Cardan shaft, "Gazelle": repair and replacement

A propshaft is an element of the transmission system for vehicles with full or rear-wheel drive. This element is used to transfer torque from the transmission box or the transfer case to the rear or front axle. The propeller shaft on the "Gazelle" also performs this function. Let's look at his device, and also learn how to maintain and repair it.

From the history of cardan shafts

The shaft was called cardan by the name of the inventor, who worked on his creation. This was an Italian specialist in medicine and mathematics - Girolamo Cardano. It was he who first invented the mechanism on hinges, with which today it is possible to connect rotating parts and assemblies.

Specialists-historians believe that for the first time the cardan was invented by Leonardo da Vinci. It is very interesting here that the author of this development wanted to be another person. This is Robert Hook, but he could not get his patent right away. He was given it a little later.

To use this design in cars became in 1898. The first was Louis Reno. This is a simple, but at the same time very efficient drive, which today is the practical only possible option for torque transmission. Today, on virtually all types of vehicles, a cardan shaft is used.

"Gazelle": shaft assembly

This element works as part of the cardan gear. And it, in turn, consists of an intermediate shaft, intermediate supports, a rear shaft and three hinges. We will examine each of them.

Intermediate shaft

This unit is made in the form of a hollow steel alloy tube. A feature of the shaft is a pipe with thin walls. From the rear end part on the shaft is fixed the shank, which has external splines. The front end of the shaft has a special fork. To this fork, another sliding fork is attached through a special hinge. On this part there is an internal splined hole, and also a mud reflector is applied.

Front fork

This part is installed in the extension of the rear crankcase on the gearbox. It is in mesh with the splines, which are cut on the secondary shaft. When the rear suspension is triggered, the driveshaft ("Gazelle" or "Valdai" does not matter) can move longitudinally. In order to maximally compensate for these movements, the shank can move along the splined portion of the output shaft of the gearbox. This connection is constantly lubricated with oil, which is located in the crankcase.

Intermediate support

This element is made of rubber. It is corrugated. From the inside, a ball bearing of closed type is attached to this support by vulcanization. On the outside, the support is equipped with a special bracket.

Thick rubber does not allow transferring vibrations from the movements of the transmission to the body parts, and also allows for the movement of the cardan gear along the longitudinal axes.

The bracket is bolted securely to the cross member of the vehicle frame.

The bearing, which is installed in the support, has a very long service life. He does not need any care during his lifetime.

The rear shaft is also made of a steel pipe with thin walls, but fork ends are attached to the end parts. Through the special hinges in the front part of the workpiece, the spline fork from the middle element is fixed. It, in turn, is fixed to the splined part of the intermediate shaft. So, first comes the propeller shaft support. The gazelle is then completed with a fork. To ensure that this part does not move along the splines, a bolt is provided that fixes the plug. On the other side of the rear shaft, a flange is mounted by means of a cross, which has a special centering belt. The flange is fixed by means of bolted connections to the drive gear of the main gear in the gearbox.

Pivot of propshaft

The shaft is equipped with a hinge that consists of forks, as well as a cross. It has four needle bearings in its design. Each bearing has 20 rollers in the cage. Their diameter is 2 mm. These needles are manufactured using high-precision equipment. They are specially selected for these bearings in assembly with the crosspiece. Do not attempt to replace needles that are removed from different bearings. It is also unacceptable to only replace the propshaft spider. "Gazelle" also can not be repaired, only replacing some bearings. What is allowed is the replacement of the entire kit as a whole. Change it is necessary, even if only one bearing is damaged.

For lubrication, the crosspiece is equipped with a grease fitting. From this oiler, the lubricant, which is injected by a syringe, falls through the inner lubrication channels to the bearing rollers. To keep the oil inside, the crosspiece is equipped with a special rubber cuff. When the lubricant is injected, the spring in the cuff stretches, and the excess oil flows out of the cage.

The needle bearing is pressed into the holes of the forks and securely secured with locking rings.

These lubricants are greased by transmission oil, which is not always convenient and effective. So, the crosspiece and forks have to be filled with oil very often. It is recommended to use composition No. 158 for lubrication. This lubricant is so thick that it will allow you to forget about the bearings in the cross for a long time.

Typical malfunctions

Like any other detail, the driveshaft ("Gazelle" in this regard is no exception) may be out of order. But many problems can be solved. Let's look at the most basic malfunctions of this node.

Problems associated with vibration

So, if you feel stable vibrations when driving a car, it is possible that the shaft tube has deformed. To eliminate this, you do not need to apply any special or harsh measures. Often it is enough just to replace the pipe completely or to order the repair of cardan shafts. "Gazelle" can be repaired in any car repair shop, in which locksmiths carry out similar work. When carrying out replacement or repair, it is necessary to perform balancing of the shaft.

In addition to deformation of the tube, vibrations can occur if the fastening of the rear shaft fixings to the bridge is loosened.

To do this, you can completely pull up loose connections.

Often, vibrations occur due to tearing off the balancing plate from the propshaft tube. In this case, it is necessary to replace this pipe or repair it in a car workshop. But here you also have to do the balancing.

If the vibration is felt steadily, then it is worth checking the part for possible play in the bearings. It is useless to repair here, and the replacement of the propshaft spider will help to get rid of the vibrations. The "Gazelle" after such an operation will be as new.

If there are beats in the landing zone on the gear flange on the rear axle gearbox , then there will be enough replacement of the flange. If the runout of the sliding fork in the gearbox becomes noticeably larger, the transmission extension cable should be replaced. This wear is due to the wear of the bushings from the steelbabbit.

In the event that the backlashes in the joints with the splines are increased, if the bearings or the cross of the propshaft are worn out, the "Gazelle" is repaired by replacing old parts with new ones.

Breakages detected when removing the cardan

Unfortunately, not all the problems of the elements can be detected during the movement of the car. Many faults can be detected only after removal or a thorough inspection.

So, if oil leaks from the hinged joints, then this indicates that the cuff that should hold the oil is damaged. It simply needs to be replaced. If the cap is rotated along with the collar, then the cardan cross is replaced, and then the shaft is balanced.

If, after a run of 40,000 km, the oil does not leak out of all oil sump cuffs, then a small repair must be carried out. If it is difficult to understand how to disassemble the driveshaft ("Gazelle"), the photo accessories from our article will help significantly speed up the process of removal and disassembly. So, to perform this repair, it is necessary to remove the gear, dismantle the hinges, clean the lubrication channels of the crosspiece, replace the bracelet springs and put them on the stuffing boxes. Then you should collect everything back, and give the shaft for balancing.

How to remove the cardan from the car?

What do you need in order to repair the cardan shafts? "Gazelle" must be prepared for this operation. This is a simple procedure, but you should know the correct procedure.

Before removing the gear, you need to mark in advance with the paint the places of the mutual angular position of the fork, and also the shaft of the gearbox. These marks are very convenient on the reflectors of the sliding fork, as well as on the extension cable.

The threaded part of the bolts should be cleaned as much as possible from the adhered dirt. Then these bolts are unscrewed. Then, the nuts that secure the intermediate support are turned away. As a result, the support will be freed from the cross member of the frame. Then the entire cardan gear is shifted forward and disconnected from the flange on the bridge. To make this operation as easy as possible, you can use a hammer, but only through a copper or brass gasket. You need to strike on the flange on the rear hinge.

After that, you can remove the front sliding end of the cardan gear.

At the end of the driven shaft of the gearbox, a position mark must also be placed.

When the transmission is completely removed, it is necessary to protect the shank of the plug as much as possible from possible contamination. The hole in the checkpoint also requires the same.

Now you can start troubleshooting various problems.

Purchase of new

Buying a new node to replace the damaged one, it is necessary to take into account the dimensions of the cardan shafts. "Gazelle" is no exception. The fact is that for different models there are different modifications. So, on models with a standard wheelbase, standard length units are installed. These parts can be bought in many car shops.

The situation is worse with the extended models of cars. These shafts are available on request, and not everywhere they can be purchased.

Today, there is a lot of information about the extension of this element on its own. So, the propeller shaft ("Gazelle") can be extended if the owner wants to increase the wheelbase of his car. This gives certain advantages - a large length of the cargo hold.

Cardan shaft - the same detail as all the others. This node can be completely repaired. With proper care and regular maintenance, it will last a very long time. And if you need a replacement, then remember that for the car the length of the propeller shaft ("Gazelle" and "Valdai" in this row is no exception) is the most important parameter.