Questions and disputes concerning the subject arise with the enviable regularity.
Let's try briefly to explain, what is 4WD on the second generation of Caldina...
Thus, Caldina in 210th bodies from August 1997 were produced in the next variants:
The principles of 4WD on 215G and 215W differs from each other radically. In the old good Toyota's traditions FullTime 4WD, installed to the initially front-wheel-drive models, it was actually constant and full, with three differentials, including center, located in the common case with the gearbox. Central differential could be lockable - by servo (C.Diff Lock), either by viscous coupling, or automatically, by hydromechanical multiclutch coupling with electronic control (C. Diff Auto). But now everything became differently...
Caldina 215 4WD variants
On Caldina 215G 4WD was realized on the new fashion, known under the general name "V-Flex Fulltime 4WD". It's not "honest" Fulltime 4WD - actuallly, it is the scheme with the auto-connected rear axle (more precise, rear wheels). Center differential was eliminated, and the torque, is take out in the automatic gearbox, through transfer (or, simply, bevel gearbox) is drive by propeller shaft to back...
But now, before the rear differential was mounted the viscous coupling, which operates and connects the propeller shaft and the input shaft of rear differential only if front wheels slipping. In the other time the car remains front-wheel-drive. However, version GT obtain the rear limited slip differential Torsen type.
It is necessary to explain - in technical English all limited slip (self lockable) differentials calls the united concept "LSD". However, in reality they are divided, at least, to locking with "closed type" viscous coupling, with "open type" viscous coupling, friction type and mechanical type. "Closed type" coupling is filled with silicone liquid or LSD-oil, but its internal cavity does not communicate with the case of differential. In "open type" - the disks and the plates of clutch work directly in working fluid of the differential. Torsen differentials work on the other technical principle and use ordinary transmission oil.
On Caldina 215W the construction scheme of 4WD is traditional and valuable, with the lockable center differential, placed in the gearbox case. Alas, there is a viscous coupling in this differential now, not a multiclutch "intelligent" coupling. Torque is transferred by propellershaft to the input of rear differental, where is mounted usual free differential (on the version with the automatic gearbox) or the LSD Torsen type (with the mechanical gearbox).
"Where can we find fluid capacities?"
Here are Toyota's advices:
* - TM - Transmission (gear) oil.
|A245E||7,6||ATF Type T-IV||-||-||-|
|A241F||8,1||ATF D-II||MF1A||0,9||TM GL-5 75W-90|
|A243F||8,1||ATF D-II||MF1A||0,9||TM GL-5 75W-90|
|U140F||8,1||ATF Type T-IV||MF2AV||1,0||TM GL-5 75W-90|
|C58||1,9||TM GL-3 SAE75W-90||-||-||-|
|S55F||2,1||TM GL-3 SAE75W-90||MF1A||0,9||TM GL-5 75W-90|
|E150F||5,2||TM GL-5 SAE75W-90||EF1AV||gearbox case integrated with transfer case|
** - all gearboxes have front differential case, integrated with gearbox case (not to be charge separately).
*** - "GL-3" here understand as "GL-4".
Rear differential - transmission oil for hypoid gears GL-5 SAE85W-90 (0,5 l. - V-Flex, 0,9 l. - GT-T)
There is the "LSD-oil" in viscous coupling of rear axle connection mechanism, but not attempt to disassemble it.
As it proved to be, for the part of owners ST215G this principle of 4WD became discovery and, it is similar, unpleasant dicovery. So let's pass through basic questions...
"Why V-Flex is bad?"
1) So that the viscous coupling begin to work, necessary the slippage of front wheels. Only in this case the perceptible difference in the frequency of rotation between its disks will appear, will begin warming-up and "hardening" of working fluid. But car can "bury" in soil more rapid, than rear wheels will move.
2) Locking by viscous coupling never was "hundred per-cent" and its disks nevertheless will slip.
3) Massive elements of the real Fulltime 4WD can bear overload easily, than the elements of sufficiently tender coupling.
4) "Connected rear drive" is potentially dangerous with the rapid ride, especially during the cornering. Therefore to avoid the random connection of rear drive (with the critical drift of the car and all ensuing consequences) coupling was made with the "soft characteristic", so that it would react only to the sufficiently large and prolonged difference in the frequency of rotation - but it made worse cross-country ability.
So, functionally V-Flex worse than the real Fulltime 4WD, which was stood on Caldina ST195, but nevertheless it is better than nothing - simply "all-wheel-drive to make sure".
"We start fully jacked-up car. So rear wheels also rotating? Why?"
If we start engine of frozen VAZ and drop the clutch, the car will be rolled forward even with neutral position of gearbox - because oil in the box is thick. Here also through the clutch, due to internal liquid friction, minimum effort is transferred constantly. For its real application it will not be sufficient, but it will be possible to rotate the freely hanging wheel easily.
"What diseases in V-Flex?"
1) The most unpleasant - when car arbitrarily long time skids one of the front wheels, but rear do not think to be connected. If it was not happen during extreme off-road, than probably viscous coupling (41330D) broke. But new (p/n 41330-12020) cost near 1100 US$, so that remains either to go to scrab collector (here all rear differential from worn out car costs ~400 US$), or resign of 4WD and use "mono-driving" car. On the happiness, this problem is sufficiently rare.
2) Is considerably more extended another - the whistle (or gnashing) of the radial bearings of viscous coupling (in the figure - 41330G and 41330F). But nothing terrible, these bearings (p/n 90363-95003 and 90363-65002) detachable and costs about 30 US$ both (to change better both at the same time - "in order two times not to walk"). In case of unsuccessful disassembling could be required other dust washer of bearings (in figure p/n 41252).
Moscow, jan 2004