The car has a huge amount of moving parts. Some of them interact with each other. The inevitably frictional force arising from this must somehow be compensated. This is especially true for rotating parts. Excessive frictional force leads to heating of the part, its thermal expansion and jamming. Bearings are intended for elimination of this phenomenon.
Hub bearings and greases
The element is designed to reduce friction, converting it to easier rolling. The bearing is one of the critical components of the chassis. Wheel hubs also can not do without these devices. Many factors depend on the ease of rotation of the element.
These are car stability, fuel consumption, acceleration and braking times. However, the wheel hub is a very loaded mechanism. To ensure ease of rotation of the bearing, it needs lubrication. It further reduces the frictional force in this assembly.
Grease application
This component reduces friction or, in the absence of moving parts, ensures the fit of the parts without their rigid connection to each other. Greasing provides easy sliding of surfaces relative to each other. This significantly extends the life of the part.
What formulations are not recommended for use in hubs
So, we need grease for the bearings of the hub - which is better? Her work is quite specific and is influenced by many factors, internal and external - the high speed and temperature changes leave their mark on the work of this unit. Such features make it impossible to use lubricants that include synthetics. These are petroleum jelly and silicone materials, which are on sale in a wide range. Unfortunately, they stop working already at 50 degrees.
The next type of grease, which is not recommended for use in wheel bearings, is based on sodium and calcium. Such compositions significantly reduce friction, but are completely resistant to corrosion. Rust in the bearing is always bad. Another type of widespread composition is graphite-based. If we need hub bearing grease, which one is better? The graphite composition is classified as high temperature. The lubricant contains a large number of abrasive elements, which catastrophically reduce the life of the rubbing parts. Such products are used for sedentary joints (for example, between separate pipes of the exhaust system) or on separate metal parts for protection against rust. On average, when using graphite lubricants, the resource is reduced by three to four times in comparison with the recommended types of compositions.
It is also not recommended to use products containing zinc and iron. To be more precise, it can be used, but not necessary - it is well suited for industrial use (on machines and other equipment).
Recommended Lubricants
Modern developments provide the widest selection of lubricants. The use of various additives and additives significantly improves the initial qualities and physical properties of the compositions. So, if the question is about choosing a composition such as grease for wheel bearings, which is better?
With molybdenum content
Such a connection is very effective for working under given conditions. This ensures an optimal balance between the quality of lubricating properties and the fight against corrosion. The resource of this lubricant is equivalent to 100 thousand kilometers. This is comparable to the life of the wheel bearing itself.
However, this lubricant has its drawbacks. Firstly, it interacts poorly with moisture, so bearings with this filling must be closed. The grease must not come in contact with air, and in case of depressurization, it must be completely replaced and inspected for all rubbing parts. Also, the composition is subject to contamination. Abrasive particles accelerate the wear of the grease and bearing itself. The most common brand of domestic products is FIOL and SHRUS-4.
High temperature grease
It incorporates nickel and copper additives in the form of a powder. Such lubricants (for example, MC1510) do not lose their stable characteristics at high temperatures, up to 350 degrees. They also have high oxidative stability.
High temperature grease for wheel bearings is one of the best. Its working range is from -40 to +180 degrees. The composition shows itself well under sharp braking, acceleration and temperature changes. The addition of special additives provides high resistance to oxidation and corrosion.
Lithium greases
These are materials containing lithium in organic acids. Such lubricants are universal and their scope is very wide. Externally, they can be distinguished by a light yellow tint. The service life of bearings with this grease is also very high. The resource, subject to operating conditions, approaches the service life of the bearing itself. Therefore, lithium grease for wheel bearings is a good option. It is also worth noting the return of the composition to its characteristics after overheating. Foreign companies producing lithium grease are BP, Very Lube and Renolit. The domestic manufacturer has established itself as the only single product - Litol-24. This product is already known to more than one generation of motorists.
Substitution
Changing the grease in the hub bearings is not such a difficult task. The car is braked reliably and after that the hub nut is loosened with the help of an end head and a long wrench. Next, the wheel is hung out and removed. The brake disc is also dismantled, and the hub is disconnected from the steering knuckle. After that, the hub fastening nut is finally turned away. With the help of a hammer, the element is knocked off the axle shaft.
The bearing is pressed into a cage, which must be removed with a special puller or a strong flat screwdriver around the circumference of the ring. The latter can stick. In this case, WD-40 or kerosene will help. Old grease is removed with kerosene or gasoline. They wash the entire bearing, cage and seat in the hub, and then wipe it dry. Use clean rags.
New grease is applied to the cage in an amount of about 30-40 g per bearing. Using a screwdriver or a wooden stick, it is evenly applied to the bearing surface. Next, the element is installed in the hub and centered by a clip. Installation is carried out using a suitable mandrel or cage from an old bearing. Further assembly is carried out in reverse order. Lubrication of the
rear hub on cars with drum brakes is carried out similarly. Only here is the bearing removed without removing the hub from the vehicle. It goes a little faster in time.
Features of lubrication of hubs in domestic cars
Lubrication of the bearings of the hub ("Niva" including) is carried out similarly to the procedure carried out on foreign cars. However, it is not necessary to remove the hub from the car here. It is enough to leave her hanging on a rack. A lithium-containing and high-temperature grease is embedded in the bearing. As for the UAZ hub, grease is also laid in them. But there is a difference between the front and rear axles. In front, the hubs are pulled together from the axle shaft using a puller, and the bearing together with the gland can remain on it, which is even easier. In the rear axle, grease for the bearings comes from the rear axle housing. Nevertheless, there bearings can be changed and lubricated. Work does not take much time.
Operational Reliability
So, if you need grease for wheel bearings, which is better? Each vehicle is shown its own type of lubricant. It is indicated in the instruction manual. Specific brands and brands of lubricants are often indicated. As experience shows, the most versatile is lithium-containing. Nevertheless, at certain intervals, a visual inspection is required, and at the interservice intervals, a replacement of the composition is required.