[ringoism]

Originally Posted by NomadSK

I don't think so driving in 4H will harm your differential at moderate speeds, once engaged, it splits engine torque 50/50 between the front and rear axles. In this mode there generally isn’t any cross-axle locking unless it is manually activated. In this mode traction control also works to help modulate torque across the axles, but in some situations it won’t be enough to move a stuck vehicle. I don't have an idea about how Jimny's 4H works.

During rains, I drive in 4H mode to get more traction out of the surface and for better stability. The engine operates more efficiently in 4H mode since it doesn't need to work as hard to maintain speed. It's suitable for driving on surfaces where additional traction is needed without excessively loading on the engine.

Or am I missing something ?

Forgive me if others have answered alteady, but yes, you are unfortunately definitely missing something(s).

And many respondents here in the thread are giving bad info. For example, in suggesting that only 4Lo would cause damage, not 4Hi (no difference!). Or just taking it lightly. Or advising/ comparing with cars that have completely different systems.

Jimny has a proper 4x4 transfer case with no center differential, moderate speeds will not help anything, and any turn taken at any speed on dry pavement in any 4wd range could damage / break things. Everything needs to be checked out.

Traction control transmits power to wheels with more grip, it would do nothing to alleviate the "windup" (drivetrain binding due to unequal speeds of front/rear wheels & driveshafts during turns) which the car is definitely going to experience in a situation like this.

You should NOT be engaging 4x4 modes on merely wet roads with this kind of system, it is NOT "more efficient" and WILL place additional strains on all drivetrain components including differentials, hubs, axle shafts, cross joints, transfer case, etc.

Conventional 4x4 systems are intended for gravel, snow, sand, mud, loose dirt, and other generally slippery surfaces.

An "AWD" with some slippage allowed between front and rear drive systems is an entirely different beast, those can generally be used anywhere / anytime, and may have a separate selectable center diff lock to help in really bad conditions.

One of the first Gypsies I became familiar with in India had its 4x4 system damaged by uninformed drivers who drove in 4x4 mode on pavement.

-Eric.

[ringoism]

Originally Posted by Kosfactor

Nothing will happen to the car if driven on the road like that for sometime or even if your car has done a Bangalore to Mysore through the expressway with 4H on.

As we speak plenty of folks with Scorpio N would have kicked the vehicle into 4WD without knowing it and will be driving around like that till they sense something odd with the way gear shifts are happening

Astonishing. Please do not EVER assume it would be ok for Jimny or similar 4x4 systems to be on an expressway (OR ANY PAVEMENT) with 4x4 engaged!!!

Somehow 4x4 knob got turned to 4wd Hi when driving the Getaway across N. India the first time. I didn't notice what had happened till a half km after a turn when bad grinding sounds started coming. I think I was lucky and one of the front autolock hubs only got damaged /.started slipping. But I STILL get a weird noise whenever 4x4 is engaged now, even in slippery stuff. Works fine but that noise shouldn't be there.

Scorpio-N is again a different kind of system, iirc. Many systems have a center diff / engagement clutches (Haldex for example), and/or electronically prevent engagement till "right" speed conditions are met.

Even with some of these "different systems", specifically those with LSD-type center diffs, damage can be done above certain speeds. This is because with wear / inflation differences / brand variations, tyre diameters may vary slightly and cause differing front/rear driveshaft speeds. So clutch packs in the center diff are in a state of continuous friction which becomes intense and creates massive heat at higher speeds. Friend with an Aria 4x4 had a bad 4x4 indicator lamp, didn't realize he was in 4x4, on the highway cooked his fluid till it was literally smoking out the vents and depleting... I am pretty sure his clutch packs are toast, and AWD unlikely to grip well at this point. He had one mismatched tyre, never thought of the significance, and I'm sure most others are like him.

Lots of people change tyres in pairs, when those at one end of the car are more worn. And certain AWD systems won't like that.

Long story short, you have to follow the manual's instructions exactly, rather than a dozen strange opinions from here/ elsewhere.

Or else you must fully understand what kind of a system you have and how it works and when (if ever) those rules might be violated temporarily.

Jimny manual says no tarmac in any 4wd mode. Obey that, period. You have a right to be worried if someone has not obeyed. Especially if that's ASC staff.

Please, PLEASE don't listen to anyone saying that with Jimny it's fine / designed for this / nothing to worry.

Very possibly no damage. Jimny is lightweight, and stock tyres skinny, and thus hard to put extreme loads on drivetrain. But if they took tight turns on absolutely flat pavement with uncompromised grip, I mean... it's definitely not a good thing.

I've seen where in Mizoram pickups sometimes have to use 4Low just to get up extreme paved gradients. I've had to do that in the Getaway, too... but not for more than maybe 200 meters, and I am careful to try and disengage 4x4 prior to making any turns, else I can feel things start binding up and tyres skipping, etc. Might add that I've seen the front diff of one of those pickups opened up at the ASC, it was in horrible shape, ring and pinion just totally deformed from wear.

In your case if nothing broke in those 6km's and there are no new weird noises now and 4x4 is confirmed fully operational, then I'd not be overly concerned.

But yes, would give staff / SM a severe scolding/ warning, and yes I think it's reasonable to push for an extended warranty on drivetrain.

Having the fluids in TC/Diffs checked for metallic sheen/ changed may be good but it won't help in assessing wear on cross-joints / CV's.

-Eric

[NomadSK]

Originally Posted by ringoism

And many respondents here in the thread are giving bad info. For example, in suggesting that only 4Lo would cause damage, not 4Hi (no difference!). Or just taking it lightly. Or advising/ comparing with cars that have completely different systems.

Thanks for your insight, but it's completely related for 4H with diff locks, either front or rear. But OP never mentioned that. And I'm not sure about the 4x4 working of Jimny in 4H mode, probably it locks the front/rear differential, then its a point of concern.

Jimny has a proper 4x4 transfer case with no center differential, moderate speeds will not help anything, and any turn taken at any speed on dry pavement in any 4wd range could damage / break things. Everything needs to be checked out.

4H with open diffs won't damage anything on the bitumen pavement.

You should NOT be engaging 4x4 modes on merely wet roads with this kind of system, it is NOT "more efficient" and WILL place additional strains on all drivetrain components including differentials, hubs, axle shafts, cross joints, transfer case, etc.

As said above, 4H with open diffs doesn't create any problem, either paved or in rainy wet condition and allows for completely different wheel speeds on the same axle, meaning no wheel slip will occur while going around a corner, as the outside tyre will travel further, with better traction. In this mode it is as good as AWD. This is what my owner manual says.

[dhanushs]

Originally Posted by NomadSK

...
4H with open diffs won't damage anything on the bitumen pavement.
..

You are wrong. 4H in dry pavement (High Mu) for extended periods of time will cause driveline windup and damages.

The user manual you have uploaded is of a vehicle which has a center diff, in which it's OK and sometimes better driving with 4H on-road. In the Jimny, where there is no center diff, it behaves as 4HLc and it is NOT recommended to drive in 4H on-road.

Originally Posted by NomadSK

..4H with diff locks, either front or rear.

It doesnt matter if you have front or rear diff locks. What matters is if you have a center differential, which allows differential front and rear prop shaft speeds for on-road driving, which in the Jimny, is not the case.

[Tejas@perioimpl]

I'm late to this thread but shocked and appalled at some misinformation here.

There are no circumstances where you should be driving with either 4H or 4L on tarmac in a part time 4WD vehicle.

Just because a few folks haven't had issues doesn't make it empirical.

You will be slowly stressing out components which would lead up to a failure at a later date.

Please DO NOT advocate that it is ok to drive with 4H on tarmac.

There are times we have noticed windup issues offroad when you drive on rocks faces of mountains - this is where we use the "tyre pressure fuse" option to try to make the tyre lose grip!

Again, just because it hasn't happened to someone else, shouldn't be a yard stick that it will not happen to you. Drive train windups can be costly when things go wrong.

[arjithin]

Originally Posted by Tejas@perioimpl

There are no circumstances where you should be driving with either 4H or 4L on tarmac in a part time 4WD vehicle.

Mitsubishi Pajero/Triton/Pajero Sport etc can be considered part time 4WD right? If yes the Mitsubishi super select II system allows 4H on tarmac upto 100kmph.

Edit : attaching manual screen shot

[purohitanuj]

I am shocked to see the knowledge (or lack of) regarding Full time and Part time 4WD. I have said enough on other forums hence cannot reiterate here.

People showing a full time 4wd with central diffs and claiming the same for Jimny is outstanding.

I will paste a paragraph here:

"We need to understand that while turning any car (let’s say a right turn), the wheels on the left have to travel a longer distance than the wheels on the right. This is because of the different turning radius for the left and right wheels. Therefore, the wheels on the left must travel faster than the wheels on the right. This difference in RPM between the left and the right (a similar phenomenon exists between the front and rear wheels) is managed by a differential that allows different RPM for the wheels.

When you drive your Jimny on 4WD, the front and rear differentials are locked via the transfer case. That means that all the wheels must turn at the same RPM.
As a consequence of this, the car will naturally oppose turning. If you force the turn, the car will turn, but some wheels will skid on the ground to compensate for the difference in distance to travel.
If you are on soft terrain, like sand, snow or even on a dirt road, it would be possible for your wheels to skid without much trouble.
However, on a regular road or any hard surface that allows good friction with the tyres, this becomes a problem because the wheels are not allowed to skid. Hence, the car will tend to go straight only and avoid turning.

You can try with a toy car that has left and right wheels joined together. If you want to turn the car, the wheels must skid.
If not skidding possible, no turning. That’s why this braking effect is felt when you try to turn sharply on a regular road while driving 4WD.

So, what do you need to do/know ?
Drive your Jimny on 4WD mode only on surfaces that allow your tyres to skid easily. If the friction between your tyres and the surfaces is strong, don’t drive on 4WD because while turning, you are putting a lot of tension in the mechanism (that translates into a braking effect), which may damage your differential.

[Kosfactor]

Originally Posted by purohitanuj

I am shocked to see the knowledge (or lack of) regarding Full time and Part time 4WD. I have said enough on other forums hence cannot reiterate here.
.

Well, what if your friend borrows your Jimny, drives it on tarmac for 100 kms on 4H?!

Now you see, such things happen more often than you think. Therefore as long as your tires are stock and the vehicle is not overloaded, chances are nothing will happen.

It has happened to atleast two of our vehicles and they are doing alright, so OEMs have certainly taken such mistakes into account.

[purohitanuj]

Originally Posted by Kosfactor

Well, What if your friend borrows your Jimny , drives it on tarmac for 100 kms on 4H?!
.

In that case, he is not my friend anymore!

Just because it did not happen does not mean it will not happen.
The OEM in this case have clearly mentioned in the user manual and also provide a tag on 4WD lever. Good luck explaining this rationale while claiming warranty.

[Sheel]

Originally Posted by Kosfactor

Well, What if your friend borrows your Jimny , drives it on tarmac for 100 kms on 4H?!

.

If it's your SUV and you have to lend it and you have not explained the workings / functioning of your SUV, who is responsible?

[Vikram Arya]

Originally Posted by arjithin

Mitsubishi Pajero/Triton/Pajero Sport etc can be considered part time 4WD right? If yes the Mitsubishi super select II system allows 4H on tarmac upto 100kmph.

Edit : attaching manual screen shot
Attachment 2632946

Well, you seem to have missed an important data point.

Mitsubishi's Super Select II system comes with a Centre Differential which stays open in the "4H" mode and is locked in the "4HLc" or the "4LLc" mode and that's why in the screenshot that you have enclosed it advises you to use those modes only in "Deep Snow, Muddy, Sandy, Rocky" surfaces. The open centre differential in the 4H mode will prevent any transmission binding from happening while diving on a paved surface in the "4H" mode.

Jimny as has been mentioned by several contributors here does not have a center differential and therefore the two scenarios are as different as chalk and cheese.

I'm disappointed by comments by some contributors almost saying that it's okay to drive in 4H on a paved surface in a vehicle that does not have a centre differential.

Massive thanks to Eric, Dhanush & Dr. Tejas to set the record straight.

[MB4DI]

My humble request to all Jimny owners,

Guys your car has got Part Time 4WD system with NO center differential in it, hence engaging 4H on Tarmac is big NO. Risk of transmission windup is for real.

Only vehicles with unlocked center differentials are capable of running into 4H mode on tarmacs.

MB4DI

[ringoism]

Originally Posted by NomadSK

Thanks for your insight, but it's completely related for 4H with diff locks

No, it is definitely not, it is related to Jimny and all vehicles which share a technically similar part-time 4x4 system.

Originally Posted by NomadSK

I'm not sure about the 4x4 working of Jimny in 4H mode

Exactly the problem!

Originally Posted by NomadSK

4H with open diffs won't damage anything on the bitumen pavement.

Absolutely untrue / dangerous advice, UNLESS one also has a center diff set to unlocked mode (which Jimny does not/ cannot!).

Originally Posted by NomadSK

This is what my owner manual says.

But you do not drive a Jimny, nor a vehicle that shares its type of 4x4 system, and this was not written for such vehicles!


As others have mentioned, this is bad info/ advice here which should NEVER be regarded by anyone who cares about the longevity of their traditional part-time 4x4 vehicle, of which Jimny is but one example. Same would go for Gypsy, Bolero/Marshal/Scorpio (not N), 340/540/550 Jeeps, Safari, Xenon, Tata/M&M/Force pickups & Gurkha, old/new Thar, etc, etc...

You yourself have acknowledged that you do not know how the Gypsy 4x4 system works, and as such it would be far better to remain silent on this, you will be responsible for putting members' beloved and dearly paid for vehicles at serious risk here.

Plainly, you are getting confused between differential locks on the axles (as per Gurkha), and lockable center diffs like on Montero/Pajero/Duster/Fortuner systems, etc...

it would indeed be bad to lock ANY differential in ANY part of ANY system on dry tarmac. And ok to run on tarmac up.to specified speeds IF (and only if) there is a center diff or a Haldex-type clutch or viscous coupling or whatever.

But most important to understand here is that a Jimny/Gypsy has a simple, solid,."locked" link between front and rear axles when 4x4 is engaged. Unlike on these others mentioned, there is no diff and no 4x4 mode available which allows for differences in speeds of propeller shafts that ALWAYS occur when cornering in AWD/4WD vehicles. So things WILL bind up and stresses can be huge, and damages are by no means unlikely.

Again, does not mean you might not get lucky and avoid breakage/ excess wear in some limited case or the other, but it's definitely NOT ok.

Would urge those who do not fully understand the mechanics of these widely differing systems to refrain from further statements/ debate, as you are putting others' vehicles at risk. There are important variations on a theme here, and instructions applicable to one type of 4x4 system would often be contraindicated for another.

I've got 40+ years experience around 4x4/AWD in and out of snow-belts on a couple continents, worked as a Mechanical Engineer in the automotive field for 8-1/2 years, and know what I'm talking about, as do a few others here who have likewise contributed and stated the truth - including the manufacturers who wrote these respective manuals. It is a shame that there should even be debate about something as obvious as this.

You are of course free to do whatever you want with your own vehicle, even if it violates the manufacturer's clear instructions. In that case you pay the price, not anyone else.

My apologies for being rather "direct" here, but in a case like this where tens of thousands of rupees (or more) in driveline components are on the line, I think absolute clarity in understanding and communication is a must.

All this does make me think that perhaps MSI should be considering a more foolproof AWD system if they want mass-market / average family man appeal and usability here. I hate to think how many warranty claims will come up from these misunderstandings (/careless disobediance). That extra diff/clutch would raise MRP and/or lower FE though, and they're already having trouble on both fronts.


-Eric

[Chetan_Rao]

Extract from the JB74 user manual. Transfer lever operation is pages 5-39 through 5-44. The speed limit for an on-the-fly 2H-4H shift is 100 kmph, but that is not to be confused with the surface types it can be done on.

The bit highlighted in RED clearly mentions one SHOULD NOT be using it on pavement, dry or wet.

[HappyWheels]

Originally Posted by NomadSK

Thanks for your insight...

The image you have shared seems to be from a Pajero, which offers the best of all options with AWD and 4WD system. This is NOT the right options for a Jimny.

And please do not drive, or even recommend to anyone, to drive in 4H in a Jimny, on tarmac / surface with enough traction.

Originally Posted by arjithin

Mitsubishi Pajero/Triton/Pajero Sport etc can be considered part time 4WD right? If yes the Mitsubishi super select II system allows 4H on tarmac upto 100kmph...

For the Pajero, in 4H, which is equal to AWD system for other vehicles, there is no limitation on speed. Drive as you normally do.