Driving long distances in H4

In my opinion and if you are not going over 80kmh, then it is sensible to utilise the 4WD ability that you paid for.

Putting traction through to both axles is better than just one.

Some will say fuel cost will rise and other will say wear and tear...

But most newer 4WD's do not have free wheeling hubs, so that theory seems depleted.

As I said, thats my opinion, I am sure that there will plenty of others... :)

On loose gravel you'll have no problems and the car will be more stable. Just make sure you go back to 2wd on the hard stuff. That includes hard, clean dirt surfaces, ie not covered with loose gravel. That's just as bad as tar for transmission windup.

yep that's what it's made for so no long term issues.

"long distances"..... that might be the important part of your question.

If you say drive 100ks of 'dirt road', you may end up travelling for a couple of ks on firm surfaces where diff wind up might be a problem. Generally though at around 80ks you shouldn't have a problem.

I tend to not have the hubs locked mostly because I then forget to unlock them!

It does not matter what speed you are doing, if you are on loose surfaces you should be in 4wd.

Many mine sites require 4wd to be engaged when you come thru the gate, the army and many institutional users of 4wds, require 4wd to be engaged on all "unmade surfaces"

The improvement in stability and steering control is considerable.

Where is makes a huge difference is on well made roads that see a lot of traffic...good roads ,fast roads..... as a result they have a good hard smooth pack but they have a loose top surface with lots of marbles along the edges and on the outsides of the corners.

when you meet another vehicle and have to take the outside line on a corner on such a road you will either wish you were in 4wd or bless the fact that you are.


As far as a dirt surface with sufficient traction to cause transmission wind up...that would be a very rare thing indeed..it would have to be a very hard packed road with a lot or rock in the top course and devoid of all loose material.

as far as any top speed.
the faster you are going the more you need to be in 4wd...there are many competitive 4wds that do well over 100Kph for days at a time in 4wd.

There is no good reason, to not engage 4wd where it is appropriate.

As a matter of safety and comfort...use 4wd in any situation it can give you an advantage......that is what you paid for.

what you should do is find out the habits and requirements of your transfer case and practice the shift from H4 to H2 and back again..........for those irritating short sections of bitumen you will find in the middle of nowhere.

cheers

That's great info.

I asked this question to someone who repairs them, and he looked at me oddly when asked. "Why waste the fuel?", was the reply.

I use H4 when coming out of rough spots on the short dirt stretches and notice the huge improvement in handling on corrugations. I naturally would prefer this handling all the time, but wasn't too sure what 5-600km would be like for the car, in one day.

It seems it'll handle it from the above responses. I may take an extra Jerry of diesel, though...

Joshuah.

Interesting question, and while I have no argument over anything said (except fuel & tyres) I find no motivation to lock my hubs in on unsealed roads. I believe it uses more fuel..my hilux sprayrig uses 20% more with the hubs in while spraying at 15KPH
2nd gear low range, than without & turning circle increases immensely. Avoiding
rocks etc ..eg steering..is much easier & accurate in 2wd. Perhaps that doesnt transfer
to onroad driving, but I cant see why not.
Front wheel drive increases tyre wear..fwd tyres wear out at a higher rate than than
rwd..in my experience anyway. I suspect such wear is increased by driving constantly
with the hubs in.
Does it really matter?..Probably not, but I dont see the perceived safety/handling
advantages being greater than the downside.
Whenever this topic comes up among my considerable number of farming 4wd
driving colleagues, the answer is ..no...burns fuel & stuffs tyres....
but what would a heap of old cockies know anyway?..:)))))).......oldbaz.
your hubs....your choice.

Short answer ........ NO .............
If it an "older" 4wd with free wheeling hubs it drives like crud with them in and uses more fuel and yes i have trialed it long distances out and in and it is far better to drive it with hubs OUT and OUT of 4wd, gearbox will last longer as will diffs and transfer case, it will run cooler in the gearbox and really if you lose traction to the point when it has problems moving forward, then and ONLY then put it in 4wd ....... yep new cars have constant 4wd and are designed for that, old ones aint .... and i know for a fact in the Hilux's and 75 cruisers they are harder to control if the 4wd is in, it tends dart and jump around, more so on loose surface's .........
The MOST critical factor that needs altering according to conditions is tyre pressures ..........
Cheers
Joe

I'm for it. If I have any concerns with wind up, I occassionaly flick it out of H4 and then back in on the run. There hasn't ever been a time when it was stiff to get out, indicating a bit of wind up. As for handling (particularly older stuff with no ABS etc) just try doing an emergency stop in H4 and H2 and compare the difference. I do it for the decreased stopping distance alone.

When I had my Patrol ('02 3.0Di) I would engage 4H as soon as I hit the dirt. Nocticeably more stable, particularly with a load on, less chipping on the rears and no noticeable difference in fuel economy. Never bothered with short causeways and so forth but longer stretches of blacktop I shifted out on the fly. Probably covered 70,000K this way. Sure the T'fer case fluid looked like it was 'used' come change time but that's what it's for eh! Did it with the Jack I had before that. The Cruiser I had was born that way and D4 I have now does it for me + a lot of other stuff.

IMHO if you are not doing it you are leaving grip on the table.

OBT

I completely agree with Tony and Mr. Bitchi. if you note that you have stretches of hard paked stuff, jus ease. the left wheels onto the shoulder avery so often(at suitable speeds of course)

HMMMM !! Its a bit long winded to read all but I have on many occasions, on corrugated and rough dirt roads, run in 4H.. I reckons it smoothes the ride and gives more control to the driver.. The fuel thing is debatable, I think it does not matter that much, if it uses extra fuel, it cant be much extra and when you are away, you expect to use extra fuel if you encounter hard going tracks.. My thoughts only!!! Michael

Righto, but I'll give it a go.

Although the manual states that H4 is for 'wet, icy or snow-covered roads', I'll assume dirt and corrugations fits in that part too.

Good point about the heat of the transfer case and front diff. More regular oil changes would help there. But safety if key, so I'll use it when the going gets loose.

It's been bloody helpful, all these replies. Thanks!

I engage 4x4 on most dirt roads if there's loose or slippery surfaces. (The distance & speed is pretty much irrelivant) Overall using 4x4 gives you greater control, improved braking & on some surfaces minimises the formation corrugations.
Negatives: I wouldn't do it if your tyres wear or size was different.
Fuel consumption on my "old fashioned' manual hub locking HiLux" increased by 1 to 2 MPG. (1/2 a litre per 100) Cheap piece of mind & you certainly wont need another Jerry-can Josh ;-)
Cheers Craig.............

Joshuah,
I have done what you are talking about many times with a difference.

I will lock my hubs in and run high 2wd and if the road I believe is dodgy and I need high 4 I just pull the lever. I don't care what speed I am doing when this occurs as everything is in harmony front and rear drives are travelling at the same revs.

I also agree with Joe and Mel about the handling of an old style part time 4wd like his and mine. They do tend to dart about.

You will use more fuel and you will have more wear.

I know you are talking about a gravel road and not a wheel rolled clay road so you won't suffer from wind up at all.

As for transfer and front axle wear you will get that but in the big picture I would not worry about it. We run locked low range 4wd and some of these vehicles do 100,000k in this manner. They also run on bitumen for around 2k a day with 90 degree turns and all they destroy is CV's which are partly destroyed by much turning and full torque all day.


I find mostly I just stay in 2wd and travel at a speed that suits the road or track.

Have a good one,
RA.

PS. once drove 100k accidentally up a twisting highway with the cross locks engaged on a prime mover and loaded trailer. Didn't tell the boss and that truck went on to clock up well over 1,000,000 k on it's original rear end.

Loads of good advice on here.

Just as an extra.....and if you are interested - Pop onto the Bridgestone Tyres website where there's a really good video demonstating the advantages of 4x4 over 2x4 on gravel roads in the Flinders Ranges.

It's for the D694's but equally applicable to any tyre.

Even on my relatively quiet dirt road I now always switch to 4x4........just in case.

All the best - Wayne