4wd Auto Tips

[Ravamedic Lurker Find all posts View Profile Close Ravamedic]

Hi Guys -

I have recently purchased a new Prado after decades of driving Manual 4WD's im a bit lost with the auto and all the buttons..

With my 120 I would drive it in H4 whenever I left the black top - I love the stability and handling.

With the auto, I believe its always in H4? Is this right? If so do I engage the centre diff lock when off the black top, or only when I get in the shit?

I'm keen to hear what others are doing..

Reece

[mickmac_42 Senior Member Find all posts View Profile Close mickmac_42]

Reece,

You should have a knob on the panel underneath the stereo. It's labelled with H4 (high range) and L4 (low range). You can change between the two by selecting neutral and turning the knob. H4 is for general getting around. I've only had it out of high a couple of times. I only use low range if i need lots of torque, if i'm towing something offroad through a tricky bit, or needed to drive slowly with good throttle control. The engine is strong and the auto transmission is pretty smart. The owners manual and guide to offroad driving should answer most of your questions.

Mike

[Richoson Avid PP Poster! Find all posts View Profile Close Richoson]

Reece

I engage the centre diff lock when on soft sand, and when the going starts to get slippery, it gives a good deal more control. I also use the manual shift when in low range, I subscribe to the theory that putting it in low range when off roading is a lot easier on the car, bearing in mind that this will limit the top speed to around 40kmh.

See ya on the tracks, Richo.

[Ravamedic Lurker Find all posts View Profile Close Ravamedic]

Thanks guys -

I thought I may have had to engage the centre diff locks, just as I would have engaged the hubs on the LC70 or put the 120 into H4.

Had a good day today, took the girl out for the maiden off road voyage. Spoilt for choice here in the NT.. Will add some pics when I work out how.

Reece

[brogers Advanced Member Find all posts View Profile Close brogers]

We have a 150 GXL D4D Prado, and have done quite a bit of offroad driving, Fraser a few times, Bribie, Moreton, Stradbroke, soft sand, dessert, long dirt tracks, and a little bit of mud, and I love the auto. I got talked into getting an auto Prado, and now will never never never go back to a manual.

I have tried all sorts of things as people have suggest them, and afer reading the manual, and the off road guide that came with teh car, but I now truely believe the key to good offroad driving is .....good tyres, appropriate tyre pressure and a suitable suspension lift.

Sure, you can do quite a lot in the standard OEM configuration, and we did a lot of off road with standard tyres and suspension until the tyres and the suspension got worn and now we have replaced both with better off road gear, and wow, what a difference.

We now have BFG A/T tyres, and have a 40mm suspension lift, and its a very different car, the clearance makes such a difference off road, and it is still great to drive on the road as well. It doesn'rt bottom out nearly as much, it clears the sand and dirt much better, the tyres have made a huge difference, and with thise three things correct, (good tyres, appropriate inflation pressures and a suspension lift) even my dear misus can usually just drive the car from the tar to off road without having to adjust any 4wd controls or worry about changing gears or engaging diff locks etc ...just get tyre pressures right and drive the thing...honestly, thats all you need for most common, public access 4wd situations.

We don't tow a heavy load or carry huges loads, and I am sure that makes a big difference. It would be a differnt story i loaded to the maximum I guess. We might have a car load of people and a light trailer with gear, or the car loaded up with light camping gear, but we don't tow a big caravan or heavy camper beyond about 700kg, so we are well below the maximum load and that really helps I m sure.

So....on sandy tracks and the beach, we drop the tyre pressure (depending on how sandy the beach is etc, somewhere betwen 18 and 25psi) and just leave it in auto H4 without the centre difflock engaged, unless it looks really really powdery and a bit steep, eg beach exit points of bigger dunes. Then we might engage the centre diff lock, but thats the exception really.

When Crossing the Simpson, and when we were climbing sand dunes that had been chopped up by people towing trailers or driving with tyres fully inflated, we left it in H4 (so you can have sufficient speed/momentum to go over the dunes) and also engaged the centre diff lock, just so we didn't get stuck near the top of the dunes before the crest, where you loose speed and enter the soft chopped up sand where those towing trailers or with big heavy loads get stuck and spin their tyres in a vain attempt to get over, and in doing so they absolutely chop up the dune track.

In fact, for the majority of the Simpson Crossing we just left it in H4 with the centre diff lock engaged. This is the first time I have just left the centre diff lock engaged for any distance to be honest. Previously I would just engage the centre diff lock if bogged or almost bogged, and then disengage it shortly after when clear of the soft stuff. . Much of the crossing has long straight sandy tracks with regular sandy dunes to climb, and you need some momentum to get over. I don't know what others do, but we didn't get bogged to any extent. A couple of times we had to just reverse back a bit, and have another go, but we didn't need to dig or snatch or winch at any stage. I am sure it would be different if it had rained or if we were towing anything.

In fact, on many occasions, apart from lowering tyre pressures, we just leave the controls as they are for normal road driving. ie H4, no centre diff lock, traction control on, and in full auto, and it goes absolutely fine.

I figure I don't want to use the centre diff lock unnecessarily, as it adds to wear and tear, I believe it worsens fuel economy a little bit and I belive it might make the cornering a little worse (but I don't know this for sure because I don't use it often)....but honestly, I don't usually bother with the centre diff lock, just leave it in H4. Likewise, leave it in auto when driving the firm beach and normal sandy tracks and smaller dunes in most instances. If I am towing the light camper or a the boat, I do use the sports mode, usually S4. In S4 it will still change down gears, it just wont go up into overdrive and it reportedly is better on the auto transmission and lets it run cooler etc.

However, when in thick mud or almost bogged (or actually bogged), thats when you will need lower tyre pressures again, (temporarily go as low as say 12-15psi depending on what load you have on board) , and engage the centre diff lock to maximise your traction, and if getting out of bog and you don't have any momentum and are not likely to get any momentum, also engage L4. Also enagage centre diff lock and L4 if rock crawling very slowly or slowly climbing a rocky slope and you need maximum traction

Everyone has varying opinions about what to do with off road electronic controls. I did a 4wd course about 15 years ago, but some of the electronic gadegtry wasn't common then. Its also very hard to summarise exactly what you do, because each track or situation is a bit different, and we all have different tyres and suspension and different loads etc....but sometimes its just not worth lowering tyre pressures for a short run across some sand, and mostly its just not worth bothering to engage the diff lock and L4...honestly, there are many times where you can just drive the car in usual, public access off road situations in the configuration you use on the highway. H4, and no diff lock, and in full auto.
Love the Prado

[Ravamedic Lurker Find all posts View Profile Close Ravamedic]

Hi Guys -

Thank you for the clarification. I will play around with it over the coming weeks. To be honest, host of the tracks I travel would be suitable for a commodore ute, until you hit the access roads where you need the clearance - I really loved the LC70 and the 120 I owned and I could really feel the difference in handling when I changed from 2WD to H4 on the dirt.

I took her for a spin yesterday without touching any of the control i.e traction control on, in drive and no centre diff lock, and it was really nice to drive, however it may have been my imagination, but it didn't seem to feel as controlled as the Manual in H4 - handling, and control of speed over the slow very rough stuff - I felt I had my foot off the accelerator and riding the brake most of the time. It was perfect on the main dirt highway - a little skiddish around corners - but where I really noticed it was the rough access roads to the water holes - I might in future engage the centre diff lock here and shift down to 2 / 3 - in the manual this track would have me constantly changing from 2/3 and sometimes 1st. Lots to play around with..

I totally agree with the tyre pressures and thought, as a control, I would leave these as set by the dealer, to be honest I haven't checked them and its my first job today, they felt overinflated and will probably leave them between 32/34.

Thanks again. Certainly enjoying being back in a prado, or a 4WD in general, really opens up the possibilities for fun since I live in the 4WD / hunting / camping mecca that is east arhnem land.