Rear suspension the car's running gear, dependent, consists of a guide device and springs and shock absorbers, the value of which is damping of body vibrations. In the following we will show and describe and number the main parts of the rear suspension in more detail.
- 1. Spacer sleeve.
- 2. Rubber bushing.
- 3. The lower longitudinal bar connects the rear axle beam with the car body.
- 4. Lower insulating spring gasket.
- 5. Lower support spring cup.
- 6. Compression buffer undercarriage, installed inside the spring, and fastened in the holes of the upper supports with a mushroom lock.
- 7. Mounting bolt of the longitudinal top bar.
- 8. Mounting bracket for the upper longitudinal bar.
- 9. Spring.
- 10. Top spring cup.
- 11. Top insulating spring pad.
- 12. Support spring cup.
- 13. Link rod of the rear brake pressure regulator drive.
- 14. The bushing of the shock absorber eyelet is rubber.
- 15. Shock absorber mounting bracket.
- 16. Compression travel buffer is optional, bolted to the underbody.
- 17. Upper longitudinal bar.
- 18. Mounting bracket for the lower longitudinal bar.
- 19. Bracket securing the transverse rod to the body.
- 20. Rear brake pressure regulator.
- 21. Shock absorber
- 22. The bar is transverse, keeps the body from lateral displacement.
- 23. Lever of the drive of the pressure regulator.
- 24. Support arm sleeve holder.
- 25. Support arm bushing.
- 26. Washer.
- 27. The sleeve is remote.
Multi-link, independent. It is a rather vulnerable element in the Focuses, as it contains 8 levers and 14 silent blocks.
If over time your suspension starts to rumble, a slight wobbling of the stern appears when driving, then this article is for you.
Figure: Screenshot from the program for the selection of spare parts, suspension Ford Focus 1 and 2. it shows all the main arms of the rear suspension.The diagram shows:
5A638 - trailing arm silent block, 5500A bone lever, 5500b - sickle arm, 5K652 - large transverse arm, HB1 - mounting bolts (8 pcs.), HB3 - silent block bolt (4 pcs.)
The 5500b is a crescent-shaped lever; on a sedan and a station wagon, they differ in shape (in this diagram, a lever for a station wagon is drawn).
The arrows indicate the breakup bolt, nut and washer, which must be changed each time the lever is removed (if this is not done, then it will not be possible to set desired angles installation of the rear wheels).
5A638 - silent block of the rear trailing arm, as a rule, requires replacement along with the levers. It is fastened with screws HB3, which are supplied only in the original (with variable thread).
5500A is a small wishbone, the so-called "bone". These levers take a heavy load, I recommend installing the original, Febi, Lemforder or Meyle.
Drawing - crescent rear suspension Ford Focus 1, 2 (sedan and hatchback)
Sickles on the station wagon
On cars in the station wagon body, crescent levers of a different shape were installed from the factory, this was done due to the fact that the load on the trunk is more in the station wagon, and at the maximum load of the trunk in large pits there could be blows of the standard sickle-shaped lever on the body. The crescent levers of the station wagon are reminiscent of the shape of a banana. When buying levers for a station wagon, you can buy standard levers from a sedan and a hatchback, because "banana" levers are more expensive and there is less choice, these are either Chinese levers or expensive original ones. Standard "sickle" levers are cheaper and have no good counterparts. As practice shows, messages from forums, etc., standard "sickles" from a sedan are easily installed on a station wagon, and this does not lead to any shock or wear.
Picture - Crescent lever of the station wagon "banana"
On Ford Focus 2 cars, two rear suspension options are installed.
The first suspension option(straight levers) is the same with the Ford Focus 1 suspension, has straight spring levers. Straight levers are original and non-original.
Drawing- Straight levers (OE number Ford: 1357317)
Figure Straight levers on the car Focus 2
On the "straight" levers is a stabilizer post "hairpin" (1719542).
The second version of the suspension is distinguished by spring-loaded levers - they are "bent" there.According to statistics, such levers are found in 1 case out of 10 cars. Levers are only original. You can put levers from Mazda 3, they are exactly the same, they even have a FoMOCo stamp.
Also, the suspension with "bent levers" has a different type of stabilizer bar. In order to determine what type of suspension is installed on your car, it is not enough to look at the VIN number in the catalog - there, in most cases, you cannot see what kind of rear suspension arms you have.
To determine which levers (the first or second option) are on your car, you need to approach the car from the side exhaust pipe, look under the bumper and look at under the spring arm on which the spring is installed. If it is straight, then you have the appropriate suspension and stabilizer bar - a hairpin. If the lever is "curved" then the stabilizer strut is L-shaped.
Figure - Rear transverse "bent" lever ( original number Ford: 1548460)
Features of replacing rear suspension arms.
In total, the rear suspension Ford has 6 levers that are replaced during repairs - 2 "bones", 2 "Sickles" and 2 "under spring" ones. Most often they wear out at the same time, backlash appears in each of them. Then they all change together, but there are exceptions, you can change separately "bones" or "sickles" for example.
Ford Focus rear suspension malfunction signs.
Symptoms indicating a malfunction of the rear suspension are firstly extraneous sounds, secondly, this is the yawing of the rear of the car when driving, and of course, when viewed at a service station, you can see the state of the silent blocks and the suspension as a whole.
Non-original parts.
If you find out what you have, then you can purchase a set of rear suspension Focus on reasonable price... If the lever is "bent" then you can purchase such a lever only original (bones and sickles can be bought while not original).
A complete set of rear suspension Ford Focus is produced by several firms. Mapco, Meyle, Ruville, Teknorot and others, rarely found in St. Petersburg from suppliers.
Mapco (China Germany, budget option, there are two options - with a set of bolts part number 53612/1 and without a set of bolts 53612).
Drawing - a set of levers for Ford Focus, Mapco 53612/1
Drawing - .
The second company is Meyle, made in Germany, the quality is good.
There is a Ruville kit (935259S). It is more expensive, but in addition to levers and bolts, it includes two additional silent blocks of the fist ("butterflies"), which also always change.
Drawing - rear suspension kit Ford Ruville 935259S
(note that the kit includes "butterfly" silent blocks and shock absorber bumpers)
The suspension of cars with front-wheel drive is mainly semi-independent on rear wheels on an elastic "P" -shaped beam.
The rear device is shown in the figure.
Simplicity of construction;
High stiffness in the transverse direction;
Low weight;
The ability to change the characteristics by changing the geometry of the cross-section of the beam.
This system also has disadvantages:
Sub-optimal camber change;
Special requirements for the geometry of the vehicle underbody at the attachment point.
Rear beam
Independent rear suspension device
To improve vehicle handling and increase comfort, an independent rear on racks with longitudinal and wishbones... Its device is shown in the figure.
Independent suspension
This design has the following advantages:
Relative simplicity of design;
Low weight and cost;
Improved camber and toe characteristics during operation.
Along with the advantages, such a scheme has disadvantages:
Limited limits of initial camber setting;
Increased noise when processing road irregularities due to the location of the strut supports directly in the body.
Multi-link rear suspension
On cars of the middle and higher classes, which imply a high level of driving comfort and improved handling, a multi-link rear is used. One of the variants of this design is shown in the figure.
Multi-link suspension
It has the following advantages:
The ability to ensure optimal wheel alignment angles during operation;
Possibility to improve the comfort of movement;
Reduced noise and vibration transmitted to the body.
The disadvantages include:
High manufacturing cost;
High labor intensity of maintenance and repair.
By using independent multi-link rear suspension, designers can ensure that both camber and toe are optimally adjusted when cornering.
The right combination of the stiffness of the rubber elements can provide the so-called "steering" effect. This term refers to the individual change in toe-in of the rear wheels under the action of centrifugal force, which compensates for the lateral slip of the wheel.
Unfortunately, the development of such a design requires a large amount of development work and, accordingly, significant costs. That is why multi-link suspensions are not widely used in small and medium-sized cars.
»Rear suspension scheme - types and arrangement
Simplicity and rigidity of the rear suspension.
The rear suspension of front-wheel drive foreign cars has recently been increasingly performed dependent, with a torsion beam. This decision is connected, again, with the forced reduction in the cost of cars and the reduction of manufacturers' costs. The rear wheels are rigidly connected to each other by a torsion beam, which works for "twisting-unwinding". Comfort and handling, of course, decrease, but this, again, manifests itself in to a greater extent on bad roads.
Such a suspension is inexpensive to maintain, however, as a rule, its travels are very small, which causes the feeling of a "goat bum" on the potholes. On utility vehicles, instead of springs, springs are often found (for example, on Toyota Caldina), although shock absorbers are not uncommon (on the Nissan Expert). Since the shock absorbers run from full stretch to the bump stop, they wear out quite quickly and also require careful attention. This suspension is softer when the rear of the vehicle is loaded.
I would like this! Multi-link suspension is used on medium and medium-sized vehicles high class with different drive formulas. "Multi-link" is found both in front and behind. In such a suspension, at least four levers are used to secure the wheel hub. This solution provides independent longitudinal and lateral adjustment of the wheel and stability of the camber angles.
In modern designs of multi-link suspensions, along with transverse levers, longitudinal ones are used. Suspension is expensive to manufacture and install, which limits its use on assembly lines for mass and low-cost car models. But on the other hand, the asset of the "multi-link" is a high smoothness of the course, low level noise, better handling, lower wear rate of elements. Solution options multi-link suspension there is a great variety, in contrast to the previous schemes.
Our experts are unanimous: in order for the suspension of any type not to let down the car owner, you need an eye and an eye behind it.
There are no elements in it, the failure of which would not provoke the rapid degradation of other nodes.
“Our roads deal with the suspension elements pretty quickly, not sparing any“ our own ”( domestic cars), nor "strangers" (foreign cars). Car owners must clearly understand that a defective suspension is not just a decrease in comfort, but also a fatal danger. A barely noticeable backlash in the steering tip is extra meters of delay in the reaction of the car during a sharp maneuver, especially at high speed.
The "killed" rack can turn into a hit into a ditch when hitting an obstacle. Defective rear shock absorbers lead to body buildup, and "your back" (that is, the back of your car) will sooner or later find itself in the oncoming lane when you brake sharply. The suspension begins to "die" from the struts, then increased efforts are applied to the supports, silent blocks, levers.
It is very important to check the condition of the undercarriage at least twice a year. Winter in our country has a very bad effect on rubber and shock absorbers, and the metal becomes fragile in such cold weather. Excessive demand for suspension maintenance is observed, as a rule, in the spring and autumn, although it is better to eliminate problems in a dry season, when there is not much water on the streets that penetrates all the cracks of the chassis assemblies.
Rebuilding suspension elements such as ball joints, struts and shock absorbers is justified. Indeed, 90–95% of a Japanese shock absorber does not wear out, which means it can be successfully used further. The same is with ball joints. With a high-quality restoration, the product receives new resource, sometimes exceeding the initial one - the factory one. Moreover, the unit becomes adapted to our operating conditions. But there are also exceptions - one-tube shock absorbers are practically not subject to restoration ”.
Seasonality in demand for rear suspension repair.
A surge in calls is registered in the summer. However, the suspension should be checked at least once a year and should be done after winter. The front suspension wears out faster than the rear suspension - it is heavier and harder due to the steering. A separate repair of the front or rear suspension is possible, but it is more expedient to do everything in a complex.
Most often it is necessary to replace silent blocks, which is directly related to the quality of the roads. A quality rack can last up to three years with careful handling. If you drive according to the principle " more speed - fewer holes, then even the original rack can be "killed" in three months. By the way, original products are in great demand, rather than "duplicate" ones.
The service life of a "duplicate" strut or shock absorber is usually 1–1, 5 years, while the original may come out in all three. It turns out that the overpayment for the original pays off in this case. With regard to silent blocks ... Definitely, only the original should be installed, since the difference in the price of the original and the "duplicate" is in most cases insignificant. The suspension of foreign cars is better and faster to repair than the suspension domestic cars... If we take the annual mileage, then in the end it will be cheaper to service the chassis of a foreign car, despite the fact that the parts for domestic cars cheaper.
As for the restoration of ball assemblies, struts and shock absorbers, everything here very much depends on the skill level of the craftsmen and the equipment where the restoration is carried out. If a client brings a restored ball joint, and we see that the work has been done with high quality, then we will install the unit on the car without objection. If, for example, spherical bearing or the rack is exclusive and it is impossible to buy a replacement or pick up an analogue, restoration often becomes the only option.
Car tires have a significant effect on the rate of suspension wear. Tires that are too stiff absorb less shock to the suspension elements, and they wear out faster. The same can be said for overly low profile tires. The use of such tires on our roads guarantees direct impacts on the rim, and the need to tweak or change the rim may be added to the suspension repair. The work of the suspension does not significantly depend on which disc is installed on the car - stamped, forged or cast. If only the dimensions were within tolerances.
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Citroen will refuse hydropneumatic suspension
With the continuous development of technology, modern cars are becoming more sophisticated every year. This statement applies to all systems and mechanisms without exception, including the vehicle's suspension. The suspensions of cars produced today are a rather complex device that combines hundreds of parts.
The elements of many car suspensions are controlled by a computer ( electronic way), which records all the readings of the sensors and, if necessary, is able to instantly change the characteristics of the car. The evolution of the suspension, to a large extent, has contributed to the fact that you and I can ride more comfortable and safe carshowever, the main tasks that the car suspension performed and is still performing have remained unchanged since the days of carriages and horse-drawn carriages. Let's find out what exactly is the merit of these mechanisms, and what role the rear suspension plays in the life of the vehicle.
1. Purpose of the rear suspension
An automobile suspension is a device that provides elastic adhesion of the wheels of a car to the supporting structure of the body. In addition, the suspension adjusts the position of the vehicle body while driving and helps to reduce the load on the wheels. In modern automotive world there is a wide choice different types car suspensions, the most popular of which are spring, pneumatic, spring and
This element takes part in all processes that occur between road surface and by car. Therefore, all design changes and improvements to the suspension device were aimed at improving certain performance, which primarily include:
Comfortable travel conditions. Imagine driving to a nearby town in a carriage with wooden wheels, what is your feeling? It is clear that to overcome several hundred kilometers for modern car much more pleasant, even in spite of the quality of the current roads, which in some places, it seems, have not changed since the days of those horse carriages. It is thanks to the functioning of the suspension that it became possible to achieve optimal smoothness of movement, eliminate unnecessary body vibrations and shocks from road irregularities.
The level of vehicle handling, characterized by the correct reaction of the wheels to the "commands" of the steering wheel. But the ability to change direction (turn) also appeared thanks to the suspension (more specifically, the front one). Particular relevance, accuracy and ease of maneuvering acquired with the beginning of the growth of speeds: the higher the speed becomes, the more the behavior of the vehicle changes when turning the steering wheel.
Vehicle passenger safety. The design includes some of the most actively moving parts of the machine, which means that the safety of movement directly depends on its characteristics.
Basically, the suspension of front-wheel drive cars is semi-independent and is located on the rear wheels, located on an elastic "U" -shaped beam. That is, it consists of two trailing arms, one of the ends of which is fixed to the body, and the wheels are placed on the other. The longitudinal levers are interconnected by a transverse beam, which makes the suspension look like a letter "P". This type of rear suspension has the most optimal wheel kinematics, moreover, it is compact and simple, however, its design does not allow the transmission of torque to rear wheels, therefore, a semi-independent rear suspension is used on most front-wheel drive vehicles.
It has the following advantages:
- simple design;
High level of lateral rigidity;
Small mass;
The ability to change characteristics due to changes in the cross-section of the beam.
However, like any system, the semi-independent suspension also has some drawbacks, which are expressed in non-optimal camber changes and special requirements for the geometric parameters of the underbody at the attachment points.
As a rule, the rear suspension is always simpler than the front. On the bulk of cars, the rear wheels are not able to change the steering angle, which means that the structural side of the rear suspension should only provide for vertical wheel movement.
However, the condition of the rear suspension directly affects the vehicle's driving safety and driving comfort. Therefore, it is worth remembering that the regular diagnosis of the rear suspension and the timely repair of its parts depends on whether you can avoid more serious problems in the future. Sometimes, it even concerns the safety of the lives of the driver and passengers.
In addition to the semi-independent suspension, inexpensive models cars, dependent rear suspension is often used. In this version, the wheels are connected to each other by means of a rear axle beam, which, in turn, is attached to car body longitudinal levers. If an increased load is placed on the rear of a car with this type of suspension, slight disturbances in ride quality and slight vibrations may occur. This is considered the main disadvantage of the dependent rear suspension.
2. Types of rear suspension and the principle of their work
The rear suspension of cars has a fairly wide range of variations, but now we will consider only the most common and well-known types. Pendant "De Dion". This kind The rear suspension was invented over a century ago, however, it is successfully used in our time. In cases where, due to financial or layout considerations, engineers have to abandon independent suspensions, the old de Dion system, comes in handy. Its design is as follows: crankcase main gear is attached to the frame cross member or to the body, and the wheel drive is carried out using semi-axles placed on hinges.The wheels are connected to each other using a beam.
Technically, the suspension is considered dependent, but thanks to the massive final drive mount (attached separately from the axle), the unsprung weight is significantly reduced. Over time, the continuous desire of engineers to relieve rear axle from unnecessary load, led to an improvement in the design, and in our time we can observe both its dependent version and its independent one. So, for example, in a car Mercedes R-class, engineers were able to successfully combine the advantages of various schemes: the main gear housing was fixed on a stretcher; wheels - suspended on five levers and driven by swinging axle shafts; and the role of elastic elements, in this design, is played by pneumatic struts.
The dependent suspension is the same age as the entire automotive industry, which, together with it, went through various stages of improvement and has successfully reached our days. However, in a world of rapid development modern technologies, it becomes more and more only a part of history every year. The fact is that bridges that rigidly connect the wheels are used today only on classic SUVs, which include cars such as UAZ, Jeep or Nissan patrol... Even more rarely, they can be found on passenger cars. domestic productiondeveloped more than half a century ago (Volga or Zhiguli).
The main disadvantage of using this type of suspension is obvious: Based on the design, the movement of one wheel is transferred to the other, as a result of which resonant oscillations of the wheels appear in the transverse plane (the so-called "Shimmy" effect), which not only harms comfort, but also significantly affects the vehicle's handling.
Hydropneumatic suspension.The rear version of such a device is similar to the front one and denotes the type of automobile suspension, in the operation of which elastic elements of the hydropneumatic type are used. The ancestor of such a system was Citroen, who first used it on their cars back in 1954. The result of her further developments are active pendants Hydractive, used by the French company to this day. The first generation (Hydractive 1) appeared in 1989. The principle of operation and design of such devices is as follows: when hydropneumatic cylinders pump fluid into elastic elements (spheres), the hydroelectronic unit controls its amount and pressure.
A shock-absorbing valve is located between the cylinders and the elastic elements, through which, when body vibrations occur, a liquid passes, contributing to their attenuation. In soft mode, all hydropneumatic elastic elements are combined with each other, and the gas volume is at the maximum level. The pressure in the spheres is maintained within the required indicators and the rolls of the car (its deviations from the vertical position when driving, most often caused by road irregularities) are compensated.
When it becomes necessary to activate the hard suspension mode, the voltage is supplied by the control system automatically, after which the front suspension struts, cylinders and additional elastic elements (located on the stiffness regulators), in relation to each other, are in an isolated position. As the vehicle turns, the stiffness of an individual sphere may change, while at straight motion, the changes affect the entire system.
Multi-link suspension. The first production car with multi-link suspension saw the world in 1961 and it was the Jaguar E-type. Over time, they decided to consolidate the obtained success by applying of this type and on the front axle of the vehicle (for example, separate audi models). The use of a multi-link suspension provides the car with incredible smoothness, excellent handling, and at the same time contributes to noise reduction.
Since the 1980s, the company's engineers Mercedes benz, instead of a pair of double ones, they began to use five separate levers on their cars: two of them hold the wheel, and the other three provide it with the necessary position in the vertical and horizontal planes. Compared to the simpler double wishbone suspension, the multi-link option is just a godsend for the most successful layout of components and assemblies. Moreover, having the ability to change the size and shape of the levers, it is possible to set the required characteristics of the suspension much more accurately, and thanks to elastokinematics (the laws of kinematics of any suspension, which includes elastic elements), the rear suspension also has a steering effect when cornering.
As a rule, when evaluating the suspension of a vehicle, most motorists, first of all, pay attention to its properties such as the level of handling, comfort, and stability (depending on priorities, the sequence may be different). Therefore, they absolutely do not care what type of suspension is installed on their car and what design it has, the main thing is that it simply meets all the necessary requirements.
In principle, it is correct, because the choice of the type of suspension, the calculation of its geometric parameters and the technical capabilities of individual components is the task of engineers. During development and design, the vehicle goes through a lot of all kinds of calculations, tests and tests, which means the suspension standard car already has optimal consumer characteristics that satisfy the requirements of most customers.
3. Stabilizer torsion type
Modern cars can be equipped with one of two main types of stabilizers - lever or torsion bar. Lever stabilizers(often called " jet thrust») Look like a hollow pipe, at the ends of which there are fasteners with silent blocks (they are rubber-metal hinges). They are installed between the knuckle mounts on one side and seat on the body on the other. Due to the rigid fixation and springs, the installation of the stabilizer allows you to create a kind of triangle, the sides of which are the shock absorber (spring), the bridge (beam) and, accordingly, the stabilizer itself.
The torsion bar acts as the main part of the vehicle suspension, connecting the wheels with a torsion element. Today, many car owners consider the torsion bar an almost indispensable element. different types pendants passenger cars... It can be mounted on both front and rear axles. vehicleHowever, on cars where a beam acts as a rear suspension, the stabilizer is not used, and the suspension itself is engaged in performing its functions.
FROM technical side Question, the stabilizer is a rod with a circular cross-section, shaped like the letter "P". Usually, it is made of well-finished spring steel and is placed horizontally (across) under the body. The part is attached to the body in two places, and rubber bushings are used to fix it, which facilitate its rotation.
As a rule, the shape of the torsion stabilizer takes into account the placement of all automotive units located under the underbody of the body. ... When the distance between the underbody and the lower part of the suspension changes on one side of the car, the placement of the stabilizer mounts is slightly displaced, which causes the torsion bar to bend. The more significant the difference in height, the stronger is the resistance of the torsion bar, due to which the stabilizing effect is smoother (in comparison with the lever stabilizer). Therefore, most often, it is installed on the front suspension.
