Caravan Towing.
This information is for Caravans only. Towing a boat irrespective of its size, is totally different.
A weight of a boat is usually spread directly over the axles on the boat trailer and the draw bar is a lot longer than a caravan. Boats are more stable and rarely ever require a weight distribution hitch.
Towing with a Caravan can be a drama if the weight is not evenly balanced. To much weight to the rear and your rig will be very unstable and start to sway. If the van is heavy enough, the swaying will up end the tow vehicle and caravan. If the weight is too heavy at the front, it will take the stable weight off the front wheels, reducing you steering ability, sending you off the road or straight into on coming traffic.
Weight and balance is a bit like a seesaw.
The problem arises from point where the towed device attaches to the “Tug”.
In the case of this tractor and trailer, the tow bar is right at the driving wheels of the tractor, which is ideal for both tractor and trailer
This also applies to Prime movers, where the turntable is directly above the rear wheels, which is the most stable position for towing a trailer.
No doubt you have seen 5th wheelers, they are also one of the safest towed trailers on the road, due to the position of the turntable.
As you can see, the weight is directly over the rear driving wheels, giving maximum grip for the tug and will it not interfere with the balance on the steering.
The seesaw motion starts as soon as the tow ball is moved back from the rear driving wheels and the further the tow bar is from the rear wheels, the worse it gets.
Here is a Land Rover with large 2 tonne caravan.
Although it is hard to see it, the Land Rover has a Hayman Reese Weight Distribution Hitch fitted, similar to this one.
Towing a caravan, horse float or very heavy trailer can apply a heavy additional weight on the rear of your vehicle which is referred to as the ball weight.
The weight will be carried by the rear wheels which will raise the front of the vehicle, thereby reducing the weight on the front wheels.
As a result the vehicle will experience a reduction in steering and braking control.
The Weight Distributing Hitch is designed to ensure a return to even distribution of weight across all wheels of the tow vehicle and trailer.
This even distribution of weight ensures that positive steering and braking control is maintained.
In a way it's a bit like have a big tension spring between the tow vehicle and caravan but can be thought of more easily if the weight distributing bars are compared to handles on a wheelbarrow. The higher the handles are lifted the more weight is moved onto the wheelbarrow wheel and the easier it becomes to hold it up. Similarly, the more tension that is placed on the weight distribution bars, the more weight is transferred forward onto the front wheels of the tow vehicle.
There are various makes on the market to suit different weight applications.
Suspension
Generally the type of suspension on the towing vehicle is not important as long as it is firm. Leaf springs are often considered more capable of supporting loads than coil springs but a good load distribution hitch will counteract the tendency of the rear of the vehicle to sag. As long as the suspension system (including the shock absorbers) is in good condition, then suspension system modifications for towing a caravan are not usually necessary, unless specified by the vehicle manufacturer.
Self-levelling Suspension
Some vehicles are fitted with self-levelling suspension. If this is the case, then the manufacturer's recommendations in regard to hitching up a trailer must be followed. Unless the trailer is very small, a load distribution hitch is almost essential on these vehicles and failure to follow the recommendations could result in damage to the vehicle's suspension.
I Realise Land Rover have stated, DO NOT use a WDH with a self-levelling suspension.
This is from a Road Test with a Discovery 3, air suspension:
“Evident within the first few kilometres was a quiet, cushion-soft ride and steering that offers the usually conflicting qualities of light control and plenty of feel. Unfortunately, also evident was a nervous gait that had me dropping the nose of the van just six kays up the road. With the hitch dropped two holes, it still wagged during another dozen kilometres of freeway; I lifted the chains one link each side.
Whoa, it made a hell of a difference. No more wiggle. It seems the Disco - due, no doubt, to its auto-levelling suspension - is very sensitive to ride height and load-distributing chain tension. Sorted, 100kph cruising was a doddle and it was difficult not to creep up to 110 where the Disco diesel, in fact, felt happier.”
If in doubt over vehicles with air or Hydraulic suspension, play it safe and use a different, sprung, vehicle.
RoverLord
The last comment is interesting - perhaps the best handling towing vehicle I have used is my DS Citroen - self levelling suspension, but with the tow bar at the rear wheels, and zero sideways elasticity in the suspension (instead of bushes it has tapered roller bearings), plus a very long wheelbase. And the handling was independent of tow ball load (although I never tried it with upward load!).
John
John
JDNSW
1986 110 County 3.9 diesel
1970 2a 109 2.25 petrol
Originally Posted by JDNSW
Hi John,
I did tow a few trailers and a boat with my Citroen
and all was well. The rear wheels are so close to the rear of the vehicle, which is good for balance
The front certainly never lifted, but I had blown spheres through over loading.
The air sprung rears on some of the XJ40 Jaguar were a total disaster. I doubt there is one left with air suspension.
Most owners ripped it out and put coils and shockies back in.
You may find this article interesting.
A Landrover with DS suspension
It appears to be a SII Land Rover, fitted with Citroen suspension, with Nissan engine and bits of Jaguar!
Cheers,
Ron
After towing huge vans with the F350 4wd for 2 years I have found the WDH's to be only helpfull on vehicals that have a low ball weight but of very little use with vehicals which are of a matched weight or heavier than the towed load.
On vehicals that are heavier than the load that is being towed and suspention that is stiff enough to hold the said load up, the only advantage is the anti sway caracteristics if the torsion bars are strong enough.
A WDH ONLY reduces the ball weight by way of spring pressure between the draw bar and the tow bar, the added advantage is the anti sway capability it gives due to extra spring pressure on the draw bar.
I would recomend them to anyone who is going to be towing a large load but with caravans, as long as you load them properly and they are built to be balanced properly then you shouldnt have any problems.
By far the safest way to tow a very big van is to have a 5th wheeler of goose neck and the suspention rated to suit the turn table or ball load or fit airbags.
If you are going to use a WDH on a Land Rover you must change the towbar to one that will take a WDH (as i have been told) the LR bar is not designed to take the up force that the WDH puts on it.
Last weekend i heard (so far unconfirmed) that people running a WDH on the D3's have had the locking pin snap off (the one that holds the tow tounge and ball on)
I and members on our Caravan Forum have seen some very odd and dangerous setups, recently.
One was a "Know it all" with a old Toyota LC Ute, large van on behind, no WDH, with the front of the vehicle stitting up in the air, bum down and draw bar almost on the road.
When asked why he did not put on a WDH, "Don't need crap like that, this is a 4WD!" He is still out there, waiting to cause an accident. First slippery corner and he'll be off the road in the bushes. I just hope no one is coming the other way. Trucks and tractors are about the only thing that don't require a WDH.
Last Caravaning weekend we went to, there was a guy with a medium sized van, being towed behind a late 60's early 70's 280/300SE, 6.3 V8. It had the horrid MB airbag rear end, and it was leaking. He had to start the car, hook up the van and then fit the WDH. Even then, it still sagged at the rear. The moment he turned the motor off, the old Merc sat on the ground.
I have seen a Jap FWD car towing a van without WDH. The front of the car was up so far, I was surprised he even got traction to drive the thing!
Some times, I think people should have to get a special license to tow anything larger than a 7x4 trailer. The stupidity of some people and total ignorance of equipment required in towing Caravans really worries me. No small wonder there are so many accidents.
Any normal passenger car, ute or 4WD should have a WDH. IF the caravan is very small and light on the drawbar, it may not be needed. However an anti sway bar would be an advantage. Passing a large vehicle may cause the van to sway from air pressure.
An other thing to keep in mind. When a Semi or large truck is about to overtake you and your van, lift your foot off the accelerator a little as the truck pulls out to pass, then slowly increase speed as the truck goes past. This will stop the van being sucked into the side of the truck as it goes past. Once the truck has cleared the front of your vehicle flick your headlights to let him know he is past you. They do appreciate it
Gday Ron, we have SLS and i will not use the WDH, i have used it and have found our car drives and feals better to drive on the road without, Last weekend we went to Bunya MTS with the Kedron Owners Group, when we hitched up to come home a few of the Toymota owners came over to have a look when we hitched i closed the doors and up she went to ride height and the car and van where both level, then we drove out with them all looking and talking. All we need in the car now is the TDV8 to pull a bit better
Hi MarknDeb,Gday Ron, we have SLS and i will not use the WDH, i have used it and have found our car drives and feals better to drive on the road without, Last weekend we went to Bunya MTS with the Kedron Owners Group, when we hitched up to come home a few of the Toymota owners came over to have a look when we hitched i closed the doors and up she went to ride height and the car and van where both level, then we drove out with them all looking and talking. All we need in the car now is the TDV8 to pull a bit better
It's a pity there is no pressure gauge telling you what is being forced into the rear suspension.
What ball weight is your van?
Cheers,
Swaggie
Centre point of a turntable of a real semi-trailer rig is usually about 300mm ahead of the centre line of the rear axles, not on centre as in the photo above. On or behind centre pin gives noticeably worse ride and handing. Try it some time.
URSUSMAJOR
Brian,
You may get a smile out of this.
There is one born every minute
Cheers
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