Special formulations for the “grenade”: 11 CV joint lubricants tested

Elite among lubricants

The resource of modern CV joints (gay joints, they are, as the people say, “grenades”) is quite large. CV joints transmit high torque and undergo significant loads, both mechanical and thermal.

To ensure their reliable operation, the hinges are filled with lubricant and hermetically sealed with a rubber, plastic or silicone cover. If it is tight, the life of the hinge can be comparable to the car’s resource. In practice, anthers self-burst and rupture from outside influences. When replacing, the lubricant must be completely renewed.

It is clear that thoughtlessly applied grease easily pre-finishes the CV joint.

So it’s up to you to choose the right one.

What Are Lubricants?

Different lubricants are used for ball and tripod joints. The fundamental difference is that graphite and molybdenum are necessarily present in the lubricant for a ball joint. Such lubricants must withstand high loads, have excellent extreme pressure properties and stability of properties over time – including in the presence of water and dirt. This is the “elite” among greases, it makes sense not to use them only in ball and socket joints.

A lubricant for tripods is simpler, while the solid components in it are contraindicated.

For testing, we purchased 11 ball joint assemblies with a similar purpose.

Test welds

We decided to compare the tribological characteristics of lubricants according to GOST 9490-75.

We remind you: a four-ball friction machine (Burlage friction machine, ChShM) is a device used to determine the characteristics of friction and wear of samples with the participation of the tested lubricant.

A standard CSM is a test device consisting of three fixed steel balls placed in a cup and one movable above. The top ball rotates relative to the rest at a certain speed and load until the ball is welded to the stationary balls or the specified friction torque is reached.

The field of tribological research is the processes of friction, wear and lubrication.

In this case, we used a four-ball ChMT-1 friction machine as well as an MPB-2 microscope. With their help, three parameters were determined:

• D – the average diameter of the wear spot of the balls at an axial load of 392 N and a test duration of 1 hour;
• hp — critical load;
• PC — burden of ball welding or reaching the frictional moment 1180 ± 25 N·cm.

The welding load is considered to be the smallest load where the machine automatically stops when the specified friction torque is reached, or where the balls are actually welded. The critical load is much more modest: according to the standard, it is determined by the average wear diameter of the lower balls, which must be within the permissible limits.

The test is comparative in nature: the wear spot should be as small as possible, and the load, on the contrary, the higher the better.

Members

Two leaders and two failures

Greases with a contact surface diameter of more than 1 mm are not recommended.

For example, for the Luxe composition, this parameter was 1.35 mm – this means that the CV joint will be cleared three times faster than with Gazpromneft or Elf lubricants, which turned out to be the best in all respects.

SHRUS lubricant test results

The test results refer only to this sample and cannot serve as a basis for judging the quality of products of the same name as a whole.

We thank the staff of the laboratory “LLC NPO Talis” for their assistance in preparing the material.

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