Suspension stiffeners

Fitted them to our Volvo S80 as previously there was a lot of sag as soon as we hitched up and the ride was very bouncy.

Straightforward to fit and cured both the sagging and the bouncy ride. 

Years ago when I had a caravan I fitted MAD Springs to a Peugeot 405 and they made a big difference. It could have been my imagination but I seem to recall that the rear of the car was slightly higher when solo but it didn't seem to have any impact on roadholding. 

David

We fitted MAD springs to our Fourtrack which was fitted with all round coil springs and was great when solo ,but Quite soft and bouncy with most trailers and caravans , they were easy to fit and made the ride much firmer and stopped the bounce and did not seem to affect the ride  when not towing

The back of the car shouldn't sag any more with the caravan hitched than if the boot was fully laden. The manufacturer has specified a maximum allowable rear axle load which should take care of a fully laden boot or the noseweight of the caravan, so if the back end sags more than it should either the boot is overloaded or the springs are showing signs of old age.

Thanks for your comments. I'm going to try with the suspension stiffeners. If they don't work too well I'll look at the MAD springs.

The car is 2 years old but the caravan noseweight is well back from the rear wheels which effectively increases  the loading.

I can put three bags of cement in the back with no problem- its a citreon berlingo - but 60k on the towball is another matter.

Unless the car has an abnormally large rear overhang from back axle to towball that statement is a bit illogical. I wouldn't call the rear overhang of a Berlingo particularly large.

Three bags of cement weigh 75kg which is less than 60kg on the towball, so how can the back end of the car sag more with just 60kg on the towball, but not with 75kg in the boot?

Perhaps he carries the cement to make a hardstanding when he arrives with his caravan. 

Lutz, I take your point on the car should not sag if loaded within limits, but why then do manufactures offer self levelling rear suspension to cope with this very situation.

Colin

Of course the rear end will sag if a load is applied. That's just plain physics, but the manufacturer has documented that the degree of the sag will still be acceptable when the car is loaded to its rear axle load limit. In other words, there will still be enough suspension travel to cope with road conditions.

Thanks for all comments.I bought Grayston spring assisters on line - £39 a pair inc postage..I had the spring assisters fitted at our local garage. Tom , the owner, said they were a pig to do, he had to drop the springs and was most apologetic about charging me £70.

I have just returned from a trip , 260 miles return. The assisters were excellent. When fitted they raised the car rear by 1.5 cm. With the van on and a nose weight of 70k approx there was a drop of 1.5 cm ! Before the assisters the car would had sagged badly.

The ride was good , a bit more bumpy but hardly noticeable, handling , braking was normal.Solo handing, ride the same as towing.

Mileage -we were on the M6 and A50 so no real hills - was 34m to the gallon at 2000 revs.

The van is right at the limit of the car's tow weight so I am pleased with the assisters and would heartily recommend them.