How to properly care for the rear axle of a VAZ 2106

Rear axle section

1 – locking ring of the axle shaft; 2 – brake pad; 3 – brake drum; 4 – wheel mounting bolt; 5 – guide pin; 6 – brake cylinder; 7 – brake shield; 8 – axle bearing; 9 – cuff of the axle shaft; 10 – spring support cup; 11 – differential bearing; 12 – breather; 13 – differential housing; 14 – driven gear of the main gear; 15 – satellite;

16 – semi-axial gear; 17 – bolts securing the gearbox to the rear axle housing; 18 – drive gear bearings; 19 – cuff of the drive gear flange; 20 – flange; 21 – drive gear nut; 22 – dirt-reflecting ring; 23 – spacer sleeve; 24 – adjusting spacer (ring); 25 – drive gear; 26 – satellite axis; 27 – gear housing; 28 – rear axle beam; 29 – axle shaft.

The rear axle of the car is made in the form of a hollow beam, to the ends of which flanges with seats for axle shaft bearings and holes for attaching brake shields are welded. In the middle, a main gear reducer with a differential is bolted to the beam, and on the flange side, two axle shafts are inserted into the beam, transmitting torque from the gearbox to the rear wheels.

The rear axle of all “classic” VAZ cars (except all-wheel drive models) is unified and, depending on the model, can be equipped with a gearbox with a gear ratio of 3.9 or 4.1.

The location of the gear ratio marking on the driven gear.

The drive and driven gears of the gearbox are selected in pairs and if at least one of them is damaged, they are replaced as a set.

The drive gear is mounted on two tapered roller bearings, and an elastic spacer sleeve is inserted between their inner rings. When the nut on the pinion shank is tightened, this bushing is deformed, providing preload to the bearings.

An adjusting ring is installed between the drive gear and its bearing, which determines the axial position of the drive gear.

The final drive gear is bolted to the differential housing, which is mounted on two tapered roller bearings. The preload in these bearings, as well as the amount of clearance between the teeth of the drive and driven gears, are adjusted by ring nuts screwed into split bearing beds. Inside the differential housing, two satellite gears sit freely on the axle and mesh with the semi-axial gears.

The axle shaft with its inner end enters the splined hole of the semi-axial gear, and with its outer end it rests on a ball bearing, which fits into the flange of the beam and is locked there by a plate. The plate, together with the oil deflector and the brake shield, is secured with four bolts to the beam flange. A cuff is installed in the bridge beam socket. The bearing is secured against axial displacement on the axle shaft by a locking ring.

The brake pads, the brake cylinder with the brake fluid supply tube and the parking brake cable sheath are attached to the brake shield.

The brake drum is attached to the axle flange with two guide pins.

For filling and draining oil, two plugs with conical threads are installed.

Copyright © 2007-2019 All rights reserved. All trademarks are property of their respective owners.

The purpose of the rear drive axle of a car is to change the supplied torque and transmit it at an angle of 90° to the drive wheels. During cornering, this axle allows the drive wheelset to rotate at different speeds.

The bridge also transmits reactive torque and traction forces to the supporting body or frame from the drive wheels and perceives lateral reactions and weight forces while the vehicle is moving when turning.

Design features of a continuous rear axle

An automobile rear drive axle consists of the following elements: differential, rear axle housing, wheel drive axle shafts, final drive. The rear axle housing is designed for mounting the necessary components with their mutually specified location, transmitting torque to the drive wheels.

At the same time, the rear axle housing is one of the components in the suspension of the rear wheel pair. The bridge, through the suspension, absorbs the weight of the vehicle transmitted to the wheels.

The rear drive axle housing is made using the stamping method. The crankcase ends are equipped with welded and pressed forged steel flanges, which are machined after welding. The flanges are distinguished by special sockets for mounting axle bearings, as well as threads for fastening the brake shield.

Rear axle differential

That would seem to be all. We have reached the point where the wheels are starting to spin. But a problem arises when changing the direction of movement of the car by turning left, right or when making a U-turn. If the wheels are placed rigidly on the same axle, then they will always rotate equally. And when turning, say, to the right, the turning radii of the wheels change, and the right wheel travels a shorter distance than the left.

It turns out that one of them must slip. The same effect will occur if one of the wheels is rolled through a hole, and the second on a flat surface. This will lead to increased wear of the wheels, and on a slippery road the car will simply be uncontrollable.

This means we need to make sure that the wheels are independent of each other, but at the same time receive torque. This is the task of the next mechanism - the rear axle differential. The rear axle differential is shown in the figure below.

The drive gear meshes with the driven gear, the appearance of which, as can be seen in the figure, has noticeably changed compared to the previous picture. Inside the driven gear, two bevel gears sit rigidly opposite each other. They are called satellites.

Each satellite is coupled with teeth to two gears on the axle shafts. The axle shafts themselves are not directly connected to each other in any way, only through satellites. That is, at this stage the wheels have gained independence from each other.

How does a car's rear axle work?

Now let's look at the operating principle of the rear axle differential.

The car drives straight. Torque from the drive gear is transmitted perpendicularly to the driven gear. The driven gear rotates the satellites together with itself. They, due to the gear engagement with the gears of the axle shafts, force them to rotate equally, and the torque goes to both wheels. At the same time, the satellites themselves do not rotate around their own axis.

The car turns. One of the axle shafts with the wheel must rotate at a lower (higher) speed relative to the second. This is what the satellites allow her to do, which, in addition to rotating together with the driven gear of the main gear, begin to rotate around their own axis.

This rotation allows them to transfer the load unevenly, and the wheels rotate at different speeds. Upon completion of the vehicle maneuver, the satellites freeze and rotate only together with the driven gear, which we discussed above. This is the principle of operation of the rear axle differential.

The final element of a car's drive axle is the same axle shafts that are rigidly connected to the wheels.

All mechanisms of the vehicle's drive axle are protected by a metal case with a crankcase containing transmission oil, which serves to reduce friction and cool moving parts.

Rear axle specifications

In terms of the design and characteristics of the leading axes, all classic Zhiguli cars are the same. The only difference is in the ratio of the main pairs.

Table: characteristics of the rear axle "six"

Gearbox Maintenance

Let's consider the main points of gearbox maintenance.

Radial clearance setting

. Periodic adjustment of the drive axle gearbox makes it possible to prevent tooth wear and also promotes their uniform grinding. Extended radial clearance causes wear on the bearings and teeth of the drive gear shaft and is adjusted using special washers that are placed under the front flanges of the gearbox body. It is characteristic that setting the drive axle gearbox in VAZ vehicles does not differ from the same operation for trucks.

Lubricants

. Adjustment is adjustment, but you must also remember about the working fluid, which is used to lubricate all components of the drive axle gearbox. The most widely used lubricants: domestic - Nigrol or TAD-17, international classification - SAE (72-250) or API (GL-1 - GL-5). The increased viscosity that they are able to maintain at both high and low temperatures allows them to be used to compensate for the high loads that arise during torque conversion.

For the optimal working process of a hypoid gear, it is necessary to maintain the recommended volume of working fluid, since its reduction leads to wear of the teeth of the main pair. But it is also necessary to remember that exceeding the permissible level can cause harm in the situation with VAZ cars by squeezing out the drive axle gearbox seal.

Repair or how not to make a mistake

. Repair of the drive axle gearbox on VAZ cars is carried out in almost any garage cooperative without following the simplest rules for its installation and assembly.

For example, the rear axle gearbox of a Niva car and the front axle gearbox of a Niva car must have the same gear ratios. Violation of this requirement will result in uneven distribution of torque, which can destroy one of the main pairs. There are many cases where would-be repairmen, when repairing the front axle gearbox, made their own modifications.

As a rule, such know-how ends in failure - apart from the failure of the rear and front axle gearboxes, you will not receive anything, and no one will return your money for this “repair”. And if you take, for example, an expensive Mercedes, BMW or Toyota, repairing their rear axle gearboxes will cost you a pretty penny! So, it’s better to turn to professionals and save your money.

The VAZ 2106 rear axle gearbox is the main device that transmits the generated power from the engine to the wheels. This design is used on almost all domestic Soviet-style cars. It has proven itself to be a fairly strong part, but breakdowns still occur.

Timely and high-quality maintenance will help to extend the service life as much as possible.

Despite the fact that there are a large number of cars on which the gearbox is installed, in most cases its structure is the same. Its main task is to transfer force from one device to another. At the same time, the speed of its movement can change the intensity and direction. This is the main purpose of the device in the rear axle system.

Gearbox device

Rear axle gearbox design of VAZ 2106

In order to understand the design of the gearbox, you need to simultaneously consider other parts included in the assembly.

The design of such a unit must be considered together with other elements included in its composition.

The main constituent elements are two parts:

• Main gear;
• Wheel differential.

In addition, it includes:

• Direction pin;
• Drum;
• Bearings and their fastenings;
• Oil seals;
• Breather;
• Satellite;
• Flange and much more.

When the engine is running, a certain force is created. Due to the operation of the gearbox, it moves between the gears. It is the combination of these gears that is called the main gear, which transforms the torque and directs it to the wheels. Due to the cross-axle differential, the load is distributed between the wheels and allows them to rotate at the required frequency when the direction of movement changes. This is exactly how the gearbox works on a VAZ 2106 car. Due to the simplicity of the design, its use is ensured without problems in any conditions.

Rear axle structure of VAZ 2106

The design of the “six” gear consists of the main components: cast, gearbox and driveshaft. Each of them is an integral part, without which the normal functioning of this mechanism is impossible.

Frame

The rear axle housing or support beam consists of two extruded tubular housings connected by welding. On the outside of the housing, flanges with drilled seats for bearings and propeller shaft bushings are welded to prevent lubricant leakage. The flanges have 4 holes for the brake disc bolts on which the brake cylinder and pads are attached. These bolts also hold the oil slurry and plate holding the bearing axle shafts in place. In the middle of the body there is an add-on, which is the oil pan for the rear gearbox. The crankcase has holes for the breather, as well as for filling and draining lubricant. Brackets for attaching rear suspension elements are welded directly to the skin.

Gearbox

The main function of the rear gearbox is to reduce and transmit torque from the cardan drive to the wheels of the rear axle. Structurally, the unit consists of a housing, a pair of main gears, and a differential with rolling bearings. Only the number of teeth on the buffer and planetary gear depends on the gear ratio of the unit. On the VAZ 2106, the number of driven teeth is 43, and the pitch is 11. The gear ratio is set as follows: 43/11 = 3.9.

Half shafts

The main task of the driveshaft is to transmit the torque converted by the gearbox to the wheels of the car. On the one hand, half of the axle has splines that connect it to the gears in the gearbox, and on the other, there is a ball bearing that allows the mechanism to rotate, and a flange for attaching the brake drum and rear wheel.

Device types

The VAZ gearbox can be of various types depending on the components. The main gears have an unusual shape, and the teeth are at a variety of angles. This is explained by the fact that a hypoid type transmission is used. Its main advantage is low noise level, jerk-free operation and reduced load on each tooth. Thus, the entire mechanism can be operated for a long time and, as experience shows, quite reliably. The same gearbox is installed on many other models of domestic cars.

Types of rear axle gearboxes VAZ 2106

In addition, the main transfer can be performed in other ways. For this purpose, transmissions are installed:

However, in most cases, it is the first type that is used, since its efficiency is maximum and its cost is relatively low.

It is also necessary to note the cross-axle differential, which is used to supply torque to the wheels in varying degrees. In other words, this is a planetary gearbox included in the bridge design. A different device is installed on SUVs and crossovers, since their tasks are slightly different.

Rear axle oil

On the VAZ 2106 side, the friction of the internal components of the rear axle is reduced due to the use of GL5 gear oil with a viscosity of 85W-90. The volume of this substance is 1.3 liters. Currently, there are many similar oils, but for Zhiguli cars you can use cheaper ones, for example, TAD-17.

It is recommended to change the lubricant in the rear axle every 50 thousand. km.

Checking the oil level and adding oil

A 17 wrench and a special syringe are needed to check the lubricant level and top up. The procedure consists of the following steps:

1. Park the car on a level surface.
2. Unscrew the oil filler cap and use your finger to check the oil level: it should be level with the bottom edge of the filler hole.

If the oil needs to be changed, simply pour it into a suitable container, drain well, and then add new oil in the required volume.

The rear axle of the VAZ “Six” is a fairly reliable unit and does not require special attention. The need for repairs, if any, is rare. The most common problems are leaking shaft or shaft seal. Replacing them is simple and does not cause any problems. A more complex procedure is replacing the axle bearings or repairing the gearbox. However, these mechanisms can be repaired in a workshop by carefully reading and following the step-by-step instructions.

Repair work

When a VAZ rear axle gearbox fails, there are two options for solving the problem - replace it completely or find the faulty part. The latter option is not always possible, since the mechanism may become completely unusable under further conditions. Therefore, it is advisable to replace it immediately. To do this, you will need a standard set of keys, which almost every motorist has.

It will not be possible to do this procedure in a regular garage, since this will require crawling under the car. Therefore, drive the car onto a lift or place it over a ditch for inspection.

Repair of rear axle gearbox VAZ 2106

So, to remove the rear axle gearbox, you must perform the following steps:

• Remove all oil from the crankcase;
• Remove the left and right axle shaft;
• Remove the rear part of the cardan transmission;
• Remove the gearbox clamp bolts (there are 8 in total) that secure it to the rear axle;
• Remove the gearbox directly.

After this, you will need to separate it from the flange and remove the old gasket. To install a new mechanism on a car, you need to perform all the same steps, only in reverse order.

If you are installing a rear axle gearbox on a VAZ that has already been used, then you need to remove all dirt and so on. Be sure to use good quality new gaskets as this will ensure they last a long time. It is advisable to apply a small layer of sealant in places where fasteners are fixed using bolts. When you tighten the bolts, you need to do this gradually and with little force. After all the work is completed, it will be necessary to pour new oil into the crankcase.

Maintain correctly, carry out repairs and adjustments on time and the gearbox will never let you down!