Thanks, that makes sense to me. So driving on the highway in the winter where you don't know the conditions (Could be black ice, slush puddles etc) that first setting (grass, ice) would be the best. Yes it really does not want to spin the wheels at all. It must sense spin then immediatly cut power (or maybe break the wheel) As it almost felt like I was in neutral when i used it.

HDC?

 

I'm not sure if my rear differential locks. I have the HSE and I think there was one option higher that came with a full sized spare tire and locking rear differential. When the transfer case locks what is that doing vs when its not locked?

 

HDC = Hill Descent Control - not something I would leave on during normal street driving. I would certainly use it on the streets as there are times where it is extremely beneficial, but I wouldn't leave it on all the time. For example, my dad lives on top of a mountain. To get down the mountain in the winter, I would use HDC. It's amazingly good, though you have to "trust" the computer and keep your feet off the pedals. As Jafir commented earlier, you can also adjust the speed of your descent via the cruise control +/- buttons.

As far as driving in the winter when there is combined water/ice/slush... yes, I would either leave it in the snow/grass setting or else just in the normal setting. Would just depend on my mood that day.

Concerning the locking rear differential - it was offered as part of the HD package. Yes, you are right... you would get a full size spare tire with it.

Concerning the locking transfer case, I did a little digging (might as well finally educate myself) and it appears as though our transfer case is a differential/muli-plate clutch arrangement. Basically, there is a clutch pack that is mushed together (technical term) so that all the discs are spinning with all the other discs. Thus, 50% power to front axle, 50% power to rear axle. Now, I assume this clutch can be released electronically or can slip with high power application, and thus you can get more power to one axle vs. the other. In situations where you want to maintain the 50/50 power split, the car can actually lock the differential, thus providing the constant input/output.

See here for info on the transfer case:
http://www.rangerovers.net/forum/6-r...-teardown.html
See for info on how a transfer case works.
See for information on a multi-plate clutch arrangement.

 

I don't like HDC engaged in snow and ice. It has caused me to spin out in the past. Low range is low enough and the benefit of torque-arresting is offset (IMO) by the lack of stability.

 

Nice videos!

So in normal mode on dry pavement.

Lets just say it has the guts to spin tires on dry pavement.

If I floor the gas how is the power distributed?

ie. one front and one rear tire gets the power? 50 percent to front left tire and 50 percent to rear right tire? Or something like that?

 

My understanding: The front driver and rear psx tires would spin with torque being split at some pre-determined % distribution; once the tires spin and a certain torque-threshold is reached, the center diff will lock at 50-50 torque and the TC would likely kick in as well if there is still spinning of tires.

 

I honestly don't know the answer to this question because I don't know enough about the differentials... any diff experts want to chime in? If it's a true "open differential", then the traction control would really be controlled solely by the locking transfer case and the ABS system. In other words, if you lost traction on one wheel on each axle, then the opposite wheel on each axle would just spin. Of course, this is where the ABS system jumps in and applies the brakes on the spinning wheel to try and force power to the wheel with traction. If, on the other hand, the diffs are limited slip, then they should be able to apply some percentage of the power to the wheel with traction on each axle, even without the ABS system...

 

Or...

Put a LR3 up on blocks so all 4 tires are off the ground.

Which tires spin? Just one in front and one in back or all 4 at same time?

I actually saw this in real life. One of the guides went over a A shaped peak and he balanced the car in the middle. All 4 tires were off the ground and he was like a teeter Totter.

The trick was to gas it over the peak, he tried to crawl over it and got hung up.

I just put a tow strap on his front end and pulled him free.

Trying to remember but I think just 1 in front 1 i back spun. they did not seem to ABS either as left it in gear idling and the tires were spinning on their own.

 

What I would expect to see happen is that the front driver and rear psx wheels will spin, then TC would kick in, braking the front tire and spinning both to some extent. In the rear, the same thing would happen...but if the vehicle has the HD package both would spin with equal torque.

I could be wrong, but that's what I'd expect.

 

I went off the grid this past weekend, on various types of hills, trails and fields, where the snow was approximately 1 foot deep, and very very powdery. The snow had not melted at all, and the temperature was around 10 degrees F. This resulted in very little grip. There was simply nothing for the tires to bite into. I did air down to about 15 psi, and this did help slightly. I have the HD LR3, so it has the rear locking differential. I experimented with various settings. I found the best setting for getting through the snow, especially uphill, was Sand mode, Low Ratio gearbox, automatic, with the DSC turned off. It was great fun! Needed to use the Winch a few times. Didn't do too much damage - Slid back into a tree and cracked the small red reflector on the rear bumper, and my left front black plastic wheel arch got snagged and a couple of the clips broke, so I took it off.