[murlidar]

whereas 4WDH will snap the transmission, in entirety? Speaking from experience I presume?[/quote]
It is common knowledge that 4WDH is not be used on hard tarmac as it will affect the entire transmission.
https://dixie4wheeldrive.com/why-it-...-dry-pavement/

[purohitanuj]

Originally Posted by BlackBeard

4H indeed, not 2H...normal 2wd drive towing is a regular activity on our roads isn't it, even cars engage in it?

To be clear, you are suggesting to drive a parttime 4WD on road, towing a car, taking turns?
Towing in 2wdL *may* break an axle (3000-4000 INR) item. While what your suggesting *will* damage either the diffs, or tcase, or transmission. (20K to 3L INR)

I guess you are talking with respect to a "full time 4x4"(Fortuner); are you?

Everyone is free to set their own budget.

[BlackBeard]

Originally Posted by murlidar

It is common knowledge that 4WDH is not be used on hard tarmac as it will affect the entire transmission.

What is more common knowledge is NOT TO USE 2WDL, if it was safe & usable the vehicle manufacturer would have recommended that.

Towing a heavier vehicle uphill
Do you agree, there are chances of wheel slippage and loss of traction while doing so? The link you referred says NOT TO USE in dry pavement i.e where there are less possibilities of loss of traction and wheel slippage, However 4WDH can certainly be engaged in slippery conditions even on hard ground.

Originally Posted by purohitanuj

Everyone is free to set their own budget.

I have not suggested anything about budget or cost of repairs..etc
From the point of safety it is NOT recommended to use 2WDL least of all while towing and going uphill simultaneously!

BTW, the post 2016 Fortuner is also part time 4WD unlike its predecessor.

These discussions have been going on for years, many of us have done it in REAL life.
https://www.team-bhp.com/forum/4x4-t...hlight=towing& (Towing a broken down 4x4)

[purohitanuj]

Originally Posted by BlackBeard

From the point of safety it is NOT recommended to use 2WDL least of all while towing and going uphill simultaneously!

I have added towing as a use case and in an earlier post, have added my inputs to tow on level road.

[BlackBeard]

Has anybody ever driven a 4WD vehicle on 2WD-FWD?
If so, I would like to know the experience and feedback!

[Samurai]

Originally Posted by BlackBeard

Has anybody ever driven a 4WD vehicle on 2WD-FWD?
If so, I would like to know the experience and feedback!

For that to happen in a part-time 4WD, you need a vehicle with fully floating rear axle equipped with freewheeling hubs.

That said, most AWDs are front wheel drive in 2WD, until the rear becomes active or locked. It is like driving any front wheel drive car.

[dhanushs]

Originally Posted by purohitanuj

To be clear, you are suggesting to drive a parttime 4WD on road, towing a car, taking turns?
Towing in 2wdL *may* break an axle (3000-4000 INR) item. While what your suggesting *will* damage either the diffs, or tcase, or transmission. (20K to 3L INR)

With so much engineering going into developing 4WD systems which enable vehicles to traverse multiple terrain, I'm surprised that manufactuers have not considered this particulat situation: of a high frictional co-efficient, high gradient. If yes, they themselves would've provided a 2WD(L).. right?.. it was soo simple.

Let me mention this one more time.. Please dont worry too much about driveline windup. Like I said, manufactuers do enough abuse tests, to accomodate for real world use cases. Even in extreme cases windup will not cause a complete vehicle breakdown in 4x4 trails, where as breaking an axle will.

Originally Posted by murlidar

Snaping rear axle is a very remote possibility(engine stalling may be earlier) but one thing you are certainly assured without doubt is to snap your transmission if you drive 4WD high on tarmac as suggested by you.

Well, in my past 12+ years of 4 wheel driving, i have broken enough axles which teach me otherwise.

[BlackBeard]

Originally Posted by Samurai

For that to happen in a part-time 4WD, you need a vehicle with fully floating rear axle equipped with freewheeling hubs.

OR broken rear axle which makes the RWD vehicle undriveable in which case 4WD must be engaged which effectively makes the vehicle 2WD-FWD.
I have experienced it on a Mahindra jeep, vehicle was driven 7-8 kms on road very slowly to the garage for repair.

[Samurai]

Originally Posted by BlackBeard

OR broken rear axle which makes the RWD vehicle undriveable in which case 4WD must be engaged which effectively makes the vehicle 2WD-FWD.

Do you mean rear propeller shaft? I wonder how you could drive with a broken axle.

[BlackBeard]

Axle, one of the rear axles got cut.

Vehicle had a LSD installed in the rear.

[NomadSK]

Originally Posted by Samurai

That said, most AWDs are front wheel drive in 2WD, until the rear becomes active or locked. It is like driving any front wheel drive car.

Mine RAV4 AWD is RWD in normal scenario, the moment I stomp on the accelerator pedal, the FWD comes into play, I can see that on the display. Since all wheels are connected to the gear box all the time, I get good traction on asphalt during rains. But it's worthless to use in sand for serious off-roading, due to lack of diff-locks. Soft off-roading is still possible.

[Kosfactor]

Originally Posted by BlackBeard

Axle, one of the rear axles got cut.

Vehicle had a LSD installed in the rear.

How would the vehicle drive with broken rear axle is the question that Samurai wanted to ask I think (Usually Jeeps have SFRA) - if it happens on the move, rear wheel would overtake the vehicle and go ahead

Which would be inconvenient to say the least when you are on a climb, having to chase a wheel on foot that`s going downhill - not good.

So the general recommendation should be to use 4WD - Low range when needed, nothing will go wrong.

[BlackBeard]

Originally Posted by Kosfactor

How would the vehicle drive with broken rear axle is the question that Samurai wanted to ask I think (Usually Jeeps have SFRA) - if it happens on the move, rear wheel would overtake the vehicle and go ahead

Which would be inconvenient to say the least when you are on a climb, having to chase a wheel on foot that`s going downhill - not good.

You are assuming this was usual jeep with SFRA.
Please read my previous post (No.53) regarding the scenario.

Do look up on how a LSD operates!

[Tejas@perioimpl]

Originally Posted by BlackBeard

Has anybody ever driven a 4WD vehicle on 2WD-FWD?
If so, I would like to know the experience and feedback!

Me! In my old modified jeep with fully floating rear axle (FC van axle). Rear snapped clean without the pieces jamming. Slotted to 4H and drove back home without issues.

If your break is not clean you might face binding of the broken axles.

Originally Posted by dhanushs

With so much engineering going into developing 4WD systems which enable vehicles to traverse multiple terrain, I'm surprised that manufactuers have not considered this particulat situation: of a high frictional co-efficient, high gradient. If yes, they themselves would've provided a 2WD(L).. right?.. it was soo simple.

Providing 2L would mean more parts to not let the front and rear shafts to lock in 2L and then another system to lock the front and rear shafts in 4L. So TC size would increase - as per my understanding. Is it worth the additional development would be the question for the manufacturer to cater to a very minuscule user base for 2L?

Let me mention this one more time.. Please dont worry too much about driveline windup. Like I said, manufactuers do enough abuse tests, to accomodate for real world use cases. Even in extreme cases windup will not cause a complete vehicle breakdown in 4x4 trails, where as breaking an axle will.

I wouldn't generalise this statement. I'd be very worried about messing up my TC in a windup and pay a big cost in repairs/replacement.

Windup happens too far often from what I have heard and seen on forums where 4wd uneducated folks drive in 4H on tarmac

For others:

In terms of the 2L, look at Atlas transfer cases that come in some trucks where there is a provision for driving the trucks on gradients in 2L (RWD)

[dhanushs]

Originally Posted by Tejas@perioimpl

...

I wouldn't generalise this statement. I'd be very worried about messing up my TC in a windup and pay a big cost in repairs/replacement.

Windup happens too far often from what I have heard and seen on forums where 4wd uneducated folks drive in 4H on tarmac

Tejas, This statement was for the OP and in the context of the thread. OP was worried about using 4L even very very rarely in real use case scenarios. Hence I said not to worry.

Originally Posted by dhanushs

@OP - Your problem of not able to engage 4L in tarmac/grippy surfaces is very relvant. There is a bit of windup caused and continuous running will wear out your mechanicals.
...

Like I've said before.. Windup is real. But, will be a cause of concern.. but only for a person who abuses it. It's no fun steering your 4x4 in hard asphalt, so unless the user intentionally abuses or has utter lack of knowledge there is no real point in running 4WD(Lock) on grippy surfaces..

For those rare scenarios like one Sandakhpu, its fine.