At the moment, there are cars with different types of drives. It is front, full and rear. When choosing a car, the future owner should know the features of each. Most professional drivers prefer to buy a rear-wheel drive car. What are its features? We will talk about this in our article.
Characteristic
Rear-wheel drive car implies the presence of a classic layout and placement of units.
The engine and gearbox are located longitudinally. This is the simplest scheme. Therefore, the
first cars were with rear-wheel drive. But recently, there has been a tendency to switch to front-wheel drive. It is considered more technological. But manufacturers such as BMW, Mercedes and others still do not give up on the "outdated" layout.
Device
The rear wheel drive car does not have a transverse engine. A simplified scheme is used here.
First comes the engine, then the gearbox, driveshaft and axle with differential. Unlike the front rear-wheel drive car has a more uniform weight distribution. Unlike “technological” analogues, the mass here is not concentrated at one point. Hence the more correct distribution of mass and load.
The main nodes are:
- Cardan shaft.
- Rear axle with differential.
Let's look at the features of each element.
Driveshaft
It is a cylindrical steel rod. Through the crosses, this shaft is attached to the gearbox. On the other hand, the mechanism is connected to the rear axle. The driveshaft is located under the body. If it is a passenger car, a special tunnel is put out to accommodate it.
This is necessary so that the metal rod does not deform against stones and asphalt.
Cardan transmission is very reliable. However, the main problems relate to crosses. They constantly fail. And no matter what brand the rear-wheel drive car was produced. The exception is SHRUS connections. They were first used on the Niva. However, Ulyanovsk Kozlik (UAZ 469) still uses crosses as the main compound.
Rear axle
In its case there is a differential. It is located in the middle of the bridge. It is this mechanism that receives torque from the cardan transmission. Axles are integrated in the differential of the rear axle. They reliably connect with wheels. When the driveshaft rotates, it drives the differential.
That, in turn, rotates the wheels through the axle shaft. Also note that inside the rear axle, transmission fluid is used to lubricate the differential gears and half shafts. In order for it to not leak out, seals are provided in the design. On some cars, the
rear axle is also recessed into the body so that the mechanism is less damaged. However, this significantly reduces the space in the cabin and trunk. But why, then, are rear-wheel-drive cars of the brand BMW, Infinity and so on? There are reasons for this. Let's look at the advantages of this type of drive.
pros
The first plus is the free space under the hood. Rear-wheel drive cars have it much more due to the uniform arrangement of elements. On the front-wheel drive, all nodes are assembled precisely in the engine compartment. This makes car maintenance difficult. The next plus is the correct weight distribution. Thanks to this, we get a uniform load on the front and rear axles. Also, this type of drive transfers less vibration to the steering wheel and the body itself. The car perfectly obeys the steering wheel.
If desired, you can enter a controlled skid. The rear axle of the rear wheel drive car will not be anything. If you release the gas, the machine will level out again and continue driving. That
rear-wheel drive is suitable for drifting. The driving load is carried out on the rear axle, and the front only performs a control function. From the transmission and other components you will not hear vibrations, as is the case on some cars with front-wheel drive. The next plus is maneuverability. In the design there are no CV joints on the front wheels, and therefore the turning angle is much larger. This is very useful when driving in traffic or during parking. The eversion angle on such cars is 15 percent more than on the front-wheel drive. Also note the high maintainability. The service here is much cheaper. Not surprisingly, commercial vehicles are still equipped with this type of drive.
Acceleration dynamics
We will pay special attention to this aspect. On such machines more dynamic acceleration.
If you overdo it with gas, then at the start you can get a rear-wheel drive car skid. At this time, the car body goes back. Based on the laws of physics, the load on the rear axle increases. As a result, the wheels get a larger hook. The machine does not grind, as it is on the front-wheel drive. And no matter what engine power - the result will be about the same. Therefore, in drag racing, only cars with rear-wheel drive are used.
disadvantages
The design involves the presence of many additional nodes. This cardan, bridge, differential, axle shafts. While to transmit torque to the front-wheel drive, it is sufficient to use a constant velocity joint. Therefore, the price of such cars is slightly higher. The next is the presence of liquids. The differential uses about two liters of gear oil. It should be changed every 30 thousand kilometers. In SHRUS, lubricant is clogged for the entire service life. It is required to carefully monitor the condition of the seals. If the bridge flows, it is very bad.
With a low level of lubrication, the differential teeth wear out more. And the cost of a new bridge, even for a domestic UAZ, is at least 40 thousand rubles. Another drawback is the presence of protrusions in the passenger compartment for the driveshaft and rear axle.
About patency
In terms of snowy roads or dirt, rear-wheel drive loses significantly. Wheels push the car from behind. As a result, he "digs" a snow trap for himself. The car begins to bury. Therefore, on off-road vehicles, it is used (no, not front-wheel), but all-wheel drive. However, due to the presence of two bridges and a transfer case, the design is significantly complicated. This entails costly repairs to components and assemblies. But in terms of cross-country, he is a leader.
What are rear-wheel drive cars?
As we said earlier, now this arrangement is done only on expensive cars. These are German BMW and Mercedes, Jaguar, Infinity, Maybach, as well as some Japanese Toyota and Nissan cars. Among domestic, this is the Volga and the classic VAZ models. And of course, all commercial equipment. Budget cars with this type of drive are not currently being produced.
Conclusion
So, we found out the features of rear-wheel drive. Despite the popularity of the rival front, it still remains relevant. This is especially true for commercial vehicles. After all, there is a frame design. And there is simply no point in making ledges under the bridge and cardan - the truck’s ground clearance allows them to be used without additional tunnels.