The rear axle gearbox of the VAZ 2106 is a reliable component, but sometimes it also fails. This is explained by the operating conditions and maintenance of the mechanism. Malfunctions can be of various types, ranging from extraneous noise or oil leakage to a jammed gearbox. Therefore, when the first signs of problems appear, you should not delay repairs.
- Technical characteristics
Gear ratio - Video: determining the gear ratio without removing it from the car
- Gearbox device
Main couple
- Differential
- Other details
- Noise when accelerating
Video: how to determine the source of noise in the rear axle
- Removing the gearbox
Video: replacing the shank seal with RZM “classics”
- Video: REM repair on a “classic”
Functions and principle of operation
The rear axle reducer (RAG) is part of the vehicle transmission. This unit changes the direction and increases the value of torque, which is transmitted from the driveshaft to the axle shafts of the drive wheels . The engine rotates at high speed (from 500 to 5 thousand revolutions per minute), and the task of all transmission elements is to transform the direction and angular speed of the rotational movement of the motor and ensure the efficient operation of the drive wheels.
Technical characteristics of the gearbox
The VAZ 2103 gearbox is suitable for any “classic” VAZ model, but engine performance may change after installing a “non-original” gearbox. This is due to the design features of such a gearbox.
Gear ratio
Each type of REM installed on the VAZ 2101–2107 is characterized by its own gear ratio. The lower the value of this indicator, the more “speedy” the gearbox is. For example, the gear ratio of a “penny” RZM is 4.3; a gearbox with a gear ratio of 4.44 is installed on a “two”, i.e. the VAZ 2102 is a slower car compared to the VAZ 2101. The VAZ 2103 gearbox has a gear ratio of 4, 1, i.e. the speed indicators of this model are higher than those of the “kopek” and “two”. The fastest of the “classic” REMs is the unit for the VAZ 2106: its gear ratio is 3.9.
Video: a simple way to determine the gear ratio of any gearbox
Number of teeth
The gear ratio of the RZM is related to the number of teeth on the gears of the main pair. On a “three-piece” RZM, the drive shaft has 10 teeth, the driven one - 41. The gear ratio is calculated by dividing the second indicator by the first, i.e. 41/10 = 4.1.
The number of teeth can be determined by the gearbox markings. For example, in the inscription “VAZ 2103 1041 4537”:
- VAZ 2103 - gearbox type;
- 10 and 41 - the number of teeth of the drive and driven shafts, respectively;
- 4537 — number of the final drive gear set.
Consequences of installing a non-standard gearbox
You should know that installing a “faster” REM does not mean an automatic increase in vehicle speed. For example, if on a VAZ 2103, instead of the “native” gearbox with a gear ratio of 4.1, you use a VAZ 2106 unit with a gear ratio of 3.9, then the car will become 5% “faster” and the same 5% “weaker”. It means that:
- effective torque will decrease by 5%;
- to accelerate to a certain speed, fewer engine revolutions will be required, i.e., to accelerate, for example, to 120 km/h, 3900 rpm will be enough, instead of 4400. The problem is that now the engine may not have enough power to spin up to 3900 rpm.
Thus, if you installed a non-standard RZM with a different gear ratio on a VAZ 2103, then in order to maintain the dynamic performance of the car, a proportional change in engine power will be required.
Any gearbox can be installed: if it is normal, it will not hum with any gearbox. However, you need to take into account the gear ratio: if you set it with a lower number, the car will be faster, but it will go slower. And vice versa - if you set it with a larger number, it will take longer to accelerate, but go faster. The speedometer readings also change. Don’t forget about the traffic cops: it’s better to install the same one as it should be, and it’s better for the engine.
genchik64
https://vaz-2106.ru/forum/lofiversion/index.php/t5261–600.html
Principle of operation
On a VAZ-2107, the axle gearbox operates in the same way as on all other cars with a classic drive layout. Why classic? The answer is simple: the first cars that were produced earlier had a longitudinal engine. Thus, first came the engine, then came the gearbox, driveshaft, and the final element in the chain was the rear gearbox. VAZ-2107 is built on the same principle. But the next model 2108 has a more modern front-wheel drive layout with a transversely mounted engine. It is believed that this design is safer in terms of getting the car out of a skid. But in this case, all the nodes are concentrated in one place (that is, in the engine compartment). In the case of the “seven”, all elements are placed evenly throughout the body. So, how does the VAZ-2107 gearbox work?
Gearbox device
The design of the RZM is typical of the “classic” VAZ. The main components of the gearbox are the planetary gear and the center differential.
The VAZ 2103 gearbox consists of:
- Bevel drive gear.
- Planetary driven gear.
- Satellites.
- Semi-axial gears.
- Satellite axes.
- Differential boxes.
- Mounting bolts for box bearing caps.
- Differential box bearing caps.
- Bearing adjusting nut.
- Gearbox housing.
Planetary pair
The driving and driven gears, called the planetary pair, form the main gear of the rare earth metal. The axes of these gears are offset from each other and cross without intersecting. Thanks to the use of specially shaped teeth, an optimal engagement spot is obtained. The design of the gears allows several teeth to engage simultaneously . At the same time, more torque is transmitted to the axle shaft, reducing the load on each tooth and increasing the durability of the mechanism.
Bearings
The drive gear is held by two roller bearings of type 6–7705U and 6–7807U. To accurately adjust the relative position of the gears of the main pair, an adjusting washer is placed between the inner bearing and the end of the gear. The thickness of such a ring can vary from 2.55 to 3.35 mm with the possibility of fixation every 0.05 mm. Thanks to the 17 permissible washer sizes, you can quite accurately adjust the position of the gears and ensure their correct engagement.
The rotation of the driven gear is ensured by two bearings of type 6–7707U. To prevent axial displacement of the gears, preload is created in the bearings using tension nuts and spacer plates.
Flange and differential
A flange fixed to the gearbox shank provides connection between the main gear and the cardan shaft. The center bevel differential consists of two satellites, two gears, a box and a satellite axis . The differential allows the rear wheels to rotate at different angular speeds.
Teeth Features
Just like a gearbox, it uses a pair of gears. The VAZ-2107 steering gear is no exception. On the “seven”, the driven and driving gears are located at an angle (that is, not straight, but helical). The main feature of the pair is less load on the teeth, smooth and quiet operation. The rear axle of the “six” and other classic VAZ models is designed using the same principle.
- Cylindrical.
- Conical.
- Worm-shaped.
If we talk about the VAZ-2107 steering gear, then the operating principle here is based on a worm pair. As for the gearboxes themselves, they also include a hypoid gear. Here the gears, unlike bevel gears, do not lie in the same plane.
Signs of a gearbox malfunction
Many REM malfunctions can be diagnosed by the changed sound of the operating machine and the appearance of extraneous noise. If knocking, crunching and other noises are heard from the gearbox when moving, this indicates a malfunction or failure of any part of the unit. If extraneous noise appears in the rear axle, you should pay attention to the oil level in the gearbox and check how correctly the RZM is adjusted (especially if it has been repaired or newly installed).
Crunching sound when moving
If you hear a crunching sound from the gearbox while the car is moving, you should immediately take measures to prevent even greater malfunctions. The appearance of grinding and crunching sounds indicates that bearings or gears will most likely have to be replaced. If the bearings have not yet failed, but are already heavily worn out and do not rotate well, a hum will be heard from the REM side, which is not present when the unit is working properly. Most often, the reasons for the appearance of crackling and humming sounds from the gearbox while the car is moving are:
- unacceptable wear or complete destruction of gears or bearings of the main drive;
- unadjusted gear engagement;
- broken hole for the pinion axle in the differential box;
- low oil level in the gearbox.
Wheel jammed
The reason that one of the rear wheels of the car is jammed may also be a faulty REM. If the driver ignored the appearance of extraneous noise that was caused by the failure of the differential bearings, this may result in deformation of the axle shafts and jamming of the wheels.
Gearbox adjustment
If during engine operation there are signs of a malfunction of the REM, most often it is necessary to dismantle the gearbox and disassemble it. After this, it will be possible to determine what is needed to troubleshoot: adjustment, replacement of individual parts of the REM or installation of a new gearbox.
Removing the gearbox
To dismantle REM, you will need:
- hex wrench 12;
- set of open-end wrenches;
- jack;
- supports for the rear axle;
- wheel shoes;
- container for draining oil.
To dismantle the REM you must:
- Place the car over the inspection hole and place shoes under the front wheels.
- Unscrew the drain plug and drain the oil into a container prepared in advance.
Disassembling the gearbox
To disassemble the REM, you will additionally need a hammer, a drift and a bearing puller. To disassemble the gearbox you will need:
Oil
It is worth noting that the VAZ-2107 gearbox, or rather its operating principle, is based on the meshing of gears. Accordingly, with constant rotation there will be significant production. To increase the service life, special oil is poured inside the gearbox. It forms a thin film behind the teeth. On the “seven” you can use thick gear oil. It is perfect not only for the gearbox, but also for the rear axle. We also note that the lubricant has a certain service life. Experts recommend changing this fluid at least once every thirty thousand kilometers.
Gearbox repair
In the process of repairing the gearbox, it may be necessary to disassemble the rear axle and replace its individual components.
How to halve a bridge
Some car enthusiasts prefer to halve the bridge instead of traditionally dismantling and disassembling it to carry out repairs or adjustments of rare earth elements. This method is available, for example, to owners of UAZ cars: the design of the rear axle of the UAZ allows it to be halved without removing it. To do this you will need:
- Drain the oil.
- Jack up the bridge.
- Place stands under each half.
- Unscrew the fastening bolts.
- Carefully spread the halves apart.
I followed a simple path: I unscrewed the lower ear of the left shock absorber, the brake pipe from the tee to the right wheel, the left stepladders, drained the oil from the axle gearbox, a jack under the apple, a jack under the left side of the bumper, a push of the left wheel sideways and the GP with the differential in hand. Everything about everything - about 30-40 minutes. During assembly, I screwed two pins into the right half of the bridge, like guides, and connected the bridge along them.
Malikoff
https://forum.uazbuka.ru/archive/index.php/t-137742.html
Replacing satellites
Satellites - additional gears - form a symmetrical equal-arm lever and transmit equal forces to the wheels of the car. These parts are in constant engagement with the semi-axial gears and form a load on the axle shafts depending on the position of the machine. If the vehicle is driving on a straight road, the satellites remain stationary. As soon as the car begins to turn or slides onto a bad road (that is, each wheel begins to move along its own path), the satellites come into operation and redistribute the torque between the axle shafts.
Considering the role assigned to satellites in the operation of rare earth metals, most experts recommend replacing these parts with new ones when the slightest signs of wear or destruction appear.
Bridge assembly
After completion of work related to repair, adjustment or replacement of the REM, the rear axle is assembled. The order of assembly is the reverse of disassembly:
- the contact surfaces of the rare earth metal parts and the rear axle housing are cleaned of dirt;
- a new gasket is installed between the gearbox and the beam;
- The REM returns to its place and is securely fixed with mounting bolts;
- The axle shafts, brake drums and wheels are replaced.
Factory RZM gaskets are cardboard, but many drivers successfully use paronite gaskets. The advantages of such gaskets are high heat resistance and the ability to withstand high pressure without changing quality.
Drivers most often trust experienced specialists at a service station to repair and adjust the rare-earth parts of a VAZ 2103 car. This type of work can be done independently if there are appropriate conditions, as well as the necessary tools and materials. At the same time, it is better to do this for the first time under the supervision of an experienced craftsman, if you do not have the skill to independently disassemble, adjust and assemble rare earth metals. It is highly recommended not to delay repairs if extraneous noise appears from the gearbox.
