SHRUS is a new word for many motorists, since when repairing a car, few people have encountered its repair. This, sometimes incomprehensible word, is nothing more than an abbreviation for the phrase "joint of equal angular velocities." In the common people, it is often called a grenade.
This small part, located in the chassis of the car, performs the most important function, or rather, it transmits torque from the gearbox to the idler wheel. In addition, the part transmits the rotational movements of one axle shaft to another. Most often it is installed together with an independent suspension. Its angle of rotation relative to the axis can be up to seventy degrees. But most often this figure does not exceed twenty degrees.
As a rule, CV joints are installed on cars with front-wheel drive, but sometimes they can be rear-wheel drive cars, for example, new model crossovers. Benefits of using a CV joint on the face:
Kinds
The CV joint was invented a long time ago, according to the most common version, it was invented back in the twenties of the last century by Alfred Rzepp. Therefore, it is not surprising that since then many varieties of this part have appeared:
- cracker - installed exclusively on trucks;
- tripod - usually used as an internal CV joint;
- twin hinge - is used quite rarely due to the complex design;
- ball, or SHRUS Rtseppa - the most common type, which is most often used on the axles of cars.
It was this invention that became revolutionary for the design of passenger cars with front-wheel drive.
SHRUS device
Here you can see a photo of a ball CV joint, thanks to which it will become clearer what this part is in the assembled state. If we talk about its components, then, in fact, there are not so many of them:
- Casing with outer casing.
- Separator.
- Inner rim.
- 6 balls.
- Stop ring.
- Anthers external and internal, they are held by clamps.
If you put together these leavers, then they really look like a kind of grenade.
All these parts are assembled into an outer CV joint and an inner CV joint. The internal one transmits rotational movements to the external mechanism, as a result, the angle of the semi-axis with respect to the axis is changed.
On the video you can see the device itself and its operation:
Causes of breakdowns
Despite the fact that all components for this part are made from high-strength materials and are designed for a long period of operation, they can also be subject to wear, which means that the CV joint will no longer fully perform its functions. When turning the wheels and turning the car, it begins to crunch and creak. If at an early stage these phenomena can still be eliminated, then during long-term operation of the car with a faulty CV joint, this part can completely fail, and its replacement will definitely be a significant investment.
But such costs can be easily prevented by replacing such an insignificant and inexpensive part as an external or internal CV joint boot. Usually the mechanism fails due to leakage of lubricant or the ingress of dirt and water into it. And since the only external protection is the boot, the second reason is the most relevant.
Important! When replacing the anther, you do not need to buy a cheap part, it must be carefully checked for fractures and microcracks, the material must be flexible and resistant to mechanical stress.
Attention! If a clear crunch is heard inside the CV joint, this problem should not be neglected and its internal parts should be checked even when the anther is in perfect condition.
Checking details
When checking the CV joint for wear parts, first of all, you need to pay attention to the condition of the anther, both internal and external. If the parts have obvious cracks, then the mechanism probably contains up to a kilogram of dirt from the roads.
If not only the outer, but also the inner anther is damaged, most of the grease has probably already leaked out. Therefore, you will have to remove the CV joint and fill it with fresh grease, but before that, remove the remnants of the old one along with dirt and water.
Attention! In order to lubricate all the parts with high quality, they must be removed one by one, greased on them, and only after that the mechanism must be assembled in the same sequence.
SHRUS lubrication, as a rule, eliminates the crunch inside the mechanism. Naturally, this procedure should be accompanied by the replacement of anthers in case of damage. And you need to remember that the lubricant can become outdated even in the case when everything is in order with the anthers. When replacing it, all parts of the mechanism must be cleaned and rinsed with gasoline, and only then apply fresh grease to them.
How to determine which CV joint is faulty
There is a strong opinion of experienced drivers that if there is a creak in one of the mechanisms, then the second one will also have to be repaired soon. Therefore, when the outer or inner anther is cracked on only one of the mechanisms, the anthers should be replaced on the second one as well. The same thing will happen to him soon anyway.
But, if at the moment it is necessary to check which of the mechanisms needs to be repaired, then you can completely turn the steering wheel and turn the car in this position of the steering wheel. It will be exactly the CV joint in which the lubricant is outdated or the dirt needs to be cleaned out.
Many are also interested in the question whether the internal or external CV joint is worn out and needs to be repaired. As a rule, this is precisely the external mechanism; quite rarely, the internal hinge wears out and must be replaced.
How interchangeable are the right and left mechanisms
Often there is such a situation that it is not possible to completely replace the grenade, and you can only rearrange this or that part from another car. And here the question arises whether it is possible to replace the inner right CV joint with the inner left CV joint, or vice versa. As a rule, only the outer bowls are interchangeable, but the inner ones have a different thread direction on the shank.
But it all depends on the specific car model. Some of them have the same grenades on both axle shafts, both external and internal.
But the CV joint boot is the same on both sides, so you can safely rearrange it from the right grenade to the left, if this is an emergency.
From all of the above, we conclude that, if desired, you can avoid expensive and complex repairs of the CV joint. It is enough to replace the anthers that protect parts from dirt, water and lubricant leakage. As a result, the SHRUS will serve for decades, fully performing its functions.
Another name is grenade. It came from the shape of the hinge - it is very similar to a grenade.
Since the front wheels, in addition to the transmission of torque, must also turn at different angles and a special hinge was invented in different directions - the CV joint. It was created as a replacement for the inefficient, unreliable driveline. The CV joint must ensure uniform transmission of force, regardless of the angle at which the connected shafts are.
The first version of such hinges was patented in 1923 by Karl Weiss: the ends of the connected shafts were a kind of forks, between the inner surfaces of which there were balls that transmit torque. Subsequently, the patent for Weiss hinges was bought by the American company Bendix and began to produce them under the Bendix-Weiss brand. To this day, such hinges can be found, for example, on 469 UAZ vehicles and the legendary GAZ-66 shishiga. However, the most successful design three years after the invention of Weiss was proposed by Alfred Rzeppa - it was, in fact, the six-ball CV joint familiar to us, capable of operating at angles up to 40 degrees, compact and durable. For the first time, Rzeppa's ball joints appeared on production cars in 1959 - first on the famous Austin / Morris Mini (the hinges were supplied by Hardy Spicer Limited), and soon on the German DKW Junior F11 (Lohr & Bromkamp GmbH). (loadposition user20)
| Ball joint of equal angular speeds, the most common option is the Rceppa CV joint |
This CV joint consists of two fists: an inner one connected to the drive shaft and an outer one connected to the driven shaft. Both fists have six toroidal grooves located in planes passing through the shaft axes. There are balls in the grooves, the position of which is set by the separator interacting with the shafts through the dividing lever. One end of the lever is pressed by a spring to the socket of the inner fist, the other slides in the cylindrical hole of the driven shaft. When the relative position of the shafts changes, the lever tilts and rotates the separator, which, in turn, by changing the position of the balls, ensures their location in the bisector plane. In this hinge, the torque is transmitted through all six balls. The limiting angle between the axes of the shafts is 35-38°. |
| The principle of operation of a ball joint is in the picture at the beginning of the article. Hinge type:  This is what a grenade looks like |
| Cam-disk CV joint - the hinge of the Path. |
| The cam-disk joint of equal angular velocities (Tract's hinge) consists of semi-cylindrical forks that are connected to the driven and driving shafts and cylindrical fists inserted into them. The grooves of the fists include a disk that transmits torque from the drive fork to the driven fork. The maximum value of the angle between the shafts is up to 45°. The large contact surface of the parts, which perceives forces, and the high bearing capacity determine their use on heavy trucks. |
Scheme of the Trakt-type hinge. such hinges are used in trucks and heavy equipment due to their high wear resistance.   |
(loadpositionuser20)
Well, after theory - to practice.
If the CV joint is made with high quality and without birth defects, it will last a long time. In fact, the life of this hinge should be equal to the life of the car itself.
The failure of a grenade can contribute primarily
Rupture of the protective casing (anther). Dirt and sand getting into the lubricant will quickly disable the mechanism.
Aggressive urban driving style. This is for those who like to tear from a place with the steering wheel completely turned out. The CV joint is designed for heavy loads with a normal wheel arrangement. And if the steering wheel is turned, the balls are in extreme positions and frequent jerking from a place with the steering wheel turned can gradually disable the grenade.
Signs of a broken joint.
Clicking when moving, crunching. Especially with the wheel turned out. At speed, it can reach a rumble - this is not like a wheel bearing. How long the car will pass is unknown. The CV joint needs to be changed entirely, it is not repairable. (loadposition user20)
The constant velocity joint, or in the popular "grenade", is an integral part of the transmission of a front-wheel drive car. Its main role is the continuous transmission of rotation from the gearbox to the wheels at different angles. Despite the same principle of operation of all CV joints, they differ in design features for different car models. In addition, different operating conditions cause differences in the design of the external and internal CV joints.
The device of the internal CV joint
The inner CV joint is designed to transmit torque from the transmission to the outer CV joint. It differs from the external one in size (in a big way) and cost, although it consists of the same parts:
- Cases in the form of a bowl with a driven shaft.
- The inner cage is a spherical fist with a drive shaft.
- Separator in the form of a ring with holes to hold the balls.
- metal balls.
The roller version of the hinge is characterized by the presence of a support, which, with the help of three rollers, moves along the tracks cut in the inner part of the body. The balls or rollers are located in the grooves of the housing and are held by a cage, which is connected to the drive shaft by a spline connection. When changing the angle of the drive and driven shafts, the balls move along the grooves, continuously transmitting force.
Symptoms
The work of the SHRUS is always associated with the impact of huge loads. Despite the use of high-strength materials in the design of the assembly, it is sometimes capable of failing. The following reasons contribute to this:
- The use of poor quality materials in the manufacture of assembly parts, the use of counterfeit or defective spare parts.
- Lack of lubricant inside the mechanism or its poor quality.
- Ingress of water or abrasive debris into the mechanism due to damage to the anther.
- Excessive load on the mechanism due to unsatisfactory road surface conditions or aggressive driving style.
- Long-term operation, during which the resource of parts is developed.
A malfunction of the internal CV joint manifests itself in the following symptoms:
- A characteristic crunch when hitting obstacles, pulling away or hard acceleration.
- Jerks and vibration during acceleration.
- Play in the joints of the hinge when the wheel is suspended.
How to check the internal CV joint
The breakdown of any part of the car is associated with a change in its size, physical properties, or the appearance of wear on the rubbing parts. A CV joint is a swivel joint in which the elements of the mechanism are in close contact and are under constant load. Over time, in the places of interaction of parts, a development is formed and the gap increases, which manifests itself in an increase in the characteristic “crunch” during sharp acceleration or overcoming obstacles.
Unlike the outer CV joint, which is easy to check when driving at the maximum angle of rotation, the inner CV joint is rarely in a state of maximum curvature. You can verify the serviceability or breakdown of the assembly when hanging the wheel. To do this, on the lift with the engine running, turn on the first gear so that the wheels rotate slowly. If at the same time a crunch is heard from the faulty part, and when exposed to the shaft, play is felt, then the CV joint is faulty.
What lubricant to use for CV joints
The main tasks of lubricants used in CV joints are friction protection and prevention of corrosion development. Also, the lubricant must be inert with respect to polymer anthers, which prevent moisture and debris from entering the mechanism. Most of the above requirements are met by the following types of lubricants:
1. Lithium. These are viscous yellowish compounds, which at low temperatures acquire an even thicker consistency, hardly spreading on parts. They are able to significantly reduce friction and loads acting on the hinge elements, protect them from moisture and neutralize accidentally ingested dirt. Their only drawback is the ability to dissolve some types of anthers made from organic polymers. One of the representatives of this type of lubricant is the domestic Litol-24, which is replaced after a run of 100 thousand km.
2. Based on molybdenum disulfide. More versatile lubricants that are characterized by increased resistance to corrosion. In their composition, the content of organic acids is reduced, due to which the aggressiveness in relation to polymer products is reduced. Such lubricants are recommended for use in CV joints of cars of any manufacturer. Their main drawback is their sensitivity to moisture ingress in case of anther leakage, due to which the lubricant loses its properties. Domestic manufacturers produce lubricants with molybdenum disulfide under the general name SHRUS-4.
3. Barium grease. Resistant to moisture ingress into the mechanism, successfully resists corrosion, and is also neutral to any polymers from which the anthers are made. Its main disadvantage is poor resistance to low temperatures. Lubrication at the moment, due to the high cost, is not very common. All domestic formulations made using this technology are labeled under the name ShRB-4.
- Graphite lubricants, since they are designed to work in bearings, and when used in a CV joint, its service life will not exceed 25 thousand km.
- Hydrocarbon lubricants, including technical vaseline, as they are destroyed at t o exceeding 45 o C, and lead to failure of the hinge after a short time.
- Consistent compositions made on the basis of calcium and sodium, since they are not able to work in units with high mechanical stress, and will lead to failure of the hinge after a run of 15-30 thousand km.
- Compositions made on the basis of zinc or iron.
When changing the lubricant of the hinge, they are guided by the operating instructions for the car and the lubricant itself. Its planned replacement should be carried out every 100 thousand kilometers, as well as when installing a new CV joint or anther.
Replacing the inner CV joint
A faulty internal CV joint is capable of falling apart while driving, depriving the car of mobility. To avoid breakage and unexpected costs, the assembly should be replaced at the first sign of failure. It is desirable to carry out all work at a specialized service station, since the operation requires certain knowledge and skills from the master. But if you have the necessary tool, relevant experience and self-confidence, the motorist is able to do everything on his own in a garage.
Before replacement, prepare the following spare parts:
- The hinge itself.
- Boot with new clamps.
- Lubricant.
- Hub nut.
The replacement procedure is carried out in the following order:
1. The car is jacked up from the side of the CV joint to be replaced or placed on a lift, after which oil is drained from the gearbox.
2. The hub nut is unscrewed and the wheel is removed.
3. Disconnecting the rack from the steering tip and mounting the ball joint.
4. Pulling off the brake disc with the caliper from the slots and moving the structure to the side.
5. Pulling off the inner CV joint from the splines using a metal guide and a hammer.
6. Removing the entire drive to the outside.
7. Removing the anther clamps, the anther itself and the faulty CV joint after clamping the drive in a vise.
8. Laying lubricant in the new CV joint.
9. Mounting the anther and putting the CV joint on the splines.
10. Installation of clamps on the anther.
11. Installation of the assembled drive in the gearbox. When hit in the slots, a characteristic click is heard, after which the drive is hammered into place.
12. Further assembly is carried out in the reverse order.
The described method allows you to replace the inner CV joint of all VAZ models: 2101, 2102, 2103, 2104, 2105, 2106, 2107, 2108, 2109, 21099, 2110, 2111, 2112, 2113, 2114, Niva, Lada Priora, Kalina, Grant, Vesta and most foreign cars.
Cars equipped with front-wheel drive in the 60s were of great interest to engineers and developers of almost all automotive brands. It was believed that this arrangement of bodies makes it possible to get more free space in the cabin. To implement this idea, engineers came up with a mechanism that was quite complicated at that time. It made it possible to ensure the rotation of the front wheels and control them with a more compact design.
How CV joints were created
Since there are several types of angular velocity hinges, it is very difficult to determine exactly which design was the first. But there is an opinion that the knot based on balls, one of the most popular today, was invented in the 20s.
The idea of creating a cam mechanism came up with the French inventor Gregoire. In the early 20s, he received a patent for this invention.
The twin cardan element of equal angular speeds was used mainly in American car models and in the transmission systems of the French Panard-Levassor.
SHRUS - what is it?
CV joints - this is used in the design of independent suspension on front-wheel drive vehicles. This part provides not only rotational energy, but also allows you to control the rotation of the wheels. So, this unit allows you to rotate the drive wheel at an angle of up to 70 degrees. The part is similar to why motorists have nicknamed this hinge.
This design is also found in cars with rear or all-wheel drive, but only in models with independent suspension. In this case, the rear wheels have the ability to move horizontally and vertically. There is an external and internal CV joint. What this detail is, you will soon find out.
How are the angular velocity hinges
Depending on the type of part, the design may be different. However, knowing how the SHRUS works, what kind of element it is, and what its role is, we can say the following. On the one hand, the shaft is connected to and on the other - to the differential. Equal speed joints transfer rotational energy from the motor to the drive wheels through the bearings.
The main components of the product are the clip and the body. Both on the body and on the clip located inside the body, special grooves are cut where the balls are installed. The balls very rigidly connect these components to each other, thereby transmitting rotation.
Thanks to the larger working angle that it has (what it is, you already know), the rotation angle can reach up to 70 degrees. The range of possibilities of the internal hinge allows it to move only 20 degrees. So, both externally and internally, the product uses various types of elements. On the outside, the drive shaft is equipped with ball joints, but on the inside, with tripod joints.
The outer product consists of a cage mounted on a shaft and with grooves along the radius.
The body also has grooves. Balls are installed in them, with the help of which torque is transmitted.
Internal parts may differ in their design depending on the vehicle model and type of suspension.
So, on VAZ models, the grooves are straight, not radial. On Ukrainian ZAZs, the rollers are mounted on three spikes rotating on needle bearings.
In our article, we consider CV joints. You already roughly understand what it is, they work in rather problematic places, because there is always a lot of dirt and dust, so they are equipped with special protection. For this, a protective boot is used - this is a rubber pad that is securely held on the body with clamps.
Advantages and disadvantages
You already know a lot about CV joints (that these are important details in the design of a car). Therefore, it is possible to discuss the main of these products. Among the advantages, one can single out such a property. When transferring energy, there is no loss in power, as is the case when using other mechanisms with a different principle of operation. Also among the advantages - simple replacement and low cost.
Among the shortcomings are the design features of the anther. After all, it performs several functions at once.
This is the protection of the mechanism from dirt and a container for lubrication. The disadvantage of such a detail as a CV joint is that this connection is located where it is impossible to prevent its contact with other objects. So, the anther can be easily torn, and without lubrication, the “grenade” will quickly fail.
Resource or a bit about service
The resource of these parts may depend on a large number of various factors.
Most often, this indicator varies due to structural features, as well as use. And if the car owner cannot change the design, then the operating mode is completely in his power.
Depreciation of the "grenade" in natural conditions is inevitable. But often the capabilities of these nodes are sharply reduced due to the fault of the car owner.
Someone likes to start so that the car skids with the wheels turned out. In this position, the external nodes are in a partially clamped state - these are increased loads. The result is an immediate replacement.
Other car owners love tuning. Sometimes engine power is increased to serious limits, which does not lead to anything good. The greater the torque, the faster the wear.
anthers
Another group of drivers forgets to check the condition of the anthers. There is a factor that has a significant impact on the life of such a part as a CV joint. That this is a lubricant is easy to guess. This means that regular maintenance of the mechanism is necessary. If the tightness of the anther is broken, then this will not only cause pollution of the mechanism, but also a lack of lubrication. All this will not in the best way affect the durability of the node.
To extend the life of the product, you need to regularly monitor the boot, and the driving style should be more relaxed. Then this knot will last a long time.
Often, owners of front-wheel drive cars, in the process of studying the structure of their car, discover interesting names for parts that they have not even heard of before. SHRUS can be attributed to the category of unusual terms. In this material, this concept, the principles of its work, and types will be considered in detail. And the first thing to do within the framework of this topic is to give an explanation of what a CV joint is in a car.
The previously mentioned mysterious name is nothing more than an abbreviation for such a rather big phrase as a constant velocity joint. The main purpose of this device is to transport rotational movements from one axle to another. A prerequisite for this is that these semiaxes are to each other at a certain angle, the value of which undergoes constant changes, but, as a rule, does not exceed the mark of 70.
As for the history of the creation of SHRUS, then, as is the case with many other things invented long ago, there is no absolute opinion. The most common is that in 1927 this device was invented and patented by Alfred Rzepp. By the way, the mechanism is called the “Rceppa” hinge, and the word “grenade” acts as a national driver’s slang.
It should also be noted that the SHRUS can also be found in cars with rear-wheel drive and all-wheel drive design. But here two prerequisites come into play: the presence of a rigid mounting of the gearbox, which is located in the rear of the car, and an independent suspension, which is on the rear wheels.
This mechanism among professional motorists is considered simple. It usually consists of four parts:
- body in the form of a spherical bowl, plus a driven shaft;
- the inner cage, which is a spherical fist, plus a drive shaft;
- a separator, which can be explained as a ring with special holes, designed to hold the balls;
- balls in the amount of six pieces.
This standard set of components of the hinge makes it possible to transfer the rotational movement as smoothly as possible. In addition, every car owner should be aware of the lack of this ability in the universal joint of the axle shafts, although it performs the same function as the CV joint.
As for the principle of operation of the SHRUS, it can be characterized as follows:
- spherical grooves are located in the body, as well as on the inner race, and their number is equal to the number of balls;
- the balls are held by the separator, and they are placed in the space between the fist and the body;
- the balls move with the help of the grooves of the body along the outer diameter, and with the help of the grooves of the fist - along the inner one;
- the force that occurs during the rotation of the drive shaft is transmitted to the cage, then to the driven shaft with the help of a fist and balls that are located in the grooves;
- the balls continue to transfer forces quite freely, moving along the grooves, after the change in the angle between the shafts of the driving and driven types.
To maintain cleanliness, and hence the safety of both the device itself and the car as a whole, it is recommended to cover the CV joint with an anther. Most often, the protective function is conscientiously performed by a rubber pad, which prevents water, dirt and other unnecessary substances from entering the rotating parts of the mechanism.
Like any other device, especially located in a car, the CV joint has certain advantages and disadvantages. As for the first one, we should talk about significantly less power loss compared to the rear-wheel drive type design, light weight and easy replacement. But the disadvantages of this unit are wear in the process of starting off. Also, the CV joint is significantly inferior in power to the bridge.
The process of operation of any “grenade” in a car constantly takes place under heavy loads, therefore, the elements of this device are made of heavy-duty materials for the purpose of slower wear. But this still will not ensure the eternal service of SHRUS. Due to various reasons (aggressive driving, ingress of unnecessary substances in the form of dust, water and dirt), the hinge may stop functioning. To prevent this, you need to know the following points. 
Firstly, the first sign of the occurrence of some malfunctions in the operation of the CV joint is the appearance of an unusual crunch in the process of making turns and sudden accelerations by the car. The first thing to do in this case is to inspect the drive. This process consists in a visual inspection of the anthers for any damage or the presence of lubricant leaking from under them. After that, it is necessary to check the condition of the bearings by swaying them in different directions. An indicator that not everything is in order with this device is a clear feeling of backlash. Therefore, the next step is to replace the inner CV joint.
Hinge types
Different sources offer different classifications of CV joints. But in general, it is possible to distinguish the distribution of species, which car owners will be able to navigate in the future. First of all, it is necessary to select the hinges depending on their location. So, on each drive, an external and internal hinge must be installed.
A more extensive classification of hinges is as follows:
Video “How to lubricate the inner CV joint”
On the record, a motorist shows how to properly lubricate the internal CV joint.
