I have seen many cars towing caravans with sagging rear suspension, the tow bar height is therefore lower than it should be.
When a caravan is towed, the weight of the van lowers the suspension even more and so the tow bar is even lower - hence more weight is applied to the tow bar.
I am thinking of a caravan next year.
The suspensionon on my Volvo 940 estate, when unloded, is a good 2 inches lower at the rear than it is at the front.
Will this be a problem when towing a caravan {70 kgs down force}, should I up rate the suspension, can I fit stiffer / longer rear shocks / springs.
Should the rear suspension, not be a good 2 inches higher on the rear, than the front, on an unloaded tow car, so that the suspension is level front and rear with the caravan fitted.
Any suggestions please
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Paul,
Suspension designers dilemma here. Set the car up for a single driver and have it on th ground at the back with the van on for the hols.......or stiffen the rear up so it rides like a board when unladen. Or have a middle setting so it's wrong at both extremes???
You know where this is going don't you......the Citroen self levelling system. No joking it increases the towing ability/comfort no end to have a system that resets the ride height regardless of load.
But I don't think all is lost with the Volvo. I've mentioned before a 1981 Saab 99 Turbo I used to own, well I fitted this with a Saab approved aux air spring system for towing a large boat trailer.
This needed the rear springs to be removed and heavy duty air tubes (rubber) fitted inside them before re-fitting. Each tube was connected to a hose that went to one valve mounted in a suitable place. On mine this was just behind the drivers seat in the floor.
Normally these tubes had about 4psi, just to give a positive pressure, and didn't change an unladen car. When about to tow you used a normal air line/pump to raise the pressure to about 15psi (The de-luxe kit had a compressor with dashboard control). This meant the final ride height with a full load was the same as unladen. What a difference.
I understand this same system, made by Firestone, is still available. Try TrailerTek Nr Winchester on 01962 774988 or e-mail sales@trailertek.com I'm looking at their ad and the "Coil-Rite" system is nearest to the Saab system. There are also two other variants for alternative suspension setups.
Hope this helps,
David
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I towed a caravan with a 740 TD estate from 1989 till 1997 including long continental trips with wife and two sons. During all that time the suspension was never modified and never caused any problems.
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There not bad to tow with,Think of asize of caravan you want and then go a little smaller this will make up for "we will just take that and that syndrome".I tow with a xm2.5td with a 6 meter caravan 1500kg unlaiden and as Dave said they are the ultimate towing car.(please note I said car and not vehicle)I am a confirmed caravanner and we have friendly enemies in the back room but I use my caravan for work ,no matter where I am in Europe the caravan is my home and my office.From next week I shall be in Essen for six months or so all through the winter except for a trip down to Spain at Christmas time
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I don't have the figures to hand, but I am fairly sure that 70 kg noseweight is a little too high. My feeling would be more in the line of 40 kg but I am sure someone here or a 'van shop will have chapter and verse for car models, 'van makes and towing conditions.
Some vans are badly balanced, on ours I have to load it with the spare cylinders at the rear to keep the noseweight down. (Moving the wheels is not an option!)
If the jockey wheel is too low when hitched to the car you can get a height adjuster plate from Halfords or a caravan dealer to lift (or lower) the height of the ballhitch.
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Paul
I've been caravaning for about 15 years now and have never had a problem with noseweight and sagging suspension, provided the outfit is loaded and balanced properly. 70Kg noseweight sounds about right for a modern van (my Swift Challenger 470SE is given as 75Kg max). This is about 1.5 cwt. I even towed this van with a Citroen ZX TD estate last year. It was really on the limit for maximum weight, but the noseweight and alignment was not a problem.
Your Volvo 940 estate will take a fair old load in the boot. Admittedly 75Kg on the towball is probably equivalent to double that amount when calculated as a load at the centre of the boot load space, because you have a fair overhang. Even so, 150Kg (3cwt) is not an unreasonable boot load for a vehicle like yours.
You will need to be very careful and rigourous about what you put in the outfit, and where you put it. If you are going equipped for a family of 4 and have lots of gear in the boot and/or bike racks on the back of the car then air assisted springs, such as David W describes would be a good investment.
When you have the outfit loaded and hitched ready for towing it is good peace of mind to open the boot and sit on the edge of the boot floor, by the bumper (2 people if you are light in weight) to get some idea of how much compression there is in the Volvo rear suspension. If you are unhappy with how much there is in hand, then fit air spring assisters. You can also judge whether you need a plate to adjust the height of the towball so that the outfit is level.
Most outfits that are seriously out of level are poorly loaded, and usually over loaded. I hope this helps.
Ian
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Wow! a cravan thread and no sign of abuse from HJ.
I have had the same caravan for 12 years and towed it with 3 Citroen CXs, a Citroen XM and a Volvo 760 estate. Without doubt the 760 was the worst towcar of the lot, even though a more recent design than the CX. If you look underneath ( I am not a qualified motor engineer), the Citroens have rigid trailing arms swinging on massive roller bearings supporting the rear wheels. The Volvo had a live rear axle, coil springs and feeble-looking rubber bushes.
Despite the publicity and owner's testimonials, I doubt whether the Volvo was designed to tow anything bigger than a trailer-tent. My caravan has 75 Kg (give or take) weight at the hitch.
If you *must* tow with a Volvo, check out the air suspension reinforcement as described by David Woollard, and don't forget to check your headlamp alignment.
Seeing some of the junk staggering up and down the A1 with bits falling off and the rear suspension on its bump-stops makes me despair of the caravanning community. And mirrors (while I'm on my soap-box); door mirrors are not sufficient; decent extending mirrors should be mandatory.
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Been caravanning for nearly 20 years but seemingly can't spell caravan.
D'oh
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I have nothing against caravans and their owners, but they do have a habit of holding up a queue of traffic behind them on winding A & B roads, which make us 'locals' late for work. If they could pull in at intervals and let the local (faster) traffic pass, it would be no problem!
Ask Guy, he works in Watchet, just off the busy A358 towards Minehead - that route is a real nightmare in the summer months!
Rgds
David
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I like caravanners a lot of them are sensible enough to drive large vehicles that can actually tow there caravans safely and a few of them have realised that diesel power is not great. so to these I say thankyou keep gassing your cars holding up the locals and paying my wages
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Some of us do, David.
Not all dogs bark
Not all cats mess in your garden
Not all drunk people are objectionable
Not all teenagers are a pain the the butt
Not all caravanners are unreasonable
I share your frustration, though.
Ian
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Thanks Ian! Well done - it just shows common courtesy.
Just a shame others don't seem to follow your example.....
David
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