# Shock Absorbers



## piggiebank (Jun 12, 2014)

Hi. I have a hobby 650 a fiat ducato with an Alco chassis. One of the shock absorbers has snapped and is hanging loose would appear to have been there a while. I am aware i need to replace both. I beleive blue ones are about 100 gbp each. I did a general search hence my question. A post i saw on another site mentioned a weight limit of 2300 kg for blue ones and black ones for a higher limit. The ones fitted currently are blue. Is this 2300 kg per axle or gross weight. My gross weight is 3490 kg. Has my MH been fitted previously with the wrong ones

Cheers 
Graham


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## lgbzone (Oct 8, 2008)

Hi Graham
Although I can't say for definite; I would assume/guess that 2300 is referring to the maximum load of the rear axle. the reason being that 2300 is a common limit for the Alko rear torsion axle (our Hymer B644 is 2300) and i've never heard of a motorhome with a gross weight limit of 2300 on an Alko chassis. Furthermore, how strong the axle is sprung is related to the weight the axle can carry, and how strong the axle is damped is related to how it is sprung.
Hope this helps
Lee


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## piggiebank (Jun 12, 2014)

Thanks Lee. Do i inderstand corectly then that i am okay to use the blue shocks?


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## bognormike (May 10, 2005)

when I had problems with shock absorbers on my old Pilote with an Alko chassis, the shocks were only available from Alko. we had terrible problems getting hold of them, and of course they were twice as much as "standard" off the shelf shocks. where are you getting them from , and are they the genuine replacements? As you say, has somebody else fitted the cheaper alternative before?


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## erneboy (Feb 8, 2007)

I fitted a pair like these to our Autotrail Mohican a few years ago. Since then I recommended them to someone else and a poster on here told me that they are for caravans only. I don't know if that's true (doubt it) but they did fit perfectly well and did the job. http://www.ebay.co.uk/itm/AL-KO-SHOCK-ABSORBERS-KIT-BLUE-X-2-/371325933599?hash=item5674c0181f


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## Mrplodd (Mar 4, 2008)

Not an item to take chances with. They are NOT "shock absorbers" they are "dampers" and their purpose in life is to damp out the oscillation of the road springs. Think of your rear axle on a bumpy road being like a very bouncy "super ball" (remember them?) the damper is there to STOP the bouncing after just one and a half oscillation. 

They are required to absorb a lot of energy and fitting the wrong ones could have a serious detrimental effect on your vehicles handling.

PLEASE ensure you fit the ones specified by the vehicle manufacturer, they will have spent a lot of time and effort making sure the original fit items do EVERYTHING required of them. 

Andy


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## deefordog (Dec 31, 2013)

If the blue ones do the job, then the caravan ones might be OK http://www.al-ko.com/shop/uk_vt/products/caravan-accessories-1/shock-absorbers.html. But are these the same for MH's. But for some reason, AL-KO don't list MH specific ones in their on-line shop.


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## erneboy (Feb 8, 2007)

Mrplodd said:


> Not an item to take chances with. They are NOT "shock absorbers" they are "dampers" and their purpose in life is to damp out the oscillation of the road springs. Think of your rear axle on a bumpy road being like a very bouncy "super ball" (remember them?) the damper is there to STOP the bouncing after just one and a half oscillation.
> 
> They are required to absorb a lot of energy and fitting the wrong ones could have a serious detrimental effect on your vehicles handling.
> 
> ...


If you need to split hairs to that extent Andy perhaps you'll tell us what you define as "road springs."

Then you can explain why you think people should fit only parts specified by vehicle manufacturers. Perhaps you haven't noticed but there's a huge market out there selling parts which aren't recommended or specified by the vehicle manufacturers but which are well know to do whatever job as well or better that the standard items and often these parts cost a lot less.


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## Pudsey_Bear (Sep 25, 2008)

piggiebank said:


> Thanks Lee. Do i inderstand corectly then that i am okay to use the blue shocks?


I'd be very wary of renewing based on the colour of the old ones, they may have been incorrect in the first place and why they've failed, I'd be getting advice from a company who specialises in springs and or dampers, some suppliers ask for the VIN to get the right parts.

*Shock absorbers*


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## deefordog (Dec 31, 2013)

I'm sure a call to AL-KO would be productive?


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## erneboy (Feb 8, 2007)

By all means replace by colour if you're using Ak-Ko, they are colour coded purposely. Just check that the colour you are considering satisfies the weight range you need. http://www.al-ko.co.uk/pages/shock-absorbers-3.html

Ploddy, Al-Ko think they are supplying shock absorbers, maybe they need correcting.


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## lgbzone (Oct 8, 2008)

piggiebank said:


> Thanks Lee. Do i inderstand corectly then that i am okay to use the blue shocks?


Hi Graham
not necessarily, i'm stating that if the blue shocks (dampers) have a limit of 2300kg then i'd assume that's axle weight not vehicle weight (your original question), and that's based on the fact that the damper is tuned to the spring, and the spring is tuned to the axle weight, and 2300kg is a common alko axle weight.

you should have an alko plate on the van, mines under the bonnet showing chassis type and rear axle weight etc, this info may help. the fiat vin won't as it doesn't refer to the alko part, you could end up with fiat dampers. i agree with deefordog, it could be worth contacting alko.

i've attached alko manuals for 244 and 250 chassis, they have info and contact details in them.

while you are at it; get the rear axle unloaded and grease the torsion springs.

Lee



Mrplodd said:


> PLEASE ensure you fit the ones specified by the vehicle manufacturer, they will have spent a lot of time and effort making sure the original fit items do EVERYTHING required of them.
> Andy


Like the fiat 5th gear issues that spans 10 years of production, what about the fact that our hymer A class, and many others, that (in OEM spec) travel around with the front shocks practically resting on the bump stops, obviously under sprung and you don't need to be a mechanic to determine that. fitting third party springs vastly improved both comfort and handling.

Lee


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## Mrplodd (Mar 4, 2008)

Road springs is an accepted term for any form of resilient material used in motor vehicle suspension, be it a metal coil or leaf spring, a torsion bar or even a block of rubber. It is a generic term for any type of spring fitted to a road vehicle, hence "road spring" 

If you read my post I have NOT said the OP should fit dampers made or supplied by the manufacturer, only that they should meet the SPECIFICATION of the manufacturer. As I said they will have spent a lot of time and effort ensuring that a particular item of a particular specification will do the job that is required of it. 

As someone who spent several years in the motor vehicle repair industry (a long time ago) I am of course well aware that a large number of companies produce all sorts of components for vehicles. I am also well aware that Fiat, Alko, Citroen, Ford, Nissan, Mazda, Seat VW and just about every other vehicle manufacturer do NOT produce items such as brakes, dampers, clutch's etc etc themselves. They buy them in from specialist manufacturers HOWEVER they provide these specialist firms with detailed specifications to ensure that the parts provided are up to the job. Either that OR they design their vehicles to use items already on the market. 

What I have said is that the OP needs to be sure that any safety critical part (in this case dampers but the same goes for brakes etc) should at least equal the original spec!!! If you think of a reasonable sized motorhome travelling on a bumpy road the bodywork will remain fairly stable due to its mass having a high rate of inertia, the suspension will attempt to absorb the movement of the road wheels moving up and down in respect of the road, therefore the damper is required to dampen this movement out in one and a half oscillations, if it doesn't there is a chance that the wheel itself will bounce up and down and in doing so lose contact with the road surface, a process called "pattering" if the wheel is pattering it cannot supply any grip because it's not in constant contact with the road and that's not good on bends or when braking! If a replacement damper is not capable of absorbing that energy then the results could be serious. Hence my exhortation to ensure the correct spec items are fitted.

Andy


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## erneboy (Feb 8, 2007)

Mrplodd said:


> PLEASE ensure you fit the ones specified by the vehicle manufacturer, they will have spent a lot of time and effort making sure the original fit items do EVERYTHING required of them.
> 
> Andy


I see. Have you ever know a vehicle manufacturer to specify anything other than OE Ploddy?


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## Mrplodd (Mar 4, 2008)

Erneboy

Nope, because original equipment is exactly that, original equipment.

On a simplistic level think of a vehicles fuse. The OE is a certain amperage with a SPECIFIED time for it to fail if overloaded because if it takes to long the bit of kit it's protecting might get damaged. You could easily buy another cheaper Chinese make, none OE fuse of the same amperage rating BUT it might, because it's made of cheaper materials, take LONGER to "blow".

Both will do the job but the cheaper one, by not failing fast enough MIGHT cause damage to the bit of equipment it has been installed to protect. It's that sort of thing I am eluding to when I say safety critical items need to meet OE specification (they could be made by another cheaper manufacturer of course but they need to be "Up to spec" ) it's the same with tyres, providing you fit tyres of the OE speed and load rating there will be no problem, but if you fit the same size with a LOWER load rating you COULD (note "could" not will) be in trouble at some stage.

Andy


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## listerdiesel (Aug 3, 2012)

It's amazing how different parts are priced.

Britpart do a set of four gas telescopic dampers for the Discovery 2 at about £33 plus VAT each.

The vehicle is getting on for 2.8 tonnes loaded, so getting on for motorhome weight.

Compare that with what is charged for comparable Motorhome parts.

I'd buy after-market every time. 

Peter


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## erneboy (Feb 8, 2007)

You said "the ones specified by" Ploddy. Not parts meeting the spec given by. I was suggesting that manufacturers would almost without exception specify only their own parts, which I assume you wouldn't dispute? Alan.


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## Pudsey_Bear (Sep 25, 2008)

Mrplodd said:


> Erneboy
> 
> Nope, because original equipment is exactly that, original equipment.
> 
> ...


Just a small thing Andy, but I've always thought fuses were to protect the wiring NOT the appliance.


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## greygit (Apr 15, 2007)

Years and years ago when a young mechanic I used to tune up cars and one of the first thing to go when thinking of the road handling was the original shock absorbers. To keep to original equipment is not always, IMO, the best option and its defiantly more expensive.


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## Pudsey_Bear (Sep 25, 2008)

OEM is always down down to a price and up to a spec which will do usually, aftermarkets stuff can often be better quality, this applies to most things on the market.


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