Diff locks (operation)

[Miki]

Yes, I have the information from the Ineos console, and I have two batteries

I think some external measuring and attention to the voltages when the errors occur would be a good thing to examine.

I am somewhat confused by what I have read regarding the charging rates of batteries on the Grenny.
Surely the voltage is @ 14.5V and the CTEK is dealing with the charge rates ??
I confess to not being 'aufait' with this new breed of intelligent alternators and complex battery systems.

 

[ADVAW8S]

Here is recent video showcasing the Grenadier offroad with a instructor. The instructor is filming while the journalist is driving. You will see, at just after the 5 minute mark, the instructor begin the diff lock process. He says the diff can be turned on driving as long as you are going below 15 mph. You will also see he is struggling to get them to engage. It looks like the front never do and the video is edited. Listen closely and you will hear instructor say I don't know why it didn't work but we didn't need them anyways.

View: https://youtu.be/MMRmMrxFgKc

 

[rovie]

From my point of view, the following important advice to all those who have and use diff locks:

If you have switched on the rear and front differential locks off-road and then want to get out of the car to clarify how to continue off-road, do not switch off the engine under any circumstances.
When you start the engine again, the locks do not switch on again (the indicator lights on the switches flash).

You will have to drive a few metres for the lights to go out. Only then can you switch the diff locks on again.

However, this can be really problematic in off-road terrain. Depending on how the ground continues. On a difficult mountain pass road it can also be very dangerous.

INEOS is aware of the problem and will hopefully find a solution.

I can imagine that this also means a software adjustment.

 

[ECrider]

From my point of view, the following important advice to all those who have and use diff locks:

If you have switched on the rear and front differential locks off-road and then want to get out of the car to clarify how to continue off-road, do not switch off the engine under any circumstances.
When you start the engine again, the locks do not switch on again (the indicator lights on the switches flash).

You will have to drive a few metres for the lights to go out. Only then can you switch the diff locks on again.

However, this can be really problematic in off-road terrain. Depending on how the ground continues. On a difficult mountain pass road it can also be very dangerous.

INEOS is aware of the problem and will hopefully find a solution.

I can imagine that this also means a software adjustment.

Thanks Rovie, interesting info.

Hoping Dcpu or Jean M can come up with one of those Gwagon army spec over ride switches more and more.

 

[DCPU]

There's really only one answer in my mind ~ strip out all the electronic/software logic and rely on user training.

It seems a classic case of a clever software engineer incorporating a function into a control system whilst never actually understanding the operating philosophy behind it.

I'd like to see some wiring diagrams of how the diffs are activated. In my head, given that the base Eaton e lockers have no such logic then it should be possible to orphan the Ineos system in a passive state and activate the e lockers with a simple toggle switch.

There's probably much more to consider but the complication that springs to mind is how traction control will react. In theory, if there's no differential wheelspin seen at any wheel station then there's no requirement but then there's speed over the ground to consider...

 

[AnD3rew]

View: https://youtube.com/shorts/Ad-UCZelHvA?si=1W1mAYN6qkkx_ivV
Interesting little short from Ronny Dahl. As I understand it, this will apply to the Grenadier as well. Locking the rear diff means that traction control is disabled on both front and rear axles. If you are in a situation where you have centre and rear diff locked and you lose traction on one front wheel you may end up stuck because effectively all the power/torque is going to that one wheel. In that case you will need to either engage the front locker, or disengage the rear in order tobget your traction control back.

 

[Shopkeep]

View: https://youtube.com/shorts/Ad-UCZelHvA?si=1W1mAYN6qkkx_ivV
Interesting little short from Ronny Dahl. As I understand it, this will apply to the Grenadier as well. Locking the rear diff means that traction control is disabled on both front and rear axles. If you are in a situation where you have centre and rear diff locked and you lose traction on one front wheel you may end up stuck because effectively all the power/torque is going to that one wheel. In that case you will need to either engage the front locker, or disengage the rear in order tobget your traction control back.

If centre diff is locked 50% of power still goes to rear?

 

[Krabby]

Yes. By locking the center you are splitting the power 50 front and 50 rear.

 

[James]

View: https://youtube.com/shorts/Ad-UCZelHvA?si=1W1mAYN6qkkx_ivV
Interesting little short from Ronny Dahl. As I understand it, this will apply to the Grenadier as well. Locking the rear diff means that traction control is disabled on both front and rear axles. If you are in a situation where you have centre and rear diff locked and you lose traction on one front wheel you may end up stuck because effectively all the power/torque is going to that one wheel. In that case you will need to either engage the front locker, or disengage the rear in order tobget your traction control back.

Agree with shopkeep, I think the centre diff fixes this, youll still have both back wheels tractable. front diff (or other electronic aid) could restore at least 1 wheel traction on the front (presume one is spinning in air on on slippery surface). But the centre lock will prevent too much spinning on the front axle, because it limits the total rotations to whatever the rear axle total is.

 

[Robert T]

I found this interesting video on how the diffs work. The video is in German but with cc auto translate to English I think I got the main points. Per the last segment of the video they seem to show that the diffs unlock instantly.

View: https://youtu.be/_Mvo-y6paC8?si=0bGI-0xsZfm0qui8

 

[MileHigh]

I found this interesting video on how the diffs work. The video is in German but with cc auto translate to English I think I got the main points. Per the last segment of the video they seem to show that the diffs unlock instantly.

View: https://youtu.be/_Mvo-y6paC8?si=0bGI-0xsZfm0qui8

Did they have the electronic traction aids turned off? Electronic stability control should work in 4hi, right?

 

[Michael H.]

Did they have the electronic traction aids turned off? Electronic stability control should work in 4hi, right?

I too was wondering why traction control did not kick in.

 

[MileHigh]

"4

"4hi" is the normal mode of operation....

For you people that live in Boring, Flat land…

 

[Tinerfeño]

Yes. By locking the center you are splitting the power 50 front and 50 rear.

No. Power is revolutions x torque. Center diff locked both shafts from transfer box have same revolutions but if front is on ice and rear is on gravel the torques are different and so are the power intakes to the axles. In extereme case (one wheel in air, no axle lokcers) all power may be transferred to one axle despite CDL is on.

 

[DenisM]

For you people that live in Boring, Flat land…

I deleted my post because I'd misread the previous comments... I agree about the Flat Lander... but I am grateful that I've been able to take delivery of my Grenadier before I become a Flat-liner!
In all my years travelling back and forth across the Pacific to the USA as part of my job, I regret that I never got to visit Coloradoother than to occasionally fly over the mountains on a crystal clear day in winter en route to the east coast... a truly magnificent spectacle

 

[bigleonski]

For you people that live in Boring, Flat land…

Is that code for Australia?? The flattest continent on earth. Shame on you, far from boring.

 

[Tazzieman]

Is that code for Australia?? The flattest continent on earth. Shame on you, far from boring.

Agree.

 

[stickshifter]

I found this interesting video on how the diffs work. The video is in German but with cc auto translate to English I think I got the main points. Per the last segment of the video they seem to show that the diffs unlock instantly.

View: https://youtu.be/_Mvo-y6paC8?si=0bGI-0xsZfm0qui8

I don't have any experience with full-time 4-wheel drive off-road 4x4 vehicles. All my 4x4s have been part-time 4-wheel drive, with a two-speed transfer case, with the default mode for on-road driving being rear-wheel drive. I have also owned all-wheel drive sedans from Audi, and those are, of course, a very different set-up, designed for very different use.

I was surprised to see how easily the Gren lost traction in "full-time 4-wheel drive" mode. At 3:30 in the video, they have the Gren in its default on-road driving mode (all three diffs open) - which is its "all-wheel drive" or "full-time 4-wheel drive" mode. They put one wheel on a roller, and the Gren could not move. This was easily resolved, by locking the center diff, and putting the vehicle in true 4-wheel drive. But still, I was surprised that the "all-wheel drive" mode didn't fare better. To get off a single roller, an all-wheel drive set-up would need some sort of traction control - a computer that recognizes that one wheel is spinning, and redirects power to other wheels. I thought the Gren had basic traction control in its "all-wheel drive" mode. Am I wrong?

One of the main reasons I got interested in the Gren was its advertised lack of electronics - so I'm not going to complain about a lack of electronics here. But according to the reviews I have read - the Gren does have traction control. So what is going on in this test?

It would also be a bit ironic that - here in North America - we are getting a vehicle loaded with computer-controlled active safety systems, but we aren't getting a vehicle that has an effective traction control system in the on-road driving mode.

I hope I am missing something, so I look forward to being set-straight.

EDIT: Bottom line - I am wondering what the advantage is of having "all-wheel drive" if it loses traction so easily. When I compare the Gren to other true off-roaders, one of its advantages is having "all-wheel drive" - but this test makes me think that I'll be shifting in and out of 4-wheel drive during winter driving, just like I have always done in my Jeeps and pickup trucks.

 

[Tom109]

EDIT: Bottom line - I am wondering what the advantage is of having "all-wheel drive" if it loses traction so easily. When I compare the Gren to other true off-roaders, one of its advantages is having "all-wheel drive" - but this test makes me think that I'll be shifting in and out of 4-wheel drive during winter driving, just like I have always done in my Jeeps and pickup trucks.

The advantage is not rear wheel drive. Part time 4-wheel drive resulting in rear wheel drive for 90% of use case is something I would never buy. I have only owned full time 4wd - 1990's Discoveries and Range Rover Classics - and that video shows how the system should work. You don't have to shift in/out of 4wd during winter driving (like a part-time-4wd). If conditions seriously deteriorate, lock the center diff.

 

[stickshifter]

The advantage is not rear wheel drive. Part time 4-wheel drive resulting in rear wheel drive for 90% of use case is something I would never buy. I have only owned full time 4wd - 1990's Discoveries and Range Rover Classics - and that video shows how the system should work. You don't have to shift in/out of 4wd during winter driving (like a part-time-4wd). If conditions seriously deteriorate, lock the center diff.

Shifting in and out of 4-wheel drive in a part-time 4-wheel drive is equivalent to locking the center diff in a full-time 4-wheel drive.

What the video showed at 3:30 is that while in "full-time 4-wheel drive" the Gren loses all traction when one tire loses traction.

So I'm having trouble seeing the advantage of "full-time 4-wheel drive" when compared to part-time four-wheel drive. In both types of vehicles, it seems that you have to shift while driving in low-traction conditions on-road:

In the part-time 4-wheel drive vehicle, you have to shift into 4-wheel drive, which splits power 50/50 front and rear.

In the full-time 4-wheel drive vehicle you have to lock your center differential, which splits power 50/50 front and rear.

Honest question: can someone who understands the mechanics of the Grenadier's full-time 4-wheel drive system explain under what conditions it will provide the equivalent of "all-wheel drive", and why it was immobilized by having one tire on a no-traction surface. Thanks.