Replacing the rear axle of Lada 2107 (VAZ 2107)

Purpose of the rear axle gearbox of the VAZ 2107

The main traction unit of a car is the engine. It is the source of energy that is necessary to move the vehicle.

In this case, direct transfer of energy from the crankshaft to the wheels is impossible - the latter will rotate too quickly, and driving the car will become an impossible task.

That is why two components act as “intermediaries” - the gearbox and the rear axle gearbox.

It would seem that one gearbox would be enough to transfer energy (as is done on a motorcycle). But it's not that simple.

A car has not one, but two wheels on an axle, and each of them must rotate at the same speed.

That is why the gearbox is an indispensable component of the car - it “distributes” rotation to both wheels.

In fact, two important devices are hidden in one unit - a differential (its task is to distribute energy to the wheels in equal proportions) and a gearbox (it is designed to reduce the speed of rotation of the shaft).

Device

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 different engine speeds, the speed of movement changes, and the main pair of the rear axle takes over the rotation and transmits it to the wheels through gears.

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

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

Diagnosis of axle gearbox failures

Gearbox malfunctions manifest themselves by the appearance of strange noise while driving. But the difficulty is that determining the source of extraneous sound is not so easy.

To accurately identify the cause, it is worth conducting a small diagnosis:

Accelerate the car on a flat road to 20-25 km/h and continue to increase speed (it is advisable to do this as smoothly as possible).

At the same time, listen to unnecessary sounds and record at what speed they appear and disappear.

Having accelerated to the desired speed, release the gas and gradually reduce the speed with the engine. Listen again to the moment when the noise becomes louder or disappears altogether.

Most often, extraneous sound in the gearbox should appear and disappear at the same speed;

Accelerate the car to 90-100 km/h and move the gearshift knob to neutral position.

Now turn off the ignition and drive the car (the car should stop on its own).

Pay attention to noises when reducing speed. If during such a test a suspicious sound appeared, then it clearly did not come from the main gear gears.

If there was extraneous noise during the first test, but not during the second test, then the problem is in the gearbox or drive gear bearing;

Stop the car and gradually increase the speed. If noises appear similar to those in the first check, then the problem is not in the gearbox.

If there are extraneous sounds only during the first experiment, and their absence in the second and third, you can safely “sin” the gearbox.

Repair or replacement, which is better?

Car owners of VAZ classics often cannot decide what is best to do - buy a complete ready-made REM assembled or purchase individual parts and repair the gearbox. It’s really difficult to decide here - the price of a new gearbox, of course, is higher, but the owner of the car is freed from the headache of adjustment. The thing is that it’s not so easy to find a good specialist in VAZ gearboxes, and there is no guarantee that the new main pair will not hum.

If a car owner buys a new gearbox, but it hums, the part can be exchanged under warranty, but the car owner loses money on removing and installing the gearbox. If you purchase a defective main pair, the repair itself will be more expensive - you will have to pay a technician for a secondary overhaul of the gearbox.

Features of replacing the rear axle gearbox

If you are convinced that such an important unit is faulty, then only replacing the rear axle gearbox of the VAZ 2107 can help out. In principle, this work can be easily done with your own hands:

Drive the car onto the overpass (you can work in a pit in the garage).
Place wheel chocks under the wheels (if you don’t have them, you can put regular stone or brick).
Drain the oil from the gearbox (before doing this, it is advisable to drive the car a little to warm up the lubricant).
Wait until all the oil has drained from the assembly.
Remove both rear wheels one at a time and install supports.
Remove the brake drums and axle shafts (it is better to remove the latter rather than leave it dangling from the car).
Unscrew the gearbox and cardan.
Make sure the gasket is intact and, if necessary, treat it with sealant.
After 10-15 minutes, install a new gearbox and assemble everything in the reverse order.
Add oil.

That's all. Now you know why a rear axle gearbox is needed, how to determine its malfunction and replace it. Good luck on the roads and of course no breakdowns.

The rear axle of the VAZ 2107 must be removed to repair the gearbox or to completely replace it in the event of its complete failure. It is most convenient to carry out work in a pit, and the car must be installed in such a way that the rear axle gearbox is not above the pit.

Having driven the car into a pit, hang the rear part of the body so that you can remove the wheels. Place a jack under the gearbox and raise the rear axle slightly. In this situation, do the following:

Disconnect the rear shock absorber lower mounting brackets.
Drain the transmission oil from the gearbox into a previously prepared clean container.
Disconnect the brake pressure regulator mounting bracket, then disconnect the tee with brake pipes from the bridge. Remove the rubber hose for the hydraulic brakes.
Next, you need to disconnect the driveshaft from the gearbox drive flange. Before unscrewing the nut of the fastening bolts, apply a mark to the propeller shaft and the gearbox flange, which you will use as a guide during assembly if the axle is removed for repair and not replacement.
Lower the rear axle a little with a jack to loosen the rear springs and remove them along with the rubber gaskets.
Disconnect the parking brake tips from the brake flaps.
At the final stage of removing the rear axle, all that remains is to disconnect the upper and lower reaction rods, as well as the transverse rod. Place shims under the axle so that when the axle is disconnected, it rests on them and remove the rear suspension rods.

After the rear axle of the VAZ 2107 is disconnected, remove it together with an assistant from the supports and take it to the side. This completes the repair work. Install the axle in the reverse order of removal, fill the gearbox with transmission oil, connect the parking brake cable and bleed the rear brake circuit.

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

Where is the gearbox located?

On the "sevens", as on all representatives of the rear-wheel drive family, the gearbox is located at the rear, under the bottom of the car. It connects the cardan to the VAZ 2107 axle and causes the wheels of the car to rotate. Rotation occurs thanks to axle shafts engaged in the gearbox, which, due to the technical features of the rear axle of the VAZ 2107, will have to be removed later. If the car is lifted, or when viewed from a garage pit, the gearbox is simply impossible not to notice.

Signs and malfunctions of the classic rear axle gearbox

Replacing a gearbox with your own hands is a labor-intensive process, which includes not only the purchase of a new unit (quite expensive), but also time costs. Therefore, before you start, you need to make sure that the gearbox is faulty. You can define the signs like this:

gradually accelerating the car, listen carefully and remember at what moment the noise appears;
while driving, start engine braking (remove your foot from the gas pedal at speed), at this time listen to the gearbox and note the moment the noise appears;
accelerate the "seven" to hundreds, switch to neutral and turn off the engine - listen to how the gearbox behaves while coasting.

“If the bridge is noisy both in neutral and at speeds, the gearbox has nothing to do with it. If the hum occurs only at speed (regardless of the number), repairs, or, as a last resort, replacement of the gearbox are inevitable.”

When the signs are identified, it is necessary to carry out another check:

park the car, secure the front wheels with shoes;
jack up the rear so that the bridge hangs over (it is necessary that the wheels come off the surface);
start the engine and accelerate the “seven” to the point at which noise occurs, while the wheels should spin without load.

If the noise has not changed, then the gearbox is clearly in good working order and it is not the cause of the trouble. Here other drive units are checked. Well, if there is no noise when driving without a load, then we are talking about worn gears of the gearbox, which make noise only when driving with a load.

Signs of a malfunction of the rear axle gearbox of the VAZ 2107

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 rear axle gearbox.
Release the gas and start braking with the engine. While the speed is decreasing, you should also note the moments when noises appear and disappear.
Accelerate the car to approximately 100 km/h and, switching to neutral, turn off the engine. While the car is coasting, note the presence and disappearance of noise.

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

If the noise remains the same when operating without load as under load, the problem is not in the gearbox. Other rear-wheel drive components should be checked.

Defects in the gearbox

Increased play in the RZM can be formed due to wear of the differential pinion pin - if you grab the driveshaft and rotate it clockwise and counterclockwise, this play can be felt. Also, increased clearance can be formed due to wear of the splines inside the differential housing itself.

If the gaps in the main pair of gearboxes are not adjusted, a characteristic noise occurs when the car moves:

when the load increases (sharp acceleration), a characteristic howl is heard in the bridge;
When I let off the gas the noise goes away.

Reasons for failure of the VAZ 2107 gearbox

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

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

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

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

The next procedure is as follows:

Adjusting and repairing the gearbox requires some skills and careful adherence to technology. It is also necessary to have pullers, stands and special tools. If the above is not the case, you should entrust the work to professionals.

Disassembling the gearbox is performed in the following sequence:

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

The inner rings with the separator are removed using a hammer and drift. You need to knock out the rings by lightly tapping them in different places. If you hit only one place, you won’t be able to pull out the ring.

The main pair is available in several variations and determines the gear ratio. The higher the gear ratio, the greater the traction; the lower, the higher the maximum speed of the machine. There are three standard versions of the main pair, used on different VAZ models.

Reference: the VAZ 2102 axle had the maximum gear ratio (4.44). After this model was discontinued, finding pairs with this ratio became problematic, but as practice shows, the best option is installation on a VAZ 2107 with a 1.5-1 engine ,6 gearboxes with 2103 (4.1 gear ratio). When choosing this gearbox in conjunction with a five-speed gearbox, traction and speed are maintained.

How often should the pads be changed?

The need to replace this part on a VAZ 2107 depends on a large number of factors, including:

regularity of maintenance;
general condition of the brake mechanisms and the system as a whole;
driving style;
manufacturer, etc.

These criteria are quite sufficient. In addition to this, you can find out about the need to replace the pads by the behavior of the brake system. For example, if during a stop, extraneous sounds are observed - grinding, creaking, and so on. Does it require significant force to slow down? It's time to worry about buying new pads.

If the machine is equipped with low-quality parts, wear will be quite rapid. Pads from Ferodo, Nippon, ATE - recognized quality and durability.

Using reliable products, replacement of this part will be required once every 25 thousand km.

It is important to note that installing the right or left block separately is strictly prohibited. These works are performed in pairs on each axis.

How to check a shock absorber

To make sure it works, you will need to do the following:

it is clamped in a vertical position;
raise to the maximum;
quickly lowered.

This procedure must be repeated several times.

The following signs indicate failure of this part:

presence of sounds during the above procedure;
jamming;
failure.

This shock absorber is replaced with a new one. However, before doing this, it is better to make sure that any individual element is not damaged. If this is the case, then only what is broken is replaced.

The procedure is as follows:

the rod is pulled out to the maximum;
the nut is unscrewed;
take out the fixing elements and the rod itself;
remove the working cylinder;
every detail is inspected.

If defects are found, they are replaced. Assembly is carried out in reverse order.

After installing the compression valve, you need to make sure that its discs move smoothly. Jamming is not acceptable.

Finally, it’s worth informing us that on average in Russia a new rack will cost approximately 3 thousand rubles. As you can see, the price is quite serious, and therefore it makes sense to treat the car more carefully and regularly care for it.

To fully familiarize yourself with the process, we recommend watching the video below:

Opening hours: Mon-Sat (from 8-00 to 20-00) Sunday until 18-00

Service station: Directions Director

https://youtube.com/watch?v=2MJdj1Y3HME

Sources

https://ladaautos.ru/vaz-2109/samostoyatelnaya-zamena-zadnix-stoek-vaz-2109.html
https://remontavto-tolyatti.ru/sto-zapchasti-avtomobiley/prodazha/468/remont-hodovoy-chasti-zamena-zadnih-amortizatorov-vaz.html

Dependence of driving characteristics on dimensions and weight

A classic method of improving the traction and dynamic characteristics of a vehicle is to properly distribute the weight of both the vehicle itself and the luggage it carries. Speed tests have shown that rear-wheel drive cars (which is the VAZ 2106) when accelerating, shift part of the weight from the center of the car and the front axle to the rear. The latter leads to a greater load on the rear side of the chassis, which is an auxiliary effect when driving. This is due to an increase in the contact patch and an increase in the coefficient of adhesion of the tire to the road surface.

The standard dimensions and weight of the vehicle allow you to transport up to 150 kilograms of luggage or any other cargo. Weight up to 400 kilograms does not affect the dynamic performance of the car in any way. Achieving a maximum speed of 152 km/h is possible when fully loaded with luggage, driver and passengers. With the previous parameters, reaching the speed mark of 100 km/h is achieved in 17.2 seconds. If you have luggage weighing up to 150 kilograms, the amount of gasoline consumed per 100 kilometers at a speed of 90 km/h is ten liters and one hundred grams.

But no matter how much you reduce the weight of a vehicle, it will not be possible to increase power. Reducing the weight of the VAZ 2106 car and modernizing its body components will help improve dynamic characteristics. This can be achieved without changing the design of the body, power or traction units in the following ways.

Do not drive a car with a full tank of fuel, do not add fluid to the windshield washer reservoir. The weight of a full fuel tank is more than eighty kilograms, and the windshield washer tank weighs up to ten kilograms.
Forged wheels lead to the loss of 10–20 extra pounds.
Upgrading the suspension, replacing steel levers with aluminum ones, the overall dimensions of which are suitable, will reduce the weight by another couple of kilograms.
How much will replacing the muffler cost? About 25–30 kilograms.
Modernization of non-load-bearing streamlined parts of the car body will help to improve the aerodynamic properties of the car, provided that the dimensions of the car remain unchanged.

The above methods for making a car lighter are not the only or unique ones. How many are there? Yes, a lot. However, the fact that the VAZ 2106 weighs less affects not so much the speed indicators as the braking characteristics, handling, etc.