How D4 Suspension handling on corrugation and Simpson?

[DIS4]

I had always dreaming to have my D4 on Simpson or Cape York one day, but many of those Toyo Fans keep telling me that air suspension will not able to handling the long corrugation. I learnt more each day about my D4, also realized how little I understand what my D4's capability. So often, I know that D4 is capable to bring where ever I want to go if I have enough knowledge about it and prepare to do minor repair if it fails. However, I still encounter many suspension issues so far, many reset by restart the engine and but need to know how to diagnosis it. Just came back from Fraser Island recently, another early D4 had error message of " can not raise suspension due to high temperature" after it sudden drop 0.5m on undetected river creek. would it shock the sensor in this way? We couldn't reset it after tried to pull out the fuse, it once drop to access height and but corrected by pulling out fuse. Even though, the off road height can not be selected due to error message. Will a diagnostic tools solve the issue?

I will not fully committed to a long trip without equip myself with necessary knowledge and tools. Any knowledge and feedback on your experience are much appreciated? Once I thought to have second trucks to do the hardcore offroads and handling the corrugation, but just don't want second cars to sitting outside the garage since miss refuse to drive my D4.

Cheers,

Gary

[Disco-tastic]

Gday Gary.

I havent done those sorts of trips yet, but many on here have. Most of them take a diagnostic tool (Nanocom or Gap IID tool seem popular) which can read and clear fault codes. It can also raise and lower the suspension, which can be handy if your car limits itself to "normal" height, but wont help if it decides to sit on the bump stops.

One handy trick is a "hard reset". Once the car is "asleep" (the park brake light goes out) Disconnect the battery terminals as per the manual, and grab a screwdriver or spanner and connect the positive and negative wires together. DO NOT SHORT THE BATTERY TERMINALS. Just the wires. This removes any residual current from the computers, essentially resetting them.

Put it all back together and start it up. Hopefully the problem will have disappeared! If not, you may have a persistent issue.

I have seen the hard reset work on a D4 that had a height sensor issue after a water crossing, which caused the car to drop to the bump stops on rough ground, stopping all movement. It took about 5mins for the compressor to pump the car back up but it was fine for the reat of the day!

Hope that helps :)

Dan

[Redback]

I had always dreaming to have my D4 on Simpson or Cape York one day, but many of those Toyo Fans keep telling me that air suspension will not able to handling the long corrugation. I learnt more each day about my D4, also realized how little I understand what my D4's capability. So often, I know that D4 is capable to bring where ever I want to go if I have enough knowledge about it and prepare to do minor repair if it fails. However, I still encounter many suspension issues so far, many reset by restart the engine and but need to know how to diagnosis it. Just came back from Fraser Island recently, another early D4 had error message of " can not raise suspension due to high temperature" after it sudden drop 0.5m on undetected river creek. would it shock the sensor in this way? We couldn't reset it after tried to pull out the fuse, it once drop to access height and but corrected by pulling out fuse. Even though, the off road height can not be selected due to error message. Will a diagnostic tools solve the issue?

I will not fully committed to a long trip without equip myself with necessary knowledge and tools. Any knowledge and feedback on your experience are much appreciated? Once I thought to have second trucks to do the hardcore offroads and handling the corrugation, but just don't want second cars to sitting outside the garage since miss refuse to drive my D4.

Cheers,

Gary

Yep those toyota blokes are the experts after all, if someone that has never owned a vehicle, makes a comment on that vehicle, then I tend to ignore that person.

Never had an issue with corrigations, never heard of that error message either, I've crossed 100 creeks, from axle height to bonnet height, never had an issue, I did have a height sensor go and it put up a suspension fault, it had exposed wires, so I'd assume it had contact with something, but it never stopped the car, just press the OK button and continue, reset the car once you stop next, not a problem really, plug in your diagnostic thingy to find the fault code, it will tell you what sensor is the problem, get it replaced when you get the opportunity, for us it was when we got home a couple of weeks later.

A diagnostic tool won't fix the issue, but it will give you an idea of whether it's a serious issue or not, either way you can clear the fault to get you mobile again, a serious problem will put up a different light colour, minor issue is yellow, serious issue red, red means get it looked at ASAP, there's not many faults that will stop you dead, especially if you have a diagnostic tool with you, 9 times out of 10 most issues are minor, that 1 out of 10 will mean get to a mechanic ASAP and that's where the Diagnostic tool will help, keep in mind LRs are not the only vehicle that has that 1 out of 10 moment, they are a pretty tough 4WD, so don't worry too much about the vehicle failing, remember the glass is half full:D

Baz.

[~Rich~]

Yeah done plenty of k's with corrugations, a D3/4 is a godsend in those conditions. Other makes are feeling the pain while you are comfy!
Done the Simpson and a really tough diversion to the Geographical Centre. The early D3 was awesome, the women on the trip always wanted a ride in the Disco! ;)

[BobD]

You can't get a better car for corrugations, other than perhaps a Range Rover Vogue. Corrugations are never an issue for the D4. As Rich said, you travel in comfort while your friends in their 200 Series Toyos or Patrols suffer and complain about them.


Water crossings may be a bit different as there are things that can get wet that shouldn't get wet. However, if you are careful and respect that there are electronics under the bonnet that need to be kept dry there is no problem. I have had water up to bonnet high on several crossings without an issue. Everything under the hood stayed dry due to the seals that provide an air pocket under the hood for a reasonable time.

[kelvo]

Remember on corrugations never be the lead car if Toyotas are traveling with you.

You'll be forever having to stop to let them catch-up.

[IvanR]

Having done lots of outback trips (Simpson x2, A.b. Hwy, Talawanna, and Madigan line last year, in our D3 Have not had a problem with air suspension.
Actually there is one problem and that is because of the good ride you tend to travel too fast which becomes an issue when you suddenly come across a hidden washout or dip. The suspension on occasions can become confused such as suddenly dropping into a hole, but this usually resolved by lifting and lowering the suspension a couple of times. This can also happen after the car has been on the hoist at the garage. One thing that may cause concern is in the morning when it looks like the suspension has dropped overnight. . Travelling slowly over rough sand.hills the air heats up and expands, then the air in the airbags contracts with the drop in temp on a cold night and lowers the car.

Ivan

[BobD]

because of the good ride you tend to travel too fast which becomes an issue when you suddenly come across a hidden washout or dip.
Ivan


That is very true Ivan. Also, the one thing that the air sprung Discos don't like in my experience is small sharp dips across the road. The front suspension bottoms with a big crash whereas live axle cars barely feel it. Travelling with my son in his D1 we often have discussions on the radio about that big hit that I had which he didn't even feel!

[Graeme]

One handy trick is a "hard reset". Once the car is "asleep" (the park brake light goes out) Disconnect the battery terminals as per the manual, and grab a screwdriver or spanner and connect the positive and negative wires together. DO NOT SHORT THE BATTERY TERMINALS. Just the wires. This removes any residual current from the computers, essentially resetting them.

Put it all back together and start it up. Hopefully the problem will have disappeared! If not, you may have a persistent issue.

I have seen the hard reset work on a D4 that had a height sensor issue after a water crossing, which caused the car to drop to the bump stops on rough ground, stopping all movement. It took about 5mins for the compressor to pump the car back up but it was fine for the reat of the day!Simply disconnecting the battery for a second or 2 will cause all ecus to restart their logic. Joining cables together only takes extra time and invites short circuits if a dual battery system is fitted that maintains battery connections after engine stop.

[Redback]

Having done lots of outback trips (Simpson x2, A.b. Hwy, Talawanna, and Madigan line last year, in our D3 Have not had a problem with air suspension.
Actually there is one problem and that is because of the good ride you tend to travel too fast which becomes an issue when you suddenly come across a hidden washout or dip. The suspension on occasions can become confused such as suddenly dropping into a hole, but this usually resolved by lifting and lowering the suspension a couple of times. This can also happen after the car has been on the hoist at the garage. One thing that may cause concern is in the morning when it looks like the suspension has dropped overnight. . Travelling slowly over rough sand.hills the air heats up and expands, then the air in the airbags contracts with the drop in temp on a cold night and lowers the car.

Ivan

Gotta show this to the missus:cool:

[~Rich~]

Oh, and drive using LLAMS set at +30mm is a must!

[LandyAndy]

Ivan make a very good point.
An airbag that is inflated to a height in extremely hot conditions will loose some of the air content overnite due to it cooling out.Same goes for air stored in the airtank.
Has anybody ever considered fitting a second airtank to the system????
Andrew

[Grentarc]

Ivan make a very good point.
An airbag that is inflated to a height in extremely hot conditions will loose some of the air content overnite due to it cooling out.Same goes for air stored in the airtank.
Has anybody ever considered fitting a second airtank to the system????
Andrew
The EAS would fault with a "Normal Height Only" message and fault code for "reservoir filling too slowly" if there was a 2nd tank fitted.

[scarry]

Same as others,done heaps of k's on corrugations,Simpson across and back,Flinders ranges,etc.
In fact the corrugations on the road around Finke and Mt Dare,were, at the time the worst i have ever driven on.
On the roads around the farm in SW Queensland,also no worries at all.

As others have said,the big issue is the vehicle is so comfortable it is VERY easy to drive too fast,which flogs the suspension and will badly chip the rear tyres,no matter what brand are fitted.

A good set of LT rated tyres are also very important,heaps of threads on here about tyres.

[LandyAndy]

The EAS would fault with a "Normal Height Only" message and fault code for "reservoir filling too slowly" if there was a 2nd tank fitted.

Why???
Once they are full they are full,you have the extra capacity,doesnt mean you are using twice as much.
Andrew

[Grentarc]

Why???
Once they are full they are full,you have the extra capacity,doesnt mean you are using twice as much.
Andrew
You have to fill them in the first place. This is when it will cause the fault, and any time you raise the suspension from access to off road, as it will use more reservoir air than normal (stock reservoir doesn't have enough air to go from access to off road all by itself - but reservoir air is used before compressor starts helping), meaning the compressor will have to replenish more air than it is expecting.

[Litlbee]

I had the same problem on a visit to Fraser Island. On my return it continued and found the compressor wanting. I replaced the compressor and have never had a problem since. I agree with a lot of the other comments about corrugations. A D4/3 is the best vehicle to drive on them. To u oat drivers are just jealous. They have to spend big money to upgrade to try and achieve something similar to the ride in a Landy.

[Ferret]

... meaning the compressor will have to replenish more air than it is expecting.

With respect to the "Normal Height Only" message and fault code for "reservoir filling too slowly"

Are you saying that fault is raised only by the compressor running longer than a fixed time period regardless of what the tank pressure starts off at. That is, is the logic - if I run for X seconds and I have not yet reached y Kpa set point then I'm slow - so raise an alarm.

Or, is the alarm raised by a little more complex logic, such as - I'm at x Kpa now. I need to get to y Kpa (pressure set point) therefore I need to run for Y seconds to achieve this. If I run for more than Y seconds and I'm not yet at pressure set point then I'm slow - so raise an alarm.

The 2 logic cases are slightly different.

I get that error occasionally but only when driving away in the mornings after my system has de-pressurised over night a/c I have small but intermittent leak in my emergency air up gear. I have never been able to induce the alarm by cycling the suspension a few times from access to off road height via the buttons in the cab

I am trying to work out if the alarm means I have a problem with my compressor or the alarm would always arise when pressurising from an empty tank regardless of the condition of the compressor.

[rocket rod]

Another area people overlook is the 4x4 info screen. If you have various errors like suspension problems they often show up on that screen and point to the wheel concerned. May save a lot of time diagnosing things if you haven't got a scan tool.

[Graeme]

With respect to the "Normal Height Only" message and fault code for "reservoir filling too slowly"...
I get that error occasionally but only when driving away in the mornings after my system has de-pressurised over night a/c I have small but intermittent leak in my emergency air up gear. I have never been able to induce the alarm by cycling the suspension a few times from access to off road height via the buttons in the cab
The reservoir is held at higher pressure than that required to raise to off-road height and is only filled after height changes have been accomplished, which is why the fault occurs after a few minutes rather than straight away. Cycling through height changes can result in the compressor overheating causing the cooling message but not considered to be a fault.

[Grentarc]

With respect to the "Normal Height Only" message and fault code for "reservoir filling too slowly"...


From what I have seen, it is the rate of rise (or lack there of) in pressure in the reservoir that triggers the fault - xKPA/sec is the minimum rate of rise. When my compressor went, I used my IID Tool to watch the pressures and could almost pick when it would trip the fault due to when the pressure rising rate would slow down.

These compressors are quite low flow rate but high pressure - from memory about 3 CFM @ 18bar, so not much wiggle room in terms of flow.

[IgorKaz]

Yep those toyota blokes are the experts after all, if someone that has never owned a vehicle, makes a comment on that vehicle, then I tend to ignore that person.

Never had an issue with corrigations, never heard of that error message either, I've crossed 100 creeks, from axle height to bonnet height, never had an issue, I did have a height sensor go and it put up a suspension fault, it had exposed wires, so I'd assume it had contact with something, but it never stopped the car, just press the OK button and continue, reset the car once you stop next, not a problem really, plug in your diagnostic thingy to find the fault code, it will tell you what sensor is the problem, get it replaced when you get the opportunity, for us it was when we got home a couple of weeks later.

A diagnostic tool won't fix the issue, but it will give you an idea of whether it's a serious issue or not, either way you can clear the fault to get you mobile again, a serious problem will put up a different light colour, minor issue is yellow, serious issue red, red means get it looked at ASAP, there's not many faults that will stop you dead, especially if you have a diagnostic tool with you, 9 times out of 10 most issues are minor, that 1 out of 10 will mean get to a mechanic ASAP and that's where the Diagnostic tool will help, keep in mind LRs are not the only vehicle that has that 1 out of 10 moment, they are a pretty tough 4WD, so don't worry too much about the vehicle failing, remember the glass is half full:D

Baz.

I'm new to this forum. Looking at buying a Discovery. Currently, I'm a Toyota guy. I have a 76 Series Landcruiser 2013 with all the things you can possibly install/attach to it. BP-51 suspension, underbody water tanks, larger fuel tank and massive list goes on. The stories I was told about the Simpson when I mentioned on Toyota forum that I was going there solo... scared me quite honestly. When I got there, going over every dune I thought this is it, it is going to be horrendous over the other side. It wasn't. This was all the way until Big Red. Unticlimactic really. It's nowhere near as bad as people say it is. Remote, sure. Other than that, there was a fellow I passed who was doing it solo in a Freelander 2. That should tell you all you need to know. Oh and the corrugations... regardless of how good ARB says their suspension is, it was a nightmare for the Landcruiser. I thought the panels were going to come loose and this is with their top of the line Suspension. There are massive bogholes that all have an alternate route right next to them so if you don't tempt fate, you will be fine.

[Redback]

I'm new to this forum. Looking at buying a Discovery. Currently, I'm a Toyota guy. I have a 76 Series Landcruiser 2013 with all the things you can possibly install/attach to it. BP-51 suspension, underbody water tanks, larger fuel tank and massive list goes on. The stories I was told about the Simpson when I mentioned on Toyota forum that I was going there solo... scared me quite honestly. When I got there, going over every dune I thought this is it, it is going to be horrendous over the other side. It wasn't. This was all the way until Big Red. Unticlimactic really. It's nowhere near as bad as people say it is. Remote, sure. Other than that, there was a fellow I passed who was doing it solo in a Freelander 2. That should tell you all you need to know. Oh and the corrugations... regardless of how good ARB says their suspension is, it was a nightmare for the Landcruiser. I thought the panels were going to come loose and this is with their top of the line Suspension. There are massive bogholes that all have an alternate route right next to them so if you don't tempt fate, you will be fine.

Yeah I got those stories too, we did it solo also, in our old Discovery 2 towing a camper going east/west, there will always be some who think these trips like the Simpson and the Cape are tough trips, but in reality they are quite easy if you're sensible.
Nothing wrong with being a Toyota guy, I have a few good friends with Toyotas, two of which have 79 series single cabs, great vehicle, I would have no problem owning a Toyota, in fact I've had 3 myself, but I do take offence to owners of other makes who think they know how good or bad what others are driving and have that "you need a Toyota if you want to do remote travel" gives me the irrits.

We do most of our trips solo, never had any issues that stopped us yet.

Anyway to get an idea of how good the D4 is on corragations, you need to be in the drivers seat, it's far better than our old Disco 2, some sections of our Cape and Simpson trip in the D2 the dash was a blur and I thought the car was going to self destruct:D but we survived, despite all the neh sayers and we didn't need to fix or retighten anything at any stage:banana:

Welcome to the forum by the way:)

[BobD]

We were at Birdsville last year and had a play on Big Red. My D4 was the only car while we were there to get up the hard track on the west side of Big Red and it did it effortlessly. We went for a 30 minute drive into the desert and back to have a look and couldn't believe how easy it was to get up the sand hills. We just drove a steady pretty slow speed and no wheel spin or anything, despite big holes that others had dug with their spinning wheels.


We had our tyres on 18 psi, which seems to be rare, given the guy in a Patrol ute that we helped to get up the west side of Little Red, who, after spending ages letting his tyres down because he couldn't get anywhere, still had 50 psi in them. I put my Stauns on and let them right down and he just drove straight up from a standing start. Before that he wouldn't get more than a third of the way with a run up.


The red sand in the desert is a lot firmer than the sand we are used to in the west, so it is not really difficult at all. The only thing that makes it harder is the idiots that dig up the track.

[IgorKaz]

We had our tyres on 18 psi, which seems to be rare, given the guy in a Patrol ute that we helped to get up the west side of Little Red, who, after spending ages letting his tyres down because he couldn't get anywhere, still had 50 psi in them. I put my Stauns on and let them right down and he just drove straight up from a standing start. Before that he wouldn't get more than a third of the way with a run up.

The red sand in the desert is a lot firmer than the sand we are used to in the west, so it is not really difficult at all. The only thing that makes it harder is the idiots that dig up the track.

That's exactly what I had to do.... drop the pressures (obviously) and take a run up. Being manual, I would run out of steam at the top and just wouldn't have enough to get over from stand still. So run up was a must for me.
Part of the reason I am looking to get into a Discovery. Don't want to drive stick anymore. Getting lazy.
If you went from the Big Red into the Simpson, that's East to West. This is supposed to be the harder direction with steeper dunes etc. what you drove over at the entry pretty much continues all the way. In fact it is probably "steeper" and "more difficult" closer to big red.

[Chops]

I wonder if the guy you spotted in the Freelander was the guy from here. Can't remember his name off the top of my head, something starting with V----
He wrote an extremely funny report about it all.

[LRD414]

I wonder if the guy you spotted in the Freelander was the guy from here. Can't remember his name off the top of my head, something starting with V----
He wrote an extremely funny report about it all.
I had also seen the FL2 story ages ago and went looking for the thread.
Second page, post #12, username Vesko
https://www.aulro.com/afvb/freelander-2/61318-freelander-2-crosses-simpson-2.html

Cheers,
Scott

https://www.aulro.com/afvb/images/imported/2017/01/337.jpg

[Chops]

Yep, that's him, it's a great adventure he had, and he tells it so well too :D

[Disco-tastic]

Thanks for finding that Scott.

I think your AULRO membership title should be "The Archivist" as you always seem to be able to find posts from years ago!

[Grentarc]

Just a note on D4 suspension vs (generic dirt road) corrugations - worn LCA bushes vs new bushes:
With worn bushes, the ride was shocking, shaking everything apart and noisey as hell.
With new bushes (I had to do both front and back bushes on front LCAs) I don't even notice the same corrugations anymore.
This goes to show the importance of checking components like these bushes before a decent trip

[PAT303]

I'm new to this forum. Looking at buying a Discovery. Currently, I'm a Toyota guy. I have a 76 Series Landcruiser 2013 with all the things you can possibly install/attach to it. BP-51 suspension, underbody water tanks, larger fuel tank and massive list goes on. The stories I was told about the Simpson when I mentioned on Toyota forum that I was going there solo... scared me quite honestly. When I got there, going over every dune I thought this is it, it is going to be horrendous over the other side. It wasn't. This was all the way until Big Red. Unticlimactic really. It's nowhere near as bad as people say it is. Remote, sure. Other than that, there was a fellow I passed who was doing it solo in a Freelander 2. That should tell you all you need to know. Oh and the corrugations... regardless of how good ARB says their suspension is, it was a nightmare for the Landcruiser. I thought the panels were going to come loose and this is with their top of the line Suspension. There are massive bogholes that all have an alternate route right next to them so if you don't tempt fate, you will be fine.

I know where your coming from mate,I've driven solo across vast parts of remote Oz in Land Rovers only for non Land Rover owners to tell me I won't make it.Lucky for me I have poor hearing.:D.

[PAT303]

That's exactly what I had to do.... drop the pressures (obviously) and take a run up. Being manual, I would run out of steam at the top and just wouldn't have enough to get over from stand still. So run up was a must for me.
Part of the reason I am looking to get into a Discovery. Don't want to drive stick anymore. Getting lazy.
If you went from the Big Red into the Simpson, that's East to West. This is supposed to be the harder direction with steeper dunes etc. what you drove over at the entry pretty much continues all the way. In fact it is probably "steeper" and "more difficult" closer to big red.

I went west to east and twice had Tracey get out because I didn't want her I the vehicle if it went over :o.We went in November and there was no track,there had been very strong winds with high temps so we had nothing but sand hills,at one point we simply drove towards the morning sun.After the fourth day way off across a clay pan we saw a reflection,20 mins later you wouldn't believe it but a green Td5 defender turned up,they were lost also and navigated by keeping the morning sun on their backs:cool:.After that we were all good,they followed our tracks,we followed theirs.It ended up being an awesome trip. Pat

[catch-22]

On corrugations, I switch the drive mode to grass/gravel/snow. I reckon it feels smoother again as it doesn't try to launch off the top of the peaks like when in normal mode.

Or, I could just be dreaming it and having fun using the gadgets.

[Bytemrk]

Must try that! :D

[Dagilmo]

On corrugations, I switch the drive mode to grass/gravel/snow. I reckon it feels smoother again as it doesn't try to launch off the top of the peaks like when in normal mode.

Or, I could just be dreaming it and having fun using the gadgets.

Placebo effect? Either way, your perception is your reality so therefore it is smoother.......:)

I'll give it a go next time also.

[Grentarc]

Placebo effect? Either way, your perception is your reality so therefore it is smoother.......:)

I'll give it a go next time also.
It could be the effect of the lower throttle response?

[catch-22]

It could be the effect of the lower throttle response?



Yeah that's part of it, for sure. The TC as well, probably.

Around bends with corrugations, whilst towing, absolutely no doubt it's better in gravel mode.

[Redback]

Yeah that's part of it, for sure. The TC as well, probably.

Around bends with corrugations, whilst towing, absolutely no doubt it's better in gravel mode.

Yep I do this also when towing, it takes away that tendencey to slide, but it doesn't work on sandy tracks or climbing, for obvious reasons, I found that out the hard way, although in my defence it was my first trip:p

Here I was thinking it was just me, glad I'm not the only one who uses Grass/gravel/snow in certain situations:D

[BobD]

I tried it on gravel when I first got the car but hated the lack of throttle response. I'm all for sliding on gravel!


When I tow I often use sand mode on gravel tracks because of the great throttle response and holding the lower gears a bit more. Especially good on the up and down and round the bend Bungles road.

[RobA]

Having done the Simpson both towing a camper and without at least annually since 2002 I can categorically say a D4 will have no problems at all on those corrugations. This was proven last year when we did the GRR twice and every track, apart from Munja, in the Kimberley all towing and it was the driest season in five years so more corrugations than normal. All good and we kept to on road height unless seriously off road which was rare and when towing or not

Your greatest traction aid in the Simpson is tyre pressures. Get them down to around 18F and 20R if fully loaded. As well and after now covering 57,000km in slightly over 2 years of ownership I reckon in pretty much all conditions when driving dirt roads and tracks we leave it to its own devices. I find sand mode in these situations far too heavy on fuel. The only time I would do that in the Simpson is at the base of a dune then walk it up. The car will do the rest. But you should do a decent sand driving course to actually understand and appreciate how to drive properly in sand regardless of car. As well it is not the corrugations you need to worry about in the Simpson. It is the seriously chopped up tracks over each of the 1,100 dunes caused by numb nuts not lowering their tyre pressures that really cause the problems for traction. Many recommend speed which is not correct. Momentum is the key and that has no relation to going flat out over really rough terrain. Now that is a path to disaster and lots of broken bits. Mostly a D4 well driven will walk up this sort of terrain. A Simpson dune goes like this. Corrugations at the bottom followed by lots of soft and deep wombat holes and just before the top when the numb nuts run out of traction and bury the foot digging a whacking great hole which slowly fills with sand, you end up with a very nice bog hole which is where a snatch strap or maxtrax can come in handy. Crossing is a learning process take it easy and learn. You should be OK after the first 20 dunes and be prepared to not cross first time there is no shame and it ain't a competition. You will reverse down, in low range of course, having tackled it most likely in high but it will be different each time. Then add a small amount more momentum and try again.

Enjoy

Rob

[TuffRR]

I tried it on gravel when I first got the car but hated the lack of throttle response. I'm all for sliding on gravel!
.

Yeah, sand mode on gravel is effectively drift mode with the increased throttle response and reduced TC intervention. Well, as much drift mode as you'd want in a 3.3t 4wd.

[pprass]

"...but many of those Toyo Fans keep telling me that air suspension will not able to handling the long corrugation."

The air suspension on the Discovery is brilliant and I would be pretty safe in saying that it has been tested quite extensively in all conditions including severe corrugations. That is why you don't hear of masses of Discovery owners complaining that they can only travel on bitumen and graded gravel roads!

My experience is short in time, but lengthy in kms having travelled 72,000 kms in the past 18 mnths over sometimes quite severe conditions mainly towing a 3 tonne van.
The most severe was crossing the Great Central Road from Laverton to Yulara - 1,200 kms of tough corrugated road and the last bit after Docker River extremely tough and corrugated. The Discovery did exceptionally well and just glided over the standard corrugations. As others have said though - it allowed me to go faster than I should have and consequently the van suffered and I ended up with a nasty blow out of a rear tyre on the Discovery. However the suspension is so good, that I only realised that I had a flat when I couldn't get any momentum in the soft sand.

[IvanR]

A few yeas ago when travelling on a good dirt road in the Pillbara, the suspension fault light came on. Stopped, rebooted, drove about 10 mts only for the light to come on again :confused:. I then twigged to the real problem, got out and yes an almost flat tyre.. I had not noticed it while driving because of the good suspension. Change tyre and all good again. My fault, could not be bothered to lower tyre pressure for short streach of gravel road (60 ks) between the black top.

Ivan