OK, I have never owned a 4wd vehicle till now.

During the last rainy season I used H4 on muddy and water logged dirt tracks and it got me out of some tricky spots.

These same dirt roads are now fully dried and caked hard and normal H2 gets me to where I want to go.

My question is; will I do any damage to the mechanisms if I engage 4WD on dry and hard dirt tracks?

Yes, I have read the manual but it isn't really clear. It says to use H4 for off-road.

Thanks for advice.

I only use my 4 wheel drive when it is wet and slippery off road.

The Vigo has no centre diff, so for safety only use 4WD in wet conditions to prevent wind-up and transmission damage.

On loose surfaces 4WD will give a bit extra confidence but switch back to 2WD when the surface firms up.

The Vigo has no centre diff, so for safety only use 4WD in wet conditions to prevent wind-up and transmission damage.

On loose surfaces 4WD will give a bit extra confidence but switch back to 2WD when the surface firms up.

Thanks, so is it OK to use H4 when it rains on normal tarred roads?

The owner's manual also says H4 can be used when on steep inclines and descents. What are your views with this one?

I found a Toyota PDF document here which might be of interest to some: http://goo.gl/1uoXwh

H4 is a very low gear ratio, really for slow maneuvering over very tough terrain. The handbook states you can engage/disengage H2 4WD at any speed below 80KM/PH, L4 when stationary.

The HB also states 4WD must be engaged at least once a month to lubricate it's internals, I do this on a straight piece of road so no stress issues.

H4 is a very low gear ratio, really for slow maneuvering over very tough terrain. The handbook states you can engage/disengage H2 4WD at any speed below 80KM/PH, H4 when stationary.

The HB also states 4WD must be engaged at least once a month to lubricate it's internals, I do this on a straight piece of road so no stress issues.

Sorry, thats wrong. H4 is the same ratio as H2 which can be switched between on the fly at up to 80kph.

Shifting into L4 is the low ratio one which must be done from stationary and is only for off roading.

As others have mentioned, H4 give a more positive drive ion tarmac in very wet conditions, otherwise your best sticking in H2.

H4 is a very low gear ratio, really for slow maneuvering over very tough terrain. The handbook states you can engage/disengage H2 4WD at any speed below 80KM/PH, H4 when stationary.

The HB also states 4WD must be engaged at least once a month to lubricate it's internals, I do this on a straight piece of road so no stress issues.

Sorry, thats wrong. H4 is the same ratio as H2 which can be switched between on the fly at up to 80kph.

Shifting into L4 is the low ratio one which must be done from stationary and is only for off roading.

As others have mentioned, H4 give a more positive drive ion tarmac in very wet conditions, otherwise your best sticking in H2.

Your right, I meant L4.......... H4 has the same gear ratio as H2.

I understand the above posts. What remains now is the periodic requirement (once a month?) to go into H4 to lubricate the drive trains.

Can this be done on a typical dry dirt track which is say, fairly even without loose sand or pebbles?

I am fully aware of the potential damage one can inflict if using H4 on tarmac.

I pondered the one month thing too and agree with Transam. Short time on straight Road so that all the wheels rotating at the same speed should be fine. Don't do it on the twistys.

I understand the above posts. What remains now is the periodic requirement (once a month?) to go into H4 to lubricate the drive trains.

Can this be done on a typical dry dirt track which is say, fairly even without loose sand or pebbles?

I am fully aware of the potential damage one can inflict if using H4 on tarmac.

Yep. The HBook says once a month for 10KM , but as we know in some areas it is dry every month. Soooooo I pick a straight bit of road and do it quite often. I had probs with disengage cos I didn't follow their instructions. Now all OK.

I only use H4 when its necessarry for traction. I would not recommend to use it in "normal" wet conditions (just driving normally in the rain). Though not used much, having a 4wd has saved my bacon on several occasions. I've also had the occasion to use it on very steep climbs before, where I would not have made it without a "run-up" in a 2wd car - though again, as long as you're not slipping in 2wd, I would just use that. Just me personally, but I don't think I would drive on a dry hard track in 4wd as a matter of course - unless it was rocky or gravely or something and I was sliding around.

If you have no opportunities to engage 4wd in your normal course of driving, make sure you engage it occasionally on a straight, slow speed stretch of road. This should keep everything lubricated and working smoothly. I usually engage H4 on the slow drive out of our moo ban on a straight stretch of about 200m. Just make sure you're not doing turns in 4wd on a non-slippery surface.

This is an extract from the owner's manual (page 168):

H4 (high speed position, four-wheel drive)

Use this for driving only on tracks that permit the tires slide, like off-road,icy or snow-covered roads. This position provides greater traction than two-wheel drive.

L4(low speed position, four-wheel drive)

Use this for maximum power and traction. Use "L4" for climbing or descending steep hills, off-road driving, hard pulling in sand, mud or deep snow.

In the case of H4, it says to use where 'tracks that permit tire slide'. I take this to mean if the dirt track has loose sand or pebbles that can result in one or more tire losing traction then H4 should be used. However, if the dirt track is dry and hard without loose sand/pebbles, as is often the case with frequently used access tracks interconnecting farms, then H4 shouldn't be used. So 'off-road' by itself isn't a reason to engage H4 as I see it.

And then for L4, once again 'off-road' is mentioned. As for climbing and descending steep hills presumably on tarred surfaces, wouldn't this be detrimental to the drive train?

Note there is no mention of wet roads either from rain or flooded roads so I guess it is better to stick with 2-wheel drive.

I have adopted what many others have suggested for the monthly lube of the front drive train i.e to do 16km/10miles on a straight tarred road in H4.

Is the ratio between the front and back wheels 1:1 when in 4WD with the Toyota? (I would imagine it is) I remember that when we ran the 4WD tractors, the front wheels would turn 4% faster than the rear wheels to actually make them work for a living. Wouldn't take long to scrub the tyres off if you forgot to take her out of 4WD on the roads.