In detail: do-it-yourself cardan joint repair from a real master for the site my.housecope.com.
The constant velocity joint (CV joint), which is usually referred to simply as a "grenade", performs an important function and is the most important component of the car. The CV joint transmits torque from the gearbox to the drive wheels, while setting the direction of movement. That is, in addition to rotation around the axis, the CV joint must be able to turn, usually the angle of rotation is limited to 70 degrees.
Based on the purpose of the CV joint, we can conclude that it is used in vehicles with all-wheel drive and front-wheel drive (that is, in those in which the drive wheels set the direction of movement).
The vast majority of modern cars have front or all-wheel drive, so understanding the design of CV joints and their possible malfunctions will be useful for every car owner. Further, in the article we will briefly describe the CV joint drive device, as well as its most frequent malfunctions and their causes.
Before you start any repair work or try to diagnose a problem, you need to be clear about what you are dealing with. Therefore, below you will see a photo of the CV joint drive, on which its elements and their names are signed:
For a complete picture of the structure of the drive elements, below you will see its sectional image:
This unit is very reliable: under normal operating conditions, its service life can exceed the service life of other elements of the car. However, the ingress of a small amount of dust, dirt or water into the hinge increases the friction in the hinge many times over, thereby increasing its wear and tearing it down. Due to their importance for the normal operation of the car, CV joints are well protected by special "protective covers" - anthers. They provide the hinge with reliable protection against dust and dirt, as well as complete tightness. Usually, anthers are made of dense rubber or plastic and are fixed to the drive shaft with clamps. By the way, usually anther clamps have a slightly unusual appearance. In the photo below you can see the clamps on the anthers, a special tool for tightening them and the tightening process itself:
Video (click to play).
One of the main causes of CV joint failures is related to the ingress of dirt or water through damage to the anther. If it so happened that your anther was damaged and dirt got into the hinge, you must immediately inspect it and then clean it (repair if necessary). To do this, remove the drive, rinse all its elements. Next, make sure that there is no excessive wear in the elements and install them back after filling the CV joint with fresh grease.
A damaged boot can be repaired with a regular tire patch and sealant. Also you can use the repair method as in the video below:
There are two ways to detect possible malfunctions in the external (external) CV joint:
visually detect a violation of the integrity and tightness of the anther: cracks, kinks, traces of grease on the outside;
by characteristic sounds (characteristic crackling, crunching) when turning the steering wheel, entering a turn, etc.
If you have disassembled the outer CV joint and found wear on one of its components, then it is possible to significantly extend the life of the hinge without replacing it. First of all, if you find the wear of the separator at the points of contact with the balls, then there is no point in panicking. The rolling elements are installed in it with a gap, and a significant one, so that the development at the points of contact is completely harmless. Another thing is if wear appeared on the rolling elements themselves or elsewhere in the separator.
If only the rolling elements are worn out, then their repair is not possible.But finding the same ones at the nearest car parsing, car market or car shop is not difficult. The main thing is to choose the balls of the desired diameter.
If the separator is worn out, then there are two main repair methods:
replace the entire outer CV joint;
replace separator;
swap CV joints.
The first method is simpler and most preferred, although it will be more expensive than the second. A lot of articles have been written about how to properly replace the outer CV joint and many video tutorials have been shot. There can be many features and subtleties associated with each specific car model.
The second way is to purchase a repair kit (which are produced mainly for domestic cars) or find an external CV joint for your car during disassembly, remove the separator from there and install it in the old CV joint. Naturally, before installing a used separator, you need to make sure that there are no visible signs of wear. Next, immerse it in a rust converter if it shows any signs of corrosion. After that, it will be useful to clean it with sandpaper.
The essence of the third repair method is to rearrange the grenades of the left and right axle shafts in places. This will help, because the direction of rotation of the rolling elements will change (there will be unworn areas involved). However, this will cause a crackling sound when reversing.
Another "cunning" way that allows you not to spend money on the purchase of the entire CV joint or its components. However, not every car will be able to “repair” in this way. Its essence is to replace the outer cage separator with the inner cage separator. There are, of course, two conditions:
First, the separators must be identical to each other.
Secondly, the wear of the outer ones should not be too strong, and the inner ones (ideally) should have almost no wear.
Since these two conditions are not met on all car models, therefore, such repairs can not be made on any car.
The inner CV joint, as well as the outer one, is protected by an anther from the outside. Accordingly, if its integrity is violated, dirt and water enter the hinge, which leads to its failure. The methods for repairing internal CV joints in this situation do not differ from repairing external ones: they must be washed, lubricated and the damaged boot replaced.
Another main problem with internal CV joints is the backlash of the drive shaft from the gearbox side. Visually, the difference between the "normal" state and the backlash can be seen in the video below:
