Do-it-yourself repair of the rear axle gearbox vaz 21053

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 testing 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.

• Thank you
• I do not like