The Discovery 4 is a second rate tow vehicle

[mowog]

Well according to some experts on a caravan forum the D3/D4 are death traps that should not be allowed to tow. According to these experts the only safe tow vehicle is from Japan? Apparently anything euro is just not up to the task.

I have never read so much rubbish in one place.

Caravaners Forum • View topic - Are WDH necessary when Airbags are fitted to the 4x4 (http://caravanersforum.com/viewtopic.php?f=2&t=19126)

[jonesy63]

I didn't read the linked thread that way at all.

They had a Prado converted to air bags - manually controlled. For that - no computer control of suspension at all - just a manual inflate/deflate option. No self levelling, no pitch/yaw sensors, etc. In that case - yes, a WDH will probably be needed.

I wonder... if it was fitted with HID/Xenon headlights - the suspension conversion would probably render it illegal. :angel::wasntme:

[Disco4SE]

Had a quick read. Did notice that some posts were from Noddie.
Isn't he the cartoon character in the red & yellow car? ;) Say no more.
Cheers, Craig

[TerryO]

No offence Mowog but who really cares what the nong nongs on that site think?

Leave them to pat each other on the back about how smart they were to buy their favoured Crusiers and Patrols. In case you had not noticed a decent percentage of people on that site sound like senile old fools.

There is an old saying that 'ignorance is bliss' which springs to mind.

cheers,
Terry

[dobbo]

Caravan's should be barred.

[Neil P]

Towing with a F250 is good . Caravans are for a certain mind-set.
Each to their own .
The best place to get info on use , is an owner's/user's forum.
I wouldn't ask a Townie if they reckoned the FEL on a JD2000 twenty
series was too lightweight , just as I wouldn't take any real interest in
a general magazine article .

[stig0000]

Caravan's should be barred.

people that drive at 80-90 on the mway with a van should be shot:mad:

[PAT303]

Caravan's should be barred.

Give that man a beer,or three. Pat

[PAT303]

people that drive at 80-90 on the mway with a van should be shot:mad:

Hope you've got lots of money because you'll be doing lots of shooting. Pat

[PAT303]

Towing with a F250 is good . Caravans are for a certain mind-set.
Each to their own .
The best place to get info on use , is an owner's/user's forum.
I wouldn't ask a Townie if they reckoned the FEL on a JD2000 twenty
series was too lightweight , just as I wouldn't take any real interest in
a general magazine article .

Next winter I'll start taking photo's and each week we'll vote on the most overloaded,poorly set-up,most dangerous bikky dipper rig we see.Last winter we overtook a 60 series doing 55 in a 110 zone with both a washer and drier tied to the roof:eek:. Pat

[mowog]

Geez got a slap from the moderator and started an anti caravan thread. I am on a winner here.:eek:

[Tombie]

Where ever Rivers pokes his head there is sure to be a bunch of

Whttp://1.bp.blogspot.com/-Is7CjJLj3WE/TiRaECsSh9I/AAAAAAAAADk/uGTvrPWv8h0/s320/anchor_13-medium.jpgs

[d3viate]

I cannot believe I lost an hour of my life I will not get back reading the caravan towing forum.
Seems we all have to trade down to a 20+ year old vehicle to get a "real 4X4".
Tanks, Helicopters, Desert Rat's in South Africa, if you don't have leaf springs your an idiot, mines bigger than your's, unbelievable.
More people need interesting hobbies or to see a specialist, in saying that, I'm outa here, no not for the specialist !.

[TerryO]

I cannot believe I lost an hour of my life I will not get back reading the caravan towing forum.
Seems we all have to trade down to a 20+ year old vehicle to get a "real 4X4".
Tanks, Helicopters, Desert Rat's in South Africa, if you don't have leaf springs your an idiot, mines bigger than your's, unbelievable.
More people need interesting hobbies or to see a specialist, in saying that, I'm outa here, no not for the specialist !.


x2

cheers,
Terry

[bbyer]

It seems over here in the New World, that the experts do not think the domestic Chev 3500's, Dodge 3500's, or the Ford F350's with their Isuzu, Fiat, or Cat derived 7 litre diesels can cut it either - particularly when passing uphill over 120 kph towing the local version of a road train.:)

[mowog]

Ok I am sorry to those who lost an hour of their life reading the rubbish on the linked thread. But there are a few people here who tow large vans and I thought they needed to know about the dangerous tow vehicle they are using. :eek:

[clubagreenie]

Thread title should read:

caravanersforum.com is a second rate forum.

[PhilipA]

Is this a good start?
Kruger National park September 2010

38851
I particularly like the split system on the back.
Regards Philip A

[jb747]

Crap..and I just bought a Land Rover, because, after lots of research, and driving EVERY possible alternative, I decided it was the best possible mix of tow, offroad, and just nice to drive, of any of the alternatives. And I will admit to being very 'anti' British cars..I wanted another German.

But, I think I'll just enjoy driving my vehicle, and leave them happy in theirs.

I might add though, that I was sent a sticker by a member here, that proclaimed everything else (i.e. not LR) was crap. Put that on this evening.

[101RRS]

And I will admit to being very 'anti' British cars..I wanted another German.



John,

While I think you made the right choice - if you wanted German then why not a Tourag with air suspension - really very similar to a Disco in ability etc.

Garry

[jb747]

While I think you made the right choice - if you wanted German then why not a Tourag with air suspension - really very similar to a Disco in ability etc.

That was in part my original plan. I've also got an Audi Q5, which has a wonderful 3 litre diesel. The Touareg has the same engine coupled to an 8 speed auto (which I presume is the same one as now used in the Audi Q7, and is a very nice drive). So, I waited a long time for VAG to bring the new Torareg to Oz, and I was then extremely disappointed when I had a good look at it.

Nowhere near the interior capacity of the Disco. No 3rd row of seats, and the second row don't even fold properly flat. Most models don't have low range, and are really more mums' school buses than proper offroaders. But, the thing that totally killed it for me...no proper provision for a spare tyre.

Looked at alongside the Disco (we walked from Q7, to Touareg to Disco about 20 times at the Melbourne motor show), the decision to give the LR a go became quite easy.

[Celtoid]

John,

While I think you made the right choice - if you wanted German then why not a Tourag with air suspension - really very similar to a Disco in ability etc.

Garry

A fair while ago there was a thread posted on here with a vid....I'm sure it was on this forum...where a D3 and a Tourag were compared in an offroad situation. It was pretty muddy and slippery.

The vid was all in German with no subtitles so I understood about 4 words......however, the results spoke for themselves...or at least appeared to. D3 spun and slipped but kept going through, time after time. Tourag got stuck every time.

I have no idea how 'fair' the comparison really was...as in driver, tyres, car spec, etc....but the Tourag did not cope at all.

Has there been any 'fair' copmparisons of these vehicles....especially against a D4?

Cheers,

Kev.

[MC D4]

We are new to LR and I was a little concerned about the stories we have heard about buying British but I can tell you the it is the best car I have owned thus far (owned 18 cars of all makes and sizes).

We have just towed a 2.5 ton van 3000 kms over the last 3 weeks and it never missed a beat. Cruised on the highway at 100 kms head wind or no head wind. Over took slower drivers with ease. Averaged 14-15 litres / 100 kms. Handled the winding roads and always felt sure footed.

Once set up we were able to access some great 4wd tracks and dunes with ease. The satnav trace points function was very useful when you head out alone in the wilderness with a wife and baby. We always new that we could venture down the maze of tracks and get back to camp safe.

We got plenty of attention from our neighbours with their landcruisers :eek: when we were hitching up ready to head off each time. No messy WDH set ups to worry about just drop the air bags, reverse with no help from the wife (got to love the reverse camera :D), raise up to access height and then get out connect the bits and pieces.

And not to mention it looks the goods!!!!

[PAT303]

The trouble is MC you have driven different vehicles and do buy different vehicles so you can compare them directly,many people don't do that yet still have lots to say.Many people buy a cruiser and big van having never driven anything bigger than a camry and all of a sudden they are know it alls in regards to towing and driving but simply have no idea,I'm still waiting for someone to explain how a van lifts the front wheels off the ground,200 kg's on the ball can somehow lift the front up even though there's a cast iron diesel engine,gearbox/transfer case and front diff sitting there wieghing the best part of a tonne holding it down. Pat

[StephenF10]

...I'm still waiting for someone to explain how a van lifts the front wheels off the ground,200 kg's on the ball can somehow lift the front up even though there's a cast iron diesel engine,gearbox/transfer case and front diff sitting there wieghing the best part of a tonne holding it down. Pat

The concern is not that the front wheels will be lifted off the ground but that enough weight will be taken off to affect steering and braking. I agree that, in the case of a heavy 4WD, there should still be plenty of weight over the front wheels to stay safe.

Stephen.

[mowog]

When I get some time I am going to see how much weight I loose from the front wheels. With the van attached.

[brad72]

Land rover is quite clear that an equalising or other forms of WDH should not be used with a D4 when towing. The air suspension is designed to take care of the load and i would guess the computer would get pretty confuced with a WDH fitted.

They do say you need to take into account the total weight on the rear axel, which includes passenges and luggage in the back. This would obviously affect the ride if you have a few hundred kg's on the towbar and a fully ladden boot space.

This is how land rover recommends checking the weight over the front wheels for safe driving when towing heavy loads. Once you have done this once with your van or boat everything should be fine


Vehicle weights
When loading a vehicle to its maximum (GVW),
take account of the load distribution to ensure
that axle loads do not exceed the permitted
maximum values. It is your responsibility to
limit the vehicle load in such a way that neither
the maximum axle loads nor the GVW are
exceeded. The most accurate method of
determining load distribution is by using a
public weighbridge.
Nose weight must be the greater of 50 kg
(110 lb) or 7% of the actual trailer laden
weight, up to the maximum tow hitch load.
Nose weight can be measured using a
proprietary brand of nose weight indicator.

Plus


If the vehicle is loaded to the Gross Vehicle Weight (GVW), the nose weight
is limited to 150 kg (330 lb). If a trailer with over-run brakes is used the
nose weight can be increased up to 250 kg (550 lb) total nose weight.

However, vehicle payload

must be restricted by at least the same weight to


ensure that the GVW and rear axle weights are not exceeded. See


TECHNICAL SPECIFICATIONS (page 263).

[Redback]

Even with our camper (1.4t) I notice a difference in the front, the steering can be vague and light if you don't even things out, once I put air in the bags(coilrite helper bags) it raises the rear back to even and the steering becomes better and less vague, but it is still not as good as it is without the trailer on and my ball weight is under 90kg.

You can notice that the front of the car is higher than it should be, and when you start putting air in the bags, you can see the front lower as the rear comes up, I've been towing for a long time and I can say that the most significant thing that contributes to an unstable setup is too much weight over the ball.

Keep the ball weight down and tow something that is 1 ton under your max towing capacity.

Baz.

[ozscott]

I know what LR says about WDH not being used (because it interferes with the air suspension and one system fights against another). I have also read the thread where at least one member here (a very experienced member with respect to LR and towing) went 200 series because he wanted to use a WDH versus a D4. I am yet to understand however how the vehicle itself (by itself) can re-assert weight back to the front end with a very heavy van on, versus the weight being levered back on using a WDH - its the lever effect which surely air bags alone cannot do.

If it were possible to lever up using air bags alone to the same extent as the forces attained by a WDH then merely using poly bags on max pressure would do this, but they dont (see Redback above and my experience towing a 2 tonn boat with poly bags - restores some feel and weight to steering and brake effect of the front end, but not as good as having no weight ont he back by any means...). Having active bags does not make any difference to the mechanical force going on here, so how does air suspension restore weight over the front axle like WDH's have done for some many years. Please dont flame me with old tech...shake the head...they just dont get it. What this is about is trying to understand how it is possible for air suspension bags alone to REPLICATE OR BETTER a WDH set up.

Cheers

[101RRS]

Land rover is quite clear that an equalising or other forms of WDH must not be used with a D4 when towing.


Is that totally true or the handbook say something like: Caution: An equalising or other form of weight distributing hitch should NOT be used on your vehicle.

Should not and Must not have very different meanings. Should not means it is not Landrover's preferred option but it can still be used if necessary. Must not means it must never be used under any circumstances.

I don't believe Landrover has actually said that WDHs must never be used but only recommends against their use. (noting they also recommend not using any other towing gear except landrovers)

Garry

[brad72]

Would i be wrong in saying that a WDH mearly (used as a loose term) bandaids wrong suspension type, badly loaded car or incorrect tongue weight that is outside the vehicle manufacturers specs?

But is saying that not many of us have access to a nose weight indicator to ensure everthing is loaded correctly every time we change something to ensure correct driving charateristics.

[mowog]

The LC 200 owners are in a no win situation that many ignor. Toyota say a WDH is required but only a Toyota approved WDH should be used. There are none approved by Toyota.

[PAT303]

The problem is just what Brad has said,WDH are a bandaid solution.I used to regulary two 2 tonnes with my defender but I fitted HD rear springs and it never changed the way it drove.My vehicle dropped an inch or so but thats it,no wandering or nervous steering,if you think about how WDH work you can also see how fitting taller stiffer springs with dampers to match would do a better job,fitting a WDH to a vehicle with it's bum on the ground is plain stupid,just fit the correct suspension. Pat

[ozscott]

If the nose weight cannot be reduced or reduced safely then you are stuck with it. It does not matter whether you can get your vehicle to stock height using stiff springs or air bags - the weight levers the back of the vehicle causing weight to come off the front. You cannot lever that back up without WDH's as I see it. I know guys who tow heavy all the time and even with rear suspension that is HD and does not drop when the van is on, they use WDH to restore weight to the front. I am not asking about weak or poorly maintained suspension.

Cheers

[PAT303]

From where I sit the wieght changes as the suspension compresses and then rebounds so the rig pogo's at it's center and the WDH tries to control that,which is the spring and dampers job. Pat

[Len Hall]

When I told our caravan serviceman I was going from a 79 Series Cruiser Ute to a D4 he was worried about the WDH issue. He phoned his mate who is the manager of a Hayman Reece store, mate said that they have looked at manufacturing something for the D4 but when they got hold of one they realised that they could do nothing to improve it, in his words "It is simply the best system on the market".

[gghaggis]

Seriously guys, we have argued this ad-nauseum on this forum. Please search first - we've covered EAS versus WDH, natural vibration characteristics of WDH, why they're seen as a "perfect" solution, why they're not etc etc etc

And you don't need to ponder the semantics of "should not" versus "must not". Land Rover Australia will not honour a warranty claim on your EAS system if you use a WDH system. That should be all you need to consider.

Cheers,

Gordon

[101RRS]

And you don't need to ponder the semantics of "should not" versus "must not". Land Rover Australia will not honour a warranty claim on your EAS system if you use a WDH system. That should be all you need to consider.

Cheers,

Gordon

All well and good but if the issue goes on to court the wording will be carefully considered.

Garry

[chuck]

We are bulding a new facility for the Trimas Corporation which is Hayman Reece the MD drives a D4 with stock LR towgear.

We met & he asked me about my serious tyres!!!

Regards

[Busman]

Pure and simple.
The D3 & D4 are quite simply an amazing tow vehicle.
I have towed my 3 ton + boat with ease, and feel very safe.
Seems the minority think otherwise.
Who cares.
We all know the D3/D4 combination is certainly are up to the task and more.

[John W]

Would i be wrong in saying that a WDH mearly (used as a loose term) bandaids wrong suspension type, badly loaded car or incorrect tongue weight that is outside the vehicle manufacturers specs?

But is saying that not many of us have access to a nose weight indicator to ensure everthing is loaded correctly every time we change something to ensure correct driving charateristics.

Yep I think you are wrong.

Not sure what all the concern is here as a D4 is a whole lot different to a Prado on coils with supplementary coilrite in spring air bags. I doubt too may in the caravan post know anything of D4 suspensions and would not be having their discussion with a D4 suspension in mind. That prado should have a WDH with anything other than a very light van but a D4 (with 4 post electronic air bags) should not, end of story. True the D4 can not lever weight onto the front but it will be good enough so long as the driver understands the limitations of the rig. And before anyone gets sensitive about the use of the word "limitations" in a D4 post, all rigs have limitations. It just happens that a limitation of a D4 suspension is that it does not suit a WDH.

[PAT303]

Maybe what we really need is for a D4 owner to sit his front wheels on a wieght bridge and hitch/unhitch a van and see for sure without guess work what the load is on the front wheels. Pat

[mowog]

Maybe what we really need is for a D4 owner to sit his front wheels on a wieght bridge and hitch/unhitch a van and see for sure without guess work what the load is on the front wheels. Pat

When I get a chance I will do this.

I need to see what our van weighs now that it is setup in full trip mode.

[TerryO]

Yep I think you are wrong.

Not sure what all the concern is here as a D4 is a whole lot different to a Prado on coils with supplementary coilrite in spring air bags. I doubt too may in the caravan post know anything of D4 suspensions and would not be having their discussion with a D4 suspension in mind.

That prado should have a WDH with anything other than a very light van but a D4 (with 4 post electronic air bags) should not, end of story. True the D4 can not lever weight onto the front but it will be good enough so long as the driver understands the limitations of the rig. And before anyone gets sensitive about the use of the word "limitations" in a D4 post, all rigs have limitations. It just happens that a limitation of a D4 suspension is that it does not suit a WDH.

In actual fact these people on the other sites are spending quite a bit of time bagging D3/4's suspension as being rubbish and badly designed because it doesn't use a WDH. But they are also comparing D3/4's as being 'lightweight tow vehicles' unlike Patrols and Crusiers which they consider as heavyweight tow vehicles. The big joke is most diesel Patrols are auto's so can only tow legally 2.5 ton, yet they often decide to ignore this fact.

Is it a limitation for D3/4 not to have a WDH? I would say it was if the suspension isn't designed properly and the vehicle operated better with one, but there is nothing to show that this is the case. So if that is the case then it is not a limitation.

cheers,
Terry

[But 'n' Ben]

Pat303 asked for some figures, and I just happen to have some available. Hope they suffice?
New D4, with full fuel, and driver weight at 80Kgs, I put the vehicle on our local Weighbridge. Axle figures were:-
Front_ _ _1.320.
Rear_ _ _ 1.340.
This gives a Kerb Weight of 2.660, which is 77 kgs over the book of 2.583, don't know why this was so?
We are presently approaching the end of our first trip, and with a heavy Caravan hitched up. and at the beginning, I put the whole rig, all loaded up, on the Weighbridge again. These are the figures, but now the car has the addition of, ARB steel Bull Bar, LR Cargo Barrier, Floor mats, 3" S/Steel side tubes, 18" Rims.

GCM 6.10. ie; GVM + ATM.
GTM 2.90 this is discounting the Ball Weight.
ATM 3.20 this is total mass, including Ball Weight.
Ball Weight .30.
D4 GVM, unhitched, 2.90.
D4 hitched, including ball weight 3.20.
Front Axle 1.26.
Rear Axle 1.94.
Although the D4 was 40 kgs below limit, hitched up, the rear axle was over the top by 85 kgs, so I had to make a few changes to loading before proceeding further.
All in all, these figures have given me 'Food for Thought' regarding safe, and legal loading of the 'Combination'. Maybe I should not carry the 60 Lts of Diesel on the drawbar. This would reduce Ball Weight, which would take a bit off the vehicle, and also the Caravan.
Interesting to note that, although the Bull Bar is supposed to add 35 kgs to front axle and with my 60 kgs wife, plus cargo on the rear seats, adding a slight bit to front loading, that the 300 kgs Ball Weight lifts 60 kgs off the front loading.
Pick through these figures Guys, somebody else's slant would be appreciated.
Don.

[John W]

In actual fact these people on the other sites are spending quite a bit of time bagging D3/4's suspension as being rubbish and badly designed because it doesn't use a WDH. But they are also comparing D3/4's as being 'lightweight tow vehicles' unlike Patrols and Crusiers which they consider as heavyweight tow vehicles. The big joke is most diesel Patrols are auto's so can only tow legally 2.5 ton, yet they often decide to ignore this fact.

Is it a limitation for D3/4 not to have a WDH? I would say it was if the suspension isn't designed properly and the vehicle operated better with one, but there is nothing to show that this is the case. So if that is the case then it is not a limitation.

cheers,
Terry

Thanks Terry I admit that I did not read more than the first couple of pages of the posts. If they are bagging the D4 then they are fools. I would still argue though that if the electronic controlled D4 suspension could handle a WDH then it would be an added advantage but that does not take anything away from the fact that a D4 is more than adequate with a big van.

[ozscott]

Thanks Don. Excellent post mate.

So it's settled then that auto controlled bags still allow substantial weight to come off the front wheels (with negative effects on braking in particular) and only a wDh (if it could be used in this case) would be able to lever the weight back onto the front?

Perhaps the caravan forum blokes when talking about the cruiser being a heavyweight tower were talking of them cruisers weight - more the merrier. The kerb weight on any of these big wagons is not an issue at lower levels but at over 3k say every bit of extra kg of the tow vehicle is a good thing.



Cheers

[Redback]

Thanks Don. Excellent post mate.

So it's settled then that auto controlled bags still allow substantial weight to come off the front wheels (with negative effects on braking in particular) and only a wDh (if it could be used in this case) would be able to lever the weight back onto the front?

Perhaps the caravan forum blokes when talking about the cruiser being a heavyweight tower were talking of them cruisers weight - more the merrier. The kerb weight on any of these big wagons is not an issue at lower levels but at over 3k say every bit of extra kg of the tow vehicle is a good thing.





Cheers

Personnally I'm not convinced a WDH will put weight back onto the front axle as much as they are reported too, There is still all that weight over the back axle..

Would be interested to see (as an excample only) a WDH attached to the D4 above and the same test preformed again, that would convince me once and for all.

Or a comparitive test using a different vehicle.

Anyone got a WDH they can lend:D

Baz.

[PAT303]

That would give a definitive answer as to wether a WDH did lever weight forward,if it did it'll be a know brainer as to why they rip towbars off. Pat

[Graeme]

Would be interested to see (as an excample only) a WDH attached to the D4 above and the same test preformed again, that would convince me once and for all.
A 4WD mag some time ago did a tow test with several vehicles. They fitted a WDH to each vehicle including a D3, although they had to play around with the D3's adjustment to get the setup to ride properly and not compete with the air suspension. I suspect the WDH provided only a small transfer from the rear wheels because of conflicts with the air suspension's levelling if too much weight was tried to be lifted off the rear. The tow test was not repeated without a WDH because the assumption was that it was best to have a WDH fitted.

A WDH on the D4 could interfere with trailer stability assist's ability to detect and correct sway, along with the usual disadvantage when travelling over ruts and affecting ride height thus could compete with the supension's desire to self-level. The minimal weight transfer from the front even with the maximum ball weight is a small enough percentage of the D3/4's front axle weight that I'd expect it to be inconsequental. The air suspension will keep the vehicle at its normal ride height all round and the suspension geometry will therefore be normal, unlike vehicles with steel springs.

[Redback]

A 4WD mag some time ago did a tow test with several vehicles. They fitted a WDH to each vehicle including a D3, although they had to play around with the D3's adjustment to get the setup to ride properly and not compete with the air suspension. I suspect the WDH provided only a small transfer from the rear wheels because of conflicts with the air suspension's levelling if too much weight was tried to be lifted off the rear. The tow test was not repeated without a WDH because the assumption was that it was best to have a WDH fitted.

A WDH on the D4 could interfere with trailer stability assist's ability to detect and correct sway, along with the usual disadvantage when travelling over ruts and affecting ride height thus could compete with the supension's desire to self-level. The minimal weight transfer from the front even with the maximum ball weight is a small enough percentage of the D3/4's front axle weight that I'd expect it to be inconsequental. The air suspension will keep the vehicle at its normal ride height all round and the suspension geometry will therefore be normal, unlike vehicles with steel springs.

Yes I agree, I was only thinking of weighing the front and rear axles, just to see if the WDH did put weight back to the front as much as they claim, just a comparison.

No driving, attach it at the weighbridge.

Baz.

[scrambler]

Back when this thread started I did some online checking. There is stuff-all proper research on towball weights etc. The 10% seems to be something someone dreamed up. There was some decent work done back in the 70's, so modern suspension etc may have an impact but I think the generalities apply.

The bottom line was that there was always a benefit to the tow vehicle being heavier than the towed trailer, that central mass loading in the trailer/van was better than distributed (so caravans particularly bad) and that the two major problems of tow vehicle stability and trailer stability required opposite solutions with ball weight and WDH. Contrary to what I would think, WDH made the towed vehicle harder to drive and more likely to jacknife in a corner. The only solution was to lower front tyre pressure. The benefit to the WDH was in preventing trailer sway. Another way of saying this is that the WDH had the same vices and benefits of adding further towball weight. Go figure...

In the weight range of a Disco 4 and assuming an 18 foot, 1.8T van you would want about 15% tow ball weight without a WDH (270kg). See page 130 of the linked PDF:
http://www.edccorp.com/library/TechRefPdfs/EDC-1082.pdf

According to the research "there is definitely an optimum hitch load for each tow car and trailer combination." Now to find it!

[TerryO]

Thanks Don. Excellent post mate.

So it's settled then that auto controlled bags still allow substantial weight to come off the front wheels (with negative effects on braking in particular) and only a wDh (if it could be used in this case) would be able to lever the weight back onto the front?

Perhaps the caravan forum blokes when talking about the cruiser being a heavyweight tower were talking of them cruisers weight - more the merrier. The kerb weight on any of these big wagons is not an issue at lower levels but at over 3k say every bit of extra kg of the tow vehicle is a good thing.
Cheers


You are assuming it has a negative effect on braking Scott, the amount of weight reduced on the front axle wasn't massive, only about 100 kgs if I read correctly. Which is roughly a 10% reduction in front end weight.

Having 1.2 ton of weight on the front wheels is still a very substantial amount of weight, just because there is 1.9 ton on the rear doesn't automatically mean the vehicle is unstable or loses braking effectiveness.

If it did then people would be reporting that their D3/4's are handling poorly when towing. To date I have not seen one comment saying this.

Has anyone else seen a comment from a D3/4 owner saying they have experienced handling and braking woes when towing large traliers or vans?

cheers,
Terry

[CraigH]

Correct me if I'm wrong but isn't Land Rover the only manufacturer that has a demonstration video of its Trailer Stability Assist?

To the average punter this shows that LR put the research and development into engineering a superior tow vehicle and a tow bar is not just a add on after thought.

I know this was a big selling point along with its 3500kg towing ability that sold my parents on one to tow their van not just safely but in comfort.

Craig

[gghaggis]

There seems to be a dogged determinism to keep this 'wdh vs eas' debate alive??

Despite the facts that the manufacture tells us which is preferred, the owners that tow with both systems tell us which system they prefer, we still have to listen to the wisdom of a bunch of Toyota owners????

Weighbridge figures are for a STATIC system. On an undulating or bumpy road (which seems to be most of them), the leveraging effect of a WDH system can (and probably always does) intensify and vary the weight redistribution effect. Not good .....

Cheers,

Gordon

[Rockylizard]

Gday...

Now THAT makes real sense ... when I had Cruisers etc I would never have towed without a WDH because it made everything 'feel and sit right'.

The D3 is incredibly stable in all conditions with my van on the back without a WDH. I was dubious when I first got the D3, but after 30,000km of towing my big van over outback QLD and NSW for the past two years on all sorts of roads - both minor and major, majority sealed but some dirt - the D3 is the most stable vehicle I have towed with.
Cheers
John

[TDV6]

The July 2009 Caravan and Motorhome issue has an article on WDH and ordinary (non SLS) vehicles and, also a D3. The conclusions were a towball weight of from memory 140kg resulted in a 60kg lighter load on the front wheels which still left a weight of grater than 1100kg on the front tyres of a D3, If I remember their conclusion correctly, the D3 SLS took care of everything and a down-force of 1ton plus on the front wheels maintained directional control.

I have towed my three ton van without a WDH around OZ, all without any problems. Loading our van with approx 200kg plus nose weight works well for me, as does the tandem axle, now if only I had air suspension on the van to help level it when camped on a creek bank out in the bush :)

Ryall

[Wirraway]

Have to agree with John about the stability of the Discovery 3/4. I've never used a WDH on either the current D4 or any previous vehicles - maybe horse trailers tow differently? My summation of this whole WDH issue is;
- Yes a WDH has theoretical benefits, you can't argue with the science. The level of benefit will vary greatly depending on input parameters.
- Yes you'd be mad to tow a large trailer without one on some vehicles
- Land Rover say don't use one on a D3/4 so you shouldn't.
- As long as the loads are within stated limits then the D3/4 is a safe tow vehicle
Do I think a WDH could improve the towing capability of the D3/4? Maybe, but we'll never know. I couldn't be happier with the way the D4 tows and don't think it can be improved much. Guess we'll just have to live with an almost perfect tow vehicle.;)

[Tombie]

Actually in a dynamic situation you can argue the science!

I'd be (and I am) more concerned with people's desire to tow 3000+ kg of Griswald family roadblocker!

And the heavy, overdone mass that van manufacturers are building!

It's ridiculous!

Sent from my iPhone using Forum Runner

[PAT303]

^^on a car license with no heavy vehicle experience.:mad: Pat

[PAT303]

Gday...

Now THAT makes real sense ... when I had Cruisers etc I would never have towed without a WDH because it made everything 'feel and sit right'.

The D3 is incredibly stable in all conditions with my van on the back without a WDH. I was dubious when I first got the D3, but after 30,000km of towing my big van over outback QLD and NSW for the past two years on all sorts of roads - both minor and major, majority sealed but some dirt - the D3 is the most stable vehicle I have towed with.
Cheers
John

Enough said. Pat

[TerryO]

I'm not saying this is right or wrong because frankly I don't know, but an older ex NSW's coppa I know well reckons that you need a Medium Rigid truck license (from memory) if you drive any vehicle on NSW's roads with a greater combined mass then 4.5 ton (again from memory).

Is this right or wrong? If it is then most large van / 4x4 combo's would easilly be breaking the law. If it isn't then what is the law on car licenses and towing?

cheers,
Terry

[Graeme]

Only a car licence (class C) is required - GVM not GCM. The following is from the RTA web-site.
Car

A 'Class C' licence covers vehicles up to 4.5 tonnes gross vehicle mass (GVM)
GVM is the maximum recommended weight a vehicle can be when loaded.
A 'Class C' Licence allows you to drive cars, utilities, vans, some light trucks, car-based motor tricycles, tractors and implements such as graders.
You can also drive vehicles that seat up to 12 adults, including the driver.
Rigid vehicle licences


Different licence classes are required by drivers of rigid vehicles:

A Light Rigid 'Class LR' covers a rigid vehicle with a GVM of more than 4.5 tonnes but not more than 8 tonnes. Any towed trailer must not weigh more than 9 tonnes GVM. Also includes vehicles with a GVM up to 8 tonnes which carry more than 12 adult including the driver and vehicles in class 'C'.

[Redback]

^^on a car license with no heavy vehicle experience.:mad: Pat

AND, it is illegal on a car licence if the combined weight of the 4WD and Trailer you are driving exceeds 4.5t in NSW.

Baz.

[clubagreenie]

I have achieved a new forum record for me. Banned in 18min, user name deleted.

Apparently they don't like having all these things discussed pointed out.

:banana::ehigh5:

[TerryO]

Back on topic for a moment gents;

After all the BS on other forums and some confusion even on here I thought it would be best to go directly to the horses mouth (sorry to Gary from Hayman Reese no offence meant) and ask the techo's at Haymen Reese what their thoughts are on D3/4's and WDH's and are they needed. This was the emailed responce I got back this morning from Gary in their technical department.

After reading what Gary wrote as far as I'm concerned it is the end of the debate. Feel free to repost this reply elsewhere if you think it would help to educate the luddites.


Hello Terry,
Thank you for your enquiry regarding towing with the Discovery 3/4. We are lead to believe that the majority of vehicle manufacturers recommend that a WDH should not be used on their vehicles that have Self Leveling Suspension. This recommendation should be adhered to, if for nothing else other than for warranty reasons of the vehicle.
In the case of the Disco 3 and 4 I completely agree with the recommendation, these vehicles appear to tow better when the WDH is not installed, the SLS on these vehicle does a very good job at correctly distributing the ball load being applied across both axles.

I hope this information has been useful to you and if I can assist you any further please feel free to contact me.


Gary Gardiner
Towing Technical Support Rep. QLD

Cequent(tm), a division of TriMas Corporation Pty Ltd

E-Mail: ggardiner@trimas.com.au (ggardiner@trimas.com.au) Cequent
Mobile: PO Box 4050
Phone: Dandenong South VIC 3164
Fax: Australia


Cheers,
Terry :D

[33chinacars]

Thanks Terry

Had a simular conversation with a tech at Caulfield Caravan Show about my R.R. WDH not recomended with SLS. Even tho I had fronted up with money to buy . Told to save my money for something else.

As for licences if I can remember rightly in Vic on ordinary car licences up to a GVM of 4.5t & GCM of 9t. Checked this out a couple of years ago when looking at 5th- wheelers

Gary

[TerryO]

I went one step further and rang Gary from Haymen Reese technical departmet just now and asked him several more questions on WDH's and D3/4's and to make sure he was cool with me posting his email. He was very accomodating and helpful to say the least.

One thing he said that put a smile on my face was, he believes 99% of vehicles when towing a heavy load need or would benefit from having a correctly adjusted WDH fitted.

He added, the only vehicle he has found so far that does not need a WDH is the D3/4/RRS as the LR SLS system is very good at distributing weight across both axles.

Might be best not to tell the ToyoPooter owners on the various van sites about this or they might have an even bigger dummy spit and go burn down the Hayman Reece factory. ;)


cheers,
Terry

[Tombie]

I have achieved a new forum record for me. Banned in 18min, user name deleted.

Apparently they don't like having all these things discussed pointed out.

:banana::ehigh5:

What did you post? ;) Have you got what you wrote?

[PAT303]

What did you post? ;) Have you got what you wrote?

Yeh sounds good,nothing like gossip.:p Pat

[clubagreenie]

I basically took everything from here, put in line with everything there and compared, against their "learned opinions" (there's one term they didn't like). Pointed to the LR video of the tow assist demo etc. Probably the most damming was the apples vs oranges comparison of full EAS disco vs A/market prado where apparently the prado is better prior to the airbags and after the disco isn't available for comment.

I added comments, which were in response to questions I posed on the subject (taken from their opinions), from a friend who works at Renault F1 and was told by the banner that what would he know.

My previous record was 22min.

[elsey]

I have been watching this discussion from the outset with interest and with some amusement.

The link below should add a bit of weight (play on words) to the reply that TerryO received from Gary Gardiner from Haymen Reese and his faith in the Discovery 4's ability to tow safely without the aid of a WDH and the LR SLS.

Land Rover Discovery 4 Trailer Stability Assist Video - YouTube

TerryO thanks for taking the trouble to contact Gary and posting his reply.

Lou...

[Lotz-A-Landies]

If the vehicle is loaded to the Gross Vehicle Weight (GVW), the nose weight is limited to 150 kg (330 lb). If a trailer with over-run brakes is used the nose weight can be increased up to 250 kg (550 lb) total nose weight.

However, vehicle payload must be restricted by at least the same weight to
ensure that the GVW and rear axle weights are not exceeded.
One wonders why over-run brakes would allow an increase in tow ball weight over any other sort of safer more efficient trailer brakes? :confused: Or are they talking about any trailer brakes?

[Graeme]

AND, it is illegal on a car licence if the combined weight of the 4WD and Trailer you are driving exceeds 4.5t in NSW.

Baz.
No, GVM is the vehicle's max weight and does not include any trailer. GCM is gross combination weight and refers to articulated prime mover with trailer combinations with turn-tables such as semi-trailers and B-doubles but not a rigid truck with a trailer in tow.

[Lotz-A-Landies]

No, GVM is the vehicle's max weight and does not include any trailer. GCM is gross combination weight and refers to articulated prime mover with trailer combinations with turn-tables such as semi-trailers and B-doubles but not a rigid truck with a trailer in tow.That's interesting because VSI 18 specifies: "Mass Limits Combinations including a towing vehicle with a GVM up to 4.5 tonnes
The laden mass of the trailer must not exceed:
• The capacity of the towing attachment (the towbar), or
• the maximum laden mass of the trailer, or
• the maximum towing mass specified by the manufacturer of the towing vehicle.
Where the manufacturer of the towing vehicle has not specified the maximum towing mass,
the following maximum towing mass applies:
• 11/2 times the unladen mass of the towing vehicle, providing the trailer is fitted with brakes that
are working properly, or
• the unladen mass of the towing vehicle.
The mass of any combination must not exceed:
• The towing vehicle’s Gross Combination Mass (GCM)."
http://www.rta.nsw.gov.au/registration/downloads/vsi/vsi18_rev2.pdf
All before it gets to vehicles over 4.5 Tonnes.

Even the graphic on the VSI 18 shows a 6X4 pantec truck with a dog trailer and a station wagon with a tandem pig trailer(caravan) neither of which are fifth wheelers.

Want more? We'll give you more!
RTA Publication: Towing trailers - Things you should know.
"The GCM is the gross combination mass of the car and loaded trailer."
http://www.rta.nsw.gov.au/registration/downloads/2005_10_towingtrailers.pdf

[Graeme]

• The towing vehicle’s Gross Combination Mass (GCM)."
And what does LR state is a D3/D4's gross combination mass?

You're confusing a vehicle's GVM with a vehicle and trailer combination mass. The subsequent paragraph refers to vehicles with a GVM in excess of 4.5T, not a GCM in excess of 4.5T.

edit:
Those diagrams refer to dimensions not GCMs, but yes, GCM is used for more than just trucks with turntables.

[Lotz-A-Landies]

No, GVM is the vehicle's max weight and does not include any trailer. GCM is gross combination weight and refers to articulated prime mover with trailer combinations with turn-tables such as semi-trailers and B-doubles but not a rigid truck with a trailer in tow.

And what does LR state is a D3/D4's gross combination mass?

You're confusing a vehicle's GVM with a vehicle and trailer combination mass. The subsequent paragraph refers to vehicles with a GVM in excess of 4.5T, not a GCM in excess of 4.5T.

edit:
Those diagrams refer to dimensions not GCMs, but yes, GCM is used for more than just trucks with turntables.Sorry I am confused, when you stated "GCM is gross combination weight(mass) and refers to articulated prime mover with trailer combinations with turn-tables such as semi-trailers and B-doubles but not a rigid truck with a trailer in tow" I thought you were referring to the combined mass of the towing vehicle and the trailer (GCM) was a term only applied to vehicles with turntables.

I therefore inserted RTA documents that referred to vehicles in weight classes (GVM) where the D4 would sit. i.e. vehicles less than 4.5tonnes GVM and the descriptions included GCM.

My humblest appologies for getting my GCMs and GCMs mixed up.

[Graeme]

I therefore inserted RTA documents that referred to vehicles in weight classes (GVM) where the D4 would sit. i.e. vehicles less than 4.5tonnes GVM and the descriptions included GCM.
You're correct. I wasn't aware that the RTA had used GCM in reference to cars and their trailers in addition to prime movers and their articulated trailers, incorrectly relying on my exposure to truck registration and licencing requirements up to class HC.

However the 4.5T GVM limit is referring to only the tow vehicle and doesn't include the trailer. A D4 can tow up to 3.5T because its tow-bar is limited to 3.5T and LR have stated on the compliance application (RVD1 record) a max tow weight of 3.5T and that weight is not more than 1.5 times the D4's tare weight.

[Lotz-A-Landies]

<snip>
However the 4.5T GVM limit is referring to only the tow vehicle and doesn't include the trailer. A D4 can tow up to 3.5T because its tow-bar is limited to 3.5T and LR have stated on the compliance application (RVD1 record) a max tow weight of 3.5T and that weight is not more than 1.5 times the D4's tare weight.Absolutely what I was discussing, and if I posted the entirety of the available documents, we would find that the RTA does specify the GCM is specified by the vehicles manufacture. It is only in the cases where there is no manufacturers GCM are the relevant formula applied again providing that the GTM is equal to or less than that specified by the tow bar manufacturer.

[Redback]

No, GVM is the vehicle's max weight and does not include any trailer. GCM is gross combination weight and refers to articulated prime mover with trailer combinations with turn-tables such as semi-trailers and B-doubles but not a rigid truck with a trailer in tow.

Tell that to the Police in Hurstville, who refused one of our drivers from proceeding while driving the Disco 3 and trailer combination of over 5 tonne at our work, a driver with an MR Licence had to be sent to retrieve the vehicle and trailer, loaded with a street sweeper and gear.

He stated that the combined weight (GCM) of the car and trailer exceeded 4.5t and as such exceeded the max weight a person with a car licence can operate.

Which means it is illegal.

Baz.

[Redback]

OK I rang the RTA, they state they you can tow up to the WHATEVER THE MANUFACTURER state as their GCM (eg) if LR state their GCM is 6000kg, then that's the max allowed as a combined weight allowed for that vehicle and loaded trailer, but they still couldn't tell me if you could do it on a standard car licence:eek:

The RTA are very vague to say the least:angel:

Baz.

[Graeme]

Tell that to the Police in Hurstville, who refused one of our drivers from proceeding while driving the Disco 3 and trailer combination of over 5 tonne at our work, a driver with an MR Licence had to be sent to retrieve the vehicle and trailer, loaded with a street sweeper and gear.

He stated that the combined weight (GCM) of the car and trailer exceeded 4.5t and as such exceeded the max weight a person with a car licence can operate.

Which means it is illegal.

Baz.
It means that the officer thought it was illegal. I'd say that the officer should therefore give me a ticket and I'd see him in court if it got that far before an officer who actually knew the regulations intervened. If he arrested me then it would be sorted out at the station very quickly.

Edit: Actually because I have an HC licence he would have let me go anyway.

[Graeme]

OK I rang the RTA, they state they you can tow up to the WHATEVER THE MANUFACTURER state as their GCM (eg) if LR state their GCM is 6000kg, then that's the max allowed as a combined weight allowed for that vehicle and loaded trailer
Yes, my earlier comment regarding 1.5 times the tow vehicle tare weight is the rule in the absence of a manufacturer's maximum. My RRC can tow 4T. LR reduced the limit to 3.5T for vehicles fitted with ABS.

[33chinacars]

A lot of the big Chev Silverado's dually's were down graded to a GVM of 4.499 t so that they could be driven on a standard car licence. Still able to tow a 4.5t trailer on same licence. Max 9 t GCM

[Redback]

It means that the officer thought it was illegal. I'd say that the officer should therefore give me a ticket and I'd see him in court if it got that far before an officer who actually knew the regulations intervened. If he arrested me then it would be sorted out at the station very quickly.

Edit: Actually because I have an HC licence he would have let me go anyway.

Doesn't really affect me either as I have HC licence as well, I'm not saying the combination isn't legal, which it obviously is legal, but can it legally be driven by a holder of a standard car licence, because it doesn't state (that I can find) that it includes combinations of over 4.5t (ie) car and trailer combinations, it just says you can't drive vehicles weighing more that 4.5t on a car licence, which means it's one of those grey areas.

Baz.

[Graeme]

Baz,
I gather you've been here: A national system of driver licence classes has been introduced in NSW. (http://www.rta.nsw.gov.au/licensing/licence_classes.html)
Whilst it doesn't mention trailers being towed by the class C licence vehicle, the other licence classes spell out what they cover and they're all for when a vehicle's GVM exceeds 4.5T, with trailer GVMs seperately noted. It would help if the RTA mentioned trailers with the class C vehicles to avoid ambiguity, both for the public and surprisingly for some police officers too. I don't know if the note "All States and Territories in Australia have a uniform driver licence system" helps or not.

[joeT]

A lot of the big Chev Silverado's dually's were down graded to a GVM of 4.499 t so that they could be driven on a standard car licence. Still able to tow a 4.5t trailer on same licence. Max 9 t GCM

WRONG VERY WRONG.

A car lic. Allows 1 to drive to a MAXIUM weight of 4.5t.. GVM AND GCM Regardless of it's tow capabilities. If u wish to drive OR tow Anything over 4.5t u must have the Correct license for that weight division.
Example: if 1 was to have a HC lic. (single trailer combination or truck and dog combination where the trailer can carry more mass of then towing truck) but was driving a truck with a GCM 140 (3 trailer road train)t just doesn't mean he can just put on those 2 extra trailers " just " cause the truck they are driving is ABLE as he doesn't have the required MC lic.

Just cause something stated that it has a tow weight of ...... Doesn't just mean YOU can drive it.
Cheers Joe

[mowog]

Licence classes, codes and conditions (Department of Transport and Main Roads) (http://www.tmr.qld.gov.au/Licensing/Getting-a-licence/Classes-and-codes.aspx)

"C (car)
a moped (2 or 3 wheeled motor vehicle)
a motor vehicle (other than a motorbike) of not more than 4.5 t GVM, built or fitted to carry no more than 12 adults, including the driver, with or without a trailer
a specially constructed motor vehicle† of not more than 4.5 t GVM, with or without a trailer."

From Queensland Transport. To me that says the car can be 4.5T and still tow a trailer.

[joeT]

From vic law.

A light ridged lic can not exceed 8t.GCM.. So WHY then would a standard car lic be able to have a GCM of 9t Which is GREATER then a light rigid lic. just because it can tow that weight ... that does not make any sense. I'll keep looking but I am certain (just looking for it in blaxk and white ) that a standard car lic may not ecxeed the GCM of 4.5 t

[mowog]

I just did the google rounds for the Australian states.

Pretty simple really Car 4.5T max you can then tow a trailer / caravan that is within the towing limits of the tow vehicle.

[Redback]

I just did the google rounds for the Australian states.

Pretty simple really Car 4.5T max you can then tow a trailer / caravan that is within the towing limits of the tow vehicle.

That means that the combined weight is greater than someone holding a LR or even MR licence:eek:

Baz.

[joeT]

And I stand to apologies. Specially to 33chinacars..
On some stuffing around and looking throughout the records I have come across in Road safety ( driver) regulations 2009. Pg 9 and 10
A standard lic. May tow a Single trailer to the max GVM weight of no more then 9t.
Found in black and white lol

Cheers Joe

[mowog]

The Law is full of loop holes is it right? Maybe not but is it legal yes.

My D4 caravan combo is around 6000kg in travelling trim.

[Redback]

And I stand to apologies. Specially to 33chinacars..
On some stuffing around and looking throughout the records I have come across in Road safety ( driver) regulations 2009. Pg 9 and 10
A standard lic. May tow a trailer to the max combined weight of no more then 9t.
Found in black and white lol

Cheers Joe

Where did you find that, I searched everywhere in the RTA NSW and even rang them and they couldn't tell me for certain.

Baz.

[joeT]

I went through vic roads found nothing either. So I googled Road Safety (Drivers) regulations 2009 S.R No. 95/2009. On the bottom of pg 9 continued on page 10. Stumped me

Cheers Joe

[joeT]

Just corrected my thread too. It was NOT. A combine mass it was a single trailer to max weight of 9 t GVM big difference

Cheers Joe

[isuzurover]

That means that the combined weight is greater than someone holding a LR or even MR licence:eek:

Baz.

??? MR is 8 T GVM + and up to 9 T towing.

Well above the c-class limits.

EDIT: The SA website gives examples for what is allowed under a c-class licence as: A small truck towing a horse float...

[Ron Webb]

Hi, I'm in the process of buying a D4 and plan to use it for towing a camper trailer, so this thread is interesting to me. I don't know what a WDH is? From reading various places, it seems a Mitchell Bros High-Rise hitch may be the best.

I previously had a D1 then a Patrol GU, and did plenty of towing with both, with no problems, but I guess the air suspension is a different ball game.

[TerryO]

If you buy D4 you won't need a Weight Distribution Hitch (WDH) as you only need a WDH to transfer weight to the front wheels if your vehicle has old school spring suspension. The D3/4/RRS all have excellent suspension which have made WDH's basically obsolete for late model Disco's.

If your buying a Camper then few to no large 4x4's should need one.

If your planning on towing a large caravan and you drive Toyota or Nissan etc then you may need a WDH.

Also LR say no to using WDH's on air suspended D3/4/RRS's.

Cheers,
Terry

[mowog]

10 Years Later....

I still have the same D4 we still tow with it. She now has 243000 klm on it.

I have however found something that tows our van better. I recently added an L322 TDV8 3.6 and it is a towing beast.