A few days ago I noticed some odd behavior with the differentials locking and unlocking, and I'm wondering if this is normal or if anyone else has noticed this behavior. While I'm driving, the middle and rear differentials show locked when I stop, and remain locked when I pull off. They will stay locked for several seconds until I reach 20 mph or so. They are not completely in sync during all this, as sometime the middle is locked while the rear is not. And sometimes the rear is locked while the middle is not. I thought perhaps this was due to the car not being warmed up, but the behavior happens even after driving for a while.

I had a full size RR a couple of years ago, and I do not remember the differentials acting this way. BTW, I can only see all this happening on the screen as there is no indication (vibration, clunk, etc) from the drivetrain.

I am also experiencing the non-functioning auto start/stop. I wonder if the differentials being locked are somehow disabling that feature (probably crazy speculation here).

 

Mine does the same thing, I would say it is normal behavior based on watching that screen for many miles each morning.

I am curious about the partial lock, which is what I assume is taking place when the circle is not completely full yet the "lock" symbol is showing locked. I'm sure it's in the manual somewhere, I just haven't looked for it yet.

Rob

 

Mine varies between partial lock and full lock. I have not been able to determine a pattern.

 

I cannot even conceive of what "partial lock" means. Are you sure it's not just in "trying to lock but haven't completed it yet" mode? On Rubicons when you manually engage either locker you get an icon on the dash that blinks and then after a few seconds goes steady when the locker is locked. Ditto when unlocking. It's the computer saying "I understand that you want me to lock the diffs and I'm working on it, but these are 20th-century mechanical devices and they don't always obey with alacrity, so hold on a second and I'll stop blinking when I hear back from the diffs that they're locked." Any chance this "partial lock" feature is really just the transition state?

 

I believe the system allows for varying degrees of lock depending on how the computer reads wheel conditions. From the owner's manual:I can't find any other info in the manual related to how the differentials work.

 

Thanks. I'm going to try to find somebody with an actual technical detail about what's mechanical and what's electronics with the traction control and locking diffs system. In the meantime, this, from FourWheeler magazine's 2021 shootout of new offroaders, where the Defender finished 4th of 4:

While the Defender was the only vehicle in the test with a locking rear differential, selecting when to use it was left up to the vehicle. We had issues of the vehicle jerking violently to one side when the locker engaged in sand washes and also found it to have issues maintaining axle lock during long hill climbs. A simple, user-selectable axle lock button would alleviate all of this.

We also struggled to find a way to shut off, or in any way diminish, the traction and stability control nannies. This meant that sand driving was a chore and sliding the vehicle in any manor was frowned upon.

The Defender went everywhere and did everything, but it wasn't the pleasant and relaxing wheeling we're used to from Land Rover and Range Rover. And for a vehicle wearing the Defender badge, that was a shame.

Bottom Line

In short, the general consensus among the judges is that the 2020 Land Rover Defender would have made for an excellent Discovery replacement. While it's powerful on the highway and immensely capable off-road, our judges found too many points of contention, and in the end the scoring landed the Defender in the number four position.

 

The diffs in a Defender are limited slip. They can be completely open, they can lock at 50/50 each side, and they can be anywhere in between, like 60/40 or 70/30. I'm not quite sure what the manual means by "the amount of lock being applied." That's not really correct terminology as far as I know. A 60/40 split doesn't represent a particular amount of "lock" in my mind. I think the dial icon starts at completely open, then a little bit on the dial means a 90/10 split, a little more means 80/20, until the dial indicates fully locked at 50/50 split.

Here's an article that mentions this. The article states "the Defender's two diffs are capable of acting as both limited-slip and locking-differentials, and they frequently (and more importantly, quickly) lock and unlock while driving."
https://www.motortrend.com/cars/land...atures-review/

Here's a description of limited slips, probably more than you want to know. I believe the diffs in the Defender are the clutch pack types.
https://en.wikipedia.org/wiki/Limited-slip_differential

There's also plenty of YouTube videos demonstrating how they work.

 

Is the Lock and Unlock on the PiviPro Screen or the Virtual Dashboard

My Pivi Pro and someone elses in the UK shows the Diffs working normally - but the dash shows them turning on and off at various times.

LR are working on a patch for that problem and should have it by 15th April

Seems it needs to be applied in person - not over the air.

So the two screens show different things at the same time and the Pivi Makes Sense.

https://www.defender2.net/forum/topic76950-135.html

 

My 4Runner works the same way. It's either completely open, or if I push the button, it's locked. There is no in between, like in the Defender. I get a blinking light as well, after I've pushed the button but before it's locked. There is an electric actuator that pushes a metal sleeve into position within the differential that causes it to lock. This sleeve won't go into position until the splines on the sleeve line up with the splines inside the diff. That's when the light blinks. When the splines line up and the sleeve moves into position, the light stops blinking. In my 4Runner I can hear a distinctive (normal) clunk when this happens. Here's a parts diagram that shows this. The red arrow points to the actuator. The green arrow points to the sleeve I'm talking about. You can see the fork that pushes the sleeve between the two.


This is what the actuator looks like out of the car.

 

Exactly. Jeeps are the same way. Mine has aftermarket Eaton E-lockers, but they work the same as Rubicon's (not sure who builds them for Jeep.) Sometimes they pop immediately in or out of lock, and other times it takes a few seconds till the splines are aligned and the fork can engage the collar.

So it sounds like the Defender doesn't actually have locking rear diff then? Or am I misunderstanding it? An LSD is not a locker. For instance, my 2014 ****** Wheeler Wrangler came with LSD rear diff. I quickly learned that it was insufficient for low-speed rock climbing when I went to a rock park with my friend with a Rubicon. I upgraded immediately after that. The Limited Slip did exactly that -- limited the slip but didn't eliminate it.

And it sounds like the Defender, if Four Wheeler magazine's review is to be believed, hasn't solved the "how to lock the diff's without a locker" problem satisfactorily either, since it won the on-road parts of the shootout handily and lost out on the off-road parts, of all things!