often they need to be replaced after 20–30 thousand km, and the rear ones - after 60–70 thousand km. When replacing the front ones, it is recommended to clean and lubricate the caliper guides, as they can become sour over time. Brakes The rear wheels of cars from the first years of production need constant clearance adjustment. Cars produced in 1994 do not need this operation, since the working cylinders from the VAZ-2101 were replaced with those used on the VAZ-2105 model. Then they replaced vacuum booster to a more powerful one from the VAZ-2108. Replacement brake fluid is carried out every 20–30 thousand km or once every two years, whichever comes first.

And other diseases...

The traditional disease of the Niva is the same as that of all classic Zhigulis - frequent leaks of the cabin heater valve. A car can be cured of it only by replacing the factory product with ceramics, which is considered more reliable and durable.

Due to the rather primitive circuit of electrical equipment serious problems practically never happens to him. And the biggest troubles in electrical diagram occur due to oxidized contacts due to poor wiring.

All fuses grouped in two blocks located on the left under the instrument panel. It is very important that due to the simplicity of the design, transmitting and receiving electricity from another vehicle does not pose any problems.

In conclusion, I would like to say that, despite a lot of shortcomings (the main ones, by the way, are far from being a design miscalculation), the Niva has been on the assembly line for four decades and, apparently, is not going to retire in the near future. And who else can offer similar car at a very affordable price?

As for congenital and acquired diseases, in our native country they have long ago and quite successfully learned to deal with them even in the most mediocre car service center.

Basic specifications"Niva"

Approximate prices for spare parts*, rub.

* For modification with a 3-door body (after restyling in 1994)

Test Drive

What is permanent all-wheel drive?

And then why is there a lever in the field? differential lock"? The answer is for driving on really bad roads, as well as in the complete absence of them. After all, the presence of three differentials (two axles and a center differential) means that it is enough to lose traction on one wheel (dirt, ice, hanging in the air) and it will happen immediately will begin to rotate at quadruple speed and all other wheels will remain stationary (although they may have good grip.) A locked center differential no longer transmits equal moments, but equal speeds - thus, two wheels will always transmit torque, one on each axle. And the car will stop only if they both lose traction - for example, when hanging diagonally (two wheels diagonally on hills and the remaining two hanging in the air) or dumping one side into some ditch or snow.Further improvement in cross-country ability is possible by also locking the axle differentials, but unfortunately for the Niva there is no such serial version, only a variety of amateur modifications (up to the point of welding tightly one of the differentials - then the car completely loses the ability to drive normally on the roads).

Niva is a tank! But light and shallow-floating

Namely, the Niva is still a compromise between road car and an SUV. Of course, you can ride it to Everest and storm the expanses of the Siberian taiga - but it’s better not to do that. Take pity on your equipment and it will live much longer. This is not a military Ural, you can’t load 10 tons on it and jump from a 5-meter cliff - the suspension is still almost like a classic Lada, albeit reinforced. You shouldn’t dive into a ford after a T-80 tank either, the factory depth of the ford is only 60 cm (and it can be achieved without special training only when moving extremely slowly, otherwise it will splash and stall, and you can turn off the fan and burn the electrics). And in general, you shouldn’t assume that now you can handle everything and you’ll go everywhere - no, with this approach you’ll just go much further and deeper than, for example, the same classic.

But on the roads, the Niva drives quite well on roads in a condition that is quite below average. A grader and a country road, a muddy collective farm track or a river bank - these are the places where you can drive calmly in a field, at a speed determined solely by the desires and skills of the driver, and the car will not let you down. You will not fly away in a turn due to the drift of the only steered axle, which is also the drive axle, and you will not feel that you are simply being carried sideways like on a rear-wheel drive. Even compared to a standard 4*4, driving in a field in such conditions is much better - you can take turns by rolling in rather than sliding with all four wheels. You will not drown in a puddle 10 cm deep and a hole of the same size will not require your head to go through the ceiling.

Transfer case and low gear

And this is a handout. Transfer case if official. A device that makes two from one shaft coming out of the box (the most common one, practically no different from 2107) - for both axles.

One of the levers controls downshift. In fact, this is an additional gearbox with a ratio of about 1:2, connected after the box. That is, where you had 4th (direct) gear, you get something like 2nd, where 2nd is 1st, and where 1st is something even lower, even slower, but with twice the effort. It is used for two purposes - firstly, when there is not enough engine torque in the 1st gear of the upper row (1c) - off-road or when towing a heavy trailer (a 1n Niva can easily move a trolleybus and pull it along a flat surface - and This, by the way, is 8 tons - although, of course, without much agility). And the second goal is to reduce the speed below 1st gear in conditions when there is enough torque, but there is no control speed. For example, when maneuvering (driving into a narrow place or parking lot), driving in a very sluggish traffic jam (where everyone is just pulling the clutch - the engine does not pull below 1000 rpm and even stalls, and there is no speed corresponding to these rpm in the traffic jam). It is very convenient then to turn on the lower row and move calmly without burning out the clutch and without jumping forward at each start-stop.

You can turn off the bottom row without stopping the car. Like on a regular gearbox, only unsynchronized (you may have heard “experienced stories” about all sorts of double squeezes and "gear grinding"? This all happened back then when the main boxes were unsynchronized). That is, with the selection of speed on the shafts and the careful and fairly slow engagement of the gears. The factory prohibits turning on the bottom row this way only after stopping the car. But practically when moving with very low speed(up to 5 km/h - walking speed) this works quite well if you practice a little, and without the scary grunts in the box. Just under no circumstances try to press the gear - if it crunches and does not fit, then applying force can only collapse the transfer case, followed by expensive repairs.

The second lever is the control of the above center differential. Forward - normal mode, backward - locked, for heavy road conditions. Attention - turning on and especially turning off this blocking is not always possible. It may simply “not go” - if the shafts are not aligned in the right position or “bite” if force is applied to this blocking (turning on the road with noticeable wheel grip). Drive forward (or maybe backward) a little and the lever will move to the desired position without much difficulty. Again, do not try to press the switch on - if it is already crunching, it means the shafts are turning relative to each other and switching on is impossible. Stop or go to rectilinear movement(when there is no difference in paths between bridges). When the lock is on, a yellow light on the instrument panel lights up - this is a reminder that you should drive in this mode. good roads it is forbidden.

I'm a cool wide jeeper - I turned on the second axle and drove!

These are the ones we treat: Once again, You can't drive a field with a locked differential on good roads. The transfer case, gearboxes and cardans will fall apart, the tires will quickly eat up and there is a noticeable risk of going outside when turning (Spite comment: unfortunately modern medicine and the prices of car services are not yet able to completely overcome insanity. There are many individuals in nature who have ruined more than one car, but have never understood the essence of the phenomena. For all the discussions about the cr. torque, differentials or transfer case, they have a reasonable, parity answer: “What the hell, this is a jeep, fuck!”)

The only mode when it is justified to turn on the lock when driving on more or less decent roads is on a grader. When there are no turns, there is speed (the car is quite capable of driving 100 or more on a fairly average collective farm grader - just be careful with the brakes, they move away from the side vibration and require one or two presses to move the pads into place) and every cobblestone, bump or pit strives turn the car around a vertical axis (along the heading in the sense). The Niva is a short-wheelbase car and therefore side impacts have a very significant impact on the exchange rate. Enabling the lock allows you to somewhat reduce the effect (at the cost of naturally reducing the service life and increasing gasoline consumption - slipping when turning and small deviations will not disappear).

So when to turn on what?

The basic rule is to turn it on first and then go for the assault. If you can see a boundless swamp ahead with the traces of the Kirovets tractor stretching into the abyss, then you need to stop, turn on 1H and lock, look around and take a detour. The Niva practically cannot overcome such obstacles, but it lands thoroughly in them, so pushing it out with the help of the crew is unrealistic.

If there is a dry but uneven and generally dubious road (country road) ahead, then it is usually enough to turn on the bottom row. And move forward according to the situation - where exactly at 2n (this is approximately the same as 1v) and can even be up to 5v (this is something between 2v and 3v - you can accelerate up to 80 kilometers), where there is a hillock - reducing speed and moving down to 1n.

If there is a slippery and very doubtful area ahead (mud, snow, puddle, ford), then stop and engage the lock and the lower row. Then it may be too late - if you wait to turn it on until the moment when the car starts to stop for natural reasons (not enough torque or the wheels slip), then there is a noticeable chance of not moving again.

What's it like in the city?

Fine. I sit high up and look far away, I’m not afraid of hatches with tram rails and the snowdrift at the entrance to the yard is not a terrible and terrible insurmountable obstacle. There are just not enough doors - it’s not very convenient to carry passengers in the field, there are problems with entry and exit (as with all two-door cars). In terms of dynamics in urban conditions (speed 40-90 km) it is quite at the level of the rest of the traffic, in terms of ease of control, etc. - the Lada is like a Lada. But it’s durable (of course you shouldn’t go head-on, but small collisions often don’t even leave traces - with such bumpers), load-carrying (there’s absolutely no problem taking half a ton of cargo, as long as it fits inside), short (essential when parking). The turning radius is only larger, but what can you do, this is the price for front-wheel drive with huge 16" wheels.

Will it bring...?

You'll be lucky. As luck would have it, the Niva’s load-carrying capacity and cargo capacity are quite impressive. Stiff, energy-intensive suspension springs are capable of keeping the car completely away from the travel limiters, even if you load it with passengers according to the principle of “as much as you can fit” or cargo “as much as you can fit.” Well, unless of course you load it with bricks, bags of cement or gold bars. She almost doesn’t feel 200 kg of load (and on a classic Lada, the mudguards already rub on the asphalt if you stuff so much into the trunk, and the side members burst).

To transport cargo in the field, the rear seat can be folded. The backrest is forward and then it and the pillow are forward again. Unlike 2121, to completely clean the seat, you need to throw over the hinges of its fastening - this is described in the instructions.

But there is a second option for folding the seat, which is not described in the instructions and is generally little known. It turns out that the rear Niva seat can be folded completely horizontally! To do this, you need to turn it out - pull the loops between the pillow and the backrest forward and upward, thereby placing the pillow vertically upward and the backrest horizontally back. Then push the backrest under the brackets for its fastening behind the rear wheel arches and lower everything down. The result is an almost flat surface front seat(and even the front panel if unfolded passenger seat- you just need to pull out the headrest) to the back door. Two and a half meters - more than in the Volga "barn" (its right seat does not fold out flush with the rear one). And it’s quite high, up to the roof. You can carry something long or spend the night in nature.

Permanent all-wheel drive. Is this good or bad? The Niva transmission is built in such a way that the torque from the engine is transmitted to the gearbox and then to the transfer case in which the cross-axle differential is installed. which divides the torque 50x50 between the front and rear axles. then the torque moves to the front and rear axle differentials of which also divide the torque between the wheels 50x50. Uniform distribution of torque allows the all-wheel drive to operate elastically. In the normal state, when one of the wheels is suspended, torque will be transmitted to the suspended wheel 4 times faster due to two differentials. That is, if the car is stuck and one of the least loaded wheels is hanging out, it doesn’t matter the front or rear, it will rotate 4 times faster than the required speed. If we assume a rotation speed in first gear of 20 km/h, then at the output the wheel will produce all 80. The transfer case has a rigid locking of the center differential, which allows you to synchronously transmit torque to the front and rear axles, that is, enable permanent hard all-wheel drive.

Moreover, if there is a diagonal hanging, then the moment will be transmitted to the front and rear wheels, which have less traction with the soil. Accordingly, due to the differentials, the rotation speed of these wheels will be doubled. The transfer case also has a reduction gear that increases the torque transmitted to the axles and reduces the rotation speed.

Two short levers, the first is closer to the panel to lock the center differential, the second is to engage a lower gear. So that's why I'm writing this. Niva has one property. On a slippery road with the differential not locked, it can unexpectedly turn around and lose control. Moreover, this happens instantly, even experienced driver does not have time to react to such a somersault. Why am I writing about this? There was a time when I worked at Niva and carried mail around the area. I studied her habits inside and out. Of course, it has excellent cross-country ability, even with the differential not locked. When moving and accelerating, the torque is distributed along the floor along the axes. And only hanging one of the wheels can stop the movement. But the Niva has a long-travel suspension and wheels almost always have traction with the ground, so redistribution between the wheels occurs evenly and all-wheel drive works as expected.

The Niva perfectly overcomes mud, sand, and snow drifts. And almost any rough terrain. But this article is not about the all-terrain capabilities of the vehicle, but about the features of control in slippery conditions. Namely, knurled winter road, ice, low grip soil.

I have repeatedly found myself in the situation of a car completely turning around on a slippery road, and if the car starts to turn around, this cannot be changed, it cannot be corrected by steering wheel and increasing the gas. Especially if it happens at sufficient speed. a split second and the car goes backwards to front. The driver doesn't even have time to react. But this is only if the differential is not locked. Although all-wheel drive is always on! This kind of somersault is the norm. And now I want to make a rationale this fact. What is this connected with?

For this, a short excursion and comparison with other drives. And for example, let's take rear-wheel drive. Using the example of classics 2101-2107

Rotation is only possible for rear wheels. In slippery conditions, you have to work the gas pedal very carefully; a small mistake causes slipping and at this moment, when maneuvering or running over one of the wheels, the car can easily turn around. Moreover, the engine located at the front of the machine loads the front axle. The light rear does not load the drive wheels; as a result, the wheels slip due to lack of traction and the load on the drive axle.

But drivers are adapting. Winter tires+ Ballast in the trunk is 50-60 kg and you can move. Skidding with rear-wheel drive occurs both when accelerating and when releasing the gas. But drivers know these habits. Therefore, you can adapt and everyone drives like that.

Front-wheel drive is much preferable to rear-wheel drive on slippery roads. The drive wheels are loaded by the engine + they also pull the car along with them into the turn. The only difference is that when entering a turn, do not let off the gas, otherwise the rear may throw up and the car will turn around.

And so returning to the all-wheel drive Niva. When the center differential is turned off, the torque between the axles is divided in half. But the load on the front and rear axle is different. Pre-loaded with engine box and transfer case. The rear of the car is short; the load on the rear axle is less. Now imagine the situation of driving on a slippery road. The driver is completely confident in himself, all-wheel drive is always on, what to fear. When driving and accelerating everything is fine. The car drives confidently both on slippery roads and on inclines. But then the driver let off the gas and swerved the steering wheel a little in front of the obstacle. The rear wheels, which are already less loaded, transfer part of the load to the front wheels when releasing the gas. The front wheels have good grip and still make friends. By resting, they slow down the movement of the car, but through the center differential they redistribute part of the load to the rear, as a result, the force is directed to the unloaded rear wheels. I repeat, the car is slowed down by the transmission! The engine speed drops and acts as a brake. I’ll continue, through good traction of the front loaded wheels, torque is transmitted back to the transmission; the wheels force the engine to spin while it slows them down. But there is a differential between the axles and it is not locked, which means that part of the energy goes to the rear axle, and what will win is either the engine will spin up or the rear wheels will begin to slide, and as soon as the loss of traction begins, the wheels will first slow down their rotation, then the torque will easily be transferred from the front axle to the rear, and the rear wheels will have a braking effect. While the front wheels will spin without locking, the rear wheels will also spin but at a lower speed due to the error on the front differential. In the end, what does this mean? Complete loss of traction rear axle with the road. It's just a sleigh. Therefore, with any maneuver, the car will instantly turn around and there is nothing to be done about it. The peculiarity of such a transmission. Therefore, on slippery surfaces it is imperative to block the center differential. Then the torque and braking torque are transmitted rigidly to the two axles and the machine has good stability.

VAZ 21213 “Niva” is one of the most successful and significant developments for the Volzhsky Automobile Plant. We can say that Niva is the most significant model in the entire history of the domestic automotive industry. Initially this car characterized as a passenger car with 4x4 all-wheel drive. What secrets does this model hide, what's under the hood and how long has it been around? About all this and more - further in our article.

Production history

Serial production of the VAZ Niva 21213 began in 1977. The most eminent design engineers of the USSR were involved in the development of this SUV. Probably, it was the unity of all the actions of the design bureau workers that made it possible to create a car characterized by high cross-country ability, light weight and low maintenance.

VAZ Niva 21213 is the first car in the history of the domestic automotive industry that was created specifically for off-road driving, traveling to the most inaccessible places, as well as for fishing and hunting trips. All this was facilitated not only by all-wheel drive and a powerful gasoline engine for those times, but also by a practical body layout - folding backseat made it possible to place various household cargo weighing up to several hundred kilograms inside the Niva.

Domestic Range Rover?

What does the domestic Rover have in common with the British Rover? At first glance, absolutely nothing. However, you just have to take a closer look at the technical part, and everything will become clear. The fact is that the Niva used a non-disconnectable drive on all four wheels with a transfer case and a locking center differential. This is exactly what the British Range Rover had in the 70s. Thanks to such equipment, the domestic SUV could easily overcome fords, ravines and other off-road conditions. At that time, the new Soviet jeep had no analogues in terms of cross-country ability and comfort.

About the SUV body

It is worth saying that initially the VAZ Niva 21213 was not all-metal. The first experimental modifications of the SUV in question had an open body, the roof of which was covered with a tarpaulin (a kind of all-terrain convertible). However, only models with a solid metal body, which we now see on the streets, entered mass production.

Equipment and comfort

At first glance, the VAZ Niva 21213 is the Volga analogue of the Ural UAZ 469 model. Yes, by driving performance and cross-country ability, they are almost Siamese twins, but inside they are completely different. The front row of seats has headrests, the backrest is adjustable in length and angle, the rear row folds to increase luggage space. Upon request, the Niva was equipped with a washer and cleaner rear window, as well as an electric window heater. By today's standards, the equipment of the Volga SUV is almost ascetic, but in the 70s they did not even dream of such luxurious things.

Soul mates!

One of the most significant features of this machine was that the bulk of the parts and assemblies were “thrown” from passenger models the same VAZ (mostly “sixes”). So, on the basis of Soviet engineers, the engine, rear axle and gearbox were designed.

VAZ Niva 21213: technical specifications

Initially, the car was equipped with a 4-cylinder carburetor engine with a volume of 1.6 liters. Next came new modifications, resulting in the line power plants The 1.3-liter engine was replenished, but it was not particularly popular among car enthusiasts.

As for the gearbox, the Niva was equipped with a four-speed manual transmission with synchronizers in forward gear. A little later, the SUV began to be equipped with a more advanced transmission - 5 steps. Don't forget about transfer case, which allowed the SUV to overcome any off-road conditions. The two-stage transfer case with center differential had a forced lock. consisted of cardan shafts of the rear and front axles, as well as an intermediate shaft.

The suspension also had its own technical features. The front was independent, on wishbones with hydraulic shock absorbers, springs and a stabilizer bar, which prevented the car from tipping over when cornering. Rear suspension- dependent, with coil springs, one transverse rod and four longitudinal ones. Like the front one, it was equipped with several hydraulic shock absorbers.

The first modernization of a domestic SUV

Oddly enough, the first modernized Niva model went into mass production only 16 years later. Moreover, practically nothing has changed in the technical part of the car - all the parts and assemblies are from 1977! The exception was new internal combustion engine, but more on that a little later.

The main changes affected only appearance"Niva". New modification differs in a more elongated body and slightly modified brake lights at the rear. By the way, the trunk lid could now only be opened from the passenger compartment. The bumper remains metal, but is now painted light gray. In general, the exterior of the car is not particularly sophisticated or cool. However today off-road tuning VAZ 21213 (“Niva”), which consists of installing snorkels, new disks and other units, allows you to significantly modernize appearance car.

Inside, the changes were also minimal - the seats and instrument panel became similar to Ladovian ones (from the VAZ 2108). What do the owners say? According to reviews, "Niva" 21213 after modernization has become more comfortable, but there are old shortcomings (distortions of the back and constant noise inside) the designers still could not avoid it.

And now about the technical part. Since the beginning of 1993, the modernized version of the Niva has been equipped with a new gasoline engine with an increased working volume - up to 1.7 liters. For the first time it was used on an SUV contactless system ignition The carburetor was also changed. Improved brake system. main gear The gearbox now has a gear ratio of 3.9. The muffler has also undergone minor changes. Now its body is not welded, as before, but rolled (like the Lada of the eighth model).

As practice shows, new improvements in the internal combustion engine and transmission system have made it possible to significantly reduce fuel consumption on the VAZ Niva 21213 SUV. So, per “hundred” the car spends about 13 liters in the city and up to 11 liters on the highway.

Export versions of the Niva had central fuel injection and were equipped with a non-disconnectable wheel drive with a center differential and a transfer case with a reduction row. At the request of the customer, the car could be equipped with French diesel engine from Peugeot with a displacement of 1.9 liters. But, unfortunately, these were only isolated cases.

Conclusion

Despite the fact that today there are many competitors for the Niva 2121, this SUV still was, is and will be the best friend of hunters, fishermen and simply off-road enthusiasts. Thanks to the almost complete absence of electronics, the VAZ 2121 is, perhaps, the only jeep that can conquer any section of the road without problems (with the exception of its Ural counterparts of the UAZ brand).