Do-it-yourself vaz 2104 gearbox repair

In detail: do-it-yourself repair of a vaz 2104 gearbox from a real master for the site my.housecope.com.

We are replacing the rear axle gearbox in the classic VAZ 2101 2107 2105 2106 2104 with our own hands. The work will be done on the example of a penny, but on other "classics" the principle is the same. The old gearbox began to hum unpleasantly when driving, it was decided to replace it. When draining the oil, it turned out that there is a lot of chips on the drain bolt with a built-in magnet.

Video of replacing the rear axle gearbox in the classic VAZ 2101 2107 2105 2106 2104:

The new gearbox turned out to be of terrible quality, there was no crimp spring on the oil seal, as a result of which it leaked oil, the oil seal itself was mechanically damaged. Although a replacement for this part was bought in the store, it did not help. After the oil was poured, the car was started, the new gearbox howled so hard that it blocked the ears. These are the new parts we make and sell.

As a result, it was decided to send the old gearbox, which has served faithfully for several years, for repair to a special office, where, at a special stand, they change the pair and give it completely serviceable with a guarantee.

The video will still be useful, since the gearbox will have to be removed, this is not difficult, but not entirely simple, it will take you more than one hour of time.

By itself, replacing the VAZ-2107 rear axle gearbox is a procedure that is rarely carried out. The thing is that this node is considered one of the most reliable and resistant to external factors.

How exactly to do everything with your own hands, we will tell you below.

In most cases, disassembling the gearbox is required to replace the oil seal. Like all rubber gaskets, it often starts to leak, as:

loses elasticity over time;
may have a manufacturing defect;
was originally installed incorrectly.

Problems with the oil seal are indicated, in particular, by the following symptoms:

Video (click to play).

oil stains are periodically found at the rear axle;
a backlash forms at the shank of the gearbox (always radial).

The latter also indicates the wear of one bearing or several at once.

The fact that the rear axle is defective will also be indicated by an atypical noise coming from the trunk. Here it is important to find out at what speed it occurs. For this:

accelerate to 20 km;
continue to accelerate smoothly to 90;
fix the engine speed at the time the noise appears;
release the gas, but do not engage the gear;
in the process of braking by the power plant, observe the nature of the sounds.

The following test exactly says about the breakdown of the gearbox:

accelerate the VAZ-2107 to 100 km;
set "neutral";
turn off the ignition.

If the buzz is still audible, then it is the gearbox that is to blame.

Drain all oil from the gearbox before disassembling the gearbox. Remember - never reuse old grease.

To free the rear axle, put the car in neutral.

raise the tailgate with a jack;
the cardan joint, carefully holding it with a pry bar (so that it does not turn in the process), is disconnected from the drive gear;
unscrew the 4 nuts fixing it;
taking a flat screwdriver, detach the flange;
the cardan is suspended on a rope, fastened to the bottom of the machine;
twist the nut securing the drive gear;
remove the washer;
the flange itself is dismantled;
release the brakes and unscrew the wheels.

Since it is impossible to replace the gearbox without removing the axle shafts, dismantle them as well.

After that, it remains only to remove the gearbox itself. It is disconnected from the beam by unscrewing 8 bolts.

Whatever reason makes you disassemble the rear axle, always check the condition of other moving parts along the way. As previously noted, oil seals most often become unusable.

The main bearings also often wear out due to high loads. Having found visible defects on these elements, they must be changed. By the way, this element is designed to ensure the correct gear ratio of the power unit. Those who intend to tune their "seven", it is useful to know - installing a superior gear directly into the gearbox allows you to lower the above-mentioned indicator and, therefore, increase the speed. For 2107, the largest number allowed is 4.4.

After the repair has been completed and all elements that have become unusable have been replaced, it is necessary to assemble the rear axle and be sure to make sure that the gearbox no longer makes noise when driving.

The process looks like this:

the new node is fixed in the place intended for it;
return the axle shafts to the bridge;
the gear flange is attached to the cardan;
install wheels and brake drives.

It is necessary to test the car at both low and high revs. First of all, leaving the car in neutral, step on the gas. Then accelerate smoothly and then turn off the engine. In a situation where the noise is still audible, an unambiguous conclusion should be made: you made some mistake or the cause was not in the gearbox.

When the car moves without extraneous sounds, you can safely operate it as usual.

In the absence of proper experience, do not try to repair the car yourself. Contact a car service with a problem or, in extreme cases, call for help from a friend who has a stock of the necessary knowledge and skills.

This video will help you better understand the issue of replacing the gearbox:

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The torque from the gearbox is transmitted to the rear wheels of the “seven” through the rear axle reducer. The gears installed in the gearbox wear out over time and begin to make noise when driving. In this case, you will have to change or repair the gearbox of the rear axle VAZ 2107.

As the name implies, the VAZ 2107 gearbox is located in the rear of the car. It is located inside the rear axle, and is bolted to it with eight bolts. On the other side of the gearbox, to the flange, the propeller shaft of the car is screwed.

A gearbox is a rather expensive part, and its repair is a laborious and complicated process. Therefore, you should first make sure that the cause of the noise is precisely a gearbox malfunction. This can be done as follows:

Choose a flat section of the road and gradually accelerate on it from 20 to 90 km / h. While driving, you should listen carefully and note the appearance and disappearance of extraneous noise from the side of the rear axle gearbox.
Release the gas by starting to brake with the engine. While the speed is decelerating, you should also note the moments when the noise appears and disappears.
Accelerate the car to about 100 km / h and switch to neutral, turn off the engine. While the car is rolling by inertia, note the presence and disappearance of noise.

[tip] If the rear axle hums with both engaged and disengaged gear, there are no problems with the gearbox. If the noise is observed only when the gear is engaged, repair or replacement of the VAZ 2107 rear axle gearbox is necessary. [/ Tip]

To verify the presence or absence of a mono problem like this:

Park the machine using wheel chocks.
Jack up the rear axle.
Start the engine, turn on the speed and add gas so that the wheels rotate without load, and the speedometer shows the same speed as when tested on the move.

If, when running without load, the noise remains the same as under load, the problem is not with the gearbox. Check other components of the rear drive.

If the gearbox does not make noise without load, you will have to deal with its restoration. Worn gears only start to make noise under load.

The design of the gearbox is quite reliable and the "seven" can travel 100-300 thousand kilometers without repairing the rear axle. Premature wear of the gears only occurs with improper use:

untimely replacement of transmission oil;
the use of low-quality oil;
operation of the bridge with insufficient oil level;
frequent vehicle slippage or operation under extreme load conditions.

To repair the rear axle of a VAZ 2107, you will need:

a set of spanner wrenches;
chisel;
drift;
hammer;
bearing ring puller;
pencil;
container for transmission oil;
torque wrench;
set of probes:
calipers.

Work must be carried out on a lift or inspection pit.

Before removing the gearbox, it is necessary to drain the transmission oil, which is poured into the rear axle of the VAZ 2107. To do this, place a container for oil under the drain hole of the axle and unscrew the drain plug.

Important: after repairs, fill the gearbox with new gear oil.

The subsequent procedure is as follows:

unscrew the bolts securing the cardan to the gearbox flange;
undock the back of the cardan and lower it down;
jack up the car (if it is not on a lift) and remove the rear wheels;
unscrew the guide screws of the brake drums;
remove the brake drums;
unscrew 4 bolts securing the axle shafts;
pull out the axle shafts by freeing the gearbox;
unscrew the 8 bolts securing the gearbox;
remove the gearbox.

[tip] Tip: after removing the axle shafts, it is worth checking the condition of the bearings and, if necessary, replacing them. [/ tip]

Adjusting and repairing a gearbox requires some skill and careful adherence to technology. You also need pullers, stands and special tools. If the above is not there, you should entrust the work to professionals.

If your qualifications are insufficient, it is better not to start working with the gearbox. Assembly and adjustment work requires fairly high locksmith skills. It is not difficult to disassemble the VAZ 2107 bridge, but it is one of the few nodes of the “seven” that require highly qualified service. It is not worth saving on these works.

Disassembly of the gearbox is carried out in the following sequence:

unscrew the shank nut;
remove the flange and take out the drive gear and adjusting rings;
remove the oil seal, oil deflector, inner ring of the bearing;
press out the outer rings of the bearings with a puller;
disassemble the drive gear with the differential (the spacer sleeve must be replaced in this case).

When disassembling the gearbox, it is necessary to make marks on the bearing caps in order to then reinstall them in their previous position. To do this, you can use a core (which is more reliable) or a pencil. Marks must be applied to the covers and to the case, so that later during assembly they must be combined. You should also mark the left and right covers so as not to confuse them in places.

This can be done as follows: on the covers, in addition to the marks opposite the marks on the case, apply numbers or letters with a pencil. The method is bad in that when cleaning the cover, the marks will be erased. Therefore, it is safer to simply make the marks with a core. For example, one on the left cover and two on the right.

The inner rings with a cage are removed with a hammer and punch. It is necessary to knock out the rings by lightly tapping on different places. If you hit only one place, the ring cannot be pulled out.

Usually the repair consists of replacing the bearings or the main pair. These parts are most likely to fail.

The main pair is produced in several variations and determines the gear ratio of the gearbox. The higher the gear ratio - the more traction, the lower - the higher the maximum speed of the machine.There are three standard options for the main pair used on different VAZ models.

All VAZ-classic cars are rear-wheel drive, the movement of the car is carried out by the rear axle, which is the leading one. The VAZ rear axle reducer is the most important part in the transmission, it is in it that the main gear is located.

In order for the car to move, it is necessary to transfer the rotation of the engine to the wheels. But the engine speed is too high, and in order to correctly distribute the torque, a mechanism is needed that changes the gear ratio. Due to the gearbox and the different speed of the internal combustion engine, the speed of the movement changes, and the main pair of the rear axle takes over the rotation and transfers it to the wheels through the gears.

The VAZ rear axle reducer consists of the following parts:

flange, it is fixed on the drive gear (shank) of the REM, is an intermediate link between the propeller shaft and this gear;
the main pair shank, at one end of which there are splines for pressing in the flange, at the other end there is a bevel gear with a small number of teeth;
the driven gear (planetary), it is in mesh with the driving gear, it is with it that it forms the main gear;
center differential, which allows the rear wheels to rotate at different angular speeds.

The differential device is very simple - the mechanism consists of two semi-axle gears, two satellites and a pin of the satellites. From the ZM gearbox, the movement is transmitted to the axle shafts, on which the wheels are fixed.

REMs differ in the gear ratio of the main pair; in total, there are four types of gearboxes on the VAZ-classics:

The most "slow" is RZM 2102, its drive gear has 9 teeth, on the driven gear there are 40 of them. To calculate the gear ratio of the gearbox, the number of planetary gear teeth must be divided by the number of teeth on the drive shaft, for VAZ 2102 the PCh turns out to be 4.44.

The "penny" gearbox (2101) accordingly has the number of teeth on the gears of 10/43, so its frequency converter equals 4.3. The next, more high-speed, is REM 2103 - it has a ratio of 1041, which means that the gear ratio is 4.1. And finally, the "fastest" gearbox will be 2106, with 11/43 teeth and 3.9 gears, respectively.

Many owners of VAZ 2101-07 strive to install the fastest gearbox, but this is not always necessary. If the car often carries a load, that is, the car is a "workhorse", high speed is useless, but high torque will be very useful. It should be noted that RZM 2102 was not supplied in spare parts, it was installed only on station wagons "deuces".

VAZ 2107 is the last car from the series of rear-wheel drive VAZs - it began to be produced later than anyone else and was produced from the whole "Classic" for the longest time, its production ended in 2012. All types of gearboxes were installed on the machine, except for 2102, the choice of REM depended on the type and power of the engine.

The main disease of REM is increased noise (hum), and the gearbox can hum for various reasons:

there is not enough oil in the bridge, or it is completely absent;
the gap between the gears of the main pair is not adjusted;
gears are worn out, they have chips and other damage;
the main pair has a factory defect, the gears are not lapped from the factory;
the shank nut has been unscrewed or loosened;
the bearings are worn out.

The main malfunction of the center differential is the wear of the gears of the axle shafts and satellites, when the surfaces of the parts are very worn out, a backlash forms between the gears of the differential, but the rear axle usually does not make noise due to wear of the differential gears.

ZM gearboxes on VAZ-classics can be repaired, but only if there is no wear on the gears. If the mechanism is already beyond repair, it needs to be replaced. Replacing the gearbox of the rear axle VAZ 2106 on the "seven" is carried out as follows:

we install the car on a pit or a car lift, changing the gearbox on the ground is extremely inconvenient;
if the vehicle is installed in a pit, both sides must be jacked; in any case, the rear wheels must be removed. If the work is not done on a lift, you should install stops under each side of the car (in the back);
we unscrew the drain plug in the REM, drain the transmission oil, having previously prepared a container for it;
remove the rear brake drums (two guide bolts on each side), after removing the car from the parking brake. The drums can be difficult to remove, they are dismantled by tapping from behind with a hammer through a wooden block. Do not knock on the drum with a metal hammer, the drum may crack;

With this, the removal of the ZM gearbox can be considered complete, now it remains to either repair the mechanism, or install a new one instead.

Increased backlash in the REM can form due to wear on the pin of the differential satellites - if you take hold of the propeller shaft and turn it clockwise and counterclockwise, you can feel this backlash. Also, an increased clearance can form due to wear of the splines inside the housing of the differential itself.

If the gaps in the main pair of ZM are not adjusted, a characteristic noise occurs when the car is moving:

with an increase in the load (a sharp increase in speed), a characteristic howl in the bridge is heard;
when the gas is released, the noise disappears.

The ZM can buzz in a different way, but the above-described characteristic feature can most often be heard on VAZ-classic cars. The worn out teeth of the main pair are clearly visible on the "planetary" - they become rounded, and traces of rust are often noted on them.

If the main pair in the gearbox is worn out, it must be replaced. But you can't just put the gears in place, the clearances in them must be adjusted. In total, two types of basic adjustments are performed:

the thickness of the adjusting sleeve (washer) is selected for the shank (drive gear). The washer can be between 2.6mm and 3.5mm thick;
the gap between the gears of the main pair is adjusted by two adjusting nuts of the differential housing.

The washer for the shank is selected in such a way that the shaft with the leading bevel gear rotates in the gearbox housing without play with a hand force (0.3-0.4 kg). In this case, the shank nut should be tightened with a force from 12 to 26 kg, usually 18-19 kg are tightened.

After installing the shank, the differential housing is put in place with the planetary gear fixed to it. The body is fastened with two covers (4 bolts, a knob with a head of 17). Adjusting nuts are screwed on the sides of the bearings, the differential is set so that there is a play between the gears of the main pair, the planetary gear should not be clamped. By moving the adjusting nuts to the right and left, the shank gear is brought to the planetary gear. The adjustment selects the moment when the gap between the gears practically disappears.

The last step is to adjust the preload of the differential bearings, the adjusting nuts are tightened from the sides. Such work must be done with an indicator, the device should show from 0.14 to 0.18 mm, the gap between the gears should be within 0.08-0.13 mm. After the performed operation, the adjusting nuts are fixed with plates so that they do not turn.

It should be noted that adjusting the VAZ rear axle gearbox is a very difficult matter, and it is better to trust it to professionals.

Car owners of VAZ classics often cannot decide what is better to do - to buy a completely finished REM assembly or purchase individual parts, repair the gearbox. It is really difficult to decide here - the price of a new gearbox is, of course, higher, but the owner of the car is freed from the headache with adjustment. The thing is that it is not so easy to find a good master of VAZ gearboxes, and there is no guarantee that the new main pair will not hum.

If the car owner buys a new gearbox, and it hums, the part can be exchanged under warranty, but the owner of the car loses money on removing and installing REM.In the case of acquiring a defective main pair, the repair itself is more expensive - you will have to pay the master for the secondary bulkhead of the ZM gearbox.

On VAZ 2101-07 cars, the factory blocking of the center differential is not provided, but the industry already produces both differentials with blocking and fully assembled ZM gearboxes. The most common today are REMs with a screw lock, in which the differential gears are locked depending on the load. In such rear axle gearboxes, a preload clutch is installed, it connects the axle shafts of the wheels with a certain effort, and acts as a blocker.

Blocking the VAZ rear axle gearbox gives the following advantages:

increases cross-country ability, allows the car not to slip on difficult road sections;
allows the car to accelerate faster at the start;
the car passes corners more confidently.

But ZM gearboxes with screw locking also have their drawbacks:

fuel consumption increases slightly;
when accelerating, the car is less controlled;
the differential and the assembled gearbox with blocking are much more expensive than standard parts (the price is approximately 2-2.5 times higher).

Car owners of VAZ 2101-07 should be aware that after installing a REM with a lock, the car will not become an SUV, and it will not be able to move on difficult terrain.

We welcome motorists of classic vaz models in the autoblog.In these videos, we will consider the vaz 2107 gearbox and adjustment. Nikolai Vladimirovich dedicated the video to the owners of rear-wheel drive cars, since today there is a trend in the rear axle gearbox. The gearbox of the rear axle VAZ 2107, a common domestic car, was shown as a visual aid for repair and adjustment.The main elements of the gearbox are helical gears of the main drive, these are the so-called "beetle" and "planetary gear" that make up the main gear pair. The plant produced four versions of the main steam:

Low-speed, installed on a VAZ 2102. The pair has 9 teeth on a bevel gear and 40 planetary gears. The torque transfer number is 4.44, this is a slow-speed option. Out of production;

On the VAZ 2101 - the famous "kopeck", the main pair had 10 teeth on the "tip" and 43 on the "planetary", with a gear ratio of 4.3, discontinued;

VAZ 2103, respectively, 10 teeth on the "tip" and 41 on the "planetary";

VAZ 2106 - 11 teeth on the "tip" and 43 on the "planetary", gear ratio 3.9, is considered a high-speed reducer.

It should be noted that the main pair with a gear ratio of 4.44 for the VAZ 2102 for spare parts, generally speaking, was not produced and was intended only to complete the gearboxes of the VAZ 2102 on the factory conveyor.The planetary gear is attached to the differential housing. The differential consists of two semi-axle gears, two satellites and a pin. The main, most common differential malfunctions are the wear of the pin of the satellites (backlash) and wear of the splines on the gears of the axle shafts.On a car, the backlash of the pin of the satellites can be determined by turning the propeller shaft by a quarter or more, if there is no backlash, then the shaft practically remains in place when you try to turn it in one direction or the other.It's also worth noting that there is never any noise from the differential. When moving forward (in a straight line), the differential rotates as one whole and it turns out that there is simply nothing to make noise there.The reason for the noise from the rear axle reducer when adding gas and the disappearance of noise after the gas is released is (almost 99.9%) wear of the teeth of the main pair. This is clearly visible on the removed gearbox. The portion of the side of the teeth that is used for the forward travel has significant wear, while the side for the reverse travel is practically not worn.If, after disassembling and troubleshooting the parts of the main pair, wear of the teeth is found, then no repairs will help and it will just be a waste of time and money. Only the replacement of the main pair is required.The gears of the main pair are selected at the factory according to the contact patch, noise and other parameters and are marked. For example, the planetary gears are stamped - vaz 2103 (model), 10 41 (gear ratio), 4091 (pair number). The main pair number 4091 is also marked on the bevel gear.After marking these parts, they became the "main pair" and are not installed one without the other, that is, "relatives". On the "tip" is also marked "- 6", this is a correction for the assembly of the main pair in the gearbox. When troubleshooting the differential, its bearings are also checked for wear and, if necessary, replaced. Often, bearing wear is provoked by an unprofessional replacement of the gearbox oil seal. Image - DIY VAZ 2104 gearbox repair

For example, after replacing the oil seal, the shank nut is tightened without observing the tightening torque (pulling as much as there is force) and the force is transferred not to the spacer sleeve, but to the differential bearings.

As a result, after a short mileage after replacing the shank oil seal, the gearbox noise appears. Only in this case the “hum” noise in the gearbox is constant and unlike the noise from worn out teeth of the main gear. In this case, the hum goes on constantly, regardless of whether gas is added or discharged.

During assembly, the gearbox is regulated by 4 parameters:1. Selection of the adjusting ringParameters from 2.6 to 3.5. The ring serves to adjust the depth of engagement of the teeth of the "tip" and "planetary", which is strictly specified. This is where the -6 correction is needed for this main pair, which was mentioned above. Of course, this correction will be individual for each main pair.In this video, the adjustment of the main pair will be performed using a special device. It is clear that the overwhelming majority of motorists do not have such a device, and this is only a clear example of adjusting the engagement depth parameter. An option will also be given for adjustment without "adapting".The device is also equipped with a "fit" with a micrometer, imitating the gear wheel of the main pair. The indicator is set to zero. Then the indicator leg is transferred to the bearing bed, and in this case the indicator shows a value of - 3.25, which is not good, as it should lie within - 3.0. On the second landing plane it turned out - 3.45. Arithmetic mean - 3.3. To adjust, we will use the correction on the "tip" - "- 6". In this case (- 3.3) + (-6) = 3.36. The thickness of the adjusting washer is required - 3.36 mm. Using a micrometer, select a washer of the required thickness.Note. When the shank bearing is worn out, it starts to turn on the body of the “tip”. As a result, the bearing end, the shim and the shank gear bodies wear out. It turns out that when replacing the oil seal of the shank, even with the correct tightening torque, the adjustment of the depth of engagement of the teeth of the gears of the main pair is lost and the "howl" of the pair is ensured, as is its early failure.2. Adjusting the preload of the shank bearingsThe shank bearing sits on the "tip" and a NEW spacer sleeve is ALWAYS installed. The video clearly shows that the new bushing is flat without any deformation, and the previously standing one is deformed. The following happens. When the shank nut is tightened to the prescribed torque (from 12 to 26 kgf), the sleeve takes on the tightening force and, being deformed, works like a spring, creating an interference fit. The tightening force of the VAZ 2107-e gearbox nut is significant and the shank must be secured against turning.In the video we see what kind of "adapt" the master uses. It is necessary to tighten the shank nut until the backlash disappears. With the correct tightening of the nut, the shank should turn with a resistance force of 0.3-0.4 kg, therefore, the bearing preload is correct. This assembly rule applies to old (used) bearings.A differential with bearings is installed and secured with covers (tightening torque is about 8 kgf) and the adjusting nuts of the differential bearings are attached.3 and 4.Simultaneous adjustment of the thermal clearance of the main pair and the preload of the differential bearingsFor these purposes, another "adaptation" with two indicators is needed. The adjusting nuts in the video are good and everything is shown, we move the planetary gear to the teeth of the "tip", achieving the required clearance. Factory data for clearance adjustment from 0.08 to 0.12 mm. However, such a gap is provided for the new main pair ("tips" and "planetary"). The clearance is checked in 4 planes by turning the gear. The clearance for the main pair in operation is 0.13-0.14 mm after adjustment.After making the adjustment, the adjusting nuts are locked with special plates, with one or two "tendrils". This completes the assembly and adjustment.

Only a few can correctly diagnose and adjust the rear gearbox of the VAZ 2106

It is easier to sell a new one than to adjust or restore an old one, the more certain knowledge is needed for this, and it costs as much as a qualified adjustment. Therefore, we decided to theoretically shoe the owners of classic Zhiguli, so that if something happens, you can confidently remove, adjust, repair and install a full-fledged working unit with your own hands. But first, a few words about the gearbox device.

The rear axle reducer in all classic VAZ models is installed in the rear axle housing and consists of two main units:

conical main gear of hypoid type;
cross-axle differential.

The differential has the same design on all rear-wheel drive vehicles, with the exception of the all-wheel drive Niva. A limited-slip differential is sometimes installed there. But on six he is useless, so let's leave him alone for now.

Video tips for replacing the rear axle gearbox on VAZ cars

The main transmission is of a hypoid type, made in the form of two helical gears - a leading and a driven. The drive gear is rigidly connected to the propeller shaft of the car, mounted on the shaft on bearings pressed into the crankcase. The pinion shaft is connected to the cardan mounting flange with a splined connection and is locked with a nut, which adjusts the bearing play, but more on that later. The driven gear is fixed to the differential housing, and rotates with it on bearings. They are secured with adjusting nuts, which adjust the clearance between the teeth in the meshing of the main gear. Rotation on the axle shaft is transmitted by means of bevel gears that mesh with the gears of the differential satellites. A bit confusing, but if you look at the diagram, everything becomes clear at once.

Technologically, the easiest way is to transfer rotation from one bevel gear to another when they are on the same axis.But in the gearboxes of rear-wheel drive vehicles, a transmission with axles offset by 31.8 mm is used. This complication of the design is due to the fact that, together with the lateral slippage of the teeth, the hypoid transmission forces the teeth to slip longitudinally.

In the photo, the gearbox of the rear axle VAZ 2106, the cost of which is 6-7 thousand rubles

And this, in turn, gave the following advantages:

long service life of gears;
noiselessness of work;
quick grinding of teeth;
increased ground clearance.

In case of severe wear or damage, both gears of the main drive change only in pairs. The fact is that in preparation for sending ready-made sets of spare parts, pairs are selected on special precision equipment, taking into account the tolerance, the amendment of which is applied to the drive gear shaft. On the driven gear, you can read all the necessary information about the gearbox model - the gear ratio (on the VAZ 2106 it is 11/43), model 2106, serial number and release date.

In principle, one of four sets of final drive gears can be installed in a gearbox of any Zhiguli model. They differ only in the number of teeth, and this dictates the gear ratio. Needless to say, what value this parameter has when choosing a gearbox. It affects both the top speed of the vehicle and the implementation of the engine torque. As garage tuners say, "it either pulls better or drives faster." In some ways they are right.

However, as we already mentioned, there are only four options for the final drive pairs:

VAZ 2101 - 43/10 with a gear ratio of 4.3;
VAZ 2102 - 40/9, the most high-torque gearbox with a gear ratio of 4.44;
VAZ 2103 - 41/10, this is the most running average balanced version of the gear ratio - 4.1;
VAZ 2106 - 43/11, is the fastest gearbox, especially when paired with a five-speed gearbox, and its number is 3.9.

This set gives classic owners endless possibilities to customize the dynamic characteristics of the car. No "tuning" is able to change the dynamics of the classics as much as the rear axle gearbox.

So, for certain purposes, you can buy a certain gearbox, which will change the maximum speed of the car, acceleration dynamics, fuel consumption, and tractive effort. The most "cargo" gearbox from 2102, a penny in the station wagon. Its maximum speed is low, about 145 km / h, but the car confidently drags rather serious loads and trailers without overloading the engine. You need to know the measure, but the fact remains. If you need a small tractor in the back of a Zhiguli, there is a 2102 gearbox with a gear ratio of 4.44 and the number of teeth 40/9. This gearbox has become a rarity, but if desired, the main pair can be found both new and used. The other extreme is the VAZ 2106 gearbox. It will give the car a high maximum speed, but it will not pull from the spot, because as a result the tractive effort is less than that of a two.

If you properly adjust the gearbox, it will serve for a very long time.

A gearbox made according to technology and well-adjusted can serve for decades without reminding itself of anything at all. No noise, no hum, no ringing. This was the case until recently, but two popular products appeared on the market - fake gear oil, and a few years later, fake rear VAZ gearboxes. In most cases, everything that is sold in car dealerships and outwardly resembles a gearbox, in fact, just a pile of metal, unusable. The fact is that high-quality adjustment of the gearbox, which is necessary, requires serious skills and cunning measuring equipment. Here, there can be no question of any adjustment by eye. And most service stations do just that, not realizing that they are simply killing a healthy gearbox. After replacement, it is possible to check the performance of such a unit only on the go. Therefore, they are washed, painted with beautiful paint and placed on store shelves next to counterfeit grease.We will talk about lubrication separately, and now a little about the main faults of the VAZ 2106 gearbox.

As in all units that have a closed lubricated volume, the shank oil seal can leak in the gearbox. This is noticeable right away, since after parking the drops of the transmission under the rear axle will speak eloquently about this. It may be that it is not the oil seal that is to blame for the oil leak, but the loosened bolts of the gearbox to the rear axle housing. But the most common symptom of a gearbox malfunction is noise. The unit can make noise in different ways and in different modes, therefore, no master can give any specific recommendations without listening to it personally. Nevertheless, there are the most common noise manifestations, which we will briefly discuss.

The main source of noise is a worn main pair. This sound cannot be confused with anything, but it appears under load. It is worth dropping the gas, the noise disappears, and the active phase occurs again after pressing the gas pedal. This malfunction is treated only by replacing the main pair. Experimental lovers can add magic additives to the lubricant, but, as a rule, these dubious agents do not restore the main pair, do not know how to adjust clearances, and do not change bearings.

Gearbox bearing noise is fairly easy to identify. They buzz under any load, and in the most neglected cases they can even crackle at low speeds.

Apart from replacement, there are no troubleshooting options. Unless the noise is caused by improper tightening of the shank nut after replacing the packing. Incorrect gearbox adjustment can also cause hum, but it is almost impossible to describe this noise, because it manifests itself in a different way for each gearbox. The adjustment of the engagement is carried out only if there are measuring instruments, torque wrenches, the necessary probes and, most importantly, experience in this matter. Incorrect adjustment can spoil a good gearbox literally a thousand kilometers away.

Unit noise is a common symptom of a gear unit malfunction.

Video (click to play).

Another source of gearbox noise is loosening the shank nut. It appears due to the fact that the spacer sleeve sags, the play in the bearing increases, the nut loosens. The reason is insufficient tightening torque of the nut when replacing the stuffing box or the disgusting quality of the metal of the spacer sleeve. In order for the gearbox to serve for a long time and cheerfully, only certified transmission lubricants need to be poured into it, preferably exactly those indicated by AvtoVAZ, observing the replacement frequency of 10-15 thousand kilometers.