Tip 1: How to make a four-wheel drive
Tip 1: How to make a four-wheel drive
The driving wheels are located on the axis to which the torque is transmitted: these wheels are connected to the engine. The driven wheels just roll. There are several types actuators: front, rear and full. Each of these drives has its own characteristics.
You will need
- - instruments;
- - Differential;
- - Viscous coupling.
Instructions
1
Find out the basic principles of the all-wheel drivecar. The main node in this system is the differential. To ensure a different speed of the driving pair of wheels using an inter-wheel differential, and the drive shafts - the interaxle differential.
2
The differentials used can beblocked and free, as well as symmetrical and asymmetric. The twisting moment in symmetric differentials is distributed equally among differentials, and in asymmetric differentials it is distributed unequally. In order for the all-wheel drive to work normally, the transmission should have an interaxial and two inter-wheel differentials.
3
In modern all-wheel drive vehicles, a viscous coupling is used. The device uses a silicone fluid, which helps to reduce the difference in the speeds of rotation of the drive shafts.
4
When one of the wheels slips as a resultheating significantly increases the viscosity of the silicone fluid, because of which the viscous coupling discs are connected, and the rotation of the drive shafts is carried out at the same speed. To create an all-wheel drive, use a combination of the interaxle free differential and viscous coupling, which act as a locking device that operates in an automatic mode.
5
The second device intended for blocking- differential of increased friction. During the motion, such a differential distributes the torque between the axles equally. The principle of operation of this device: as soon as the slippage of the wheels of one axis begins, the torque immediately moves to the second axis, the wheels of which have better grip.
Tip 2: How to turn on the drive
Very often situations arise where the use of full drive just necessary. And it's not necessarily any rally or competition of SUVs, on the most glass burrowing into the mud. Ice and loose snow, dirt and deep gauge - all these are the reasons for the slippage of the car. To solve the problem, you must connect the second driving axle.
Instructions
1
Connection diagrams of the complete drive can be different. It all depends on your car. There are cars with a permanent front-wheel drive and a connectable rear axle. Other cars push their rear wheels all their life, but can turn on the front ones if necessary. But whichever axis is connected, in all modifications of cars it is possible to distinguish several basic algorithms for including a full drive.
2
3
Classic part-time with manual connection of full drive designed for use inoff-road and at low speeds. But as soon as the speed of the car increases and reaches (in different cars in different ways) 40 or 60 km / h, the second driving axle will automatically turn off.
4
In domestic cars and foreign cars of older age to connect the full drive it is necessary to transfer the transfer case lever toposition 4WD. In addition, you need to check whether there are special couplings on the connected wheels. If there are clutches, then you must also set the switch to the 4WD position.
5
You can disconnect in any order - first the clutch, then the transfer case lever to the 2WD position. If you know that after a short interval, you will again need to connect a full drive, then the clutch can not be disconnected, and do this only after the final exit from the difficult part of the road.
Tip 3: How to choose a car park
Crossover or "steamer"Is called a city car with increasedcross-country ability. A distinctive feature of the machines of this segment is the increased ground clearance, differential lock, reduced gear, etc. But the full drive may be absent. When choosing a vehicle, you should pay attention to some key points.
You will need
- - computer with Internet access;
- - magazines on automotive subjects;
- - A newspaper with ads.
Instructions
1
First decide which brands of cars you needlikes more than anything. Then make a list of requirements for the desired machine: what kind of gearbox, engine size, type of fuel (diesel or gasoline), drive, availability of additional options and more. All this will help to make a choice of a specific model among the manufacturers you previously selected.
2
Then set the price frames for the crossover,so that in the future not be distracted by viewing the "dead-end" options. Select several models of different brands and compare them among themselves. If possible, read reviews about them on the Internet or in specialized magazines. Mark all the pros and cons based on your wishes. In addition, consider the cost and availability of spare parts, the possibility of maintenance, self-repair, etc.
3
When choosing a crossover, you should know thatmodels of different automobile concerns have their weak points. Therefore, before appointing a meeting with the seller of used cars, get acquainted with these nuances, so that when looking to pay special attention to problem areas. So, for example, in the popular Toyota RAV4 model, this paint and varnish coating, the engine (if the timing of the valves of the gas distribution mechanism has not been periodically adjusted), shock absorbers (if used improperly, start to leak and knock), etc. At Audi Q5, pay attention to the panoramic roof (if it is - can squeak when driving), check the performance of the air suspension compressor, pressure sensor, gearbox (DSG or conventional automatic transmission), etc. At Hyundai Tucson, check the stability stabilizer (ESP can be switched off when the steering is not fully rotated), no clatter of the rear suspension, clutch operation, and more.
4
Do not forget to inspect the body for rust,defects in paintwork (bloating, mismatched body parts according to the tone of paint or a completely repainted body, etc.). Look under the car: there should not be any leaks of oil, antifreeze, gasoline. Open the hood and inspect all transmission belts for wear. Listen to how the engine works. About its malfunctions when you press the accelerator pedal, there will be different knocking and speed changes. In addition, check the dampers, all lights, clutch pedals and brakes.
