PS. A twin axle caravan (I assume this is one) whould be pretty stable.
The towball, when measured from ground to ball centre should be between 350 and 420 mm (vehicle fully laden, but without caravan attached). It can be high on some 4x4s, leading to the caravan towing nose up, so the air pressure from under the car keeps trying to lift the front of the caravan.
Edited by Marlot on 08/02/2010 at 10:12
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Checked all the specs changed the towball also to suit new Alco hitchlock. I had the leaf springs changed on the jeep 2yrs ago the effect of this were a bouncier ride without the caravan attached but this shoould not really be a problem when going straight. I allways check the caravan when hitched up and there is normally next to no weight inside when towing.
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You need to adjust the tow hitch height so that the caravan is level, with each set of wheels loaded equally on the ground.
Then you need to add weight to the front of caravan so that it has the right nose weight.
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Thanks Cliff, will check towball height again think it could be more 450 centre from ground when jeep not loaded. Also with no weight at front of caravan may be causing some problems.
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Do you have a stabiliser? If not that could help as well.
Edited by b308 on 08/02/2010 at 14:02
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The Alko system is a stabiliser, of course, but I find it beneficial to use my Scott TrakR blade type stabiliser as well....it keeps the whole outfit very stable.
Ted
Edited by 1400ted on 08/02/2010 at 17:19
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>>Thanks, picked caravan up from new on Friday so van was empty.
Insufficient nose weight is the first thought, as others have said. Your comment that the van was new and empty is a clue! Two gas cylinders in the front locker may well do the trick.
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Agree about nose weight, also OP mentioned new rear springs causing bouncy ride yes could be stiffer ride but 'bouncy' has me wondering about rear shocker condition, worn shocks won't help.
Agree with Ted about a good old fashioned blade type stabilser (simple and effective), and with other comments about towball height...especially important towing a twin wheeled trailer.
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No mention of what the noseweight actually is - if the ball is too high, it would have the effect of reducing the noseweight on a single axle but raising it on a twin. Excessive noseweight could well make the car wallow.
As suggested I think you need to make sure the caravan is towing level and that the noseweight is within limits, preferably at or just below the lower of the hitch limit and the car's maximum nosweight. It's not always the case that unladen caravans have low noseweight - depending on the interior layout, some models are nose heavy out of the factory, and would be in any case if the ball is so high as to unload the front axle of the caravan.
Car tyre pressures are likely to be implicated unless they are at the high load pressures - lateral stability at the rear end of the car is critical and the high profile tyres on the Jeep will not work well if underinflated. Any excessive wear in the rear suspension will make matters worse.
Although it has a high towing limit, the Cherokee is not a heavy car - about the same kerbweight as a CRV, which I would not attempt to tow a heavy twin axle with even if it didn't exceed the towing limit. I assume the Jeep has a low box which will account for the high weight limit, but caravans are a different kettle of fish to a heavy flat trailer, and an eight metre caravan is just a big sail in windy conditions and when passing, or being overtaken by, large vehicles.
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No disrespect to the original poster but it strikes me you may be a new caravanner and that you haven't been very well advised by whoever sold you the new caravan (presumably a dealer)
I agree with Manatee the kerbweight of your jeep vs your heavy twin axle bailey is an issue regardless of what the max towing weight of the vehicle is. Noseweight and so on all need checking and tweeking depending on what your noseweight is on the jeep. Some vans need more weight to the front to increase the noseweight from empty, but actually these days its very difficult to get down to the max noseweight for your vehicle on may vans, even with just two gas cylinders in the front you may exceed it.
I found a tremendous difference to the stability towing my single axle van with just a little moving things around to get the noseweight down from 100kg (previous owner had an Isuzu troooper) to 75kg to suit my Octavia.
Good luck...I suggest you hook up to the camping and caravanning club or caravanning club website and try their FAQs
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I believe I have read somewhere that there may also be manufacturers' prohibitions on pulling certain twin-axle caravans with traditional 4X4 vehicles with stiff springs.
The point I think is that caravan chassis are quite lightly constructed, and need a towing vehicle with a high spring movement in order to keep all 4 wheels on the ground and so not straining the chassis.
Also with stiff springs on the towing vehicle the loading on the caravan wheels will switch suddenly from front pair to rear pair according to whether the road surface is concave or convex, with corresponding changes in handling characteristics.
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Thanks everyone for taking time to respond. Think their is a fair bit to digest Jeep has mot this week so will get the machanic to take a good look at shocks and suspension and so on. As for nose weights think there is a fair few differences in what is correct or not. I have been towing for 7yrs now with various cars and caravans and have always tried to keep the van straight on the tow ball. I did experience this problem with my last van Bailey Pageant sing axle when towing with the jeep. Never experienced any trouble with other cars prior to the Jeep. Maybe the Jeep is the problem not the loading of the caravan.
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