Spring assisters

[Tonka]

Hi folks, as the rear of the Omega is sitting a little low when hitched up, I am looking for a pair of spring assisters to try and lift it a bit.
The 'van is loaded corrrectly with the correct nose weight. The car is loaded correctly with three passengers and a full tank of fuel. With new springs and shocks.
Yet the van has a distinct effect on the rear of the car.
Have seen them in Towsure and they are around £32 plus delivery. If anybody has a set they would be willing to let me try for a lot less than that I would like to here from you

 

[ProfJohnL]

Hello Tonka

You should never need to use spring assisters.

First check the dimension of your car. When loaded with all luggage and the nose load of the caravan on the tow-ball, the centre of the tow ball should lie between 350 and 420 mm vertically above the road.

If it outside of these limits then one or a combination of three things must be happening.

1. The car may be over loaded - check all you load limits tyre pressures etc (you need to de-rate the boot load if you are towing with some cars
2. The caravans nose weight is too great (you must use the correct method for measuring nose weight)
3. Some part of the cars suspension, tyres or towbar is worn or broken.

The car manufacture will have performed all the necessary calculations and tests to confirm the cars load limits including the degree of suspension compliance when under load. It is never necessary to add suspension assistance to correct a low back end.

People who add assisters only do so for cosmetic appearances. The will affect the cars handling and they do constitue a modification which must be reported to your insureres.

 

[Lutz]

I would just like to add that the back end of the car cannot sit any lower when the caravan is hitched up than if it were solo and fully laden. Therefore, if you have a problem when hitched up, you would also have a problem solo but with the boot full.

 

[Gafferbill]

……..I have used this Towsure product fitted to a Rover Montego a few years back.
They were fitted for 6 years of towing with no problems.
You will effectively be increasing the rear spring rating for your car’s suspension and this will give a hasher ride when solo and lightly laden.
Laden or when towing the effect will be to raise the rear of your car which is why they are sold as a towing accessory which benefits some cars.

 

[xtrailman]

I have used the rubber doe-nuts to good effect in the past, on four different cars, they can be left in position permanently.

 

[Tonka]

Thanks for the replies guys. All very informative and I think I will try a pair. I will hold back on buying any new in case anybody has some in their garage they can let me have at a reasonable cost

 

[Dustydog]

Tonka
See this . http://www.practicalcaravan.com/review/accessories/grayston-rubber-coil-spring-assister#
Our Nigel D fitted a pair and toured Croatia with them.

 

[ProfJohnL]

Spring assisters do not cure over loading, they do not increase the load capacity of your car so before you decide to fit them do make sure you are not actually overloaded.

 

[ProfAlGoogle]

Can't see any problems with fitting assisters, used to have a set on my Volvo 740 many years ago (Monroe load levellers) used to pump them up with an on board compressor, and also bear in mind that a lot of manufacturers offer self levelling suspension as an option, normally advised if you intend to carry heavy loads, had them fitted on my first V70 and found them to be a great bit of kit.

 

[Tonka]

Thanks for all of your suggestions and advice folks

I have been offered a set of Monroe adjustable air shockers so I will have the best of both worlds, fantastic

 

[ChrisUK]

Can't see any problems with fitting assisters, used to have a set on my Volvo 740 many years ago (Monroe load levellers) used to pump them up with an on board compressor, and also bear in mind that a lot of manufacturers offer self levelling suspension as an option, normally advised if you intend to carry heavy loads, had them fitted on my first V70 and found them to be a great bit of kit.

good point. what is the difference between self leveling suspension and spring assistors like MAD springs.
However when I wanted to fit them to my previous car (Mazda 6) my insurers (Zurich) said NO.

 

[Lutz]

what is the difference between self leveling suspension and spring assistors like MAD springs.

The difference is that a self levelling suspension increases the spring rate only when payload is applied whereas a spring assistor raises the spring rate all the time, regardless. In most cases, the self levelling suspension adjusts the front suspension at the same time, in order to maintain a correct balance between the front and rear.
The reason why an insurance company may object to fitting spring assistors at the back only is that by doing so, this makes the car tend to oversteer and this could be critical in an extreme situation.

 

[xtrailman]

Spring assisters do not cure over loading, they do not increase the load capacity of your car so before you decide to fit them do make sure you are not actually overloaded.

But they do stop the back of the car dropping as much.
With out them my hatchbacks would drop one and a half inches.

 

[ProfJohnL]

Hello Ray,
I'm pretty sure we have discussed this before, but for any other readers:-

Except wher you have OEM self leveling suspension fitted , it is inevitable that when you apply any load to the rear of a car the ride height will change . That is a situation that all car manufactures have to allow for when designing. Their specifications are goverened by EU regulations, and that allows for a loaded towball height of 350 to 420mm (Measured vertically from horizontal ground surface to the centre of the tow ball). These limits give a potential range of 70mm or 2.75".
The regulations mean that for any trailer within the towing capacity of the car, the minimum and maximxum nose (and boot and car) loads must not cause the tow ball to exceed the height regulation range.
You note a 1.5" (38mm) drop when you attach your trailer, What you dont tell us is if that causes your tow ball to drop below the lower regulations limit of 350mm. If the tow ball remains within the regulations range then there is nothing to worry about, the car is within specifications. However, if the loaded ball drops below the lower limit, then something is amis, and it should not be ignored.

There are sveral single possibilities or it may be a combinatins of two or more of the following:-
- Either the cars suspension is overload (Possibly from a combinations of trailer nose load and or the content of the car and its boot) - Or there is damage or component wear in the suspension,
- Or the tyres are under inflated.
- Ultimately if everything else above checks out, then that only leaves the car its self, and if it fails to comply than that is a matter you should take up with your supplier.

If the tow ball sinks below the lower limit then something is wrong, and the use of after market spring assisters will not correct the failure and may actually mask a more serious problem.

If the the tow ball is still within limits, then there is no technical reason to want to change it. Consequently if and you still want to raise its ride, then it is your choice dictated by apperance rather than need. It certainly consitutes a modification to the vehicle and may invalidate warranties and guarantees. and it must be reported to your insureres.

 

[Lutz]

With out them my hatchbacks would drop one and a half inches.

My simple and straightforward reply to this statement is 'so what?'. So long as the suspension doesn't bottom out and the towball height remains within the specified limits, why should one and a half inches be a problem?

 

[xtrailman]

http://www.practicalcaravan.com/review/accessories/grayston-rubber-coil-spring-assister

I can recommend these.

 

[xtrailman]

I can recommend these.
http://www.practicalcaravan.com/review/accessories/grayston-rubber-coil-spring-assister

 

[xtrailman]

With out them my hatchbacks would drop one and a half inches.

My simple and straightforward reply to this statement is 'so what?'. So long as the suspension doesn't bottom out and the towball height remains within the specified limits, why should one and a half inches be a problem?

http://www.practicalcaravan.com/review/accessories/grayston-rubber-coil-spring-assister

 

[xtrailman]

With out them my hatchbacks would drop one and a half inches.

My simple and straightforward reply to this statement is 'so what?'. So long as the suspension doesn't bottom out and the towball height remains within the specified limits, why should one and a half inches be a problem?

It brings a already low jockey wheel, even lower.

Thats what.

 

[ProfJohnL]

Hello Ray,

I seems to me that provided the tow ball remains within the EU window (350 to 420mm) , if the jockey wheel is then so low that it catches the ground, then the problem dosen't lie with the car but the caravan.

Fitting spring assisters to overcome that is not curing the problem its masking it, The proper solution is to find out why the jockey wheel does not retract far enough.

Don't forget that all the caravan manufactures know of the EU tow ball height regulation and should be manufacturing their products to work fully satisfactorily anywhere within the stated range.

 

[Lutz]

Besides, fitting rubber coil assisters, of the type described in the PC review, reduces the amount of available spring travel, so you're more likely to bottom the suspension out. This is a risk which would be avoided in the case of a self-levelling suspension.

 

[xtrailman]

http://www.practicalcaravan.com/review/accessories/grayston-rubber-coil-spring-assister
Reader reviews
Ditto

 

[Gazza1]

Hi Tonka,

Little late in my reply, but I have a set of MAD auxiliary spring assistors, I used them on my Omega for a couple o years. Vastly improved the ride height whilst hitched up, especially on the Omega it has a massive overhang (the boot). Let me know if your still in the market?
Cheers Gazza
tin.shedder@ntlworld.com

 

[Tonka]

Hi Gazza,
I reported earlier that I had some Monroe adjustable shocks coming but the guy welched on the deal. Fortunately I hadn't paid him. You need to be so careful........

I have now got myself some MAD auxiliary spring assisters. They are fabulous and keep the ride much more level and reduce the wallowing to a minimum. Thanks for your kind offer mate.

Cheers, Sean