Promotional brochures for the promotion of the fifth modification of the Toyota Rav 4 for our Russian brother contain such definitions as a swift and brutal appearance, a modern interior, an intelligent continuously variable gearbox, active safety and comfort.
As to appearance and interior comfort of the Japanese model-bestseller of the previous Russian sales, it needs separate talk. Our present task is to review the peculiarities of new generation Rav4 transmissions - that's how our garage-boys call it in their slang.
Especially since this is the first time the manufacturer has offered two all-wheel-drive technologies on the Rav 4.
Content
Drive systems of the new Rav 4
Manual transmission in the Rav 4
Stepless or CTV transmission
The drive systems of the new Rav4
One is the classic Dynamic Torque Vectoring already applied to the previous models of the Rav 4 in the form of an AWD System or electronically controlled all-wheel drive automatic with the presence of adaptive and discrete torque distribution on the wheels. Simply put, this is an automatic all-wheel-drive system with rear-wheel engagement when the front wheels start to slip.
And the second is the unique Dynamic Torque Vectoring or the same AWD automatic all-wheel drive technology, but with spacer clutches, on each axle.WhaT gearbox is on the Toyota RAW 4 (5th generation)
The uniqueness of this system is that it enables independent control of the wheel traction vectors by means of an individual distribution of torque between the axles, which significantly improves the degree of controllability of the vehicle at higher speeds in the form of
stability in terms of trajectory control;
confident cornering;
reduction of probability of loss of controllability or on the contrary excessive sensitivity to the driver's manipulations at higher speeds.
It concerns behaviour of the Rav 4 on asphalt road surface.
Concerning character of off-road behaviour of the Ravchik, it is:
Rarely enough cases of slipping of wheels;
confident overcoming of difficult terrains;
Problem-free passage of sections with the possibility of diagonal suspension of the chassis.
Incidentally, about the drives themselves, they are part of transmissions, by the way. If you think of transmissions as mechanisms that transmit rotational forces from the engines to the wheels with different parameters, both in terms of torque values and directions of rotation.
Our next task is to make reviews of both manual transmissions and variator-boxes, what are equipped with new Rav4, because you can read about these cars in the previous publication of merits and demerits of automatic transmission.
That said, keep in mind that some of our garage mates mistakenly refer to the variator as nothing less than a robot.
Manual transmission of Rav 4
It is very easy to determine, what gearbox is on this or that Ravchik. For this purpose it is necessary to look into interior and if on the central tunnel there will be such lever, as on a photo:
Also, if there are three pedals under the steering wheel, it is an indication that the car is equipped with a manual gearbox.
At the same transmission in the Ravchik has an aluminum housing, where spline shafts with sets of gears are installed on the bearing supports, and on the cover of the box - a lever, which is located in the cabin and is designed to use the rocker to implement the inclusion of certain speeds.
At the same time, one has to press the clutch pedal every time to switch over the gearbox to stop the transmission of power from the engine.
Advantages of mechanics are:
Forced shifting in rough road conditions without the risk of overloading the gearbox;
high dynamism in comparison with an automatic transmission, variator or CTV;
low fuel consumption, again in comparison with both automatic and continuously variable transmissions
simplicity and cheapness, both service and repair.
As for the disadvantages of manual gearboxes, we should say that the disadvantages are:
In necessity of constant gear shifting and pressing the clutch pedal while driving in traffic jams with the subsequent failure of clutch as an inevitable consequence of these manipulations;
rapid wear of the synchronizers and locking system;
with the consequence of either difficult engaging or spontaneous deengaging of gears.
Continuously variable transmission or CTV
Concerning the CTV box on the Ravchik, it should be noted at once that the Japanese manufacturer, in order to improve reliability of driving a variator on off-road, where load characteristics are fatal for any continuously variable transmission took the trick, putting the classic mechanics in first gear. Namely, in the form of a block of mechanical gears.
Now the driver of the Ravcik can drive out of snowdrifts or bogs and easily activate the first speed without worrying about the risk of overloading the variator.
The only disadvantage of such a combined CTV box is an increase in weight and number of parts of continuously variable transmission, but almost an order of magnitude increased reliability and durability of expensive unit.
With regard to the principle of the variator box, either the first or the gearbox-like second gear is engaged from the start, when the transmission forces are at their highest.
Then as you accelerate or press the accelerator pedal, the electronic variator pulley translation control kicks in. This ensures a smooth shift of speeds up to and including sporty sequential modes (which increase the wheel speed in sequence) in the new RAV 4.
