To use 4wd on dirt roads or not?

Back when I had to get out and lock the hubs I wouldn't bother. Now with all the auto shift on the fly 4wd systems around I prefer to use 4wd. Seems to be safer when you hit a slippery patch.

There can be no doubt that the vehicle is more stable when in 4WD on a dry loose-surface road.
Furthermore, tyre wear is more even in 4WD. On a recent reasonably rapid trip along the Great Central Road I did not use 4WD and found that my rear (driving) tyres wore twice as much as the front tyres.

Just remember to take it out of 4WD when you hit a sealed section! Of course, you can leave the hubs locked until 4WD is next needed.

Yep any dirt road of any quality equals 4WD... that's why we buy them

Nope. Only when actually off road and if needed. I forgot to take it out of 4WD when we hit the bitumen once and had fun at the next town. Also we tend to use more fuel in 4wd.

Phil

Gday,
As you've probably worked out by now, its a personal choice.
Its easier to control your vehicle in 4x4 but you will probably use more fuel and increase diff and tyre wear.......
You need to weigh up whats more important in your case.

Cheers

I put ours into 4wd even on short 3km stretch's of dirt. With our old 4wd (the first one we had ever owned) the manual said to do this to ensure the 4wd mechanism didn't seize up with dirt and grime.

Depends on the dirt road and the condition it is in when your on it.
I have come across some dirt roads that are actually in better condition than the black top.

Allways in 4WD on the dirt.
Improves handling, especially braking.
Halves the loads on the mechanical bits doing the work and spreads the lubricants around.
The difference in fuel consumption in the OKA is not measurable.

When we bought it, OKA196 had done 330,000km and did not have free wheel hubs fitted. I fitted them. I now consider that a mistake. I simply added a weakness and a complexity into the drive train that I did not need.

Cheers,
Peter
OKA196 Motorhome

In my opinion.

Use the system the way it was intended, all loose surfaces use 4WD.

With all the fuss about the environment and fuel consumption you would think that 4WD manufactures would be putting in freewheeling hubs, not taking them out, if they saved that much fuel..... just so the could get a better Co2 reading and consumption readings....

The reality is that, constant or AWD does not increase fuel consumption greatly, nor does it wear out components quicker. If it did there would be an outcry of the vehicle is not able to do what its designed for....

Unused components sitting un oiled with grease packing to the bottom of the bearing attracting condensation and rust is more likely to fail when needed that a well oiled and used component.

What it does do is allows you to slip into and out of 4wd as needed, it also spreads the strain across 4 wheels and 2 axels providing your 4WD with the best of front wheel drive and rear wheel drive at the same time, as well as improved braking as those big disc brakes on the front are now supplementing those drum brakes on the rear of most Utes.

Vehicle control and handling is better, corrugations, washouts, pot holes and those unexpected things that may occur. this is the reason for buying and paying a premium for a 4WD in the first place, seems strange not to utilise it when possible......

In my experience roughly 90% of resource industry mine/environmental/geologist etc. vehicles that do have freewheeling hubs have them locked in.

All those new vehicles without freewheeling hubs can't be wrong.. can they?

I thought it is recommended to use 4WD on dirt roads to lessen the formation of corrugations.

I was a 4wd instructor for ten years and have learn't the full meaning of 4wd.
I have also travelled over nearly all the Iconic Australian roads towing trailors and an off road caravan as well as a standard type caravan doing all this in 4wd when on any gravel or unsealed surface without any problems.
I have always believed that the 4wd gives better stability and braking ability when in use.
As there is in most 4wd vehicles an indication on the dash showing when one is in 4wd or as on some vehicles constant 4wd types that the centre diff has been locked.
A glance at the dash will therefore remind you that you are in 4wd or locked up.
It is usually very simple to disengage by an electronic switch or via the small transmission gear lever when back on a sealed surface.
When disengaging or engaging 4wd you should be driving in a straight line and take the foot of the go pedal whilst doing so.
As for free wheeling hubs they can be disengaged at the next stop.
Remember to read and follow the instructions in your vehicles handbook.

Ok, just my take on the subject.
If you are travelling on a gravel or loose/slippery surface at a speed that feels unsafe maybe consider slowing down.
Two different (maybe three) types of vehicles being discussed.
Part time 4WD, usually fitted with free wheeling hubs and no centre differential. To have the benefit of 4WD you need to shift the transfer case from the 2WD Hi Range position to either 4WD Hi Range or 4WD Low Range and either get out and put the FWH in the locked position or rely on the auto locking hubs to achieve this. Be aware that on a surface that will not allow the tyres to slip a little you will end up with drive line wind up. This will put extra strain on all the components involved and most probably increase your fuel consumption to some degree depending on the surface. Will this increase "driveability", most probably unless you have some type of auto locking differentials in the rear and/or front axles. If this is the case you might find some very exiting steering characteristics (read dangerous).
Full time 4WD, usually not fitted with FWH because without the hubs engaged you will not go anywhere. To me this is the "best of both worlds" type of system. Drive is directed to all wheels but the centre diff prevents transmission wind up with the resulting possible excessive drive line wear or failure. As someone else has already observed, with a system like this, lift one wheel, front or rear, and unless you have some type of auto or manual axle diff lock you go nowhere. To engage positive 4WD there is usually some type of selector mechanism which will lock the centre diff. This system is directing drive to all wheels whether on loose or hard surfaces. Regardless of opinions, my experience is that all this sophistication come with a small loss of fuel economy however allows driving on loose surfaces with a bit more control.

Cheers
Pop

I looked at this thread expecting there to be a lot more argument, what a pleasant surprise.

I agree with what most people have said here.

In the GU especially wiht that super LSD in the rear you have to be a bit careful, it winds up more quickly than I expected. Something I experienced when camped at Innamincka for a week.

My rule, based on experience, if its kicking up dust I use 4wd, no dust no 4wd.

Duncan

I drive a 97 twin cab hilux, 4wd. I don't go 4wding very often so don't have a lot of knowledge on the topic.
I have a couple of questions.
What is the actual reason for having the lockable hubs?.
Can I leave them locked permanently and just flick from 2wd to 4wd from the inside lever when I do decide to go offroad?.
What are the negatives of doing this?.

Thanks all.

I use 4H...even on slippery,wet,icy Victorian roads because in a Pajero I can. A lot safer & I am using the vehicle for what it was made for....just like usingthe gears. Selecting the proper gear to negotiate the hazard.

Well me being new to 4wding I was wondering the same thing on a recent trip. The roads were mainly dirt but for the most part were in very good condition. I was towing out CT and only used 2wd, when we hit some rougher stuff I put it into 4wd.

I was worried about transmission wind up, I had heard about it and know that it can occur when in 4wd on bitumen, but can it happen on dirt?

If I am travelling along a dirt road that is in very good condition at approx 80kph is it safe to use 4wd or do I still risk transmission wind up?

My current car is full time 4WD but when I had a part timer I selected 4WD for gravel roads (99 Jackaroo) - that vehicle mainly did city travel, so the $ I had invested in 4WD hardware might as well earn it's keep on every bush trip - if properly lubricated at services, that front end drive hardware will still hardly be worn compared to everything else, when you sell or trade the car.

without a doubt, even on good gravel like the GCR the vehicle drives a hell of a lot better and safer, in 4wd.
One constant we find is in the case of rollovers, they usually still have the little stick firmly planted in 2H.
Personally, I'd happily cop a bit of extra fuel use any day.

Cheers
Al

My vehicle is a Prado. It's AWD (4WD with a centre diff) until you engage 4H or 4L.

I believe the torque split in AWD is 40% front, 60% rear. With that in mind I don't use 4H unless I forsee a traction issue. It drives and tows beautifully in AWD on dirt and gravel roads.

You can get transmission windup on hard dirt, so I tend not to use 4H until I see a specific need for it.

Cheers

Having spent a bit of time on dirt roads (I live in Alice Springs) I much prefer to stay in 2wd but more importantly adjust tyre pressure. Travelling up the Tanami from Alice to Halls Creek, our fully loaded Prado with 240L of diesl on board, we drove it in 2WD and 28lbs in the rear....

When in more challenging terrain we move to 4wd, even if its debatable its better to stop tearing up the road (digging holes) and just leave a set of tyre tracks :-)

Pete

I have a 4x4 ute with an aluminium tray. It almost always goes into 4H on the gravel, because if I don't the back end bounces around all over the place and skips sideways when you hit a pot hole. In 4H it tracks happily in a straight line.

The other reason is that it has a tendency to lock the rear wheel when heading down a slope and the brakes are applied. By having in in 4H and the rear wheels tied to the front, it is more like a poor mans ABS and the rear doesn't lock anywhere near as easily.

I did drive a Landcruiser troopie over good gravel roads with a bit of a load on and found that after after 100km it was almost impossible to get out of 4H. The hubs were then unlocked and it still wouldn't release. In the end I stuck two wheels in the loose gravel on the side of the road, revved it a bit and dropped the clutch. The wheel spin was enough to remove the tension in the drive line and let it come out of gear.

I could have jacked a wheel up, but spinning gravel was easier.

So from what people here have said, am I right in assuming wind up is common and if H4 is used on decent gravel roads wind up is to be expected?

I am just trying to understand it and am wondering if wind up can cause any long term damage.

As long as there is some slippage which allows any accumulated torque to dissipate, then wind up us unlikely. A heavily laden vehicle on a firm surface with will press onto the road more, reducing the chances of tyre slippage.

If the surface is that firm enough to get that much traction though, then 4H is probably not required in the 1st place anyway.

Keeping the tyres the same diameter and with even wear on all corners will help a lot too.

This is at the extreme end of the scale, but it can happen. This is from a Land Cruiser that had the centre diff engaged and it wouldn't release.


http://www.landcruiserclub.net/forums/showthread.php/42260-Help-Centre-diff-lock-not-releasing-light-going-out

Hi,

Like a lot of others have said, I leave my hubs locked when away on a trip and change between 2 and 4H depending upon the surface of the road. If it is a good dirt surface I'll leave it in 2. If it is sandy, gravelly/rocky, wet or corrugated, or a chance of damaging the road surface, I will change to 4H. I tend to travel at a fairly relaxed pace :)