Auto NP in sand question

[Scottyboy]

Hi Guys,

Just a question for you beach drivers.

I haven't taken my "new to me" NP 3.2 auto to the beach yet. I am used to taking my old clanger hilux manual to fraser. Places with soft sand like getting onto the barge at inskip, towing my camper trailer, I am used to sticking to a gear and keeping the revs up to get through the sand. (had to with old betsy gutless wonder hilux)

Now to get through the soft stuff with the auto towing camper - do I use the sports mode semi auto and pick a gear or just stick it in Drive and let rip? Does leaving it in D cuase any problems (like upshifting when you dont want to) or am I over thinking this?

Thanks

[CeeJay]

In my old Challenger auto I never had to lock it in gear, it wouldn't shift up when I didn't want it to in the soft stuff.

[marcthelegend]

Use manual when you want greater control over gear changes etc. However I just leave it in 'D' When on sand, When you need a little more power, just sink the right boot a little and it will automatically change gears, I find the auto transmission always selects the right gear for the conditions.

I use manual on sand for really soft stuff, mainly because a lower gear will deliver more power, which I find can sometimes sink me down when it gets very soft, if I stop in the sand and i will sometimes accelerate in second gear (it will let you do that). This will help stop excessive wheel spin.

First 4x4 I've ever owned is the pajero, and first drive in sand went well for me, just stick in 'D' and 4H (4Hlc or 4Llc for softer stuff) and you should do great, also would be a great idea to experiment while out there, try it in 'D' and manual mode, its a great way to get a feel for the pajero.

Hope this helps

Marc

[MarkJ]

I do the same as per marc for the most part, but nearly always have it in 4HL as it disables/changes the traction control which woud otherwise overheat the brakes in soft sand and can leave you without power when you really need it...

M

[marquis]

Just as you hit the sand:
a) let tyres down on vehicle to 16psi and trailer 14psi
b) select stability control "off" (if you have it)
c) select 4H (unlocked centre four high) + "D" and idle along.

[mrbitchi]

Obviously opinions vary as I use manual shift. Doesn't really matter. As Marquis said, make sure you let your tyres down first.

[Scottyboy]

Thanks guys - just wanted to make sure its fine to just leave it in Drive - yeah best to play around with it when I get there.... just didnt want to be stuck before I even get on the barge with the wife and kids giving me curry haha.. its going to be an absolute dream compared to the old banga hilux!!!

[geoffma]

Just as you hit the sand:
a) let tyres down on vehicle to 16psi and trailer 14psi
b) select traction control "off" (if you have it)
c) select 4H (unlocked centre four high) + "D" and idle along.

Ive often wondered about 4H in sand. Isnt that worse the 2 wd.
In 2wd, you only get wheel spin if one of the rear wheels looses traction.
But in 4H, you get wheel spin if any one of the 4 wheels looses traction.

Am I missing something, but isnt wheel spin more likely in 4H ?

[mrbitchi]

Yes you're missing something ;-))

In 4H you may get wheel spin on ONE AXLE if one wheel loses traction. However the other axle is still driving and will continue to move you along, negating the wheel spin. That's the whole idea of 4WD :-))

This is assuming that there is some sort of drive proportioning system is place, not an open centre diff. If it is an open system then selecting 4HLC will provide positive drive to both ends.

[nj swb]

Ive often wondered about 4H in sand. Isnt that worse the 2 wd.
In 2wd, you only get wheel spin if one of the rear wheels looses traction.
But in 4H, you get wheel spin if any one of the 4 wheels looses traction.

Am I missing something, but isnt wheel spin more likely in 4H ?

Wheel spin isn't the issue - it's drive. In sand, even a spinning wheel can provide a (very) little bit of drive. It's better to have a front wheel spinning (and providing a little bit of drive) than being pushed and sapping drive. In 4H the front wheels are helping - in 2H they're dragging.

You're missing an important aspect of how an open diff works, and that is that it distributes drive to both wheels based on the lowest traction available to either wheel.

If one wheel is in the air, it has no traction, so neither wheel has drive.

If one wheel has a little bit of traction, the other wheel (which may have heaps of traction) receives the same amount of drive.

On sand, wheels are typically all on the ground, and will all have a small amount of traction (as a minimum) - unfortunately, that small amount of traction may not be enough to provide enough drive to keep the vehicle moving.

If you're in 2wd, and one rear wheel has only a small amount of traction, the other rear wheel can only provide a similar amount of drive (we're talking open diffs - an LSD only complicates this bit ) So you're attempting to move with (2x very little) drive.

If you're in 4H in the same place, both front wheels can receive the same amount of drive as the rear wheels - so you now have (4x very little) drive, or double the amount of drive. (Of course, worst case, 4x nothing = nothing.)

Mitsu LSDs also work very well, so the diff input shaft sees more traction than would be available with an open diff. So, if a rear wheel is the one which can provide very little drive, the other wheels can provide (very little + a little more). So the vehicle has (4 x very little + 3 x a little more) drive.

Confused? Then my work is done.

Bottom line, you bought a 4wd, so use 4wd.

FWIW, on Fraser I found 4H made easier driving than 4HLc, because it was easier to steer out of ruts. In 4HLc the vehicle really wanted to follow ruts.

[geoffma]

I think I'm on the same page. 4H has a proportioned drive ratio of some sort is the key I guess.

Now, 4H on sand, what difference does switching on/off traction control ?

[mrbitchi]

I think I'm on the same page. 4H has a proportioned drive ratio of some sort is the key I guess.

Now, 4H on sand, what difference does switching on/off traction control ?

Traction control can work overtime in soft sand, trying to stop wheel slip. Eventually all forward momentum can be lost. Better to turn it off in the soft stuff. Doesn't matter on hard stuff.

[likatiger]

Scottyboy,

Everyone has an opinion, I am no different. On my second auto Pajero now, the current being a 3.2 DiD, been to Fraser twice, Stockton many times and the Simpson.
Believe me, auto pajeros love sand, I always just leave it in "D" and change from 4H to 4HL (or lower if req'd). In the soft sand, as mentioned, the Stab/Control can be a pain so turn it off AND tyre pressures are the real key.

Enjoy

[Ranger J]

Traction control can work overtime in soft sand, trying to stop wheel slip. Eventually all forward momentum can be lost. Better to turn it off in the soft stuff. Doesn't matter on hard stuff.

Just note that you can't turn off the TC, but can disable the ESC. After a bit of experimenting in the sand myself recently, the ESC just goes wild, braking left right and centre with the change in wheel speeds. Disabling ESC reduces the sensitivity of the TC, allowing a bit more slip (i.e. wheel in air or severe drop in momentum and increased wheelspin - beginning to bog) before it kicks in. Works ALOT better than I had anticipated, especially with tyre pressures down.