Diff locks or not?

[To]

Even if not necessary for keeping traction it is good practice to switch the centre diff lock on while driving on loose ground in Low gear mode (having high torque available).

The reason behind this are thin plates behind the diff gears. The diff gears will be pushed apart by the torque because they are helical gears. They press hard against these plates while spinning. That causes a high wear of them. By locking the center diff and let the tyres do the balancing, the helical gears do not spin what equals zero wear.

Cheers
AWo

Are there any photos or videos where exactly this is pictured with the plates? As far as I know, no manufacturer makes corresponding user specifications.

 

[DCPU]

Are there any photos or videos where exactly this is pictured with the plates? As far as I know, no manufacturer makes corresponding user specifications.

Again, depending on the engineering how relevant to Ineos but Ian Ashcroft's (a well respected transmission builder in Landrover circles) advise on the topic:

"A little background on the LT230 centre diff. The centre diff is there to allow the props to turn at different speeds when cornering to stop drivetrain wind up. The speed difference is quite small and the centre diff gears are only designed to cope with these low speeds. If you are Off Road on snow or ice and you get wheelspin from one front wheel, what will happen is the rear prop will not be moving, the front will thus be going double speed, this means the small centre diff gears will be spinning like fury and after a matter of only a few seconds the planet gears will friction weld to the cross pins and the gears will fail etc. Of course in this situation the centre diff should be locked to avoid failure."

 

[AWo]

I have got 75 % Torsen diffs as rear ant front locks in my Defender. It works really well. There are people who do not like them in the front, but I never had more problems with the steering than maybe a little input if I accelerate hard. On the other hand it’s an absolute no brainer in light to medium off-road driving. For the hard stuff an 100 %airlockrt might be best

I use them in the rear and center in both Defenders. In the center not for the Torsen as such but more to get rid of another maintenance task. This and a stiffer shaft jack did it for the LT230.

In the front it is fine if you have a lower TBR.

Cheers
AWo

 

[bemax]

I use them in the rear and center in both Defenders. In the center not for the Torsen as such but more to get rid of another maintenance task. This and a stiffer shaft jack did it for the LT230.

In the front it is fine if you have a lower TBR.

Cheers
AWo

TBR?

 

[ADVAW8S]

Again, depending on the engineering how relevant to Ineos but Ian Ashcroft's (a well respected transmission builder in Landrover circles) advise on the topic:

"A little background on the LT230 centre diff. The centre diff is there to allow the props to turn at different speeds when cornering to stop drivetrain wind up. The speed difference is quite small and the centre diff gears are only designed to cope with these low speeds. If you are Off Road on snow or ice and you get wheelspin from one front wheel, what will happen is the rear prop will not be moving, the front will thus be going double speed, this means the small centre diff gears will be spinning like fury and after a matter of only a few seconds the planet gears will friction weld to the cross pins and the gears will fail etc. Of course in this situation the centre diff should be locked to avoid failure."

View attachment 7804997View attachment 7804998

If I am going over a mountain pass with heavy snow on the paved road, then does locking the center diff makes sense? There is no pavement to be seen just snow and speed is around 35mph. Also, are we able to lock the center diff on the fly in high?

 

[DCPU]

My default answer would be to say yes and then feel how your vehicle is driving. If you are getting transmission wind up you should be able to feel it through how the vehicle is handling.

Not sure about locking on the fly.

Edit: I've assumed the heavy snow has fallen and that's what you are driving on.

 

[DaveB]

The Eaton e locker as an aftermarket product does seem to be entirely electrically operated, however Ineos seem to have implemented it into the Grenadier with a logic tree/functionality that is controlled by electronics and various parameters are set that govern the activating, enabling, initiating and the deactivating, disabling, disengaging or inhibiting from operation as a series of sub systems.

Yes but if they used an air locker they would have exactly the same functions
I think a lot of it is due to the switch placement, which is accessible easily to the front passenger and possibly even the rear passenger.
I think most manufacturers don't allow the rear locker to work until you are in 4L, which also locks the centre diff, as most are only 2WD before 4H or 4L are selected

 

[DaveB]

If I am going over a mountain pass with heavy snow on the paved road, then does locking the center diff makes sense? There is no pavement to be seen just snow and speed is around 35mph. Also, are we able to lock the center diff on the fly in high?

You have to be in neutral to lock the centre diff
It doesn't have synchro

 

[bigleonski]

You have to be in neutral to lock the centre diff
It doesn't have synchro

Assuming your comment is not talking about front and rear lockers, then surely that's not right? Most (or should I say all) vehicles can lock the centre diff in high on the fly up to about 100km/hr. That's a huge downside in my view, particularly in sand.
Moving from high to low and vice versa I understand, but not just locking the centre diff in a constant high range 4wd.

 

[stickshifter]

Assuming your comment is not talking about front and rear lockers, then surely that's not right? Most (or should I say all) vehicles can lock the centre diff in high on the fly up to about 100km/hr. That's a huge downside in my view, particularly in sand.
Moving from high to low and vice versa I understand, but not just locking the centre diff in a constant high range 4wd.

I agree - this is rather unusual, and not quite on par with the competition. Locking the center diff is equivalent to shifting from 2-hi to 4-hi, and all modern 4x4s allow this on the fly up to roughly 50 or 60 mph (depending on vehicle manufacturer). In older 4x4s, you had to come to a stop, get out and manually lock the front hubs, and then shift the transfer case lever from 2-hi to 4-hi; if your hubs were locked in advance, you still had to come to a stop to shift the transfer case.

In contrast, I have never owned a vehicle that can shift from 4-hi to 4-lo on the fly; that typically results in massive damage to gears in the transfer case. Standard practice in my old Jeeps, old Landcruiser, newer Jeep, old Cummins truck, old Toyota pickup, and new Toyota pickup, is to come to a complete stop, and shift into 4-lo. You might have to inch it forward to get the gears to engage while shifting, but you do that carefully, with a very light touch on the accelerator.

 

[DaveB]

Assuming your comment is not talking about front and rear lockers, then surely that's not right? Most (or should I say all) vehicles can lock the centre diff in high on the fly up to about 100km/hr. That's a huge downside in my view, particularly in sand.
Moving from high to low and vice versa I understand, but not just locking the centre diff in a constant high range 4wd.

They state it many times you have to be in neutral to lock the centre diff
you can change from high to low unlocked up to whatever speed is not stupid.
Why would you not already have the centre diff locked on sand???
I can't think of any disadvantages unless the sand was very hard packed

 

[stickshifter]

They state it many times you have to be in neutral to lock the centre diff
you can change from high to low unlocked up to whatever speed is not stupid.
Why would you not already have the centre diff locked on sand???
I can't think of any disadvantages unless the sand was very hard packed

I think the disadvantage is under a circumstance he described: you are driving on a snowy road and all seems fine driving with the center diff unlocked (in the Grenadier, you are essentially in all-wheel drive in this mode, which should be good enough for most low-traction on-road situations), but then conditions begin to deteriorate, and you want to lock the center diff to get into true 4-wheel drive, but you don't want to come to a stop first. In my older 4x4s I faced a similar problem quite regularly, and you had to find a safe place to pull over to get into 4-wheel drive - not always safe or easy during a snow storm with limited visibility or on a highway with no shoulder or exits close by. And even if there is a shoulder to pull onto, there is a big concern that you will get rear-ended if you stop on the shoulder (poor visibility during a snow storm, and a driver just sees your tail lights, and thinks you are in the forward moving lane in front of them; they think they are following your lights, but they plow into your stopped vehicle at full speed).

There is no disadvantage with the Grenadier's system in most 4-wheel drive scenarios (i.e. off-road scenarios) when you know in advance that you want to lock the center diff, or you are off-road and there is no traffic bearing down on you in a limited visibility situation (as described above). Then - at your leisure - you can stop - pull on the lever - and off you go.

 

[bigleonski]

They state it many times you have to be in neutral to lock the centre diff
you can change from high to low unlocked up to whatever speed is not stupid.
Why would you not already have the centre diff locked on sand???
I can't think of any disadvantages unless the sand was very hard packed

Have you ever driven a constant 4wd in sand Dave. The only time the centre diff is locked is when it starts to get a lot soft, otherwise it's just like driving on the road in a constant 4wd (like the IG). For example on a week long trip to Fraser Island traveling the entire island I reckon I'll have the cruiser centre diff locked for about half an hour tops - across the cuttings and across Ngkala Rocks. Maybe longer on some of the inland tracks. Even most cuttings are done without the CD locked, but there are times when it's a good idea to engage it if it's looking a bit soft up ahead or the inland tracks get a bit gnarly. If you have to stop to do that I can imagine there are times when that could get messy.

Another example would be on an outback road that has had some rain where you are traveling without the CDL and come across a muddy or wet section and you want to engage the CDL to give you a bit more stability or in case it got a bit soft.

 

[Hannes01]

As with all 4x4s that I have owned so far, I will - when the vehicle is here - try out all the different options to see how I can shift something and when. with a bit of feeling and the right speed, it is usually possible to switch something on and off

 

[stickshifter]

Overall - I think the 4x4 set-up in the Grenadier is awesome. I really like the fact that is is full-time four-wheel drive (sort of an all-wheel drive), with a locking center diff to get true four-wheel drive. The "all-wheel drive" system provides traction for on-road driving in slippery conditions, when - in a part-time 4-wheel drive - you are wondering if you should shift from 2-hi to 4-hi. For those who drive part-time 4x4s, you know what I mean. I think it will be pretty rare that you need to lock the center diff in the Grenadier on-road.

I almost bought the manual transmission version of the FJ-Cruiser, because it had full-time four-wheel drive, and the ability to shift into true 4-hi (and, of course, 4-lo) - I just couldn't get past the limited visibility in that truck. For a while, the only other vehicle in the U.S. with this system was the Landcruiser 200 (and maybe the G-Wagen).

 

[Arkaig]

 

[bigleonski]

View attachment 7805093

View attachment 7805094

Hmmmm, welcome to the 1970’s.

 

[James]

I was also told by ineos driver that you can lock/unlock centre diff on the move, when i was on a test drive. However, it doesnt make intuitive sense, not because of the transfer case, but because of the torque converter pushing or braking.
on all defenders I can absolutely do this at any speed, providing the vehicle is not turning a corner or wheel spinning at the time, ie the centre diff is not absorbing differential rotations. And you momentarily depress the clutch.
you can not change ratios under way without problems, as stated by others there is no synchromesh. Applies for up or down. Very slow movement I still dislike, better to briefly engage the clutch in the transfer case neutral position, that re-positions the cogs for enmeshment.
im not clear if the grenadier has a defined neutral position for the transfer case, i think not. But, as it has no PTO, and does have an automatic gearbox, there is no real need for it.
I think the cnetre lock on the move is probably a casualty of the automatic gearbox, which, on balance, I feel is probably worth it. 20 years ago definitely not, but these autos are brilliant, and this is not a 20 year old design - happy about that!

 

[Wayneos]

The video doesn't show what he's doing at the 34:24 min mark, and he refers to the CD being open or closed in LO. So I assume he's LOCKING and UNLOCKING the CD on the move.

Then at 34:44 slows to a stop (or almost stop), puts it in N and changes from LO back to HI

View: https://youtu.be/9Wbr_UCfZcs?t=2004

View: https://youtu.be/9Wbr_UCfZcs?list=LL&t=2020

 

[ADVAW8S]

You have to be in neutral to lock the centre diff
It doesn't have synchro

In theory, I could be going 35, switch to neutral, lock the diff, and put it back in drive.