Are you saying that the driver can't decided when to engage the diff locks? If not, on what basis does the computer make the decision to engage them? Wheel spin? If that's the case, what is the advantage of diff locks over the ABS-based traction control? The benefit of the lockers is lost if they cannot be engaged proactively. Yes Yes Yes to all of this. It's an oxymoron to see a vehicle with diff locks and 21 inch rims and skinny sidewalls.

 

@Troyan2019
Are you saying that the Disco 5 diff locks can only be engaged by the computer? If that is the case, what is the basis upon which the computer does so? If it is wheel spin, like the ABS-based traction control, what then is the advantage of diff locks? If they can't be engaged proactively then aren't they just redundant to the traction control?

Everything you said about having the proper tires with plenty of sidewall is spot on. It is almost oxymoronic that a car equipped with diff locks comes with 21 inch wheels and skinny sidewalls.

P.S.: This is my second reply to Troyan. In the first reply I wrote, I included two quotes, which I've come to learn automatically flags the post for moderation, which can take a week. So I rewrote the post with no quotes.

 

My center dif on our disco 5 locks as it sees fit during normal driving. I believe it locks and stays on in several of the offroad modes... i don't have the manual with me and will look in to it.

 

Good to know about the moderation!

Here is a video of a guy with the HD pack on his LR4 and he found the only way to "trick" it was to put it in rock crawl mode which locked Center and rear diffs. My guess is that it functions the same way on the D5.

But there are no actual manual switches called "Center Diff Lock" or "Rear Diff Lock" like you'd find in a 4Runner or G-Wagen or various other traditional 4x4s.


My GUESS is that in the other terrain response modes, the computer will mostly lock up the Center diff first and then only if significant traction is lost, would it look up the rears temporarily. I could not find any technical notes on it and there are probably other folks in the LR4 or this forum who have an HD Disco 5 who can confirm.

I did use Rock Crawl mode in my non-HD (no rear locking diff) LR4 a LOT and I will say it's incredible what it can do, but it's not the same as being able to proactively and manually turn on a diff lock and then drive into the obstacle with low to no momentum which is easier on the driveline.

 

Well, I took the D5 with standard terrain response, stock tires, and center-lock only to an off-road park outside Chicago (The Cliffs) yesterday. It was dry and I opted for the easy course which was mostly rocky with some decently steep little parts. I aired down the tires just a bit (into the upper 30s — I could’ve/should’ve done more), put it in deep ruts mode and low gearing, and went at it. Fun and super easy! The terrain response locked the center diff right away when going up steep hills, some had a little hint of mud, but mostly it was open. With some more experience and better shoes, I could do a lot more — if I’m willing to take the risk with an expensive machine!

 

Just saw the latest SUV Battle video.


The section with the Gwagen gives a good example of performance with different lockers. In this example simply using the lo gear outperformed rear locking diffs.

Unfortunately not much talk is given to the LR since the RR walks up the terrain in auto mode 😆

I hope they add a Discovery to their videos but the RR has also come out tops in their prior tests.