4 Wheel Drive Systems: Their differences...

[mazdamazda]

um. super bump lang.

anong klaseng full-time 4wd ang sa outlander?

Full-time Symmetric AWD, same as the Rav4 and X-Trail.

[jaeger]

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What do you call the 4WD system that's full-time AWD (with torque-split system) but has a 2-speed transfer case (HI & LO) just like in the Fortuner's Torsen drivetrain and the Sorento's Borg-Warner Torque-on-demand drivetrain?

Most of the full-time AWD of the compact SUV (like CRV & Rav4) only has a torque-split system (i.e. locking center diff.) in the transfer case without the Hi & LO 2-speed gearing.

Isn't it that when you say AWD, you normally refer to a torque split system without necessarily incorporating a 2-speed transfer case, so what do you call an AWD with a 2-speed transfer case? Is there a particular term for this kind of 4WD system?
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[OTEP]

You call the Fortuner a dual-range full time system. Variants of Land Cruisers also use a similar system.

The dual-range part is what separates the men from the boys.

[nugundam93]

so would the evo then have symmetric awd? i know the impreza wrx has assymetric awd...

[OTEP]

If the default torque split between the front and rear is 50/50 then its symmetric. Otherwise its not.

GEN II Pajeros were symmetric in 4H (unlocked) mode. The GEN III is asymmetric (rear drive bias to improve handling daw).

[jaeger]

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So that's what it's called - Dual Range Full Time system. Thanks. Expert talaga si boss OTEP pagdating sa 4WD. Saludo ako.

Would you know if the series of discs which make up the viscous coupling in a full-time 4WD system - are they replaceable specially if you're a regular off-roader?

Like if I have a Fortuner and go hard-core trailing every weekend, diba there will come a time when that viscous coupling starts to slip due to wear-n-tear. Can you just change the discs or replace your entire center diff.?
(I guess if you're really into regular hard-core 4WD trailing, it's wiser to get a part-time 4WD with real 2-speed gearing, right? instead of getting a rig with dual range full-time system - is this a safe conclusion? or not neccessarily?).
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[nugundam93]

ahhh okay. thanks!

[OTEP]

Hindi naman in contact ang clutch packs kapag viscous coupling. The 'wear' occurs when the fluid is overheated and looses its viscosity. This results in reduced transmission of drive force from one blade to the other.

Solution: replace fluid. :D

Wala bang center difflock ang Fortuner so you can just go into direct-drive and bypass the center differential's effects?

[rj_tim]

e sa tucson anong klaseng AWD?

[Hayward]

Very informative and educational even for those that don't have 4X4 rigs especially when experts join in the discussion. Let us have more of this please.