How does the full time 4WD work in Prado ???

[97RV6 Lurker Find all posts View Profile Close 97RV6]

Hi,

I have come from a traditional transfer case background and am trying to understand how the Prado full time 4WD system works.

Can't seems to find any detail anywhere.

I like to know how these things work so I can understand the limitations / benfits.

Cheers
John
:?:

[Guest Close Guest]

Full Time 4WD also called permanent 4WD and constant 4WD

Main mode is 4WD. 4WD is used full time.

No 2WD mode available.

All four wheels are powered at all times. Operates well on dry pavement due to a center differential or equivalent device (planetary gears, etc).
Part Time 4WD does not have a center differential.

A center differential is essential for on-road use but can be detrimental for off-pavement use. When leaving pavement the center differential needs to be disabled (locked). It either locks automatically* or it has to be locked (disabled) manually.

Normal setting for on-road use and light duty off-road use is 4WD "high", also called high range.

For more torque 4WD "low", also called low range, is available. Low range provides substantially more torque to the wheels and allows slower speeds than in high range. 4 low does not provide more traction - it only provides more torque.


Full Time 4WD requires:

a transfer case

a center differential

two drive shafts

two axle differentials

two powered axles

Hope that clears it up.

Try Google like I did.

[97RV6 Lurker Find all posts View Profile Close 97RV6]

Thanks Wizard

The learning continues

Thanks for the information wizard.

So when I have it in high but not locked, and one wheel comes off the ground
assume all drive is lost. But if locked she still has drive?

I will google and see if I can get info on this.

again thanks
cheers John

[Brent Lurker Find all posts View Profile Close Brent]

hey 97rv6,

If yours is the same as mine (2000 gxl) then it has the 4wd lever with H, HL, N and LL.

So the L denotes Locked for the centre diff. In normal drive the centre diff puts power to both front and rear axels, however if for example one of your front wheels loses traction, the centre diff then transfers all power to the front. Which means you spin the one wheel and go nowhere.

When you have it in HL, the centre diff is locked meaning that drive is 50/50 front and rear regardless of traction. The gearing however is the same as driving on road. LL is locked 50/50 but reduces your gearing greatly for different 4wd situations.

You can see this on the sand quite prominantly, if you leave it in normal drive you can still get in most soft sand entrances with heaps of momentum, slow it down however and you will be going along nicely until all of a sudden one wheel will just open up and you will stop. If you do the same thing in HL you will just drive through with little effort 90% of the time.

Hope this helps mate,

Brent

[97RV6 Lurker Find all posts View Profile Close 97RV6]

Thanks Brent

hey 97rv6,

If yours is the same as mine (2000 gxl) then it has the 4wd lever with H, HL, N and LL.

So the L denotes Locked for the centre diff. In normal drive the centre diff puts power to both front and rear axels, however if for example one of your front wheels loses traction, the centre diff then transfers all power to the front. Which means you spin the one wheel and go nowhere.

When you have it in HL, the centre diff is locked meaning that drive is 50/50 front and rear regardless of traction. The gearing however is the same as driving on road. LL is locked 50/50 but reduces your gearing greatly for different 4wd situations.

You can see this on the sand quite prominantly, if you leave it in normal drive you can still get in most soft sand entrances with heaps of momentum, slow it down however and you will be going along nicely until all of a sudden one wheel will just open up and you will stop. If you do the same thing in HL you will just drive through with little effort 90% of the time.

Hope this helps mate,

Brent

Thanks Brent , yes good help.
Now to see what she'll do.