In detail: do-it-yourself repair of the front suspension Lada Largus from a real master for the site my.housecope.com.
Independent front suspension with telescopic hydraulic shock-absorber struts and helical coil springs.
The front suspension includes stamped lower wishbones and an anti-roll bar mounted to the front suspension subframe.
The front suspension subframe is stamped-welded, box-section, fixed in the front with two bolts to the side members of the engine compartment, in the rear with two bolts to the load-bearing elements of the bulkhead.
Front suspension: 1 - front suspension arm; 2 - stretcher; 3 - bolts of the suspension arm to the subframe; 4 - bar of the anti-roll bar; 5 - bracket for fastening the stabilizer bar; 6 - shock absorber strut and shock absorber spring; 7 - steering fist; 8 - bolt of fastening of the antiroll bar; 9 - pinch bolt connecting the steering knuckle and ball bearing pin; 10 - ball bearing; 11- rear arm silentblock (front silentblock is not visible);
General view of the McPherson front suspension assembly: 1 - suspension subframe; 2 - right and left levers of the front suspension; 3 - steering knuckle with hub and bearing; 4 - shock absorber; 5 - anti-roll bar
Stretcher: 1 - attachment points of the subframe to the front of the body; 2 - places for attaching the front suspension arm to the subframe; 3 - the places of the rear attachment of the subframe and the anti-roll bar; 4 - bracket for attaching a rubber cushion of the exhaust system suspension; 5 - bracket for fixing the rear support of the power unit.
Video (click to play).
Front suspension arm: 1 - lever; 2 - ball joint boot; 3 - ball bearing; 4 - silent blocks of the suspension arm (front and rear)
Anti-roll bar: 1 - nut; 2 - lower rubber bushing; 3 - rubber-metal bushing; 4 - plastic washer; 5 - upper rubber bushing; 6 - screw; 7 - bar of the anti-roll bar; 8 - bar fastening bracket; 9 - rubber cushion of the stabilizer
Front suspension shock absorber: 1 - amortization rack; 2 - shock absorber spring; 3 - compression buffer with anther; 4 - nut for fastening the shock absorber to the body; 5 - support washer; 6 - nut for fastening the upper support; 7 - the upper support of the shock absorber; 8 - bearing of the upper support; 9 - upper persistent spring cup
About modern car suspensions
The suspension connects the body to the wheels, absorbs the forces acting on the moving vehicle and dampens vibrations. Suspension settings directly affect vehicle handling.
In the design of the suspension, four groups of parts are conventionally distinguished. Conditionally, because in different schemes, some elements can perform the functions of two groups, and sometimes even three.
The first group is elastic parts that perceive the effect of forces transmitted from contact with the road surface (springs, springs, torsion bars or hydraulic pneumatic elements). The second group consists of directing rods, transmitting lateral and longitudinal forces and their moments, as well as connecting the body with other suspension elements, transmission and wheels. The third group is vibration damping elements (shock absorbers or shock absorber struts). The fourth is the fastening elements of the suspensions.
Also, suspensions are dependent, independent and semi-independent.
Actually, the first variants of the suspension design were inherited by the car from the cart.The oldest of them is a spring, it was used by the Romans in the first century BC. It is still widely used in commercial vehicles and SUVs today. In the production of modern springs, advanced materials are used, for example, instead of metal, it can be reinforced plastic.
On front-wheel drive vehicles, McPherson struts are most commonly used in the front suspension design. In fact, this is a shock absorber and spring assembly. From below it is attached to the steering knuckle, from above to the roof mudguard. Also, this scheme includes one or two wishbones. The main advantages of the McPherson suspension are compactness and ease of installation, which is important both for manufacturability of production and for ease of repair. On some cars, McPherson struts are also used in the rear suspension.
Also on modern passenger cars, a double-wishbone front suspension design is widespread. As elastic parts in such a scheme, springs, torsion bars, pneumatic elements or hydropneumatic devices are used.
Multi-link suspension - this is the name of the structure, which includes four or more levers, it is used on both the front and rear axles. This suspension provides better handling and was initially used primarily in premium cars. Now it can be found on mass segment cars. The main drawback of this design is one - the high cost and complexity of repair, since many parts and fasteners have to be replaced.
In mass segment vehicles, the rear suspension design most often uses a torsion beam, also called a torsion beam. This type of suspension - semi-independent, since the wheels can turn at a small angle, as a result of elastic deformation of both the beam itself and the fasteners. Its main advantages - compactness, low cost, manufacturability. But there are also serious drawbacks. The main one is that during long-term operation, fatigue cracks may appear in the beam, which are difficult to diagnose.
In recent years, air suspension systems with integrated regulation have been increasingly used in premium vehicles. They allow you to provide a constant ground clearance regardless of the load of the vehicle, as well as to change the ground clearance depending on the vehicle speed and road conditions. This scheme is most relevant for crossovers and SUVs. In such a design, pnsvmoelmsnty or hydropneumatic devices are used. The suspension is operated by microprocessors. The main disadvantages of such a scheme are the high cost and complexity, both in production and in repair.
On cars of the premium segment, active suspensions have recently become widespread, in which the rigidity of the elements and the ground clearance are adjusted using electric drives. Some sports cars even have active anti-roll bars. In the future, the suspension will be even more integrated into the overall complex of active vehicle safety means.
We check the condition of the running gear and transmission every 15 thousand kilometers. On the parts of the chassis (wheels, suspension arms, anti-roll bar, front suspension subframe, rear suspension beam, shock absorbers and suspension springs) and transmission (front wheel drive shafts) there should be no deformations, cracks or other mechanical damage affecting the shape and strength of parts. By alternately hanging the front and rear wheels (while the car must be securely fixed on the stands), we check the condition of the wheel bearings.
Grasping the wheel in a vertical plane, alternately sharply pull the upper part of the wheel towards ourselves, and the lower part away from ourselves, and vice versa. Make sure there is no backlash (knock). If there is a knock on the front wheel, ask the assistant to press the brake pedal. If the knock disappears, then the hub bearing is faulty, and if the knock remains, then the ball joint is most likely worn out. The bearings of the front and rear wheel hubs are not adjustable and must be replaced if there is any backlash. To check the health of the ball joint, insert a mounting blade between the steering knuckle eyelet (which includes the ball joint pin) and the suspension arm.
Pressing the lever away from the steering knuckle with the mounting blade, we observe the movement of the ball joint housing relative to the steering knuckle eyelet. If there is any backlash in the connection, replace the ball joint.
We check the condition of the protective covers of the ball joints of the front suspension. We replace ball joints with torn or cracked covers. To check the silent block of the front suspension arm ...
... alternately insert the mounting paddle between the subframe and the end of the outer sleeve of the silent block (on one side) and the subframe and the lever head (on the other side of the silent block) ... ... and try to move the lever head along the bolt axis, first in one direction and then in the other direction. If the lever head moves freely, without effort, it means that the silent block of the lever is badly worn or damaged and must be replaced. Tears, cracking and swelling of the rubber bushing of the silent block are unacceptable. Similarly, we check the state of the other silent block of the lever.
We inspect the cushions of the anti-roll bar. If tears, cracks or severe deformation are found in the rubber pads, they must be replaced. Grasping the stabilizer bar next to its attachment point to the arm ...
... swing the bar up and down sharply. If a backlash is found in the connection between the stabilizer bar and the front suspension arm, replace the rubber bushings of the screw securing the bar to the arm. To check the condition of the silent block of the rear axle arm ...
… We insert the mounting blade into a rasp between the body bracket and the end face of the outer sleeve of the hinge and try to move the head of the lever along the axis of the bolt. If at the same time breaks or peeling of the rubber of the hinge are found, then we replace the silent block. Checking the condition of the springs and shock absorbers ...
… And rear suspension. Suspension springs must not be damaged. Tears, cracks and severe deformation of rubber bushings, pads and shock absorbers are unacceptable. Leakage of liquid from shock absorbers is not allowed. Slight "fogging" of the shock absorber at the top of it while maintaining performance is not a malfunction. Alternately rotating and turning the front wheels ...
... inspecting the protective covers of the outer ... … And the internal hinges of the front wheel drives, we check the reliability of their fastening with clamps. Covers that are cracked, torn or have lost their elasticity must be replaced. We check that there is no oil leak from the gearbox through the oil seals of the inner hinges of the wheel drives. If there is a leak, replace the oil seals.
Both the rear and the front suspension of the Lada Largus link the body to the axles or wheelbase. This knot softens the knocks and shocks that occur when driving over uneven road surfaces.
The suspension is, as it were, an intermediate link that connects the car body to the road.
Travel comfort is achieved through the interaction of smoothness-oriented mechanisms, damping unevenness and eliminating unwanted vibrations.
The handling is characterized by an adequate response to all steering commands from the driver. Moreover, the accuracy and ease of maneuvers become important aspects during build-up or speed changes.
The Lada Largus suspensions contain actively moving parts, so the safety of the entire vehicle depends largely on them.
One of the main tasks of this undercarriage element is to ensure smooth movement. When the front wheel hits an uneven road, the body continues to move along the previously traveled trajectory, "damping" all vibrations.
Its design is much more complicated than the rear variation, since it provides the ability to change the position of the front wheels, thereby providing effective control of movement in all directions. This is justified by a number of design features that are subject to additional loads.
It is worth noting that the front of the Lada Largus, like any other car, is heavier than the rear, because there are concentrated weighty power and chassis units. Undoubtedly, this causes a lot of stress, which contributes to its rapid wear. Thus, the condition of the front suspension is directly related to the safety of driving.
As a rule, the rear suspension of the Lada Largus is much simpler than the front one: the wheels of the same name do not need to change the steering angle, and their orientation is concentrated only on vertical movement. But, despite this, the condition of this unit is also associated with the safety of movement and the corresponding level of comfort.
Semi-dependent and dependent varieties are considered in relation to it. In the first case, the suspension consists of two levers fixed between the body and the wheels, which provides optimal kinematics. The dependent suspension is connected by a rear axle beam, which is attached to the body by trailing arms.
The suspension during its operation can cause not only all kinds of sounds in the form of knocks and squeaks, but also direct problems with the steering. In case of suspicious behavior of this part, you should immediately carry out its full diagnosis.
The main reasons for leaving the Lada Largus suspension are associated with uneven roads. For example, the knock on the front suspension of the Lada Largus begins after the car hits a hole or runs into a bump.
In addition, the inexperience of the car owner is not the last circumstance that leads to the repair of the chassis. Belatedly noticing a pothole, the brake pedal is pressed, which only increases the load several times and aggravates the situation.
The problem may lie in the malfunction of the shock absorbers, wear of the ball joints, loosening of the fastening bolts, or lack of lubrication. If worn parts need to be replaced, this should be done immediately. When a suspension malfunction is associated with the fixing force or lack of lubricant, then the situation will be corrected by tightening them and appropriate lubrication.
In case of noise or knocking in the rear suspension, in addition to rubber seals and jet rods, attention should be paid to the condition of the exhaust pipe. A detailed analysis of the entire mechanism allows you to accurately determine the cause of the breakdown and eliminate it in a timely manner.
This is most often due to different tire pressures, incorrect wheel alignment or incorrect bearing play. These problems are solved by checking and adjusting the characteristics to match them for normal operation.
In some cases, it is even required to disassemble the suspension using specialized equipment. For example, if the front suspension arm in the Lada Largus is severely deformed, then the entire axle will need to be changed.
It is worth noting that tire defects can not be noticed immediately, so you should swap the wheels of the front of the car. If the direction of departure changes, then the problem is precisely in the condition of the rubber. When the loss of force of one of the springs is to blame, it will immediately compress, affecting the visual tilt of the machine body.
This situation most often develops during braking or acceleration to maximum speed. A passenger car begins to tilt, and under the influence of road irregularities, it makes oscillatory movements. This is justified by the possible imbalance of the wheels, suspension of the suspension springs or failure of the shock absorbers.
In this case, the anti-roll bar may simply not work during acceleration and braking. Here you should check the condition of all parts and, if they are worn out, replace them by securely tightening the fixing bolts.
Such vertical vibrations are unacceptable, since the chassis and steering perceive them as natural dynamic loads, which ultimately leads to loss of control.
Of course, detailed diagnostic procedures and timely elimination of the causes of the malfunction will allow you to quickly repair the suspension. In this matter, it is better to trust the specialists of service centers, who will help prevent overhaul by replacing some nodes or tightening their fixing connections.
The ball joint Lada Largus is of great importance in the design of the car. It adjusts the angle of inclination of the wheels. Damage to the support becomes a significant problem, because if it falls out on the road, it can cause damage to other elements of the car, and further movement will become impossible.
To a large extent, the operation of a car depends on the choice of spare parts for the suspension. Since the ball joint is responsible for the angle of inclination of the wheels at the moment of movement, the selection of this part must be taken seriously.
Native ball joint from Largus removed during replacement. This code does not beat SKUs.
Consider what options for a ball on Largus are provided by manufacturers:
Original catalog number of the ball joint - 401604793R ... The average cost in the Russian Federation is 4500-5000 rubles .
The catalog of substitutes is presented in the table below. All these parts can be installed on the car without fear of poor quality.
Analogue of the original ball on the Largus from TRW with a circular groove
As you can see from the table, an alternative ball joint can be purchased for about 1,000 rubles. The cost of replacing a part at a car service itself is about 1000-1500 per piece.