[Raosaheb Desai]

Originally Posted by Raosaheb Desai

Note from the Team-BHP Support Team: Please read the previous posts before making a comment that has no relevance to the discussion.

Yep,
My ignorance.I should have read page 2.

[mayankjha1806]

Originally Posted by Manuuj

By the way can anyone explain to me what a front differential tube is?!

Looks like the front differential tube is an open tube so the differential isn't sealed tight and can breathe. Its the vent so that when the air heats up it has a place to breathe

This is really, getting information first hand from the owner so as we are not making assumptions and possible avoids needless comments on Manufacturer and the owner.

[Manuuj]

I had written a reply to Navanshu asking him for some more details, the email is reproduced below in bold:

Ive also written to Toyota asking for clarity on the issue. Will let u know as soon as i know anything. A number of other Fortuner owners are keenly following this by the way. I have even posted on the wall of the Facebook Toyota Fortuner page and customer care also asking for an explanation.

It would be a great help if you would shed some clarity on the circumstances of the incident also. (speed of car, condition of road..tarmac/slush etc, transmission ..4H, 4HL etc, present mileage, last serviced?)

Also an accurate description of the whole incident will be helpful.
What did the steering feel like, were the brakes locked?

By the way have you taken the vehicle offroad into water and slush? and if yes did u get the propeller shaft (rear and front) bearings greasing done afterwards?

All the best!


I just received a reply from him that is reproduced below:

Manuj,

The car was running @ 110 km/hr and the road was good. The car was serviced about 10 days before the incident from MGF. And it was running on 4H. It has done a little more than 21000 Kms.
I have never gone off road with this car. I have used it only on highways.
I was travelling at a speed on 110km/hr and all of a sudden there was a very strong jerk and there was lot of noise in the car. I applied brakes, but the car dint stop and after a second the car came to a halt. I just concentrated on the steering to ensure it did not go off the road. And when I got down of the car there are nauseating smell of the burnt rubber and I could see pieces of rubber all over on the road. Then I saw the long trail of the skidding tyres.
I again got into the car and started the engine and tried to move the car in the fron or the back, but it did not move.
Then I called the Toyota guys and they took the vehicle away.
If you need to know anything else, pl do let me know.

Thanks !!

Neither he or I have heard back from Toyota yet to the CAUSE of the mishap.

[mxx]

Any updates on this? regarding what is the diagnosis, or reply from toyota

[ssh1979]

Firstly @Manuuj thanks for connecting Toyota, the victim and us enthsiasts together

Now, I know T-Fort is a full time 4WD, but what does the owner mean when he says 4H? Surely the diff. wasn't locked? Can some owner explain the displays on the MFD with respect to engaging/dis-engaging diff lock?

My (possibly premature) comment would be that 110 on 4H is not a recommended speed.

[wilful]

Originally Posted by ssh1979

Firstly @Manuuj thanks for connecting Toyota, the victim and us enthsiasts together

Now, I know T-Fort is a full time 4WD, but what does the owner mean when he says 4H? Surely the diff. wasn't locked? Can some owner explain the displays on the MFD with respect to engaging/dis-engaging diff lock?

My (possibly premature) comment would be that 110 on 4H is not a recommended speed.

Courtesy Wiki Answers

"The Fortuner comes equipped with Full time 4x4, Torsen (torque sensing) limited slip differential and a dual ratio (high / low) transfer case. The diff is lockable too.
4x4 Drive Options:
Broadly, there are four options on the transfer box (smaller gear lever).

H : Default mode. Running in all time 4x4 with the center diff unlocked. This is what you will use 99% of the time. For tarmac use.
HL : 4x4 with center diff locked. 50:50 torque between the front & rear axles. Do NOT use this mode on tarmac (you will ruin the drivetrain). Best in slush, sand etc.
LL : 4x4, center diff locked, low ratio. Use in extreme offroad applications. Only crawling speeds possible.
N : Neutral. No drive provided to the front or rear wheels. Purpose is to serve as a bridge between High & Low ratio shifts."

Looks like he was on the right mode for tarmac.

On a more humorous note - ummmm... would Tata or Mahindra get a similar kind of UDRS I wonder.

[Spitfire]

Originally Posted by ssh1979

Now, I know T-Fort is a full time 4WD, but what does the owner mean when he says 4H? Surely the diff. wasn't locked? Can some owner explain the displays on the MFD with respect to engaging/dis-engaging diff lock?

My (possibly premature) comment would be that 110 on 4H is not a recommended speed.

When it is all time 4WD means the differentials are always locked.

So its always 4x (x == H,HL,LL) for Toyota Fotruner.

Here
H == Normal driving.
HL == Actual High as we* know it.
LL == Actual Low as we* know it.

We == the average 4WD guy like me.

We don't have a H in our vintage contraptions.

I believe 4H here is the right slot to be in while doing highway runs.

What you are talking would be LL, which is for offroad only. And HL for medium speeds offroading.

PS: I am no Fortuner owner. General Knowledge and a little bit of driving one around.

[ssh1979]

Guess we are going here.

@Spitfire 4HL and 4LL are the centre diff-locked modes. 4H is the full time 4 wheel drive mode, centre diff-unlocked (normal situations).

I was referring to the 4HL mode where I mentioned driving speeds of 110 (and the mode itself, while on tarmac) is not recommended.

[nilanjanray]

4H is for normal use.

4HL for off-tarmac use. Good idea to use 4HL whenever one goes off tarmac - recommended by Andrew St. Pierre.

4LL for offroading situations that need the low range extra torque.

The Fortuner manual describes what can be done (where to use, speed limits etc.) in which mode. However, it is not at all comprehensive - an owner/driver without proper knowledge might end up using the wrong mode.

The Fortuner driver-side sun visor back has info on how to use HL and LL.

[Monaro CV8]

^^
I second that.
A few things I learnt at the boot camp:
4LL mode to be used for steep inclines and declines, specially when the road surface is not firm.
Actually used it in such situation.
4HL mode to be used in slushy surfaces.

[nilanjanray]

Originally Posted by Monaro CV8

^^
I second that.
A few things I learnt at the boot camp:
4LL mode to be used for steep inclines and declines, specially when the road surface is not firm.
Actually used it in such situation.
4HL mode to be used in slushy surfaces.

Yes, I am no expert, but where momentum is required, use HL or higher LL gear (e.g. slushy terrain where you have to keep moving - 3rd LL depending on terrain, and sand - 2nd/3rd HL). where extra torque is required or crawling is required, use 4LL - subject to proper terrain. Tyre pressure is the other variable (not including driver skill and tyres).

Some folks - say drivers without knowledge of offroading basics - might be tempted to play around with the second, smaller gear (as some folks put it) once in a while. Wonder what invisible damage happens to those vehicles with everyone being blissfully unaware till something conks off. Dangerous to buy a used 4WD vehicle unless the previous owner is known.

[dkaile]

This is indeed a disturbing, even if a one off case, for all Fortuner owners. We need to get to the root of the issue as to what caused this, whether it was driver/co-passenger error or something more sinister!

[BBR_SHR]

This issue happened at 21K on the ODO after 10 days of a service. That makes me wonder how has the car been driven during these 21 thousand kilometers. Not easy to find what is at fault. Similar to an Air Crash investigation.

[Manuuj]

Originally Posted by mxx

Any updates on this? regarding what is the diagnosis, or reply from toyota

No updates yet from either the owner or Toyota so far. I shall try to contact both again today.

Originally Posted by ssh1979

Firstly @Manuuj thanks for connecting Toyota, the victim and us enthsiasts together

Now, I know T-Fort is a full time 4WD, but what does the owner mean when he says 4H? Surely the diff. wasn't locked? Can some owner explain the displays on the MFD with respect to engaging/dis-engaging diff lock?

My (possibly premature) comment would be that 110 on 4H is not a recommended speed.

You are welcome ssh1979! As a Fortuner owner i am a bit concerned about this occurrence but somehow feel it may not be due to any manufacturing defect. The reason i say this is that there are 15,000 Fortuners on Indian roads and this the ONLY instance that i have heard of something like this happening.

The Fortuner is a full time Four Wheel Drive Vehicle (4WD) or permanent 4WD not to be confused with part time 4WD. This is a system that powers all four wheels at all times and it can be used full time on all surfaces including pavement. The additional feature of a differential incorporated into the transfer case makes it possible to use 4WD all the time.

2WD is not available, only part time 4WD offers that option..like in a Mitsubishi Pajero. Each tire creates about 25% of the available torque when the ground is level with a uniform surface. Driver has a choice of:

4H - "4-High" that's your every day setting.
4HL - High range with Centre diff locked
N- Neutral (Towing /Winching)
4LL- Low Range with Ceter Diff Locked for situations when hi Torque (not high Traction) are required.

Full time 4WD vehicles work very well on-road and are very capable off-road.

When 4LL is selected the wheels create substantially more torque than in 4H/4HL - at the same time the vehicle moves at substantially slower speeds.

Important: "4LL" does not create more traction - it creates more torque at slower speeds and that can be detrimental when the ground is slippery. Slipping tires are more likely in "low" than in "high"! On snowy, icy roads "low" would be a bad choice - some really deep snow, slush or mud however, puts up so much resistance that "low" is needed to push forward. You see, using 4WD is not an easy task.

The point i am trying to make here before you wonder why i am going off topic is that anyone who does not know all this can severely harm their vehicle unknowingly if not fully conversant with these facts. Even a small drive at higher than normal speeds in 4HL (Center Diff Locked) can harm the drive shaft which can fail unexpectedly at a later stage.


Getting back on topic the Owner of this Fortuner claims that he was in the right mode (4H) at the time of the mishap.

I shall as i said before try to contact both parties and present you with whatever i learn asap.

[Monaro CV8]

Originally Posted by Manuuj

No updates yet from either the owner or Toyota so far. I shall try to contact both again today.

Hi manuuj,
Have you heard from either parties yet ?
Quite curious to see what Toyota SC has to deduce.