Thread: D4 Traction Control System and Indications

Originally Posted by Celtoid

I spent a week on Fraser Island earlier in the year.

Had the 19"ers down to 18PSI to start with but lifted them to 21'ish, as I was concerned about hitting some of the exposed roots at speed. This pressure worked fine in all the conditions.

On the main beach and even some of the soft stuff around the ramps, I just turned the DSC off, stayed in hi-range and didn't bother with any selections on the TC. Every now and again I flicked into Sport Mode to pick the revs up.

When going inland, I selected Sand Mode and low range....it was awesome....

Thats good to hear. How was Indean Head bypass - still slushy and soft and plenty of non-rovers getting bogged?

Cheers

Originally Posted by ozscott

Thats good to hear. How was Indean Head bypass - still slushy and soft and plenty of non-rovers getting bogged?

Cheers

The sand was pretty soft, really deep and chewed up but it hasn't exactly been very dry this year, so whilst you waddled all over the place getting through it, never really felt that I'd go under.

I imagine if it was super, super dry, I need to be a bit less blase about it all.

It was really quiet too.....not many people to get bogged.

Originally Posted by gghaggis

DSC off, sand mode engaged. Use low range (even in sand), unless there is a compelling reason to do otherwise (fuel consumption issues, or need to exceed 60kph continuously). This is more for the wheel articulation (which is increased in low range) than anything else. Remember - the D4 has a 'sand launch' feature that will prevent you digging in when you take off. It works very well. I normally leave it in auto, 16psi.

Rock crawl when stuck.

There's quite a bit more - that's why we run courses on these vehicles

Cheers,

Gordon

Hi Gordon,

How does increased wheel articulation occur in low range? Can that be explained in pretty simple terms?

Cheers,

Kev.

The d3 and 4 with air suspension simulated (to the extent of it's travel at least) live axle by forcing the relevant opposing wheel downwards as I understand it by hyper inflating the bag on that wheel. So eg left front goes up into the guard and right front gets forced down for added traction and stability at the same time which other independently suspended non lr vehicles do not do. Merry Christmas

Originally Posted by ozscott

The d3 and 4 with air suspension simulated (to the extent of it's travel at least) live axle by forcing the relevant opposing wheel downwards as I understand it by hyper inflating the bag on that wheel. So eg left front goes up into the guard and right front gets forced down for added traction and stability at the same time which other independently suspended non lr vehicles do not do. Merry Christmas

Merry Xmas to you and yours too.

But, did that explain the low range bit?.....LOL!!!

Cheers,

Kev.

Originally Posted by Celtoid

Merry Xmas to you and yours too.

But, did that explain the low range bit?.....LOL!!!

Cheers,

Kev.

Sorry Kev, I see what you mean. I know in low range the traction control would be more aggressive but I dont know about the air suspension. Someone else will explain im sure.

Cheers

Hi Kev,

In high range, the cross-axle valve block (CAVB ) is not activated. This is so the car will handle as a fully-independent sprung vehicle. Hence there is minimal wheel travel, but good 0n-road manners.

In low range only, the CAVB is activated and ensures that whenever there is upwards travel on one side of the axle, there is a downward force on the opposite side, hence mimicking a live axle vehicle. So to ensure maximum wheel articulation, and prevent cutting up tracks etc, you should generally select low-range whenever off-road.

Cheers,

Gordon

Originally Posted by Celtoid

Merry Xmas to you and yours too.

But, did that explain the low range bit?.....LOL!!!

Cheers,

Kev.

Originally Posted by gghaggis

Hi Kev,

In high range, the cross-axle valve block (CAVB ) is not activated. This is so the car will handle as a fully-independent sprung vehicle. Hence there is minimal wheel travel, but good 0n-road manners.

In low range only, the CAVB is activated and ensures that whenever there is upwards travel on one side of the axle, there is a downward force on the opposite side, hence mimicking a live axle vehicle. So to ensure maximum wheel articulation, and prevent cutting up tracks etc, you should generally select low-range whenever off-road.

Cheers,

Gordon

Thanks Gordon, that explains it.

Talking about low range....I had a very embarrassing moment a few days ago.

I was up near a mates place, and it has been absolutely hosing down in Brisbane recently, we were having a bit of a drive on some forest tracks...mainly pretty easy driving as it was gravelly with only the occasional bit of slippery mud (which was a bit challenging when traversing sideways up steep sloping tracks).

At the bottom of one hill there was a lot of standing water and mud, as all the run-off was gathering there. I'm still running the OEM 19's so was not going to take any chances. It was not a very big spot of mud but big enough to get well and truely bogged.

Stopped to select low range, turned off the hill descent as I wanted to pick up a bit of speed and then rolled on down. Turned the bend heading for the higher, drier stuff. It was bloody slippery and I felt the truck sliding sideways as well as going under.

Gave the throttle a bit of pressure....engine reved, no increase in forward motion, truck sinks and stops completely. Crap, I couldn't believe I got bogged so easily, even on the OEMs....

Then looked down.......oops....still in neutral..... Engaged drive, D4 pulled straight out of the sludge....LOL!!!

Copped a lot of sledging from my mate though....hahaha.