Which is better, tripod or CV joint? How does a tripoid bearing (inner CV joint) work? When do you need to shoot with a tripod?

A CV joint, or constant velocity joint, is a mechanism that transmits torque from the transmission system to the wheels. In this case, the traction is transmitted to the driving steered wheels without loss of power. The mechanism allows for rotations of up to 70 degrees.

There are several types of CV joints that are used in front-wheel drive cars. Crackers are installed mainly on heavy trucks or buses. Tripod CV joints are used in internal structures due to their axial movement characteristics. Twin universal joints are not particularly popular due to their complex design. Ball CV joints are most common on front-wheel drive vehicles. These are installed on models from AvtoVAZ.

Hinge function and location

A fairly small number of motorists know what these components are and what they are intended for. And even more - on various forums this part has many names.

Automotive mechanics are a rather complicated matter. You have to master it throughout your life and each time in a new way (in the event that you suddenly decide to purchase a new car of a brand you are unfamiliar with). Today we want to help you master the features of another car part - the tripoid bearing. If you were unable to immediately understand which bearing we are talking about, there is no need to worry. We are talking about an internal CV joint (constant velocity joint), which has a special design called “tripoid”. Breakdowns of this part do not occur very often, but it takes a lot of effort to fix it. Below we will try to tell you in as much detail as possible about this slightly intricate bearing and what to do if it fails.

1. What is a tripoid bearing, and where is this car part located?

According to our mini-survey of car enthusiasts, it was found that not everyone knows about the tripoid bearing and the purpose of this part. Moreover, as a result of our travels through the vastness of the Internet, it turned out that this part is called by many names: tripod CV joint, internal CV joint, tripod, and simply “grenade”. But whatever the name, in this situation we are talking about, which we have already introduced you to in previous articles on our blog.

But, as we already mentioned in our little introduction, a tripoid or tripod bearing is a special design of a CV joint, which is most often installed on a car on the drive side (by the way, this is the answer to the question of where the tripod bearing is located). Every car owner also needs to know that this bearing consists of spherical rollers and a fork, which allows for fairly large axial movements, and at the same time provides a nonlinear change in speed at an angle.

What is the role of this part, or rather the whole mechanism? Everyone knows that the movement of car wheels occurs thanks to the drive, which transmits rotation to them. However, if angular velocity joints were not installed on the car, the wheels would stop spinning when turning. And it is precisely the special design of the CV joint that allows you to change the angle between the axle shafts and continue to move the car regardless of the position of its wheels.

The CV joint was first invented back in 1927. It was patented by a mechanic named Alfred Rzepp, after whom it was called for a very long time. Today, the name “grenade” is more common among car enthusiasts. This part is a mandatory attribute of every front-wheel drive car, although it is also often found on rear- and all-wheel drive cars. In the latter case, this is done in order to make the rear gearbox mount more rigid and the rear wheel suspension more independent.

2. How is a tripoid bearing or the design of a conventional internal CV joint?

When we first encounter malfunctions of a given part, it turns out that we don’t know that much about it. Although the CV joint is quite simple in its design, its placement and the complexity of possible breakdowns force many car owners to turn to specialists at a service station. We all know that this solution is not at all profitable from an economic point of view. Therefore, let's try to figure out the features of its design ourselves.

The CV joint has a very long service life, and under proper operation conditions its service can be very long. By the way, its work is somewhat reminiscent of the work of the knee joint, however, unlike the human body, it is not so complex. The design of the external hinge is almost identical to the internal one, and it consists of only 4 parts:

- the main body of the part, which is made in the form of a spherical bowl with a driven shaft;

Inside there is a clip in the form of a spherical fist with a drive shaft;

A separator made in the form of a ring with special holes that allow you to hold the bearing balls;

Directly the balls themselves, the number of which is usually six.

The only difference between a tripoid or internal CV joint is that it is not a ball bearing, but a needle bearing. At the same time, there are as many as three planes on it, in which the corresponding number of needle bearings are located. That is, the basis of the external hinge is balls, and the basis of the internal hinge is rollers with needle bearings. Regardless of whether the hinge is external or internal, a boot must be installed on top of it to prevent dirt from getting on the part itself and, thereby, ensuring its long service life.

Unlike the usual CV joint with a ball bearing, the tripoid is a more “delicate” part. Even the smallest amount of dirt can immediately cause a breakdown. Even lubricant for needle bearings must be used specifically for them.

Also, the tripoids themselves may differ from each other in the degree of freedom that they transfer to the wheels from. In any case, all the functions of a tripoid bearing are reduced to ensuring a very smooth transmission of rotational motion. As is known, the universal joint of the axle shafts, which is assigned the same function, does not have this ability. Even if one axle shaft rotates evenly, intermittent movements will still be transmitted to the second from the cardan.

3. Tripod bearing malfunctions that every car owner may encounter

At first glance, this part is not that important for the car, but the tripoid is constantly under very heavy loads, and its malfunction completely immobilizes the car. In this regard, tripoids are made from very durable materials that can be used for a longer period of time. But still, for a number of reasons, breakdowns happen, and every driver should be able to react to them correctly.

The very first reason that leads to such a result is related to the aggressive driving style of the car owner. After all, the harder you press on the gas, the greater the load becomes, which is transferred to the drive, and from the drive to our tripoid bearing. The second reason for breakdowns is damage to the dust cover or simply the boot of the internal joint. As a result, a lot of dust and dirt begins to fall on the part, friction inside the mechanism of the part increases, and over time it fails.

It is possible to understand that something is wrong with the operation of the tripoid bearing earlier, before it fails directly while driving. In particular, The first signs of approaching serious troubles that can still be corrected are:

- the presence of vibrations in the movement of the car during its acceleration;

The presence of vibrations even when driving at speed;

A characteristic knocking sound from the side when driving at low engine speeds.

If you observe this with your car, it’s time to drive it into the inspection hole and carefully inspect the CV joints, both internal and external. If there is even minor damage to the boot, driving such a car becomes quite dangerous. Any auto mechanic will advise you to remove the part from the car, disassemble it, wash it, re-lubricate it and put on a new boot. We will tell you how to do this.

4. Repair and replacement of tripoid bearing.

If you determine the presence of a malfunction at the very first stage of its occurrence, you still have a chance to extend the service life of the part without replacing it. If the needle bearings have worn out and crumbled, you will have no options. We just remove the part, wash it and go to the auto parts store so that they can pick up a similar one for you. However, let's talk about everything in order.

How to remove a tripoid from a car?

First of all, you need to prepare: find an inspection hole or overpass for work, a standard set of motorist tools. Depending on whether you are going to repair the inner CV joint or replace it, you will need either lubricant and a new boot, or a new part. Let's get started:

- we drive the car to an elevation so that it is convenient for us to work with the CV joint;

We unscrew the fastening - 6-8 bolts with which the hinge cages are screwed to the differential gears;

We remove the entire CV joint structure from its socket and from the shaft itself.

However, there is one more small nuance: after you have unscrewed the fastening, be sure to turn the steering wheel to a position that will allow you to release the spline joints. Also, it is not always possible to easily and simply remove a part from its socket. Ideally, you should use a special puller for CV joints. But not everyone has it and it’s not so easy to get it, so motorists often use a hammer, a crowbar and their own strength. The main thing is not to overdo it so as not to accidentally damage the part.

There are also certain difficulties in properly removing the joint from the shaft. To do this, you need to unfasten the locking ring and remove the boot clamps, which will also prevent you from removing the part. Unfortunately, on some car models, the hinge may be secured with a solid corkscrew ring that cannot be removed without damage. Manufacturers do this on purpose - you have no choice but to go buy a new part.

Mechanics also advise removing two CV joints at once - internal and external. It is not only more convenient, but also safer. It is not worth repairing parts directly under the car. It is better to get to a workbench or table with good lighting.

We disassemble the tripod itself and carry out its repair. What we do:

1. Remove the large and small clamp from the part.

2. We remove the boot and its inner part.

3. We remove the tripoid itself from the shell.

4. Using a screwdriver, remove the lock washer that secures the tripoid to the axle and remove it.

5. We wash all parts in gasoline to remove not only old grease, but also absolutely all contaminants.

Next, you need to apply new lubricant. We already mentioned that it must be special and ideal for needle bearings. Today it is quite easy to purchase lubricant that is intended directly for tripod CV joints, so you should not have any problems.

First of all, we need the clip from which we took our tripoid (it is also simply called a “glass”). You need to pour about 90 g of lubricant inside it, leaving a little more in a standard bag. Next, we place the already cleaned tripod on the axle and insert it inside the holder, squeezing out the remaining lubricant on top. The optimal amount of lubricant loading for a regular car is 140 g.

All that remains is to reassemble the part, installing a new and intact boot on it, tightly fix all the clamps and install the unit back on the car. Even if the part was not completely new, this will extend its service life for a fairly long period of time, especially if you use your car carefully.

As for the situation when the tripoid bearing is completely out of order, its replacement is carried out according to the principle described above: we remove the old faulty part from the car and install a new one in its place, having previously lubricated it with the required amount of lubricant. The main thing is that the new tripoid is identical to the old one, otherwise you will have to deal with the new breakdown, if not the next day, then next week.

The rapid development of the production of cars with front-wheel drive was hardly possible without a joint that makes angular velocities equal, or a CV joint. The improvement of its use has given rise to discussions about which CV joint is better, tripod or ball.

Why do you need a CV joint?

Today, CV joints are one of the most efficient mechanisms that smoothly transmit torque from the engine through the gearbox to the turning drive wheels without loss of power. Typically, the outer and inner joints are attached to a splined shaft using thrust rings and circlips. The outer one connects to the wheel hub. It transmits torque to the wheel and ensures turning.

The internal one is adapted to axial movements and is installed on the drive from the gearbox side. From it rotation is transmitted to the drive shaft. In this case, the rotation speed of the input and output shafts is the same; it does not change depending on the angle of operation of the hinge.

What are the differences between tripoid and ball

They differ from each other in that the ball type has balls, dividing grooves or levers, while the tripoid type has rollers with a spherical surface and a fork.

The joint where balls are used is usually:

• frame;
• clip with grooves;
• six balls in the grooves of the cage;
• a separator holding these balls;
• protective cover with CV joint lubricant.

This CV joint is connected to the drive shaft through splines.

The tripoid joint has a housing that houses the three-arm fork. It is pressed onto the splines of the output shaft. Three rollers with a hemispherical surface, rotating on needle bearings, are mounted on the fork arms. Under them, grooves are cut out in the tripoid body, thanks to which the desired angle of rotation of the hinge is created and the possibility of longitudinal displacement is created. The functions it performs differ depending on whether the CV joint is internal or external.

Thus, the main difference between CV joints is that the first rotates with the help of balls, and the second - thanks to needle bearings.

Which CV joint is better

On the Internet you can find many opinions of specialists and car owners regarding which CV joint, tripod or ball, performs better. Most of them note the advantages of a tripod CV joint:

• the ability to operate at a 45-degree angle without backlash or shock loads, ensuring sufficient wheel turning;
• more reliable and durable, does not fail instantly;
• greater longitudinal movement than a ball one, which allows you to compensate for loads;
• when the hinge is rotated at a large angle, it better resists loads;
• significantly more resistant to torsion;
• low losses during axial movement and lightly lubricated needle bearings give it high efficiency;
• ease of installation, replacement and maintenance due to sufficient space at the installation site;
• excellent interchangeability with similar devices;
• tripoid has fewer parts and is cheaper to manufacture.

Reliability of CV joints

For durable operation, the tripod and ball CV joints are made of high-strength metals. This ensures the geometric accuracy of these mechanisms and the ability to transmit torque without loss.

Both types of hinges are subject to increased sealing requirements. To do this, they are protected by a rubber or silicone sealed cover, which protects the mechanisms from dirt, water and dust. Such a case ensures many years of operation of the hinge. Its damage and untimely replacement leads to rapid failure of the CV joint.

Tripoids require constant attention because they can break even if a small amount of dust and dirt gets into them.

equal angle hinge

Everyone knows that the engine and gearbox are quite rigidly fixed relative to the body. Through the clutch (or fluid coupling) of the gearbox gear (or clutches), the torque ultimately ends up on the flanges. But the wheels, relative to the same body, can be said to walk on their own. They change both the height and the angle of rotation. And the distance between the flanges and the hubs is constantly changing. To transmit torque, drives with the ability to change length and angle, but without loss of force transmission, must be used. For these tasks, a constant velocity joint is used.

For most car owners, when this term is mentioned, a very specific design probably pops up before their eyes. But in fact, there are several types of them, and even driveshaft crosspieces can easily be classified as CV joints. On modern cars, of course, they are not used in transmissions, but we will focus on the most common two types used in our cars.

the one on the left is called a tripod. Obviously, the name is related to the number of work elements, there are three of them

while the more common design uses six balls

Failure of a classic CV joint is most often caused by destruction of the surface of the inner and outer races

or destruction of the separator

The roller in the tripod is most often destroyed

In non-original tripods, the housing very often wears out. For example, THIS happened 2000 km away

in a “classic” CV joint, due to the larger number of working elements (balls), the load is distributed more evenly, and the appearance of cavities on the holder does not appear immediately. While the destruction of the rollers in the tripod is instantly determined by strong vibration during movement.

——————————————————————————-

p.s. thanks to my muse

In the second half of the last century, cars with front-wheel drive began to be developed, which required reliable drive to the drive wheels. The invention of the constant velocity joint (CV joint), patented in the 20s, came in handy here. Today, almost all passenger cars and SUVs coming off production lines have a tripod joint (internal CV joint).

What is a CV joint and why is it needed?

Conventional cardan joints could not cope with the task of turning the drive guide wheel. Their rotation was transmitted unevenly to the wheels, and the loss of power when turning increased significantly. The tires and the joint itself wore out quickly. Shafts and other transmission elements were overloaded.

The new hinge did not have such shortcomings. The force on the drive shaft was transmitted evenly, regardless of the angle between the shafts connected by it. This fairly simple device can be used for a long time. It has great power when transmitting torque. There is no noise or vibration during operation. The ride and handling in such a car is convenient and comfortable.

Hinge internal and external

To improve operating efficiency, transmissions of front-wheel drive vehicles are equipped with internal and external joints called tripoids or tripods. CV joint tripoids are usually universal; in some car models, needle bearings are used in the internal CV joint tripoids. They are equipped with rollers and a fork that allow displacement of the axes and allow operation at angles not exceeding 20 degrees. In addition to tripoids, there are also ball joints.

Typically, the angular velocity adjustment hinge is:

• a spherical housing connected to the driven shaft;
• cage with drive shaft;
• separator for attaching and holding balls;
• several balls in the separator.

Thanks to such a lightweight design, torque is transmitted smoothly and smoothly, without loss of power. This hinge is quite reliable and is not difficult to replace if it fails.

How to save a tripod CV joint

One of the problems of the CV joint is its imperfect lubrication mechanism. It is actually a boot in which the lubricant is stored. Considering the vulnerability of this rubber or plastic product when in contact with obstacles on the road, there is a danger of dust and dirt getting into it and, accordingly, into the tripoid. This inevitably leads to premature wear of the mechanism.

This issue cannot be left to chance. If fresh damage to the boot is detected, the hinge should be removed and washed. Then install a new one and fill it with special lubricant. After checking the right boot, do the same procedure with the left one. Lubricant for tripod CV joints must have special qualities. It should prevent the destruction of the tripod due to sudden loads on the hinge when the machine starts moving, overcoming climbs, and making sharp turns.

If such a material does not have the necessary characteristics, the mechanism will quickly wear out and fail. For example, the use of lubricants containing graphite is strictly unacceptable. To lubricate tripoidal CV joints, except those with needle bearings, you need black grease that contains 3-5 percent molybdenum disulfide. It should have the right consistency to completely fill the entire unit.

Maintaining constant velocity joints is important to ensure reliable transmission operation. In order not to find yourself in a difficult situation, it is worth making a rule of periodic inspection of the anthers and their timely replacement with joint lubrication. If the fastening clamps break and the boot ruptures, the entire hinge must be replaced.