Fitting Spring Assistors

Technical questions and answers about the Mazda Bongo

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apole
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Fitting Spring Assistors

Post by apole » Thu Mar 13, 2008 12:09 pm

Hi,

Does anyone know the gap between the springs on a 2WD bongo.

I need to fit some spring assistors as it bottoms out at the rear when it's loaded up.

Can anyone recommend a good make and supplier?

Many thanks.
Ian
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Post by Ian » Thu Mar 13, 2008 12:46 pm

There is a fact sheet called "Spring Assisters" in members only area which gives full details. :)
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helen&tony
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spring assisters

Post by helen&tony » Thu Mar 13, 2008 12:58 pm

Hi Apole
There is a fact sheet on spring assisters , which,I believe, deals with the air-assist type. I have the type that fits in between the coils of the springs....I fitted mine as a temporary measure ages ago, and have to take them out. The make I have is "Grayston" , and most good caravan shops have them . I would advise against leaving them in, as they more-or-less isolate a portion of the spring from working properly, which will eventually lead to spring failure. They have a small amount of "give" in them, but not enough to protect the spring. Air assist versions can be inflated at will.
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Helen
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Veg_Ian

Post by Veg_Ian » Thu Mar 13, 2008 1:18 pm

I fitted a pair of these a few weeks ago

http://www.towsure.com/product/401-Spri ... _26mm-39mm
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apole
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Post by apole » Thu Mar 13, 2008 2:07 pm

Thanks for your help guys. Just joined properly, about time so I also have the fact sheets which are really useful.

Thanks again.

Andy
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Re: spring assisters

Post by scanner » Thu Mar 13, 2008 2:57 pm

helen&tony wrote:Hi Apole
There is a fact sheet on spring assisters , which,I believe, deals with the air-assist type. I have the type that fits in between the coils of the springs....I fitted mine as a temporary measure ages ago, and have to take them out. The make I have is "Grayston" , and most good caravan shops have them . I would advise against leaving them in, as they more-or-less isolate a portion of the spring from working properly, which will eventually lead to spring failure. They have a small amount of "give" in them, but not enough to protect the spring. Air assist versions can be inflated at will.
Cheers
Helen
That is why it is best to fit them as far to the end of the coils as possible so that only the spring at one end of them flexes. In effect just shortening the spring rather than dedening the middle of the spring.

I also found them too stiff and that can be reduced by carefully drilling a few holes through them, as that makes them far more progressive.
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helen&tony
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spring assisters

Post by helen&tony » Thu Mar 13, 2008 6:01 pm

Hi
Scanner
A member (I forget who) actually posted here that this type caused a spring failure on his vehicle for the reason I stated....It's not my experience, as I have them fitted, and yes, they are stiffer unloaded, but if the spring is , in effect , shortened, then, surely the amount left has to work twice as hard (or equivalent to the portion removed), and the manufacturer carefully estimates the loadings imposed and designs the spring accordingly, or that was what my father always told me, and shortening is not a good idea. If shortening is done to lower a vehicle, it is better to buy a specially made spring, or have your own re-heated and tempered in a shorter configuration.
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Helen
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Post by dandywarhol » Thu Mar 13, 2008 6:12 pm

I fitted a set of the Towsure ones 2 years ago. I've had no adverse effects with them fitted although the rear does still bump out on undulations when laden. I'm just about to fit an air assister kit by Airlift.

The rubber assisters do allow 2 coils to abut and I take your point about transferring the strain to the remaining coils but I'm not sure if it would cause the spring to prematurely fail (unless the rubber channel retains rainwater and causes corrosion)
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helen&tony
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spring assisters

Post by helen&tony » Thu Mar 13, 2008 6:39 pm

Hi Dandy
I hope to get those air assister fitted (with compressor kit), and junk the coil jobbies. Can't say we have had any problems with bottoming out with them fitted, as even with the Bongo loaded to the gunn'ls and towing a caravan, they worked well.
I would, ideally like well lowered springs and hydraulics, but I remember going into this when we had a Type2, and it works out quite expensive, not to say complicated.
Cheers
Helen
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